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简介：Solventextractionofpalladium(Ⅱ)fromhydrochloricacidsolutionwith2-n-octyl-4-isothiazolin-3-one(OIT)/cyclohexanewasstudied.Effectsofdifferentparametersonextractionefficiencywereevaluated.99.96%and98.26%palladium(Ⅱ)couldbeeffectivelyextractedwith0.018mol·L-1OIT/cyclohexaneof0.1and4.0mol·L-1HClmedium,respectively.Nonpolarsolventandlowaciditycouldimprovetheextractingefficiency,andsuccessfullystrippalladium(Ⅱ)fromtheloadedorganicphasewasachievedwith0.5mol·L-1(NH2)2CSsolution.ItwasproposedthattheextractionofPdcomplexesfromHClmediumproceededthroughtheionassociationmechanismbyslopemethod,NMRandFT-IRspectra.

简介：AnewtypeofcomplexsolidsuperacidcatalystWO3-ZrO2-SO42-withanacidstrengthH0≤-16.04waspreparedbykneadingZr（OH）4oramorphousZrO2withtungsticacid（H2WO4）（W/Zr=0.15）,followedbyexposingthiscomplexhydroxidesto0.5tool/LH2SO4,calcininginairat700～800℃for3h.ThiscatalystpossessesbothstrongBronstedacidityandstrongLewisacidityexperimentallyshowedbyIRobservationofpyridineabsorbedonit.XPSandAEStechniqueswereemployedtoexaminethevalencestatesoftungsten,zirconium,sulfurandtheirinteractions.Thestructureofsulfurspecieswasstudiedbyinfraredspectroscopyandastructuremodelofactivesitewasproposedupontheseresults.

简介：散热问题已成为电子设计者面前的最大挑战之一,研究开发导热性好并且与铜箔（铜线路）间有较好的粘结强度和刚度的绝缘层材料对HDI电路板的应用具有重要意义。随着2008年欧盟RoHS指令的逐步开始实施,现有电子元器件含溴阻燃体系逐渐禁用,因此无卤2W导热率导热膜开发意义重大。

简介：１ＩｎｔｒｏｄｕｃｔｉｏｎＩｔｈａｓｂｅｅｎｄｅｍｏｎｓｔｒａｔｅｄｔｈａｔｓｐｉｎｅｌｓｔｒｕｃｔｕｒｅｌｉｔｈｉｕｍｍａｎｇａｎｅｓｅｏｘｉｄｅｉｓｔｈｅｍｏｓｔｐｒｏｍｉｓｉｎｇｃａｔｈｏｄｅｆｏｒ“ｌｉｔｈｉｕｍｉｏｎ”ｂａｔｅｒｉｅｓｂｅ...

简介：通过原位生成反应，采用Cu-3．4％Ti和Cu-0．7％B中间合金，利用快速凝固技术制备纳米TiB，颗粒增强块体Cu—Ti合金，然后对合金在900℃进行热处理l～10h。高分辨透射电镜（HRTEM）观察表明，在铜熔体中，Ti和B通过原位反应生成初始纳米TiB2颗粒和TiB晶须，TiB晶须的生成会导致TiB2颗粒粗化。初始TiB2颗粒沿晶界分布，会阻碍晶粒在高温下的生长。在对合金进行热处理时，晶粒内的Ti和B原子通过扩散反应生成二次TiB2颗粒。对合金热处理前后的导电率和硬度进行测试。结果显示，生成的二次TiB2颗粒能够延缓合金在高温下硬度的下降，合金的电导率和硬度随着热处理时间的延长而增加，在处理8h时分别为33．5％IACS和HVl58。

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简介：Fe(OH)3precursorsolwaspreparedbyasol-gelmethod.Theprecursorsolwasdippedontotheabsorbentcotton,andgelwasformedontheabsorbentcottontemplateafterthevolatilizationofmoisture.Fe2O3microtubulesweresynthesizedaftertheprocessofself-propagationorcalcination.Thephase,morphology,andparticlediameterofthesampleswereexaminedbyX-raydiffraction(XRD)andscanningelectronmicroscopy(SEM),andthemagneticpropertiesofthesamplesweremeasuredusingavibratingsamplemagnetometer(VSM).TheexternaldiametersofFe2O3microtubulesrangedbetween8and13μm,andthewallthicknessesrangedbetween0.5and2μm.ThetypeofthecalcinationmethodplaysasignificantroleindevelopingtheFe2O3phaseandthevariationinthemagneticpropertiesinthesol-geltemplatecomplexingmethod.γ-Fe2O3wassynthesizedbyaself-propagationmethod.However,α-Fe2O3wassynthesizedaftercalcinationat400°Cfor2h.Thecoercivityofthesamplessynthesizedbycalcinationat400°Cfor2hafterself-propagationwasfoundtoincreasesignificantly,therebypresentinghardmagneticproperties.

简介：在经过NaOH-HCl预处理的镍钛合金基体上,采用溶胶-凝胶法制备纳米多孔TiO2薄膜;当涂覆一层致密内膜和一层多孔外膜时,可得到无裂纹的薄膜（试样TC1＋1）。X射线衍射表明,TiO2薄膜由锐钛矿组成,在热处理的基体中还检测到少量的Ni4Ti3相。X射线光电子谱分析表明,试样TC1＋1的TiO2薄膜完全覆盖了镍钛合金基体。试样TC1＋1的表面亲水,接触角约为20°,紫外光照处理15min后接触角降低到（9.2±3.2）°。在0.9%NaCl溶液中的动电位极化实验表明,试样TC1＋1的耐蚀性高于抛光的镍钛合金试样的。

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简介：采用化学平衡模拟软件GEMS预测了锌湿法冶金过程中涉及的锌在Zn（Ⅱ）-NH3-H2O和Zn（Ⅱ）-NH3-Cl--H2O体系中的溶解度,并构建了其含锌物种分布图和优势区图。采用平衡实验方法测定了相同条件下锌的溶解度,其结果与预测结果相吻合。含锌物种的分布图和优势区图表明,在弱碱性条件下,2个体系均为以锌氨和羟基锌氨配合物为溶液的主要物种,其中Zn（NH3）24-为主要优势物种;在Zn（Ⅱ）-NH3-Cl--H2O体系中,锌氨氯三元配合物的形成能有效增大锌在中性条件下的溶解度,在该体系中存在Zn（OH）2、Zn（OH）1.6Cl0.4和Zn（NH3）2Cl23种固相,固相产物的形成取决于体系中总锌、总氨和总氯浓度。这些热力学平衡图表明了体系中各种物种之间的相互影响作用,并预测了总氨和总氯浓度的变化对锌溶解度的影响,为锌湿法冶金提供了热力学数据。

简介：Duetothedisturbancesofspatters,dustsandstrongarclight,itisdifficulttodetectthemoltenpooledgeandtheweldlinelocationinCO2weldingprocesses.Themedianfilteringandself-multiplicationwasemployedtopreprocesstheimageoftheCO2weldinginordertodetecteffectivelytheedgeofmoltenpoolandthelocationofweldline.TheB-splinewaveletalgorithmhasbeeninvestigated,theinfluenceofdifferentscalesandthresholdsontheresultsoftheedgedetectionhavebeencomparedandanalyzed.TheexperimentalresultsshowthatbetterperformancetoextracttheedgeofthemoltenpoolandthelocationofweldlinecanbeobtainedbyusingtheB-splinewavelettransform.Theproposededgedetectionapproachcanbefurtherappliedtothecontrolofmoltendepthandtheseamtracking.

简介：泡沫铝作为一种新型多功能材料具有很多优点,采用CO2对气体保护焊连接泡沫铝进行研究,分析了其焊接质量及拉伸强度。研究结果表明：对于闭孔和开孔两种泡沫铝来说,适宜的焊接速度能得到较好的表面焊接质量;焊接试验结果表明：5mm孔径大小的闭孔泡沫铝焊接速度在7mm/s比较适合,而焊接3mm和7mm孔径大小的开孔泡沫铝4mm/s时的表面焊接质量较好;拉伸结果表明：对于闭孔泡沫铝来说,采用CO2气体保护焊接方法强度较高,而开孔泡沫铝由于中空的孔导致焊接时焊缝处材料数量较少进而使得焊接强度并不高,因此需要进一步的深入研究。

简介：Pt(Ⅱ)andPd(Ⅱ)complexeswith2',3',4',5,7-pentahydroxy-flavoneweresynthesizedandcharacterizedbyelementalanalysis,molarconductance,IR,1HNMR,TG-DTA,UV-Visspectroscopictechniques,andfluorescenceanalysis.Thescavengingeffectonthesuperoxideradical(O-2)andtheinhibitoryeffectonlipidperoxideswerealsoinvestigated.Boththeligandandthecomplexesexhibitscavengingeffectonsuperoxideradicals,andtheeffectofthecomplexesisgreaterthanthatoftheligand.ThePt(Ⅱ)complexexhibitsthestrongestscavengingefficiency.BothPt(Ⅱ)andPd(Ⅱ)complexeshavetheinhibitoryeffectonlipidperoxides,andtheeffectofthecomplexesisgreaterthanthatoftheligand,butthePt(Ⅱ)complexhasahigheffectofpromotinglipidperoxides.

简介：齿轮组件经500h工作后,有1个齿发生了断裂。通过断口宏微观检查、能谱分析,对断裂齿轮的金相组织、化学成分、硬度、表面粗糙度和烧伤情况进行分析,结合对加工方式跟踪,分析结果表明：该齿断裂性质为疲劳断裂,主要与砂轮磨削加工中产生的镶嵌物有关,结合加工生产实际,建议减少磨削进给量,使用合适的冷却液,必要时加以放大镜以及体视显微镜进行检查,尽量避免或减少镶嵌物的产生。

简介：TheelectronicstructuresofspinelMgAl2O4andMgOtunnelbarriermaterialswereinvestigatedusingfirst-principlesdensityfunctionaltheorycalculations.OurresultsshowthatsimilarelectronicstructuresarefoundfortheMgAl2O4andMgOtunnelingbarriers.ThecalculateddirectenergygapsattheΓ-pointareabout5.10eVforMgAl2O4and4.81eVforMgO,respectively.BecauseofthesimilarfeatureinbandstructuresfromΓhigh-symmetrypointtoFpoint(△band),thecoherenttunnelingeffectmightbeexpectedtoappearinMgAl2O4-basedMTJslikeinMgO-basedMTJs.ThesmalldifferenceofthesurfacefreeenergiesofFe(2.9J.m-2)andMgAl2O4(2.27J·m-2)onthe{100}orientation,andthesmallerlatticemismatchbetweenMgAl2O4andferromagneticelectrodesthanthatbetweenMgOandferromagneticelectrodes,thespinelMgAl2O4cansubstituteMgOtofabricatethecoherenttunnelingandchemicallystablemagnetictunneljunctionstructures,whichwillbeappliedinthenextgenerationreadheadsorspintronicdevices.

简介：Theobjectiveofthisstudyistoinvestigatetheinfluenceofaddingtinyamountofmixedrareearth(La,Ce)andSrtoAl-20Cu-5Si-2Nifillermetal,byanalyzingthemicrostructure,wettabilityandmechanicalpropertiesofbrazedjoints.Theresultsshowthawiththeadditionofmixedrareearth(La,Ce)intoAl-20Cu-5Si-2Nialloy,theα-AlsolidsolutionaswellasCuAl_2(Ni)intermetalliccompoundphasesignificantlyreduced,whilemoreAl-SieutecticphaseandAl-Si-Cuternaryeutecticphasewereproduced.Andasmixedrareearth(La,Ce)addedin,thewettabilityofAl-20Cu-5Si-2Nifillermetaldecreased,whiletheshearstrengthofthebrazedjointsincreased.TheadditionofMinorSrmodificatedAl-20Cu-5Si-2Nifillermetal,furtherreducedtheCuAl_2(Ni)intermetalliccompoundphase,whichwaspartiallyreplacedAl-Si-Cuternaryeutecticphase.Asaresult,thetensilestrengthaswellasthewettabilityofthefillermetalwasimproved.

简介：LaserweldingwithfillerwireofAZ31magnesiumalloysisinvestigatedusingaCO2laserexperimentalsystem.Theeffectofthreedifferentfillerwiresonthejointpropertiesisresearched.Theresultsshowthattheweldappearancecanbeeffectivelyimprovedwhenusinglaserweldingwithfillerwire.ThemicrohardnessandtensilestrengthofjointsarealmostthesameasthoseofthebasemetalwhenERAZ31orERAZ61wireisadopted.However,whenthefillerwireofER5356aluminumalloyisused,themechanicalpropertiesofjointsbecomeworse.ForERAZ31andERAZ61fillerwires,themicrostructureofweldzoneshowssmalldendritegrains.Incomparison,forER5356fillerwire,theweldshowsastructureofsnowydendritesandmanyintermetalliccompoundsandeutecticphasesdistributeinthedendrites.Theseintermetallicconstituentswithlowmeltingpointincreasethetendencyofhotcrackandresultinfragilejointproperties.Therefore,ERAZ31andERAZ61wirearemoresuitablefillermaterialthanER5356forCO2laserweldingofAZ31magnesiumalloys.

简介：通过一个简单的水热方法成功地合成出由SnO2纳米片作次级结构的新型花状ZnSnO3-SnO2分级纳米结构。ZnSnO3多面体在生长分级SnO2纳米片的过程中主要起模版作用,制备出的SnO2纳米片的厚度约为25nm。还讨论了ZnSnO3-SnO2样品的形貌随反应时间变化的规律,并且进一步讨论了形成这种分级结构的形成机制。此外,由这种新型ZnSnO3-SnO2纳米结构作敏感材料的气体传感器对乙醇气体具有高灵敏和快响应的特点。ZnSnO3-SnO2纳米片在最佳工作温度270°C时,对50×10-6乙醇气体的灵敏度约为27.8,其响应和恢复时间分别在1s和1.8s内。

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