简介：事物都有两面性，优点和缺点共存。在动物园的问题上，人们一直以来都存在争论。动物园是扼杀了动物的天性，还是保护了动物？请阅读下面的文章，了解一下作者的观点。关于动物园的问题，你又有什么想法呢？

简介：人生是短暂的，青春是美好的。年轻的我们常会想方设珐地让自己的人生与众不同．然而，思想叛逆和个性张扬都不是我们用来挥霍青春的资本。拿出你的热情和真诚，去帮助那些需要帮助的人们，这才是对青春无悔最好的诠释。

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简介：Thenaturalworldspentbillionsofyearsinsolution-findingduringevolution,whichcouldbenefitTechnology.Howdoweputthatinanutshell?Biologicalsystemsaremorecomplexthanthemostcomplexcurrenttechnology.Anygivenfunctionandeffectaresimultaneouslycoordinatedandlinkedwithothersatmanylevelsofbiologicalorganisation-fromcellorganelletoorganism,topopulationandecosystem.Technologydoesnothavetoolstodealwiththecomplexityand"goalintendedness"oflivingsystems.Butlimitsforinteractionexistonbothsides-Biologicalscienceitselfisalsotooempiricalandnotmatureenoughtoprovideasolidbaseforcorrelatinglivingwithtechnicalsystems.Movingtowardsasynthesis,whereengineerscanutilizethevastamountofavailablebiologicaldata,wesuggestusingatoolcalled"TheoryofInventiveProblemSolving"(TRIZ)andclarifyingsomeimportantmethodologicalissues,whichhavenotpreviouslybeenrecognisedinbionicengineering:1)Requirenentformoreappropriatedefinitionsof"system","effect","function","law"and"rule".2)Requirementforunderstandingorevenmeasuringthedegreeofcontradictionoranalogybetweenfunctionsinbiologicalandartificialand/ornon-livingengineeringsystem-thereisnosimpledirectcorrelationbetweenwhatengineersfindusefulandwhatbiologydoes.

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简介：长江三角洲(UA-YRD)上的城市的凝块在水，土地，生态的环境，地点和交通的方面有一些优点。依靠资源环境库和另外的优点，UA-YRD完成了大开发。基于索引系统和全面评估的模型，自从1978，纸计算UA-YRD的发展水平。从1978～2007，开发水平以0.0333的年度率逐年增加了的结果表演，和开发的进程能被划分成三个阶段，即低速度的开发舞台(19781991)，快速的开发舞台(19912000)，并且高速度的开发舞台(20002007)。速度分别地是0.0083，0.0356和0.0766。在30年的发展期间，外国经济活动在开发有最大的效果，由交通，工业经济活动和电信列在后面(有序)。另外，不同驱动力在不同阶段有不同效果。纸建议更多的注意应该对高速度的发展阶段和重要驱动力被给予驾驶它的发展。同时，资源和环境的限制不应该被忽视，长有效的机制需要被证实在UA发展，资源利用和环境保护之中支撑和谐开发。一些比较研究应该着急地被执行有效地支持并且支持UA的持续开发，特别向进化，驱动力和braking力量。

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简介：Theuseofoscillatingflexiblefinsinpropulsionhasbeenthesubjectofseveralstudiesinrecentyears,butattentionisrarelypaidtothespecificroleofstiffnessprofileinthrustproduction.Stiffnessprofileisdefinedasthevariationinlocalchordwisebendingstiffness(EI)ofafin,fromleadingtotrailingedge.Inthisstudy,flexiblefinswithastandardNACA0012shapeweretestedalongsidefinswithastiffnessprofilemimickingthatofaPumpkinseedSunfish(Lepomisgibbosus).Thefinswereoscillatedwithapitchingsinusoidalmotionoverarangeoffrequenciesandamplitudes,whiletorque,lateralforceandstaticthrustweremeasured.Overtherangeofoscillationparameterstested,itwasshownthatthefinwithabiomimeticstiffnessprofileofferedasignificantimprovementinstaticthrust,comparedtoafinofsimilardimensionswithastandardNACA0012aerofoilprofile.Thebiomimeticfinalsoproducedthrustmoreconsistentlyovereachoscillationcycle.Acomparisonoffinmaterialsofdifferentstiffnessshowedthattheimprovementwasduetothestiffnessprofileitself,andwasnotsimplyaneffectofalteringtheoverallstiffnessofthefin.Finsofthesamestiffnessprofilewereobservedtofollowthesamethrust-powercurve,independentofthestiffnessofthemouldingmaterial.Biomimeticfinswereshowntoproduceupto26%greaterthrustperwattofinputpower,withintheexperimentalrange.

简介：Inmedicallaboratoryanimals,thepigistheclosestspeciestohumaninevolution,exceptforprimates.Asananimalmodel,thepigishighlyconcernedbymanyscientists,includingcomparativebiology,developmentalbiology,medicalgenetics.Rodentsasanimalmodelforhumanhearingdefectshasarepoorproducibilityandreliability,duetodifferencesinanatomicalstructure,evolutionaryrateandmetabolicrate,butthesehappenstobetheadvantagesofthepigmodel.Inthispaper,wewillsummarizetheapplicationofminiaturepiginthestudyofhumanhereditarydeafness.

简介：ForChinaandLatinAmerica,the21thcenturyisacenturyinwhichgreatprogresscouldbeachieved.Astheeconomicglobalizationsweepsitswayacrosstheworld,interdependencybetweencountrieswillbeenhanced,andrelationsbetweenChinaandLatinAmericatendtobeevencloser.

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简介：正AsanimportantparticipantinChina'speople-to-peoplediplomacy,theChineseAssociationforInternationalUnderstanding(CAFIU)hasbeenplayingapositiveroleinpromotingdialogueandexchangesbetweenChinaandtherestoftheworld,particularlyinlettingtheworldunderstand

简介：Weproposetheuseofapowerpulseshapeofthewidelyknownopticalsoliton,correspondingtothehyperbolicsecantsquarefunction,forbothconventionalatmosphericopticalcommunicationsystemsand,especially,fornewfull-opticalwirelesscommunications.Weanalyzetheperformanceoftheproposedpulseintermsofpeak-to-averageopticalpowerratio(PAOPR)andbiterrorrate(BER).Duringtheanalysis,wecomparetheproposedpulseshapeagainstconventionalrectangularandGaussianpulseshapeswithreduceddutycycle.Resultsshowthenoticeablesuperiorityoftheproposedpulseforatmosphericopticallinks.

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简介：Existinglarge-scalepublicbuildingenergysavingrenovationistheinherentrequirementofsustainabledevelopment,ithasbeenprovedthatimplementingtheenergyperformancecontractingmodeintheExistinglargepublicbuildingsenergy-savingisaneffectivewaybothathomeandabroad.EPCmodehasobviouscharacteristicsfortheESCOandthecustomers,itcanmeetthebasicrequirementsoflargepublicbuildingsenergy-saving,suchasthewidthoffundingsources,programspecification,advancedtechnology,informationflowandmanagementlevelhigher,etc.Undertheconditionofmarketeconomy,italsoprovidesabroadplatformfortheESCOimplementsbuildingenergysavingtransformation,whichisconducivetotherealizationofthewin-wincooperationbetweentheparties,andtopromotethehealthydevelopmentoftheexistinglargepublicbuildingenergysavingreconstruction.

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