SIMULATION OF OCCUPATION FUNCTION FOR THERMALLY STIMULATED CONDUCTIVITY IN AMORPHOUS SEMICONDUCTORS

The occupation functions for the general condition f(E,T), for the high field approx-imation (HTSC) f_H(E,T) and for the steady state photoconductivity (SSPC) f_P(E,T) in the thermally stimulated conductivity (TSC) of amorphous semiconductors have been inves-tigated. It was found that the occupation function f(E,T) in TSC is in excellent agreement with the occupation function in SSPC f_P(E,T) under the condition of σ_TSC(T) = σ_P(T).There is a large difference between f_P(E,T) and f_H(E,T), which can be much reduced by introducing an effective attempt to escape frequency ν_eff in the calculation of f_H (E, T). The results show that the mobility-lifetime product (μτ) in TSC obtained from SSPC measure-ments under the above condition is valid. For high field approximation TSC, the simulated ν_eff is found to be temperature dependent.     

XRF测定铅锌矿选矿流程中铅,锌,铜

本文叙述一个ＸＲＦ粉末法测定铅锌矿选矿流程中铅，锌，铜的方法，选用精，中矿和原，尾矿两个标准系列。ＲｈＫａ康普顿散射线作内标克服质量吸收系数变化带来的影响，用经验系数法校正基体效应，与化学分析方法相比，本法县有测定组分含量范围广，简便，快速，准确和成本低等特点，配合选矿试验大大加快造矿周期，提高工效数倍。     

亚硝基甲胺异构化的量子化学研究

此文用ＭＮＤＯ方法研究了亚硝基甲胺异构化反应的机理。     

Cd3Al2Ge3O12:Mn2+锗酸盐石榴石光谱性质

本文报道室温下Cd₃Al₂Ge₃O₁₂:Mn²⁺(简称CAGG:Mn²⁺)锗酸盐石榴石的漫反射光谱、激发和发射光谱.在UV光激发下,在CAGG中Mn²⁺离子发射强黄光,这是基质到Mn²⁺离子无辐射能量传递的结果.Mn²⁺的黄发射带是由一个弱的红带和一个强的绿带所组成.讨论了这两个Mn²⁺发射带的起因.     

线阵扫描超声相关合成成像方法与实验

本文讨论了改进的医用B超线阵扫描探头在工业无损检测中的应用．在合成孔径聚焦技术（SAFT）基础上提出了改进方法，在探元响应带宽较窄的情况下可获得较高信噪比的成像结果．文中介绍了成像系统，实验方法，并给出了一些实验结果．     

里德伯钠原子经绝热快速通道的布居数跃迁相干控制

运用含时多态展开方法和B-样条函数研究了啁啾频率微波场中里德伯钠原子的量子态之间的布居数迁移.计算了里德伯钠原子n=70-77的开普勒频率.计算了在不同的微波场中六个态的布居数从n=70到n=77随时间的迁移,布居数跃迁到最终态n=77达到了98%,这可以通过连续的单光子跃迁来实现.结果表明,通过优化微波脉冲参数可以实现从低态到较高态的布居跃迁的相干控制.     

COF-42:一种理想的锂硫电池锚定材料

寻找理想的锚定材料抑制穿梭效应是锂硫电池面临的重要问题之一.本文采用密度泛函方法,研究了四种共价有机框架COFs材料(COF-1,CTF-1,COF-LZU1和COF-42)和硫锂化合物(Li_2S_n)的作用机理.通过分析吸附构型、吸附能、电子密度差分以及态密度等性质,发现COFs材料与硫锂化合物的化学吸附作用主要源于COFs表面极性N和O原子与Li之间的静电作用力.在COF-42/Li_2S_n吸附构型中,N和O原子与Li之间形成双重类离子键;电子密度差分和Bader电荷差分表明,与其他COFs材料相比,Li_2S_n和COF-42之间电荷转量最多,因此,COF-42具有最强的锚定作用.比较Li_2S_n和COF-42以及常用电解质分子1,3-二氧戊环(DOL)和二甲氧基乙烷(DME)的吸附能,证明COF-42可以抑制电解质分子的溶剂化作用; COF-42与COF-1,CTF-1和COF-LZU1相比较,具有良好导电性.因此,COF-42可能是一种理想的锂硫电池锚定材料.     

气液界面微观结构研究的一种实验新方法

许多物理、化学和生物过程发生于气液界面,且受到局域微观结构的深远影响. 不同于液体的体相,分子取向是界面处微观结构突出的不对称特征之一. 本文综述了电子碰撞时间延迟质谱方法和近期取得的进展. 利用这个崭新的方法,不仅可以侦测得到利用小角度X射线或中子散射以及振动和频光谱方法获得的界面微观结构,同时也提供了一种研究气液界面处电子驱动化学反应的实验方案.     

Stationary Distributions of GI/M/c Queue with PH Type Vacations

We study a GI/M/c type queueing system with vacations in which all servers take vacations together when the system becomes empty. These servers keep taking synchronous vacations until they find waiting customers in the system at a vacation completion instant.The vacation time is a phase-type (PH) distributed random variable. Using embedded Markov chain modeling and the matrix geometric solution methods, we obtain explicit expressions for the stationary probability distributions of the queue length at arrivals and the waiting time. To compare the vacation model with the classical GI/M/c queue without vacations, we prove conditional stochastic decomposition properties for the queue length and the waiting time when all servers are busy. Our model is a generalization of several previous studies.     

Analysis of Queueing Systems with Synchronous Single Vacation for Some Servers

We study a multi-server M/M/c type queue with a single vacation policy for some idle servers. In this queueing system, if at a service completion instant, any d (d c) servers become idle, these d servers will take one and only one vacation together. During the vacation of d servers, the other c–d servers do not take vacation even if they are idle. Using a quasi-birth-and-death process and the matrix analytic method, we obtain the stationary distribution of the system. Conditional stochastic decomposition properties have been established for the waiting time and the queue length given that all servers are busy.