科技 SCIENCE & TECHNOLOGY 在这部分，你的任务是： 一，背诵话题词汇短语 二，为题目列出英文提纲 基础词汇短语 advanced science 尖端科学 scientific invention 科学发明 exert a far-reaching impact on…对…产生一种深远的影响 double-edged sword 双刃剑 earth-shaking changes 翻天覆地的改变 pay the way for the future development 为未来的发展铺平道路 lay a solid foundation for…为…打下良好的基础 energy crisis 能源危机 depletion of resources 能源消耗 milestone 里程碑 sophisticated equipment 尖端设备 technical innovation 科技创新 expediency 权宜之计 antithetical 与…背道而驰的 over-commercialized 过渡商业化的 a heated discussion 热烈的讨论 exhaust gas 废气 disastrous 灾难性的 overshadow 使…相形见绌 compared to/with…与…相比 usher in 引领 speedy and comfortable 既快捷又舒适 opposite forces 负面影响 a fatal breakdown 致命故障 potential hazards 潜在危险 pose a threat to…对…有一种威胁 promote relative industries 促进相关产业发展 accelerate 加速… means of transportation 交通方式 transportation tools 交通工具 social status 社会地位 environmentally-friendly resources 环保的能源 make people's life easier 使人们生活更方便 alternative fuel 可替代燃料
英语演讲稿：未来的工作 这篇《英语演讲稿范文：未来的工作》，是特地，希望对大家有所帮助！ 热门演讲推荐：竞聘演讲稿 | 国旗下演讲稿 | 英语演讲稿 | 师德师风演讲稿 | 年会主持词 | 领导致辞 everybody good afternoon:. first of all thank the teacher gave me a story in my own future ideal job. everyone has a dream job. my dream is to bee a boss, own a pany. in order to achieve my dreams, i need to find a good job, to accumulate some experience and wealth, it is the necessary things of course, in the school good achievement and rich knowledge is also very important. good achievement and rich experience can let me work to make the right choice, have more opportunities and achievements. at the same time, munication is very important, because it determines whether my pany has a good future development. so i need to exercise their municative ability. i need to use all of the free time to learn
关于科技的英语演讲稿—Technologyand thepresenceofstudents,ladiesandteachers,everyone!iw aspreparedintervalsofcloudtoday,inhonorhereentitled“te chnologyandfuture”speech,iamveryproudofboth,butsomeune ase.inrecentyears,wehaveseenourgreatmotherland,thecause oftherapiddevelopmentoftechnology,whichallowmetoachines eifeelveryproud.rememberthatlongago,cellphoneusealmostt heonlyone,whichiscalled,butafewyearsago,cellphoneshasun dergonegreatchanges,notonlylookmorebeautiful,butalsouse more,youcanusethephonestotakepictures,meetings,internet ,textmessages,etc.aseriesofthingsthatitheirlifemoreconv enient,soiammoreawareofthestrengthofthetechnology,butia mjustafledglingsstudents,“technology”asthewordalsoawa reofthelimited,iamunabletousesomeverydifficulttheorytoe laboratetechnologyxuanji,norighttoworkontheireldersican promiseofthetechnologyblueprint.butiamwillingtouseastud ent’sperspectivetotheimaginetechnologyandthefuture.fromgene ticengineering“isaliveprinces”dream,nano-technology“
Technology & media 类 科技类 People today can perform the everyday tasks such as shopping, banking or even business transactions, without meeting others face-to-face. What effects will this phenomenon have on individuals and society as a whole? 开头段（不少于3+1句） The interactivity of the Internet and the mobile phone has enabled a multitude of people to purchase their desired items or pay their phone bills without stepping out of their offices or homes. And many others can even register for tests or sign contracts online. This sweeping trend of going about everyday business in the virtual world has triggered a marked decline in face-to-face contact between people. Thus, it is essential that we identify the implication of this trend on both individuals and society as a whole. 主体段1（不少于1+6句） The impact of this phenomenon on individuals is profound. First, Individual efficiency in business transaction and banking will be greatly enhanced. And those who dread shopping are spared the chore of browsing around in shops. Secondly, the increasingly sedentary lifestyle will engender a higher incidence of ailment. More overweight people means more patients suffering from cardiovascular diseases such as vein hardening, diabetes and hypertension. Thirdly, the absence of face-to-face contact may induce distrust between business partners. An inherent sense of disbelief is apt to ruin a telecommunicated negotiation when negotiators can only see videos of each other transmitted via the Internet. 主体段2（不少于1+6句） This trend also has widespread repercussions on society as a whole. In the first place, the burgeoning e-commerce will, doubtless, boost corporate efficiency immeasurably. And higher efficiency means more earnings and less costs for businesses. In the second place, online fraud, be it banking or trading, retail or wholesale, is sure to abound in the cyberspace. We must search for practicable and effectual means of curbing it. In the third place, the proliferation of e-commerce may exacerbate man's overdependence on technology. And that can render our lives unspontaneous and our tempo of life too fast and furious. 结尾段（不少于2句）
关于坚持的英语演讲稿 Results are not important, but they can persist for many years as a commemoration of. Many years ago, as a result of habits and overeating formed one of obesity, as well as indicators of overall physical disorders, so that affects my work and life. In friends to encourage and supervise, the participated in the team Now considered to have been more than three years, neither the fine rain, regardless of winter heat, a day out with 5:00 time. The beginning, have been discouraged, suffering, and disappointment, but in the end of the urging of friends, to re-get up, stand on the playground. 成绩并不重要，但可以作为坚持多年晨跑的一个纪念。多年前，由于庸懒习惯和暴饮暴食，形成了一身的肥胖，以及体检指标的全盘失常，以致于影响到了我的工作和生活。在好友的鼓励和督促下，参加了晨跑队伍。现在算来，已经三年多了，无论天晴下雨，不管寒冬酷暑，每天五点准时起来出门晨跑。开始时，也曾气馁过、痛苦过、失望过，但最后都在好友们的催促下，重新爬起来，站到了操场上。 In fact, I did not build big, nor strong muscles, not a sport-born people. Over the past few years to adhere to it, because I have a team behind, the strength of a strongteam here, very grateful to our team, for a long time, we encourage each other, and with sweat, enjoying common health happy. For example, Friends of the several run in order to maintain order and unable to attend the 10，000 meters race, and they are always concerned about the brothers and promptly inform the place and time, gives us confidence and courage. At the same time, also came on their own inner desire and pursuit for a good health, who wrote many of their own log in order to refuel for their own, and inspiring. 其实我没有高大身材，也没健壮肌肉，天生不属于运动型的人。几年来能够坚持下来，因为我的背后有一个团队，有着强大团队的力量，在这里，非常感谢我们的晨跑队，长期以来，我们相互鼓励着，一起流汗，共同享受着健康带来的快
电力电子技术课程设计报告 题目高频开关稳压电源 专业电气工程及其自动化 班级 学号 学生姓名 指导教师 2016年春季学期 起止时间：2016年6月25日至2016年6月27日
设计任务书11 高频开关稳压电源设计√ 一、设计任务 根据电源参数要求设计一个高频直流开关稳压电源。 二、设计条件与指标 1.电源：电压额定值220±10%，频率：50Hz； 2. 输出:稳压电源功率Po=1000W,电压Uo=50V； 开关频率:100KHz 3.电源输出保持时间td=10ms(电压从280V下降到250V)； 三、设计要求 1.分析题目要求，提出2~3种电路结构，比较并确定主电路 结构和控制方案； 2.设计主电路原理图、触发电路的原理框图，并设置必要的 保护电路； 3.参数计算，选择主电路及保护电路元件参数； 4.利用PSPICE、PSIM或MATLAB等进行电路仿真优化； 5.撰写课程设计报告。 四、参考文献 1.王兆安，《电力电子技术》，机械工业出版社； 2.林渭勋等，《电力电子设备设计和应用手册》； 3.张占松、蔡宣三，《开关电源的原理与设计》，电子工业 出版社。
目录 一、总体设计 (1) 1．主电路的选型（方案设计） (1) 2.控制电路设计 (4) 3.总体实现框架 (4) 二、主要参数及电路设计 (5) 1.主电路参数设计 (5) 2.控制电路参数设计 (7) 3.保护电路的设计以及参数整定 (8) 4.过压和欠压保护 (8) 三、仿真验证（设计测试方案、存在的问题及解决方法） (9) 1、主电路测试 (9) 2、驱动电路测试 (10) 3、保护电路测试 (10) 四、小结 (11) 参考文献 (11)
关于工作的优秀英语演讲稿 Different people have various ambitions. Some want to be engineers or doctors in the future. Some want to be scientists or businessmen. Still some wish to be teachers or lawers when they grow up in the days to come. Unlike other people, I prefer to be a farmer. However, it is not easy to be a farmer for Iwill be looked upon by others. Anyway,what I am trying to do is to make great contributions to agriculture. It is well known that farming is the basic of the country. Above all, farming is not only a challenge but also a good opportunity for the young. We can also make a big profit by growing vegetables and food in a scientific way. Besides we can apply what we have learned in school to farming. Thus our countryside will become more and more properous. I believe that any man with knowledge can do whatever they can so long as this job can meet his or her interest. All the working position can provide him with a good chance to become a talent. 1 ————来源网络整理，仅供供参考
高频开关电源技术规范书 2011年主网技改工程 通讯系统电源 (高频开关电源、免维护电池) 技术规范书 1、概述 1.1本技术规范书仅适用于2011主网技改工程。 1.2本规范未对一切技术细节做出规定，也未充分引述有关标准和规范，卖方应提供符合本规范书和遵照国际电工委员会标准(IEC)、国际公制(SI)及国家标准的符合国家电力行业标准的优质产品。技术指标应符合YD/T731《通讯用高频开关整流器》的规定。 1. 3本规范未尽事宜，双方协商解决。 2、主要技术要求 2.1 供货数量: 序号名称规格及型号单位数量备注 1 高频开关电源屏 - 48V/120A(4*30A) 面 4 2 蓄电池屏 48V/300AH，每组24只，-2V 面 8 3 电池巡检仪每套可接48只电池套 4 高频开关电源:-48V/120A (4*30A) 4套 蓄电池: -48V/300AH 4组(包括电池柜) 每套两组每组24只，2V/只 2. 2设备电气性能 3. 单套高频开关电源配置: 1) 具备交流输入配电单元、整流单元、直流输出配电单元、监控单元，并为一体化机
柜，应能至少接入2组蓄电池。 2) 具备完善的故障告警、保护功能(交流输入故障、直流输出故障、整流单元故障、 监控单元故障等自动保护功能)，且部分状态具有自动恢复功能(交流过压、欠压、 直流过流、过温)。 3) 交流配电单元: 输入2路，输入电压:三相五线制:380V?20%,50?10%HZ，2路交流输入电源能自动切换，且互为主备用。 输出:三相输出分路(2路):2路32A，2路25A 单相输出分路(14路):2路20A，8路10A，4路6A。 4) 直流配电单元: 输入:整流4路:48V/4*30A,可调整为(10A-20A-30A-60A，最大能达到120A。 第 2 页共 8页 蓄电池: -48V?300AH 蓄电池保护值:43V?1% 输出电压:-48V(-40V,-58V)输出总容量为120A。输出电流规格:40A 6路、20A 40路、10A 14路直流输出采用端子接线。 5) 整流模块单元: 整流模块采用N+1方式工作 由多个整流模块组成的整流单元，当其中一个(或几个)模块故障时，不得造成整个 系统停止工作。 输入电压:304,456V(45,66HZ)
雅思考试大作文范文四篇科技类 网为考生们提供最新最全的雅思写作范文,希望对大家有帮助。 雅思大作文范文：电脑VS老师 It is witnessed that computer technology hasbrought human beings uncountable benefits and aneducational revolution seemingly can be expected hence a substitution of teachers in theclassroom. As to discuss this controversial issue, opinions vary from person to person. On the one hand, the teacher plays an important role as a supervisor as well as aconductor in the classroom (topic sentence).It is commonly believed that adolescents are tooyoung to distinguish the good from the bad and they need correct guidance from decentadults; otherwise, they might stray from the right way. Children are always easy to becomeaddicted to computer games, which have too much violent and pornographic propaganda.Without teachers' guidance, most children would spend hours playing fascinating games oncomputers instead of studying useful knowledge during school times. Moreover, a teacher in theclassroom may organize a discussion on a complicated or
关于工作的英语演讲稿 【篇一：关于工作的英语演讲稿】 关于工作的英语演讲稿 different people have various ambitions. some want to be engineers or doctors in the future. some want to be scientists or businessmen. still some wish to be teachers or lawers when they grow up in the days to come. unlike other people, i prefer to be a farmer. however, it is not easy to be a farmer for iwill be looked upon by others. anyway,what i am trying to do is to make great contributions to agriculture. it is well known that farming is the basic of the country. above all, farming is not only a challenge but also a good opportunity for the young. we can also make a big profit by growing vegetables and food in a scientific way. besides we can apply what we have learned in school to farming. thus our countryside will become more and more properous. i believe that any man with knowledge can do whatever they can so long as this job can meet his or her interest. all the working position can provide him with a good chance to become a talent. 【篇二：关于责任感的英语演讲稿】 im grateful that ive been given this opportunity to stand here as a spokesman. facing all of you on the stage, i have the exciting feeling of participating in this speech competition. the topic today is what we cannot afford to lose. if you ask me this question, i must tell you that i think the answer is a word---- responsibility. in my elementary years, there was a little girl in the class who worked very hard, however she could never do satisfactorily in her lessons. the teacher asked me to help her, and it was obvious that she expected a lot from me. but as a young boy, i was so restless and thoughtless, i always tried to get more time to play and enjoy myself. so she was always slighted over by me. one day before the final exam, she came up to me and said, could you please explain this to me? i can not understand it. i
通讯系统电源 （高频开关电源、免维护电池）技术规范书
1、概述 1.1本技术规范书仅适用于2011主网技改工程。 1.2本规范未对一切技术细节做出规定，也未充分引述有关标准和规范，卖方应提供符 合本规范书和遵照国际电工委员会标准（IEC）、国际公制（SI）及国家标准的符合国家电力行业标准的优质产品。技术指标应符合YD/T731《通讯用高频开关整流器》的规定。 1.3本规范未尽事宜，双方协商解决。 2、主要技术要求 2.1 供货数量： 序号名称规格及型号单位数量备注 1 高频开关电源屏-48V/120A（4*30A）面 4 2 蓄电池屏48V/300AH，每组24只，-2V 面8 3 电池巡检仪每套可接48只电池套 4 高频开关电源：-48V/120A （4*30A） 4套 蓄电池： -48V/300AH 4组（包括电池柜） 每套两组每组24只，2V/只 2.2设备电气性能 3.单套高频开关电源配置： 1)具备交流输入配电单元、整流单元、直流输出配电单元、监控单元，并为一体化机 柜，应能至少接入2组蓄电池。 2)具备完善的故障告警、保护功能（交流输入故障、直流输出故障、整流单元故障、 监控单元故障等自动保护功能），且部分状态具有自动恢复功能（交流过压、欠压、直流过流、过温）。 3)交流配电单元： 输入2路，输入电压：三相五线制：380V±20%,50±10%HZ，2路交流输入电源能自动切换，且互为主备用。 输出：三相输出分路（2路）：2路32A，2路25A 单相输出分路（14路）：2路20A，8路10A，4路6A。 4)直流配电单元： 输入：整流4路：48V/4*30A,可调整为(10A-20A-30A-60A，最大能达到120A。
2018-06-02: Task 2 (India) Some people use technology to take advice for their medical problems rather than seeing to doctor. Why is this so? Is it positive or negative development according to you? 范文1： Owing to technology, everything becomes easily accessible. Some people take advantage of technology as they discuss their health issues with experts on the internet rather than going to them. This trend increasing in our society as people have a busy schedule. In my opinion, it is a positive development as taking medical prescription online save time as well as energy. But it has some disadvantages also so discussed below. Technology brings people close enough that they can discuss their problems with a number of people at once and can share their experiences so that others can take advantage of this. Taking online prescription save time, as there is no need to run to the hospitals and set a queue to meet the doctors. Using technology, people can take advice from foreign experts rather than considering only native ones. Various online websites are now available, where experts and people can communicate with each other, here https://www.doczj.com/doc/d53612053.html, is worth mentioning as it provides a common platform for everyone. However, it may have some disadvantages, as in serious health issues such as cancer or in other deadly diseases where the doctor can visually check and do some tests, is not possible online. In those cases, people should visit the experts and get proper medical care. Under specialist vision, the patient gets recover much faster. Although technology provides us various advantages, sometimes under certain circumstances, it may worsen the situation. For example, in case of heart attack patient should rush to the hospital rather than taking online medical care. In some medical issues such as cold, fever people should take advice online but in other deadly cases, people should visit to doctors so that can take better medication. In conclusion, no doubt technology has a huge role and brings everything closer, it has its own merits and demerits, we can take only certain medication and healthcare pieces of advice such as what we should eat to reduce the weight, not in other serious issues. 范文2： Many individuals are making use of technology such as the internet to seek medical advice instead of visiting a doctor. There are many reasons behind this, however, in my opinion, it is a negative development.
关于人英语演讲稿(精选多篇) 关于人的优美句子 1、“黑皮小子”是我对在公交车上偶遇两次的一个男孩的称呼代号。一听这个外号，你也定会知道他极黑了。他的脸总是黑黑的；裸露在短袖外的胳膊也是黑黑的；就连两只有厚厚耳垂的耳朵也那么黑黑的，时不时像黑色的猎犬竖起来倾听着什么；黑黑的扁鼻子时不时地深呼吸着，像是在警觉地嗅着什么异样的味道。 2、我不知道，如何诠释我的母亲，因为母亲淡淡的生活中却常常跳动着不一样的间最无私、最伟大、最崇高的爱，莫过于母爱。无私，因为她的爱只有付出，无需回报；伟大，因为她的爱寓于
普通、平凡和简单之中；崇高，是因为她的爱是用生命化作乳汁，哺育着我，使我的生命得以延续，得以蓬勃，得以灿烂。 3、我的左撇子伙伴是用左手写字的，就像我们的右手一样挥洒自如。在日常生活中，曾见过用左手拿筷子的，也有像超级林丹用左手打羽毛球的，但很少碰见用左手写字的。中国汉字笔画笔顺是左起右收，适合用右手写字。但我的左撇子伙伴写字是右起左收的，像鸡爪一样迈出田字格，左看右看，上看下看，每一个字都很难看。平时考试时间终了，他总是做不完试卷。于是老师就跟家长商量，决定让他左改右写。经过老师引导，家长配合，他自己刻苦练字，考试能够提前完成了。现在他的字像他本人一样阳光、帅气。 4、老师，他们是辛勤的园丁，帮助着那些幼苗茁壮成长。他们不怕辛苦地给我们改厚厚一叠的作业，给我们上课。一步一步一点一点地给我们知识。虽然
他们有时也会批评一些人，但是他们的批评是对我们有帮助的，我们也要理解他们。那些学习差的同学，老师会逐一地耐心教导，使他们的学习突飞猛进。使他们的耐心教导培养出了一批批优秀的人才。他们不怕辛苦、不怕劳累地教育着我们这些幼苗，难道不是美吗？ 5、我有一个表妹，还不到十岁，她那圆圆的小脸蛋儿，粉白中透着粉红，她的头发很浓密，而且好像马鬓毛一样的粗硬，但还是保留着孩子一样的蓬乱的美，卷曲的环绕着她那小小的耳朵。说起她，她可是一个古灵精怪的小女孩。 6、黑皮小子是一个善良的人，他要跟所有见过的人成为最好的朋友！这样人人都是他的好朋友，那么人人都是好友一样坦诚、关爱相交，这样人与人自然会和谐起来，少了许多争执了。 7、有人说，老师是土壤，把知识化作养分，传授给祖国的花朵，让他们茁壮成长。亦有人说，老师是一座知识的桥梁，把我们带进奇妙的科学世界，让
网络教育学院《电源技术》课程设计 题目：高频开关电源的干扰及抑制 学习中心： 层次： 专业： 年级： 学号： 学生：程剑 指导教师： 完成日期：年月日
目录 设计简介及要求 (1) 1 高频开关电源的干扰原理分析 (1) 1.1 高频开关电源工作原理 (1) 1.2 高频开关电源干扰的来源 (2) 1.3 高频开关电源干扰的存在形式及危害 (2) 2 高频开关电源干扰的抑制技术 (2) 2.1 滤波技术 (2) 2.2 屏蔽技术 (3) 2.3 软开关技术 (3) 2.4 扩频调制技术 (3) 2.5 PCB 设计技术 (3) 2.6 接地技术 (3) 3 高频开关电源及滤波器设计 (3) 3.1 高频开关电源设计要求 (3) 3.2 高频开关电源设计方案 (3) 3.3 电源滤波器设计 (3) 3.3.1 EMI滤波器的基本形式 (4) 3.3.2 EMI滤波器的设计原则 (4) 3 总结 (4)
设计简介及要求 现代社会中，人类生活的各个方面都离不开电子设备的发展。电子设备大多数都依赖于开关电源来提供稳定的电力供应。开关电源以其高效率、低损耗、小体积等特点，近年来快速发展，在通信设备、医疗设备以及信息处理设备等不同领域中广泛应用，取得了巨大成就。由于开关电源工作在高频开关状态，内部会产生很高的电流、电压变化率(即高dv/dt和di/dt)，导致开关电源产生较强的电磁干扰(EMI)。在有限的空间及频谱资源条件下，随着电子设备密集程度不断增加，空间的电磁环境越来越复杂。为了适应对电子产品电磁兼容性能指标的高要求，需要对电磁兼容采取重视;同时，要研究开发电磁兼容新技术，采取有效的防护措施。所以，对于开关电源来说，电磁兼容问题的研究是十分必要的。EMI信号既具有很宽的频率范围，又有一定的幅度，它不仅对电网造成污染，直接影响到其他用电设备的正常工作，而且作为辐射干扰闯人空间，对空间也造成电磁污染。目前，抑制开关电源的EMI提高开关电源的质量使之符合EMC标准已成为开关电源设计者越来越关注的问题。 本次设计就此问题展开分析，主要要求有以下几点： （1）围绕开关电源的工作原理，分析开关电源工作过程中产生电磁干扰的原因及抑制措施。 （2）介绍开关电源的基本原理、干扰来源及抑制措施。 （3）分析开关电源产生电磁辐射干扰的原因及造成的危害。 （4）论述开关电源电磁干扰的抑制方法。 1 高频开关电源的干扰原理分析 由于开关电源具有效率高、容易实现小型化的优点，所以目前被广泛应用在电子设备中。但是开关电源本身就是噪声源，在工作时会产生干扰，这就需要采取措施对其产生的噪声进行抑制。目前开关电源的体积不断追求小型化，开关频率也随之提高，导致噪声不断增加。要保证开关电源设备的正常工作，就需要对噪声的抑制加以重视。 1.1 高频开关电源工作原理 开关电源将市电直接整流滤波成为直流高压，然后通过逆变器转换成低压的高频交流电压，再经过二次整流和滤波变成所需要的直流低电压。考虑到目前大量应用的开关电源都是采取AC/DC-DC/DC级联的形式，因此，图1所示的开关电源结构具有较强的代表性。
关于科技的英语演讲稿—Technology 目录 第一篇：英语演讲稿—Technology and future 第二篇：英文科技转让协议范本Technology assignment agreement 第三篇：关于科技的英语演讲稿—Technologyandfuture 第四篇：演讲稿 modren Technology or traditional value 第五篇：what Technology brought us 科技给我们带来的影响正文 第一篇：英语演讲稿—Technology and future the presence of students, ladies and teachers： everyone! i was prepared intervals of cloud today, in honor here entitled Technology and future speech, i am very proud of both, but some unease. in recent years, we have seen our great motherland, the cause of the rapid development of Technology, which allow me to a chinese i feel very proud. remember that long ago, cell phone use almost the only one, which is called, but a few years ago, cell phones has undergone great changes, not only look more beautiful, but also use more, you can use the phones to take pictures, meetings, internet, text messages, etc.