183 resultados para 278


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非线性光学新材料K2Ln(NO3)5·2H2O(Ln=La,Ce,Pr,Nd,Sm)的晶体生长、结构和表征董文庭张洪杰苏锵(中国科学院长春应用化学研究所稀土化学与物理开放实验室,长春130022)Growth,StructureandCharact...

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一种新的Eu ̄(3+)配合物有机薄膜电致发光王子君,李斌,范翊,张洪杰,蒋大鹏,李亚君,张立功,关中素,吕安德(中国科学院长春物理研究所,长春130021)(中国科学院长春应用化学研究所稀土化学和物理开放实验室,长春130022)自从C.W.Tang…

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研究了4种共混比的LnBR/SBR共混生胶、混炼胶及硫化胶的性能,并与NiBR/SBR共混胶进行了对比。结果表明,共混生胶的ML均低于LnBR及SBR;当LnBR/SBR共混比大于20/80时,呈现2个Tg;而大于80/20则出现应变诱导结晶现象。LnBR/SBR共混混炼胶的ML、剪切应力、出口膨胀及硫化速度均低于NiBR/SBR共混胶,挤出物外观优于后者;共混硫化胶的拉伸强度、热空气老化、拉伸疲劳、湿滑、耐磨等性能均明显优于后者,生热和透气率高于后者。

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合成了通式为K5-nHn[α-,βi-SiW11M(H2O)O39]·xH2O(M=Al,Ga,βi=β1,β2,β3)的八种异构体。通过元素分析、红外光谱和紫外光谱、极谱和循环伏安、27Al和183W核磁共振、X光电子能谱等方法进行了表征。所合成的各异构体在催化以H2O2为氧化剂的顺丁烯二酸环氧化反应中,β3异构体具有最高的催化活性

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The correlations of the calcination temperature, structure and catalytic activity for the oxidative coupling of methane on the LiLa0.5Ti0.5O2+lambda catalysts whose main phase and major active phase is Perovskite-type ternary complex oxide LaTi1-yLiyO3-lambda have been studied. The surface and bulk structures of the catalysts were characterized by means of XRD, XPS, IR, BET and so on, The results cleary indicated that the effect of calcination temperature on the activity for the oxidative coupling of methane is twofold. On one hand, it is favorable for Li+ substitution for Ti3+ to enter into the lattice of LaTiO3 and produce more oxygen vacancies in which active oxygens are formed; however, excessively high calcination temperature make the amount of Li+ substitution for Ti3+ lower, due to a little change of structure or phases for the catalyst. On the other hand, the conversion of CH4 drops because of the decrease of surface area, when the calcination temperature is raised.

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探讨了焙烧温度对钙钛矿型复合氧化物LaTi1-yLiyO3-λ(0≤y<1)为主要物相的LiLa0.5Ti0.5O2+λ催化剂的结构及甲烷氧化偶联反应活性的影响机制,用XRD、IR、XPS和BET等方法对催化剂进行表征。结果表明,焙烧温度对催化剂的OCM反应活性的影响是双重的。提高焙烧温度有利于Li+进入LaTiO3晶格(或间隙)产生更多数量的氧空位,进而产生更多的活性氧种,有利于OCM反应的进行,但过高的焙烧温度又使催化剂的结构(或物相)发生变化,因而使Li+的取代量、比表面积和甲烷转化率均下降。

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比较了具有单功能基团的共轭有机小分子噻吩和四氢噻吩对细胞色素c直接电化学反应的促进作用。发现四氢噻吩不能加速细胞色素c的直接电化学反应。而噻吩是一种很好的促进剂。表明噻吩分子中的共轭π键在加速细胞色素c的电子传递过程中起着重要作用。

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A glassy carbon electrode (GCE) modified with palladium provides excellent electrocatalytic oxidation of hydrogen peroxide. When the electrolyte contains palladium chloride and glucose oxidase, the GCE can be modified by electrochemical codeposition at a given potential. The resulting modified surface was coated with a thin film of Nation to form a glucose sensor. Such a glucose sensor was successfully used in the flow-injection analysis of glucose with high stability and anti-poisoning ability. It gave a detection limit of 1 X 10(-7) M injected glucose, with a linear concentration range of 0.001-8 mM. There is no obvious interference from substances such as ascorbate and saccharides.

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The C-H stretching, C-H bending, C-C stretching and the low-frequency vibration regions have been investigated by Raman spectroscopy for [n-CnH2n+1NH3]2 ZnCl4 with n=7 approximately 12, 16. It is found that their frequency and relative intensities are related to the length of carbon chain in the molecules and present the odd-even effect to carbon atom numbers in chain. Some changes in spectra are interpreted in terms of the different molecular packing and interaction of chain.

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合成了四个甲基乙撑桥联二环戊二烯基环戊二烯基稀土四氢呋喃配合物,采用元素分析、红外光谱、核磁共板、热失重和质谱等方法对所得到配合物进行表征,并用X光衍射法测得Me_4C_2(C_5H_4)_2SmC_5H_3(THF)的晶体结构。该晶体属正交晶系C_(e2a)空间群,a=1.1696(6),b=1.2539(5),c=2.9432(15)nm;V=4.316(4)nm~3,z=8,D_c=1.54g·cm~(-3)。三个环戊二烯基Sm-C(η~5)距离分别为0.272(3),0.276(3),0.278(3)nm和Sm-O键长为0.253(1)nm。

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测定了[n-C_nH_(2n+1)NH_3]ZnCl_4(n=7~12,16)配合物在碳氢伸缩、碳氢弯曲、碳碳伸缩和低频区的Raman光谱.发现它们的频率和相对强度与分子中烷基链的链长有关,并且表现出碳原子数的奇偶效应.从不同的分子堆积结构和分子间相互作用的角度讨论了光谱变化.

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本文给出了原子和离子能量表达式中的库仑积分与交换积分系数f~k与g~k的计算方法,同时给出了计算中所涉及的Racah系数、U~(k)、V~(lk)和C~(k)矩阵等光谱参量的计算方法,我们用FORTRAN语言编写了关于f~k与g~k的计算机程序,只要输入与光谱项有关的量子数,即可迅速得到相应的f~k与g~k值,避免了烦琐的人工推算。

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Radial distribution function of CaCl2-KCl (1:2 mol) melt was measured by X-ray scattering of high temperature liquid. The nearest neighbour distances of Ca2+-Cl-, K+-Cl- and Cl--Cl- ionic pairs are 0.278, 0.306 and 0.380 nm, respectively, Discussion on the relation between structure and physicochemical properties in the melt was simply done in this paper.

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用高温液态X射线衍射方法,测定了摩尔比为1∶2的CaCl_2-KCl熔体的径向分布函数。结果表明,熔体中Ca~(2+)-Cl~-、K~+-Cl~-和Cl~--Cl~-离子对间的最近邻距离分别为0.278,0.306和0.380nm.由于Ca~(2+)与Cl-间的强Coulomb作用,在熔融的摩尔比为1∶2的CaCl_2-KGl体系中,Cl~--Cl~-间的最近邻距离明显小于纯KCl熔体中Cl~--Cl~-间的最近邻距离。