一类非线性多时滞脉冲抛物型方程解的振动性质

本文研究一类非线性多时滞脉冲抛物型方程在齐次Dirichlet和Neumann边界条件下解的振动性质.利用分析技巧,给出一个脉冲微分不等式无最终正解(或最终负解)的条件.然后,利用平均法,将该方程解振动性问题转化为相应脉冲时滞微分不等式有无最终正解(或最终负解)问题,进而在两类齐次边界条件下获得了判别该类方程解振动的充...     

具分段常数变元的脉冲微分不等式与脉冲积分不等式

本文研究了一类具分段常数变元的脉冲微分不等式.利用归纳和迭代法,得到了这类不等式解的有效估计.通过选择适当的变换,文中得到了若干具分段常数变元的脉冲积分不等式解的有效估计.最后,给出了该类不等式在脉冲微分系统振动性方面的应用.     

具拟线性扩散系数的脉冲中立型抛物系统的(强)振动性

研究一类具拟线性扩散系数的脉冲中立型抛物偏微分系统解的(强)振动性, 直接利用振动的定义、Green公式和Newmann边值条件将这类脉冲中立型抛物系统的振动问题转化为脉冲中立型微分不等式不存在最终正解的问题, 并利用最终正解的定义和脉冲中立型微分不等式, 获得了该类系统(强)振动的充分判据. 所得结果充分反映了脉冲和时滞在振动中的影响作用.     

具高阶Laplace算子的非线性脉冲中立抛物型方程的振动性

本文研究一类具高阶Laplace算子的非线性脉冲中立型时滞抛物偏微分方程的振动性质,利用一阶脉冲时滞微分不等式,获得了该类方程在两类不同边值条件下所有解振动的若干充分性判据.所得结论将脉冲时滞微分方程的振动性质推广到脉冲中立型时滞偏微分方程,同时也反映了脉冲和时滞在振动中的影响作用.     

一类非线性脉冲中立型时滞抛物方程组的振动准则

本文研究一类非线性脉冲中立型时滞抛物方程组的振动性,利用一阶脉冲中立型微分不等式,获得了该类方程组在两类不同边界条件下所有解振动的若干充分条件。所得结果充分反映了脉冲和时滞在振动中的影响作用。     

一类非线性时滞双曲型偏微分方程的振动性

研究一类非线性时滞双曲型偏泛函微分方程解的振动性，利用微分不等式方法和广义Riccati变换，获得了该类方程在第一类边值条件下振动的新的充分条件，所得结果通过实例加以阐明．     

二阶脉冲中立型时滞微分方程解的渐近性

本文研究一类二阶脉冲中立型时滞微分方程解的渐近性质.利用一个重要的脉冲微分不等式和一些不等式技巧,并利用经典Riccati变换,获得了该方程所有解趋于零的充分条件,从而改进并推广了现有文献的主要结果.通过两个实例,说明所得定理在应用中的有效性.     

具连续分布滞量的非线性抛物型偏微分方程的振动准则

考虑一类具连续分布滞量的非线性抛物型偏微分方程的振动性，借助Green定理将多维振动问题转化为关于某一类具连续分布滞量的非线性微分不等式的一维问题，给出了该类方程在Robin，Dirichlet边值条件下所有解振动的若干充分判据。所得结论充分地表明，振动是由时滞量引起的。     

一类含时间分数阶导数的膜振动方程近似解析解的研究

研究一类含时间分数阶导数的膜振动方程,该方程边界正弦摄动变化。先对边界自变量应用泰勒级数展开,引入多重尺度到原方程及边界,利用Riemann-Liouville分数阶导数定义和性质得到关于小参数的零阶近似解。应用微分不等式理论证明了解的一致有效性。利用图形分析出各参数对解的影响。     

具连续分布滞量的高阶非线性偏泛函微分方程的强迫振动性

研究一类具连续分布滞量的高阶非线性偏泛函微分方程,利用微分不等式方法,给出了这类方程在三类边值条件下解的强迫振动的充分条件,所得结果推广和包含了已知的一些结论。     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Assessment of intakes of mixtures of radionuclides

Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides.     

Analysis of anisotropy of properties on the basis of studies of texture of coarse-grained ingots of thermoelectric materials

An analysis of anisotropy of the properties of a Bi₂Se_0.3Te_2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

卧式金属罐容量的测量结果不确定度

本文根据多年的实践检定经验 ,参照JJF1 0 59- 1 999《测量不确定度评定与表示》以及《测量不确定度表达 1 0讲》 ,对卧式金属罐容量的测量结果不确定度进行了评定。     

盐酸浓度不确定度的评估

通过对盐酸浓度标定的过程分析，找出影响结果的各个分量，进行不确定度的评定，按照计量技术规范给出标准的表示法。