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简介：ThepaperconsiderstheKrylov-LanczosandtheEckhoffapproximationsforrecoveringabivariatefunctionusinglimitednumberofitsFouriercoefficients.Theseapproximationsarebasedoncertaincorrectionsassociatedwithjumpsinthepartialderivativesoftheapproximatedfunction.ApproximationoftheexactjumpsisaccomplishedbysolutionofsystemsoflinearequationsalongtheideaofEckhoff.AsymptoticbehaviorsoftheapproximatejumpsandtheEckhoffapproximationarestudied.Exactconstantsoftheasymptoticerrorsarecomputed.Numericalexperimentsvalidatetheoreticalinvestigations.

简介：到在蝗虫生态学的框架的群居的阶段的从solitarious的转变的详细方面为理解蝗虫阶段polyphenism无疑是很重要的。但由于在在自然学习solitarious阶段的明显的困难，如此的信息从在实验室条件下面执行的研究有限、主要可得到。在当前的学习，我们在模仿了seminatural条件的实验室安装检验了最新孵的蝗虫美女的疏开模式。这没有除控制他们的父母密度以外的美女的以前的操作被执行。我们比较地在在不同范围位于出现以内的栖息上测试了最新孵的美女的空间分发竞技场，和期望的泊松(随机)分发。人工孵化的鱼苗或小鸟被发现在与由随机期望那显著地不同的一个模式在栖息之中分散。不管他们的父母阶段，所有美女的观察分布清楚地是clumped、类似或为群居的蝗虫近到那些期望。看起来而非与一个父母地导出并且预定的阶段新兴，人工孵化的鱼苗或小鸟有一个独立缺省或天生的行为的状态，它反映至少忍耐如果不吸引力到conspecifics。典型阶段行为以后可以在适当环境条件下面变得主导。这些结果在蝗虫阶段转变上暗示新奇观点，它在地条件下面贡献我们蝗虫人群的形成的理解。这些应该为开发蝗虫人口的预防管理策略在任何基本原理被考虑。

简介：Weproposeacatalysis-selectmigrationdrivenevolutionmodeloftwo-species(A-andB-species)aggregates,whereoneunitofspeciesAmigratestospeciesBunderthecatalystsofspeciesC,whileunderthecatalystsofspeciesDthereactionwillbecomeoneunitofspeciesBmigratingtospeciesA.MeanwhilethecatalystaggregatesofspeciesCperformself-coagulation,asdothespeciesDaggregates.Westudythiscatalysis-selectmigrationdrivenkineticaggregationphenomenausingthegeneralizedSmoluchowskirateequationapproachwithCspeciescatalysis-selectmigrationratekernelK(k;i,j)=KkijandDspeciescatalysis-selectmigrationratekernelJ(k;i,j)=Jkij.Thekineticevolutionbehaviourisfoundtobedominatedbythecompetitionbetweenthecatalysis-selectimmigrationandemigration,inwhichthecompetitionisbetweenJD0andKC0(D0andC0aretheinitialnumbersofthemonomersofspeciesDandC,respectively).WhenJD0KC0>0,theaggregatesizedistributionofspeciesAsatisfiestheconventionalscalingformandthatofspeciesBsatisfiesamodifiedscalingform.AndinthecaseofJD0KC0<0,speciesAandBexchangetheiraggregatesizedistributionsasintheaboveJD0KC0>0case.

简介：Aneigenvaluemethodconsideringthemembranevibrationofwrinklingout-of-planedeformationisintroduced,andthestressdistributingruleinmembranewrinkledareaisanalyzed.Adynamicanalyticalmodelofrectangularshearwrinkledmembraneanditsnumericalanalysisapproacharealsodeveloped.Resultsindicatethatthestressinwrinkledareaisnotuniform,i.e.itislargerinwrinklingwavepeaksalongwrinklesandtwoendsofwrinkleinverticaldirection.Vibrationmodesofwrinkledmembranearestronglycorrelatedwiththewrinklingconfigurations.Therigidityislargerduetotheheavierstressinthepartofwrinklingwavepeaks.Therefore,wavepeaksarealwayslocatedatthenodelinesofvibrationmode.Thevibrationfrequencyobviouslyincreaseswiththevibrationofwavepeaks.

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简介：Thecorrugatedpackingispronetobreakdowneasily,whichcanaffectthetowerefficiencysubstantially.Itistheinnerenvironmentofthevacuumdistillationtowerincludingthetemperatureandchemicalnatureoffluidthatleadtothepackingdamage.Thetheoreticalanalysisindicatesthatitistheinnermaterialflowofvacuumdistillationtowerthatleadstothevibrationofpacking,whichcanaffectthecorrosionfatigueofpackingsignificantly.Meanwhile,themodalshapeandinherentfrequencyofpackingunderprestresscanbeobtainedbymeansofmathematicalanalysis.Basedonthetwokindsofanalysis,theflowinducedvibrationandcorrosionfatigueareaccountableforthefailureofpacking.

简介：TheheterogeneousnucleationbehaviorsofNH4ClcrystalonaroughchillingsurfaceofaluminumimmergedinNH4Cl-H2Osolutionwereexperimentallyanalyzedandtherelationshipbetweenthesurfaceroughnessandthenucleationsiteselectionbehaviorsonpolishedaluminumsubstratewasinvestigated,anditwasdiscoveredthatthenumberofnucleationsitesdecreasessignificantlywithdecreasingtheroughnessofthepolishedsubstrate.Furthernucleationexperimentswerecarriedoutonchemicallyetchedaluminumsubstratewithregularmicro-morphologyonitssurface.Ithasbeenshownthatboththemicro-morphologyandthewettabilityvarywiththesubstratesurfacepreparedbydifferentetchingprocess.Thepreparedsurfacewithstep-likestructureshasastrongwettabilitywithNH4Cl-70wt%H2OsolutionandthenucleationdensityofNH4Clontheitssurfacesissignificantlyhigherthanthatofthereferencesurfaces,whichshowsthatthegeometricalmorphologyfeatureshaveimportanteffectsonboththewettabilityandthenucleationbehaviors.

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简介：Aluminamagnesiacastablecruciblespecimenswerepreparedusingtabularcorundum(≤5mm),fusedmagnesiapowder(≤0.088mm),fusedspinelpowder(≤0.044mm),andα-Al2O3micropowder(d50≤0.7μm)asmainstartingmaterials,batching,mixing,shaping,anddrying.Slagresistancewasdeterminedbystaticcruciblemethodat1600℃for3hadoptingtwoladleslagswithdifferentbasicities(3.40and1.03).Thecorrosionandpenetrationindexesandmicrostructurecharacteristicsofthespecimensafterslagresistancetestwereanalyzedtostudythecorrosionbehaviorsofthetwoslagstoaluminamagnesiacastables.Theresultsshowthatthecorrosionofthelowbasicityslagtoaluminamagnesiacastablesismuchmoreseriousthanthatofthehighbasicityslagforthattheirreactionswithcastablesformdifferentproducts;forthelowbasicityslag,themulti-phasecoexistenceofCA6andcompoundsofCaO-Al2O3-SiO2inthematerialstogetherwithvolumeexpansioncausedbytheformationofCA6intensifytheslagcorrosionandpenetration;forthehighbasicityslag,thereactionbetweenslagandcastablesgeneratesaCA2denselayerandalargeamountofin-situMAintheinterface,reducingtheslagcorrosiontothematerialseffectively.

简介：ApreliminarystudywasmadeontheantibacterialbehaviorofanewlydesignedCu-bearingtype200stainlesssteelbydifferentmethodsincludingVickershardnessmeasurement,electrochemicaltestandantibacterialtest.TheresultsshowedthatCu-richprecipitationscausedbythesaturatedCuinthesteelmatrixwasnotonlyacrucialfactorforitsexcellentantibacterialcapability,butalsoforitsequivalentcorrosionresistanceasgoodasthecommercialtype200stainlesssteel.

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简介：这份报纸在陶艺和脱臼包括阶段转变为无弹性的材料行为的纹理粗糙的原子论的模拟论述新方法论在金属的调停的粘性。方法论联合平衡方程和一个修改有限元素方法的原子论的明确的表达。与显著地自由的更少度比那些一个充分原子论的模型并且没有另外的组成的规则但是interatomic力量地，新纹理粗糙(CG)方法被显示在预言材料的非线性的组成的回答并且也复制象阶段转变那样的原子规模的现象可行(在硅和脱臼成核和移植，脱臼环的形成和在单个水晶的叠的差错带子的钻石-Sn)镍。指导在CG和现在的方法论在没有失去必要原子论的特征，当模特儿和无弹性的材料行为的模拟有效、有希望的相应完整的分子的动力学(MD)模拟表演之间的比较。潜在的应用和CG方法的限制也被讨论。

简介：Veryhighcyclefatigue(VHCF)behaviorsofbridgesteel(Q345)weldedjointswereinvestigatedusinganultrasonicfatiguetestsystematroomtemperaturewithastressratioR=-1.Theresultsshowthatthefatiguestrengthofweldedjointsisdroppedbyanaverageof60%comparingtothebasemetalandthefatiguefailurestilloccurredbeyond10~7cycles.Thefatiguefractureofweldedjointsinthelowcycleregimegenerallyoccurredatthesolderwhileattheheat-affectedzone(HAZ)intheveryhighcycleregime.Thefatiguefracturesurfacewasanalyzedwithscanningelectronmicroscopy(SEM),showingweldingdefectssuchaspore,micro-crackandinclusionwerethemainfactorsondecreasingthefatiguepropertiesofweldedjoints.Theeffectofweldingdefectsonthefatiguebehaviorsofweldedjointswasdiscussedintermsofexperimentalresultsandfiniteelementsimulations.

简介：HightemperatureoxidationbehavioroftwokindsofnitridebondedSiCbasedrefractorieswasinvestigatedat11001500℃bymeansofX-raydiffractometer,scanningelectronicmicroscopyandthermogravimetry.Theresultsshowthat:(1)withthetemperatureincreasing,theoxidationmassincrementrateofthespecimenincreasesfirstandthendecreases,andoxidationpassivationoccurs;(2)theoxidationresistanceofSiAlONbondedSiCrefractoriesissuperiortothatofSi3N4bondedSiCrefractories;(3)hightemperatureoxidationresultsintheincreaseofcompressivestrengthatroomtemperatureofSiCbasedrefractoriescomparedwithspecimenbeforeoxidation;thecompressivestrengthofSiAlONbondedSiCspecimensoxidizedathightemperaturesdecreaseswiththeincreaseofthetemperatureasaresultofformationandburstofsurfacebubble,whilethedecreaseofcompressivestrengthofSi3N4bondedSiCspecimensoxidizedathightemperaturesisowingtotheincreaseoftheconsistencyofnet-likecrackassociatedwithcristobalitetransformationduringcooling.

简介：YB/T384-20111ScopeThisstandardspecifiestheclassification,technicalrequirements,testmethods,qualityappraisalprocedures,packing,marking,transportation,storage,andqualitycertificateofsilicarefractorymortars.Thisstandardisapplicabletosilicarefractorymortarsforliningsilicabricks.2NormativeReferencesThefollowingdocumentsareessentialtotheapplicationofthisstandard.Fordatedreferences,onlytheeditioncitedapplies.

简介：Time-temperaturesuperpositionprinciple(TTSP)wasusedtoexaminedynamicviscoelasticpropertiesofChineseFir(Cunninghamialanceolata)woodatanextremelylowmoisturecontent(0.6%).Storagemodulusandlossfactordatawereobtainedatdifferentconstanttemperaturesrangingfrom25℃to150℃infrequencymultiplexingexperiments(0.1-20Hz).Allviscoelasticcurvesatothertemperatureswereshiftedalongthelog-frequencyaxistosuperimposethemonareferencetemperature(i.e.135℃inthisstudy)curve.Theextendedstoragemodulusandlossfactorisothermalmastercurveswereoverawiderangeoffrequency.TheshiftfactorsweredeterminedtobeafunctionoftemperatureandfittedintotheArrheniusequationwiththeleastsquaresmethod.TheresultsshowedthatthestoragemodulusdatawereexcellentlyfittedintotheArrheniusmodel,indicatingthevalidityofthemodeltocharacterizethedynamicstiffnessbehaviorofdrywoodintherangeof25-150℃usingtheTTSP.However,thetime-temperatureequivalencewasnotabletopredictthedampingproperties.

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简介：这篇文章的作者学习ut=div的起始边界的值问题的弱解决方案的存在和唯一((|u|+d0)|u|p(x，t)2u)+f(x，t)(0<<2)。

简介：在这，纸在tribological性质上各种各样的注射塑造完成参数超离频分子的重量聚乙烯(UHMWPE)被调查。tribological性质喜欢磨擦的系数并且穿率从在实验室被设计并且制作的新潮的模拟器的试验性的结果被获得。牛的浆液在这研究被用作润滑剂。另外，标本的坚硬也也被调查。塑造为这研究变化了的参数的注射是融化温度，注射速度和压缩时间。结果证明接触装载并且融化温度主要被影响UHMWPE的tribological行为。A穿机制地图被开发学习主导穿影响UHMWPE的wear行为的机制。SEM被采用学习用坏UHMWPE的形态学。主导穿通过我们的学习被统治的机制正在熨的、抓的、耕作、塑料变丑，和疲劳穿。