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126 个结果
  • 简介:Basedontheassumptionofglobalsealevelrisingbetween30and100cminthefuture100yearsbyIPCC(1990)inadditiontotheeffectoflocalgroundsubsidence,thecoastlinewillretrogradefor50-70kmwhosealtitudeswillbe2.6-3.3maboveMSLofHuanghaiSeainthewesterncoastalareaoftheBohaibayin2100.Thetransgrassiveareaisabout10,000-11,500km.Iftheeffectofset-upofstormsurgeisconsidered,thetransgressiveareawillreach16,000km.Sealevelrisewhichisaseriouscoastaldisasternotonlyinundatesalotofcoastallowland,butalsoincreasesthefrequencyandintensityofstormtides,andresultsinthesalinizationofsoils.Inviesofthissituationwerecommendatrinitycomprehensivemeasureoftreatment,namely,"buildingseawalltopreventtides-divertingtheHunagheRivertosettleitssedimentloads-raisingtheconstructionalbase".

  • 标签: sea level RISE Bohai BAY COASTAL
  • 简介:Onthebasisofthedressed-atommodel,thegeneralanalyticexpressionsfortheeigenenergies,eigenstatesandtheiropticalpotentialsoftheA-configurationthree-levelatomsystemarederivedandanalysed.Fromthecalculationofdipolematrixelementofdifferentdressedstates,weobtainthespontaneous-emissionratesinthedressed-atompicture.Wefindthatourgeneralexpressionsofopticalpotentialsforthethree-leveldressedatomcanbereducedtothesameasonesinpreviousreferencesundertheapproximationofasmallsaturationparameter.Wealsoanalysethedependencesoftheopticalpotentialsofathree-level^85Rbatomonthelaserdetuningandthedependencesofspontaneous-emissionratesontheradialpositioninthedarkhollowbeam,anddiscusstheprobability(population)evolutionsofdressed-atomiceigenstatesinthreelevelsinthehollowbeam.

  • 标签: 原子物理学 解析解 三层修正原子模型 原子光学 铷原子 原子本征态
  • 简介:Knowledgeabouthumanbeingsisanintegralpartofanyintelligentagentofconsiderablesignificance.Delimiting,modelingandacquiringsuchknowledgearethecentraltopicsofthispaper.Becauseofthetremendouscomplexityinknowledgeofhumanbeings,weintroduceatop-levelontologyofhumanbeingsfromtheperspectivesofpsychology,sociology,physiologyandpathology.Thisontologyisnotonlyanexplicitconceptualizationofhumanbeings,butalsoanefficientwayofacquiringandorganizingrelevantknowledge.

  • 标签: 计算机心理学 人类生存本体论 知识获取
  • 简介:Thispaperstudiesthelinkageproblembetweentheresultofhigh-levelsynthesisandback-endtechnology,presentsamethodofhigh-leveltechnologymappingbasedonknowledge,andstudiesdeeplyallofitsimportantlinkssuchasknowledgerepresentation,knowledgeutilityandknowledgeacquisition.Itincludes:(1)presentakindofexpandedproductionaboutknowledgeofcircuitstructure;(2)presentaVHDL-basedmethodtoacquireknowledgeoftechnologymapping;(3)providesolutioncontrolstrategyandalgorithmofknowledgeutility;(4)presentahalf-automaticmaintenancemethod,whichcanfindredundanceandcontradictionofknowledgebase;(5)presentapracticalmethodtoembedthealgorithmintoknowledgesystemtodecreasecomplexityofknowledgebase.Asystemhasbeendevelopedandlinkedwiththreekindsoftechnologies,soverifiedtheworkofthispaper.

  • 标签: HIGH-LEVEL synthesis TECHNOLOGY MAPPING VHDL HIGH-LEVEL
  • 简介:本文阐述了基于形变模型(DeformableModels)的LevelSet分割方法的基本原理及其特点,介绍了在图像域的实现方法,实现并改进了基于该模型的NarrowBand快速算法.该算法的基本流程是:先在需要分割的目标内或外给定一封闭的初始曲线,通过Gaussian滤波后计算图像的梯度,最后通过NarrowBand算法完成轮廓线的抽取.该算法应用于医学CT/MRI影像以及显微图像的目标分割中,取得了较好的实验结果,证明该方法非常适合于对具有分支、突触以及拓扑结构变化的目标进行快速精确分割.文中给出了算法实现的基本流程、相关参数的选取准则和部分实验结果.实验发现算法中涉及的参数对提取的轮廓线的精确和光滑程度有较大影响.

  • 标签: 形变模型 Level SET NARROW Band算法 图像分割
  • 简介:随着布线系统向万兆网络应用发展,现场测试仪需要支持高频的扫描以满足诸如ISO-F600MHz的测试标准或者6a类625MHz的应用标准。在这些更高频率的情况下,测试信号接近电缆标准的频率极限,因此可能使得测量信号低于测试仪器本身产生的噪声信号。

  • 标签: 布线系统 LEVEL 测试仪 网络分析仪 永久性链路
  • 简介:StandardmetabolicratesofSchlegelsblackrockfishwithdifferentbodyweightsaredeterminedinlaboratorybyusingtheflow-throughrespirometerat11.2℃,14.7℃,18.0℃and23.6℃.Theresultsindicatethatthestandardmetabolicratesincreasewiththeincreaseofbodyweightatdifferenttemperatures.RelationshipbetweenthemcouldbedescribedasRs=aInWb.Themeanofstandardmetabolicrateissignificantlydifferentamonggroups,butthebvaluesarenot.Thestandardmetabolicratesofamendedstandardbodyweightsdecreasewiththeincreaseoftemperature,andthemeanofstandardmetabolicrateisalsosignificantlydifferentamonggroupswhenthestandardbodyweightsare48.6g,147.9g,and243.1g.RelationshipbetweenthemcouldbedescribedasRsw=me-bT.Therelationsofstandardmetabolicrate(Rs)orrelativemetabolicrate(Rs)tobodyweightandtemperatureyieldthefollowingequations:Rs=1.160W0.752e-9.494/7andRs1=1.160W0.254e-9.494/7.

  • 标签: 新陈代谢 黑岩鱼 体重 温度
  • 简介:应用根系喷雾箱(RootMistingChamber,RMC)形成的5次干旱循环,通过PV曲线的水分参数研究了多重复干旱循环对1年生北美短叶松PinusbanksianaLamb.和黑云杉Piceamariana[Mil]B.S.D.苗木耐旱特性的影响.结果表明,生长在干旱沙地的深根性树种北美短叶松,其丧失膨压的相对含水量(8076%~8141%)和水势((-174±010)MPa)都比较低,细胞弹性模量(573~652MPa)比较小,而束缚水含量(5272%~5426%)比较高,显示出它固有的强有力的忍耐脱水能力;但是在多重复干旱循环下它却不能进一步调节其渗透势和细胞弹性,而且其束缚水含量和吸水能力也有所下降.生长在湿润地区的浅根性树种黑云杉,虽然其丧失膨压的相对含水量(8353%~8550%)和水势((-168±003)MPa)比较高,细胞弹性模量(862~964MPa)比较大,束缚水含量(3644%~4605%)比较低,显示出较弱的耐旱能力,但是它在多重复干旱循环下却能提高其束缚水含量以改善原生质耐旱程度,降低细胞弹性以提高其吸水能力,调节其渗透势以保持较高的膨压.这表?

  • 标签: 北美短叶松 黑云杉 耐旱性 PV曲线 渗透调节 细胞弹性模量
  • 简介:Besidesofconsideringofthemaximizationofpublicinterest,thebenefitofpassengersandrailwayenterprisesarebothconsideredandabi-levelprogrammingapproachispresentedinordertoseektheoptimalrailwaypassenger-ticketpricingstrategyundertheconditionofcompetitionamongdifferentintercitytrafficmodes.Therearetwobi-levelprogrammingproblems.Onebi-levelproblemistodeterminearailwaypassenger-ticketaveragepricestrategytomeet.theobjectiveofmaximizingtheconsumersurplusundertheconditionofmulti-modaltransportationwithelasticdemand.Theotherbi-levelproblemistodeterminethepriceofdifferentkindsofthepassengertrainstomeettheobjectiveofmaximizingtherailwayrevenuewheretheaveragepriceandthedemandoftherailwayisdetermined.Aheuristicalgorithmforthetwobi-levelprogrammingmodelsisalsoproposed.Finallytheapplicationsofthemodelanditsalgorithmareillustratedwithanumericalexample.

  • 标签: 票价 平衡模型 二值编程 灵敏度 铁路运输
  • 简介:我们在场在多重洞纠缠域的一个计划。我们的计划基于Ξ-的反响的相互作用与洞地forprecalculated相互作用时间打三水平的原子,它使我们能产生量entangledGreenberger-Horn-Zeilinger(GHZ)在多重洞的地的状态。原则上,计划能也被概括产生N聚会GHZ状态。要求的试验性的技术在能在建立的微波洞证完被获得的范围以内。

  • 标签: GHZ态 空穴 三平层原子 原子物理学
  • 简介:Storingthewholedatabaseinthemain-memoryisacommonmethodtoprocessreal-timetransactioninreal-timedatabasesystems.TherecoverymechanismofMain-memoryReal-timeDatabaseSystems(MMRTDBS)shouldreflectthecharacteristicsofthemain-memorydatabaseandreal-timedatabasebecausetheirstructuresarequitedifferentfromotherconventionaldatabasesystems.Inthispaper,therefore,weproposeamulti-levelrecoverymechanismformain-memoryreal-timedatabasesystemswithExtendibleChainedBucketHashing(ECBH).Owingtotheoccurrenceofreal-timedatainreal-timesystems,weshouldalsoconsideritinourrecoverymechanism.Accordingtoourperformancetest,thismechanismcanimprovethetransactionconcurrency,reducingtransactions'deadlinemissingrate.

  • 标签: 实时数据库 无用数据 存储器 多级数据恢复
  • 简介:Thedynamicalframeworkofthenine-levelversionoftheIAPAGCMispresentedinthispaper.Theemphasisofthemodel’sdescriptionisputonthefollowingtwoaspects:(1)Amodel’sstandardatmosphere,whichisasatisfactoryapproximationtotheobservedtroposphereandlowerstratospherestandardatmosphere,isintroducedintotheequationsofthemodeltopermitamoreaccuratecalculationoftheverticaltransportterms,especiallynearthetropopause;(2)Theverticallevelsofthemodelarecarefullyselectedtoguaranteeasmoothdependenceoflayerthicknessuponpressureinordertoreducethetruncationerrorinvolvedintheunequalintervalverticalfinite-differencing.Fortestingthemodel,twokindsoflinearbaroclinicRossby-Haurwitzwaves,oneofwhichhasadynamicallystableverticalstructureandtheotherhasarelativelyunstableone,areconstructedtoprovideinitialconditionsfornumericalexperiments.Thetwowaveshavebeenintegratedformorethan300daysand100daysre

  • 标签: satisfactory TRUNCATION dynamically GUARANTEE troposphere UNSTABLE