多晶X射线衍射测量结果的一些影响因素

讨论了多晶X射线衍射测量中实验结果的一些影响因素.分别对粉末样品自身颗粒的大小、粉末装填到样品架中所处的表面平整度以及少量样品采用横式填充还是竖式填充等问题进行了分析和探讨.结果表明,在X射线衍射分析测量中,要想得到理想的衍射数据,试样颗粒应小于50μm,而且装填后样品与样品架表面保持平齐,对少量或微量试样应采取横式填充法.     

影响离子色谱测量准确性的因素

介绍了离子色谱测量过程中色谱条件的变化、样品前处理方法和操作过程等因素对测量结果准确性的影响,提出了相应的解决措施和校准方法.以实际样品测定为例介绍了样品前处理过程中待测组分浓度和形态的变化,对定量分析结果造成的误差及修正方法.     

动态光散射法测量颗粒粒径的溯源性

分别对动态光散射粒径测量仪的入射波长、散射角度、测量池温度进行校准,并对影响测量结果准确性各因素的不确定度分量进行了评价,校准后动态光散射仪的测量结果可溯源至国家计量标准。为消除多重散射、颗粒间相互作用、颗粒粒径分布对动态光散射测量结果的影响,建立了动态光散射测量结果修正方法。其中为消除多重散射及颗粒间相互作用的影响,需采用多浓度测量或线性回归的方法得到特定浓度下的颗粒粒径;为修正颗粒粒径分布对动态光散射测量结果的影响,需先采用SEM方法准确测量颗粒粒径分布,然后根据光强加权动力学平均粒径和数量平均粒径的理论公式,得到二者之间的差异。     

Theoretical Studies on the Reaction Mechanism of AsCl3 with H2 in the Vapor Phase Epitaxy of GaAs

The reaction mechanism of AsCl3 with H2 has been studied by using the method of BHandHLYP in Density Functional Theory (DFT) at the 6-311G** basis set. The transition state of each reaction is verified via the analysis of vibration mode and Intrinsic Reaction Coordinate (IRC). Meanwhile,single-point energy has been calculated at the QCISD(T)/6-311G** level,and the zero-point energy correction has been made to the total energy and reaction energy barrier. It shows that AsCl3 reacts with H2 to first result in AsHCl2 which may incline to self-decompose and finally afford the product As2,or continue to react with H2 to provide the product AsH3. The computing result demonstrates that the former is the main reaction channel.     

Hydrothermal Synthesis, Crystal Structure and Electrochemical Properties of Complex Cu(α-Furacrylic acid)2(phen)

The title complex (C26H18CuN2O6, Mr=517.96) has been synthesized by the reaction of α-furanacrylic acid with 1,10-phenanthroline (phen) in the solvent mixture of water and methanol. Crystal data: monoclinic, space group C2/c with a=2.2927(4), b=1.01248(18), c=1.05061(18) nm, β=111.188(3)°, V=2.274(7) nm3, Dc=1.513 g/cm3, Z=4, F(000)=1060,μ=1.007mm-1, R=0.0320 and wR=0.0781. The crystal structural analysis shows that the copper atom is coordinated with four oxygen atoms from two α-furacrylic acids and two nitrogen atoms from 1,10-phenanthroline, giving a distorted octahedral coordination geometry. The result of electrochemical analysis shows that the electron transfer in the electrode reaction is quasi-reversible.     

Une remarque sur l'orthogonalité de l'image au noyau d'une dérivation généralisée

In this paper we introduce the notion of the pair of operators having the Fuglede-Putnam property in a two-sided ideal of . The characterization of this class allows us to generalize the recent result of F. Kittaneh. We also give some applications of this result.

     

A condition on the value function both necessary and sufficient for full regularity of minimizers of one-dimensional variational problems

We study two-point Lagrange problems for integrands :

 

Under very weak regularity hypotheses [ is Hölder continuous and locally elliptic on each compact subset of ] we obtain, when is of superlinear growth in , a characterization of problems in which the minimizers of (P) are -regular for all boundary data. This characterization involves the behavior of the value function : defined by . Namely, all minimizers for (P) are -regular in neighborhoods of and if and only if is Lipschitz continuous at . Consequently problems (P) possessing no singular minimizers are characterized in cases where not even a weak form of the Euler-Lagrange equations is available for guidance. Full regularity results for problems where is nearly autonomous, nearly independent of , or jointly convex in are presented.

     

A dynamic Euler–Bernoulli beam equation frictionally damped on an elastic foundation

This paper deals with a dynamic Euler–Bernoulli beam equation. The beam relies on a foundation composed of a continuous distribution of linear elastic springs. In addition to this time dependent uniformly distributed force, the model includes a continuous distribution of Coulomb frictional dampers, formalized by a partial differential inclusion. Under appropriate regularity assumptions on the initial data, the existence of a weak solution is obtained as a limit of a sequence of solutions associated with some physically relevant regularized problems.     

功能梯度材料Timoshenko梁的热过屈曲分析

研究了功能梯度材料Timoshenko梁在横向非均匀升温下的热过屈曲．在精确考虑轴线伸长和一阶横向剪切变形的基础上,建立了功能梯度Timoshenko梁在热-机械载荷作用下的几何非线性控制方程,将问题归结为含有7个基本未知函数的非线性常微分方程边值问题A·D2其中,假设功能梯度梁的材料性质为沿厚度方向按照幂函数连续变化的形式．然后采用打靶法数值求解所得强非线性边值问题,获得了横向非均匀升温场内两端固定Timoshenko梁的静态非线性热屈曲和热过屈曲数值解．绘出了梁的变形随温度载荷及材料梯度参数变化的特性曲线,分析和讨论了温度载荷及材料的梯度性质参数对梁变形的影响．结果表明,由于材料在横向的非均匀性,均匀升温时的梁中存在拉-弯耦合变形．     

中小企业流程再造实施效果定量分析

本通过分析研究,建立模糊评价中小企业EPR应用效果的指标体系,应用模糊综合评价和层次分析法构造了中小企业实施BPR效果的结构模型,并以实例进行应用分析。