Crystallographic report: Bis[tris(2‐methyl‐2‐phenylpropyl)tin] piperazinyldithiocarbamate

The centrosymmetric structure of bis[tris(2‐methyl‐2‐phenylpropyl)tin]piperazinyldithiocarbamate contains four‐coordinated tin and monodentate dithiocarbamate ligands. Copyright © 2004 John Wiley & Sons, Ltd.     

Scale height determination of spiral galaxies

The method adopted here is based on the rigorous solution of Poisson’s equation for logarithmic disturbance density within finite thickness galaxies. After their spiral arms are fitted directly with logarithmic spirals, the morphological parameters, scale heights and their relative errors for 32 spiral galaxies, such as NGC4814, are obtained.     

线性方程组的一种解法

本文利用矩阵的分块运算法则，给出求线性方程组ＡｍｎＸｎ＝Ｏｍ及ＡｍｎＸｎ＝ｂｍ一种方法．     

Polymer encapsulation of yttrium oxysulfide phosphorescent particles via miniemulsion polymerization

Yttrium oxysulfide upconverting phosphor particles can absorb infrared light and emit dopant‐dependent visible phosphorescence. This unique optical property has been used for particle‐based immunoassay applications. In this study, upconverting phosphor particles were encapsulated with a functionalized polymer (carboxylated polystyrene) shell layer via several approaches, which included the following: (1) the physical adsorption of the carboxylated polystyrene polymer onto the phosphor surfaces, (2) the miniemulsification of the preformed carboxylated polystyrene in a solvent in the presence of the phosphor particles and the subsequent stripping off of the solvent, and (3) the miniemulsification and miniemulsion copolymerization of styrene and methacrylic acid in the presence of the phosphor particles with hexadecane as a costabilizer in combination with a surfactant (sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, or sodium dihexyl sulfosuccinate). Miniemulsion technology proved to be the most effective method for forming a functionalized polymeric nanoshell surrounding the phosphor particles. The morphology of the encapsulated phosphor particles was found to vary from symmetric core–shell (i.e., a uniform nanoshell layer with varying shell thicknesses), asymmetric core–shell, dumbbell‐like, or raspberry‐like partial encapsulation to multiparticle encapsulation. The amount of multiparticle encapsulation could be reduced by the postaddition of a surfactant, but it could not be eliminated completely. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1038–1054, 2007     

The Convergences of Bivariate Integral Jackson Interpolating Operators in Orlicz Spaces

ＴｈｅＣｏｎｖｅｒｇｅｎｃｅｓｏｆＢｉｖａｒｉａｔｅＩｎｔｅｇｒａｌＪａｃｋｓｏｎＩｎｔｅｒｐｏｌａｔｉｎｇＯｐｅｒａｔｏｒｓｉｎＯｒｌｉｃｚＳｐａｃｅｓ尚增科，王有一，盛保怀ＴｈｅＣｏｎｖｅｒｇｅｎｃｅｓｏｆＢｉｖａｒｉａｔｅＩｎｔｅｇｒａｌＪａｃ...     

形体老化与疾病的非线性主成分分析

本文把 5个形体老化指标及 13种慢性病指标分别做成两个综合指标 ,再去研究人体老化、疾病与性别及年龄的关系。文中使用非线性主成分法及指出一般线性主成分法的局限性     

光子扫描隧道显微镜的光电成像系统研究

本文论述了光子扫描隧道显微镜（ＰＳＴＭ）的显微成像机理、成像规律，针对具体的物理模型进行数值模拟计算，并得到了与实际探测相一致的场分布规律。采用自行研制的光子扫描隧道显微镜（ＰＳＴＭ）的显微实验系统对多种样品进行了表面显微成像研究，获得了关于样品表面三维立体图像信息，通过多种图像处理手段对原始图像进行后期处理，得到了更具视觉效果、更为逼真的样品表面图像。     

Vector sampling expansions in shift invariant subspaces

Multi-input multi-output (MIMO) sampling scheme which is motivated by applications in multi-channel deconvolution and multi-source separation has been investigated in many aspects. Common for most of results on MIMO systems is that the input signals are supposed to be band-limited. In this paper, we study vector sampling expansions on general finitely generated shift-invariant subspaces. Necessary and sufficient conditions for a vector sampling theorem to hold are given. We also give several examples to illustrate the main result.     

电子助进化学气相沉积金刚石中发射光谱的蒙特卡罗模拟

采用蒙特卡罗方法，对源料气体为CH4/H2混合气的电子助进化学气相沉积（EACVD）中 的氢原子(H)、碳原子(C)以及CH基团的发射过程进行了模拟.研究了CH4浓度、反应室气压 和衬底偏压等工艺参数对发射光谱及成膜的影响.研究发现，CH基团可能是有利于金刚石薄 膜生长的活性基团，而碳原子不是；偏压的升高可提高电子平均温度及衬底表面附近氢原子 的相对浓度；通过氢原子谱线可测定电子平均温度并找到最佳成膜实验条件.该结果对EACVD 生长金刚石薄膜过程中实时监测电子平均温度，有效控制工艺条件，生长出高质量的金刚石 薄膜具有重要的意义. 关键词： 蒙特卡罗模拟 金刚石薄膜 发射光谱     

A Discrete Lagrangian-Based Global-Search Method for Solving Satisfiability Problems

Satisfiability is a class of NP-complete problems that model a wide range of real-world applications. These problems are difficult to solve because they have many local minima in their search space, often trapping greedy search methods that utilize some form of descent. In this paper, we propose a new discrete Lagrange-multiplier-based global-search method (DLM) for solving satisfiability problems. We derive new approaches for applying Lagrangian methods in discrete space, we show that an equilibrium is reached when a feasible assignment to the original problem is found and present heuristic algorithms to look for equilibrium points. Our method and analysis provides a theoretical foundation and generalization of local search schemes that optimize the objective alone and penalty-based schemes that optimize the constraints alone. In contrast to local search methods that restart from a new starting point when a search reaches a local trap, the Lagrange multipliers in DLM provide a force to lead the search out of a local minimum and move it in the direction provided by the Lagrange multipliers. In contrast to penalty-based schemes that rely only on the weights of violated constraints to escape from local minima, DLM also uses the value of an objective function (in this case the number of violated constraints) to provide further guidance. The dynamic shift in emphasis between the objective and the constraints, depending on their relative values, is the key of Lagrangian methods. One of the major advantages of DLM is that it has very few algorithmic parameters to be tuned by users. Besides the search procedure can be made deterministic and the results reproducible. We demonstrate our method by applying it to solve an extensive set of benchmark problems archived in DIMACS of Rutgers University. DLM often performs better than the best existing methods and can achieve an order-of-magnitude speed-up for some problems.