On matching and total domination in graphs

A set M of edges of a graph G is a matching if no two edges in M are incident to the same vertex. A set S of vertices in G is a total dominating set of G if every vertex of G is adjacent to some vertex in S. The matching number is the maximum cardinality of a matching of G, while the total domination number of G is the minimum cardinality of a total dominating set of G. In this paper, we investigate the relationships between the matching and total domination number of a graph. We observe that the total domination number of every claw-free graph with minimum degree at least three is bounded above by its matching number, and we show that every k-regular graph with k?3 has total domination number at most its matching number. In general, we show that no minimum degree is sufficient to guarantee that the matching number and total domination number are comparable.     

气相色谱法测定眼药水中琥珀酸钠的含量

用气相色谱法测定眼药水中琥珀酸钠的含量。样品减压蒸干后,经酸化使琥珀酸钠变成琥珀酸,加入丙二酸进行衍生化反应,形成琥珀酸丁二酯和丙二酸丁二酯,以DEGS玻璃填充柱为色谱柱,用FID检测,进行气相色谱分析,结果令人满意。     

AT-free图的配对控制集算法

本文给出了配对控制集在AT-free图的BFS-树上分布的结构性质．利用这些性质，我们给出了求解AT-free图类最小配对控制集的多项式时间算法．     

Preparation of a Polymer Monolithic Column Using Ionic Liquid as Porogen and Its Application in Separations of Proteins and Small Molecules

A polymer-based monolithic column was prepared for high-performance liquid chromatography (HPLC), using ionic liquids as porogen within the confines of a stainless steel column (50 × 4.6 mm i.d.). In the process, 1-butyl-3-methylimidazolium chloride and dodecyl alcohol were used as bi-porogens, vinyl ester resin as the monomer, ethyleneglycol dimethacrylate as the crosslinker, CCl₄ as the initiator, and FeCl₂ as the catalytic agent to prepare the polymer-based monolithic column. Scanning electron microscopy, nitrogen adsorption–desorption instrument, and mercury intrusion porosimetry were used to assay the characteristics of the monolith, respectively. The optimized monolith showed uniform structure and good permeability. Then, the column was used as the stationary phase of HPLC to separate standard proteins and human plasma with gradient elution. Besides, the monolith was used to separate aromatic compounds from the mixture. The results showed that the addition of IL could effectively improve the structure of monoliths prepared by atom transfer radical polymerization technique. The results also suggested that this kind of monolith could be used as a simple, cheap and effective stationary phase for HPLC.     

黑龙江省的界河坍塌地质灾害及其防治对策

界河坍塌是黑龙江省特殊的、主要的地质灾害,也是当前亟待解决的问题。本文总结了黑龙江省的两条主要界河—黑龙江和乌苏里江的塌岸状况;说明了界河坍塌的分布规律;论证了界河坍塌的形态类型;探讨了界河坍塌的形成机制;分析了界河坍塌的原因;最后提出了防止界河坍塌的一系列对策。     

Performance of a satellite-to-ground downlink coherent lasercom system with random tracking error of receiver

We analyze the performance of a satellite-to-ground downlink coherent lasercom system taking into account the combined effects of atmospheric wavefront aberration and tracking error of the receiver. We revise the wavefront phase variance in the case where the tracking error of the receiver terminal is present. We consider the example of the BPSK modulation scheme and show that the tracking error of the receiver terminal greatly increases the bit error probability of the coherent system. We show the optimum aperture diameter of the receiver. This study can benefit the satellite-to-ground downlink coherent lasercom system design.     

Crystallographic report: Crystal structure of a homoleptic lanthanide guanidinate complex: [Ph2NC(NCy)2]3Yb·2PhCH3

The title complex, [Ph₂NC(NCy)₂]₃Yb·2PhCH₃ is a monomer with a six‐coordinate ytterbium center ligated by six nitrogen atoms of three chelating bidentate guanidinate ligands. The coordination geometry around the lanthanide ion is best described as a distorted trigonal prism. Copyright © 2005 John Wiley & Sons, Ltd.     

MNA/PMMA有机薄膜光波导

研究出MNA/PMMA有机薄膜光波导。用棱镜耦合器进行了波导参数的测量,发现薄膜呈现各向异性,有较大的双折射。     

IMGS方法对于,H -矩阵的若干令人满意的改进

该文给出线性方程组改进的Gauss-Seidel迭代法（被称之为IMGS方法）对于H -矩阵的收敛性定理,并且对其参数a_i与SOR迭代法的参数ω的取值范围进行了比较. 所用方法及所得结论优于近年来相关结论,并且表明这种IMGS方法对,H -矩阵是有效的.     

亚甲蓝分光光度法测定水体中的阴离子表面活性剂

利用三氯甲烷萃取水体样品中的阴离子表面活性剂，用50mL比色管代替50mL容量瓶对三氯甲烷萃取液进行定容，以亚甲蓝分光光度法进行测定。该方法操作简便，测定阴离子表面活性剂的线性范围为0．150～1．70mg／L，检出限为0．050mg／L，样品加标回收率为89％～98％。