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1, incognito [,ɪnkɒg'niːtəʊ; ɪn'kɒgnɪtəʊ] n. 匿名者；微行者adj. 改名的；微行的；隐名埋姓的adv. 隐姓埋名地2, lecture ['lektʃə]n. 演讲；讲稿；教训vt. 演讲；训诫vi. 讲课；讲演3, alliance [ə'laiəns]n. 联盟，联合；联姻4, hippo ['hipəu]n. 河马；吐根hippo: 河马| 希波| 希坡5, renegade ['reniɡeid]n. 叛徒；变节者；脱党者vi. 背叛；脱离adj. 叛徒的；背弃的；脱离的6, Cinderella [,sində'relə]n. 灰姑娘（童话中的一个形象）7, clutter ['klʌtə]n. 杂乱，混乱vt. 使凌乱；胡乱地填满8, pants [pænts]n. 裤子；短裤pants: 裤子| 腿甲| 短裤9, attendee [æten'diː]n. 出席者；在场者10, horn [hɔ:n]n. 喇叭n.(牛、羊等的)角, 喇叭, 触角v.装角11, managing ['mænidʒiŋ]v. 管理；设法对付（manage的ing形式）adj. 管理的；节约的；爱管闲事的12, warehouse ['wεəhaus, 'wεəhauz, -haus] n. 仓库；货栈；大商店vt. 储入仓库；以他人名义购进（股票）13, tactful ['tæktful]adj. 机智的；圆滑的；老练的14, predator ['predətə]n. [动] 捕食者；[动] 食肉动物；掠夺者15, celebrity [si'lebrəti]n. 名人；名声16, ironic [ai'rɔnik,-kəl]adj. 讽刺的；反话的17, psychology [psai'kɔlədʒi]n. 心理学；心理状态18, joke [dʒəuk]n. 玩笑，笑话；笑柄vt. 开…的玩笑vi. 开玩笑19, in shock休克；处于极度震惊状态in shock: 休克20, cleavage ['kli:vidʒ]n. 劈开，分裂；[矿]解理；[医]卵裂21, thun der ['θʌndə]n. 雷；轰隆声；恐吓vt. 轰隆地发出；大声喊出vi. 打雷；怒喝22, contagious [kən'teidʒəs]adj. 感染性的；会蔓延的23, essential [ɪ'senʃ(ə)l]n. 本质；要素；要点；必需品adj. 基本的；必要的；本质的；精华的24, Emerald SeaEmerald Sea: 翡翠轩25, animation [,æni'meiʃən]n. 活泼，生气；激励；卡通片绘制26, duplicate ['dju:plikət, 'dju:plikeit]n. 副本；复制品adj. 复制的；二重的vt. 复制；使加倍vi. 复制；重复27, comic ['kɔmik]adj. 喜剧的；滑稽的；有趣的n. 连环漫画；喜剧演员；滑稽人物28, nexus ['neksəs]n. 关系；连结，连系29, locust ['ləukəst]n. [植保] 蝗虫，[昆] 蚱蜢30, sleeve [sli:v]n. [机] 套筒，[机] 套管；袖子，[服装] 袖套vt. 给装袖子；给装套筒sleeve: 袖子| 套筒| 衣袖31, WingsuitWingsuit: 滑翔衣32, stupidity [stʃʊ'pɪdɪtɪ; stʃuː'pɪdɪtɪ; stjʊ'pɪdɪtɪ; stjuː'pɪdɪtɪ]n. 愚蠢；糊涂事33, goddess ['gɔdis]n. 女神34, sunglasses ['sʌn,ɡlɑ:siz, -,ɡlæ-]n. 太阳镜；凸透镜（sunglass的复数）Sunglasses: 太阳镜| 太阳眼镜| 墨镜35, worship ['wə:ʃip]n. 崇拜,礼拜v. 崇拜,敬仰vi. 做礼拜vt. 崇拜36, evolution [,i:və'lu:ʃən, ,ev-]n. 演变；进化论；进展37, smelly ['smeli]adj. 有臭味的，发臭的smelly: 难闻的|臭的|发臭的Smelly Feet: 臭脚丫smelly cage: 难闻的笼子38, soundtrack ['saundtræk]n. 声带；声道；声迹；电影配音39, chill out冷静，冷静下来40, paradox ['pærədɔks]n. 悖论，反论；似非而是的论点；自相矛盾的人或事41, dosing ['dəusiŋ]n. 定量给料，配量；精密分注42, urge [ə:dʒ]n. 强烈的欲望，迫切要求；推动力vi. 强烈要求vt. 力劝，催促；驱策，推进43, Fatalen. 爱情重伤；命中注定（电影名）44, Smurfsn. 蓝精灵（漫画形象）45, defender [dɪ'fɛndɚ]n. 防卫者，守卫者；辩护者；拥护者；卫冕者46, condometricCondometric: 避孕套尺47, turbidity [tə:'bidəti, tə:'biditi]n. [分化] 浊度；浑浊；混浊度；混乱48, blower ['bləuə]n. 鼓风机，吹风机；吹制工；<俚>爱吹牛的人49, compatibility [kəm,pætə'biləti]n. [计] 兼容性50, underprivileged [,ʌndə'privilidʒd]adj. 贫困的；被剥夺基本权力的；社会地位低下的underprivileged: 被剥夺基本权力的| 贫困的| 特权少的51, innovate ['inəuveit]vi. 创新；改革；革新vt. 改变；创立；创始；引人52, tomb [tu:m]n. 坟墓；死亡vt. 埋葬53, persuasively [pə'sweisivli]adv. 令人信服地；口才好地54, eureka [juə'ri:kə]int. 有了！；找到了！55, practise ['præktis] vt. 实践(使...练习,养成...的习惯)56, wick [wɪk]n. 灯芯，蜡烛心vt. 依靠毛细作用带走57, horny ['hɔ:ni]adj. 角的；角状的；淫荡的58, rival ['raivəl]n. 竞争者；对手vt. 与…竞争；比得上某人vi. 竞争adj. 竞争的59, rejection [ri'dʒekʃən]n. 抛弃；拒绝；被抛弃的东西；[篮球]盖帽60, circuit diagram[电][电子] 电路图；[电子] 线路图61, go nuts发疯；失去理智go nuts: 疯狂62, backhoe ['bæk,həu]n. 反向铲；挖沟机63, relief [ri'li:f]n. 救济；减轻，解除；安慰64, fantasy ['fæntəsi]n. 幻想；白日梦；幻觉adj. 虚幻的vt. 空想；想像vi. 耽于幻想；奏幻想曲（等于phantasy）65, authority [ɔ:'θɔrəti]n. 权威；权力；当局66, stumble ['stʌmbl]vi. 踌躇，蹒跚；失足；犯错vt. 使…困惑；使…绊倒n. 绊倒；蹒跚而行67, fudge [fʌdʒ]n. 软糖；胡说；谎话vt. 捏造；粗制滥造；回避vi. 逃避责任；欺骗；蒙混int. 胡说八道！68, grey [ɡrei]adj. 灰色的；灰白的vt. 使变成灰色；使变老vi. 变成灰色；老化n. 灰色69, mention ['menʃən]vt. 说起；提到，谈到；提及，论及n. 提及，说起70, dati ng ['deitiŋ]n. 约会71, trial ['traiəl]n. 试验；审讯；努力；磨炼adj. 试验的；审讯的72, ridiculous [ri'dikjuləs]adj. 可笑的；荒谬的73, heck [hek]n. 饲草架int. 真见鬼（hell的委婉说法）74, Princess PearlPrincess Pearl: 还珠格格III75, tilt [tilt]vi. 倾斜；翘起；以言词或文字抨击vt. 使倾斜；使翘起n. 倾斜76, nightstand ['naitstænd]n. （美）床头几（等于night table）nightstand: 床头灯架| 床头柜77, drainage ['dreinidʒ]v. 排水n. 排水系统,污水78, consultant [kən'sʌltənt]n. 顾问；咨询者；会诊医生79, Beatles ['bi:tlz]n. 披头士合唱（摇滚乐队）80, razor ['reizə]vt. 剃，用剃刀刮n. 剃刀81, dental caredental care: 牙齿保健| 口腔保健| 挴 怅翩82, sexual orientation性取向，性倾向；性指向83, drown [draun]vt. 淹没；把…淹死vi. 淹死；溺死84, revolver [ri'vɔlvə, -'vɔ:-]n. 左轮手枪；旋转器85, arouse [ə'raʊz]vt. 引起；唤醒；鼓励vi. 激发；醒来；发奋86, bass [beis]n. 鲈鱼；男低音；低音部；椴树adj. 低音的87, smiley ['smaili]n. 微笑符（等于smily）adj. 微笑的；引起微笑的88, legend ['ledʒənd]n. 传奇；说明；图例；刻印文字89, elegant ['eliɡənt]adj. 高雅的，优雅的；讲究的90, sneer [snɪə]vi. 嘲笑，冷笑vt. 嘲笑，冷笑n. 嘲笑，冷笑91, spiderman ['spaidəmæn]n. 高空作业的建筑工人92, 安乐死[ān lè sǐ]euthanasia93, necktie ['nektaɪ]n. 领带94, cosmology [kɔz'mɔlədʒi]n. [天] 宇宙论，[天] 宇宙学95, ballet ['bælei, bæ'lei]n. 芭蕾舞剧；芭蕾舞乐曲96, arcade [ɑ:'keid]n. 拱廊；（内设投角子电子游戏机等的）游乐场；有拱廊的街道vt. 使有拱廊97, bailout ['beil,aut]n. 紧急救助；跳伞98, resourcesn. 资源；物力（resource的复数）v. 向…提供资金（resource的第三人称单数）99, fancy ['fænsi]n. 幻想；想像力；爱好adj. 想象的；奇特的；昂贵的；精选的vt. 想象；喜爱；设想；自负vi. 幻想；想象100, congress ['kɔŋɡres, kən'ɡres]n. 国会；代表大会；会议；社交101, fetching ['fetʃiŋ]adj. 迷人的；动人的；吸引人的102, consumption [kən'sʌm(p)ʃ(ə)n]n. 消费；消耗；肺痨103, microwave ['maikrəuweiv]n. 微波104, catheterization [,kæθitərai'zeiʃən, -ri'z-]n. [外科] 导管插入105, surgery ['sə:dʒəri]n. 外科；外科手术；手术室；诊疗室106, expensesn. 费用（expense的复数形式）；[会计] 开支v. 向收取费用；被花掉（expense的第三人称单数形式）Expenses: 支出| 经费| 开支107, molasses [mə'læsɪz]n. 糖蜜，糖浆108, march [mɑ:tʃ]n. 行军，进军；进行曲；示威游行vt. 迫使……前进vi. 进军；走过109, sorcery ['sɔ:səri]n. 魔术，巫术110, scramble ['skræmbl]n. 攀缘,争取v. 攀缘,搅炒,混杂一起111, witch [witʃ]n. 巫婆，女巫vt. 迷惑；施巫术112, civilian [si'viljən]adj. 民用的；百姓的，平民的n. 平民，百姓113, affectionate [ə'fekʃənət]adj. 深情的；充满深情的114, composition [,kɔmpə'ziʃən]n. 作文，作曲；[材] 构成；合成物115, perspective [pə'spektɪv]n. 观点；远景；透视图adj. 透视的116, widespread ['waid'spred]adj. 普遍的，广泛的；分布广的117, overall ['əuvərɔ:l]a. 全部的,全体的,一切在内的ad. 总的来说,全部地118, dement [di'ment]n. 痴呆症adj. 疯狂的vt. 使发狂119, creepy ['kri:pi]adj. 令人毛骨悚然的；爬行的120, vital ['vaɪt(ə)l]adj. 至关重要的；生死攸关的；有活力的121, perigee ['peridʒi:]n. 近地点122, pumpkin ['pʌmpkin]n. 南瓜123, align [ə'lain]vt. 使结盟；使成一行；匹配vi. 排列；排成一行124, canvas ['kænvəs]n. 帆布adj. 帆布制的vt. 用帆布覆盖，用帆布装备125, vitae ['vi:tai]n. 个人简历；血液（vita的复数形式）126, overalls ['əuvərɔ:lz]n. [美]工装裤,工作裤127, fumble ['fʌmbl]n. 摸索；笨拙的处理；漏球vi. 摸索；笨拙地行动；漏球vt. 摸索；笨拙地做；漏接128, bitchy ['bitʃi]adj. 恶毒的；暴躁的；犯贱的129, maple ['meipl]n. 枫树；淡棕色130, coaxial ['kəu'æksəl]adj. 同轴的，共轴的131, proximity [prɔk'simiti]n. 亲近，接近；[数] 邻近132, particularly [pə'tikjuləli]adv. 特别地，独特地；详细地，具体地；明确地，细致地133, contextualization [kɔn,tekstjuəlai'zeiʃən]n. 情境化；处境化；语境化；把握语境134, involved [in'vɔlvd]adj. 有关的；卷入的；复杂的v. 涉及；使参与；包含（involve的过去式和过去分词）involved: 被火和烟包围的| 棘手的| 有关的135, testes ['testi:z]n. 睾丸（testis的复数）136, spam [spæm]n. 垃圾邮件；罐头猪肉137, chronicle ['krɔnikl]n. 编年史，年代记；记录vt. 记录；把…载入编年史138, sidewalk ['saidwɔ:k]n. 人行道139, panic attack惊恐发作（一种病症）Panic Attack: 恐怖袭击| 惊恐发作| 恐慌发作140, justice ['dʒʌstis]n. 司法，法律制裁；正义；法官，审判员141, grab [græb]n. 抓握,接应,掠夺v. 抓取,抢去142, Sheldon ['ʃeldən]n. 谢尔登（男子名）143, cushy ['kuʃi]adj. 轻松的；容易的；轻松又容易赚钱的144, take a dump上大号；大便take a dump: 上大号145, evidence ['evidəns]n. 根据,证据146, insider [,in'saidə]n. 内部的人，会员；熟悉内情者147, occasion [ə'keiʒən, əu-]n. 时机，机会；场合；理由vt. 引起，惹起148, fare [fєə]n. 费用,食物v. 进展,进步,经营149, unicorn ['ju:nikɔ:n]n. 独角兽；麒麟150, disturb [dis'tə:b]v. 扰乱,妨碍,使...不安151, lag [læɡ]n. 落后；迟延；防护套；囚犯；桶板adj. 最后的vi. 滞后；缓缓而行；蹒跚vt. 落后于；押往监狱；加上外套152, controversy ['kɒntrəvɜːsɪ; kən'trɒvəsɪ] n. 争论；论战；辩论153, ecstasy ['ekstəsi]n. 狂喜；入迷；忘形154, tuxedo [tʌk'si:du]n. 男士无尾半正式晚礼服；无尾礼服155, focal length[光][摄] 焦距156, flute [flu:t]n. 长笛vt. 用长笛吹奏vi. 吹长笛157, especially [i'speʃəli]adv. 特别；尤其；格外158, coal [kəʊl]n. 煤；煤块；木炭vt. 给…加煤；把…烧成炭vi. 上煤；加煤159, storyline ['stɔ:ri,lain]n. 故事情节160, creek [kri:k]n. 小溪；小湾161, infection [in'fekʃən]n. 感染；传染；影响；传染病162, fuel ['fjuəl]vi. 得到燃料vt. 供以燃料，加燃料n. 燃料；刺激因素163, sandals [sændlz]n. 凉鞋；拖鞋（sandal的复数）；便鞋v. 使穿凉鞋（sandal的第三人称单数）164, latte ['lɑ:tei]n. 拿铁咖啡，拿铁165, universal [,ju:ni'və:səl]adj. 普遍的；通用的；宇宙的；全世界的；全体的n. 一般概念；普通性166, offset ['ɒfset]n. 抵消，补偿；平版印刷；支管vt. 抵消；弥补；用平版印刷术印刷vi. 装支管167, confrontingv. 面对；对抗（confront的ing形式）；对立168, activity [æk'tivəti]n. 活动；行动；活跃169, onion ['ʌnjən]n. 洋葱170, quarrel ['kwɔ:rəl]vi. 吵架；争论；挑剔n. 吵架；反目；怨言；争吵的原因；方头凿171, breast tissuebreast tissue: 乳腺组织172, diver ['daivə]n. 潜水者；跳水的选手；潜鸟173, constant ['kɔnstənt]n. [数] 常数；恒量adj. 不变的；恒定的；经常的174, obsolete ['ɔbsəli:t]a. 已废弃的,过时的175, assigned [ə'saind]adj. 指定的；已分配的v. 分配（assign的过去分词）；指定；委派176, inflamed [ɪn'flemd]adj. 发炎的；红肿的v. 使发炎（inflame的过去分词）；使燃烧；使火红；激起177, destiny ['destini]n. 命运，定数，天命178, brittle ['brɪt(ə)l]adj. 易碎的，脆弱的；易生气的179, compromisedv. 妥协；连累（compromise的现在分词）adj. 妥协的；妥协让步的，缺乏抵抗力的180, forge [fɔːdʒ]n. 熔炉，锻铁炉；铁工厂vt. 伪造；锻造vi. 伪造；做锻工181, annotate ['ænəteɪt]vt. 注释；作注解vi. 注释；给…作注释或评注182, lubricant ['lu:brikənt]n. 润滑剂；润滑油adj. 润滑的183, centrifuge ['sentrifju:dʒ]n. 离心机；[机][化工] 离心分离机vt. 用离心机分离；使…受离心作用184, space shuttle185, fluidized ['flu:idaizd]adj. 流态化的；沸腾的v. 液化（fluidize的过去分词）186, vulnerabilitiesn. 缺陷（vulnerability的复数形式）；脆弱点187, informed [in'fɔ:md]v. 通知；使了解；提供资料（inform的过去分词）adj. 消息灵通的；见多识广的informed: 见多识广的| 通知| 告知188, securely [si'kjuəli]adv. 安全地；牢固地；安心地；有把握地189, wicked ['wɪkɪd]adj. 邪恶的；恶劣的；不道德的；顽皮的190, confront [kən'frʌnt]vt. 面对；遭遇；比较191, sensual ['sensjuəl, -ʃuə-]adj. 感觉的；肉欲的；世俗的；感觉论的192, syllable ['siləbl]n. 音节vt. 划分音节vi. 按音节发音；讲话193, phew [fju:, pfju:]int. 唷（表示不快、惊讶的声音）vi. 咂舌头194, bullying ['buliiŋ]n. 恃强欺弱的行为v. 期负（bully的现在分词）195, entire [in'taiə]adj. 全部的，整个的；全体的196, flush [flʌʃ]n. 激动，洋溢；面红；萌芽；旺盛；奔流adj. 大量的；齐平的；丰足的，洋溢的；挥霍的vt. 使齐平；发红，使发亮；用水冲洗；使激动vi. 发红，脸红；奔涌；被冲洗197, intermittent [,intə'mitənt]adj. 间歇的，断断续续的198, dense [dens]adj. 稠密的；浓厚的；愚钝的199, sneak [sni:k]n. 鬼鬼祟祟的人；偷偷摸摸的行为；告密者adj. 暗中进行的vi. 溜；鬼鬼祟祟做事；向老师打小报告vt. 偷偷地做；偷偷取得200, lobby ['lɔbi]n. 大厅；休息室；会客室；游说议员的团体vt. 对……进行游说vi. 游说议员201, biohazard ['baɪəʊ,hæzəd]n. 生物危害202, somehow ['sʌmhau] ad. 不知怎么地,设法203, fondu ['fɔndu:]n. 溶化奶油adj. 颜色等会混和的204, phobia ['fəubiə, -bjə]n. 恐怖，憎恶；恐惧症205, feral ['fiərəl]adj. 野生的；凶猛的；阴郁的206, slogan ['sləuɡən]n. 标语；呐喊声207, stroke [strəuk]n. 中风；冲程；笔画；打击；尝试；轻抚vt. 抚摸；敲击；划尾桨；划掉vi. 击球；作尾桨手；敲击键盘208, supremacist [sju'preməsist, sə-]n. 至上主义者adj. 至上主义者的209, awesome ['ɔ:səm]adj. 可怕的，引起敬畏的210, chronograph ['krɔnəuɡrɑ:f]n. 记时计；记秒表211, blend [blend]vt. 混合vi. 混合；协调n. 混合；掺合物212, penis ['pi:nis]n. 阳物；[解剖] 阴茎penis: 阴茎|阳具|阳物penis bone: 阴茎骨penis cervi: 梅鹿鞭213, desperate ['despərət]adj. 不顾一切的；令人绝望的；极度渴望的214, overdress [,əuvə'dres, 'əuvədress]vt. 过度装饰；使穿著过分讲究vi. 穿得过分讲究；穿得过多n. [服装] 外衣215, carrier ['kæriə]n. 载体；货架；运送者；带菌者216, addict [ə'dikt]n. 有瘾的人；入迷的人vt. 使上瘾；使沉溺217, mechanical [mi'kænikl]a. 机械的,力学的,呆板的218, consistsv. 由…构成；由…组成（consist的三单形式）219, aided ['eidid]adj. 辅助的；[自] 半自动的v. 帮助（aid的过去分词）220, bam [bæm]vt. 欺骗vi. 欺骗n. 哄骗221, self-portrait ['self'pɔ:tr(e)it]n. 自画像222, preparation [,prepə'reɪʃ(ə)n]n. 预备；准备223, identify [ai'dentifai]v. 识别,认明,鉴定224, numerous ['nju:mərəs]adj. 许多的，很多的225, treadmill ['tredmil]n. 踏车，跑步机；单调的工作226, privacy ['praivəsi, 'pri-, 'prai-]n. 隐私；秘密；隐居；隐居处227, recommendation [,rekəmen'deiʃən]n. 推荐,介绍228, dairy ['dεəri]n. 奶制品；乳牛；制酪场；乳品店；牛奶及乳品业adj. 乳品的；牛奶的；牛奶制的；产乳的229, slappedv. 侮辱；拍击；掴耳光（slap的过去分词）adj. 被掴耳光的slapped: 被掴的230, Cialisn. 西力士（又名犀利士，壮阳药）231, Taikonaut [taikɔnɔ:t]n. （汉）中国宇航员（由汉语拼音taikong和astronaut缩合而成）232, distribution [dɪstrɪ'bjuːʃ(ə)n]n. 分布；分配233, robe [rəub]n. 长袍，礼服；制服vi. 穿长袍vt. 使穿长袍234, dominant ['dɔminənt]n. 显性adj. 显性的；占优势的；支配的，统治的235, warrior ['wɔriə, 'wɔ:-]n. 战士，勇士；鼓吹战争的人236, criterion [kraɪ'tɪərɪən]n. （批评判断的）标准；准则；规范；准据237, category ['kætɪg(ə)rɪ]n. 种类，分类；[数] 范畴238, sights [saits]n. 风景，名胜；视野（sight的复数）v. 瞄准（sight的第三人称单数）；仔细观看239, session ['seʃ(ə)n]n. 会议；（法庭的）开庭；（议会等的）开会；学期；讲习会240, brocolli 241, needle ['ni:dl]n. 针；指针；刺激；针状物vi. 缝纫；做针线vt. 刺激；用针缝242, bravery ['breivəri]n. 勇敢；勇气243, huddle ['hʌdl]n. 拥挤；混乱；杂乱一团vt. 把...挤在一起；使缩成一团；草率了事vi. 蜷缩；挤作一团244, roam [rəʊm]vi. 漫游，漫步；流浪vt. 在…漫步，漫游；在…流浪n. 漫步，漫游；流浪245, maturity [mə'tjuəriti]n. 成熟；到期；完备246, oxygen ['ɔksidʒən]n. [化学] 氧气，[化学] 氧247, roar [rɔ:]n. 吼,咆哮,轰鸣v. 吼,大声说出,叫喊248, Syria ['si:riə; 'si-]n. 叙利亚共和国249, Ireland ['aiəland]n. 爱尔兰250, cruel [krʊəl]adj. 残酷的，残忍的；使人痛苦的251, anonymous [ə'nɔniməs]adj. 匿名的，无名的；无个性特征的252, reservoir ['rezəvwɑ:]n. 水库；蓄水池253, subscribe [səb'skraib]vi. 订阅；捐款；认购；赞成；签署vt. 签署；赞成；捐助254, quiz [kwiz]n. 考查；恶作剧；课堂测验vt. 挖苦；张望；对…进行测验255, unmount ['ʌnmaunt]n. 卸载；取消安装256, adjust [ə'dʒʌst]vt. 调整，使…适合；校准vi. 调整，校准；适应257, testis ['testis]n. [解剖] 睾丸（等于testical的复数）258, foreseeable [fɔr'siəbl]adj. 可预知的；能预测的259, hierarchy ['haiə,rɑ:ki]n. 层级；等级制度260, squash [skwɔʃ, skwɔ:ʃ]n. 壁球；挤压；咯吱声；南瓜属植物；（英）果汁饮料vt. 镇压；把…压扁；使沉默vi. 受挤压；发出挤压声；挤入261, construction [kən'strʌkʃən]n. 建设；建筑物；解释；造句262, murk [mɜːk]n. 黑暗；阴沉，阴郁adj. 阴郁的；黑暗的263, melt [melt]vi. 熔化，溶解；渐混vt. 使融化；使熔化；使软化；使感动n. 熔化；熔化物264, concentration [,kɔnsən'treiʃən]n. 浓度；集中；浓缩；专心；集合265, peaceful ['pi:sful]adj. 和平的，爱好和平的；平静的266, criteria [krai'tiəriə]n. 标准，条件（criterion的复数）267, recipients [ri'sipiənt]n. 收件人（recipient的复数）268, marketing ['mɑ:kitiŋ]n. 行销，销售v. 出售；在市场上进行交易；使…上市（market的ing形式）269, vendor ['vendə; 'vendɔː]n. 卖主；小贩；[贸易] 自动售货机270, ostrich ['ɔ:stritʃ, 'ɔ-]n. 鸵鸟；鸵鸟般的人271, yummy ['jʌmi]adj. 好吃的；美味的；愉快的n. 美味的东西；令人喜爱的东西272, fantastic [fæn'tæstik]a. 极好的,难以相信的,奇异的,幻想的273, Adolf Hitler阿道夫希特勒（纳粹领袖）274, dioxide [daɪ'ɒksaɪd]n. 二氧化物275, machine gun[军] 机关枪276, lackey ['læki]n. 男仆；侍从；马屁精vt. 侍候，服侍；奉承277, Pericles ['perikli:z]n. 伯里克利（古雅典政治家）278, pee [pi:]n. 尿；撒尿vi. 撒尿vt. 小便279, alien ['eiljən] n. 外国人，外侨；外星人adj. 外国的；相异的，性质不同的；不相容的vt. 让渡，转让280, finance [fai'næns]n. 财政，财政学；金融vt. 负担经费，供给…经费vi. 筹措资金281, thrill methrill me: 威胁我| 抱我282, square [skwεə]n. 平方；广场；正方形adj. 平方的；正方形的；直角的；正直的vt. 使成方形；与…一致vi. 一致；成方形adv. 成直角地283, settle ['setl]n. 有背长椅vi. 解决；定居；沉淀；下陷vt. 解决；安排；使…定居284, whale [hweil]vt. 猛揍；使惨败vi. 捕鲸n. 鲸；巨大的东西285, Norway ['nɔ:wei]n. 挪威（北欧国家名）286, LACES [leisiz]abbr. 工程学会洛杉矶委员会（Los Angeles Council of Engineering Societies）287, warning ['wɔ:niŋ]n. 警告；预兆；预告adj. 警告的；引以为戒的v. 警告（warn的ing形式）288, annual leave[劳经] 年度假289, mustard ['mʌstəd]n. 芥末；芥菜；深黄色；强烈的兴趣290, faintest ['feintist]adj. 一点也不的（用于否定句，加强语气）；极小的291, snap [snæp]vt. 突然折断，拉断；猛咬；啪地关上vi. 咬；厉声说；咯嗒一声关上n. 猛咬；劈啪声；突然折断adj. 突然的292, sludge [slʌdʒ]n. 烂泥；泥泞；泥状雪；沉淀物；（海上）小浮冰293, ecosystem ['i:kəu,sistəm, 'ekəu-]n. 生态系统294, hip [hip]n. 臀部,屋脊,忧郁295, intense [in'tens]adj. 强烈的；紧张的；非常的；热情的296, spittle ['spitl]n. 唾沫；吐出的泡沫297, reluctantlyad. 不情愿地, 嫌恶地298, pram [prɑ:m, præm]n. 婴儿车；送牛奶用的手推车PRAM: 相变内存| 婴儿车| 记忆体299, furniture ['fə:nitʃə]n. 家具300, pessimist ['pesimist]n. 悲观主义者301, pretext ['pri:tekst]n. 借口；托辞vt. 以…为借口302, sneak in淡入，渐显303, smear [smiə]vt. 弄脏；涂上；诽谤；把…擦模糊n. 涂片；污点；诽谤vi. 被弄脏304, mule [mju:l]n. 骡；倔强之人，顽固的人；杂交种动物305, retreat [ri'tri:t]n. 撤退；休息寓所；撤退vt. 退（棋）；使后退vi. 撤退；退避；向后倾306, Passion ['pæʃən]n. 耶稣受难记；耶稣受难的艺术或音乐作品307, slicing ['slaisiŋ]n. 切断，切片；限制，[电子] 限幅slicing: 切片| 分层开采| 刨切308, rearrange [,ri:ə'reindʒ]vt. 重新排列；重新整理rearrange: 重新安排| 调整| 重新整理309, joint [dʒɔint]n. 关节；接缝；接合处，接合点；（牛，羊等的腿）大块肉adj. 共同的；连接的；联合的，合办的vt. 连接，贴合；接合；使有接头vi. 贴合；生节310, punch [pʌntʃ]n. 冲压机；打洞器；钻孔机vt. 开洞；以拳重击vi. 用拳猛击311, wrap [ræp]n. 披肩,围巾v. 覆盖,包围,裹,包n. 包裹vt. 包,裹312, onto ['ɔntu, -tə]prep. 在…之上；对…了解；[数]映射到…上adj. [数]映成的；映射的；自身的313, approve [ə'pru:v]vi. 批准；赞成；满意vt. 批准；赞成；为…提供证据314, occupation [,ɔkju'peiʃən]n. 职业；占有；消遣；占有期315, reviewsn. 综述；评论；复习（review的复数）；复核v. 回顾；复习（review的三单形式）；检验316, philosophy [fi'lɔsəfi, fə-]n. 哲学；哲理；人生观317, peripheral [pə'rifərəl]adj. 外围的；次要的318, embedded [ɪm'bɛd]adj. 嵌入式的；植入的；内含的v. 嵌入（embed的过去式和过去分词形式）319, countless ['kauntlis]adj. 无数的；数不尽的320, rainforest ['rein,fɔrist]n. （热带）雨林321, viagra [vai'æɡrə, vi:'æɡrə]n. 伟哥（一种治疗阳痿的药，壮阳药）；万艾可322, blackberry ['blækbəri]n. 黑莓323, nelly ['neli]n. 傻瓜；女性化的同性恋者；大海鸟adj. 女子气的324, console [kən'səul]n. [计] 控制台；[电] 操纵台vt. 安慰；慰藉325, seagull ['si:gʌl]n. 海鸥326, panic ['pænik]n. 恐慌，惊慌；大恐慌adj. 恐慌的；没有理由的vt. 使恐慌vi. 十分惊慌327, bless [bles]vt. 祝福；保佑；赞美328, cursing ['kə:siŋ]v. 诅咒（curse的ing形式）cursing: 诅咒329, bet [bet]n. 打赌，赌注；被打赌的事物vt. 打赌；敢断定，确信vi. 打赌330, ripple ['ripl]n. 波纹；涟漪；[物] 涟波vi. 起潺潺声vt. 在…上形成波痕331, Lesbian ['lezbiən]n. 女同性恋者adj. 女同性恋的332, trolling ['trəuliŋ]n. 拖捕的行为v. 高声地唱；旋转；拖钓（troll的ing形式）333, necklace ['neklis]n. 项链334, tiny ['taini]adj. 微小的；很少的335, permanent residence长期居留336, explore [iks'plɔ:]v. 探险,探测,探究[计算机] 探讨337, trailer ['treilə]n. 预告片；拖车；追踪者vi. 乘拖车式活动房屋旅行vt. 用拖车载运338, ashtray ['æʃtrei]n. 烟灰缸339, expansion [iks'pænʃən]n. 扩大,膨胀340, AutofellatioAutofellatio: 男性自我口交341, clot [klɔt]n. [生理] 凝块vi. 凝结vt. 使凝结成块342, digest [di'dʒest, dai-, 'daidʒest]n. 文摘；摘要vt. 消化；吸收；融会贯通vi. 消化343, bubble wrap气泡膜外包装材料344, armpit ['ɑ:mpit]n. 腋窝345, vale [veil]n. 谷；溪谷int. 再见；再会346, beancurd ['bi:nkə:d]n. 豆腐347, Newcastle ['nju:,kɑ:sl]n. 纽卡斯尔(英国港市)348, Nepal [ni'pɔ:l; -'pɑ:l] n. 尼泊尔（亚洲国家）349, tolerate ['tɔləreit]vt. 忍受；默许；宽恕350, nope [nəup]adv. 不是，没有；不351, prosperous ['prɔspərəs]a. 繁荣的,兴旺的352, arrestn. 逮捕,监禁v. 拘捕,妨碍,吸引353, gorgeous ['gɔːdʒəs]adj. 华丽的，灿烂的；极好的354, reconstruct ['ri:kən'strʌkt]v. 重建,改造,复兴355, snuggery ['snʌg(ə)rɪ]n. 温暖舒适的地方，舒适的家356, alto ['æltəu]n. 女低音；男声最高音；中音乐器adj. 中音部的357, caramel ['kærəmel]n. 焦糖；饴糖；焦糖糖果358, gap year空档年；间隔年359, revenue ['revənju:, -nu:]n. 税收，国家的收入；收益360, superhero ['sju:pə,hiərəu]n. 超级英雄361, lickern. 舔食者；很讨厌的人362, applaud [ə'plɔ:d]vt. 向…喝采；赞同；称赞vi. 喝彩；鼓掌欢迎363, vocabulary [vəu'kæbjuləri]n. 词汇；词表364, looter ['lu:tə]n. 抢劫者365, fiance [fi'ɔnsei]n. 未婚夫366, dive ['di:vei, daiv]vi. 跳水；潜水；俯冲；急剧下降n. 潜水；跳水；俯冲；扑367, instrument ['instrumənt, 'instrə-, -ment]n. 仪器；工具；乐器；手段；器械368, donation [dəu'neiʃən]n. 捐款，捐赠物；捐赠369, bikram yogabikram yoga: 热瑜伽| 高温瑜伽| 比克若姆瑜伽370, paradise ['pærədaɪs]n. 天堂371, mermaid ['mə:meid]n. 美人鱼（传说中的）；女子游泳健将372, suffix ['sʌfiks, sə'fiks]n. 后缀；下标vt. 添后缀373, sexually ['sekʃuəli]adv. 性别地；两性之间地374, rendering ['rend(ə)rɪŋ]n. 翻译；表现；表演；描写；打底；（建筑物等）透视图vt. 致使；表演；打底（render的ing形式）vi. 给予补偿（rendr的ing形式）375, rim [rim]n. 边，边缘；轮辋；圆圈vt. 作…的边，装边于vi. 作…的边，装边于376, implementation [,implimen'teiʃən]n. [计] 实现；履行；安装启用377, sibling ['sibliŋ]n. 兄弟姊妹；民族成员378, scientific [,saiən'tifik]adj. 科学的，系统的379, auran. 气味,气氛380, fatty tissue脂肪组织381, primer ['praimə, 'pri-]n. 初级读本；识字课本；原始物382, velvet ['velvit]n. 天鹅绒a. 天鹅绒的383, inequality [,ini'kwɔləti]n. 不平等；不同；不平均384, date from追溯到；始于；起源于385, San Diego圣迭哥，圣地亚哥（美国加州港口城市）386, abductee [,æbdʌk'ti:]n. 被绑架者387, handset ['hændset]n. 手机，电话听筒388, clinic ['klinik]n. 诊所；临床389, inevitable [in'evitəbl]adj. 必然的，不可避免的390, dismount [,dis'maunt]vt. 下车；使下马；使掉下vi. 下马；下车n. 下马；下车391, cope [kəup] n. 长袍vi. 处理；对付；竞争392, chop suey ['tʃɔp'su:i]杂碎；炒杂烩菜393, ameba [ə'mi:bə]n. 变形虫；[无脊椎] 阿米巴394, vertigo ['və:tiɡəu]n. 晕头转向，[临床] 眩晕395, lickvi. 舔；轻轻拍打vt. 舔；卷过；鞭打vt. （非正式）战胜n. 舔；打；少许396, formerly ['fɔːməlɪ]adv. 以前；原来397, shelter ['ʃeltə]n. 庇护；避难所；遮盖物vt. 保护；使掩蔽vi. 躲避，避难398, slideshown. 幻灯片放映399, nutter ['nʌtə]n. 疯子；拾坚果的人400, unknowingly401, tenor ['tenə]n. 男高音；要旨，大意；票据的限期；稳定的进程adj. 男高音的402, calligraphy [kə'liɡrəfi]n. 书法；笔迹403, orgasm ['ɔ:ɡæzəm]n. [生理] 性高潮；极度兴奋404, prostitute ['prɔstitju:t]vt. 使沦为妓女adj. 卖淫的；堕落的n. 妓女405, cutlet ['kʌtlɪt]n. 肉片；炸肉排；炸肉片406, bundle ['bʌndl]n. 束；捆vt. 捆vi. 匆忙离开407, hunt [hʌnt]n. 狩猎,追捕,搜寻v. 狩猎,打猎,搜索408, Serengeti [,serən'ɡeti]n. 塞伦盖蒂平原（位于坦桑尼亚西北部）409, feature ['fi:tʃə]n. 特征,容貌n. 特点,特色,特性410, hovercraft ['hɔvəkrɑ:ft, -kræft]n. 气垫船411, hibernate ['haɪbəneɪt]vi. 过冬；（动物）冬眠；（人等）避寒412, integrate ['intiɡreit, 'intiɡrit, -ɡreit]n. 一体化；集成体adj. 整合的；完全的vi. 求积分；取消隔离；成为一体vt. 使…完整；使…成整体；求…的积分；表示…的总和413, sour ['sauə]adj. 酸的；酸臭的；讨厌的；刺耳的；发酵的vi. 变酸；厌烦；发酵vt. 使失望；使变酸n. 酸味；苦事414, adequate ['ædikwit]adj. 充足的；适当的；胜任的415, gorilla [ɡə'rilə]n. [动]大猩猩416, mutilatedadj. 残缺的；破坏的v. 切断；使残废（mutilate的过去分词）417, yum [jʌm]int. 极好的；妙的；美味的418, drafting ['drɑ:ftiŋ, 'dræft-]n. 起草；制图；拖拽v. 起草；挑选；脱去（draft的ing形式）419, yup [jʌp]int. 是的（等于yes）420, aperture ['æpə,tjuə]n. 孔，穴；（照相机，望远镜等的）光圈，孔径；缝隙421, convince [kən'vins]v. 说服,使...相信422, observer [əb'zə:və, ɔb-]n. 观察者；[天] 观测者；遵守者423, breast milk母乳；母奶424, gliding ['ɡlaidiŋ]adj. 滑行的；流畅的；滑顺的v. 滑翔；消逝；溜走（glide的ing形式）425, temple ['templ]n. 庙宇,寺院426, marvelous ['mɑ:viləs]adj. 了不起的；非凡的；令人惊异的；不平常的427, dagoba ['dɑ:ɡəbə]n. （印度的）舍利塔；佛骨堂428, gardener ['ɡɑ:dənə]n. 园丁；花匠；园艺家429, hamper ['hæmpə] vt. 妨碍；束缚；使困累n. 食盒，食篮；阻碍物430, swear [swεə]n. 宣誓；诅咒vt. 发誓；咒骂vi. 发誓，宣誓；诅咒431, pregnant ['preɡnənt]adj. 怀孕的；富有意义的432, preg [preɡ]adj. 怀孕的433, crane [krein]n. 吊车，起重机；鹤vt. 用起重机起吊；伸长脖子vi. 伸着脖子看；迟疑，踌躇434, bikramBikram: 比克拉姆| 热瑜伽| 高温瑜伽435, courteous ['kə:tjəs]adj. 有礼貌的；谦恭的436, co-existencen. 共生；共存性437, buddy ['bʌdi]n. 伙伴，好朋友；密友；小男孩vi. 做好朋友，交朋友buddy: 合作者| 凌一凡| 密友438, ugly ['ʌɡli]adj. 丑陋的；邪恶的；令人厌恶的439, artifice ['ɑ:tifis]n. 诡计；欺骗；巧妙的办法440, malicious [mə'lɪʃəs]adj. 恶意的；恶毒的；蓄意的；怀恨的441, femenfemen: 唇寒齿亡| 乌克兰女权团体442, wildlife ['waildlaif]n. 野生动植物adj. 野生动植物的443, chase [tʃeɪs]n. 追逐；追赶；追击vt. 追逐；追捕；试图赢得；雕镂vi. 追逐；追赶；奔跑444, whore [hɔ:]vi. 卖淫，娼妓n. 娼妓，淫妇445, Antarctic [æn'tɑ:ktik]a. 南极的n. (the A-)南极洲,南极圈446, laundry ['lɔːndrɪ]n. 洗衣店，洗衣房；要洗的衣服；洗熨；洗好的衣服447, babe ['beib]n. 婴儿，小孩；女孩；天真幼稚的人448, iron ['aiən]a. 刚强的n. 铁,熨斗v. 熨,烫,烫衣服vt. 熨烫449, graduation [ɡrædju'eiʃən, -dʒu-]n. 毕业；毕业典礼；刻度，分度；分等级Graduation: 毕业| 分度| 刻度450, strike [straik]n. 罢工,打击,殴打v. 打,罢工,划燃451, cucumber ['kju:kʌmbə]n. 黄瓜452, adventure [əd'ventʃə, æd-]n. 冒险；冒险精神；投机活动vt. 冒险；大胆说出vi. 冒险453, significant [sig'nifikənt]n. 象征；有意义的事物adj. 重大的；有效的；有意义的；值得注意的；意味深长的454, paranoid ['pærənɔid]n. 患妄想狂的人；偏执狂患者adj. 类似妄想狂的；属于偏执狂的455, proxy ['prɔksi]n. 代理人；委托书；代用品456, relevancen. 中肯；关联；适当457, mimic ['mimik]vt. 模仿，摹拟n. 效颦者，模仿者；仿制品；小丑adj. 模仿的，模拟的；假装的458, sundae ['sʌndei, -di:]n. 圣代冰淇淋459, procedure [prə'si:dʒə]n. 程序，手续；步骤460, ouncesn. 盎司，英两；安士（ounce的复数）461, snowboard ['snəubɔ:d]n. 滑雪板462, definitely ['definitli]adv. 清楚地，当然；明确地，肯定地463, pinch [pintʃ]n. 匮乏；少量；夹痛vt. 捏；勒索；使苦恼；掐掉某物，修剪vi. 夹痛；节省464, philosopher [fi'lɔsəfə, fə-]n. 哲学家；哲人465, consulting [kən'sʌltiŋ]v. 咨询，请教；商议（consult的现在分词形式）adj. 咨询的，商议的；顾问的，任专职顾问的466, picket ['pikit]n. 警戒哨；纠察队；[建] 尖木桩vt. 派……担任纠察；用尖桩围住vi. 担任纠察467, contrary ['kɔntrəri]n. 相反；反面adj. 相反的；对立的adv. 相反地468, banana split香蕉圣代（剖开香蕉夹以冰淇淋等）；香蕉半剖条469, divide [di'vaid]n. [地理] 分水岭，分水线vt. 划分；除；分开；使产生分歧vi. 分开；意见分歧470, jail [dʒeil]n. 监狱；监牢；拘留所vt. 监禁；下狱471, handful ['hæn(d)fʊl; -f(ə)l]n. 少数；一把；棘手事472, Period painPeriod pain: 经痛473, Dior ['di:ɔ:]n. 迪奥（法国奢侈品牌）474, wrinkle ['riŋkl]n. 皱纹vi. 起皱vt. 使起皱纹475, sticky ['stiki]adj. 粘的；粘性的476, optimist ['ɔptimist]n. 乐观主义者；乐天派477, upcoming ['ʌp,kʌmiŋ]adj. 即将来临的upcoming: 即将来临的| 即将到来的| 预定将要478, challenge ['tʃælindʒ]n. 挑战；怀疑vt. 向…挑战479, presence ['prezəns]n. 存在；出席；参加；风度；仪态480, disobedience [,disə'bi:djəns]n. 不服从；违反，违抗481, nipple ['nipl]n. 乳头，奶头；奶嘴482, oxytocin [,ɔksi'təusin, -'tɔ-]n. [药] 催产素；缩宫素；脑下垂体后叶荷尔蒙之一种483, kindergarten ['kində,ɡɑ:tən]n. 幼儿园；幼稚园484, decentralized [,di:'sentrəlaizd]。
bctb考试词汇大纲由于不太明确“bctb考试”具体是什么考试，没有对应的官方词汇大纲内容，以下为您提供一份按照类似要求（词汇+发音+词性）整理的人教版高中英语必修一的部分词汇示例：一、Unit 1。
1. exchange.- 发音：[ɪksˈtʃeɪndʒ]- 词性：动词/名词。
- 例句：We exchanged phone numbers.（动词）；They made an exchange of goods.（名词）2. lecture.- 发音：[ˈlektʃə(r)]- 词性：名词/动词。
- 例句：I attended a very interesting lecture yesterday.（名词）；He lectured us on history.（动词）3. registration.- 发音：[ˌredʒɪˈstreɪʃn]- 词性：名词。
- 例句：The registration for the course is still open.4. sex.- 发音：[seks]- 词性：名词。
- 例句：The sex of the baby is not known yet.5. female.- 发音：[ˈfiːmeɪl]- 词性：形容词/名词。
- 例句：There are more female students in this class.（形容词）；The female of the species is usually smaller.（名词）二、Unit 2。
1. puzzled.- 发音：[ˈpʌzld]- 词性：形容词。
- 例句：He had a puzzled look on his face.2. fluent.- 发音：[ˈfluːənt]- 词性：形容词。
- 例句：She is fluent in French.3. gradual.- 发音：[ˈɡrædʒuəl]- 词性：形容词。
文章题目：深度探讨雅思口语中的“concentration”在雅思口语考试中，理解和运用单词"concentration" 是非常重要的。
一般来说，在雅思口语考试中，考官可能会问你与"concentration" 有关的问题，比如有关学习、工作或者日常生活。
在这篇文章中，我们将深入探讨"concentration" 这一主题，分析其含义、重要性以及如何在口语表达中运用。
我们将从浅到深，由简入繁地为你解读这一主题。
一、"concentration" 的含义我们来了解一下"concentration" 这一词的含义。
在日常生活中，我们通常把"concentration" 理解为专注或者集中精力。
在学习或工作中，我们需要有足够的"concentration" 才能完成任务或学习。
"concentration" 还可以指化学物质的浓度，比如溶液中溶质的含量。
"concentration" 是一个非常灵活的词汇，我们需要在不同语境中灵活运用。
二、"concentration" 在雅思口语中的重要性在雅思口语考试中，考生在表达时需要有清晰的逻辑和表达流畅度。
而这就离不开对"concentration" 的理解和运用。
考生需要在口语表达时保持良好的"concentration"，以保证表达的准确性和连贯性。
"concentration" 还与思维的深度和广度有关，考生需要在回答问题时保持高度"concentration"，避免答非所问或者内容表面化。
"concentration" 在雅思口语中的重要性不言而喻。
三、如何提高口语表达中的"concentration"如何提高口语表达中的"concentration" 呢？我们可以通过平时的练习来提高口语表达中的"concentration"。
雅思concentration话题雅思口语中的concentration话题可以包括以下几个方面：1. 专注力的重要性：- Why is concentration important in daily life and study?- How can concentration help improve productivity?- What are the benefits of being able to concentrate well?2. 分心的原因和解决方法：- What are some common distractions that can affect concentration? - How do electronic devices affect people's ability to concentrate? - What strategies can people use to minimize distractions and improve concentration?3. 儿童与专注力：- Why do some children have difficulty concentrating in school?- What role do parents and teachers play in helping children develop concentration skills?- What activities or exercises can parents or teachers do to help children improve their focus?4. 科技和专注力：- How does technology affect people's ability to concentrate?- Can technology be used to improve concentration and focus?- Are there any apps or tools that can help people enhance their concentration skills?5. 专注力与工作：- How important is concentration in the workplace?- What strategies can employees use to stay focused and avoid distractions in a busy work environment?- How can employers create a conducive work environment that promotes concentration?需要注意的是，在回答这些问题时，可以结合个人经验、观点或专业知识进行回答，同时保持语言流畅、简洁明了，尽量用准确的词汇和语法表达自己的观点。
雅思 Concentration 话题简介集中注意力是人类认知能力中的重要组成部分，也是雅思口语和写作考试中常见的话题。
在现代社会，人们面临着越来越多的干扰因素，如手机、社交媒体和工作压力等，这些因素都会影响我们的注意力。
本文将探讨集中注意力的重要性、影响集中注意力的因素以及提高集中注意力的方法。
集中注意力的重要性集中注意力是人们进行学习、工作和生活所必需的基本能力。
无论是在学校还是在职场，只有保持良好的注意力才能更好地完成任务，并取得优异的成绩。
此外，集中注意力还可以提高记忆力和创造力，帮助我们更好地解决问题和应对挑战。
影响集中注意力的因素1. 外部干扰外部环境中存在许多干扰因素，如噪音、光线和温度等。
这些干扰会分散我们的注意力，使我们难以专注于当前任务。
例如，在学习时，如果周围有嘈杂的声音或明亮刺眼的灯光，我们就很难集中精力。
2. 内部干扰内部干扰是指来自我们自身的因素，如焦虑、压力和疲劳等。
这些因素会导致我们的思维不集中，影响我们的工作效率。
例如，在考试前感到紧张和担忧会分散我们的注意力，使我们难以专注于考试内容。
3. 技术干扰现代科技发展迅猛，手机、电脑和社交媒体成为了人们生活中不可或缺的一部分。
然而，过度使用这些科技产品会对注意力产生负面影响。
社交媒体上无尽的信息刺激和通知会分散我们的注意力，使我们难以集中精力完成任务。
提高集中注意力的方法1. 创造良好学习/工作环境为了提高集中注意力，创造一个安静、整洁且舒适的学习或工作环境是必要的。
选择一个没有干扰因素的地方，并确保充足的光线和适宜的温度。
此外，可以使用耳塞或白噪音等方法来减少外部噪音对注意力的干扰。
2. 制定合理的时间管理计划合理的时间管理可以帮助我们更好地分配精力和注意力。
制定一个详细的计划，将任务分解为小块，并设置合理的时间限制来完成每个任务。
遵循这个计划，每次专注于一件事情，避免同时处理多个任务，以提高效率和集中注意力。
3. 远离干扰因素在学习或工作期间，尽量远离干扰因素。
雅思concentration话题
（原创版）
目录
1.雅思口语话题题库 Concentration 题目的内容
2.题目的具体问题
3.人们在何时需要集中注意力
4.人们在何时最能集中注意力
5.集中注意力是否困难
正文
在雅思口语话题题库中，Concentration 题目是一个重要的话题。
以下是一些具体的问题：
1.是否重要集中注意力在你需要处理的事情上？
2.人们在何时需要集中注意力？
3.人们在何时最能集中注意力？
4.集中注意力是否困难？
对于这些问题，人们的回答可能因个人经历和情况而异。
然而，有一些普遍的观点和情况。
首先，对于第一个问题，大多数人可能会认为集中注意力是很重要的。
因为当我们集中注意力时，我们可以更好地理解和处理信息，从而更有效地完成任务。
其次，人们需要在许多情况下集中注意力，例如在学习、工作、驾驶等情况下。
在这些情况下，集中注意力可以帮助人们更好地完成任务，避免错误和危险。
然后，人们最能集中注意力的情况可能因人而异。
有些人可能在安静
的环境中最能集中注意力，而有些人可能在嘈杂的环境中更能集中注意力。
此外，有些人可能在早上最能集中注意力，而有些人可能在晚上更能集中注意力。
最后，对于集中注意力是否困难这个问题，有些人可能会认为很困难，因为有许多因素可能干扰我们的注意力，例如噪音、情绪、健康状况等。
然而，有些人可能认为集中注意力并不困难，因为他们可能有一些技巧和策略来帮助他们保持注意力。
总之，Concentration 题目是一个值得探讨的话题，因为它涉及到我们在日常生活中经常需要面对的问题。
雅思concentration话题【实用版】目录1.雅思口语话题题库 Concentration 题目概述2.Concentration 题目的四个问题3.如何提高注意力和专注力4.注意力和专注力对学习和工作的重要性正文一、雅思口语话题题库 Concentration 题目概述Concentration 题目是雅思口语话题题库中的一个重要部分，主要涉及到注意力和专注力方面的问题。
在考试中，考生需要针对题目中的问题进行回答和阐述，以展示自己的语言表达能力和思维能力。
本文将对Concentration 题目进行详细的分析和解答，帮助考生更好地应对这一类型的题目。
二、Concentration 题目的四个问题1.是否重要集中精力处理一件事情？2.人们何时需要集中精力？3.人们何时最为专注？4.保持专注是否容易？这三个问题都围绕着注意力和专注力这一主题展开，旨在考查考生对这一主题的理解和看法。
下面我们将针对每个问题进行具体的分析和解答。
三、如何提高注意力和专注力1.设定明确的目标：在开始工作或学习之前，设定一个明确的目标可以帮助我们集中注意力，提高工作效率。
2.保持良好的作息规律：保持良好的作息规律，保证充足的睡眠，可以帮助我们维持良好的精神状态，提高注意力。
3.减少干扰：在工作或学习过程中，尽量减少外部干扰，如关闭手机、电视等，可以帮助我们保持专注。
4.合理安排时间：合理安排时间，适时休息，可以避免长时间的工作或学习导致的疲劳，有利于注意力的保持。
5.培养兴趣：对工作和学习内容保持兴趣，可以提高我们的专注力。
四、注意力和专注力对学习和工作的重要性注意力和专注力对学习和工作具有重要意义。
保持专注可以帮助我们更好地理解和掌握知识，提高学习效率。
同时，注意力和专注力也是工作效率的重要保证。
在高度竞争的社会中，提高注意力和专注力可以帮助我们更好地应对挑战，实现个人价值。
总之，雅思口语话题题库 Concentration 题目是考生在备考过程中需要重点关注的内容。
This question appeared on the 2009 paper. The answer below was written by an English student in that exam. Marks were high.Using an industry of your choice to illustrate, critically assess alternative measures of industry concentration.Industry concentration refers to the extent to which the output for a given single industry is located in a small number of firms (Clark 1985). Measures of concentration relate to the number of firms in an industry and the distribution of market shares between them.In this essay I will detail alternative absolute measures of concentration and inequality measures of industry concentration and assess their usefulness using Hannah and Ka ys’ criteria (1977). Firstly I will discuss the criteria which has been advanced by Hannah and Kay (1977) as a basis for discussing the usefulness of concentration measures. Secondly I will discuss absolute measures of concentration including concentration ratios and Herfindahl-Hirschman (HH) index. Absolute measures take into account the absolute number of firms and their relative distribution among the industry. Thirdly I will discuss inequality measures such as the Gini coefficient and the coefficient of variation ratio. These measures do not take account of the absolute number of firms in the industry and therefore fail to meet Hannah and Ka y’s merger condition and entry condition s. I will use the chocolate industry as an illustration of these measures.As Clark (1985) argued, concentration measures should be easy to calculate, not dependant on industry size, and should perhaps lie between 0 and 1 as to facilitate comparison between individual industries. Hannah and Kay’s properties of industry concentration (1977) provide a more useful platform for discussion regarding the usefulness of concentration measures. Hannah and Kay firstly highlighted the concentration curves as a useful tool to assess concentration. The concentration curve plots the cumulative market shares of firms in the industry against number of firms:The concentration curve pictured above shows the cumulative number of market shares, cumulated from the largest firm. The higher the curve, the higher is industry concentration. As can be seen, the chocolate industry is dominated by three large firms (Cadbury, Nestle, Mars) and is a highly concentrated industry. Concentration curves can be plotted over time to see how concentration is changing. Over the last six years, concentration has remained largely similar in this industry.Indices are often used as summary measures of concentration curves and Hannah andKay developed four properties of an ideal index:1. Concentration curve ranking criterion: for one industry to be considered more concentrated than another, its concentration curve must be above the other’s everyw here on the graph. If they cross, then the situation is ambiguous and no judgement can be made.2. Sales Transfer Principle: the transfer of sales from a small firm to a large firm must increase concentration.3. Entry Condition: the entry of a small firm into an industry must decrease concentration.4. Merger Condition: if two firms merge then concentration must be seen to have increased.As Clark (1985) noted, although some academics may prefer to adopt different criteria, the Hannah-Kay properties form a solid basis for discussing the validity of concentration measurements.Perhaps the simplest measure of industry concentration as noted by Clark (1985) wouldbe the inverse of the number of firms in the industry; that is C=1/m where m is the number of firms in the industry. As the number of firms decrease, concentration increases.However this measure does not take account of the relative distributions of market shares,and therefore provides a misleading indication of concentration. For instance, in relation to the UK chocolate industry, there is a wide number of own label brands that make up around 7% of the market and using this inverse measure would give too much weight to these small brands and not enough to the concentration of output in the three largest firms. This measure therefore does not meet Hannah-Kay sales transfer criterion, and is therefore limited in validity.The most popular absolute measure of concentration is the concentration ratio (CR). This essentially is the sum of market shar es of the largest ‘n’ firms. That is :∑==n1i i n S CRwhere S i = the share of the i th firm ie Qq S i i =and q i is the output of the i th firm, divided by the output of the entire industry, Q. This ratio is easy to calculate and is intuitively easy to grasp. However the selection of ‘n’ is arbitrary. This ratio therefore only measures one point of the concentration curve. It may therefore not meet Hannah-Kay criteria of the effect of mergers and sale transfers if the top ‘n’ firms ar e not included.The concentration ratios for the chocolate industries top 5 firms areCR 1 = 35.5%CR 2 = 65.5%CR 3 = 80%CR 4 = 84.4%CR 5 = 85%For the chocolate industry therefore CR 3 may be the most useful as it indicates the high level of concentration in the top three firms. As has been highlighted, this measure may therefore only be valid in certain instances, as it may obscure some effects that have been highlighted by Hannah and Kay as necessarily effecting concentration.Another measure of concentration is the Herfindahl-Hirschman (HH) index. This measure is the sum of the squared market shares of the industry:()∑==m1i 2i S HHwhere m is the total number of firms in the industry. This measure therefore gives greater weight to the larger firms and takes into account the relative sizes and number of market shares and firms in the industry. This measure therefore satisfies all of Hannah-Kay properties.There is consensus that a HH-index between 0 and 0.1 represents a low concentration, 0.1<HH< 0.18 represents a moderate concentration, and HH>0.18 represents a highly concentrated industry. The HH-index for the chocolate industry is 0.241. This correctly highlights the fact that the industry is highly concentrated, with much market share belonging to the three largest firms. The H-index seems to be a useful measure of concentration that highlights the relative inequality of shares.Hannah and Kay extended the HH index and added their own measure;()∑=α=m1i i S HK where α>0. The authors essentially highlighted the option of increasing the weight given to larger firms if necessary. This may be applicable in highly concentrated industries. This satisfies all of the Hannah-Kay properties also.Measures such as the Gini coefficient and coefficient of variation are also used as measures of industry concentration. A Lorenz curve plotting the cumulative market shares against the smallest to largest firms as a percentage, is a useful indicator of inequality:The straighter the curve, the more equally distributed are the market shares of the firms in the industry. A Gini coefficient may be used as an indicator of inequality. This essentially calculates the area under the curve, as marked by the inequality of market shares, to the total was under the curve. That is ODAArea OKA Area G =. However as this does not take into account the absolute number of firms in the industry, this measure may not meet Hannah and Kay ’s merger and firm entry conditions. As a result, such a measure may be of limited value.Another inequality measure is the coefficient of variation. This calculates the mean distance of firm shares to the main firm shares relative to the mean firm size. Mathematically , the coefficient of variation is:qCOV σ=where t he standard deviation σ measures the dispersion around the mean: ()m q q m 1i 2i ∑=-=σ and the mean firm size (measured by output) = sum of firm sizes ÷ the total number of firms in the industry (m):m q q m 1i i∑==A high coefficient of variation indicates high variation in firm size, which indicates low concentration and vice versa. However, again this does not take into account the absolute number or firms in an industry.As highlighted, absolute measures of industry concentration take into account number of firms and inequality of market shares, but inequality measures do not take into account number of firms. As a result, absolute measures such as HH-index which meet Hannah and Kay’s conce ntration measurement criteria may be more useful concentration indicators. One must take into account the industry’s structure when selecting each measure. Highly concentrated industries such as the chocolate industry may not be reflected accurately in some measures such as the inverse measure of concentration.。
Concentration(See also procrastination and workblock and coping with exams leaflets.)We all have the ability to concentrate someof the time. At other times our thoughts are scattered and our minds race from one thingto another. This is often when we feel bored, anxious or when we daydream. To deal with these times, we need to learn and to practice concentration skills. This may take some time and our level of success is likely to depend on our enthusiasm for the task, our skill at doing it, our emotional and physical state and our environment. In learning concentration skills, we aim to extend our concentration span – the time we are able to focus on a specific task before our thoughts wander. We will have a different span for different tasks, so whilst most people find their average level is close to an hour, some will find that with some tasks it will just be a few minutes and others will find that it could be two or three hours. ChecklistTo improve your concentration span, you may want to consider the following:•I f you are stuck with a particular task, checkif the problem is one of poor concentration rather than lack of the necessary knowledge or understanding.•E nsure that your environment aids concentration - reduce distractions and don’t be so comfortable that you nod off.•G et to know the times of day when you areat your most mentally and physically fresh. Do tasks that need most concentration at these times.•I n between periods of concentration, do things to change your physical and mental activity - move around to boost your circulation if you have been sitting, give your brain a new focus. •G ive yourself incentives and rewards appropriate to the level of concentration you have had to maintain.•B e active in your mental activity. Formulate questions to help you focus when reading reference material or listening to a lecture and then write brief notes.•E xperiment and see whether working with another person helps you keep focused on the task.•A void excessive use of caffeine, it may increase your alertness in the short term but possible side-effects include sleeplesness and anxiety./wellbeing 2ConcentrationThree Basic StrategiesThe following three strategies are basic to concentration:1. Stop!When you notice your thoughts wandering,say to yourself STOP and then gently bring your attention back to where you want it to be. Each time it wanders bring it back. To begin with, this could be several times a minute, but each time, say STOP and then re-focus. Don’t waste energy trying to keep thoughts out of your mind. Just put the effort into STOP and re-focus. Over time, you will most likely find that the period of time between your straying thoughts starts to expand.2. AttendThis is about maintaining concentration and not giving in to distractions. It could be describedas a sort of tunnel vision or as being focused. The idea is to keep your concentration on what is physically in front of you. For example, in a lecture or presentation, if others move or cough, don’t look at them. Actively exclude them from the link or tunnel formed between you andthe lecturer. If you are distracted, use the STOP technique to regain concentration. 3. Create worry timeSet aside one or more specific periods in the day when you allow yourself to worry. It can help to set them just before something that you havea specific time to do – tuning into a favouriteTV programme or having a meal. Whenever an anxiety or distracting thought enters your mind during the day, banish it until your next worry time, and re-focus on what you are supposedto be doing. Some people find it helpful to write down the banished thought first. You may notice, particularly if you keep a list, that certain things keep reappearing.If your concerned about these you might want to explore speaking to a counsellor./wellbeing3/wellbeing4 ConcentrationSpecific Problems1. Day-dreamingUse the STOP technique and Attending tocounteract it. You may choose to daydream after a period of concentration as a reward.2. Anxiety or Negative thinkingLoss of concentration can lead to negative thoughts about yourself. Deal with them as with other distractions, and banish them into your Worry Time, when you can check out their reality. See STRESS AND ANXIETY leaflet for Challenging Negative Thoughts.3. Concentrating on a topic which bores you. Actively search in the material for aspects of the subject that can be turned into useful and possibly even interesting information. You may want to focus on finding say five central themes or to use mind-maps or spider diagrams, to write test questions to summarise your learning after each study session.Example: mind mapFocus on the personal rewards of completing the topic satisfactorily, even if it’s just to be rid of it. And build in treats to reward yourself as you progress through the task. If all else fails, see it as a personal challenge.4. Feeling saturated after concentrating well Take a short break and then recharge your mental batteries by reviewing what you have done so far, considering whether it might help to switch to a new topic now. If you feel too tired to restart after a short break, review what you have done and define where you need to pick it up again. You may want to make a note of this. Then before you stop, decide when you will restart the task.Centre for Wellbeing9am to 5pm, Monday to Friday Telephone: 01483 689498 (extension 9498)E-mail:****************************.ukenvironment。
a rXiv:081.436v1[mat h.PR]25J an28On the infimum convolution inequality ∗†‡ta l a and J.O.Wojtaszczyk Abstract In the paper we study the infimum convolution inequalites.Such an inequality was first introduced by B.Maurey to give the optimal concen-tration of measure behaviour for the product exponential measure.We show how IC inequalities are tied to concentration and study the optimal cost functions for an arbitrary probability measure µ.In particular,we show the optimal IC inequality for product log–concave measures and for uniform measures on the ℓn p balls.Such an optimal inequality implies,for a given measure,in particular the Central Limit Theorem of Klartag and the tail estimates of Paouris.1Introduction and Notation In the seminal paper [16],B.Maurey introduced the so called property (τ)for a probability measure µwith a cost function ϕ(see Definition 2.1below)and established a very elegant and simple proof of Talagrand’s two level concentra-tion for the product exponential distribution νn using (τ)for this distribution and an appropriate cost function w .It is natural to ask what other pairs (µ,ϕ)have property (τ)?As any µsatisfies (τ)with ϕ≡0,one will rather ask how big a cost function can one take.In this paper we study the probability measures µthat have property (τ)with respect to the largest (up to a multiplicative factor)possible convex cost function Λ⋆µ.This bound comes from checking property (τ)for linear functions.We say a measure satisfies the infimum convolution inequality (IC for short)if the pair (µ,Λ⋆µ)satisfies τ.It turns out that such an optimal infimum convolution inequality has very strong consequences.It gives the best possible concentration behaviour,gov-erned by the so–called L p -centroid bodies (Corollary 3.10).This,in turn,implies in particular a weak–strong moment comparison (Proposition 3.12),the Central Limit Theorem of Klartag [12]and the tail estimates estimates of Paouris [18](Proposition 3.15).We believe that IC holds for any log–concave probability measure,which is the main motivation for this paper.Maurey’s inequality for the exponential measure is of this optimal type.We transport this to any log–concave measure on the real line,and as the inequal-ity tensorizes,any product log–concave measure satisfies IC(Corollary2.19). However,the main challenge is to provide non–product examples of measures satisfying IC.We show how such an optimal result can be obtained from con-centration inequalites,and follow on to prove IC for the uniform measure on anyℓn p ball for p≥1(Theorem5.30).With the techniques developed we also prove a few other results.We give a proof of the log–Sobolev inequality forℓn p balls,where p≥2(Theorem5.31) and provide a new concentration inequality for the exponential measure for sets lying far away from the origin(Theorem4.6).Organization of the paper.This section,apart from the above intro-duction,defines the notation used throughout the paper.The second section is devoted to studying the general properties of the inequality IC.In subsection 2.1we recall the definition of property(τ)and its ties to concentration from [16].In subsection2.2we study the opposite implication—what additional as-sumptions one needs to infer(τ)from concentration inequalities.In subsection 2.3we show thatΛ⋆µis indeed the largest possible cost function and define the inequality IC.In subsection2.4we show that product log–concave measures satisfy IC.In the third section we give more attention to the concentration inequalities tied to IC.In subsection3.1we show the connection to Z p bodies.In subsection 3.2we continue in this vein with the additional assumption our measure isα–regular.In subsection3.3we show how IC implies a comparison of weak and strong moments and the results of[12]and[18].In the fourth section we give a modification of the two–level concentration for the exponential measure,in which for sets lying far away from the origin only an enlargement by tB n1is used.This will be used in thefifth section,which focuses on the uniform measure on the B n p ball.In subsection5.1we define and study two rather standard transports of measure used further on.In subsection 5.2we use these transports along with the concentration from section4and a Cheeger inequality from[19]to give a proof of IC for p≤2.In section5.3we show a proof of IC for p≥2and a proof of the log–Sobolev inequality for p≥2.We conclude with a few possible extensions of the results of the paper in the sixth section.Notation.By ·,· we denote the standard scalar product on R n.For x∈R n we put x p=( n i=1|x i|p)1/p for1≤p<∞and x ∞=max i|x i|,we also use|x|for x 2.We set B n p for a unit ball in l n p,i.e..B n p={x∈R n: x p≤1}.Byνwe denote the symmetric exponential distribution on R,i.e.the prob-ability measure with the density1the uniform distribution on B n p.The letters c,C denote absolute numerical constants,which may change fromline to line.By c(p),C(p)we mean constants dependent on p(or,formally,a family of absolute constants indexed by p),these also may change from line to line.Other letters,in particular greek letters,denote constantsfixed for agiven proof or section.For any sets of positive real numbers a i and b i,i∈I, by a i∼b i we mean there exist absolute numerical constants c,C>0such that ca i<b i<Ca i for any i∈I.Similarly for collections of sets A i and B i by A i∼B i we mean cA i⊂B i⊂CA i for any i∈I,where again c,C>0are absolute numerical constants.By∼p we mean the constants above can dependon p.2Infimum convolution inequality2.1Property(τ)Definition2.1.Letµbe a probability measure on R n andϕ:R n→[0,∞]be a measurable function.We say that the pair(µ,ϕ)has property(τ)if for any bounded measurable function f:R n→R,R n e f2ϕdµ R n e−f dµ≤1,(1) where for two functions f and g on R n,f2g(x):=inf{f(x−y)+g(y):y∈R n}denotes the infimum convolution of f and g.The following two easy observations are almost immediate(c.f.[16]): Proposition2.2(Tensorization).If pairs(µi,ϕi),i=1,...,k have property (τ)andϕ(x1,...,x k)=ϕ1(x1)+...+ϕk(x k),then the couple(⊗k i=1µi,ϕ)also has property(τ).Proposition2.3(Transport of measure).Suppose that(µ,ϕ)has property(τ) and T:R n→R m is such thatψ(T x−T y)≤ϕ(x−y)for all x,y∈R n.Then the pair(µ◦T−1,ψ)has property(τ).Maurey noticed that property(τ)impliesµ(A+Bϕ(t))≥1−µ(A)−1e−t, whereBϕ(t):={x∈R n:ϕ(x)≤t}.We will need a slight modification of this estimate.3Proposition2.4.Property(τ)for(ϕ,µ)implies for any Borel set A and t≥0,µ(A+Bϕ(t))≥e tµ(A)2(e t/2+e−t/2)<e t/2,hence f t(p)>min(e t/2p,1/2)and(3)follows.Moreover for p≥1/21−f t(p)=1−p(e t+1)/2<e−t/2(1−p)and we get(4).Let F(x)=ν(−∞,x]and g t(p)=F(F−1(p)+t).Previous calculations show that for t,p>0,f t(p)≥g t/2(p)if F−1(p)+t/2≤0or F−1(p)≥0.Since g t+s=g t◦g s and f t+s=f t◦f s,we get that f t(p)≥g t/2(p)for all t,p>0, hence(2)implies(5).The main theorem of[16]states thatνsatisfies(τ)with a sufficiently chosen cost function.Theorem2.5.Let w(x)=19(|x|−2)otherwise.Then the pair(νn, n i=1w(x i))has property(τ).4Theorem2.5together with Proposition2.4immediately gives the following two-level concentration:νn(A)=ν(−∞,x]⇒∀t≥0νn(A+6√t}].(7)Then the pair(µ,1β))has property(τ).In particular ifϕis convex,sym-metric andϕ(0)=0then(7)implies property(τ)for(µ,ϕ(·36ϕ(·36ϕ ·36ϕ ·By the definition of w it easily follows that x2≤max{6√β)/36(s2)⊂A f21β ,s1+s2 ,we obtain the property(8).The last part of the statement immediately follows since any symmetric convex functionϕis radius-wise nondecreasing and if additionallyϕ(0)=0, thenϕ(x/36)≤ϕ(x)/36for any x.The next proposition shows that inequalities(3)and(4)are strongly related. Proposition2.7.The following two conditions are equivalent for any Borel set K andγ>1,∀A∈B(R n)µ(A)>0⇒µ(A+K)>min γµ(A),12⇒1−µ(˜A−K)<1γµ(A+K)=1Finally,if x≤0≤x+t,we getµ(A+K)≥1/2=ν(−∞,0],hence by the previous case,µ(A+2K)=µ((A+K)+K)>ν(−∞,t]≥ν(−∞,x+t].Corollary2.8shows that if the cost functionϕis symmetric and convex, condition(7)(with2βinstead ofβ)for t≥1is implied by the following:∀A∈B(R n)µ(A)>0⇒µ(A+βBϕ(t))>min{e tµ(A),1/2}.(11) To treat the case t≤1we will need Cheeger’s version of the Poincar´e inequality.We say that a probability measureµon R n satisfies Cheeger’s inequality with constantκif for any Borel set Aµ(A+tB n2)−µ(A)µ+(A):=lim inft→0+tB n2for all t<1,hence Cheeger’s inequality implies that condition(7)holds for t<1with C=αδ.Therefore(7)holds for all t≥0with C=min{2γ,αδ}and the assertion follows by Corollary2.6.2.3Optimal cost functionsA natural question arises:what other pairs(µ,ϕ)have property(τ)?First we have to choose the right cost function.To do this let us recall the following definitions.Definition2.10.Let f:R n→(−∞,∞].The Legendre transform of f,denoted L f is defined by L f(x):=sup y∈R n{ x,y −f(y)}.The Legendre transform of any function is a convex function.If f is convex and lower semi-continuous,then LL f=f,and otherwise LL f≤f.In general, if f≥g,then L f≤L g.The Legendre transform satisfies L(Cf)(x)=C L f(x/ C)and if g(x)=f(x/C),then L g(x)=L f(Cx).For this and other properties of L,cf.[15].The Legendre transform has been previously used in the context of convex geometry,see for instance[2]and[13].7Definition 2.11.Let µbe a probability measure on R n.We define M µ(v ):= R ne v,x dµ(x ),Λµ(v ):=log M µ(v )andΛ⋆µ(v ):=L Λµ(v )=supu ∈R nv,u −ln R n e u,x dµ(x ) .The function Λ⋆µplays a crucial role in the theory of large deviations cf.[9].Remark 2.12.Let µbe a symmetric probability measure on R n and let ϕbe a convex cost function such that (µ,ϕ)has property (τ).Thenϕ(v )≤2Λ⋆µ(v/2)≤Λ⋆µ(v ).Proof.Take f (x )= x,v .Thenf 2ϕ(x )=inf y (f (x −y )+ϕ(y ))=inf y ( x −y,v +ϕ(y ))= x,v −L ϕ(v ).Property (τ)yields1≥e f 2ϕdµ e −f dµ=e −L ϕ(v ) e x,v dµ e − x,v dµ=e −L ϕ(v )M 2µ(v ),where the last equality uses the fact that µis symmetric.Thus by taking the logarithm we get L ϕ(v )≥2Λµ(v ),and by applying the Legendre transform we obtain ϕ(v )=LL ϕ(v )≤2Λ⋆µ(v/2).The inequality 2Λ⋆µ(v/2)≤Λ⋆µ(v )followsby the convexity of Λ⋆µ.The above remark motivates the following definition.Definition 2.13.We say that a symmetric probability measure µsatisfies the infimum convolution inequality with constant β(IC(β)in short),if the pair (µ,Λ∗µ(·Proof.If we put V ={(v 0,˜v ):v 0=−Λµ(β˜v )},then the right-hand side is equal to 1and ψV (x )=Λ⋆µ(x/β),so if µsatisfies (13)for this V ,it satisfies IC(β).On the other hand,suppose µsatisfies IC(β).Take an arbitrary nonempty set V .If the right-hand side supremum is infinite,the inequality is obvious,so we may assume it is equal to some s <∞.This means that for any (v 0,˜v )∈V we have v 0+Λµ(β˜v )≤log s ,that is v 0≤log s −Λµ(β˜v ).ThusψV (x )=sup v ∈V {v 0+ x,˜v }≤log s +sup v ∈V{ x,˜v −Λµ(β˜v )}≤log s +sup ˜v ∈R n{ x,˜v −Λµ(β˜v )}=log s +Λ⋆µ(x/β),which in turn means from IC(β)that the left hand side is no larger than s .Proposition 2.16.Let L :R n →R k be a linear map and suppose that a prob-ability measure µon R n satisfies IC(β).Then the probability measure µ◦L −1satisfies IC(β).Proof.For any set V ⊂R ×R k and any function f :R k →R put ¯f (x ):=f (L (x ))and ¯V :={(v 0,L ⋆(˜v )):(v 0,˜v )∈V },where L ⋆is the Hermitian conjugate of L .Then direct calculation shows ψV (L (x ))=ψ¯V (x )and f 2ψV (L (x ))≤¯f 2ψ¯V (x ),thus R k e f 2ψV d (µ◦L −1)≤R ne ¯f 2ψ¯V dµandR k e−f d (µ◦L −1)=R n e −¯f dµand finally sup v ∈Ve v 0 R k e β x,˜v d (µ◦L −1) =sup v ∈¯V e v 0 R ne β x,˜v dµ ,which substituted into (13)gives the thesis.Proposition 2.17.For any x ∈R ,11+x 2−1−ln √2.Since a/2≤a −ln(1+a/2)≤a for a ≥0,we get 11+x 2−1)≤Λ⋆ν(x )≤√1+x 2−1=x 21+x 2+1≥12+1min(|x |,x 2).The last statement follows by Theorem 2.5,since min((x/9)2,|x |/9)≤w (x ).92.4Logaritmically concave product measuresA measureµon R n is logarithmically concave(log–concave for short)if for all nonempty compact sets A,B and t∈[0,1],µ(tA+(1−t)B)≥µ(A)tµ(B)1−t.By Borell’s theorem[7]a measureµon R n with a full–dimensional support is logarithmically concave if and only if it is absolutely continuous with respect to the Lebesgue measure and has a logarithmically concave density,i.e.dµ(x)= e h(x)dx for some concave function h:R n→[−∞,∞).Note that ifµis a probabilistic,symmetric and log–concave measure on R n, then bothΛµandΛ⋆µare convex and symmetric,andΛµ(0)=Λ⋆µ(0)=0.Recall also that a probability measureµon R n is called isotropic if u,x dµ(x)=0and u,x 2dµ(x)=|u|2for all u∈R n.It is easy to check that for any measureµwith a full–dimensional support there exists a linear map L such thatµ◦L−1is isotropic.The next theorem(with a different universal,but rather large constant)may be deduced from the results of Gozlan[10].We give the following,relatively short proof for the sake of completeness.Theorem2.18.Any symmetric log-concave measure on R satisfies IC(48). Proof.Letµbe a symmetric log–concave probability measure on R,we may assumeµis isotropic by Proposition2.16.Denote the density ofµby g(x)and let the tail function beµ[x,∞)=e−h(x).Leta:=inf{x>0:g(x)≤e−1g(0)},then g(x)≤e−x/a g(0)for x>a and g(x)≥e−x/a g(0)for x∈[0,a).Therefore ∞0g(x)dx≤ag(0)+ ∞a g(0)e−x/a dx,that is1/2≤ag(0)(1+e−1).(14) We also have a0x2g(0)e−x/a dx≤ ∞0x2g(x)dx,soa3g(0)(2−5e−1)≤1/2.(15) From(14)and(15)we get in particular1e2(2e−5)Let T:R→R be a function such thatν(−∞,x)=µ(−∞,T x).Thenµ=ν◦T−1,T is odd and concave on[0,∞).In particular,|T x−T y|≤2|T(x−y)| for all x,y∈R.Notice that T′(0)=1/(2g(0))≤4,thus by concavity of T,T x≤4x for x≥0.Moreover for x≥0,h(T x)=x+ln2.Define˜h(x):= x2for|x|≤2/3max{4/9,h(x)}for|x|>2/3.We claim that(µ,˜h(·24 ≤w(x)for x≥0,(16) where w(x)is as in Theorem2.5.We have two cases.i)T x≤16,then˜h T x24 2≤min 46 2 ≤w(x).ii)T x≥16,then x≥4and˜h T x9,h T x9,h(T x)9,x+ln29≤w(x).So(16)holds in both cases.To conclude we need to show thatΛ∗µ(x)≤˜h(x).For|x|≤2/3it follows from the more general Proposition3.3below.Notice that for any t,x≥0,Λµ(t)≥tx+lnµ[x,∞)=tx−h(x),henceΛ∗µ(x)=Λ∗µ(|x|)=supt≥0 t|x|−Λµ(t) ≤h(|x|)≤˜h(x)for|x|>2/3.Using Corollary2.14we getCorollary2.19.Any symmetric,log–concave product probability measure on R n satisfies IC(48).We expect that in fact a more general fact holds.Conjecture1.Any symmetric log–concave probability measure satisfies IC(C) with a uniform constant C.113Concentration inequalities.3.1L p-centroid bodies and related setsDefinition3.1.Letµbe a probability measure on R n,for p≥1we define the following setsM p(µ):= v∈R n: | v,x |p dµ(x)≤1 ,Z p(µ):=(M p(µ))◦= x∈R n: v,x p≤ v,y p dµ(y)for all v∈R n and for p>0we putB p(µ):={v∈R n:Λ∗µ(v)≤p}.Sets Z p(µK)for p≥1,whenµK is the uniform disribution on the convex body K are called L p-centroid bodies of K,their properties were investigated in[18].Proposition3.2.For any symmetric probability measureµon R n and p≥1,Z p(µ)⊂21/p eB p(µ).Proof.Let us take v∈Z p(µ),we need to show thatΛ⋆µ(v/(21/p e))≤p,that isu,v21/p e−Λµ(u)≤ββ,v ≤p·1.ii)β>21/p ep.We havee u,x dµ(x)≥ e u,x /p p I{ u,x ≥0}dµ(x)≥ u,x2 u,x2 21/p e u,x21/p epΛµ(21/p epu/β)≥β21/p e−Λµ(u)≤ββ,v −βProposition 3.3.If µis a symmetric,isotropic probability measure on R n ,then min {1,Λ∗µ(u )}≤|u |2for all u ,in particular√(2k )!u,x2kdµ(x )≥1+∞ k =1|u |2k 2(1+|u |)ln(1+|u |)+(1−|u |)ln(1−|u |)≤|u |2,where to get the last inequality we used ln(1+x )≤x for x >−1.3.2α-regular measures.To establish inlusions opposite to those in the previous subsection,we introduce the following property:Definition 3.4.We say that a measure µon R n is α-regular if for any p ≥q ≥2and v ∈R n ,| v,x |pdµ(x )1/p ≤αp 2eα≤p.(17)Indeed if we fix u ∈M p (µ)and put ˜u :=pu2eα| u,x |k dµ(x ) 1/k ≤p 2ek >p.Hencee˜u ,xdµ(x )≤e| ˜u ,x |dµ(x )=∞ k =01k !p k !k 2eα+1≤e p13and(17)follows.Take any v /∈4eαZ p (µ),then we may find u ∈M p (µ)such that v,u >4eαand obtainΛ∗µ(v )≥ v,pu 2eα>p 2αe,|u |22p }B n2for all p >0.Proof.We have by the symmetry,isotropicity and regularity of µ,eu,xdµ(x )=∞k =012+∞ k =2(αk |u |)2k 2+∞ k =2αe |u |2+424≤1+α2e 2|u |2+(αe |u |)42αe ,|u |2qM p (µ)and Z p (µ)⊂αpq B q (µ)for all p ≥q >0.Proposition 3.8.Symmetric log–concave measures are 1-regular.Proof.If X is distributed according to a symmetric,log–concave measure µand u ∈R n ,then the random variable S = u,X has a log–concave symmetric distribution on the real line.We need to show that (E |S |p )1/p ≤p(Γ(q +1))1/q(E |S |q )1/q ,14so it is enough to show that the function f (x ):=12πx x +1/2e −x +µ(x ),where µ(x )=∞arctg(t/x )(e 2πt −1)−1dt is decreasing function.Thusln f (x )=µ(x )2x−1is indeed nonincreasing on [2,∞).Let us introduce the following notion:Definition 3.9.We say that a measure µsatifies the concentration inequality with constant β(CI(β)in short)if∀p ≥2∀A ∈B (R n )µ(A )≥1Proposition3.11.Letµbe a symmetric log-concave probability measure on R n and c∈(0,1].Thenµ A+402min{e pµ(A),1}for p≥cn orµ(A)≤e−cn.ing a standard volumetric estimate for any r>0we may choose S⊂M r(µ)with#S≤5n such that M r(µ)⊂ u∈S(u+12 ≤ u∈S 225n 2e−max{p,n}≥1−µ(A),2so A∩30c−1Z p(µ)=∅,hence0∈A+30c−1Z p(µ)andµ(A+40c−1Z p(µ))≥µ(10c−1Z p(µ))≥1/2.ii)q≥max{p,cn}.Let˜q:=max{q,n}˜A:=A∩30c−1Z q(µ),we have as in i),µ(30c−1Z q(µ))>1−e−˜q/2,thusµ(˜A)≥µ(A)/2.Moreover, 1−p q30c−1Z q(µ)⊂A+30c−1Z p(µ)andµ A+40c−1Z p(µ) ≥µ 1−p q10c−1Z q(µ)≥µ 1−p q10Z˜q(µ) ≥µ(˜A)1−p q≥ 1q 1q≥1q=1Proposition3.10shows that Conjecture1implies Conjecture2.Both hy-potheses would be equivalent provided that the following conjecture of Kannan, Lov´a sz and Simonovits holds.Conjecture3(Kannan–Lov´a sz–Simonovits[11]).There exists an absolute con-stant C such that any symmetric isotropic log–concave probability measure sat-isfies Cheeger’s inequality with constant1/C.3.3Comparison of weak and strong momentsProposition3.12.Suppose that a probability measureµon R n isα-regular and satisfies CI(β).Then for any norm · on R n and p≥2,x −Medµ( x ) p dµ 1/p≤2αβsup u ∗≤1 | u,x |p dµ 1/p, where · ∗denotes the norm dual to · .Proof.For p≥2we definem p:=sup u ∗≤1 | u,x |p dµ 1/p.Let M:=Medµ( x ),A:={x: x ≤M}and˜A:={x: x ≥M}.Then µ(A),µ(˜A)≥1/2so by CI(β)and Remark3.7,∀t≥p1−µ A+βαt2e−t,1−µ ˜A+βαt2e−t. Let y∈Z p,then there exists u∈R n with u ∗≤1such thaty = u,y ≤ | u,x |p dµ(x) 1/p≤m p,hence x ≤M+tm p for x∈A+t Z p(µ).Thus for t≥p,µ x: x ≥M+αβt p Z p(µ) ≤1pm p ≤e−t for t≥p.17Now integrating by parts,| x −M|p dµ 1/p≤αβm p p m p dt 1/p≤αβm pp ≤2αβm p.Remark3.13.Under the assumptions of Proposition3.12by the triangle in-equality we get forγ=4αβ,∀p≥q≥2 x − x q dµ 1/q p dµ 1/p≤γsup u ∗≤1 | u,x |p dµ 1/p.(19)This motivates the following definition.Definition3.14.We say that a probability measureµon R n has comparable weak and strong moments with the constantγ(CWSM(γ)in short)if(19)holds for any norm · on R n.Conjecture4.Every symmetric log–concave probability on R n measure satis-fies CWSM(C).Proposition3.15.Letµbe an isotropic,probability measure on R n satisfying CWSM(γ).Theni) | x 2−√n+γαn+sup u 2≤1 | u,x |p dµ 1/p≤√2pby theα-regularity and isotropicity ofµ.Remark3.16.Property i)plays the crucial role in the Klartag proof of the central limit theorem for convex bodies[12].Paouris[18]showed that moments of the Euclidean norm for symmetric isotropic log-concave measures are bounded by C(p+√We conclude this section with the estimate that shows comparison of weak and strong moments for any probability measure and p>n/C.Proposition3.17.For any p>0we havex −Medµ( x ) p dµ 1/p≤ x p dµ 1/p≤2·5n/p supu ∗≤1 | u,x |p dµ 1/p.Proof.As in the proof of Proposition3.11we canfind u1,...,u N with u i ∗≤1, N≤5n such that x ≤2max i≤N u i,x for all x.Thenx p dµ≤2p i≤N| u i,x |p dµ≤2p5n sup u ∗≤1 | u i,x |p dµ.Moreover{ x ≥M}( x −M)p dµ(x)≤ { x ≥M}( x p−M p)dµ(x)≤ x p dµ(x)−12M p.4Modified Talagrand concentration for expo-nential measureIn this section we show that for a set lying far from the origin Talagrand’s two level concentration for the exponential measure may be somewhat improved, namely(for sufficiently large t)it is enough to enlarge the set by tB n1instead of tB n1+√Now let us takes :=2|A 1|1/n r 1,ns +(1−s )−tss−t s=s −n |A 1|≥2n −t1−t2n −t|A 1|≥e t/2|A 1|.Notice that A 1+tB n1⊂{x :x 1≥u −t },so we obtain A +tB n 1)∩nB n 1∩ x :x 1≥u −t ≥e t/2 A ∩nB n 1∩ x :x 1≥u ,in the same way we showA +tB n 1 ∩nB n 1∩ x :x 1≤−u +t ≥e t/2 A ∩nB n 1∩ x :x 1≤−u .Remark 4.2.A similar result (although with a constant multiplicative factor)can be obtained using the same technique and more calculations for n 1/p B npinstead of nB n1for p ∈[1,2].Lemma 4.3.If u ≥t >0then for any i ∈{1,...,n }we haveνn A +tB n1∩ x :|x i |≥u −t ≥e t/2νn A ∩ x :|x i |≥u .Proof.Take an arbitrary k ∈N .Let P :R n +k →R n be the projection onto firstn coordinates.Let ρk be the uniform probability measure on (n +k )B n +k1,and ˜νk the measure defined by ˜νk (A )=ρk (P −1(A )).Take an arbitrary set A ⊂R n .Notice that for any set C ⊂R n we haveC ∩{x :|x i |≥s }=P P −1(C )∩{x :|x i |≥s }and also P −1(A )+B n +k 1⊂P −1(A +B n1).From Lemma 4.1we haveρk P −1(A )+tB n +k1∩ x :|x i |≥u −t ≥e t/2ρk P −1(A )∩ x :|x i |≥u ,and thus˜νk A +tB n1∩ x :|x i |≥u −t ≥e t/2˜νk A ∩ x :|x i |≥u .When k →∞,we have ˜νk (C )→νn (C )for any set C ∈B (R n ).Thus by goingto the limit we get the assertion.20Proposition 4.4.For any t >0and any n ∈N we haveA +tB n 1|x |2dνn (x )≥e t/2A(|x |−t√y −t )2+is convex on [0,∞),hencen i =1(|x i |−t )2+=n i =1f (x 2i )≥nf1n )2+Lemma 4.5.Suppose that A ⊂{x ∈R n :|x |≥5t√8e t/2νn (A ).Proof.LetA k :=A ∩{x :5t√n +2tk },k =1,2,....Then A k +tB n1⊂{x :5t√n +t (2k +1)},henceνn (A +tB n1)≥1n +t (2k +1) 2νn (A k +tB n1)≥A k +tB n 1|x |2dνn (x )≥e t/2A k|x |−t√n +2t (k −1) 2νn (A k ).21Thusνn (A k +tB n1)≥ 4t √5t √4e t/2νn (A k ).andνn (A +tB n1)≥14e t/2νn (A k )=1nB n2 ≥1nB n 2+tB n1)=∅.Proof.Let A k denote A +10kB n1for k =0,1,....If for any 0≤k ≤t/10we have νn(A k ∩50√nB n 2.From Lemma 4.5we haveνn (A k +1)≥νn (A ′k +10B n1)≥116e 5νn (A k )≥e 2νn (A k ).By a simple induction we get νn (A k )≥e 2k νn (A )for any k ≤t/10.Thus we get νn (A +tB n1)≥νn A ⌊t/10⌋ ≥e 2⌊t/10⌋νn (A )≥e t/10ν(A ).5Uniform measure on B n pIn this section we will prove the infimum convolution property IC(C )for B npballs.Recall that νnp is a product measure,while µp,n denotes the uniformmeasure on r p,n B np .We haver −np,n=|B n p |=2n Γ(1+1/p )nn n/p (Proposition 5.1.For any p ≥1and t ∈R we haveB t (νp )∼{x :f p (|x |)≤t },and Λ⋆νp (t/C )≤f p (|t |)≤Λ⋆νp (Ct ),where f p (t )=t 2for t <1and f p (t )=t p for t ≥1.Proof.We shall use the facts proved in Section 3to approximate B t (νp ).Notethat νp is log-concave (as its density is log-concave)and symmetric.It is 1–regular from Proposition 3.8.Alsoσ2p :=R x 2dνp (x )=1p )p )∼1for p ∈[1,∞).The measure ˜νp with the density σp dνp (σp x )is isotropic,hencePropositions 3.3and 3.6yield B t (˜νp )∼√t,√t,√2γpR|u |t|x |t e −|x |pdx ≤1= u ∈R :|u |≤tp )p)∼{u ∈R :|u |≤t −1/p }.Thus Z t (νp )∼[−t 1/p ,t 1/p ]for |t |≥1,so by Propositions 3.2and 3.5,B t (νp )∼[−t 1/p ,t 1/p ].Hence,for all t ≥0we have {x :f p (|x |)≤t }∼{x :Λ⋆νp (x )≤t },so Λ⋆νp (t/C )≤f p (t )≤Λ⋆νp (Ct ).As Λ⋆νp is symmetric,the proof is finished.Corollary 5.2.For any t >0and n ∈N we haveB t (νn p )∼ √tB n 2∩t 1/p B np for p ≥2.Proof.By Proposition 5.1,B t (νnp )={x ∈R n :Λ⋆νp(x i )≤t }∼{x ∈R n : f p (|x i |)≤t }.Simple calculations show that {x ∈R n : f p (|x i |)≤t }∼t 1/2B n 2+t 1/p B n p forp ∈[1,2]and {x ∈R n : f p (|x i |)≤t }∼t 1/2B n 2∩t 1/p B np for p ≥2.Proposition 5.3.For any t ∈[0,n ],p ≥1and n ∈N we have B t (µp,n )∼B t (νn p ).Proof.For t <1we use Propositions 3.3and 3.6.Both µp,n and νn p are sym-metric,log–concave measures,and both can be rescaled as in Proposition 5.1to be isotropic,thus B t (µp,n )∼√(max {n,t })1/p| a,x |tdνn p (x )1/t(21)23for any p,t≥1and a∈R n.Note that as r p,n∼n1/p,this simply means the equivalence of t-th moments ofµp,n andνp,n for t∈[0,n].Thus M t(µp,n)∼M t(νp,n)for t≤n and therefore B t(µp,n)∼B t(νp,n).Remark5.4.It is not hard to verify that B t(µp,n)∼r p,n B n p for t≥n.5.1Transports of measureWe are now going to investigate two transports of measure.They will combineto transport a measure with known concentration properties(νn orνn2,that is the exponential or Gaussian measure)to the uniform measureµp,n.We will investigate the contractive properties of these transports with respect to various norms.Our motivation is the following:Remark5.5.Let U:R n→R n be a map such thatU(x)−U(y) p p≥δ x−y q q for all x∈R n,y∈A.ThenU A+t1/q B n q ⊃U R n ∩ U(A)+δ1/p t1/p B n p . Analogously ifU(x)−U(y) p p≤δ x−y q q for all x∈R n,y∈AthenU A+t1/q B n q ⊂U(A)+δ1/p t1/p B n p.Proof.Let us prove thefirst statement,the second proof is almost identical. Suppose U(x)∈U(A)+δ1/p t1/p B n p.Then there exists y∈A such that U(x)−U(y) p p≤δt.From the assumption we have t≥ x−y q q,which means x∈A+t1/q B n q,and U(x)∈U(A+t1/q B n q).Thefirst transport we introduce is the radial transport T p,n which transforms the product measureνn p ontoµp,n–the uniform measure on r p,n B n p.We will show this transport is Lipschitz with respect to theℓp norm and Lipschitz on a large set with respect to theℓ2norm for p≤2.Definition5.6.For p∈[1,∞)and n∈N let f p,n:[0,∞)→[0,∞)be given bythe equations0e−r p r n−1dr=(2γp)n f p,n(s)0r n−1dr(22) and T p,n(x):=xf p,n( x p)/ x p for x∈R n.Let usfirst show the following simple estimate.Lemma5.7.For any q>0and0≤u≤q/2,q u0e−t t q−1dt≤e−u u q 1+2u。
雅思口语Part1参考答案之Concentration雅思口语Part1参考答案之Concentration1. Is it important to focus on things?Most likely yes. For most of us, if we don't focus on anything, we start to feel empty, question life and lose the will. Like how a shark dies if it stops swimming.可能是重要的。
对于我们多数人来说，如果我们不集中在任何事情上，我们会觉得空虚，会质疑生活并丧失意志。
这就好比鲨鱼停止游泳会如何死去一样。
(鲨鱼必须不停游泳，让水通过鳃，否则就会下沉窒息。
)2. When do people need to focus?Well, we don’t actually need to focus on almost eve rything. Keeping your attention on what is most important in your life is one of the most essential ingredients if you want to be able to stick with your goals.其实，我们不需要对任何事情都集中精神。
如果你想坚持自己的目标，那么保持注意力在生活中最重要的事情上是必备要素之一。
3. Is it easy to concentrate on things?As long as you understand the word “concentration”, then yes. Concentration means：“great and constantdiligence and attention” This is interesting! If concentration is related to attention then that means that we should be able to improve our concentration by simply becoming more attentive.如果你能明白“专心”的意思，就没问题。
Concentration is a vital skill that plays a significant role in various aspects of life, from academic success to professional achievements.Here are some key points that can be included in an essay on the importance of concentration:1.Definition of Concentration:Begin by defining what concentration means.It is the ability to focus ones attention on a single task or activity without being easily distracted.2.Importance in Education:Discuss how concentration is crucial for students to absorb and retain information during lectures,while studying,or completing assignments.3.Enhanced Learning:Concentration allows for deeper understanding and better retention of knowledge,leading to improved grades and a more profound grasp of complex subjects.4.Productivity at Work:In a professional setting,concentration is essential for completing tasks efficiently,meeting deadlines,and achieving highquality work output.5.Problem Solving:Concentration is key to effective problemsolving,as it enables individuals to think critically and creatively without being sidetracked by irrelevant thoughts or distractions.6.Mental Health Benefits:Being able to concentrate can reduce stress and anxiety,as it helps individuals to stay focused on the task at hand rather than worrying about unrelated issues.7.Strategies for Improving Concentration:Offer practical advice on how to improve concentration,such as setting clear goals,eliminating distractions,practicing mindfulness, and taking regular breaks to avoid burnout.8.Technological Impact:Address the impact of technology on concentration,noting how digital distractions can hinder focus but also how technology can be harnessed to improve it through productivity tools and apps.9.Cultural and Social Factors:Explore how cultural and social factors may influence concentration,such as the importance of quiet study spaces in some cultures or the role of community in supporting focused work.10.Longterm Consequences of Lack of Concentration:Discuss the potential negative outcomes of not being able to concentrate,such as poor academic performance,decreased work productivity,and increased likelihood of errors.11.Personal Accounts and Anecdotes:Include personal experiences or anecdotes that illustrate the importance of concentration,whether its a story of overcoming distractions or an account of how concentration led to a significant achievement.12.Conclusion:Summarize the key points and emphasize the importance of cultivating the skill of concentration for overall success in life.Remember to structure your essay with a clear introduction,body paragraphs that explore each point in detail,and a conclusion that ties everything e evidence and examples to support your arguments and make your essay engaging and persuasive.。
contemplation concentration -回复什么是沉思集中？沉思集中是指将思维、意识和精力集中在特定的主题或问题上的能力。
它是一种思维过程，通过专注和深入思考，使我们更好地理解和分析各种问题，以便找到最佳的解决方案。
沉思集中要求我们通过冥想和专注来控制我们的思维，以便我们可以更理性、更全面地思考问题。
下面是沉思集中的步骤：第一步：创造良好的环境为了进行有效的沉思集中，我们需要一个安静、舒适且没有干扰的环境。
选择一个安静的地方，远离噪音和干扰，确保我们可以专注于思考。
我们可以关闭电视、手机，窗帘上遮光，创造一个让我们感到舒适和放松的环境。
第二步：冥想和放松一旦我们进入沉思集中的环境，我们可以通过冥想和放松来准备自己。
冥想有助于减轻压力和焦虑，增加内心的平静和专注。
我们可以通过深呼吸、闭上眼睛，让自己进入冥想状态。
冥想可以帮助我们清空头脑，准备好接受新的思考和洞察。
第三步：选择一个主题或问题在沉思集中时，我们需要选择一个明确的主题或问题来思考。
这个主题或问题应该是具体和有挑战性的，以便我们可以深入探索和分析。
我们可以选择个人发展、道德伦理、工作问题等不同类型的主题。
确保我们对所选择的主题或问题有足够的兴趣和了解，这样我们才能更加专注和投入。
第四步：自我反思和提问一旦我们选定了主题或问题，我们可以开始自我反思和提问。
自我反思是指对自己的思维过程和信念进行反思和评估。
我们可以问自己关于主题或问题的一系列问题，以深入了解自己的观点和思维方式。
自我反思有助于我们了解我们的强项和弱项，以及我们的偏见和盲点。
第五步：收集信息和思考在自我反思和提问的基础上，我们可以开始收集相关的信息和数据，并进行思考和分析。
我们可以阅读相关的书籍、文章或观点，与他人讨论和交流，从不同的角度来思考问题。
确保我们收集到的信息是可靠和有用的，并将其与我们之前的观点进行比较和对比。
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（1092）溶出度试验的开发和验证【中英文对照版】之五兆芳芳创作INTRODUCTION前言Purpose目的The Dissolution Procedure: Developmentand Validation <1092> provides a comprehensive approach covering items to considerfor developing and validating dissolution procedures and the accompanyinganalytical procedures. It addresses the use of automation throughout the testand provides guidance and criteria for validation. It also addresses thetreatment of the data generated and the interpretation of acceptance criteriafor immediate and modifiedrelease solid oral dosage forms.溶出实验:开发和验证（1092）指导原则提供了在溶出度办法开发和验证进程中以及采取相应阐发办法时需要考虑的因素.本指导原则贯串溶出度实验的全部进程，并对办法提供了指导和验证尺度.同时它还涉及对普通制剂弛缓释制剂所生成的数据和接受尺度进行说明.Scope规模Chapter <1092> addresses the development andvalidation of dissolution procedures, with a focus on solid oral dosage forms.Many of the concepts presented, however, may be applicable to other dosageforms and routes of administration. General recommendations are given with theunderstanding that modifications of the apparatus and procedures as given in USPgeneral chapters need to be justified.<1092>章节讨论了溶出度实验的开发和验证，重点是口服固体制剂.所提出的许多概念也可能适用于其他剂型和给药途径.关于设备和办法的修改部分在USP通则中给出了公道的说明.The organization of <1092> follows the sequence of actions often performed inthe development and validation of a dissolution test. The sections appear inthe following sequence.在进行溶解度实验的开发和验证时，常遵循指导原则<1092>，具体内容如下：1. PRELIMINARY ASSESSMENT (FOR EARLY STAGES OF PRODUCTDEVELOPMENT/DISSOLUTION METHOD DEVELOPMENT)1.前期评估（对产品开发以及溶出度办法开发的前期研究评估）1.1 Performing Filter Compatibility1.2 Determining Solubility and Stability of DrugSubstance in Various Media1.3 Choosing a Medium and Volume1.4 Choosing an Apparatus1.4溶出设备选择（桨法和篮法以及其他办法）2. METHOD DEVELOPMENT2.1 Deaeration2.2 Sinkers2.3 Agitation2.4 Study Design2.4.1 TimePoints2.4.2 Observations2.4.3 Sampling2.4.4 Cleaning2.5 Data Handling2.6 Dissolution Procedure Assessment3. ANALYTICAL FINISH3.1 Sample Processing3.1 样品处理3.2 Filters3.2 过滤3.3 Centrifugation3.3 离心3.4 Analytical Procedure3.4 阐发办法3.5 Spectrophotometric Analysis3.5 光谱阐发3.6 HPLC4. AUTOMATION4.1 Medium Preparation4.2 Sample Introduction and Timing4.3 Sampling and Filtration4.4 Cleaning4.4 清洗4.5 Operating Software and Computation of Results5. VALIDATION5.1 Specificity/Placebo Interference5.1专属性/安抚剂（辅料）搅扰5.2 Linearity and Range5.3 Accuracy/Recovery5.4 Precision5.4.1 REPEATABILITY OF ANALYSIS5.4.2 INTERMEDIATE PRECISION/RUGGEDNESS 5.4.3 REPRODUCIBILITY5.5 Robustness5.6 Stability of Standard and Sample Solutions5.7 Considerations for Automation6. ACCEPTANCE CRITERIA6.1 ImmediateRelease Dosage Forms6.2 DelayedRelease Dosage Forms6.3 ExtendedRelease Dosage Forms6.4 Multiple Dissolution Tests6.5 Interpretation of Dissolution Results6.5.1 IMMEDIATERELEASE DOSAGE FORMS6.5.2 DELAYEDRELEASE DOSAGE FORMS6.5.3 EXTENDEDRELEASE DOSAGE FORMS1. PRELIMINARYASSESSMENT (FOR EARLY STAGES OF PRODUCT DEVELOPMENT/DISSOLUTION METHODDEVELOPMENT)1. 前期评估（产品开发/溶出度办法开发的初期阶段）Beforemethod development can begin, it is important to characterize the molecule sothat the filter, medium, volume of medium, and apparatus can be chosen properlyin order to evaluate the performance of the dosage form.在开始溶出办法开发之前，我们对用以评价制剂溶出行动的滤膜、溶出介质、溶出介质体积和溶出设备进行适当的筛选是很是重要的.1.1 Performing Filter CompatibilityFiltrationis a key samplepreparation step in achieving accurate test results. Thepurpose of filtration is to remove undissolved drug and excipients from thewithdrawn solution. If not removed from the sample solution, particles of thedrug will continue to dissolve and can bias the results. Therefore, filteringthe dissolution samples is usually necessary and should be done immediately ifthe filter is not positioned on the cannula.为取得准确试验结果，过滤是样品制备的一个关头步调.过滤的目的是为了除去溶出液中未溶解的药物和辅料.如果不把未溶解的药物和辅料从样品溶液中除去，那么未溶解的药物颗粒将会持续溶解使试验结果出现偏差，因此，如果取样管中没有过滤器，应立即对溶出度样品进行过滤. Filtration also removes insolubleexcipients that may otherwise interfere with the analytical finish. Selectionof the proper filter material is important and should be accomplished, andexperimentally justified, early in the development of the dissolutionprocedure. Important characteristics to consider when choosing a filtermaterial are type, filter size, and pore size. Thefilter that is selectedbased on evaluation during the early stages of dissolution procedure developmentmay need to be reconsidered at a later time point. Requalification has to beconsidered after a change in composition of the drug product or changes in thequality of the ingredients (e.g. particle size of microcrystalline cellulose).过滤也可除去可能会搅扰阐发测定的不溶性辅料.选择适当的过滤资料是很是重要，应该在早期溶出办法开发的进程中通过实验确定和完成.在选择滤膜时有需要重点考虑滤膜的资料、型号和孔径大小.通常对早期阶段溶出办法开发进程的评价选择过滤器，但在前期试验中如果制剂成分改动或组成成分质量变更可能需要重新考虑过滤器，（例如：微晶纤维素粒径的改动）.Examples of filters used in dissolutiontesting can be cannula filters, filter disks or frits, filter tips, or syringefilters. The filter material has to be compatible with the media and themon pore sizes range from 0.20 to 70 mm, however, filters of other poresizes can be used as needed. If the drug substance particle size is very small(e.g., micronized or nanoparticles), it can be challenging to find a filterpore size that excludes these small particles.用于溶出试验的过滤器有管路过滤器、过滤盘或玻璃过滤器、滤头或针头式过滤器.过滤资料必须与介质和药物相适合.罕有孔径大小规模：0.20～70μm，如果需要也可使用其他孔径大小的过滤器.如果原料药的粒度很小（例如，微分化颗粒或纳米颗粒），找到一个适合的过滤器过滤这些小颗粒至今仍具有挑战性.Adsorption of the drug(s) by the filtermay occur and needs to be evaluated. Filter materials will interact withdissolution media to affect the recovery of the individual solutes and must beconsidered on a casebycase basis. Different filter materials exhibitdifferent drugbinding properties. Percentage of drug loss from the filtratedue to binding may be dependent on the drug concentration. Therefore theadsorptive interference should be evaluated on sample solutions at differentconcentrations bracketing the expected concentration range. Where the drugadsorption is saturable, discarding an initial volume of filtrate may allow thecollection of a subsequent solution that approaches the original solutionconcentration. Alternative filter materials that minimize adsorptiveinterference can usually be found. Prewetting of the filter with the medium maybe necessary. In addition, it is important that leachables from the filter donot interfere with the analytical procedure. This can beevaluated by analyzingthe filtered dissolution medium and comparing it with the unfiltered medium.过滤时可能会产生药物的吸附，需要进行评估.过滤资料将与溶出介质相互作用，影响每个溶质的收受接管率应该按照具体问题进行考虑.不合的过滤资料表示出与药物结合的不合特性.由于药物与滤膜结合引起药物从滤液中损失的比例，可能依赖于药物浓度.因此，应采取预期浓度规模内不合浓度的样品溶液来评估滤膜吸附搅扰.由于药物吸附是可饱和的，弃去一定体积的初滤液，收集续滤液，以达到接近原来的溶液浓度的样品也是可取的.通常选择适合的过滤资料，最大限度地削减滤膜吸附搅扰，润湿滤膜对削减吸附也是需要的.此外，过滤后的溶出物不搅扰阐发检测也是很是重要的，这可以通过过滤后的溶出介质过滤与未过滤的溶出介质进行比较，评估滤膜是否搅扰阐发测定.The filter size should be based on thevolume to be withdrawn and the amount of particles to be separated. Use of thecorrect filter dimensions will improve throughput and recovery, and also reduceclogging. Use of a large filter for smallvolume filtration can lead to loss ofsample through holdup volume, whereas filtration through small filter sizesneeds higher pressures and longer times, and the filters can clog quickly.按照要过滤样品溶液的体积以及样品溶液中颗粒的量选择滤膜孔径.使用正确的滤膜孔径将提高溶液的通过率和收受接管率，并削减滤膜堵塞.使用大孔径滤膜过滤小体积溶液，能够导致样品溶液损失量过大而收集不到所用样品量；使用小孔径滤膜过滤，需要更高的压力和较长的时间，并且溶液迅速堵塞滤膜.Filters used for USP Apparatus 4 needspecial attention because they are integrated in the flowthrough process.Undissolved particles may deposit on the filters, creating resistance to theflow.USP仪器4中使用的过滤器需要特别注意，因为它们在流动进程中使用.不溶颗粒会沉积在过滤器，产生流动阻力. In the case of automated systems,selection of the filter with regard to material and pore size can be done in asimilar manner to manual filtration. Flow rate through the filter and cloggingmay be critical for filters used in automated systems. Experimentalverification that a filter isappropriate may be accomplished by comparing the responses for filtered andunfiltered standard and sample solutions. This is done by first preparing asuitable standard solution and a sample solution. For example, prepare atypical dissolution sample in a beaker and stir vigorously witha magneticstirrer to dissolve the drug load completely.For standard solutions, comparethe results for filtered solutions (after discarding the appropriate volume) tothose for the unfiltered solutions. For sample solutions, compare the resultsfor filtered solutions (after discarding the appropriate volume) to those forcentrifuged, unfiltered solutions.在自动化系统的情况下，关于过滤器滤膜资料和孔径大小可以用类似的方法通过手动过滤进行选择.在自动化系统中通过过滤器的流量和过滤器的堵塞可能是至关重要的.通过试验比较过滤和未过滤的尺度溶液和样品溶液的含量不同，验证该过滤器是适合的.首先制备一个适合的尺度溶液和样品溶液.例如，在烧杯中制备一个尺度溶解样品，用磁力搅拌器搅拌使药物完全溶解.对于尺度溶液，比较过滤溶液（弃去的适当体积后）和未过滤溶液的含量测定结果；对于样品溶液，比较过滤（弃去适当体积后）、离心、未过滤样品溶液的含量测定结果.1.2 Determining Solubility and Stability of DrugSubstance in Various MediaPhysical and chemical characteristics of the drug substance need to be determinedas part of the process of selecting the proper dissolution medium. Whendeciding the composition of the medium for dissolution testing, it is importantto evaluate theinfluence of buffers, pH, and if needed, different surfactantson the solubility and stability of the drug substance. Solubility of the drugsubstance is usually evaluated by determining the saturation concentration ofthe drug in different media at 37°using the shakeflask solubility method(equilibrium solubility). To level out potential ion effects between the drugand the buffers used in the media, mixtures of hydrochloric acid and sodiumhydroxide are used to perform solubility investigations; this is in addition tothe typical buffer solutions. In certain cases, it may be necessary to evaluatethe solubility of the drug at temperatures other than 37° (i.e., 25°). The pHof the clear supernatant should be checked to determine whether the pH changesduring the solubility test. Alternative approaches for solubility determinationmay also be used.在选择适合溶出介质的进程中，需要确定原料药的物理化学特性.当需要确定溶出度试验中溶出介质的组成时，有需要评估缓冲液、pH值、以及不合的概略活性剂（如果需要）对药物的溶解度和稳定性的影响.在37℃温度条件下，采取摇瓶溶解法（平衡溶解度）测定原料药在不合介质中的饱和浓度，来评估药物的溶解性.为了消除溶出介质中药物弛缓冲液之间离子的潜在影响，使用盐酸和氢氧化钠的混杂物对溶解度进行研究，这是一种典型的缓冲溶液.在某些情况下，评估药物在37℃以外条件下（即，25℃）的溶解度可能也是需要的.在溶解度试验进程中应查抄上清溶液的pH值，以确定在溶解进程中pH值是否改动.也可使用其他可供选择的办法进行溶解度测定.Typical media for dissolution mayinclude the following (not listed in order of preference): diluted hydrochloricacid, buffers (phosphate or acetate) in the physiologic pH range of 1.2–7.5, simulatedgastric or intestinal fluid (with or without enzymes),and water. For somedrugs, incompatibility of the drug with certain buffers or salts may influencethe choice of buffer. The molarity of the buffers and acids used can influencethe solubilizing effect, and this factor may be evaluated.溶出的典型介质包含（未依照优先顺序列出）：稀盐酸、在生理pH值规模为1.27.5缓冲溶液（磷酸盐或醋酸盐）、模拟胃液或肠液（含有或不含有酶）和水.对于一些药物，与药物不相容的特定缓冲液或盐可能会影响缓冲剂的选择.所使用的缓冲液和酸的体积摩尔浓度能够改动药物的增溶作用，这个因素也需要评估.Aqueous solutions (acidic or buffersolutions) may contain a percentage of a surfactant [e.g., sodium dodecylsulfate (SDS),polysorbate, or lauryldimethylamine oxide] to enhance thesolubility of the drug. The surfactants selected for thesolubilityinvestigations should cover all common surfactant types, i.e., anionic,nonionic, and cationic. When a suitable surfactant has been identified,different concentrations of that surfactant should be investigated to identifythe lowest concentration neededto achieve sink conditions. Typically,the surfactant concentration is above its critical micellar concentration(CMC). Table 1 shows a list of some of the surfactants used indissolution media. Approximate CMC values are provided with referenceswhenavailable. The list is not comprehensive and is not intended to exclude surfactantsthat are not listed. Other substances, such ashydroxypropyl b cyclodextrin,have been used as dissolution media additives to enhance dissolution of poorlysoluble compounds.The U.S. Food and Drug Administration (FDA) maintains adatabase of dissolution methods, including information on dissolution mediathat have been used (1). Typically, the amount of surfactant added issufficient to achieve sink conditions in the desired volume of dissolutionmedium.有时候水溶性介质中（酸性水溶液或缓冲溶液）可能添加一定比例的概略活性剂（如十二烷基硫酸钠（SDS），聚山梨醇酯，或十二烷基二甲基氧化胺）以提高药物的溶解度.选择用于溶解度研究的概略活性剂时应涵盖所有经常使用种类的概略活性剂，比方阴离子、非离子型和阳离子，当已经确定一个适合的概略活性剂时，应对概略活性剂的不合浓度进行研究，以确定达到漏槽条件所需的最低浓度.一般情况下，概略活性剂的浓度高于它的临界胶束浓度（CMC）.表1列出了溶出介质中经常使用的概略活性剂，表中提供了CMC的近似临界值，以便我们参考，此外，表中所列概略活性剂其实不全面，不克不及排除未列出的概略活性剂.其他概略活性剂，如羟丙基β环糊精，已被用来作为溶出介质添加剂提高难溶性化合物的溶解度，美国食品药品办理局（FDA）溶出度数据库中，已经收载含有羟丙基β环糊精的溶出介质（1）.通常情况下，概略活性剂的参加量以满足达到漏槽条件所需的溶出介质体积.It is important to control thegrade and purity of surfactants because use of different grades could affectthe solubility of the drug. For example, SDS is available in both a technicalgrade and a highpurity grade. Obtaining polysorbate 80 from different sourcescan affect its suitability when performing highperformance liquidchromatography (HPLC) analysis.由于使用不合级此外概略活性剂会影响药物的溶解度，因此要控制概略活性剂的级别和纯度.例如，SDS只有在产业级和高纯度级才可以使用.在使用HPLC办法进行阐发时，不合来源的聚山梨酯（吐温）80会影响它的适用性. There may be effects of counterions orpH on the solubility or solution stability of the surfactant solutions. Forexample, a precipitate forms when the potassium salt for the phosphate bufferis used at a concentration of 0.5 M in combination with SDS. This can beavoided by using the sodium phosphate salt when preparing media with SDS.反离子或pH值可能会影响概略活性剂溶液的溶解性或稳定性.例如，当含有SDS的磷酸盐缓冲液中钾盐浓度为0.5mol/L时，就形成了沉淀析出，但是使用磷酸钠制备含有SDS的介质时，可以避免这种现象产生.Table 1. Commonly Used Surfactants with Critical MicelleConcentrations表1 罕有概略活性剂的临界胶束浓度Routinely, the dissolution medium is buffered; however, the u搜索引擎优化f purified water as the dissolution medium is suitable for products with adissolution behavior independent of the pH of the medium. There are severalreasons why purified water may not be preferred. The water quality can varydepending on its source, and the pH of the water is not as strictly controlledas the pH of buffer solutions. Additionally, thepH can vary from day to dayand can also change during the run, depending on the drug substance andexcipients. Use of an aqueous–organic solvent mixture as a dissolution mediumis discouraged; however,with proper justification this type of medium may beacceptable.通常，溶出介质为缓冲盐溶液，但是，对于非pH值依赖性的制剂可以使用纯化水作为溶出介质.不推荐使用纯化水作为溶出介质的原因：水的质量变更取决于它的来源，而水的pH值不像缓冲溶液能够严格控制；此外，若药物和辅料的溶出对pH值敏感时需要考虑使用缓冲液.另外使用水有机溶剂混杂物作为溶出介质也是不推荐的，但是，特殊情况下（有充分适当的理由），也是可以接受的. Investigations of the stability of thedrug substance should be carried out, when needed, in the selected dissolutionmedium with excipients present, at 37°. This elevated temperature has thepotential to decrease solution stability (degradation). Stability should allowfor sufficient time to complete or repeat the analytical procedure. Physicalstability may be of concern when precipitation occurs because of lowersolubility at room or refrigerated temperature.需要时，应该对原料药的稳定性进行考察，在所选择的溶出介质中参加辅料，在37℃条件下进行考察.这种升高的温度会潜在的下降溶液的稳定性（降解）.稳定性试验应考虑到有足够的时间来完成或重复阐发进程.当因室温或冷藏贮存时下降药物的溶解度而产生沉淀时，物理稳定性也需要存眷.1.3 Choosing aMedium and VolumeWhen developing a dissolution procedure, one goal is to have sinkconditions, which are defined as having a volume of medium at least three timesthe volume required to form a saturated solution of drug substance. When sinkconditions are present, it is more likely that dissolution results will reflectthe properties of the dosage form. A medium that fails to provide sinkconditions may be acceptable if it is appropriately justified. The compositionand volume of dissolution medium are guided by the solubility investigations.For example, the choice and concentration of a surfactant need to be justifiedfrom the solubility data and the dissolution profiles.当开发一个溶出试验办法时，首先要满足漏槽条件，漏槽条件定义为溶出介质体积至少为药物达到饱和溶液所需体积的三倍.当满足漏槽条件后，溶出度结果能够更好的反应药物制剂的质量.在适当条件下，介质不满足漏槽条件也是可以接受的.溶解介质的组成和体积应按照溶解度的试验结果进行调整.例如，概略活性剂种类和浓度选择，需要按照药物溶解度数据和溶出曲线进行调整.The use of enzymes in the dissolutionmedium is permitted, in accordance with Dissolution <711>, when dissolution failures occur as a result of crosslinkingwith gelatin capsules or gelatincoated products. A discussion of thephenomenon of crosslinking and method development using enzymes can be found inCapsules–Dissolution Testing and Related Quality Attributes<1094>. Validation should be performed with the method using enzymesaccording to section 5. Validation.当交联明胶胶囊或明胶包衣的制剂溶出失败时，在溶出介质中允许参加酶，这同溶出度<711>指导原则一致.在“Capsules–Dissolution Testing and RelatedQuality Attributes<1094>”中可以找到产生交联现象的讨论和采取酶进行办法开发的研究.按照第5节验证，使用酶办法依照溶出度办法学验证的要求进行验证.Another option is to use media thatfollow more closely the composition of fluids in the stomach and intestinaltract. These media may contain physiological surfaceactive ingredients, suchas taurocholates. The media also may contain emulsifiers (lecithin) andcomponents such as saline solution that increase osmolality. Also, the ionicstrength or molarity of the buffersolutions may be manipulated. The media aredesigned to represent the fed and fasted state in the stomach and smallintestine.These media may be very useful in modeling in vivo dissolutionbehavior of immediaterelease (IR) dosage forms, in particular those containinglipophilic drug substances, and may help in understanding the dissolutionkinetics of the product related to the physiological makeup of the digestivefluids. Results of successful modeling of dissolution kinetics have beenpublished,mainly for IR products. In the case of extendedrelease dosage formswith reduced effect of the drug substance on dissolution behavior, the use ofsuch media needsto be evaluated differently. In vitro performance testing doesnot necessarily require media modeling the fasted and postprandial states (12,13).另一种选择是使用更贴近于胃和肠道流体组分的介质.这些溶出介质可以含有生理概略活性成分，如牛黄胆酸.这些溶出介质也可能含有乳化剂（卵磷脂）和增加渗透压的组分，比方生理盐水溶液.同时，缓冲液的离子强度或体积摩尔浓度是可以控制的.设计的溶出介质模拟了进食和空腹状态下的胃和肠内状态.这些溶出介质对速释制剂（IR）成立体内溶解行动模型方面是很是有用的，特别是这些速释制剂中含有脂溶性的原料药，可能有助于理解和消化液的生理组成相关的制剂溶出动力学.溶解动力学的模型已成功成立，主要用于速释制剂.对缓释剂型削减药物溶解行动的影响，使用的这些溶出介质需要有区别地进行评估.体外性能测试其实不一定需要在空腹和餐后状态成立溶出介质模型. An acid stage is part of the testing ofdelayedrelease products by Method A or Method B in <711>. For drugs with acid solubility less than 10% of the labelclaim or drugs that degrade in acid the usefulness of the acid stage indetecting a coating failure is compromised. This would be handled on acasebycase basis. Possible resolutions include the addition of surfactant tothe acid stage, or adjustment of the specifications.对于肠溶制剂，酸中释放度是溶出度的一部分（<711>办法A或办法B）.针对于药物标签中说明在酸中释放度不得过标示量的10%或避免酸液中降解而进行抗酸包衣的药物.按照具体情况进行解决，可能的解决计划包含：酸性介质中添加概略活性剂或调整质量尺度）During selection of the dissolutionmedium, care should be taken to ensure that the drug substance is suitablystable throughout the analysis. In some cases, antioxidants such as ascorbicacid may be used in the dissolution medium to stabilize the drug. There areoccasions where such actions are not sufficient. For compounds that rapidlydegrade to form a stable degradant,monitoring the degradant alone or incombination with a drug substance may be more suitable than analyzing only thedrug substance. In situ spectroscopic techniques tend to be less affected bydegradation when compared with HPLC analysis (including UHPLC and other liquidchromatographic approaches).在选择溶解介质时，应注意采纳措施确保原料药在整个阐发进程中的稳定性.在某些情况下抗氧化剂，如抗坏血酸的，可用于在溶出介质中，以包管药物的稳定性.有些时候参加这些抗氧剂是不敷的.化合物快速降解形成稳定的降解物，单独监测降解物或与原料药联合监控可能比只阐发原料药更适合.与高效液相色谱阐发比较（包含超高效液相色谱等液相色谱法），原位光谱阐发受降解的影响较小.For compendial Apparatus 1 (basket) andApparatus 2 (paddle), the volume of the dissolution medium can vary from 500 to1000 mL. Usually, the volume needed for the dissolution test can be determinedin order to maintain sink conditions. In some cases, the volume can be increased tobetween 2 and 4 L, using larger vessels and depending on the concentration andsink conditions of the drug; justification for this approach is expected. Inpractice, the volume of the dissolution medium is usuallymaintained within the compendial rangegiven above. Alternatively, it may be preferable to switch to other compendialapparatus, such as a reciprocating cylinder (Apparatus 3), reciprocating holder(Apparatus 7), or flowthrough cell (Apparatus 4).Certain applications may require lowvolumes of dissolution media (e.g., 100–200 mL) when the use of a paddle orbasket is preferred. In these cases, an alternative, noncompendial apparatus(e.g., smallvolume apparatus) may be used.对于药典仪器1（篮法）和仪器2（桨法），溶出介质的体积可以从500到1000毫升不合.通常情况下，溶出介质的体积应当满足漏槽条件.在某些情况下，按照药物的浓度和漏槽条件，可使用较大的溶出杯，体积可以增加至2～4升（这种办法必须有充分的理由）.实际上，溶出介质的体积通常在药典规则规模内.可供选择时，选用药典规则的其他仪器也是可取的，如往复式气缸（仪器3），往复架（仪器7），或流通池（仪器4）.当某些仪器需要较少体积的溶出介质（例如，100200毫升）时，首选桨法或篮法.在这些情况下，非药典仪器仪器（例如，体积小的仪器）也可以选择使用.1.4 Choosingan Apparatus1.4溶出设备选择（桨法和篮法以及其他办法）The choice ofapparatus is based on knowledge of the formulation design and the practicalaspects of dosage form performance in the in vitro test system. In general, acompendial apparatus should be selected.按照对处方设计的认知和体外试验剂型的实际特点选择仪器.一般来说，首选药典仪器.For solid oral dosage forms, Apparatus1 and Apparatus 2 are used most frequently. When Apparatus 1 or Apparatus 2 isnot appropriate, another official apparatus may be used. Apparatus 3(reciprocating cylinder) has been found especially useful for chewable tablets,soft gelatin capsules, delayedrelease dosage forms, and nondisintegratingtypeproducts, such as coated beads. Apparatus 4 (flowthrough cell) may offeradvantages for modifiedrelease dosage forms and immediaterelease dosage formsthat contain active ingredients with limited solubility. In addition, Apparatus4 may have utility for multiple dosage form types such as soft gelatincapsules, beaded products, suppositories, or depot dosage forms, as well assuspensiontype extendedrelease dosage forms. Apparatus 5 (paddle over disk)and Apparatus 6 (rotating cylinder) are useful for evaluating and testingtransdermal dosage forms. Apparatus 7 (reciprocating holder) has application tonondisintegrating, oralmodifiedrelease dosage forms, stents, and implants,as well as transdermal dosage forms. For semisolid dosage forms, the generallyused apparatus include the vertical diffusion cell, immersion cell, andflowthrough cell apparatus with the insert for topical dosage forms (seeSemisolid Drug Products—Performance Tests <1724>).对于口服固体制剂，仪器1和仪器2使用最多.当仪器1或仪器2不适用时，可以使用其他官方仪器.已发明仪器3（往复气缸）适用于咀嚼片、软胶囊、缓释制剂和不崩解型产品（如包衣小球）.仪器4（流通池）对活性成分的溶解度有限的缓释剂型和速释剂型提供了良多优势.此外，仪器4可用于多种剂型类型，如软胶囊，微球制剂，栓剂，或贮库型产品，以及悬浮型缓释剂型.仪器5（桨盘）和仪器6（旋转缸）适用于评价和测试的经皮给药制剂.仪器7（往复架）适用非崩解制剂，口服缓释剂型，支架，和植入物，以及透皮制剂.半固态剂型，经常使用的仪器包含立式扩散池，浸入细胞，流通单元仪器适用局部制剂（see Semisolid DrugProducts—Performance Tests <1724>）.Some changes can be made to thecompendial apparatus; for example, a basket mesh size other than the typical40mesh basket (e.g., 10, 20, or 80mesh) may be used when the need isclearly documented by supporting data. Care must be taken that basketsareuniform and meet the dimensional requirements specified in <711>.对药典仪器配件也可以进行一些调整；例如，除了药典仪器40目以外的其他规格的溶出篮（例如：10，20或80目），通过充足的数据进行详细的说明后也可以使用.必须注意的是篮网孔径必须是均匀的并且满足<711>规则的尺寸要求.A noncompendial apparatus may have someutility with proper justification, qualification, and documentation ofsuperiority over the standard equipment. For example, a smallvolume apparatuswith mini paddles and baskets may be considered for lowdosage strengthproducts. A rotating bottle or dialysis tubes may have utility for microspheresand implants, peak vessels, and modified flowthrough cells for special dosageforms including powders and stents.非药典溶出仪器具有优于药典尺度仪器的适合设备、资质和文件.例如，一个小体积的溶出仪器配有小桨或小篮可以用于低剂量制剂.旋转瓶或透析管可能适用于微球、植入制剂，改良的流通池适用于特殊剂型包含粉末和支架.2. METHODDEVELOPMENT2. 办法的开发A properly designed test should yielddata that are not highly variable, and should be free of significant stabilityproblems.High variability in the results can make it difficult to identifytrends or effects of formulation changes. Sample size can affect the observedvariability. One guidance defines dissolution results as highly variable if therelative standard deviation (RSD) is more than 20% at time points of 10 min orless and more than 10% at later time points for a sample size of 12 (14).However,during method development, smaller sample sizes may be used, and theanalyst will need to make a judgment accordingly.Most dissolution results,however, exhibit less variability. In the development of a dissolutionprocedure the source of the variability should be investigated, and attemptsshould be made to reduce variability whenever possible. The two most likelycauses are the formulation itself (e.g., drug substance, excipients, ormanufacturing process) or artifacts associated with the test procedure (e.g.,coning, tablets sticking to the vessel wall or basket screen). Visualobservations are often helpful for understanding the source of the variabilityand whether the dissolution test itself is contributing to the variability. Anytime the dosagecontents do not disperse freely throughout the vessel in auniform fashion, aberrant results canoccur. Depending on the problem, theusual remedies include changing any of the following factors: the apparatustype, speed of agitation, level of deaeration,sinker type, or composition ofthe medium.公道设计一个试验包管数据稳定性（即较低的变异性），并且能够明显反应出样品稳定性问题.结果的高变异难以确定处方变更的趋势和处方变更对溶出度结果的影响.样本大小影响所不雅察到的变异性.如果在10分钟 12个样本的相对尺度偏差（RSD）不得过20%或后续取样点的RSD值大于10%.，指导原则对溶出度试验结果定义为高变异性.然而，在办法开发进程中，可以使用较小的样本量，需要对阐发作出相应的判断.大多数溶出结果，表示出较少的变异性.在溶出度试验开发进程中应对产生变异的原因进行研究，只要有可能，应测验考试削减变异性.引起变异性的两个最可能的原因是制剂自己（例如，原料药，辅料，或制剂工艺）和与检测进程相关的处理进程（例如，溶出漩涡，片粘在溶出杯壁或篮网上）.试验进程的不雅察往往有助于查找产生变异的原因或溶出度测定办法自己是否会产生变异性.任什么时候间内剂量含量不克不及均匀地分离在整个容器中，异常结果就可能产生.按照不合的问题，通常的调节办法包含下列任何一个因素的改动：仪器，转速，脱气程度，沉降篮类型，或溶出介质的组成.。
23/02/10Lecture 5 ConcentrationEvaporation• • • For any liquid, the individual molecules within the liquid are continuously in motion A small percentage of these molecules attain enough kinetic energy to leave the liquid phase This exerts an opposing pressure on the atmosphere above the solution known as the vapor pressure, PAtmospheric pressure, PatmVapor Pressure, P123/02/104. When enough energy, in the form of heat, is imparted to the solution the vapor pressure becomes equal to the atmospheric pressure and the liquid begins to boilP < PatmP ≥ PatmCrystallization223/02/10What you need• Pure Protein– Native PAGE – SDS PAGE – N-terminal sequencing - IEF - Mass Spec• Stable for a reasonable period of time– Dependent on stabilization buffer, 4°C vs Room temperture• Concentrated– Need a concentration that will precipitateCrystallization• Once the metabolite has been extracted, it can be further concentrated and purified by crystallisation, either by evaporation or by transfer to lower temperature (gentle way) • Crystallisation refers to the formation of solid crystals from a homogenous solution • Like ice, crystals are physically homogenous solids. • Crystals exhibit a high degree of internal three dimensional order and a definite. • High degree of internal order means that the array of atoms, ions, molecules, or molecule assemblies is ordered over many atomic dimensions. • Is a solid-liquid separation technique, may be achieved by evaporation, low temperature treatment or addition of chemical reactive with the solute323/02/10• If more molecules are added to the solution, the system undergoes internal changes until the point is reached where there is insufficient solvent to maintain full hydration of the molecules. • Under these conditions (the so-called supersaturated state) the system is no longer at equilibrium. • Therefore, it will be thermodynamically driven toward a new equilibrium state with a corresponding new free energy minimum. • Crystallisation is known to lower the free energy of proteins by approximately 3-6 kcal/mole relative to the dissolved state in solution. • This aggregation results in partitioning of the molecules between soluble and solid phases • The solid phase can appear in a state of either amorphous precipitate of crystal nucleiWhat can happened to a supersaturated solution?423/02/10523/02/10How to grow well ordered crystals?•• •The optimal conditions would have to begin with the formation of a preferably single nucleus in the nucleation zone just beyond the metastable zone. As the crystal grow, the solution would return to the metastable region and no more nuclei could occur. The remaining nuclei would grow, at a decreasing rate that would help to avoid defect formation until equilibrium is reachedHow to reach the nucleation zone623/02/10Theory of Crystallization IIIncreasing precipitant concentrationprecipitantCrystalline? solubleIncreasing protein concentrationTypes of crystallization setupsHanging dropCover slip(attached with grease)Sitting DropDrop(Protein/precipitant mix)Clear tapeWell(precipitant)723/02/10What’s in the “well.”• “Precipitant”– Buffers• Screens usually contain 100 mM Buffer pH 4.5-9– Salts• Huge variety here, usually at 200 mM in screens– Precipitants• Poly Ethylene Glycols (PEGS)– 10-30% – MW 400 to 10,000 with very different results• Salts (AmSO4, LiCl, NaFormate, NaCitrate @ 1-3M) • Ethanol, MPD, iso-propanolChemical precipitants• Chemical precipitants are the most widely used agents for achieving supersaturation of macromolecules in order to induce crystallisation. • The influence of these compounds is mainly on the solvent, eg bulk water rather than on the solute. • Commonly used precipitants can be divided into several main categories: salt, high molecular weight straight chain polymers (eg: polyethylene glycol) and organic solvents (2-methyl 2, 4-pentaediol)823/02/10Theory of Crystallization• The protein is mixed with a crystallization solution containing various precipitants. (usually 2µl and 2µl) (called the drop) • The diluted protein and crystallization mixture is incubated “over” the concentrated crystallization solution (called the well). • Over time, the drop will equilibrate with the well concentrating both the protein and the precipitants. • As the protein concentrates it can come out of solution as either a precipitate, a phase transition (oil), or as a crystal.General techniques: Vapor diffusion923/02/10Vapor diffusion and the phase diagramFactors may affect crystallisation1. Purity- for sufficient homogeneity, the bioproduct usually be at least 97% pure 2. pH- different pH can result in different packing orientations. Buffers such as Tris-HCl, are often necessary for the maintenance of a particular pH 3. concentration of bioproducts, 4. Temperature (either at 4c or 18-22c). By lowering the T, you can reduce the solubility of the ions. 5. Precipitants- eg ammonium sulfate or polyethylene glycol (PEG) are compounds that cause the protein to precipitate out of solution10Good vs bad crystalSolubility of β-lactoglobin as a function of pH at severalNaCl concentrations•Solubility and pI;minimum ofsolubility at pI; pI isdependent on theconcentration of salt.Low solubility at pI isdue to lack ofrepulsion of charges.-These solutions are withdrawn from their respective compartmentsto achieve useful changes in the elctrolyte content of solutions without substantially affecting the content of nonelectolytes (example; desalting of protein solutions or whey)Osmosis•Water will typically be present on both sides of the membrane, with each side having a different concentration of dissolved minerals.•Since the water with the less concentrated solution seeks to dilute the more concentrated solution, water will pass through the membrane from the lower concentration side to the greater concentration side. •Eventually, osmotic pressure (seen in the diagram below as the pressure created by the difference in water levels) will counter the diffusion process exactly, and an equilibrium will form.other water molecules to pass through while excluding other substances.RO MembraneProduct WaterSpiral Wound Membrane ElementSeveral layers of membrane material are sandwiched between spacer material to form leaves with a feed / reject channel and a product channel. These leaves are then rolled around a central product collection tube. This assembly is referred to as a spiral wound membrane element.。
