变系数线性微分方程的算子解法

首先讨论变系数线性微分算子因式分解式的存在条件 ,并且给出微分算子因式分解的一些技巧 ,然后给出变系数线性微分方程算子解法的两种方法 .     

回归分析在殷墟墓葬分期中的应用

数理统计方法，在我国考古学中的应用，目前处于探索、研究阶段。本文试用回归方法，建立殷墟墓葬分期的多元线性回归模型，并确定出墓葬分期的预测区间。     

Nordsieck representation of DIMSIMs

A new representation for diagonally implicit multistage integration methods (DIMSIMs) is derived in which the vector of external stages directly approximates the Nordsieck vector. The methods in this formulation are zero-stable for any choice of variable mesh. They are also easy to implement since changing step-size corresponds to a simple rescaling of the vector of external approximations. The paper contains an analysis of local truncation error and of error accumulation in a variable step-size situation. This revised version was published online in June 2006 with corrections to the Cover Date.     

Measurement of fast neutron induced fission cross section of thorium using Lexan plastic track detector

Fission-track registration characteristics of Lexan solid state nuclear track detectors have been used to measure the fast neutron induced fission cross section of²³²Th. The fast neutrons (?14.2MeV) were produced with the help of an AN-400 model Van-de-Graaff accelerator at Banaras Hindu University laboratory using³H(²H,n)⁴He reaction and were used to irradiate the fissile target deposited on the plastic detector. The track densityT, registered on the plastic detector is related to the fission cross sectionσ _f, through the relationT=knσ _føt wheren is the number of fissile atoms per cm² in the deposit, ø is the neutron flux,k is fission track registration efficiency andt is the time of irradiation. The fission cross sectionσ _f of²³²Th, relative to the well measured fission cross section of²³⁸U, was found to be 0.36±0.04 barn.     

Oscillation criteria for a class of neutral difference equations with continuous variable

In this paper, we are mainly concerned with oscillatory behaviour of solutions for a class of second order nonlinear neutral difference equations with continuous variable. Using an integral transformation, the Riccati transformation and iteration, some oscillation criteria are obtained.     

核子碰撞截面的介质修正对多重碎裂的影响

利用同位旋相关的量子分子动力学模型研究了中能重离子碰撞过程中,同位旋相关的核子碰撞截面的介质修正对于多重碎裂的影响.结果表明:在包括动量相关作用在内的软势的情况下,介质修正明显地提高了自由核子的发射和中等质量碎片的多重性对于核子碰撞截面的同位旋依赖的敏感性.但对于原子核阻止敏感地依赖于核子碰撞截面的同位旋效应而不敏感地依赖于对称势的形式这一性质的影响并不明显,因此,原子核阻止对于核子碰撞截面的同位旋依赖的敏感性主要决定于自由核子碰撞截面的同位旋相关性.     

State-dependent weights in multicriteria value functions

In this paper, the concept of state-dependent weights is studied. This offers the flexibility to approximate the changing weights of the decision maker. The relationship between state-dependent weights and value functions is discussed.     

THE EQUATION OF MOTION FOR THE SYSTEM OF THE VARIABLE MASS IN THE NON－LINEAR NON－HOLONOMIC SPACE

ＴＨＥＥＱＵＡＴＩＯＮＯＦＭＯＴＩＯＮＦＯＲＴＨＥＳＹＳＴＥＭＯＦＴＨＥＶＡＲＩＡＢＬＥ　ＡＳＳＩＮＴＨＥＮＯＮ－ＬＩＮＥＡＲＮＯＮ－ＨＯＬＯＮＯＭＩＣＳＰＡＣＥＴＨＥＥＱＵＡＴＩＯＮＯＦＭＯＴＩＯＮＦＯＲＴＨＥＳＹＳＴＥＭＯＦＴＨＥＶＡＲＩＡＢＬＥ...     

变量聚类—全局主成分分析在我国普通高等教育发展水平评价中的应用

本文根据1997年~2003年共同构成的关于我国普通高等教育发展水平的时序立体数据表,对各地区高等教育发展整体状况的各项指标进行变量聚类,以区分对我国高教发展背景与现状分别产生影响的各项指标,然后对每一类作主成分分析,选出能够代表该类的主成分。在此基础上,计算出各地区各年度主成分的增长度;再对各年度主成分的增长度作主成分分析,以期对我国高教发展背景与现状的总体变化趋势做出综合评价。     

非自治中立型时滞差分方程的振动性

研究具有可变时滞的非自治中立型差分方程Δ(xn-cxn-k)+h(n,xn-ln)=0,n=0,1,2,…的振动性,得到了这类差分方程振动的必要条件、充分条件和充要条件,同时得到了这类方程的最终正解存在性判据.