ASYMPTOTIC BEHAVIOR OF THE DRIFT-DIFFUSION SEMICONDUCTOR EQUATIONS

This paper is devoted to the long time behavior for the Drift-diffusion semi-conductor equations. It is proved that the dynamical system has a compact, connected and maximal attractor when the mobilities are constants and generation-recombination term is the Auger model; as well as the semigroup S(t) defined by the solutions map is differential. Moreover the upper bound of Hausdorff dimension for the attractor is given.     

P(α,α′)πN反应中N(1440)激发的蒙特卡罗研究

在P(α,α′)πN反应的几种反应机制中研究N^*(1440)激发, 利用蒙特卡罗模拟的办法重现N^*(1440)共振峰的位置, 我们在给定入射能量情况下模拟出末态各出射粒子的动量, 角分布情况. 计算结果可以在πN的不变质量谱中观察到明显的N^*(1440)共振峰, 同时达里兹图中在πN系统能量平方为2100MeV²附近事件分布密集, 而别的组态却没有观察到这些情况, 这都说明了πN共振粒子N^*(1440)的产生.     

Big Bounce Singularity of a Simple Five—Dimensional Cosmological Model

The big bounce singularity of a simple five-dimensional cosmological model is studied.Contrary to the standard big bang space-time singularity,this big bounce singularity is found to be an event horizon at which the scale factor and the mass density of the universe are finite,while the pressure undergoes a sudden transition from negative infinity to positive infinity.By using coordinate transformation it is also shown that before the bounce the universe contracts deflationary.According to the proper-time,the universe may have existed for an infinitely long time.     

利用面板数据模型分析湖南城镇居民的收入与消费之间的关系

本文利用面板数据模型研究湖南省城镇居民1999-2005年收入与消费之间的关系,分析湖南居民的收入差异对居民消费的影响,为今后调整湖南的消费结构,扩大内需,促进经济发展提供理论依据.     

高能核碰撞中带电多重数快度与能量和中心度的关系

用强子–弦级联模型JPCIAE及相应的Monte Carlo事例产生器研究相对论性核–核碰撞中带电粒子多重数的赝快度密度对能量和中心度的依赖关系.无需另调任何模型参数的条件下,此模型可以同时较好地描述相对论性pp实验数据及PHOBOS和PHENIX实验组的Au+Au实验数据.本文指出:因〈N_part〉并非严格定义的物理量,致使实验上和理论上确定〈N_part〉有一定任意性,从而使得每参加者核子对的带电粒子赝快度密度随着〈N_part〉的增加可能逐渐增大,也可能逐渐减小,因此用它来区分粒子产生机制是欠妥的.     

Critical Behaviour of the One—Dimensional Ferromagnetic t—J Model

The one-dimensional super-symmetric ferromagnetic t-J model is studied via the thermal Bethe ansatz.Analytic expressions of the free energy for T→O are obtained.A new critical behaviour beyond the universal class of Luttinger Liquids is found in this system.     

Instability of Longitudinal Wave in Magnetized Strongly Coupled Dusty Plasma

Instability of longitudinal wave in magnetized strongly coupled dusty plasmas is investigated. The dust chargigrelaxation is taken into account. It is found that there exists threshold of interdust distance for the instability of wave, which is determined significantly by the dust charging relaxation, the coupling parameter of high correlation of dust as well the strength of magnetic field.     

带息力更新风险模型的一个极值分布

本文讨论了带息力的更新风险模型,得到了破产前最大盈余分布的递推公式,且在此基础上还给出了它满足的积分方程.     

基于目标信息系统学习的多准则决策方法

给出目标信息系统学习的多准则决策方法，建立多准则决策的规则学习模型，讨论该模型的性质。该模型优于Z．Pawlak方法，将规则提取与信息融合为一体。也优于AHP等模型，具有简洁性．通过实例计算，取得了满意结果。     

15C的中子晕结构研究

实验测量了83A MeV ^14,15C的核反应总截面(σ_R)及¹⁵C产生^14,15C和¹⁴C产生¹³C的动量分布(P_//). 分析得到了¹⁵C产生¹⁴C和¹³C的动量分布半高宽(FWHM)分别为71±9MeV/c和223±28MeV/c, 而¹⁴C产生¹³C的FWHM为195±21MeV/c. 从¹⁵C和¹⁴C产生¹³C的FWHM与Goldhaber模型的预言基本一致. 而¹⁵C产生¹⁴C的FWHM却要比该模型计算小得多. 同时观测到¹⁵C的σ_R比相邻核有反常增加. 在Glauber模型框架中, 对实验测得的P_//和σ_R进行了探讨. P_//和σ_R的分析结果同时显示¹⁵C的最后一个中主要处于s_1/2态, 具有中子晕结构.