200501-science-A generalized approach to the modification of solid surfaces(1)

0254-6124/2021 /41(3)-439-06Chin. J. Space Sci.空间科学学报Z H A N G Shenyi, H O U Donghui, W I M M E R-S C H W E I N G R U B E R R F, S U N Yueqiang, W A N G Chunqin, C H A N G Zheng, X U Zigong. S H E N Guohong, Y U A N Bin, X U E Changbin. Radiation dose of L N D on the lunar surface in two years (in Chinese). Chin. J. Space Sci.,2021, 41(3): 439-444. DOI: 10.11728/cjss2021.03.439L N D两年月表辐射剂量测量结果+张珅毅 i’2’3’4侯东辉 l2’3’4WIMMER-SCHWEINGRUBER R F 1,5孙越强W’3王春琴W’3常峥1’2’3徐子贡5沈国红以3袁斌1，2’3薛长斌11(中国科学院国家空间科学中心北京100190)2(天基空间环境探测北京市重点实验室北京100190)3(中国科学院空间态势感知重点实验室北京100190)4(中国科学院大学北京100049)5(德国基尔大学实验应用物理研究所基尔24118)子商要月球表面的辐射剂量是影响航天员安全和月表驻留时间的重要参数，通过对月表的粒子辐射测量可以为 航天员的辐射安全防护提供重要依据.利用嫦娥四号着陆器上搭载的月表中子与辐射剂量探测仪二年的观测数据得 到：月表粒子辐射在硅中的平均总吸收剂量率为U.e e i C U S/i G y.h-1,中性粒子吸收剂量率为2.67士0.16/xGy.h-1.辐射剂ti：率随时间出现缓慢的下降，L E T谱的变化则很小.同时观测到了2020年12月太阳活动末期由于银河宇 宙线福布斯K降导致的辐射剂量率降低.关键词嫦娥四号，月表，辐射剂量，航天员中图分类号V 478R a d ia tio n D ose o f L N D on th e L u n a rS urface in T w o Y earsZHANG Shenyi1，2,3,4HOU Donghui1，2,3,4WIMMER-SCHWEINGRUBER R F1-5 SUN Yueqiang1’2’3WANG Chunqin12-3CHANG Zheng1’2’3XU Zigong5SHEN Guohong1’2,3YUAN Bin1，2,3XUE Changbin1l(National Space Science Center, Chinese Academy of Sciences, Beijing100190)2(Beijing Key Laboratory of Space Environment Exploration, Beijing100190)3(Key Laboratory of Environmental Space Situation Awareness Technology, Beijing100190)4( University of Chinese Academy of Sciences, Beijing100049)^(Institute of Experimental and Applied Physics, Christian-Albrechts-University, Kiel24118) **国家自然科学基金项目资助（41941001，D020104)2021-04-16收到原稿，2021-05-03收到修定稿E-mail:***********.cn440Chin. J. Space Sci.空间科学学报 2021, 41(3)Abstract T h e radiation d o s e o n the lunar surface is a n i m p o r t a n t p a r a m e t e r affecting the safety of astronauts a n d the residence t i m e of the lunar surface. T h e m e a s u r e m e n t of t he particle ra­diation o n the lunar surface c a n provide a n i m p o r t a n t basis for the radiation safety protection of astronauts. B a s e d o n the two-y ea r observation d a t a of lunar n e u t r o n a n d radiation dos e detector o n C h a n g1E-4 lander, the aver a g e total a b s o r b e d dose rate of lunar particle radiation in silicon is12.66士0.45/i G y.h-1, a n d the a b s o r b e d dose rate of neutral particle is 2.67士0.16/i Gy.h-1.T h e ra­diation do s e rate decreases slowly w i t h time, b u t the c h a n g e of L E T s p e c t r u m is very small. T h e decrease of radiation dose rate d u e to the decrease of f ubusch of G C R at the e n d of solar activity inD e c e m b e r 2020 w a s observed.Key words C h a n g,E-4, L u n a r surface, R a d iation dose, A s t r o n a u t〇引言随着中国嫦娥四号/五号任务的圆满成功，月球 科研站及月球基地等月球探测步伐也正在逐步开展，最终实现人类月球深空的长期驻留.空间辐射暴露 是影响航天员健康的主要风险之一 [1_31，因为长期 暴露在银河宇宙射线中可能引起航天员一系列缓发 的健康问题，例如白内障、癌症以及中枢神经系统或 其他器官系统+5i的退化性疾病.月球表面的粒子辐射来源主要有三种:一是长期 存在银河宇宙线（G C R)%G C R受到行星际磁场的 调制发生缓慢的变化；二是偶发的太阳高能粒子事 件，太阳发生耀斑及日冕物质抛射时会发出大量的 高能粒子，在较短的时间内对月球表面产生强烈的辐 射A三是S E P s和G C R通过与月壤的作用产生的 二次粒子，主要是中子和7射线[8].嫦娥四号着陆器在2019年1月3日02:26 U T登陆月球背面的冯卡门陨石坑.在此之前，尚未对月 球表面的辐射剂量率进行过主动测量（即时间分辨).在阿波罗任务期间，航天员到达月球时虽然随身携带 了剂量仪，但是在月球表面的时间段内的辐射数据从 未进行过报告为了评估辐射暴露，必须利用探测器系统测量 相关量.吸收剂童D是沉积在探测器中的能量五 (单位：k e V)与探测器质量（m)的比值，常用的单 位为格瑞（G y z^k f1).将吸收剂量除以累积的时 间可以得到剂量率（单位：G y h-1).利用两个探测 器符合的逻辑工作方式以及其中一个探测器中的沉 积能量分布，可以获得线性能量转移谱L E T (单位: k e V./m T1).由于人体不是由硅构成的，为了便于比较不同测董的剂量、剂量率以及L E T谱，通常使 用1.301U1的恒定剂量转换系数.将硅中的测量值转 换为在水中相应的物理量.嫦娥四号任务在2019年1月登陆月球背面后, 目前已持续在轨工作超过25个月昼，月表中子与辐 射剂量探测仪（L u n a r L a n d e r N e u t r o n s a n d D o s i m e­t r y,L N D)112，131 对月表的粒子辐射环境和辐射剂量 进行测量，包括质子、电子、重离子能谱，带电粒子 和中性粒子的辐射剂量以及L E T谱[141.L N D安装在嫦娥四号着陆器的有效载荷舱内，由10片双灵敏区硅固体探测器（S S D)组成，这10 片硅探测器命名为A-J.总吸收剂量和剂量率通过探 测器B测量，中性粒子的吸收剂量和剂量率通过探 测器C的内灵敏区C1测量，紧密靠近的探测器B和D以及探测器C的外灵敏区C2作为反符合用于 区别带电粒子，L E T谱由d£/d:c确定.1数据结果图1给出了 L N D探头在嫦娥四号着陆器的位 置，图1中的红色箭头指向为L N D的探测指向，为 了保护L N D，舱门在寒冷的月夜关闭，在月昼时打开. 图2显示了 L N D在2019年5月至2021年1月两 年时间共21个月昼期间（着陆器未休眠期间）获得 的辐射剂量测量结果.图2(a)为辐射总剂量率，包括 带电粒子和中性粒子（中子、7射线）的贡献;图2(b)为中性粒子的辐射剂量率；图2(c)为带电粒子的辐 射剂量率；图2(d)为穿透高能带电粒子的通董（质 子>34.8M e V,H e >40M e V)，也代表了银河宇宙线 的通量;图2(e)为地面测量到的奥卢中子结果，其也张珅毅等：L N D 两年月表辐射剂量测量结果44114.513.512.511.510.5 3.63.22.82.42.01211109(a )I —T TT I L-'1^ i i i l 1 1 卜i~~l --H-i：Apr.2019(c)(e )Jul.Oct.Jan.2020DateApr.Jul.Oct.Jan.2021图2 L N D 在嫦娥四号测量到的辐射环境随时间演化结果Fig. 2 T e m p o r a l evolution of the radiation environment o n the M o o n as mea s u r e d by L N D o n C h a n g 5E-4代表了宇宙线的变化情况.通过图2可以看到21 个月昼内月球表面的平均辐射剂量率为12.66±O^^G y.h -1 (S i )，等效到人体中的辐射剂量率为16.46/i G y .h -1 (H 20),其中，中性粒子的辐射剂量 率为S .e T i O .i e /i G y .h -1 (S i )，约占总辐射剂量的 21%.从图2可以看到辐射总剂量率和中性粒子辐 射剂量率的变化与穿透粒子的通童有明显的正相关，与空间物理学认知相符.从2020年10月的第21个月昼开始辐射剂量 率出现了缓慢的下降（见图2阴影部分)，这是由于 行星际磁场的变化造成了银河宇宙线的通最降低导 致的，最直接的证据是LN D测量到的同时间段的穿透粒子数M 和奥卢中子数量也出现了降低.图3显示了 LN D在第7, 9, 13, 16. 20月昼期间图1 L N D 探头在嫦娥四号着陆器的位置，红色箭头为视场方向Fig. 1 L N D sensor h ead (whose field of view is indicated by red arrow) is installed inthe C h a n g ’E-4 lander payload c o m p a r t m e n t(l -M >,a 3(l-M>,D 3(l =>»o 3/o sc !) (■L Jn -M r .*-.E 3-_U J l u /H l n 03/(！s =l a /(！s c !)i Q 5U Q L O Q /O o u -i s u 3d2Z1010'210—110°101102L ET (inH 2〇)/(keV ^m-1)103图3在不同月昼得到的L N D 的L E T 谱（已转化为水)Fig. 3 Linear Ene r gy Transfer (L E T ) spectra(converted to L E T in water) me a su r e d during fourdifferent time periods将L N D的测量结果与月船一号（C h a n d r a y a a n -1)上的粒子载荷R A D 0M [16]和月球轨道器（L R O )上的载荷C R a T E R M的测量结果进行比较,结果列于表1.由于C h a n d r a y a a n -1, LR O和嫦娥四号进行的测量是在太阳平静期进行的，可以假设剂量率的差异主 要是由轨道髙度的差异造成的，即月球提供的屏蔽不 同.然而这种简单的解释并不合理，通过将文中的结 果与没有被月球遮挡的部分（立体角）进行比较可以 看出，屏蔽与吸收剂量并不存在相应的比例关系.R A D O M在2008年离月球很远的地方测得的剂量率与2019年在月球表面测得的剂量率不可比. 原因主要有两点：第一，其处在不同的太阳周期.例 如，从2015年开始，美国好奇号上的辐射评估探测 器R A D在火星观测到银河宇宙射线的剂量率增加了 50%.第二，L N D测量的能量范围与RA D O M和获得的L E T谱结果.可以看到在近两年的时间内月表粒子辐射L E T谱的变化很小，这是因为银河宇宙 线的变化很小，更大的变化需要更长期的观测.L N D在轨期间遇到了两次太阳粒子爆发事件,分别为2019年5月6日[15丨和2020年12月1日，2019年5月的太阳质子事件中L N D的9〜21 M e V高能质子通量出现了少量增长，但L N D的辐射剂量率并没有出现明显的变化.这是因为太阳质子事件 爆发等级不高，能够加速质子的通量和能量也较低, 被仪器挡光层和第一片探测器A 阻挡或者降低了能 量，导致了其在B 探测器的剂量测量中所占比例较442小.2020年12月1日的太阳活动中，磁场出现了 明显的变化，k e V量级的粒子增长大约持续了 10天，而M e V量级的高能粒子并没有出现明显变化,LN D在2020年12月9日开机，处于太阳活动的末期，从 图4可以看到此时测量到的辐射剂量出现了一个明 显的下降,这是因为太阳活动造成了行星际磁场的扰 动，该扰动引起了银河宇宙线的福布斯下降导致辐射 剂量降低,该福布斯下降使辐射剂量比正常水平少下 降了约10%左右.2分析讨论Chin . J . Space Sci .空间科学学报 2021,41(3)13 18 23 12 17 22 11 1621 10 15 20 9 1419 8 13 18Aug. 2020 Sept. Oct. Nov. Dec. Jan. 2021Datew^w w w (q _I J S • S 3 • O I T i _l >3e/ s 3p }y E cu图4太阳质子爆发期间辐射剂量的变化情况Fig. 4 D o s e rate me as ur ed in period of S EP张珅毅等：L N D 两年月表辐射剂量测量结果4433110Jan. 20198CRaTERFeb. 2019$16514工112103 5 7 9 11 312 4 6 8 10Jan. 2019Feb. 2019图5 L N D 和C R a T E R 的剂量率测M. C R a T E R 测量到的剂量率已对月球提供的几何屏蔽进行了修正.垂直线标记L R O 位于嫦娥四号正上方的时间点，指示剂量率值是此时的测量值Fig. 5 Dose rate measurements by L N D and C R a T E R. Dose rates measured by C R a T E R are corrected for the geometrical shielding provided by the Moon. T h e vertical line marks the time point w h e n L R O was located rightabove C h a n g 5E-4, and the dose rate values indicated in the panels are the values measured at this timeC R a T E R不同.LN D也能够测量更低能试的粒子，这 些低能粒子比能M 更高、穿透力更强的粒子更多，对 剂量率的贡献也更大.L N D与C R a T E R测量能量范围不同对剂量结果的影响可以通过具体实例看到，通过对比同一时间 段、同一位置（2019年2月2日01:30U T) LN D和C R a T E R测量值可以看出1^0和〇^丁瓦11覆 盖不同能量测量范围对剂量的影响（见图5).此时. 两台仪器都处于相同的日球层条件，但在各自测量上 下能量截止阈值上存在差异.图5给出了 LN D和C R a T E R 在2019年初L N D活动时间段的测量，垂直线表示LR O和嫦娥四号在月球经纬度大致相同的时间段.并在图中给 出了测M 剂t t 率值.结果表明，D 1和D2的剂量率为 13.2/i G y .h -1, LN D剂量率为 13.29/i G y .h -1，L N D测量的剂量率与C R a T E R的结果十分类似.需要注意的是，月球的屏蔽效应已经在公布的CR a-T E R剂量率数据中得到修正，但是如果没有详细考虑两种仪器的响应范围及其屏蔽差异.仍然不能比 较C R a T E R和L N D的剂量率.虽然LN D的B探测器由于其位于LN D和嫦娥四号着陆器内受到不同程度的屏蔽，但C R a T E R的D1和D2探测器也表1不同时间段内不同轨道测量到的月球辐射剂量率T a b le 1D o se r a te m e a s u re d in d iffe re n t o rb its o f th e M o o n a t d iffe re n t tim e卫星测量时间段轨道高度/k m辐射剂 f i /k G y.h -1)未被月球遮挡/(%)参考文献Chandrayaan-1 3 to 8 Nov. 200820 000〜30 00012.76100[18]Chandrayaan-120 M a y to 28 Aug. 200920010.772[18]Chandrayaan-120 Nov. 2008 to 18 M a y 20091009.7666[18]L R O 17 Sept. 2009 to 31 M a y 2010509.17 〜11.2562[19]C h a n g ’E-41 M a y 2019 to 19 Jan. 202012.6650一LND-M ^o5/o x.£)c 】ll被来自仪器和LR O 卫星的不同材料厚度屏蔽.CRa-T E R 探测器D1 (148/m i)探测器由0.82 m m 厚的铝入口窗口屏蔽，其1m m 厚的D 2探测器被0.82mmA1和148 y m 的硅屏蔽.LND 的B 探测器在最小屏蔽方向上被25/xm 的A1及50/xm 的kapton 和0.5 mm 的硅屏蔽.本文的测量结果涵盖了 LND 在月表两年的辐射 剂量结果，这些结果与未来人类月球任务的安排和规 划直接相关.参考文献[1] N A S A. 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Educational Practice and Research原始物理问题（Primitive physics problem），又称为现实问题，是物理学习的根基，是自然界及生活生产中客观存在并且没有被加工的物理现象及规律的真实描述，是最真实、最原始、且高度原生态性的物理问题。

物理中的绝大多数问题都是在原始物理问题的基础上通过融入一定的情境然后经过改编、概括、抽象等形成的，是在一定程度上进行抽象化形成的问题。

学生在解答这些原始物理问题时无须复杂的科学思维，如概括、建模、推理、赋值等，只需要根据原始物理问题直接解答即可，所以无法感知原始物理问题背后隐藏的深奥物理知识及演绎出的相关物理问题。

为了既解决原始物理问题，又让学生在解决原始物理问题的过程中学习到物理知识，实现科学思维、物理方法的综合应用，需要教师发展学生的科学思维，提升学生的核心素养。

为了在解决原始物理问题的过程中实现科学思维、物理方法地综合应用，本文以北京师范大学邢红军教授提出自组织表征理论为基础，介绍了自组织表征理论的含义及实践意义，以及以此为基础解决原始物理问题的五条策略和研究方法，即1.结合生活素材，演绎常见问题，以调动学生的学习积极性；2.结合实际情境，建构物理模型，以培养学生的科学建模能力；3.结合感知的现象，实现科学推理，以助推学生科学思维的发展；4.结合认知冲突，关注知识建构，以提升学生科学分析问题的能力；5.结合生活实际，应用物理规律，以培养学生进行综合实践活动的能力。

一、自组织表征理论的含义及实践意义自组织表征理论（Self-Organization Repre-sentative Theory），简称SORT，是解决原始物理问题的一种基本方法。

其认为问题的解决是一个动态的过程，问题表征贯穿从问题呈现到问题解决始终。

这里的问题表征是答题者根据问高柏林，侯中柱（宝应开发区国际学校，江苏扬州225800）摘要：为了深入解决原始物理问题，教师们以北京师范大学邢红军教授提出的自组织表征理论为基础，介绍了自组织表征理论的含义及实践意义，以及以此为基础解决原始物理问题的五条策略和研究方法，即演绎问题、物理建模、科学推理、知识建构、应用规律，以期给广大物理教师以启示。

[日期] 2 005 年全国硕士研究生入学统一考试英语试题Section I Use of EnglishDirections:Read the following text. Choose the best word(s) for each numbered blank and mark [A], [B], [C] or [D] on ANSWER SHEET 1 (10 points)The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, 1 this is largely because, 2animals, we stand upright. This means that our noses are 3 to perceiving those smells which float through the air, 4 the majority of smells which stick to surfaces. In fact, 5 , we are extremely sensitive to smells, 6 we do not generally realize it. Our noses are capable of 7 human smells even when these are 8 to far below one part in one million.Strangely, some people find that they can smell one type of flower but not another, 9 others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate 10 smell receptors in the nose. These receptors are the cells which sense smells and send 11to the brain. However, it has been found that even peopleinsensitive to a certain smell12 can suddenly become sensitive to it when 13to it often enough.The explanation for insensitivity to smell seems to be that brain finds it 14 to keep all smell receptors working all the time but can 15 new receptors if necessary. This may 16 explain why we are not usually sensitive to our own smells —we simply do not need to be. We are not 17 of the usual smell of our own house, but we 18 new smells when we visit someone else’s. The brain finds it best to keep smell receptors 19 for unfamiliar and emergency signals 20 the smell of smoke, which might indicate the danger of fire.1 2 3 4 5 6 7 8 9 1 1 1 1 1 .[A] although .[A] above [B] as [C] but [D] while[B] unlike [B] committed [B] ignoring [B] though [B] if only [C] excluding [C] dedicated [C] missing [C] instead [C] only if [D] besides[D] confined[D] tracking[D] therefore[D] as if.[A] limited .[A] catching .[A] anyway .[A] even if .[A]distinguishing [B] discovering [C] determining [D] detecting.[A] diluted .[A] when [B] dissolved [B] since [C] dispersed [C] for [D] diffused[D] whereas[D] typical0.[A] unusual 1.[A] signs [B] particular [B] stimuli [B] at all [C] unique [C] messages [C] at large [C] drawn [D] impulses[D] at times[D] exposed[D] insufficient2.[A] at first3.[A] subjected [B] left4.[A] ineffective [B] incompetent [C] inefficient1 1 1 27.[A]sure[B]sick[C]aware[C]neglect[D]tired[D]notice8.[A]tolerate9.[A]available0.[A]similar to[B]repel[B]reliable[C]identifiable[D]suitable[B]such as[C]along with[D]aside fromSection II Reading ComprehensionPart ADirections:Read the following four texts.Answer the questions below each text by choosing[A],[B],[C]or[D].Mark your answers on ANSWER SHEET1.(40points)Text1Everybody loves a fat pay rise.Yet pleasure at your own can vanish if you learn that a colleague has been given a bigger one.Indeed,if he has a reputation for slacking,you might even be outraged.Such behaviour is regarded as“all too human”,with the underlying assumption that other animals would not be capable of this finely developed sense of grievance.But a study by Sarah Brosnan and Frans de Waal of Emory University in Atlanta,Georgia,which has just been published in Nature,suggests that it is all too monkey,as well.The researchers studied the behaviour of female brown capuchin monkeys.They look cute.They are good-natured,co-operative creatures,andthey share their food readily.Above all,like their female human counterparts,they tend to pay much closer attention to the value of“goods and services”than males.Such characteristics make them perfect candidates for Dr.Brosnan’s and Dr.de Waal’s study.The researchers spent two years teaching their monkeys to exchange tokens for food.Normally,the monkeys were happy enough to exchange pieces of rock for slices of cucumber.However,when two monkeys were placed in separate but adjoining chambers,so that each could observe what the other was getting in return for its rock,their behaviour became markedly different.In the world of capuchins grapes are luxury goods(and much preferable to cucumbers).So when one monkey was handed a grape in exchange for her token,the second was reluctant to hand hers over for a mere piece of cucumber.And if one received a grape without having to provide her token in exchange at all,the other either tossed her own token at the researcher or out of the chamber,or refused to accept the slice of cucumber.Indeed, the mere presence of a grape in the other chamber(without an actual monkey to eat it)was enough to induce resentment in a female capuchin.The researchers suggest that capuchin monkeys,like humans,are guided by social emotions.In the wild,they are a co-operative,group-living species.Such co-operation is likely to be stable only when each animal feels it is not being cheated.Feelings of righteous indignation,it seems,are not the preserve of people alone.Refusing a lesser reward completely makes these feelings abundantly clear to other members of the group.However, whether such a sense of fairness evolved independently in capuchins and humans,or whether it stems from the common ancestor that the species had35million years ago,is,as yet,an unanswered question.21.In the opening paragraph,the author introduces his topic by________.[ [ [ [A]posing a contrastB]justifying an assumptionC]making a comparisonD]explaining a phenomenon22.The statement“it is all too monkey”(Last line,Paragraph l)implies that________.[ [ [ [A]monkeys are also outraged by slack rivalsB]resenting unfairness is also monkeys’natureC]monkeys,like humans,tend to be jealous of each otherD]no animals other than monkeys can develop such emotions23.Female capuchin monkeys were chosen for the research most probably because they are________.[A]more inclined to weigh what they get[B]attentive to researchers’instructions[C]nice in both appearance and temperament[D]more generous than their male companions24.Dr.Brosnan and Dr.de Waal have eventually found in their study that the monkeys________.[ [ [ [A]prefer grapes to cucumbersB]can be taught to exchange thingsC]will not be co-operative if feeling cheatedD]are unhappy when separated from others25.What can we infer from the last paragraph?[A]Monkeys can be trained to develop social emotions.[B]Human indignation evolved from an uncertain source.[C]Animals usually show their feelings openly as humans do.[D]Cooperation among monkeys remains stable only in the wild.Text2Do you remember all those years when scientists argued that smoking would kill us but the doubters insisted that we didn’t know for sure?That the evidence was inconclusive,the science uncertain?That the antismoking lobby was out to destroy our way of life and the government should stay out of the way?Lots of Americans bought that nonsense,and over three decades,some10million smokers went to early graves.There are upsetting parallels today,as scientists in one wave after another try to awaken us to the growing threat of global warming.The latestwas a panel from the National Academy of Sciences,enlisted by the White House,to tell us that the Earth’s atmosphere is definitely warming and that the problem is largely man-made. The clear message is that we should get moving to protect ourselves.The president of the National Academy, Bruce Alberts,added this key point in the preface to the panel’s report:“Science never has all the answers.But science does provide us with the best available guide to the future,and it is critical that our nation and the worldbase important policies on the best judgments that science can provide concerning the future consequences of present actions.”Just as on smoking,voices now come from many quarters insisting that the science about global warming is incomplete,that it’s OK to keep pouring fumes into the air until we know for sure.This is a dangerous game:by the time100percent of the evidence is in,it may be too late.With the risks obvious and growing,a prudent people would take out an insurance policy now.Fortunately,the White House is starting to pay attention.But it’s obvious that a majority of the president’s advisers still don’t take global warming seriously.Instead of a plan of action,they continue to press for more research—a classic case of“paralysis by analysis”.To serve as responsible stewards of the planet,we must press forward on deeper atmospheric and oceanic research.But research alone is inadequate.If the Administration won’t take the legislative initiative,Congress should help to begin fashioning conservation measures.A bill by Democratic Senator Robert Byrd of West Virginia,which would offer financial incentives for private industry,is a promising start.Many see that the country is getting ready to build lots of new power plants to meet our energy needs.If we are ever going to protect the atmosphere,it is crucial that those new plants be environmentally sound.26.An argument made by supporters of smoking was that________.[ [ [ [A]there was no scientific evidence of the correlation between smoking and deathB]the number of early deaths of smokers in the past decades was insignificantC]people had the freedom to choose their own way of lifeD]antismoking people were usually talking nonsense27.According to Bruce Alberts,science can serve as________.[ [ [ [A]a protectorB]a judgeC]a criticD]a guide28.What does the author mean by“paralysis by analysis”(Last line,Paragraph4)?[ [ [ [A]Endless studies kill action.B]Careful investigation reveals truth.C]Prudent planning hinders progress.D]Extensive research helps decision-making.29.According to the author,what should the Administration do about global warming?[A]Offer aid to build cleaner power plants.[B]Raise public awareness of conservation.[C]Press for further scientific research.[D]Take some legislative measures.30.The author associates the issue of global warming with that of smoking because______.[A]they both suffered from the government’s negligenceB]a lesson from the latter is applicable to the former[[C]the outcome of the latter aggravates the formerD]both of them have turned from bad to worse[Text3Of all the components of a good night’s sleep,dreams seem to be least within our control.In dreams,a window opens into a world where logic is suspended and dead people speak.A century ago,Freud formulated his revolutionary theory that dreams were the disguised shadows of our unconscious desires and fears;by the late 1970s,neurologists had switched to thinking of them as just“mental noise”—the random byproducts of the neural-repair work that goes on during sleep.Now researcherssuspect that dreams are part of the mind’s emotional thermostat,regulating moods while the brain is“off-line.”And one leading authority says that these intensely powerful mental events can be not only harnessed but actually brought under conscious control,to help us sleep and feel better.“It’s your dream,”says Rosalind Cartwright,chair of psychology at Chicago’s Medical Center.“If you don’t like it,change it.”Evidence from brain imaging supports this view.The brain is as active during REM(rapid eye movement) sleep—when most vivid dreams occur—as it is when fully awake,says Dr.Eric Nofzinger at the University of Pittsburgh.But not all parts of the brain are equally involved;the limbic system(the“emotional brain”)is especially active,while the prefrontal cortex(the center of intellect and reasoning)is relatively quiet.“We wake up from dreams happy or depressed,and those feelings can stay with us all day.”says Stanford sleep researcher Dr.William Dement.The link between dreams and emotions shows up among the patients in Cartwright’s clinic.Most people seem to have more bad dreams early in the night,progressing toward happier ones before awakening,suggesting that they are working through negative feelings generated during the day.Because our conscious mind is occupied with daily life we don’t always think about the emotional significance of the day’s events—until,it appears,we begin to dream.And this process need not be left to the unconscious.Cartwright believes one can exercise conscious control over recurring bad dreams.As soon as you awaken,identify what is upsetting about the dream.Visualize how you would like it to end instead;the next time it occurs,try to wake up just enough to control its course.With much practice people can learn to,literally,do it in their sleep.At the end of the day,there’s probably little reason to pay attention to our dreams at all unless they keep us from sleeping or“we wake up in a panic,”Cartwright says.Terrorism,economic uncertainties and general feelings of insecurity have increased people’s anxiety.Those suffering from persistent nightmares should seek help from a therapist.For the rest of us,the brain has its ways of working through bad feelings.Sleep—or rather dream—on it and you’ll feel better in the morning.31.Researchers have come to believe that dreams________.[ [ [A]can be modified in their coursesB]are susceptible to emotional changesC]reflect our innermost desires and fears[D]are a random outcome of neural repairs32.By referring to the limbic system,the author intends to show________.[ [ [ [A]its function in our dreamsB]the mechanism of REM sleepC]the relation of dreams to emotionsD]its difference from the prefrontal cortex33.The negative feelings generated during the day tend to________.[ [ [ [A]aggravate in our unconscious mindB]develop into happy dreamsC]persist till the time we fall asleepD]show up in dreams early at night34.Cartwright seems to suggest that________.[A]waking up in time is essential to the ridding of bad dreams[B]visualizing bad dreams helps bring them under control[C]dreams should be left to their natural progression[D]dreaming may not entirely belong to the unconscious35.What advice might Cartwright give to those who sometimes have bad dreams?[ [ [ [A]Lead your life as usual.B]Seek professional help.C]Exercise conscious control.D]Avoid anxiety in the daytime.Text4Americans no longer expect public figures,whether in speech or in writing,to command the Englishlanguage with skill and gift.Nor do they aspire to such command themselves.In his latest book,Doing Our Own Thing:The Degradation of language and Music and Why We Should Like,Care,John McWhorter,a linguist and controversialist of mixed liberal and conservative views,sees the triumph of1960s counter-culture as responsible for the decline of formal English.Blaming the permissive1960s is nothing new,but this is not yet another criticism against the decline in education.Mr.McWhorter’s academic speciality is language history and change,and he sees the gradual disappearance of“whom”,for example,to be natural and no more regrettable than the loss of the case-endings of Old English.But the cult of the authentic and the personal,“doing our own thing”,has spelt the death of formal speech, writing,poetry and music.While even the modestly educated sought an elevated tone when they put pen to paper before the1960s,even the most well regarded writing since then has sought to capture spoken English on the page.Equally,in poetry,the highly personal,performative genre is the only form that could claim real liveliness. In both oral and written English,talking is triumphing over speaking,spontaneity over craft.Illustrated with an entertaining array of examples from both high and low culture,the trend that Mr. McWhorter documents is unmistakable.But it is less clear,to take the question of his subtitle,why we should, like,care.As a linguist,he acknowledges that all varieties of human language,including non-standard ones like Black English,can be powerfully expressive—there exists no language or dialect in the world that cannot convey complex ideas.He is not arguing,as many do,that we can no longer think straight because we do not talk proper. Russians have a deep love for their own language and carry large chunks of memorized poetry in their heads, while Italian politicians tend to elaborate speech that would seem old-fashioned to most English-speakers.Mr. McWhorter acknowledges that formal language is not strictly necessary,and proposes no radical education reforms—he is really grieving over the loss of something beautiful more than useful.We now take our English “on paper plates instead of china”.A shame,perhaps,but probably an inevitable one.6.According to McWhorter,the decline of formal English________.3[ [ [ [A]is inevitable in radical education reformsB]is but all too natural in language developmentC]has caused the controversy over the counter-cultureD]brought about changes in public attitudes in the1960s37.The word“talking”(Line6,Paragraph3)denotes________.[ [ [ [A]modestyB]personalityC]livelinessD]informality38.To which of the following statements would McWhorter most likely agree?[A]Logical thinking is not necessarily related to the way we talk.[B]Black English can be more expressive than standard English.[C]Non-standard varieties of human language are just as entertaining.[D]Of all the varieties,standard English can best convey complex ideas.39.The description of Russians’love of memorizing poetry shows the author’s________.[ [ [ [A]interest in their languageB]appreciation of their effortsC]admiration for their memoryD]contempt for their old-fashionedness40.According to the last paragraph,“paper plates”is to“china”as________.[A]“temporary”is to“permanent”[B]“radical”is to“conservative”[C]“functional”is to“artistic”[D]“humble”is to“noble”Part BDirections:In the following text,some sentences have been removed.For Questions41-45,choose the most suitable one from the list A-G to fit into each of the numbered blanks.There are two extra choices,which do not fit in any of the gaps.Mark your answers on ANSWER SHEET1.(10points)Canada’s premiers(the leaders of provincial governments),if they have any breath left after complaining about Ottawa at their late July annual meeting,might spare a moment to do something,together,to reduce health-care costs.They’re all groaning about soaring health budgets,the fastest-growing component of which are pharmaceutical costs.(41)____________What to do?Both the Romanow commission and the Kirby committee on health care—to say nothing of reports from other experts—recommended the creation of a national drug agency.Instead of each province having its own list of approved drugs,bureaucracy,procedures and limited bargaining power,all would pool resources, work with Ottawa,and create a national institution.(42)_____________But“national”doesn’t have to mean that.“National”could mean interprovincial—provinces combining effortsto create one body.Either way,one benefit of a“national”organization would be to negotiate better prices,if possible,with drug manufacturers.Instead of having one province—or a series of hospitals within a province—negotiate a price for a given drug on the provincial list,the national agency would negotiate on behalf of all provinces.Rather than,say,Quebec,negotiating on behalf of seven million people,the national agency would negotiate on behalf of31million people.Basic economics suggests the greater the potential consumers,the higher the likelihood of a better price.(43)_____________A small step has been taken in the direction of a national agency with the creation of the Canadian Co-ordinating Office for Health Technology Assessment,funded by Ottawa and the provinces.Under it,a Common Drug Review recommends to provincial lists which new drugs should be included.Predictably,and regrettably, Quebec refused to join.A few premiers are suspicious of any federal-provincial deal-making.They(particularly Quebec and Alberta) just want Ottawa to fork over additional billions with few,if any,strings attached.That’s one reason why the idea of a national list hasn’t gone anywhere,while drug costskeep rising fast.(44)_____________Premiers love to quote Mr.Romanow’s report selectively,especially the parts about more federal money. Perhaps they should read what he had to say about drugs:“A national drug agency would provide governments more influence on pharmaceutical companies in order to constrain the ever-increasing cost of drugs.”(45)_____________So when the premiers gather in Niagara Falls to assemble their usual complaint list,they should also get cracking about something in their jurisdiction that would help their budgets and patients.[A] Quebec’s resistance to a national agency is provincialist ideology. One of the first advocates for a national list was a researcher at Laval University. Quebec’s Drug Insurance Fund has seen its costs skyrocket with annual increases from 14.3 per cent to 26.8 per cent![ B] Or they could read Mr. Kirby’s report: “the substantial buying power of such an agency would strengthen the public prescription-drug insurance plans to negotiate the lowest possible purchase prices from drug companies.”C] What does “national” mean? Roy Romanow and Senator Michael Kirby recommended a federal-provincial body much like the recently created National Health Council.D] The problem is simple and stark: health-care costs have been, are, and will continue to increase faster than government revenues.E] According to the Canadian Institute for Health Information, prescription drug costs have risen since 1997 at [ [ [ twice the rate of overall health-care spending. Part of the increase comes from drugs being used to replace other kinds of treatments. Part of it arises from new drugs costing more than older kinds. Part of it is higher prices.[F] So, if the provinces want to run the health-care show, they should prove they can run it, starting with an interprovincial health list that would end duplication, save administrative costs, prevent one province from being played off against another, and bargain for better drug prices.[G] Of course, the pharmaceutical companies will scream. They like divided buyers; they can lobby better that way. They can use the threat of removing jobs from one province to another. They can hope that, if one provinceincludes a drug on its list, the pressure will cause others toinclude it on theirs. They wouldn’t like a national agency, but self-interest would lead them to deal with it.Part CDirections:Read the following text carefully and then translate the underlined segments into Chinese. Your translation should be written clearly on ANSWER SHEET 2. (10 points)It is not easy to talk about the role of the mass media in this overwhelmingly significant phase in European history. History and news become confused, and one’s impressions tend to be a mixture of skepticism and optimism. (46)Television is one of the means by which these feelings are created and conveyed —and perhaps never before has it served so much to connect different peoples and nations as in the recent events in Europe. The Europe that is now forming cannot be anything other than its peoples, their cultures and national identities. With this in mind we can begin to analyze the European television scene. (47) In Europe, as elsewhere, multi-media groups have been increasingly successful; groups which bring together television, radio, newspapers, magazines and publishing houses that work in relation to one another.One Italian example would be the Berlusconi group, while abroad Maxwell and Murdoch come to mind.Clearly, only the biggest and most flexible television companies are going to be able to compete in such a rich and hotly-contested market. (48) This alone demonstrates that the television business is not an easy world to survive in, a fact underlined by statistics that show that out of eighty European television networks, no less than 5 0% took a loss in 1989.Moreover, the integration of the European community will oblige television companies to cooperate more closely in terms of both production and distribution.(49)Creating a“European identity”that respects the different cultures and traditions which go to make up the connecting fabric of the Old Continent is no easy task and demands a strategic choice—that of producing programs in Europe for Europe.This entails reducing our dependence on the North American market,whose programs relate to experiences and cultural traditions which are different from our own.In order to achieve these objectives,we must concentrate more on co-productions,the exchange of news, documentary services and training.This also involves the agreements between European countries for thecreation of a European bank for Television Production which,on the model of the European Investments Bank,will handle the finances necessary for production costs.(50)In dealing with a challenge on such a scale,it is no exaggeration to say,“United we stand,divided we fall”—and if I had to choose a slogan it would be“Unity in our diversity.”A unity of objectives that nonetheless respect the varied peculiarities of each country.Section III WritingPart A51.Directions:Two months ago you got a job as an editor for the magazine Designs&Fashions.But now you find that the work is not what you expected.You decide to quit.Write a letter to your boss,Mr.Wang,telling him your decision,stating your reason(s),and making an apology.Write your letter with no less than100words.Write it neatly on ANSWER SHEET2.Do not sign your own name at the end of the letter;use“Li Ming”instead.You do not need to write the address.(10points)Part B52.Directions:Write an essay of160-200words based on the following drawing.In your essay,you should first describe the drawing,then interpret its meaning,and give your comment on it.You should write neatly on ANSWER SHEET2.(20points)2005年全国硕士研究生入学统一考试英语试题答案与解析Section I Use of English一、文章题材结构分析这是一篇科普性说明文，文章主要介绍了人类嗅觉的特点及原因。

HOW TO EVALUATE A PAPERA thorough understanding and evaluation of a paper involves answering several questions:a. What questions does the paper address?b. What are the main conclusions of the paper?c. What evidence supports those conclusions?d. Do the data actually support the conclusions?e. What is the quality of the evidence?f. Why are the conclusions important?a. What questions does the paper address?Before addressing this question, we need to be aware that research in biochemistry and molecular biology can be of several different types:Type of research Question asked:Descriptive What is there? What do we see?Comparative How does it compare to other organisms? Areour findings general?Analytical How does it work? What is the mechanism? Descriptive research often takes place in the early stages of our understanding of a system. We can't formulate hypotheses about how a system works, or what its interconnections are, until we know what is there. Typical descriptive approaches in molecular biology are DNA sequencing and DNA microarray approaches. In biochemistry, one could regard x-ray crystallography as a descriptive endeavor.Comparative research often takes place when we are asking how general a finding is. Is it specific to my particular organism, or is it broadly applicable? A typical comparative approach would be comparing the sequence of a gene from one organism with that from the other organisms in which that gene is found. One example of this is the observation that the actin genes from humans and budding yeast are 89% identical and 96% similar. Analytical research generally takes place when we know enough to begin formulating hypotheses about how a system works, about how the parts are interconnected, and what the causal connections are. A typical analytical approach would be to devise two (or more) alternative hypotheses about how a system operates. These hypotheses would all be consistent with current knowledge about the system. Ideally, the approach would devise a set of experiments todistinguish among these hypotheses. A classic example is the Meselson-Stahl experiment.Of course, many papers are a combination of these approaches. For instance, researchers might sequence a gene from their model organism; compare its sequence to homologous genes from other organisms; use this comparison to devise a hypothesis for the function of the gene product; and test this hypothesis by making a site-directed change in the gene and asking how that affects the phenotype of the organism and/or the biochemical function of the gene product.Being aware that not all papers have the same approach can orient you towards recognizing the major questions that a paper addresses.What are these questions? In a well-written paper, as described above, the Introduction generally goes from the general to the specific, eventually framing a question or set of questions. This is a good starting place. In addition, the results of experiments usually raise additional questions, which the authors may attempt to answer. These questions usually become evident only in the Results section.b. What are the main conclusions of the paper?This question can often be answered in a preliminary way by studying the abstract of the paper. Here the authors highlight what they think are the key points. This is not enough, because abstracts often have severe space constraints, but it can serve as a starting point. Still, you need to read the paper with this question in mind.c. What evidence supports those conclusions?Generally, you can get a pretty good idea about this from the Results section. The description of the findings points to the relevant tables and figures. This is easiest when there is one primary experiment to support a point. However, it is often the case that several different experiments or approaches combine to support a particular conclusion. For example, the first experiment might have several possible interpretations, and the later ones are designed to distinguish among these.In the ideal case, the Discussion begins with a section of the form "Three lines of evidence provide support for the conclusion that... First, ...Second,... etc." However, difficulties can arise when the paper is poorly written (see above). The authors often do not present a concise summary of this type, leaving you to make it yourself. A skeptic might argue that in such cases the logical structure of the argument is weak and is omitted on purpose! In any case, you need to be sure that you understand the relationship between the data and the conclusions.d. Do the data actually support the conclusions?One major advantage of doing this is that it helps you to evaluate whether the conclusion is sound. If we assume for the moment that the data are believable (see next section), it still might be the case that the data do not actually support the conclusion the authors wish to reach. There are at least two different ways this can happen:i. The logical connection between the data and the interpretation is not soundii. There might be other interpretations that might be consistent with the data.One important aspect to look for is whether the authors take multiple approaches to answering a question. Do they have multiple lines of evidence, from different directions, supporting their conclusions? If there is only one line of evidence, it is more likely that it could be interpreted in a different way; multiple approaches make the argument more persuasive.Another thing to look for is implicit or hidden assumptions used by the authors in interpreting their data. This can be hard to do, unless you understand the field thoroughly.e. What is the quality of that evidence?This is the hardest question to answer, for novices and experts alike. At the same time, it is one of the most important skills to learn as a young scientist. It involves a major reorientation from being a relatively passive consumer of information and ideas to an active producer and critical evaluator of them. This is not easy and takes years to master. Beginning scientists often wonder, "Who am I to question these authorities? After all the paper was published in a top journal, so the authors must have a high standing, and the work must have received a critical review by experts." Unfortunately, that's not always the case. In any case, developing your ability to evaluate evidence is one of the hardest and most important aspects of learning to be a critical scientist and reader.How can you evaluate the evidence?First, you need to understand thoroughly the methods used in the experiments. Often these are described poorly or not at all. The details are often missing, but more importantly the authors usually assume that the reader has a general knowledge of common methods in the field (such as immunoblotting, cloning, genetic methods, or DNase I footprinting). If you lack this knowledge, as discussed above you have to make the extra effort to inform yourself about the basic methodology before you can evaluate the data.Sometimes you have to go to the library, or to a lab that has a lot of back issues of common journals, to trace back the details of the methods if they are important. One new development that eventually will make this much easier is the increasing availability of journals on the Web. Second, you need to know the limitations of the methodology. Every method has limitations, and if the experiments are not done correctly they can't be interpreted.For instance, an immunoblot is not a very quantitative method.Moreover, in a certain range of protein the signal increases (that is, thesignal is at least roughly "linear"), but above a certain amount ofprotein the signal no longer increases. Therefore, to use this methodcorrectly one needs a standard curve that shows that the experimentallanes are in a linear range. Often, the authors will not show thisstandard curve, but they should state that such curves were done. Ifyou don't see such an assertion, it could of course result from badwriting, but it might also not have been done. If it wasn't done, a darkband might mean "there is this much protein or an indefinite amountmore".Third, you need to distinguish between what the data show and what the authors say they show. The latter is really an interpretation on the authors' part, though it is generally not stated to be an interpretation. Papers usually state something like "the data in Fig. x show that ...". This is the authors' interpretation of the data. Do you interpret it the same way? You need to look carefully at the data to ensure that they really do show what the authors say they do. You can only do this effectively if you understand the methods and their limitations.Fourth, it is often helpful to look at the original journal (or its electronic counterpart) instead of a photocopy. Particularly for half-tone figures such as photos of gels or autoradiograms, the contrast is distorted, usually increased, by photocopying, so that the data are misrepresented.Fifth, you should ask if the proper controls are present. Controls tell us that nature is behaving the way we expect it to under the conditions of the experiment. If the controls are missing, it is harder to be confident that the results really show what is happening in the experiment. You should try to develop the habit of asking "where are the controls?" and looking for them.f. Why are the conclusions important?Do the conclusions make a significant advance in our knowledge? Do they lead to new insights, or even new research directions?Again, answering these questions requires that you understand the field relatively well. (John W. L ittle and Roy Parker--University of Arizona)。

收稿日期：2015－07－25修回日期：2015－11－05网络出版时间：2016－05－05基金项目：国家自然科学基金资助项目（61071167，61373137）；江苏省研究生科研创新计划项目（KYZZ_0233）作者简介：周飞飞（1990－），女，硕士研究生，研究方向为非线性分析及应用；李雷，博士，教授，研究方向为智能信号处理和非线性科学及其在通信中的应用。

网络出版地址：http ：//www．cnki．net /kcms /detail /61．1450．TP．20160505．0817．050．html广义贝叶斯字典学习K －SVD 稀疏表示算法周飞飞，李雷（南京邮电大学理学院，江苏南京210023）摘要：稀疏字典学习是一种功能强大的视频图像稀疏表示方法，在稀疏信号处理领域引起了广泛关注。

K －SVD 算法在稀疏表示技术上取得了巨大成功，但遇到了字典原子未充分利用的问题，而稀疏贝叶斯字典学习（Sparse Bayesian Dictiona-ry Learning ，SBDL ）算法存在稀疏表示后信号原子不稀疏和不收敛的缺点。

广义贝叶斯字典学习（Generalized Bayesian Dic-tionary Learning ，GBDL ）K －SVD 算法提供了一种新型稀疏表示系数更新模式，使得过完备字典稀疏学习算法逐步收敛的同时训练向量足够稀疏。

仿真结果表明，对有损像素和压缩传感这两种视频图像帧进行稀疏化，GBDL K －SVD 算法表示的视频图像帧的重构效果与SBDL K －SVD 算法相比有明显的提高。

关键词：稀疏贝叶斯学习；视频图像稀疏表示；字典学习；K －SVD 算法中图分类号：TP301．6文献标识码：A文章编号：1673－629X （2016）05－0071－05doi ：10．3969/j．issn．1673－629X．2016．05．015K －SVD Sparse Ｒepresentation Algorithm of Generalized Bayesian Dictionary LearningZHOU Fei －fei ，LI Lei（College of Science ，Nanjing University of Posts and Telecommunications ，Nanjing 210023，China ）Abstract ：Sparse dictionary learning is a powerful sparse representation method for video image which has attracted much attention in ex-ploiting sparsity in signal processing．The K －SVD algorithm has achieved success in sparse representation but suffers from the problem of underutilization of dictionary atoms．Sparse Bayesian Dictionary Learning （SBDL ）algorithm exists the drawbacks of non －sparse rep-resentation and convergence of signal atoms．But Generalized Bayesian Dictionary Learning （GBDL ）K －SVD algorithm offers a novel update mode of sparse represent coefficient to make the learning algorithm gradually convergent and give the training vectors a perfect op-portunity to become extremely sparsity over the overcomplete dictionary．The simulation experiment of two cases where image frames with missing pixels and ones based on compressive sensing shows that the efficiency of sparsely represent by GBDL K －SVD algorithm is better than SBDL K －SVD algorithm．Key words ：sparse Bayesian learning ；video image sparse representation ；dictionary learning ；K －SVD algorithm0引言近年来，信号的过完备字典［1］稀疏表示已成为重要的科研议题并引起了广泛的研究和讨论。

2001年Text 1●Specialization can be seen as a response to the problem of an increasing accumulation of scientific knowledge.By splitting up the subject matter into smaller units, one man could continue to handle the information and use it as the basis for further research.But specialization was only one of a series of related developments in science affecting the process of communication. Another was the growing professionalisation of scientific activity.●No clear-cut distinction can be drawn between professionals and amateurs in science: exceptions can be found to any rule.Nevertheless, the word “amateur” does carry a connotation that the person concerned is not fully integrated into the scientific community and, in particular, may not fully share its values.The growth of specialization in the nineteenth century, with its consequent requirement of a longer, morecomplex training, implied greater problems for amateur participation in science.The trend was naturally most obvious in those areas of science based especially on a mathematical or laboratory training, and can be illustrated in terms of the development of geology in the United Kingdom.●A comparison of British geological publications over the last century and a half reveals not simply an increasing emphasis on the primacy of research, but also a changing definition of what constitutes an acceptable research paper.Thus, in the nineteenth century, local geological studies represented worthwhile research in their own right; but, in the twentieth century, local studies have increasingly become acceptable to professionals only if they incorporate, and reflect on, the wider geological picture.Amateurs, on the other hand, have continued to pursue local studies in the old way. The overall result hasbeen to make entrance to professional geological journals harder for amateurs, a result that has been reinforced by the widespread introduction of refereeing, first by national journals in the nineteenth century and then by several local geological journals in the twentieth century.As a logical consequence of this development, separate journals have now appeared aimed mainly towards either professional or amateur readership.A rather similar process of differentiation has led to professional geologists coming together nationally within one or two specific societies, whereas the amateurs have tended either to remain in local societies or to come together nationally in a different way.●Although the process of professionalisation and specialization was already well under way in British geology during the nineteenth century, its full consequences were thus delayed until the twentieth century.In science generally, however, the nineteenth century must be reckoned as the crucial period for this change in the structure of science.51. The growth of specialization in the 19th century might be more clearly seen in sciences such as ________.[A] sociology and chemistry[B] physics and psychology[C] sociology and psychology[D] physics and chemistry52. We can infer from the passage that ________.[A] there is little distinction between specialization and professionalisation[B] amateurs can compete with professionals in some areas of science[C] professionals tend to welcome amateurs into the scientific community[D] amateurs have national academic societies but no local ones53. The author writes of the development of geology to demonstrate ________.[A] the process of specialization and professionalisation[B] the hardship of amateurs in scientific study[C] the change of policies in scientific publications[D] the discrimination of professionals against amateurs54. The direct reason for specialization is ________.[A] the development in communication[B] the growth of professionalisation[C] the expansion of scientific knowledge[D] the splitting up of academic societiesText 2●A great deal of attention is being paid today to the so-called digital divide -- the division of the world into the info (information) rich and the info poor. And that divide does exist today.My wife and I lectured about this looming danger twenty years ago. What was less visible then, however, were the new, positive forces that work against the digital divide. There are reasons to be optimistic.●There are technological reasons to hope the digital divide will narrow. As the Internet becomes more and more commercialized, it is in the interest of business to universalize access -- after all, the more people online, the more potential customers there are.More and more governments, afraid their countries will be left behind, want to spread Internet access. Within the next decade or two, one to two billion people on the planet will be netted together.As a result, I now believe the digital divide will narrow rather than widen in the years ahead. And that is very good news because the Internet may well be the most powerful tool for combating world poverty that we’ve ever had.Of course, the use of the Internet isn’t the only way to defeat poverty. And the Internet is not the only tool we have. But it has enormous potential.●To take advantage of this tool, some impoverished countries will have to get over their outdated anti-colonial prejudices with respect to foreign investment.Countries that still think foreign investment is an invasion of their sovereignty might well study the history of infrastructure (the basic structural foundations of a society) in the United States.When the United States built its industrial infrastructure, it didn’t have the capital to do so. And that is why America’s Second Wave infrastructure -- including roads, harbors, highways, ports and so on -- were built with foreign investment.The English, the Germans, the Dutch and the French were investing in Britain’s former colony. They financed them. Immigrant Americans built them. Guess who owns them now?The Americans. I believe the same thing would be true in places like Brazil or anywhere else for that matter.The more foreign capital you have helping you build your Third Wave infrastructure, which today is an electronic infrastructure, the better off you’re going to be.That doesn’t mean lying down and becoming fooled, or letting foreign corporations run uncontrolled. But it does mean recognizing how important they can be in building the energy and telecom infrastructures needed to take full advantage of the Internet.55. Digital divide is something ________.[A] getting worse because of the Internet[B] the rich countries are responsible for[C] the world must guard against[D] considered positive today56. Governments attach importance to the Internet because it ________.[A] offers economic potentials[B] can bring foreign funds[C] can soon wipe out world poverty[D] connects people all over the world57. The writer mentioned the case of the United States to justify the policy of ________.[A] providing financial support overseas[B] preventing foreign capital’s control[C] building industrial infrastructure[D] accepting foreign investment58. It seems that now a country’s economy depends much on ________.[A] how well developed it is electronically[B] whether it is prejudiced against immigrants[C] whether it adopts America’s industrial pattern[D] how much control it has over foreign corporationsText 3●Why do so many Americans distrust what they read in their newspapers? The American Society of Newspaper Editors is trying to answer this painful question. The organization is deep into a long self-analysis known as the journalism credibility project.●Sad to say, this project has turned out to be mostly low-level findings about factual errors and spelling and grammar mistakes, combined with lots of head-scratching puzzlement about what in the world those readers really want.●But the sources of distrust go way deeper. Most journalists learn to see the world through a set of standard templ ates (patterns) into which they plug each day’s events.In other words, there is a conventional story line in the newsroom culture that provides a backbone and a ready-made narrative structure for otherwise confusing news.●There exists a social and cultural disconnect between journalists and their readers, which helps explain why the “standard templates” of the newsroom seem alien to many readers.In a recent survey, questionnaires were sent to reporters in five middle-size cities around the country, plus one large metropolitan area. Then residents in these communities were phoned at random and asked the same questions.●Replies show that compared with other Americans, journalists are more likely to live in upscale neighborhoods, have maids, own Mercedeses, and trade stocks, and they’re less likely to go to church, do volunteer work, or put down roots in a community.●Reporters tend to be part of a broadly defined social and cultural elite, so their work tends to reflect the conventional values of this elite.The astonishing distrust of the news media isn’t rooted in inaccuracy or poor reportorial skills but in the daily clash of world views between reporters and their readers.●This is an explosive situation for any industry, particularly a declining one. Here is a troubled business that keeps hiring employees whose attitudes vastly annoy the customers.Then it sponsors lots of symposiums and a credibility project dedicated to wondering why customers are annoyed and fleeing in large numbers.But it never seems to get around to noticing the cultural and class biases that so many former buyers are complaining about. If it did, it would open up its diversity program, now focused narrowly on race and gender, and look for reporters who differ broadly by outlook, values, education, and class.59. What is the passage mainly about?[A] needs of the readers all over the world[B] causes of the public disappointment about newspapers[C] origins of the declining newspaper industry[D] aims of a journalism credibility project60. The results of the journalism credibility project turned out to be ________.[A] quite trustworthy[B] somewhat contradictory[C] very illuminating[D] rather superficial61. The basic problem of journalists as pointed out by the writer lies in their ________.[A] working attitude[B] conventional lifestyle[C] world outlook[D] educational background62. Despite its efforts, the newspaper industry still cannot satisfy the readers owing to its ________.[A] failure to realize its real problem[B] tendency to hire annoying reporters[C] likeliness to do inaccurate reporting[D] prejudice in matters of race and genderText 4●The world is going through the biggest wave of mergers and acquisitions ever witnessed. The process sweeps from hyperactive America to Europe and reaches the emerging countries with unsurpassed might.Many in these countries are looking at this process and worrying: “Won’t the wave o f business concentration turn into an uncontrollable anti-competitive force?”●There’s no question that the big are getting bigger and more powerful. Multinational corporations accounted for less than 20% of international trade in 1982.Today the figure is more than 25% and growing rapidly. International affiliates account for a fast-growing segment of production in economies that open up and welcome foreign investment.In Argentina, for instance, after the reforms of the early 1990s, multinationals went from 43% to almost 70% of the industrial production of the 200 largest firms.This phenomenon has created serious concerns over the role of smaller economic firms, of national businessmen and over the ultimate stability of the world economy.●I believe that the most important forces behind the massive M&A wave are the same that underlie theglobalization process: falling transportation and communication costs, lower trade and investment barriers and enlarged markets that require enlarged opera tions capable of meeting customer’s demands.All these are beneficial, not detrimental, to consumers. As productivity grows, the world’s wealth increases.●Examples of benefits or costs of the current concentration wave are scanty. Y et it is hard to imagine that the merger of a few oil firms today could recreate the same threats to competition that were feared nearly a century ago in the U.S., when the Standard Oil trust was broken up.The mergers of telecom companies, such as WorldCom, hardly seem to bring higher prices for consumers or a reduction in the pace of technical progress.On the contrary, the price of communications is coming down fast. In cars, too, concentration is increasing-- witness Daimler and Chrysler, Renault and Nissan -- but it does not appear that consumers are being hurt.●Y et the fact remains that the merger movement must be watched. A few weeks ago, Alan Greenspan warned against the megamergers in the banking industry.Who is going to supervise, regulate and operate as lender of last resort with the gigantic banks that are being created?Won’t multinationals shift production from one place to another when a nation gets too strict about infringements to fair competition?And should one country take upon its elf the role of “defending competition” on issues that affect many other nations, as in the U.S. vs. Microsoft case?63. What is the typical trend of businesses today?[A] to take in more foreign funds[B] to invest more abroad[C] to combine and become bigger[D] to trade with more countries64. According to the author, one of the driving forces behind M&A wave is ________.[A] the greater customer demands[B] a surplus supply for the market[C] a growing productivity[D] the increase of the world’s weal th65. From Paragraph 4 we can infer that ________.[A] the increasing concentration is certain to hurt consumers[B] WorldCom serves as a good example of both benefits and costs[C] the costs of the globalization process are enormous[D] the Standard Oil trust might have threatened competition66. Toward the new business wave, the writer’s attitude can be said to be ________.[A] optimistic[B] objective[C] pessimistic[D] biasedText 5●When I decided to quit my full time employment it never occurred to me that I might become a part of a new international trend.A lateral move that hurt my pride and blocked my professional progress prompted me to abandon my relatively high profile career although, in the manner of a disgraced government minister, I covered my exit by claiming “I wanted to spend more time with my family”.●Curiously, some two-and-a-half years and two novels later, my experiment in what the Americans term “downshifting” has turned my tired excuse into an absolute reality.I have been transformed from a passionate advocate of the philosophy of “having it all,” preached by Linda Kelsey for the past seven years in the page of She magazine, into a woman who is happy to settle for a bit of everything.●I have discovered, as perhaps Kelsey will after her much-publicized resignation from the editorship ofShe after a build-up of stress, that abandoning the doctrine of “juggling your life,” and making the alternative move into “downshifting” brings with it far greater rewards than financial success and social status.Nothing could persuade me to return to the kind of life Kelsey used to advocate and I once enjoyed: 12-hour working days, pressured deadlines, the fearful strain of office politics and the limitations of being a parent on “quality time”.●In America, the move away from juggling to a simpler, less materialistic lifestyle is a well-established trend. Downshifting -- also known in America as “voluntary simplicity” -- has, ironically, even bred a new area of what might be termed anti-consumerism.There are a number of best-selling downshifting self-help books for people who want to simplify their lives; there are newsletters, such as The Tightwad Gazette, that give hundreds of thousands of Americans useful tips on anything from recycling their cling-film to making their own soap; there are even support groups for those who want to achieve the mid-’90s equivalent of dropping out.●While in America the trend started as a reaction to the economic decline -- after the mass redundancies caused by downsizing in the late ’80s -- and is still linked to the politics of thrift, in Britain, at least among the middle-class downshifters of my acquaintance, we have different reasons for seeking to simplify our lives.●For the women of my generation who were urged to keep juggling through the ’80s, downshifting in the mid-’90s is not so much a search for the mythical good life -- growing your own organic vegetables, and risking turning into one -- as a personal recognition of your limitations.67. Which of the following is true according to Paragraph 1?[A] Full-time employment is a new international trend.[B] The writer was compelled by circumstances to leave her job.[C] “A lateral move” means stepping out of full-time employment.[D] The writer was only too eager to spend more time with her family.68. The writer’s experiment shows that downshifting ________.[A] enables her to realize her dream[B] helps her mold a new philosophy of life[C] prompts her to abandon her high social status[D] leads her to accept the doctrine of She magazine69. “Juggling one’s life” probably means living a life characterized by ________.[A] non-materialistic lifestyle[B] a bit of everything[C] extreme stress[D] anti-consumerism70. According to the passage, downshifting emerged in the U.S. as a result of ________.[A] the quick pace of modern life[B] man’s adventurous spirit[C] man’s search for mythical experiences[D] the economic situation。

·论著·老年人跌倒风险感知研究现状及其对老年人主动跌倒预防的启示聂作婷1，陈龙1，曾凯2，陶璐1，杨如美1*1.211166江苏省南京市，南京医科大学护理学院2.510515广东省广州市，南方医科大学护理学院*通信作者：杨如美，副教授；E-mail ：******************.cn【摘要】　跌倒是老年人致病致死的重要原因。

临床医护人员虽已重视对跌倒的管理，但跌倒干预依从性尚不理想，跌倒发生率仍然维持在较高水平，从老年人角度探讨其对跌倒风险的理解可能是跌倒干预，尤其是主动跌倒预防的关键。

本文从“健康第一责任人”的角度，对老年人跌倒风险感知的概念、行为后果及影响因素进行总结，发现目前国内外跌倒风险感知研究较少，概念内涵仍需进一步挖掘。

老年人对跌倒风险的主观认知能够导致不同的跌倒风险应对行为模式，从而影响跌倒风险。

跌倒风险感知影响因素主要聚焦于情绪心理、生理状况、社会文化和物理环境方面，影响过程均通过主观认知发挥作用。

未来可结合风险感知形成过程，使用实证研究进一步验证跌倒风险感知的心理认知机制，为主动跌倒预防提供实证依据。

【关键词】　跌倒；风险感知；老年人；老年人保健服务；综述【中图分类号】　R 12　R 161.7　【文献标识码】　A　DOI：10.12114/j.issn.1007-9572.2022.0890Current Status of Research on Fall Risk Perception and Its Implications for Active Fall Prevention in Older AdultsNIE Zuoting 1，CHEN Long 1，ZENG Kai 2，TAO Lu 1，YANG Rumei 1*1.School of Nursing ，Nanjing Medical University ，Nanjing 211166，China2.School of Nursing ，Southern Medical University ，Guangzhou 510515，China*Corresponding author ：YANG Rumei ，Associate professor ；E-mail ：******************.cn【Abstract 】　Falls are the important causes of morbidity and mortality in older adults. Although clinical staff have paidattention to the management of falls，adherence to fall interventions is not satisfactory，resulting in the high incidence of fall. Understanding the older adults ' own perception of fall risk from their perspective may be the key to fall prevention，especially active fall prevention. In this paper，we reviewed the concept of fall risk perception，behavioral consequences and influencing factors of fall risk perception in older adults from the perspective of "the first person responsible for health"，and found that there are fewer studies on fall risk perception in older adults at home and abroad，the conceptual connotation still needs to be further explored. Subjective perceptions of fall risk in older adults can lead to different patterns of fall risk coping behaviors that influence fall risk. The influencing factors of fall risk perception mainly focus on the emotional psychology，physiological conditions，social culture，and physical environment，with the influencing process through subjective cognition. Empirical studies can be used to further validate the psychological cognitive mechanisms of fall risk perception in conjunction with the risk perception formation process in the future，in order to provide empirical evidence for proactive fall prevention.【Key words 】　Falls；Risk perception；Aged；Health services for the aged；Review基金项目：国家自然科学基金资助项目（72004098）；江苏高校哲学社会科学研究一般项目（2020SJA0302）；南京医科大学高层次引进人才项目（NMUR2020006）；南京医科大学研究生优质教育资源建设项目（2021F005）；江苏高校优势学科建设工程项目“护理学”（苏政办发〔2018〕87号）；“十四五”高等教育科学研究规划课题（苏高教会〔2021〕16号YB009）；南京医科大学内涵建设专项护理学优势学科资助项目引用本文：聂作婷，陈龙，曾凯，等. 老年人跌倒风险感知研究现状及其对老年人主动跌倒预防的启示［J］. 中国全科医学，2024，27（19）：2395-2400. DOI：10.12114/j.issn.1007-9572.2022.0890.［］NIE Z T，CHEN L，ZENG K，et al. Current status of research on fall risk perception and its implications for active fall prevention in older adults ［J］. Chinese General Practice，2024，27（19）：2395-2400.© Editorial Office of Chinese General Practice. This is an open access article under the CC BY-NC-ND 4.0 license.扫描二维码查看原文跌倒是老年人致病致死的重要原因，因其结局的致命性和严重性，各种跌倒干预措施与指南应运而生。