一类集值映像方程的若干问题的研究

首先研究了多值严格集压缩场的不动点指数计算的一些结果，并且利用了映像的拟微分性结合边界条件（Sw,A,u)及（Lw,u)研究多值映像方程的正解，多正解与固有元等问题。     

慢性阻塞性肺疾病采用CT诊断效果分析

目的:探讨CT诊断慢性阻塞性肺疾病的效果方法.选取我院2008年1月至2009年12月46例慢性阻塞性肺疾病患者,将其X线与CT两种诊断的结果进行对比分析.结果:X线与CT两种方法诊断慢性阻塞性肺疾病具有较高的确诊率,实际结果差异性不大.结论:CT技术诊断慢性阻塞性肺疾病有较高的医学价值,值得临床应用.     

转子系统碰摩行为的研究

应用非线性动力学现代理论对一个带间隙转子系统的数学模型进行了研究 ,通过以转速比变化为参数的分岔图发现 :在超临界转速下存在完整的间隔混沌、周期加分岔序列 ,即系统在周期运动与混沌运动之间交替 ,且周期加一、周期数与临界转速的倍数对应相等 ;在转速小于临界转速时 ,各个连续阶次谐运动的转换区分别都出现了经由一个倍周期分岔直接导致的混沌频带 ,后又直接由一个逆倍周期分岔转化为周期一的现象。同时还揭示了阻尼对系统谐波振动幅值和转换区混沌频带宽的抑制作用 ,以及非线性刚度对混沌频带的抑制和对谐波响应幅值的促进作用。提出设计转子系统时应适当增加阻尼和选材时综合考虑系统的动力学特性 ,系统提高转速时 ,转速不要在转换区滞留太长及工作转速尽量不要选在系统的临界转速的倍频上等建议 ,这些都对减小系统故障发生率和提高系统动力学特性有重要意义     

间隙约束悬臂梁振动系统动力行为研究

运用分段线性系统分析理论，研究间隙约束的悬臂梁振动系统在简谐激励下系统稳态响应的动力学行为。首先建立间隙约束的一般线性系统动态响应分析的理论模型，以传递函数为基础，推导系统的动力学分析方程及其求解方法。然后对系统进行数值求解分析，得到该系统稳态响应随激励频率、幅值以及间隙接触刚度和阻尼变化的一般规律。研究结果对于间隙振动系统分析和间隙型减振结构设计都有重要意义。     

Sorption Power of the New Generation of Phytosorbents with Respect to Uranium

The sorption power of a new class of sorbents, phytosorbents, with respect to uranium was studied in model solution and real waters. Sorption was studied as influenced by the specific mass of the sorbent. The kinetic parameters of the sorption were determined, and diffusion inside the sorbent grain was identified as the limiting stage of the process. The diffusion coefficients were calculated; the exchange half-times were determined and confirmed. The uranium sorption was studied as influenced by pH. The maximal sorption of uranium is achieved at pH <4. The exchange capacities of the sorbents were determined.     

金属铀表面经CO处理后的抗蚀性研究

采用增重法和电化学方法分别研究了金属铀表面经CO处理后的抗热氧化腐蚀能力和抗化学介质腐蚀的能力。结果表明：金属铀表面经CO处理后的抗氧化能力有所提高,抛物线氧化阶段其氧化速率比未处理样品的氧化速率低25％－60％;电化学研究表明;金属铀表面经CO处理后,其抗化学介质腐蚀的能力增强;在实验所用CO剂量范围内,其抗蚀性随CO剂量的增加而增强。     

Studies on the Chemistry of Uranium and Thorium Phosphates. Thorium Phosphate Diphosphate: A Matrix for Storage of Radioactive Wastes

Studies on phosphates of tetravalent uranium and thorium published by the authors in the 1990s are briefly overviewed. Methods of synthesis, properties, and structures of new phosphates of these elements are described. The chemical formulas of a number of already known uranium, thorium, and neptunium phosphates are critically analyzed. Special attention is given to thorium phosphate diphospate and solid solutions containing uranium, neptunium, and plutonium. These are suggested as ceramics for storage of radioactive wastes of actinides. The suitability of thorium phosphate diphosphate for immobilization of nuclear fission products is discussed.     

Uranium dose assessment: a Bayesian approach to the problem of dietary background

Workers are routinely monitored by urinalysis for exposure to uranium at Los Alamos National Laboratory. Urine samples are analysed by alpha spectroscopy for 234U, 235U and 238U. Interpretation of the data is complicated by the presence of natural uranium in the workers' drinking water and diet. Earlier methods used drinking water samples to estimate the dietary component in urine excretion. However, there proved to be insufficient correlation between drinking water concentration and excretion rate. Instead, an iterative calculation is used to identify a typical excretion rate for each individual in the absence of occupational intakes. Bayesian dose-assessment methods, first developed for plutonium bioassay at Los Alamos, have been adapted for uranium. These methods, coupled with an algorithm for identifying each individual's baseline level of uranium from environmental sources, yield improved reliability in the identification of occupational intakes.     

考虑人员能力差异的装配生产线优化

针对具有人员能力差异的装配生产线节拍优化问题,建立数学模型,提出一种先分配工序、后分配工人的分步求解启发式方法,并分别利用双种群遗传算法和分枝定界法对其进行求解;提出构建原优化问题的上下界,并以某企业的装配生产线为实例,验证了本方法的有效性与实用性。     

具有三次曲线解的Kolmogorov三次系统的极限环

本文研究一类具有过原点的三次曲线解的Kolmogorov三次系统。首次给出并证明了一种简化的等价系统,得到了此系统既不位于坐标轴也不位于三次曲线解上的奇点的精确表达式。证明了在一定条件下存在极限环,而且至少存在三个极限环,并给出了数值例子。     

Bounds to Shakedown Loads for a Class of Deviatoric Plasticity Models

The problem of estimating bounds to shakedown loads for problems governed by a class of deviatoric plasticity models including those of Hill, von Mises, and Tresca is addressed. Assuming that an exact elastic solution is available, an upper bound to the elastic shakedown multiplier can be obtained relatively easily using the plastic shakedown theorem. A procedure for computing this upper bound for arbitrary load domains is presented. A number of problems are then examined and it is found that the elastic shakedown factor is given as the minimum of the plastic shakedown factor and the classical limit load factor. Finally, some exact solutions to a number of two dimensional problems are given.     

Exposure of the flux of a medium to a regular system of light sources

An analysis is performed of the stationary distribution of the specific dosage of radiation energy absorbed by a medium from a regular system of tubular light sources submerged in an infinite flux of the medium.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 48, No. 3, pp. 437–442, March, 1985.     

截尾数据下一类半参数回归模型的估计

讨论了一类半参数回归模型y =x′β+g(t′α) +e .假定y被随机变量T右侧截尾 ,T与y独立 ,T～G。在G已知和未知两种情况下 ,构造了α、β和g(·) 的强相合估计     

一类具有抛物线解的三次系统的定性研究

本文给出了一类具有代数曲线解的三次系统的全局结构及相应的系数条件。     

Studies on textural properties of lanthanum-exchanged Y zeolites as promising materials for value upgradation of Jatropha oil

A series of La (Lanthanum)-exchanged Y zeolites have been prepared and the changes occurred in textural properties of the material have been characterized by XRD, SEM, surface area, pore volume, and pore size distribution techniques. La loading was observed to enhance not only acidity but also the porosity (in terms of mesopores) of the Y zeolite. The parent HY and three La loaded samples (LaHY-1, LaHY-2, and LaHY-3) have been studied for the changes in properties occurred by La loading and their collective influence on the catalytic performance toward the Jatropha oil to gasoline (JTG) reaction. All the catalysts exhibited 100 % conversion but the performance toward the gasoline selectivity is increased in the order of HY < LaHY-3 < LaHY-1 < LaHY-2. Detailed analysis of the results indicated that the increase in porosity (both in micro- and meso-pore region) rather than the acidity is responsible for enhanced catalytic performance of the LaHY-2 catalyst. This particular catalyst also exhibited lower coke formation and prolonged time-on-stream stability in the JTG reaction ascribed to the facile diffusion of the product molecules facilitated in mesopores.     

一类线性中立型摄动系统基于LMI方法的反馈镇定

考虑了一类滞后量未知的状态及控制输入均有摄动的中立型系统的镇定问题。基于设计无记忆状态反馈控制器,利用Lyapunov稳定性理论,在给出无摄动系统的LMI镇定条件的基础上,得到了具有结构摄动中立型系统的二次镇定性条件。并举例说明结果的有效性。     

具有一类三次曲线解的二次系统极限环的存在性问题

具有非轴对称三次曲线解的二次系统可以存在非代数极限环。     

成员文化异同对群体绩效影响的国外研究综述

国外有很多关于成员文化异同对群体绩效影响的研究，国内却极少。国外研究发现，群体成员文化的差异和相似对群体绩效的影响都不是绝对的，有时它们能增强群体绩效，有时它们却降低群体绩效，而且它们的影响会随时间推移而变化。随着我国改革开放的不断深化，努力开展中国本土化的相关研究必要而紧迫，具体可分“克隆”国外相关研究和重新设计实验进行研究两步。     

一类矩阵方程组带有子矩阵约束的最小二乘中心对称解

约束矩阵方程问题在控制理论、振动理论、工程和科学计算等领域具有重要应用.基于共轭梯度法的思想,本文构造了一种算法,以寻求一类矩阵方程组的带有子矩阵约束的最小二乘中心对称解.在没有舍入误差的情况下,该算法经过有限步迭代得到了矩阵方程组带子矩阵约束的最小二乘中心对称解,而且,通过选择一种特殊的初始矩阵,得到了矩阵方程组的带子矩阵约束的最小范数最小二乘中心对称解.数值实验显示该算法具有较快的收敛速度.