简介：《中小学数学》初中(教师)版2004年第5期刊载了张孝达老师一文《学生认为(-3)×(-4)=9该怎么办?》，对此，我谈谈自己的感想以及教学措施。

简介：重点词汇及短语精析1．pourv．倾倒：（雨）倾盆而下；涌流，倾泻

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简介：l、2、3、4——四只小羊齐步走左、右，左、右——齐步走

简介：摘要所谓领导，就是带领和引导。作为新时期的领导，面对性格各异、能力不同的下属，如何调动工作积极性、发挥其优势特长、增强其团队协作能力，成为当代领导人面临的重要课题。独具个性和人格魅力，是一个领导的必备条件，《西游记》里的唐僧作为一个成功的性格化领导，给了我们很好的启示和借鉴作用。

简介：1．distancen．距离：间距【用法精析】What’sthedistancebetweenNewYoukCityandBoston（=fromNewYoukCitytoBoston）？纽约市离波士顿有多远？DistanceisnoproblemontheInternet．在互联网上距离已不成问题。

简介：重点词汇及短语精析1．trustv．信赖，信任，相信

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简介：在空气环境下，用化学共沉淀法制备了磁性Fe3O4纳米粒子。探讨了磁性Fe3O4纳米粒子的最佳制备条件；对样品进行了XRD、IR、VSM等表征。样品表征表明，在最佳制备条件下所制备的Fe3O4磁性纳米粒子为反立方的尖晶石型，粒径约为20nm，饱和磁化强度在61．0e—mu／g以上，具有超顺磁性。

简介：磁铁矿(Fe3有不同尺寸和形状的O4)nanoparticles被热分解方法综合。二条途径，非注射一个壶和热注射的方法，被设计详细调查生长机制。nanoparticles的尺寸和形状被调整先锋集中和持续时间时间决定，这被发现，它能好在我们的合成系统基于LaMer模型由机制解释了。monodisperseFe3O4nanoparticles从5nm有一条吝啬的直径到16nm，和形状进化从对球形三角形、立方。磁性是尺寸依赖者，和Fe3在关于在房间温度和最大的浸透磁化的5nm展览superparamagnetic性质的小尺寸的O4nanoparticles来临到78emu/g，而Fe3O4nanoparticles当直径增加到大约16nm时，开发铁磁性的性质。

简介：Li1.3Al0.3Ti1.7(PO4)3pelletssinteredwithdifferentmolefractionsofLiBO2werepreparedbysol-gelmethod.Thestructuralidentification,surfacemorphology,ionicconductivity,andactivationenergyofthepelletswerestudiedbyX-raydiffraction,scanningelectronmicroscopy,andelectrochemicalimpedancespectroscopy.TheresultsshowthatalltheLi1.3Al0.3Ti1.7(PO4)3pelletssinteredwithdifferentmolefractionsofLiBO2havesimilarX-raydiffractionpatterns.ThesinteredpelletbecomesdenserandtheboundaryandcorneroftheparticlesbecomeillegiblewiththeincreaseofLiBO2.AmongtheLi1.3Al0.3Ti1.7(PO3)4pelletssinteredwithdifferentmolefractionsofLiBO2,theonesinteredwith1mol%LiBO2showsthehighestionicconductivityof3.95×10-4S.cm-1andthelowestactivationenergyof0.2469eV.

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简介：Inthepresentpaper,novelsidewallmaterialsforaluminumreductioncellwerepreparedinairusingmagnesiaandmagnetiteasstartingmaterials.ThesinteringbehaviorsofthespecimenswereinvestigatedbymeansofX-raydiffraction(XRD)andscanningelectronmicroscope(SEM).AndcorrosiontestsinaNa_3AlF_6-AlF_3-K_3AlF_6bathwereconductedtoevaluatetheelectrolytecorrosionresistance.TheresultsshowthattheFe_3O_4phaseistransformedintoFe_2O_3athightemperatures,whichinturnreactswiththeMgOaddedtoformMgFe_2O_4spinel.AndwithincreasingtheMgOcontentfrom0to30mass%,densificationofthespecimensdecreasesmainlyduetolargervolumeexpansionresultingfromformationofmoreMgFe_2O_4.ThecorrosiontestsshowthatcorrosionlayersareproducedinalltheMgOaddedspecimens.However,forspecimenscontainingMgFe_2O_4phaseonly,Mg(Al,Fe)_2O_4compositespinellayersarealsogenerated,whichremarkablyimprovethecorrosionresistanceofthespecimens.

简介：研究了一种制备Mn3O4的方法，以廉价的硫酸锰为原料，通过控制反应条件制得了高纯度的纳米级Mn3O4。实验结果表明，反应的最佳条件为：加适量乙醇作为分散剂；控制氨水滴加速度使反应时间在2h以上；前驱物在200℃煅烧2h。采用X射线衍射（XRD）、透射电子显微镜（TEM）等手段对产物进行了表征，产物纯度为100％，粒径约为20nm。

简介：LargeGdCa4O(BO3)3crystalhasbeengrownbytheCzochralskimethod.ThequalityofGdCa4(BO3)3crystalwasassessedbywhite-beamsynchrotronradiationtopography.Ithasbeenfoundthatthereisasub-grainboundaryintheGdCa4O(BO3)3crystal.TheboundarydividesthelargeGdCa4O(BO3)3crystalintotwoindividuals.Duetothemisorientationbetweenthetwoindividuals,theimageshiftscanbeobservedinthesynchrotrontopopraphs.BasedonthemisorientationdeterminedbyhighresolutionX-raydiffractometer,theimageshiftswerecalculatedforseveralreflections.ThecalculationsareinagreementwiththemeasurementsfromthetopogrphsveryWell.Inaddition,theformationmechanismofsub-grainboundaryisdiscussed.2001ElsevierscienceB.V.Allrightsreserved.

简介：ThephotocatalystsK4Nb6017andK4Nb6017dopedwithFe^3+andCr^3+werepreparedbysolidstatereactionandwerecharacterizedbypowderx-raydiffraction,UV-visdiffusivereflectanceandscanningelectronmicroscopy.ThephotocatalyticactivityofK4Nb6O17andK4Nb6O17dopedwithFe^3+,Cr^3+wereinvestigatedwithmethanolaselectrondonorandPtaspromotercatalystunder+400nmUVirradiation.Thedifferenceofphotocatalyticactivitybetweenthemwasalsodiscussed.TheindividualrateofhydrogenevolutionfortheK4Nb6O17,Fe-K4Nb6O17andCr-K4Nb6O17asphotocatalystsare5.35,5.00,6.25mmol·L^-1.h^-1respectively.

简介：ThegrowthdetectsinNd:YCa4O(BO3)3(Nd:YCOB)crystalswereinvestigatedbytransmissionsynchrotrontopography.ItwasfoundthatgrowthstriationsweretheprimarydefectsinNd:YCOBcrystals.Grown-indislocations.mosaicblocksandinclusionswerealsoobseredinthecrystals.Theeffectoftemperaturefieldontheformationofgrowthdefectsinthecrystalswasdiscussed.

简介：1．状语从句用适当的连接词填空。1.Ihadjustwalkedoutofthebathroomandwasbusilydryingmyselfwithatowel_Iheardthesteps.