美丽文件带着走 电子文件网上飞──华康科技推出便携文件专家DynaDoc3.5

随着电子信息时代的来临，电子文件的传递交流在人们的日常工作中所占的位置越来越重要。但由于不同的平台、不同的语种、不同的应用软件等原因，给文件的交流造成了极大的困扰，例如显示乱码，显示、打印格式与原排版格式不同等。华康科技开发有限公司最近推出便携文件专...     

积分中值ξ=ξ(x)的渐近性

对一类不满足g(n)≠0的函数g讨论了第一积分中值定理中ξ=ξ(x)在x→+∞时的渐近性质,并对第二积分中值定理的中值ξ=ξ(x)的渐近性进行了探讨,给出一些相关的结果.     

光学材料热光系数的精确测量——“热光系数仪”

本文介绍用于光学材料系数精确测量的“热光系数仪”。该仪器采用两种干涉仪组合、微机控制和数据采集处理等设计方案,实现了高精度测量。低温区热膨胀系数α、折射率温度系数β热光系数W的测量精度可达±3×10~(-7)°C~(-1)。     

DX—400自动化控制系统简介

广播发射机实现自动化与智能化是今后发展趋势和技术要求，采用何种结构，实现哪些功能，本提供了一定参考价值。     

第十四讲 现代数字影视系统的条件接收技术

数字电影（Digital Cinema）、手持电视（手机电视）是现代影视技术的发展方向，它既和数字电视有着许多共同的地方，又具有各自的特殊之处。影视业发展的趋势一定着重在增值服务方面，因此条件接收是必须用到的技术。由于各自的特点，在数字电视系统中用到的条件接收技术能否直接用于现代影视系统中去，值得探讨。     

MULTIPLE EQUILIBRIA IN BAROCLINIC ATMOSPHERE BY THERMAL FORCING RELATED TO SUBTROPICAL HIGH

By using Lorenz's moist general circulation model, a nonlinear and dissipative system describing atmospheric motion has been obtained in approximation of Low Order.The multiple equilibria and the transformation between the flow patterns of winter and summer, the latitudinal oscillation of subtropical high by thermal forcing and nonlinear interaction of general circulation are studied in this paper.The results show that the transformation of flow patterns is a discontinuous leaping, and is a process of resetting new flow pattern by rapid exchange inflow field.In the corresponding dry model, we cannot find the latitudinal oscillation of the center of subtropical high.In the moist model, after the thermal effect of water vapor is drawn into the model, nonlinear interaction appears between flow and heating fields.This effect helps to bring about the latitudinal oscillation of subtropical high.     

基于物理学专业的电子技术课程教学模式研究

分析了目前物理学专业电子技术课程教学所面临的困难,提出了电子技术课程教学新模式。教学实践表明,教学新模式的应用,能激发学生自主学习的兴趣,促进学生掌握相关学科的基本知识、基本理论和基本技能,提高学生的团队合作能力、综合开发能力和创新能力。     

Growth of gem-grade nitrogen-doped diamond crystals heavily doped with the addition of Ba（N3）2

Additive Ba(N 3) 2 as a source of nitrogen is heavily doped into the graphite-Fe-based alloy system to grow nitrogendoped diamond crystals under a relatively high pressure (about 6.0 GPa) by employing the temperature gradient method.Gem-grade diamond crystal with a size of around 5 mm and a nitrogen concentration of about 1173 ppm is successfully synthesised for the first time under high pressure and high temperature in a China-type cubic anvil highpressure apparatus.The growth habit of diamond crystal under the environment with high degree of nitrogen doping is investigated.It is found that the morphologies of heavily nitrogen-doped diamond crystals are all of octahedral shape dominated by {111} facets.The effects of temperature and duration on nitrogen concentration and form are explored by infrared absorption spectra.The results indicate that nitrogen impurity is present in diamond predominantly in the dispersed form accompanied by aggregated form,and the aggregated nitrogen concentration in diamond increases with temperature and duration.In addition,it is indicated that nitrogen donors are more easily incorporated into growing crystals at higher temperature.Strains in nitrogen-doped diamond crystal are characterized by micro-Raman spectroscopy.Measurement results demonstrate that the undoped diamond crystals exhibit the compressive stress,whereas diamond crystals heavily doped with the addition of Ba(N 3) 2 display the tensile stress.     

利用Gupta势研究ConCu13-n (n=1～12)混合团簇的基态结构和熔化行为

利用Gupta多体相互作用势结合遗传算法和分子动力学方法模拟研究了ConCu13-n (n=0～13)单质及混合团簇的基态结构和熔化行为,结果表明：ConCu13-n (n=1~12)混合团簇的基态结构均是在单质Co13、Cu13基态二十面体基础之上的畸变,Co原子先占据中心后占据表面,表面上的Co原子总连接在一起,抱团分布;分析二级差分能和混合能发现Co1Cu12、Co7Cu6具有相对高的稳定性,可视为幻数结构团簇;ConCu13-n (n=1~12)混合团簇的熔点均位于Co13、Cu13单质团簇的熔点之间,且随着Co原子数目的增多总体呈上升趋势,但在n=3时出现反常（熔点降低）,这可归因于Co3Cu10的基态与第一激发态之间的能量差远小于Co2Cu11的相应值。