4种等温物态方程适用性的比较研究

 通过分析现有文献，认为4种两参数的物态方程在高压物理研究中较为流行，它们是Vinet、Baonza、Morse和Born-Meyer（BM）方程。将这4种方程用于拟合50种材料的实验压缩数据，得出了零压下压缩模量及其一阶压力导数的优化取值，并计算了4种方程的平均压力误差。结果表明，Morse方程的精度最高，对50种材料的平均拟合误差为0.557 6%；BM方程次之，平均误差为0.615 1%；Vinet和Baonza方程的误差大一些，分别为0.788 9%和0.833 3%。对8种典型材料计算了压力误差随压强变化的曲线，所得结果与平均误差的趋势一致，也是Morse方程的精度最高。在宽广压力范围的高压物态方程研究中，推荐使用Morse方程。     

Generalized fractional programming duality: A parametric approach

Using a parametric approach, duality is presented for a minimax fractional programming problem that involves several ratios in the objective function.The first author is thankful to Natural Science and Engineering Research Council of Canada for financial support through Grant A-5319, and the authors are thankful to the anonymous referees for useful suggestions.     

中高分辨力遥感图像中飞机目标自动识别算法研究

提出了一种中高分辨力的航空航天遥感图像中飞机目标快速自动识别的新算法。在分割和分类过程中充分利用飞机目标的先验知识,提出了一种改进区域分割方法,并应用树分类器对飞机目标进行自动识别。所提出的改进区域分割方法较好地实现了区域分割中阈值的准确自动选取,克服了复杂背景图像中小目标的全局阈值自动分割的失效问题。采用二叉树分类器,通过提取简单的目标几何特征,分层进行种类识别,提高了识别速度,降低了漏检率和虚警率。运用该方法进行了实验。结果表明,识别率达到了100%。     

多元线性回归应用于近代物理实验

本文介绍非线性方程转化直线性方程和多元线性回归法来分析近代物理实验中塞曼效应分裂干涉圆环多处选点测量的处理过程。     

标的资产服从几何分数布朗运动的期权定价

本文在M ogens B ladt和T ina H av iid R ydberg无市场假设,仅利用价格过程的实际概率的期权保险精算定价模型的基础上,得出了标的资产服从几何分数布朗运动的欧式期权定价公式,并说明了几何布朗运动是本文的一种特殊情况.     

f(R) theories of gravity in the Palatini approach matched with observations

We investigate the viability of f(R) theories in the framework of the Palatini approach as solutions to the problem of the observed accelerated expansion of the universe. Two physically motivated popular choices for f(R) are considered,: power law, f(R) = β R ⁿ , and logarithmic, f(R) = α ln R. Under the Palatini approach, both Lagrangians give rise to cosmological models comprising only standard matter and undergoing a present phase of accelerated expansion. We use the Hubble diagram of type Ia Supernovae and the data on the gas mass fraction in relaxed galaxy clusters to see whether these models are able to reproduce what is observed and to constrain their parameters. It turns out that they are indeed able to fit the data with values of the Hubble constant and of the matter density parameter in agreement with some model independent estimates, but the today deceleration parameter is higher than what is measured in the concordance ΛCDM model.     

汇率变动对进出口影响的实证分析

本文研究了汇率变动对中国进出口的影响,在间接标价法下对论文中所用到的汇率贬值改善国际收支的三个必要条件给出了结论和证明(弹性法);在经济理论及经验研究的基础上,建立了论文中所需要的所有模型并且根据模型对相关经济问题利用现代计量经济学方法进行了实证研究.通过实证研究我们得到的结论是:我国满足汇率贬值改善国际收支的必要条件;出口增加有助于GDP的增长,进口增加对GDP的影响是反向的且随着进口增加这种影响逐渐减弱最终趋于零.     

高强混凝土弯压极限应变试验研究与计算

由于混凝土材料理化特性的差异,高强混凝土的弯压极限应变明显地小于普通混凝土,依据试验结果分析了高强混凝土的弯压极限应变变化规律,并给出了它的计算公式.     

Variational extension of the mean spherical approximation to arbitrary dimensions

We generalize a variational principle for the mean spherical approximation for a system of charged hard spheres in 3D to arbitrary dimensions. We first construct a free energy variational trial function from the Debye-Hückel excess charging internal energy at a finite concentration and an entropy obtained at the zero-concentration limit by thermodynamic integration. In three dimensions the minimization of this expression with respect to the screening parameter leads to the mean spherical approximation, usually obtained by solution of the Ornstein-Zernike equation. This procedure, which interpolates naturally between the zero concentration/coupling limit and the high-concentration/ coupling limit, is extended to arbitrary dimensions. We conjecture that this result is also equivalent to the MSA as originally defined, although a technical proof of this point is left for the future. The Onsager limitT ΔS ^MSA /ΔE ^MSA → 0 for infinite concentration/coupling is satisfied for all d ≠ 2, while ford=2 this limit is 1. On leave from Department of Physics, University of Puerto Rico, Mayagüez Campus, Mayagüez, Puerto Rico, 00681.     

Modeling of drug molecule orientation within a receptor cavity in the BiS algorithm framework

The BiS algorithm is suggested for modeling the drug molecule orientation within a receptor cavity. It is based on the assumption of complementarity of the field created by biologically active compounds and the field of the responsive receptor. The comparison of predicted orientations of various biologically active compounds on the relevant receptors with the data of X-ray structural studies (Protein Data Bank) reveals that the results obtained with this approach surpasses those reported in the literature. The suggested technique made it possible to elucidate the details of the action mechanism of DNA antimetabolites, dihydrofolate reductase inhibitors. The dependence of the activity on the structural parameters of “ligand-receptor” complexes is determined.