学科分类
/ 25
500 个结果
  • 简介:新对光反应变色bisphenoxynaphthacenequinone混合物,6,6素数-[1-methylethylidenebis(4,1-phenyleneoxy)]二度(5,12-naphthacenequinone)(1),被一个二拍子的圆舞方法综合,即,6的合成[4-(2-(4-hydroxyphenyl)异丙基)含苯氧基)从6-chloro-5的-5,12-naphthacenequinone(2),12-naphthacenequinone(3)和bisphenol--A,和在DMF/丙酮的化合物2的进一步的反应面对无水的碳酸钾和碘化钾混合了溶剂。粗略的产品在一种precipitate形式被获得并且能被再结晶容易净化。溶剂作文在第二步在猛抛的粗略的产品的收益上标记影响。(编辑作者摘要)3个裁判员。

  • 标签:
  • 简介:Afamilyofunconditionallystabledirectintegrationalgorithmwithcontrollablenumericaldissipationsisproposed.Thenumericalpropertiesofthenewalgorithmsarecontrolledbythreeparametersα,βandγ.Bytheconsistentandstabilityanalysis,theproposedalgorithmsachievethesecond-orderaccuracyandareunconditionallystableundertheconditionthatα≥-0.5,β≤0.5andγ≥-(1+α)/2.Comparedwithotherunconditionallystablealgorithms,suchasChang’salgorithmsandCRalgorithm,theproposedalgorithmsarefoundtobesuperiorintermsofthecontrollablenumericaldampingratios.Theunconditionalstabilityandnumericaldampingratiosoftheproposedalgorithmsareexaminedbythreenumericalexamples.Theresultsdemonstratethattheproposedalgorithmshaveasuperiorperformanceandcanbeusedexpedientlyinsolvinglinearelasticdynamicsproblems.

  • 标签: DIRECT INTEGRATION method unconditional STABILITY NUMERICAL
  • 简介:Inthispaper,analmostP-stabletwo-stepsixth-orderHybridmethodwithphase-lagoforderinfinityandaclassexpliciteighth-orderObreckoffmethodswithphase-lagoforder10-24aredevelopedforthenumericalintegrationofthespecialsecond-orderperiodicinitial-valueproblems.Thesemethodshavetheadvantageofhigheralgebraicorderandconsiderablysmallerphase-tagcomparedwithsomemethodsin[1-6].Numericalexamplesindicatethatthesenewmethodsaremoreaccuratethanmethodsdevelopedby[1-6].

  • 标签: second order periodic initial-value problems interval
  • 简介:Inthisstudy,atwo-stepheatingprocessisintroducedfortransientliquidphase(TLP)diffusionbondingforsoundjointswithT91heatresistantsteels.Atfirst,ashort-timehighertemperatureheatingstepisaddressedtomelttheinterlayer,followedbythesecondsteptocompleteisothermalsolidificationatalowtemperature.Themostcriticalfeatureofournewmethodisproducinganon-planarinterfaceattheT91heatresistantsteelsjoint.WeproposeatransitionalliquidphasebondingofT91heatresistantsteelsbythisapproach.Sincejointmicrostructureshavebeenstudied,wetestedthetensilestrengthtoassessjointmechanicalproperty.Theresultindicatesthatthesolidifiedbondmaycontainaprimarysolid-solution,similarcompositiontotheparentmetalandfreefromprecipitates.Jointtensilestrengthofthejointisnotlowerthanparentmaterials.Jointbend'sstrengthsareenhancedduetothehighermetal-to-metaljunctionproducinganon-planarbondlines.Nevertheless,thetraditionaltransientliquidphasediffusionbondingproducesplanarones.Bondingparametersofnewprocessare1260℃for0.5minand1230℃for4min.

  • 标签: 液相扩散焊 T91钢 工艺 焊接接头 瞬时 等温凝固
  • 简介:Anewtechnology,thetwo-steptransientliquidphasediffusionbonding(TLP-DB)technologyforcobalt-basedK640superalloy,wasinvestigated.Themethodconsistsofashort-timehightemperatureheatingtomeltinterlayerfollowedbyisothermalsolidificationofliquidphaseatalowertemperaturethanthatoftheconventionalTLP-DB.Theresultindicatesthatthetwo-stepTLP-DBcanreliablyproduceanidealjointwithuniformchemicalcomposition,whichissuperiortothejointweldedbyconventionalTLP-DBinmicrostructureandmechanicalproperties.Bondingparametersofnewprocessare1250℃for0.5hand1180℃for3h.Thehigh-temperaturetensilestrengthofthejointbytwo-stepTLP-DBreaches74%ofthatofthebasematerialonanequalbasis,butthehigh-temperaturetensilestrengthofthejointbyconventionalTLP-DBisonly58%ofthatofthebasematerial.

  • 标签: 钴基耐高温合金 两步过渡液相扩散焊 中间层合金 硬度
  • 简介:A双层TiO2nanotube数组被Ti陪衬的二拍子的圆舞阳极化在不同电解质形成。首先,在0.5wt%HF的Ti被阳极化形成薄nanotube层。以后,第二阳极化在formamide被进行基于电解质,它允许在第一下面直接成长的nanotube的第二层。从FESEM调查,我们发现第二层的厚度对应于阳极化时间,增加哪个将导致在第一层上的过多的蚀刻。第一层在阳极化过程期间保护了更低的免受氟化物腐蚀的伤害。双层TiO2nanotube数组没在甲基橘子降级实验显示出利益到photodegradation效果。

  • 标签: 二氧化钛纳米管 阳极氧化 光催化活性 紫外光 纳米管阵列 TIO2
  • 简介:TheDalianInstituteofChemicalPhysics(DICP)ofCAShasdevelopedthetechnologyformanufactureofDMEthroughtwo-stepdehydrationofmethanoland

  • 标签: DME 催化剂 石油加工 炼油过程
  • 简介:Thesatelliteremotesensinghasbecomeapromisingtechniquefordetectingearthquakeandfaultactivities.Butitisstillverydifficulttoexactlyextracttheearthquakeanomalyfromthecomplicatedremotesensinginformation.Thispaperpresentedatwo-stepmethodtoextracttheseismicmicrowaveradiationanomalyrelatedwithearthquake,whichcouldeliminatethestableinfluenceofgeography,terrain,coversphereandseasons,aswellastherandominfluenceofweather.Furthermorethetwo-stepmethodwasappliedtoanalyzetheanomalyofWenchuanearthquakebasedonthedataofAMSR-E.Microwaveradiationanomalieswereeffectivelydetectedrelatedtothemainshockandaftershocks.Theextractedmicrowaveradiationvariationshowedgeneralfeaturesofthree-stage:thepositiveradiationanomalyappearedaroundtheepicenterinthefirststage,quietvariationinthesecondstage,andabnormalareagraduallymovedtotheepicenterinthethirdstage.AfterthemainshockthemicrowaveradiationanomaliesdistributedalongtheLongmenshanfaults,andtheepicentersofaftershockswerecoincidentwiththeanomalyareainspace.

  • 标签:
  • 简介:基于镍的复合的层被阳极化在五分钱板上准备在一75?wt%H3PO4答案包含NH4F。这层然后被galvanostatic控告/解除(GCD)对待直到黑外部层被分开,留下象为supercapacitors的没有文件夹的电极材料的镍板上的一部电影。这部电影由Ni组成的微结构描述表演(哦)2和NiO,和没有氟化物在同样获得的电影被发现。电气化学的测试证明这个没有氟化物的电影电极展出954的一个高电容?F圆形的二色性(CD)系列和polyacrylamide胶化电气泳动(页)。当聚合物支架和金属建筑群作为催化活跃中心工作了,BSA服务了。当到BSA的转变金属离子建筑群的有约束力的比率是5:1时,结果证明BSA的结构仍然保持未改变。而且,清除superoxide一??

  • 标签: 超级电容器 电化学制备 复合膜 镍板 无氟 镍基
  • 简介:在这篇论文,为解决单个延期的二拍子的圆舞连续性Runge-Kutta(TSCRK)方法的一个班微分方程(DDE)被介绍。方法被给的这的数字稳定性的分析。我们考虑二个不同盒子:(ⅰ)τ≥h,(ⅱ)τ

  • 标签: 时滞微分函数 稳定性 连续性 RUNGE-KUTTA方法
  • 简介:在原处,有在硅石矩阵的柳酸(柳安)的铽建筑群的合成被一个二拍子的圆舞大音阶的第五音胶化过程做。有柳酸的铽建筑群在大音阶的第五音胶化被形成导出硅石胶化,并且由光刺激系列证实了并且红外线(红外)系列。作为与纯铽建筑群粉末相比,包含铽建筑群的硅石胶化展出它的典型排放并且为纯建筑群比那介绍更长的荧光一生。复杂包含硅石胶化的光性质被调查,与那些相比,两个,铽做了硅石胶化和纯复杂粉末。导致上述结果的原因也被讨论。(编辑作者摘要)7个裁判员。

  • 标签:
  • 简介:Temperature-dependentphotoluminescencecharacteristicsoforganic-inorganichalideperovskiteCH3NH3PbI3-xClxfilmspreparedusingatwo-stepmethodonZnO/FTOsubstrateswereinvestigated.Surfacemorphologyandabsorptioncharacteristicsofthefilmswerealsostudied.Scanningelectronmicroscopyrevealedlargecrystalsandsubstratecoverage.Theorthorhombic-to-tetragonalphasetransitiontemperaturewas140K.Thefilms’excitonbindingenergywas77.6±10.9meVandtheenergyofopticalphononswas38.8±2.5meV.TheseresultssuggestthatperovskiteCH3NH3PbI3-xClxfilmshaveexcellentoptoelectroniccharacteristicswhichfurthersuggeststheirpotentialusageinperovskitebasedoptoelectronicdevices.

  • 标签: 金属卤化物 有机-无机 光致发光 钙钛矿 氧化锌 两步法
  • 简介:Thispaperpresentsatwo-stepexplicitmethodoforderfourforsolvingaclassoflinearperiodicinitialvalueproblems.Ateachcomputationalstep,onlytworightfunctionevaluationsandonederivativeevaluationareemployed.Basingonaspecialvectoroperation,themethodcanbeextendedtothevector-applicableinmulti-dimensionalspace.

  • 标签: 线性周期初值问题 二步显式方法 特征方程 矢量积
  • 简介:Weintroduceaone-stepimplicititerativemethodfortwofinitefamiliesofasymp-toticallynonexpansivemappingsinahyperbolicspaceanduseittoapproximatecommonfixedpointsofthesefamilies.Theresultspresentedinthispaperarenewinthesettingofhyperbolicspaces.Ontop,thesearegeneralizationsofseveralresultsinliteraturefromBanachspacestohyperbolicspaces.Attheendofthepaper,wegiveanexampletovalidateourresults.

  • 标签: UNIFORMLY convex hyperbolic space ASYMPTOTICALLY NONEXPANSIVE
  • 简介:我的儿子陈陈,2岁半,语言方面发展得不错。他能够自如地和大人交流,自己能够说出完整的句子,也会用一些连词构成比较复杂的句子,有时还可以简短地描述一件事情的发生,发音口齿也比较清晰。

  • 标签: STEP STEP 句子
  • 简介:想试试“飞檐走壁”的感觉吗?拿一条绳子,拴在两棵树上就能体验。这种名为“走扁带”的运动正在兴起,不仅能练出超级平衡感,还能瘦身燃烧脂肪,提高柔韧性。走扁带虽然不同于走钢丝,但稍加练习也能掌握技巧。冬天气温低,在室外运动很冻手,来走走扁带,它可谓是减压、锻炼两全其美。

  • 标签: STEP 平衡感 柔韧性 运动