蒙特卡罗方法计算定积分的进一步讨论

介绍了蒙特卡罗方法计算定积分的原理和方法.给出了用蒙特卡罗方法计算定积分的一个简单证明,从而揭示了蒙特卡罗方法和定积分定义间的内在联系.针对蒙特卡罗方法收敛慢的特点,提出将蒙特卡罗方法与相应的数值计算方法相结合,提高计算结果的精度.此外,将蒙特卡罗方法推广到反常积分上去.     

GI~X/M~b/1/N排队系统

本文主要研究了顾客一般独立批到达、指数批服务、缓冲器容量有限的单个服务器的排队系统，本文首先使用补充变量和嵌入马氏链的方法，在部分拒绝和全部拒绝情形下，得到系统排队队长的稳态分布，进而得到相应的性能指标，如系统的平均排队长、平均等待时间、损失概率等．其次对等待时间进行了分析．     

福利院人群微量元素第三年度观察与分析

微量元素检测及临床观察是在深圳市社会福利中心（福利院）人群中开展了三年的市级科研项目，通过了解这些人群体内6种微量元素含量，为微量元素与健康及相关性疾病的临床研究提供科学依据。与上年度比较，福利院人群体内的有益微量元素普遍有所下降，低铁、低钙，尤其以低钙明显，临床发病率、住院率有所上升，特别是肠道疾病明显升高。福利院需要继续改善生活环境，增加富含有益微量元素饮食；疾病要以预防为主，膳食合理，营养均衡，微量元素检查应列为常规项目。     

溅射Al-C-O/Al太阳选择性吸收涂层

设计计算了以Al为底层的多层Al-C-O的太阳吸收涂层。运用直流磁控溅射制备了这种Al-C-O/Al吸收涂层。理论计算与实验测量的结果基本一致。经真空中烘烤后,涂层的Al-C-O/Al太阳吸收率α≈0.92,室温热发射率ε≈0.04,具有优良的光谱选择性。由于使用单个溅射靶,简化了溅射系统,提高了靶溅射的利用率。 关键词：     

Spin flip inelastic scattering in electron energy loss spectroscopy of a ferromagnetic metal

A model ferromagnetic metal is used to calculate the spin-polarization which occurs during inelastic electron-metal scattering with the production of an electron-hole pair. The polarization is found to have contributions from unequal spin-flip as well as non-flip energy loss rates. Our results indicate an asymmetry of the order of a few percent with parameters roughly modelling iron.     

The computations of Einstein-Kähler metric of Cartan-Hartogs domain

In this paper, we compute the complete Einstein-Kähler metric with explicit formula for the Cartan-Hartogs domain of the fourth type in some cases. Under this metric the holomorphic sectional curvature is given, which intervenes between −2k and −1. This is the sharp estimate.

     

MATLAB语言在X射线衍射谱图处理中的应用

利用MATLAB语言编写了X射线衍射数据处理程序,使之能够导人到Materials Studio软件,进行粉末晶面指标化以及粉末精修等后续处理.处理程序简单易懂,可作为其他测试数据格式转换程序的参考.     

Synthesis and characterization of well‐defined polystyrene and poly(ε‐caprolactone) hetero eight‐shaped copolymers

Well‐defined hetero eight‐shaped copolymers composed of polystyrene (PS) and poly(ε‐caprolactone) (PCL) with controlled molecular weight and narrow molecular weight distribution were successfully synthesized by the combination of ring‐opening polymerization, ATRP, and “click” reaction. The synthetic procedure involves three steps: (1) preparation of a tetrafunctional PS and PCL star copolymer with two PS and two PCL arms using the tetrafunctional initiator bearing two hydroxyl groups and two bromo groups; (2) synthesis of tetrafunctional star copolymer, (α‐acetylene‐PCL)₂(ω‐azido‐PS)₂, by the transition of terminal hydroxyl and bromo groups to acetylene and azido groups through the reaction with 4‐propargyloxybutanedioyl chloride and NaN₃ respectively; (3) intramolecular cyclization reaction to produce the hetero eight‐shaped copolymers using “click” chemistry under high dilution. The ¹H NMR, FTIR, and gel permeation chromatography techniques were applied to characterize the chemical structures of the resulted intermediates and the target polymers. Their thermal behavior was investigated by DSC, and their crystallization behaviors of PCL were studied by polarized optical microscopy. The decrease in chain mobility of the eight‐shaped copolymers restricts the crystallization of PCL and the crystallization rate of PCL is slower in comparison with their corresponding star precursors. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6496–6508, 2008     

快度分布与多重数的关系以及非衍射强子过程的随机性质

本文从对撞机(SPS)的实验结果出发,分析了强子-强子非衍射过程的机制。假定末态强子分成三个快度区域产生,它们的横能量随机地从入射粒子的动能中取得。而它们的纵动量等几率地分布,就能得到符合于实验的多重数分布和快度分布,以及快度分布对多重数的依赖关系。这表明,非衍射强子过程在两个相互垂直的方向上都有随机性。