学科分类
/ 25
500 个结果
  • 简介:Hydrogelcanswelltomanytimesofitsdryvolume,resultinginlargedeformationwhichisvitalforitsfunction.Theswellingprocessisregulatedbymanyphysicalandchemicalmechanisms,andcan,tosomeextent,befairlydescribedbytheporoelasticitytheory.Implementationoftheporoelasticitytheoryintheframeworkoffniteelementmethodwouldaidthedesignandoptimizationofhydrogel-basedsoftdevices.Choosingchemicalpotentialanddisplacementastwofeldvariables,wepresenttheimplementationofporoelasticitytailoredforhydrogelswellingdynamics,detailthenormalizationofphysicalparametersandthetreatmentofboundaryconditions.Severalexamplesarepresentedtodemonstratethefeasibilityandcorrectnessoftheproposedstrategy.

  • 标签: 孔隙弹性理论 有限元方法 水凝胶 溶胀动力学 物理参数 化学机制
  • 简介:Thegradingcriterionofblastingclassification,evaluatingindexandthecharacteristicvaluearetakenasmatterelements.First,therelationalfunctionisconstructedaccordingtothegradingcriterion,andthen,thegradeofrockblastingisevaluatedbythecomprehensiverelationaldegree.Theauthorhaspresentedasystemmethodofblastingclassificationofrock.Thepracticalexampleprovesthatitissimpleincalculationandreasonableinevaluation.

  • 标签: BLASTING CLASSIFICATION of ROCK MATTER element
  • 简介:Amajorroleofecologicalriskassessment(ERA)hasbeentoprovidescientificguidanceonwhetherafuturehumanactivitywillcauseecologicalharm,includingsuchactivitiesasreleaseofageneticallymodifiedorganism(GMO),exoticspecies,orchemicalpollutantintotheenvironment.Thisrequiresthedeterminationofthelikelihoodsthattheactivity:wouldcauseaharm,andwouldnotcauseaharm.Inthefirstcase,thefocusisondemonstratingthepresenceofaharmanddevelopingappropriatemanagementtomitigatesuchharm.Thisisusuallyevaluatedusingstandardhypothesisanalysis.Inthesecondcase,thefocusisondemonstratingtheabsenceofaharmandsupportingadecisionofbiosafety.WhilemostERAresearchershavefocusedonfindingpresenceofharm,andsomehavewronglyassociatedthelackofdetectionofharmwithbiosafety,anovelapproachinERAwouldbetofocusondemonstratingdirectlythesafetyoftheactivity.Although,someresearchershavesuggestedthatretrospectivepoweranalysiscanbeusedtoinferabsenceofharm,itactuallyprovidesinaccurateinformationaboutbiosafety.Adecisionofbiosafetycanonlybesupportedinastatisticallysoundmannerbyequivalencetests,describedhere.Usinga20%ecologicalequivalencestandardinGMOexamples,weillustratedtheuseofequivalencetestsfortwo-sampleswithnormalorbinomialdataandmulti-samplenormaldata,andprovidedaspreadsheetcalculatorforeach.Insixoftheeightexamples,theeffectsofCrytoxinsonanon-targetorganismwereequivalenttoacontrol,supportingadecisionofbiosafety.Theseexamplesalsoshowedthatdemonstrationofequivalencedoesnotrequirelargesamplesizes.Althoughmorerelevantecologicalequivalencestandardsshouldbedevelopedtoenableequivalenceteststobecomethemainmethodtosupportbiosafetydecisionmaking,weadvocatetheiruseforevaluatingbiosafetyfornon-targetorganismsbecauseoftheirdirectandaccurateinferenceregardingsafety.

  • 标签: 安全决策 环境生物 等价 测试 生态危害 转基因生物
  • 简介:Accordingtothebasicideaofdual-complementarity,inasimpleandunifiedwayproposedbytheauthor,somebasicprinciplesindynamictheoryofelasticmaterialswithvoidscanbeestablishedsys-tematically.Inthispaper,animportantintegralrelationintermsofconvolutionsisgiven,whichcanbecon-sideredasthegeneralizedprincipleofvirtualworkinmechanics.Basedonthisrelation,itispossiblenoton-lytoobtaintheprincipleofvirtualworkandthereciprocaltheoremindynamictheoryofelasticmaterialswithvoids,butalsotoderivesystematicallythecomplementaryfunctionalsfortheeight-field,six-field,four-fieldandtwo-fieldsimplifiedGurtin-typevariationalprinciples.Furthermore,withthisapproach,thein-trinsicrelationshipamongvariousprinciplescanbeexplainedclearly.

  • 标签: dynamic theory of ELASTIC materials with
  • 简介:ThispaperisabriefintroductiontoYang-Mills-Higgsmodel,Maxwell-Higgsmodel,Einstein'svacuummodel,Yang-Baxtermodel,Chern-Simons-Higgsmodelandadiscussionoftheassociatedpartialdifferentialequationproblems.

  • 标签: field theory nonlinear analysis PARTIAL DIFFERENTIAL
  • 简介:Basedonthefundamentalideasconcerningmicrowaveattenuationinplasma,weobtainanewexpressionoftransmissionattenuationofmicrowavesasafunctionoftheincidentwavefrequency.Andwithreasonablehypothesis,analyticalformsoftheelectrondensityandtheelectron-neutralcollisionfrequencyarederivedfromtheequationsofthetransmissionattenuationofmicrowavesattwonearfrequencies.Thismethodgivesaneffectiveandeasyapproachtodiagnosetheunmagnetizedplasma.

  • 标签: 非磁化等离子体 诊断理论 解析表达式 双频 碰撞频率 微波衰减
  • 简介:Computervisionhascomeintousedinthefieldsofweldingprocesscontrolandautomation.Inordertoimproveprecisionandrapidityofweldingimageprocessing,anovelmethodbasedonfractaltheoryhasbeenputforwardinthispaper.Comparedwithtraditionalmethods,theimageispreliminarilyprocessedinthemacroscopicregionsthenthoroughlyanalyzedinthemicroscopicregionsinthenewmethod.Withwhich,animageisdivideduptosomeregionsaccordingtothedifferentfractalcharactersofimageedge,andthefuzzyregionsincludingimageedgesaredetectedout,thenimageedgesareidentifiedwithSobeloperatorandcurvedbyLSM(LeaseSquareMethod).Sincethedatatobeprocessedhavebeendecreasedandthenoiseofimagehasbeenreduced,ithasbeentestifiedthroughexperimentsthatedgesofweldseamorweldpoolcouldberecognizedcorrectlyandquickly.

  • 标签: 不规则碎片理论 焊接 图象处理 边缘探测
  • 简介:碳nanocones有相当迷人的电子、结构的性质,其轴的颤动很少在以前的研究被调查。在这份报纸,基于一个非局部的弹性理论,一个不一致的杆模型被使用在nanocones的轴的颤动上调查小规模的效果和不一致的效果。用修改Wentzel-Brillouin-Kramers(WBK)方法,一个asymptotic答案为一般不一致的nanorods的轴的颤动被获得。用类似的过程,然后,nanocones的轴的颤动为不一致的参数,模式数字和非局部的参数被分析。明确的表情为夹钳夹钳和夹钳免费的边界条件的模式频率被导出。因为对小长度规模的效果的无知,轴的颤动频率被古典杆模型高度过高估计,这被发现。

  • 标签: 非局部弹性理论 轴向振动 振动分析 纳米棒 自由边界条件 振动频率
  • 简介:Inmanydomainsofphysics,methodsfordealingwithnon-perturbativeaspectsarerequired.Here,IwanttoarguethatagoodapproachforthisistoworkontheBoreltransformsofthequantitiesofinterest,thesingularitiesofwhichgivenon-perturbativecontributions.ThesesingularitiesinmanycasescanbelargelydeterminedbyusingthealiencalculusdevelopedbyJeanEcalle.Mymainexamplewillbethetwopointfunctionofamasslesstheorygivenasasolutionofarenormalizationgroupequation.

  • 标签: Schwinger-Dyson equations SERIES resommation ALIEN CALCULUS
  • 简介:AmajorissueinChina'spresentecologicaleconomicconstructionistobuildtheecologicalprovince.InMarchof1999,HainanProvinceofChinaproposedsettingupthefirstecologicalprovinceandwasaccreditedbytheBureauofStateEnvironmentProtectionasthepilotproject.Uptonowforonlyfouryears,Hainan,Jilin,Heilongjiang,Fujian,Zhejiang,Shandong,Anhui,Jiangsu,eightprovincesinthewholecountry,havinglaunchedtheestablishmentoftheecologicalprovince.Meanwhile,theprovincessuchasShaanxi,Hebei,

  • 标签: 中国 生态经济学 可持续发展 产业结构 投资环境 经济增长率
  • 简介:在最后对年,分子的成像很快被开发了在细胞、分子的层次在vivo学习生理、病理学的过程。在分子的成像形式之中,光成像为它的唯一的优点,特别表演和划算站出来。Biolummescence断层摄影术(BLT)是有有希望的生物医学的优点的一个新兴的光成像模式。在这份调查报纸,我们解释BLT的生物医学的意义,在分析和散开的数字答案上总结理论结果基于的BLT模型,和对为BLT的学习的一些扩展的评价。

  • 标签: X线断层摄影术 数学理论 计算方法 逼近值
  • 简介:

  • 标签:
  • 简介:TheTwin-LoopAntenna(TLA)hasbeenwidelyusedbecauseofitsbroadbandpropertyandsimplyfeeding,andsomemodifiedstructureshavebeendevel-opedfromitsprototypebyChineseengineers.ButtheexactdesigntheoryforTLAaccord-ingtotheimpedancecalculationhasnotyetbeenpublished.Inthispaper,theimpedanceofloopinaTLAisanalysedandcomputedbyusingthemethodofmoments,andthede-signformulaeandatwo-stepoptimizationprogramforextendingthebandwidthofinputimpedanceofTLAaredetailed.Anexampleofoptimizeddesignshowsthatthebandwidthcanbeincreasedupto36.4%forVSWR≤1.10,whichiswiderthanthebandwidthofra-diationpattern.

  • 标签: ANTENNA BROADBAND MOMENTS method optimization/twin-loop TV
  • 简介:ThispaperextendstheTOPSIStofuzzyMCDMbasedonvaguesettheory,wherethecharacteristicsofthealternativesarerepresentedbyvaguesets.Anovelscorefunctionisproposedinordertodeterminethevaguepositive-idealsolution(VPIS)andvaguenegative-idealsolution(VNIS).Wepresentaweighteddifferenceindextocalculatethedistancebetweenvaguevalues,bymeansofwhichthedistanceofalternativestoVPISandVNIScanbecalculated.Finally,therelativeclosenessvaluesofvariousalternativestothepositive-idealsolutionarerankedtodeterminethebestalternative.Anexampleisshowntoillustratetheprocedureoftheproposedmethodattheendofthispaper.

  • 标签: 模糊理论 多标准决策系统 MCDM问题 矩阵 TOPSIS
  • 简介:OnSeptember11,2017,theSeminaronChina’sTheoryandPracticeoftheRighttoPeacewasheldatNanjingUniversity.ItwasjointlyorganizedbytheChinaSocietyforHumanRightsStudies(CSHRS)andthePublicityDepartmentoftheCommunistPartyofChinaJiangsuProvincialCommittee,andco-hostedbytheInstituteforInternationalStrategicStudiesattheCentralPartySchoolandtheSchoolofHistoryatNanjingUniversity.Morethan70expertsandscholarsfromuniversitiesandhumanrightsinstitutesinChina,andrepresentativesofrelevantgovernmentalagenciesandsocialorganizationsdiscussedindepthtopicsincluding'ResearchontheBasicTheoryoftheRighttoPeace,''PracticeoftheRighttoPeaceandPeaceinChina,''TraditionalChineseHistoryandcultureandtheRighttoPeace,''PeacefulConstructionofaCommunitywithasharedfutureforMankind,''RighttoPeaceandIrenology,'and'PromotionandDisciplineConstructionofIrenology.'ThisseminarhasnotonlyexpoundedChina’speacefuldevelopmentconceptanditsoutstandingcontributionstoworldpeacefromtheperspectiveofhumanrights,butalsofacilitatedtheconstructionofatheoreticalsystemofhumanrightswithChinesecharacteristics.

  • 标签: