On the Asymptotic Behavior of the Harmonic Renewal Measure

We study the tail behavior of the harmonic renewal measure U= _n=1 (1/n)F ^n* where F is a probability distribution with finite negative mean and F ⁿ * is the n-fold convolution of F. As an application of the obtained result on U, we give alternative proofs of some known results concerning the tail behavior of the supremum and the first positive sum of a random walk with negative drift.     

模的r-比较与r-幂比较

本文研究模的r-比较性和r-幂比较性,给出了r-比较性的新刻划,得到了模的r-幂比较结构与其自同态环的r-幂比较性间的关系,证明了如果模M为r-幂比较的则它的任意直和项也是r-幂比较的．对于可分置换环,给出了r-幂比较性与r-比较性间的联系．     

玉米地膜与露地栽培主要性状的灰色关联分析

运用灰色系统理论的灰色关联分析方法,分别对西藏林芝地区玉米地膜与露地栽培主要性状与产量之间的关系进行了探讨.分析结果表明,两种种植方式都表现为果穗粒重对产量影响最大.在玉米地膜栽培条件下,果穗重、单株绿叶面积对其产量影响较大,株高、秃顶长对其产量影响较小;在玉米露天栽培条件下,百粒重、果穗重对其产量影响较大,秃顶长、单株绿叶面积对其产量影响较小.     

THE STABILITY AND APPROXIMATION PROPERTIES OF RITZ-VOLTERRA PROJECTION AND APPLICATIONS,Ⅱ

l introductionho Paper is the second part of our work on the Ritz-Volterra projection and its applicationS. In the ho Pot['7, we have aide a systematic study on the stability and approximationprO~ Of RitZ-Volterra theectioo in ac and L, spaces for 2igloo. In this paper, as acplications Of Ritz-Volterra projection, we wb investigate the sealliscrete finite element approtoations to initial-boUndary value problems Of varys evolution equations such as parabolicand hyperbolic integral-differe…     

关联分析方法在立法学中的应用

本文在法学中首次引入了关联分析方法 ,分析结论比较可靠 ,同时从定量上对《中华人民共和国刑法》的修订提供了科学依据 .     

我国铁路货物运输发展的灰色关联分析

运用灰色系统理论的灰色关联分析方法,对我国铁路货运的发展及其影响因素进行了系统分析,较详细地叙述了分析过程,并将其结果进行数据分析对比,分析过程表明,灰色关联分析的方法简便易行,结果可靠.     

高速列车的关键力学问题

在过去10 年时间, 中国和谐号系列高速列车经历了一系列速度上的飞跃. 在最初引进消化吸收基础上, 研制了新一代高速列车并大规模投入运营, 伴随这一过程的大量试验与工程实践, 大大促进了对高速铁路这样一个车- 线- 网- 气流强耦合的复杂大系统中的关键力学问题的深入理解和全面研究. 该文将从6 个方面对高速列车研制和运行过程中的典型力学问题的研究进展以及未来的研究方向做一个梳理. 考虑到这样一个大系统的复杂性,同时也为了使对高速列车感兴趣的技术与科研人员对这些力学问题有一个比较全面的认识, 文中将分别就高速列车的空气动力学、弓网关系、车体振动与车体模态设计、车体运行稳定性、高速轮轨关系、关键结构的运行可靠性和列车噪声等方面的研究进行总结和展望. 同时也对中国及国际高速列车发展趋势及其中的力学问题做了一个简要介绍.      

光电跟踪系统论证与设计

以配套于武器系统的光电跟踪系统为基础,论述了光电跟踪系统在论证与设计中应主要考虑的问题。从实际系统情况出发,讨论了光电跟踪系统的传感器选择原则和T型与U型架式配置优缺点。分析了确定作用距离、跟踪精度、响应速度、工作范围等核心指标的主要因数,确定了与核心指标相对应的光电跟踪系统内部的指标需相应考虑的因数,提出了导引截获、轴系关系等与系统关联的技术因数等。     

反相高效液相色谱法同时测定甘草酸单铵盐原料药主成分及有关物质含量

建立了同时测定甘草酸单铵盐原料药中主成分18α-甘草酸、18β-甘草酸及其有关物质A、有关物质B含量的高效液相色谱法,并用于其质量标准的建立。采用Durashell C₁₈色谱柱(250 mm×4.6 mm, 5 μm),以10 mmol/L高氯酸铵(氨水调节pH 8.20)-甲醇(48:52, v/v)为流动相,流速0.80 mL/min,检测波长254 nm,柱温50 ℃,进样量10 μL。在优化的色谱条件下,18α-甘草酸、18β-甘草酸、有关物质A、有关物质B在0.50~100 mg/L范围内线性关系良好(r>0.9999),检出限分别为0.15、0.10、0.10、0.15 mg/L,平均回收率在97.32%~99.33%之间(n=3),相对标准偏差(RSD)在0.05%~1.06%之间。本方法检测灵敏、重现性好,结果准确可靠,可用于甘草酸单铵盐原料药主成分及有关物质的检测分析,有利于其原料药的质量控制。     

Dynamics of atomic decay in a special one dimensional photonic crystal

Recently, Liu et al. [Phys. Rev. B 74, 075314 (2006)] pointed out that the atomic instant decay rate in one dimensional photonic crystal (1DPC) showed a series of pulse-like peaks with time. In this paper, we continue their work, and adopt a special 1DPC, in which the refractive indexes of both constitution layers in a period are the same, to perform the analysis in detail. Our results show that the pulse-like peak of instant decay rate originates from the interaction between the atom and the sub-reservoir, the latter of which corresponds to the group of reflected fields having the same optical distance. The atom interacts with such a sub-reservoir mainly after the time needed for propagation. However, near the arrival time of the reflected field, the atomic level is broadened and couples to all frequency components of the sub-reservoir, and the pulse-like peak of instant decay rate appears. Although our conclusion is deduced with the special 1DPC, it is also valid for more general cases and might be useful to measure the quantum Zeno and anti-Zeno effect, since the interval of repeated measurements may be expanded to several optical cycles in 1DPC, which will facilitate the observation of the quantum Zeno or anti-Zeno effect.