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141.
Xiao-Bin Xu Fei-Fei Lan Shi-Yao Yang Ming Li Rong-Bin Huang Lan-Sun Zheng 《Journal of chemical crystallography》2010,40(6):551-556
Abstract
Two 3D supramolecular architectures, [Cu(tmbdc)(NH3)2] n , 1, (tmbdc = 2,3,5,6-tetramethylbenzenedicarboxylate), and {[Cu3(btc)2(NH3)6(H2O)]·2H2O} n , 2, (btc = 1,3,5-benzenetricarboxylate) have been assembled with 1D or 2D coordination polymers as supramolecular synthons. The geometry matching of the moieties is the key factor for the formation of the two supramolecular architectures by the cooperation of coordination bonds, hydrogen bonds and π···π interactions. Crystal data for 1: Formula CuC12H18N2O4, monoclinic, space group P21/c, a = 9.0134(5), b = 10.8785(5), c = 6.4702(3) ?, β = 91.679(1)°, V = 634.15(5) ?3, Z = 2, R 1 = 0.0251 and wR 2 = 0.0722. Crystal data for 2: Formula Cu3C18H30N6O15, monoclinic, space group C2/c, a = 13.9213(5), b = 17.1210(6), c = 12.5271(5) ?, β = 114.779(1)°, V = 2710.89(17) ?3, Z = 4, R 1 = 0.0245 and wR 2 = 0.0665. The positions and isotropic displacement parameters of all the hydrogen atoms are refined. 相似文献142.
利用Dirac-Slater相对论平均自洽场理论,研究了不同原子体系光电离截面在不同核模型下的差异.考虑原子核大小时,核的尺寸效应使电子所感受到的有效核电荷减小,并进而影响到电子的概率分布及光电离截面等;对没有考虑原子核大小的点模型,由于不存在核的尺寸效应,出射光电子的波函数有较大相移,从而有可能出现Cooper极小.当入射光子的能量远大于相关电子的电离能时,不同核模型下电子束缚能及平均半径等的差异将相对减小,从而使光电离截面随入射光子能量的变化趋于一致. 相似文献
143.
BESⅢ主漂移室重建径迹的外推算法采用面向对象的设计方法, 利用GEANT4部分代码开发实现, 它提供主漂移室带电径迹外推到外部其他子探测器上的预期径迹信息. 该算法的外推过程考虑了带电径迹在磁场中的偏转以及与探测器物质相互作用造成的电离能损, 并为径迹参数计算考虑了库仑多次散射效应影响在内的参数误差矩阵. 经检查, 主漂移室径迹的外推结果和完全模拟结果一致, 并且径迹外推的结果能够成功用于各个子探测器测量径迹间的匹配, 这些工作为分析实验数据作了必要的准备, 能够满足BESⅢ实验的使用要求. 相似文献
144.
Xiao-Bin Dai 《Physica A》2007,383(2):624-630
Using molecular dynamics (MD) simulation and evolutionary game theory, we incorporate the spacial structure of individuals into the study of the behaviors of cooperation, by adopting the prisoner's dilemma and snowdrift game as metaphors of cooperation between unrelated individuals. The results show that the introduction of spacial structure enhances cooperation using the strategy of prisoner's dilemma while does not make much changes to the cooperation if the strategy of snowdrift game is used. It is also found that our model is a meta-phase between regular ring graph model and complex network model. And the “activity of players” T* we introduced makes our simulation much more closer to real world problems. 相似文献
145.
Guo-Yuan Lu Wei Song Feng Tang Xiao-Bin Wan Fang Liu Chuan-Min Jin 《Journal of chemical crystallography》2000,30(7):483-487
Crystal structure of a novel bis(guanidiniums) compound 1 by sulfate anion and water, C11H20N6OSO4H2O, was measured by X-ray crystallographic analysis with an imaging plate method. It possesses space group P21/c, with a = 7.6433(15), b = 19.447(4), c = 12.115(2) Å, = 107.81(3)°, and calc = 1.420 mg/m3 for Z = 4. Crystal data indicate that the architecture network is formed through hydrogen bonds, electrostatic interactions, and arene–arene stacking interaction among the bis(guanidiniums) compound, the sulfate anion and water molecule. 相似文献
146.
147.
148.
镧石型碳酸钕的形成及晶种对结晶的促进作用 总被引:3,自引:1,他引:3
The characteristics of pH value variation during aging process of amorphous neodymium carbonate formed by three different feeding manners have been investigated. The promotion action of seeding on the crystallization of neodymium carbonate is discussed. X-ray diffraction pattern and the elemental analysis results show that neodymium carbonate can transfer from amorphous to crystalline normal neodymium carbonate Nd2(CO3)3·8H2O with lanthanide structure at room temperature. Its crystallization activity zone lies in lower feeding ratio area expressed by nNH4HCO3/nNdCl3 between 2~3. The existing of seeds can shorten crystalline time, from more than 15 h without seed to 2 h with seeds under normal feeding manner. And the spontaneity nucleation time can be shortened further when feeding with multi-steps normal manner. However, whether multi-steps normal or synchronously and continuously feeding manner, the precipitate formed can transfer to crystalline neodymium carbonate directly under seeding. At the same time, it is observed that the variation of pH value reduces with the decrease of feeding amount and the shortening of aging period, indicating that with synchronously and continuously feeding manner can not only realize fast crystallization, but also control pH value within a narrow range, which is beneficial for the producing of neodymium carbonate crystal with narrow-distributed particle size and monitoring of its crystallization process. 相似文献
149.
γ-MnOOH multipods were synthesized by a low temperature hydrothermal method. The synthetic procedure is based on the use of PEG200 to reduce KMnO4 upon controlling the volume of PEG200. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) were used to characterize the products. All pods of them are single crystals, the diameter of each pod is about 40~120 nm and the length is about 800~2 400 nm. A possible formation mechanism was proposed that the intermediate products with a lamellar morphology curled into γ-MnOOH nanorods during the reaction process at first, and then γ-MnOOH multipods formed for the multi-nuclei growth on the tips of the γ-MnOOH nanorods when they were good crystallization. 相似文献
150.
Design of temperature sensitive imprinted polymer hydrogels based on multiple-point hydrogen bonding
Weakly cross-linked temperature sensitive imprinted polymer hydrogels that recognize L-pyroglutamic acid (Pga) molecules via multiple-point hydrogen bonding were designed and synthesized. The amount of adsorption for Pga in imprinted hydrogels is 3-4 times higher than that in non-imprinted hydrogels. The selectivity test of imprinted polymer gels was carried out by using a series of structurally related compounds Pga, pyrrolidine, 2-pyrrolidone, L-proline as substrates. The results show that imprinted polymer gels exhibit high selectivity for Pga as compared to all the other tested substrates. The imprinted polymer hydrogels show good temperature sensitivity, special selectivity and reusability, suggesting that the polymer hydrogels would have an enormous potential for application in controlled drug release and separation field. 相似文献