含1,3-二硫-2叶立德烯的系列有机发色团的二阶非线性光学性质的理论研究

设计了12个含有1,3-二硫-2叶立德烯的具有二阶非线性光学性质的有机发色团,对所研究分子用AM1方法进行几何构型优化,用INDO/CI方法获得基态到各激发态的垂直跃迁能和振子强度,即电子光谱;在此基础上用SOS公式计算系列分子的二阶非线性光学系数β_ijk,并从微观上对这一系列分子进行比较,为进一步探索综合性能较好的NLO有机物提供了理论指导.     

光通路层的功能模型

本文提出亲层功能模型以对光传送网的层网络进行建模.此模型可以作为通用结构模型的扩展而引入G.805.此外,还举例说明了采用亲层功能模型对光分插复用器(OADM)进行建模和为光网元提供所需的透明连接的方法.     

Theoretical studies of the reactions of O(~3p) with halogenated methyl (Ⅰ)——Reaction mechanism of the O(~3p) CH_2Cl reaction

The reaction of O(~3P) with CH_2Cl radical has been studied using ab initio molecular orbital theory. G2 (MP2) method is used to calculate the geometrical parameters, vibrational frequencies and energies of various stationary points on the potential energy surface. The reaction mechanism is revealed. The addition of O(~3P) with CH_2Cl leads to the formation of an energy rich intermediate OCH_2Cl which can subsequently undergo decomposition or isomerization to the final products. The calculated heat of reaction for each channel is in agreement with the experimental value. The production of H CHClO and Cl CH_2O are predicted to be the major channels. The overall rate constants are calculated using transition state theory on the basis of ab initio data. The rate constant is pressure independent and exhibits negative temperature dependence at lower temperatures, in accordance with the experimental results.     

Study on the Quantum FK Model

In this paper, we present a variational method which is suitable for investigating the quantum fienkel-Kontorova model. For the cases of using the coherent state and the squeezed state as the trial wave functions of the ground states, the quantum Hamiltonians and the quantum maps are given. For the second case, we present the phase diagram and devil's stairs using the effective potential method, determine the critical points K_c for different l using Greene's criterion. The results given in the present paper are qualitatively consistent with those of the numerical experiments.^[6]     

一个一维CI相变模型的进一步研究

对一个一维CI相变模型进行进一步研究。外势周期D具有一个临界值Dc。D < c时的相图与D > c时的相图非常地不同。当D < c时,相图随D而变化,且在D的大部分区域显示出Farey树结构。当D > c时,相图不再变化,且不满足Farey树结构。通过有效势F(u)研究了相变过程。     

Theoretical investigation of the heterofullerenes C59N and C69N and their dimers

The heterofullerenes C₅₉N and C₆₉N and their dimers are examined by the intermediate neglect of differential overlap (INDO/1 and INDO/S) models. The results confirm the stability of the (C₅₉N)₂ and (C₆₉)₂ (C_2h) isomers with a 6–6 closure fusion link between the two monomers. The nearest neighbor C of nitrogen, at the hexagon–hexagon fusion in C₅₉N and in C₆₉N where the N replaces one C in the pentagon of the fullerene has the largest electronic spin density, and this is where the two radicals of C₅₉N or C₆₉N link to form dimers. Also the dimers readily dissociate to free radical monomers to react regioselectively with other reagents. The electronic spectra of the radicals are similar to those of the dimers, which suggest essentially identical electronic structures. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 78: 422–436, 2000     

Full‐CI quantum chemistry using the density matrix renormalization group

We describe how density matrix renormalization group (DMRG) can be used to solve the full configuration interaction problem in quantum chemistry. As an illustration of the potential of this method, we apply it to a paramagnetic molecule. In particular, we show the effect of various basis set, the scaling as the fourth power of the size of the problem, and compare the DMRG with other methods. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 79: 331–342, 2000     

Nonrelativistic energies for the Be atom: Double-linked Hylleraas–CI calculation

Hylleraas–configuration interaction (CI) calculations have been carried out with double-linked basis sets for the Be atom. Our best upper bound for the ¹S ground state is E₀ = −14.6673547E_h. Furthermore, upper bounds for the two lowest excited ¹S states have been calculated. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 66 : 241–247, 1998     

Possible Thermal-triplet Nitrosobenzene Reaction

The reactions of nitrosobenzenes have been the subject of much study and many publications. However, not unlike other projects, at least as many questions have been raised as have been answered. There are several nitrosobenzene reactions which are of particular interest to us and we would like to raise a few more questions concerning their mechanisms. Nitrosoarenes are reported to undergo cycloaddition reactions with diphenylketene to yield 3 or 4-oxazetidinones depending upon ring substituents in the nitrosoarene.¹ More recently nitrosoarenes have been shown to undergo a similar cycloaddition reaction with ketenimines (nitrogen analogs of ketenes), but only the 3-iminosubstituted oxazetidine (the isomer unexpected from polar theory) is obtained regardless of ring substituents in the nitrosoarene.² A related problem is the 1,4-cycloaddition of nitrosobenzene and cycloheptadiene and the 1,6-cycloaddition of nitrosobenzene and cycloheptatriene.^3,4 The observed differences in products have been attributed to a variation in the mode of reaction.⁴ Concerted processes were postulated to give 1,4-addition while stepwise processes lead to 1,6-addition.