简介:Ceriasphereswithdifferentsizesandsulfurizedproductswithcorrespondingmorphologywerepreparedbyhydrothermalandgas-solidreactionmethodat600–800°CunderCS2atmosphereforashorttime,respectively.Dimensionaleffectinpreparationofγ-Ce2S3wasfirstlyinvestigatedbymeansoftechniquessuchasscanningelectronmicroscopy(SEM),X-raydiffraction(XRD),thermalgravimetricanalysis(TGA)andspectrophotometer.Theresultsshowedthatwhenceriananoparticleswithsmallsizewereusedasprecursors,theγ-Ce2S3couldbepreparedatthelowertemperatureandthebadlysinteredproductswereobtained;whenceriananoparticleswithlargesizewereemployedasprecursors,pureγ-Ce2S3wasdifficultlyobtainedevenifthetemperaturewasupto800°Candtheproductstendedtokeeptheiroriginalsize.Theheat-resistancepropertyoftheγ-Ce2S3withlargesizewasbetterthanthesmallerone,andthepureγ-Ce2S3preparedfromprecursorwithsmallsizehadagoodpigmentaryperformance.
简介:利用高速摄像机对4名优秀男子手枪速射运动员4s组射击进行现场动作拍摄,同时采用秒表记录各动作时相时间,通过对动作录像和秒表采集时间的分析,来揭示4s射击的时间节奏特点.将4s组射击的动作阶段划分为五个时相:举枪至第1靶击发、第1靶至第2靶、第2靶至第3靶、第3靶至第4靶、第4靶至第5靶.研究发现:4s组每发子弹击发所用帧数为5~6帧(频率为63帧/s),发与发之间间隔帧数间隔帧数在26~38帧,大多数在28~34帧之间;举枪到第1发枪响,时间都在1.4~1.7s之间,发与发之间的时间间隔在0.4~0.6s范围内.对于男子手枪速射项目的节奏研究,高速摄像是一种精确、可靠的研究手段.
简介:采用密度泛函理论的B3LYP方法、从头算的MP2方法和自洽反应场极化连续模型(PCM),在6-311++G(2d,2p)基组水平上研究了N,N’-二甲基-S-异苯并呋喃在气相和溶液中发生S→N烷基重排反应的机理、溶剂效应和取代基效应.结果表明:该反应通过四元环机理和双位迁移机理生成产物,在气相和溶剂水中,双位迁移途径的能垒均比四元环途径低,反应主要通过双位迁移途径生成产物.在气相,苯环上发生-Cl,-NO2和-OCH3取代时,双位迁移途径的能垒在MP2/6-311++G(2d,2p)水平上比没有取代时分别低4.18,7.61,4.96kJ/mol,反应的取代基效应不明显.而在溶剂水中,苯环上发生-Cl,-NO2和-OCH3取代时,双位迁移途径的能垒在PCM-MP2/6-311++G(2d,2p)水平上比气相时分别低37.73,39.96和37.17kJ/mol,反应的溶剂化效应非常明显.理论研究结果与实验观察结果一致.
简介:TheemergenceofB2Belectronicmarketshasgreatlychangedtherelativebargainingpowerofbuyersandsellers.Westudytheequilibriummarketstructureinabuyer’smarket.Wefindthatbuyer-controlledB2BmarketsandneutralB2Bmarketshavedifferentequilibriumstructures,andtheemergenceofB2Bmarketswillincreasesocialwelfare,butitseffectonbuyersandsellerswillbedifferent:B2Bmarketsincreasetheconsumersurplusoftheendmarket,buttheireffectsonbuyerandsellerprofitsaremoderatedbytherelativebargainingpowerofbuyersandsellers.TheprofitsofthesidewithmuchweakerbargainingpowerwilldecreaseduetotheintroductionofB2Bmarkets.
简介:FromNovember30toDecember6,2014,China-U.S.YoungLeaders'Dialogue2014washeldinChengduandBeijing.Thedialogue,whichwassponsoredbyCIISandassistedbyChengduMunicipalForeignAffairsOffice,exploredaroundthetopicof'NewModelofMajor-CountryRelationship&China-U.S.CooperationonGlobalGovernance'.Dr.RuanZongze,VicePresidentofCIIS,chairedtheopeningceremonyandmadeopeningremarks.
简介:<正>HonoraryPresidents:WangGangFormerMemberofthePoliticalBureauoftheCentralCommitteeoftheCommunistPartyofChina(CPC)FormerVice-ChairmanoftheNationalCommitteeoftheChinesePeople’sPoliticalConsultativeConference(CPPCC)ZhouTienongFormerVice-ChairmanoftheStandingCommitteeoftheNationalPeople’sCongress(NPC)
简介:<正>AttheinvitationoftheChineseAssociationforInternationalUnderstanding(CAFIU),atenmemberdelegationof5NGOsfromPoland,Hungary,CzechandSerbia,headedbyMr.BartoszDominiakfrom"AmicusEuropae"FoundationofPoland,visitedChinafromApril14to23.Borninlate1970sand1980s,mostdelegatesarewell-educatedandveryperceptive.
简介:在吝啬地的三地点的BoseHubbard模型以内,偶极的bosonic气体与的通道动力学一周期性地,散布的s波浪的调整被调查。系统经历通道(CDT)的协调破坏转移在下邻居偶极子偶极子相互作用,所在地的相互作用和散布的调制s波浪之中源于相关效果的复杂、富有的协调通道(CT)。特别地,为产生CT(CDT)散布的调制s波浪的区域是最宽(最狭窄)什么时候所在地的相互作用和下邻居偶极子偶极子相互作用一些相关与通道精力和系统的相互作用精力有关仔细珍视,它是。为出现CDT的相关的值能理论上从通道精力和系统的相互作用精力被获得。