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1.
The studies on model systems XAuPH3(X-H,F,Cl,Br,I,CN,CH3)have been carried out by using ab intiol HF and DFT B3LYP methods at pseudopotential and double-zeta LANL2DZ level.The results are compared with those of MP2,The properties of the models.i.e.the atomic net charge populations.the frontier molecular orbitals and nonlinear optical(NLO)properties have been investigated under an applied electric field on the basis of optimized structures.The computational results show that for these models characterized as electron acceptor-metal-electron donor(A-M-D)system,the NLO properties are due to intramolecular charge-transfer interaction between the acceptor and the donor.The more charges transfer gives,the better NLO properties.In the selected model systems,IAuPH3 has the biggest βvec and γof 1184.1942 a.u.and 17341.9214 a.u.,whereas IC6H4PH3^ ,A TYPICAL a-π-D organic conjugated system,has βvec and γof 710.7697 and 11664.1405 a.u.respectively.In comparison.IAuPH3 has significant NLO properties.  相似文献   

2.
Density functional theory (DFT) B3LYP at 6-31G* level is employed to optimize the structures of the molecules bridged through n-vertex bis-substituted carborane (n=5, 6, 7) and combined with finite field (FF) formalism to calculate the second-order NLO properties. The results indicate that the structures of n-vertex bis-substituted carborane (n=5, 6, 7) are changed due to bridged donor and acceptor moieties. The distances between two C atoms are becoming longer. And the stability and dipole moment are in- fluenced by changing substituted positions of C atoms. The isomers with the substituents connecting with C atoms of lower coordination number have better stability and larger values of polarizability. One-dimensional structure of the molecules bridged through n-vertex bis-substituted carborane (n=5, 6, 7) is in favor of intramolecular charge-transfer. Meanwhile, the isomer with a larger change of dipole moment has larger value of second-order NLO properties during the charge-transfer process.  相似文献   

3.
《科学通报(英文版)》1996,41(16):1392-1392
In recent years, organic NLO materials have always attracted people's attention, especially the conjugated-π organic compounds with substitutes of electronic donor and acceptor, for example, (3-methyl-4-nitroaniline) (MNA), N-(4-nitrophenyl-(s)-prolinol (NPP), ((2, 4-dinitrophenyl)-amino-2-propanoate) (MAP), etc. Being made of delocalized aromatic  相似文献   

4.
含不同二硫醇盐的Pt(Ⅱ)吡啶三嗪配合物的二阶NLO性质   总被引:1,自引:0,他引:1  
采用量子化学DFT B3LYP/LanL2DZ+6\|31G*方法, 研究不同二硫醇盐的Pt(Ⅱ)吡啶-三嗪配合物的二阶非线性光学(NLO)性质. 结果表明: 配合物中配位原子间的距离与S=C共轭链长度密切相关; 在4种配合物中, 吡啶和三嗪部分表现出给电子特性, 二硫醇盐部分具有吸电子作用; 金属Pt(Ⅱ)可作为给电子的共轭桥, 4种配合物的偶极矩μ和极化率α成正比. NLO效应研究表明, 4种配合物均具有较大的βtot值, 可以作为潜在的NLO材料.  相似文献   

5.
以[(η5-C5Me5)2Mo2(μ-S)2S2 和Cu(MeCN)4(ClO4)在乙腈中回流并与PPh3反应得到了簇合物[(η5-C5Me5)2Mo2(μ3-S)4Cu2(PPh3)2 (ClO4)2·H2O.对其进行了红外、紫外光谱和X射线晶体结构测试.并使用Z扫描技术在532nm处测定了其在CH2Cl2溶液中的三阶非线性光学(NLO)性质.结果表明:该簇合物具有立方烷结构的簇阳离子,在溶液中表现出较强的三阶非线性吸收和自散焦效应。  相似文献   

6.
在B3LYP/6-31+G*水平上研究了外加电场对具有较好非线性光学性质的含羟乙基活性基团的噻唑生色分子结构和光谱与二阶非线性光学性质的影响.结果表明,随着外加电场的增大,最强红外吸收的强度明显减弱,最高占据轨道能量降低,最低空轨道能量升高,能隙增大,电子的最大吸收波长减小,二阶非线性光学性质减小.  相似文献   

7.
C2H4与TiCl4络合体系的CNDO/2计算   总被引:1,自引:1,他引:0  
采用CNDO/2法计算乙烯在Ziegler-Natta催化剂主体(TiCl4)上的络合反应机理.计算结果为:乙烯和四氯化钛单体处于优化构型时的能量分别为-17.0732a.u.和-68.8540a.u.,乙烯C=C双键的Muliken键级为1.173;络合体系处于优化构型时的能量为-86.0146a.u.,与吸附前单体乙烯和四氯化钛的能值相比,乙烯在四氯化钛上的吸附热为-229.3kJ/mol,乙烯C=C双键的Mul-liken键级为1.095,与络合前相比受到了削弱.通过计算所得的分子轨道能级、轨道特征以及Muliken约化重叠集居等数据,分析了催化剂的催化机理。  相似文献   

8.
一氧化氮供体S-亚硝基-N-乙酰基-DL-青霉胺(SNAP)对微生物生长具有显著的抑制效果. 为了进一步验证SNAP对微生物抗抑作用,本文通过亚硝化反应制备得到SNAP固体,并基于不同SNAP浓度验证其抗菌性能. 结果表明:(1)通过核磁和紫外表征, 我们成功制备得到SNAP;(2)SNAP对大肠杆菌、金黄色葡萄球菌(耐药/非耐药)和淋球菌均表现出明显的抑制作用且具有浓度依赖性,表明SNAP具有广谱抗菌特性. SNAP优良的抗菌特性使其及一氧化氮供体在抗抑菌领域有着广阔的应用前景.  相似文献   

9.
In this paper, the second-order nonlinear-optical coefficients of a series of conjugated substituted polyenes have been calculated by the semi-empirical CNDO/S-CI method, we have studied in detail the influence on the number of substituents, the location of the substituents and the conjugation length in molecules to the NLO coefficient β The results showed that the introduction of the electronic donor and acceptor groups and the increase in the distance between the substituents and the conjugated length may lead to enhanced NLO responses. It is also shown that the calculated ln β_(vec) is linear with the number of double bonds in planar and linear trans substituted polyenes. A saturation effect in substitution is also presented. Based on these discussion one can provide the theoritical guidelines for designing and synthesizing of molecules with larger NLO coefficients.  相似文献   

10.
本文主要研究以上薛定谔—麦克斯韦尔方程的径向解,并得到了其径向解的存在性和多重性结果。  相似文献   

11.
运用密度泛函理论(DFT)研究了5, 15-二(五氟苯基)-10-(2-氨基苯基)咔咯(F10Cor)及其金属(Mn、Cu、Ga)配位化合物的几何结构、电子吸收光谱和二阶非线性光学(NLO)性质.利用态求和的方法在CAM-B3LYP/aug-cc-pVDZ水平计算了咔咯配位化合物的二阶NLO系数(β0).计算结果表明:F10Cor及配位化合物的静态二阶NLO系数β0的大小顺序为F10CorCu(57.75×10-30 esu)、F10Cor(37.92×10-30 esu)、F10CorMn(27.10×10-30 esu)、F10CorGa(20.00×10-30 esu),这些咔咯配位化合物的二阶非线性光学响应主要源自于βy分量的贡献. F10CorCu的二阶NLO响应主要来源于β-HOMO-1→β-LUMO轨道跃迁,表现为2-氨基苯基与咔咯大环之间的配体内电荷转移(ILCT)跃迁.动态第一超极化率计算结果表明,在波长为1 907 nm入射光照下,F10Cor及金属配位化合物均未表现出强的色散效应,其动态二阶NLO系数(β1 907 nm)约为静态值β0的2倍,顺序为F10CorCu(103.94×10-30 esu)、F10Cor (60.60×10-30 esu)、F10CorMn(48.75×10-30 esu)、F10CorGa(34.39×10-30 esu).  相似文献   

12.
详细建立了PHEV动力总成系统的各个组件以及汽车行驶动力学的数学模型,其中对发动机和电机的建模提出了"基于三维特性图的准线性模型"的概念,同时深入研究了PHEV动力总成系统的电力辅助控制策略,并应用MATLAB/SIMULINK语言对EQ6110混合动力客车的动力总成系统进行了仿真研究,先后研究了不同SOC初值和不同循环试验标准下的仿真结果.  相似文献   

13.
简单图G和H的结合图G[H]的顶点集为V(G)×V(H),其中(u,v)和(u′,v′)相邻的充分必要条件是:或者uu′∈E(G)或者u=u′并且vv′∈E(H).研究了结合图G[H]的导出匹配可扩性,证明了若G和H是非平凡图,G是连通图,且G和H满足下列条件之一,则G[H]是导出匹配可扩的:(1) G和H中有一个是导出匹配可扩的;(2) G和H都有完美匹配;(3) G和H中一个有完美匹配,另一个有几乎完美匹配.  相似文献   

14.
在HCl一In2(S04)3一H2O体系中,恒定溶液总离子强度和In2(S04)3在溶液中的离子强度分数,应用经典的电动势方法测定无液体接界电池(A)在278.15—318.15K温度范围内的电动势:Pt,H2(101.325kPa)|HCl(mA),In2(S04)3(m2),H2O|AgCl—Ag(A)根据电池(A)的电动势数据,计算了混合溶液中HCl的活度系数γA,当指定温度和保持溶液中总离子强度恒定时,进一步讨论了HCl的活度系数与溶液中In2(S04)3的离子强度分数的关系,结果表明,在溶液总离子强度较低时,HCl的活度系数服从Harned规则.  相似文献   

15.
A Worsted Yarn Virtual Production System Based on BP Neural Network   总被引:6,自引:0,他引:6  
Back-Propagation (BP) neural network and its modified algorlthm are introduced. Two series of BP neural network models have been established to predict yarn properties and to deduce wool fiber qua/ides. The results from these two series of models have been compared with the measured values respectively, proving that the accuracy in both the prediction model and the deduction model is high. The experimental results and the corresponding analysis show that the BP neural network is an efficient technique for the quality prediction and has wide prospect in the application of worsted yam production system.  相似文献   

16.
The realization of all-optical switching, modulating and computing devices is an important goal in modern optical technology. Nonlinear optical materials with large third-order nonlinear susceptibilities (chi(3)) are indispensable for such devices, because the magnitude of this quantity dominates the device performance. A key strategy in the development of new materials with large nonlinear susceptibilities is the exploration of quasi-one-dimensional systems, or 'quantum wires'--the quantum confinement of electron-hole motion in one-dimensional space can enhance chi(3). Two types of chemically synthesized quantum wires have been extensively studied: the band insulators of silicon polymers, and Peierls insulators of pi-conjugated polymers and platinum halides. In these systems, chi(3) values of 10(-12) to 10(-7) e.s.u. (electrostatic system of units) have been reported. Here we demonstrate an anomalous enhancement of the third-order nonlinear susceptibility in a different category of quantum wires: one-dimensional Mott insulators of 3d transition-metal oxides and halides. By analysing the electroreflectance spectra of these compounds, we measure chi(3) values in the range 10(-8) to 10(-5) e.s.u. The anomalous enhancement results from a large dipole moment between the lowest two excited states of these systems.  相似文献   

17.
研究了基质组成、化学键结构对荧光材料(Y,Zn,Sr)3(P,VO4)2:Eu3+,Bi3+的发光性质和基质敏化的影响。实验表明在基质中引入Y—O—V直线链,对基质的吸收和发射跃迁、能量传递有着良好的敏化作用。从理论上探讨了能量传递机理。  相似文献   

18.
在函数类空间:W={u(x)=[sin f(r)eidθ,cos f(r)]∈H1(B,S2);u|坠B=g}中,研究Landau-Lifshitz型泛函Eε(u,B)=1/2∫ B︱▽u︱2dx+1/2ε2∫Bu23dx的径向极小元uε的渐近性态。通过建立径向极小元uε的H1局部收敛性,给出了u2ε3收敛到0的速度估计。  相似文献   

19.
本文以电力系统经典模型为基础,推导出了电力系统暂态稳定安全域的解析表达式,并提出了基于混合方法的发电机暂稳输出功率极限计算方法及快速求解该安全域的算法.算例表明,该暂态稳定安全域简单直观,计算快速.  相似文献   

20.
结合自洽反应场(SCRF)法、CPCM溶剂化模型,分别用密度泛函理论法B3LYP、TD-DFT/CAM-B3LYP和有限场(FF)法,对三聚氰胺分子在气相、氯仿以及甲醇溶液中的几何结构、电子吸收光谱、二阶极化率进行了系统的理论计算.结果表明,该分子为准八极结构,其强吸收峰在远紫外区,透光范围宽.最大吸收由两个近简并的激发态跃迁叠加而成,二者呈加和模式,对二阶极化率都有贡献.其几何结构、电子光谱和非线性光学(NLO)极化率都不同程度地呈现溶剂效应.高极性溶剂能显著增大其超极化率,而其最大吸收红移很小.在保持分子基本架构的前提下,通过增大供体与受体核之间的共轭桥,可以在保持良好透明性的前提下,增大超极化率,得到良好的NLO生色团.  相似文献   

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