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在水热条件下合成了一例新型的多金属氧酸盐二聚物,[Ni(enMe)2]4{[Ni(enMe)2][Ni(enMe)2(H2O)]2[Mo8ⅥV6ⅣO38(VⅤO4)]2}.8H2O(1)(enMe=1,2-丙二胺),利用元素分析、红外光谱分析、粉末X射线衍射、热重分析和单晶X射线衍射表征了其结构。结果表明,化合物(1)属于单斜晶系,P2(1)/n空间群.晶胞参数为a=1.9685(4)nm,b=1.3549(3)nm,c=2.7039(5)nm,α=90°,β=93.94(3)°,γ=90°,V=7.195(2)nm3,Z=4,Dc=2.390g/cm3,Mr=2588.4,μ=3.195mm-1,F(000)=5012,最终R1=0.0743,wR2=0.1861.与此同时,(1)是第一个具有二帽-Keggin型钼钒氧簇的二聚体,它由过渡金属部分[Ni(enMe)2(H2O)]22+连接形成{[Ni(enMe)2][Ni(enMe)2(H2O)]2[Mo8ⅥV6ⅣO38(VⅤO4)]2}8-二聚阴离子. 相似文献
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11血roductlonAssume that BC(H)={p:(一 co,0]一R Is continuous and 11 yi 11二sup卜(。)l三 H}and that F:[0;+比)X BC(H)一 Ris a given cofltiflllollSs<0function;such that F(·,0)三 0.A>0 Is a constant.Consider one-dimensionaldel叫dl俭rentlal equationX川+入X(z)=*I,X;).(1〕In addition to the conditions above F also satisfies same conditions such thatthe SOllltiofl Of Eq.(1)x(t)=x(t; to;i)llllqllely eXIStS Oil壬to;十①)for。11[to;i) E R+ X BC(H(See [*]).FOr every yi … 相似文献
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CONVERGENCEANDSTABILITYOFSOLUTIONSOFCERTAININFINITEDELAYDIFFERENTIALEQUATIONSChenWuhua(GuangXiNationalInstitute,Abstract:ByCo... 相似文献
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A new method is reported for the preparation of dialkylphosphinic acids and their derivatives based on the reaction of dialkylphosphinous acid with a nucleophile and base in the presence of carbon tetraehloride. The influence of the reaction conditions and the structure of nueleophiles on the yield of the oxidative phosphinylation is examined. It is proposed that the reaction operates by an ionic process rather than a radical mechanism. 相似文献
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辛基膦酸单辛酯的合成及其萃取镧系元素的结构-性能研究 总被引:1,自引:1,他引:0
合成了九个不同辛基结构的辛基膦酸单辛酯,测定了它们的正十二烷溶液在恒定离子强度和不同酸度的硝酸介质中萃取镧、铕和铅的分配比,并以外推法得到了归一化的分配比数值,从而进行了萃取剂结构与性能关系的研究。考察了辛基膦酸单辛酯的烷基支链化程度时萃取镧系元素的能力和分离性能的影响:随着邻近配位基团的烷基支链化程度的增加,其萃取能力下降;但一定的支链对萃取剂分子是必需的,如2-乙基已基膦酸单2-乙基己基酯和正辛基膦酸单1-甲基庚基酯皆具有最佳的分离性能。从空间效应解释了所得的结果。 相似文献
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Polyoxometalates(POMs) with Cd-coordination complexes acting as supporting units are rarely reported. The linkage of the supporting units with inorganic building block(polyanion) is generally established on terminal O-atoms, but scarcely via bridging O-atoms. By introducing liquid small organic molecule(pyridine, C5NH5) as assistant "structure-directing agent", we obtained a novel organic-inorganic hybrid polytungstate,(Hpy)4[Cd(phen)2(P2W18O62)]·nH2O(1, n ≈ 3, py = pyridine, phen = 1,10-phenanthroline), under hydrothermal conditions. The single-crystal X-ray diffraction analysis shows that 1 is the first compound containing an asymmetric heteropolyanion, [Cd(phen)2(P2W18O62)]4–, a Wells-Dawson-type polyanion monosupported by Cd-coordination complex via di-bridging O-atoms. 相似文献
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针对具有范数有界不确定性的线性离散时间系统,研究了鲁棒状态反馈脉冲镇定问题.首先,引入与脉冲时间序列相关的时变Lyapunov函数,运用凸组合技术,给出一种能够保证闭环系统鲁棒指数稳定性的状态反馈脉冲控制律存在的充分条件;其次,证明了该条件可转化为一组线性矩阵不等式可解性问题.通过求解这组线性矩阵不等式,可以获得鲁棒状态反馈脉冲控制律增益矩阵;最后,通过数值例子说明所得结果的有效性. 相似文献
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UNIFORMSTABILITYFORADIFFERENTIALEQUATIONChenWuhua(陈武华)(GuangxiNationalInstitute,广西民族学院,邮编:530006)Abstract:Inthispaper,wegives... 相似文献