Semiclean环及其扩张

对clean环进行了推广,研究了semiclean环,讨论了semiclean环的几个重要性质;证明了(1)R是semi-clean环;(2)R上的形式幂级数环R[[x]]是semiclean环;(3)R上的斜幂级数环R[[x;α]]是semiclean环等价;最后证明了,如果R是环,(S,≤)是严格偏序幺半群且对任意s∈S,都有0≤s,则[[RS,≤]]是semiclean环当且仅当R是semiclean环.     

Inverse Halogen Bonds Interactions Involving Br Atom in the Electronic Deficiency Systems of CH3⊕ … Br-Y (Y=H,CCH, CN,NC)

Inverse halogen bonds interactions involving Br in the electronic deficiency sys-tems of CH₃^⊕…Br-Y (Y=H, CCH, CN, NC) have been investigated by B3LYP/6-311++G(d, p) and MP2/6-311++G(d, p) methods. The calculated interaction energies with basis set super-position error correction of the four IXBs com-plexes are 218.87, 219.48, 159.18, and 143.05 kJ/mol (MP2/6-311++G(d, p)), re-spectively. The relative stabilities of the four complexes increased in the order:CH₃^⊕…BrCN3^⊕…BrNC3^⊕…BrH≈CH₃^⊕…BrCCH. Natural bond orbital theory analysis and the chemical shifts calculation of the related atoms revealed that the charges flow from Br-Y to CH₃^⊕. Here, the Br of Br-Y acts as both a halogen bond donor and an electron donor. Therefore, compared with conventional halogen bonds, the IXBs complexes formed between Br-Y and CH₃^⊕. Atoms-in-molecules theory has been used to investigate the topological properties of the critical points of the four IXBs structures which have more covalent content.     

可消偏序半群的可消偏序扩张与商序同态

引入偏序半群的商半拟序的概念,利用商半拟序给出了可消偏序半群上的偏序可扩张为可消偏序的充分条件.通过偏序半群的半拟序σ、模σ的闭半拟链,商半拟序和偏序扩张以及可消偏序半群的可消偏序扩张,对偏序半群的商序同态进行了刻画,得到了若干重要的结论.     

乙烯、乙炔和苯与氨基锂间的π型锂键相互作用

分别在DFT-B3LYP和MP2/6-311++G**水平上求得乙烯、乙炔和苯与氨基锂锂键复合物势能面上的3个几何构型. 频率分析表明,3个构型均为稳定构型. 计算结果表明,形成锂键复合物后,质子供体N(2)- Li(4)的键长明显增大,且其伸缩振动的频率发生了不同程度的红移. 分别在乙烯…氨基锂、乙炔…氨基锂和苯…氨基锂三种复合物中,经MP2/6-311++G**水平计算的同时含基组重叠误差(BSSE)和零点振动能校正的单体间锂键相互作用能分别为-26.04、-24.86 和 -30.02 kJ·mol-1. 自然键轨道理论（NBO）分析表明单体间的弱相互作用属于π-s型锂键.     

An efficient algorithm for the generalized centro-symmetric solution of matrix equation <Emphasis Type="Italic">A X B</Emphasis> = <Emphasis Type="Italic">C</Emphasis>

In this paper, an iterative algorithm is constructed for solving linear matrix equation AXB = C over generalized centro-symmetric matrix X. We show that, by this algorithm, a solution or the least-norm solution of the matrix equation AXB = C can be obtained within finite iteration steps in the absence of roundoff errors; we also obtain the optimal approximation solution to a given matrix X ₀ in the solution set of which. In addition, given numerical examples show that the iterative method is efficient.     

Solvability of matrix Riccati equations

The paper is aimed at studying solvability conditions for the quadratic matrix Riccati equation that arises in connection with the Chapman–Enskog projection for the Cauchy problem and the mixed problem for moment approximations of kinetic equations. The structure of the matrix equation allows for the formulation of necessary and sufficient conditions for the existence of solutions in terms of eigenvectors and associated vectors of the coefficient matrix.     

用坐标法确定原子(离子)基态

通过对等效电子引入ms、ml坐标系及坐标,给出了用坐标法确定原子(离子)基态的方法并示例.结果显示:此法原理清楚,使用便捷,容易掌握且结果正确,同已有方法相比,有明显的优点.用此法对103种元素的原子基态确定结果与《原子物理学》(杨福家著,2002年高等教育出版社出版)所给结果完全一致.     

2-苯基苯并噁唑的光解反应

聚对苯撑苯并二噁唑(PBO)纤维对光较为敏感,在紫外光照射下会发生降解.本文研究了该纤维的单体2-苯基苯并噁唑(PO)的初级光化学反应机理.当PO分子吸收一个光子而跃迁到第一激发态后,克服25.59kJ·mol-1能垒而越过过渡态,此时噁唑环打开,且两个苯环形成大约90°的二面角而得到产物,该产物可进一步与空气中的水发生次级反应.计算结果表明在第一激发态上噁唑开环反应很容易,但在基态势能面并没有发现噁唑的开环路径.分子中的原子(AIM)的计算结果与上述分析过程相吻合.     

图的1-因子数目的递推求法

首先对图的1-因子进行分类,求出每一类1-因子数目的递推关系式;然后对各类1-因子数目的递推式进行求和,得到一组有相互联系的递推关系式;利用递推式之间的相互关系,消去不需要的,得到图的1-因子数目的递推关系式;最后求出此递推式的公式解。     

壳聚糖铜配合物与鲱鱼精DNA的相互作用

采用循环伏安法和紫外吸收光谱研究了壳聚糖铜配合物与鲱鱼精DNA的相互作用。结果发现:随壳聚糖铜浓度的增加,DNA的紫外吸收光谱呈增色效应和较小的红移;壳聚糖铜离子在电极上的反应主要由扩散过程控制,加入DNA后氧化还原峰电流降低,且式量电位正移,说明壳聚糖铜与DNA以嵌入方式生成一种非电活性超分子复合物,导致壳聚糖铜配合物的峰电流降低。实验结果表明壳聚糖铜与DNA的相互作用模式为嵌入和静电混合作用。