Intermediate Self-similar Solutions of the Nonlinear Schrodinger Equation with an Arbitrary Longitudinal Gain Profile

We study pulse propagation in a normal-dispersion optical fibre amplifier with an arbitrary longitudinal gain profile by self-similarity techniques. We show the functional form of the development of low-amplitude wings on the parabolic pulse, which are associated with the evolution of an arbitrary input pulse to the asymptotic parabolic pulse solution. It is found that for the increasing gain the amplifier output corresponding to the input Gaussian pulse converges to the asymptotic parabolic pulse solution more quickly than the output obtained with the input hyperbolic secant pulse, whereas for the decreasing gain the input pulse profiles have nearly no effect on the speed of convergence to the parabolic pulse solution. These theoretical results are confirmed by numerical simulations.     

Carriers recombination processes in charge trapping memory cell by simulation

We have evaluated the effects of recombination processes in a charge storage layer, either between trapped electrons and trapped holes or between trapped carriers and free carriers, on charge trapping memory cell＇s performances by numerical simulation. Recombination is an indispensable mechanism in charge trapping memory. It helps charge convert process between negative and positive charges in the charge storage layer during charge trapping memory programming/erasing operation. It can affect the speed of programming and erasing operations.     

发光二极管电视、符号显示

国内外对发光二极管单片式、混合式矩阵显示装置正在进行活跃的研究。成为这种二极管显示装置的基本技术有:制备高效率p-n结;在单一晶体基板上制作多个发光元件的集成化技术;把多个发光二极管组装起来的电气联结技术以及最佳的取光结构等。 近年来,由于GaAsP、GaP发光二极管的效率显著提高;集成化技术、组装技术的进展以及结构上的巧妙设计;用发光二极管显示装置部分地取代阴极射线管显示的可能性日趋增大起来。 本文研究了发光二极管平面显示装置的电视图像显示及文字、数字——符号显示的特性;并论述了作者最近试制的GaP绿色发光二极管平面显示装置的结构、特性及在电视显示、符号显示上的应用。     

改进考試方法,发揮学生在学习上的主动性

(一) 怎样引起改进的我们是根据考试的目的来改进考试方法的。对考试目的的认识,我们是有一个过程的。过去,把考试当作推动学生学习的法宝,认为学生学不好,就要考,把它当成强迫学生学习的一种手段,同时,把考试作为检查学生学习质量的唯一手段,认为考试越突然,就越能看出学生的真正水平。基于这些错误认识,伴随而来的就是考试多,采取突然袭击,其结果造成学生过分紧张与畏惧的情绪,造成精神上的沉重负担,学     

Isoscaling in Statistical Sequential Decay Model

A sequential decay model is used to study isoscaling, i.e. the factorization of the isotope ratios from sources of different isospins and sizes over a broad range of excitation energies, into fugacity terms of proton and neutron number, R21（N, Z） = Y2（ N, Z）/Y1（ N, Z） = Cexp（αN -βZ）. It is found that the isoscaling parameters α and β have a strong dependence on the isospin difference of equilibrated source and excitation energy, no significant influence of the source size on α andβ has been observed. It is found that α and β decrease with the excitation energy and are linear functions of 1/T and △（Z/A）2 or△（N/A）2 of the sources. Symmetry energy coefticient Gsym is constrained from the relationship of a and source △（Z/A）2, /3 and source △（N/A）2.     

Nuclear Potential and Fusion Cross Sections for Synthesizing Super-Heavy Elements in Di-nuclear Systems

A double foMing method with simplified Skyrme-type nucleon nucleon interaction is used to calculate the nuclear interaction potential between two nuclei. The calculation is performed in tip-to-tip orientation of the two nuclei if they are deformed. Based on this method, the potential energy surfaces~ the fusion probabilities and the evaporation residue cross sections for some cold fusion reactions leading to super-heavy elements within di-nuclear system model are evaluated. It is indicated that after the improvement, the exponential decreasing systematics of the fusion probability with increasing charge number of projectile on the Pb based target become better and the evaporation residue cross sections are in better agreement with the experimental data.     

超薄LiTaO3晶片的键合减薄技术

在制造红外热释电探测器阵列过程中，需要利用超薄钽酸锂(LiTaO₃)晶片作为红外热释电探测器件的敏感层。通常LiTaO₃晶片的厚度远厚于红外热释电探测器件要求的厚度，所以需要采用键合减薄技术对LiTaO₃晶片进行加工处理。键合减薄技术主要包括：苯并环丁烯（BCB）键合、铣磨、抛光、加热剥离、刻蚀BCB。加工后得到面积为10mm×10mm、厚度为25μm的超薄单晶LiTaO₃薄膜，晶片厚度、表面粗糙度和面形精度比较理想。测得了LT晶片减薄后的热释电系数为1.6×10^-4Cm^-2K^-1。得到的单晶LiTaO₃薄膜满足红外热释电探测器敏感层的要求。     

N-亚硝基化合物导致DNA股间交联的HPLC-ESI-MS/MS分析

N-亚硝基化合物(NNCs)是一种重要的环境致癌物,它们能够导致DNA股间交联从而诱发癌症.研究表明NNCs经过代谢活化或分解后,最终以乙撑的形式导致DNA互补碱基对成对负性原子之间的共价交联.     

浅谈珠脑速算的发展前景

珠脑速算教育是启迪智力，进行素质教育，功在当代，利在千秋的“重要工程”它具有早期开发儿童智力，增强儿童感知力、想象力、记忆力等功能，那么这项科研项目，它的发展前景如何?成为从事这项科研的工作者和教育者普遍关注的问题。     

强流相对论性电子束在低压中性气体中传输的研究

本文给出了强流相对论性电子束(IREB)在低压中性气体中传输特性的理论和实验研究结果。660kV,40kA,脉宽100ns的电子束注入充有H_2,N_2的漂移管,稳定的传输气压范围在(0.7-6.7)×10~2Pa间,传输效率可达80％以上;极低气压时(P≈13.3Pa)由于空间电荷效应,束电子被虚阴极阻滞并径向发散,不能有效传输;而较高气压时,束电子除受自身电磁场作用及库仑碰撞散射外,等离子体不稳定性使束流传输效率明显降低。用蒙特·卡洛法及数值解析法对电荷中和、电流中和过程进行了模拟计算并解释了实验结果。