一水甲酸锂晶体二阶非线性光学系数的理论计算

采用有限场方法和含时耦合微扰方法,在6-31+G*基组水平上并考虑了电子相关效应和色散效应的影响,计算了一水甲酸锂晶体的宏观二阶非线性光学极化率和二阶非线性光学系数。其中非线性光学系数d31和d32与Roberts报道的相符,而另一个系数d33则比文献值大。计算结果还表明,在非共振情况下,电子相关效应对非线性光学极化率的影响远远超过了色散效应,同时表明Roberts报道的非线性光学系数比Singh等人报道的更为合理。     

过渡金属类立方烷原子簇化合物电子结构和二阶非线性光学性质的密度泛函理论研究

采用基于第一原理的含时密度泛函理论(TDDFT)对一系列具有类立方烷簇芯结构的过渡金属簇合物二阶非线性光学性质进行了研究。结果证明, 由于簇芯结构的对称性的影响, 这一类簇分子的二阶非线性光学系数的数值要小于三核欠完整类立方烷体系。通过对电子结构的分析, 发现二阶非线性光学性质主要是由簇芯内电荷的迁移造成的。轨道分析显示, -S原子对于电荷的迁移起主要的传递作用。定域化轨道分析证明簇分子中存在的多中心键有利于簇芯内电荷的迁移。分子模拟的研究表明:虽然类立方烷结构簇分子的值比较小, 但是通过合理的配体设计, 获得具有较大值非线性光学晶体是可能的。     

LAP晶体二阶NLO响应电子起源理论研究

L-精氨酸磷酸盐(L-Arginine Phosphate Monohydrate, LAP)晶体，是一种有应用潜力的无机－有机杂化NLO晶体材料[1, 2]。Eimerl等人认为LAP晶体二阶NLO响应主要源于L-精氨酸分子(Arg )，磷酸根(H2PO4－)对LAP晶体宏观NLO响应没有重要贡献[2]；而许东等人认为，LAP晶体的NLO响应是由L-精氨酸分子和磷酸根共同贡献的结果[1]。本通讯通过第一原理从头算计算，揭示了LAP晶体二阶NLO响应的电子起源。 表1. 激发态性质 Table 1. The Excited States at CIS/STO-3G Level (Dmge in Debyes; l in nm; (rx)ge in au) States…     

储氧材料制备过程中的结构及织构变化

Ce_0.65Zr_0.35O₂ solid solution was prepared by co-precipitation method and characterized by X-ray diffraction (XRD), Raman spectra, BET, oxygen storage capacity (OSC) and temperature-programmed reduction measurements (H₂-TPR) after calcination at 100 ℃, 300 ℃, 600 ℃, and 1 000 ℃. The results showed that the precipitation was a crystalline of fluorite structure, and in the process of the precipitation transformation into Ce_0.65Zr_0.35O₂ solid solution, the fluorite structure of the precipitation kept unchanged. The samples had different BET surface areas and OSC at different temperatures, but they held the performance of stable structure. After 1 000 ℃, there didn′t appear the other crystalline phase. So the samples prepared by co-precipitation method had excellent texture and higher thermal stability.     

新型一维梯状双链配位聚合物{[Cu(malate)(2,2'-bipy)]•3H2O}∞的合成、晶体结构与表征

合成了铜(II)与羟基丁二酸和2,2'-联吡啶形成的配位聚合物{[Cu(malate)(2,2'-bipy)]•3H₂O}_∞ (其中malate＝羟基丁二酸根, 2,2'-bipy＝2,2'-联吡啶), 通过X射线衍射测定了单晶结构, 并进行了元素分析、红外光谱、紫外光谱、热分析等研究. 配合物属单斜晶系, 空间群P2(1)/c; 晶胞参数: a＝0.70132(10) nm, b＝1.9730(3) nm, c＝1.18998(16) nm, β＝94.551(3)°; Z＝2; 最终偏离因子R＝0.0483. 配合物中每个铜(II)原子与来自2,2'-联吡啶的两个氮原子和两个羟基丁二酸根的三个氧原子配位, 形成畸变的三角双锥结构单元. 每个羟基丁二酸根以R构型方式桥联两个三角双锥结构单元, 沿a轴方向无限延伸形成一维链. 两条平行链以面对面的方式重叠, 彼此吡啶环之间存在强的(-(相互作用, 加之C_吡啶环—H…O_羧基弱相互作用形成新颖的梯状双链结构, 比邻的梯状双链又通过分子间O_羟基-H…O_羧基氢键沿a轴方向共同构筑了具有隧道的三维结构.     

Modified (2+1)-dimensional displacement shallow water wave system and its approximate similarity solutions

Recently, a new (2+1)-dimensional shallow water wave system, the (2+1)-dimensional displacement shallow water wave system (2DDSWWS), was constructed by applying the variational principle of the analytic mechanics in the Lagrange coordinates. The disadvantage is that fluid viscidity is not considered in the 2DDSWWS, which is the same as the famous Kadomtsev—Petviashvili equation and Korteweg—de Vries equation. Applying dimensional analysis, we modify the 2DDSWWS and add the term related to the fluid viscidity to the 2DDSWWS. The approximate similarity solutions of the modified 2DDSWWS (M2DDSWWS) is studied and four similarity solutions are obtained. For the perfect fluids, the coefficient of kinematic viscosity is zero, then the M2DDSWWS will degenerate to the 2DDSWWS.     

广义耦合KdV孤子方程的达布变换及其奇孤子解

借助谱问题的规范变换, 给出广义耦合KdV孤子方程的达布变换,利用达布变换来产生广义耦合KdV孤子方程的奇孤子解,并且用行列式的形式来表达广义耦合KdV孤子方程的奇孤子解．作为应用,广义耦合KdV孤子方程奇孤子解的前两个例子被给出．     

1-取代苯氧乙酰基-4-芳酰基氨基硫脲的合成及生物活性

苯氧乙酰肼;1-取代苯氧乙酰基-4-芳酰基氨基硫脲的合成及生物活性     

Drift vortices in inhomogeneous collisional dusty magnetoplasma

For the sake of investigating the drift coherent vortex structure in an inhomogeneous dense dusty magnetoplasma,using the quantum hydrodynamic model a nonlinear controlling equation is deduced when the collision effect is considered.New vortex solutions of the electrostatic potential are obtained by a special transformation method, and three evolutive cases of monopolar vortex chains with spatial and temporal distribution are analyzed by representative parameters. It is found that the collision frequency, particle density, drift velocity, dust charge number, electron Fermi wavelength, quantum correction,and quantum parameter are all influencing factors of the vortex evolution. Compared to the uniform dusty system, the vortex solutions of the inhomogeneous system present richer spatial evolution and physical meaning. These results may explain corresponding vortex phenomena and support beneficial references for the dense dusty plasma atmosphere.