简介：Foghasrecentlybecomeafrequenthigh-impactweatherphenomenonalongthecoastalregionsofNorthChina.Accuratefogforecastingremainschallengingduetolimitedunderstandingofthepredictabilityandmechanismoffogformationassociatedwithsynoptic-scalecirculation.Onefrequentsynopticpatternoffogformationinthisareaisassociatedwithcoldfrontpassage(cold-frontsynopticpattern,CFSP).ThispaperexploredthepredictabilityofatypicalCFSPfogeventfromtheperspectiveofanalyzingkeycharacteristicsofsynoptic-scalecirculationdeterminingfogforecastingperformanceandthepossiblemechanism.TheeventwasensembleforecastedwiththeWeatherResearchandForecastingmodel.Twogroupsofensemblememberswithgoodandbadforecastingperformancewereselectedandcomposited.Resultsshowedthatthepredictabilityofthiscasewaslargelydeterminedbythesimulatedstrengthsofthecold-frontcirculation(i.e.,troughandridgeandtheassociatedsurfacehigh).Thebad-performingmemberstendedtohaveaweakerridgebehindastrongertrough,andassociatedhigherpressureoverlandandaweakersurfacehighoverthesea,leadingtoanadverseimpactonstrengthanddirectionofsteeringflowsthatinhibitwarmmoistadvectionandenhancecolddryadvectiontransportedtothefocusregion.Associatedwiththiscolddryadvection,adversesynopticconditionsofstratificationandmoistureforfogformationwereproduced,consequentlycausingfailureoffogforecastinginthefocusregion.Thisstudyhighlightstheimportanceofaccuratesynoptic-scaleinformationforimprovedCFSPfogforecasting,andenhancesunderstandingoffogpredictabilityfromperspectiveofsynoptic-scalecirculation.

简介：Thecommoncoldistheworld'smostwidespreadillness,whichisaplague(疫病)thatfleshreceives.

简介：Currently,theworldeconomyisundergoingprofoundadjustmentintheaftermathofglobalfinancialcrisis,assumingamediocresituationoflowgrowth-rate,lowinflationandhigh-debt.Atthesametime,theeconomicperformanceofChinashowssomenewsituationsandfeatures:somemajorperiodicchangesgraduallyemerge,thecontradictionandproblemofimbalanceand

简介：某些动词如:catch,have,get.take等与cold连用,表示感冒、伤风、着凉之意。有时cold前带a.有时不带a.有时可带可不带.为了弄清楚这些关系,现归纳如下。一、动词have,get与cold连用,要加a.表示状态.可与表示延续性时间状语连用。例如:1)Hehashad(got)acoldfordays.2)I’vegot(had)acoldsincemyarrival.二、动词take与cold连用,不加a。例如:1)Youusedtotakecold,usedn’tyou?2)XiaoLiuisn’tstrongenough.Sheeasilytakescolds三、动词catch与cold连用,a可有可无。例如:Putonyourcoat,oryou’llcatch(a)cold.

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简介：鉴于在在波浪前面构造方法的非常规的四边的格子和常规矩形格子节点之间的相对的放问题，有放方法的四个格子的具体实现问题(向量十字产品判断，角度和，交叉点，并且签署比较算法)在通常在计算机被使用的波浪前面建设，图形在这被比较并且分析纸。在在波浪前面建设在非常规的四边的格子和常规矩形格子节点之间放的亲戚的实现基于地点方法，向量十字产品判断方法更快的计算例子表演和比另外的方法精确的更多的稳定性分析。它为移植和demigration的下一步提供精确格子点属性价值。

简介：Thisletterpresentsafacenormalizationalgorithmbasedon2-Dfacemodeltorecognizefaceswithvariantposturesfromfront-viewface.A2-Dfacemeshmodelcanbeextractedfromfaceswithrotationtoleftorrightandthecorrespondingfront-viewmeshmodelcanbeestimatedaccordingtothefacialsymmetry.Thenbasedontheinnerrelationshipbetweenthetwomeshmodels,thenormalizedfront-viewfaceisformedbygraylevelmapping.Finally,thefacerecognitionwillbefinishedbasedonPrincipalComponentAnalysis(PCA).Experimentsshowthatbetterfacerecognitionperformanceisachievedinthisway.

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简介：Whilethehumanracehasaccomplishedmanyamazingfeats,curingthecommoncoldhasnotbeenoneofthem.Evenafterhundredsofyearsofresearch,scientistsstillcannotstompoutthetinybug.

简介：日本松锯工，Monochamusalternatus，一个重要的松森林害虫和向量正在播送松枯萎原因消瘦的线虫枯萎疾病。在秋天，冬季和春天的低温度经常差别影响M的死亡。alternatus幼虫。在这篇论文，我们主要比较了死亡并且从不同季节的幼虫的冷变硬的差别，基于supercooling点(SCP)和个人结冰的累积概率(CPIF)。从秋天，冬季和春天季节的幼虫的冷变硬大部分是不同的。在秋天和春天幼虫的死亡和CPIF之间的关联在天1/4上是最高的，并且逐渐地与延长暴露持续时间减少了。这甲壳虫的死亡主要源于在短暴露持续时间结冰。然而，在冬季幼虫的死亡和CPIF之间的关联与延长暴露持续时间逐渐地增加了。死亡主要没源于在长暴露持续时间结冰。秋天幼虫比冬季和春天幼虫更易受影响、能适应。冬季幼虫有一个细微结冰忍耐趋势。我们的研究显示出那M。alternatus在自然选择下面进入了复杂冷变硬的策略。结冰回避是主要策略；与到上面的SCP或<的延长暴露持续时间0pC，寒冷忍耐是更重要的；这被跟随由在严厉冬季期间冻结忍耐。

简介：AnumericalsimulationofatorrentialraineventoccurringintheJiang-HuaiValleyofChinafrom22-24June1999isperformedandanalyzedbyusingthePSU/NCARMM5mesoscalenon-hydrostaticmodel.Thehigh-resolutionmodeloutputdataareutilizedtodiagnosethedoublefrontstructure,andthedistributionsofpotentialtemperature,equivalentpotentialtemperature,andspecifichumidityinthevicinityoftheMeiyuFrontSystem(MYFS)intheJiang-HuaiValley.TheresultsshowthatboththepotentialtemperaturegradientandthespecifichumiditygradienthaveimportantimpactsonthetwostrongequivalentpotentialtemperaturegradientzonesassociatedwiththedoublefrontstructureoftheMYFS,butthelatter(moisturegradient)ismoreimportant.Inaddition,thetendencyequationofspecifichumiditygradientistheoreticallyderived.Itshowsthatvariationsofthespecifichumiditygradientarerelatedtotheadvection,convergence/divergence,horizontalandverticalvorticities(secondarycirculation)effectsandthegradientofwatervaporsource/sink.Asanexample,thebudgetofthemeridionalcomponentofthetendencyequationisselectedanddiagnosedbyusingtheabovemodelsimulationdataofthetorrentialrainevent.Itisshownthatthevariationofthespecifichumiditygradientaveragedthroughoutthesimulationismainlycontrolledbytheconvergence/divergenceeffect,thesecondarycirculationeffectassociatedwiththehorizontalvorticities,andthewatervaporsource/sinkeffect.Sincethewatervaporsource/sinkisoftenformedfromthephasechangeprocessesofwatervaporintheairandthusdirectlyassociatedwithcloudandprecipitationmicrophysicsprocesses,thevariationofthespecifichumiditygradientiscloselyrelatedwithcloudandprecipitationmicrophysicsandthedistribution,developmentandevolutionofcloudandrainfallsystems.ThedoublefrontstructureoftheMYFSprovidesanadvantageousenvironmentalconditionforthedevelopmentandmovementofthemesoscaletorrentialrain

简介：阵风前面是一种中央规模和经常引起严肃的地面风和风的微规模的天气现象砍。这份报纸论述一个自动阵风前面鉴定算法。完全，879件雷达卷扫描样品从发生在在2009和2012之间的中国的21个阵风前面天气过程选择了被检验并且分析。阵风前面回响在反射率，速度，和光谱宽度地的统计特征被获得。把特征基于这些，一个算法被设计认出阵风前面并且产生产量产品和量的索引。然后，315件样品被用来证实算法和3个典型案例被分析。主要结论包括：1)因为狭窄的乐队回响紧张在5和30dBZ之间，宽度在2和10km之间，最大的高度是不到4km(89.33%比3km低)，并且长度在50和200km之间。狭窄乐队的回响比它的包围回响高。2)阵风前面介绍一根集中线或风在速度地里砍；当距离向外放射状地增加时，正面的风速度逐渐地减少。光谱阵风前面的宽度大，与87.09%超过4ms<啜class=“a-plus-plus”>1。3)用前面卷扫描取样测试算法的315阵风表明算法是高度稳定的并且成功地认出了277件样品。算法也为小规模或弱的阵风前面工作。4)雷达数据质量在算法上有某些影响。

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简介：Theprincipleofstripwidthmeasuringsystemwithopticalfiberlinkisdescribed,andapracticalmethodisintroduced.

简介：Coldringrollingisanadvancedbutcomplexmetalformingprocessundercoupledeffectswithmulti-factors,suchasgeometrysizesofrollsandringblank,material,formingprocessparametersandfriction,etc.Amongthesefactors,frictionbetweenrollsandringblankplaysanimportantroleinkeepingthestableformingofcoldringrolling.Ananalyticalmethodwasfirstlypresentedforproximatelydeterminingthecriticalfrictioncoefficientofstableformingandthenamethodwasproposedtodeterminethecriticalfrictioncoefficientbycombininganalyticalmethodwithnumericalsimulation.Andtheinfluenceoffrictioncoefficientonthequalityofend-planeandsidespreadofring,rollingforce,rollingmomentandmetalflowcharacteristicinthecoldringrollingprocesshavebeenexploredusingthethreedimensional(3D)numericalsimulationbasedontheelastic-plasticdynamicfiniteelementmethod(FEM)undertheABAQUSsoftwareenvironment,andtheresultsshowthatincreasingthefrictiononthecontactsurfacesbetweenrollsandringblankisusefulnotonlyforimprovingthestabilityofcoldringrollingbutalsoforimprovingthegeometryanddimensionprecisionofdeformedring.

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简介：AdeuteronpossessesacoulombpotentialbarrierwithmaximumUmax≈10^6eV(atro=1.51×10^-13cm)aroundhim.Soprerequisitetodirectcollideandexcitenuclearfusionreactionfortwodeuteronsistopenetratetoallofoppositebarrier.

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