808nm半导体激光器腔面硫钝化工艺研究

对808 nm大功率半导体激光器腔面硫钝化处理的工艺进行了研究,发现腔面硫钝化可以提高激光器的输出特性以及其可靠性,输出功率提高了16.7%;经过1 500 h老化实验后,硫钝化的半导体激光器没有明显退化,而未处理的激光器退化严重,输出功率降低了36.8%。实验表明,硫钝化时间对激光器钝化效果有很大影响,激光器腔面硫钝化时间过长会造成其损伤,使其可靠性反而下降;硫钝化5 m in效果为最佳。     

基于VisualC#.NET的动态网页设计与实现

介绍了基于VisualC#.NET的动态网页制作,ASP.NET的特性,框架集及TreeView Web控件的使用方法,以VisualC#.NET为项目开发平台,用Access建立后台数据库;以C#为程序设计语言,建立ASP.NET Web应用程序,实现精品课程网站的成绩查询、学生讨论区功能。     

STUDIES ON DIRECTLY REDIFFERENTIATING FLORAL BUDS BY EXPLANTS OF Hyacinthus orientalis L.——CONTROL OF MORPHOGENESIS OF FLORAL AND VEGETATIVE BUDS

The present work mainly deals with the control of redifferentiating of floral and vegetative buds by means of exogenous hormones and explants. The following results have been obtained: (ⅰ) When using young petals as explant, the medium supplemented with different hormones can induce to form distinct neoformations, 2,4-D can only induce the explant to form callus; 6-BAP can induce to redifferentiate vegetative buds; zeatin can induce directly to redifferentiate floral buds. (ⅱ) On the medium supplemented with zeatin, petal and floral stems can be induced directly to redifferentiate floral buds, while young leaves and bulbscales only to redifferentiate vegetative buds. (ⅲ) On the medium supplemented with zeatin, the petals excised from the floral buds formed by petals cultured in vitro can continuously redifferentiate the floral buds, but the young leaves excised from the young vegetative buds which were formed by petals cultured in vitro only redifferentiate vegetative buds. Experimental results show     

SYNTHESIS OF LANSFORDITE MgCO_3·5H_2O AND ITS CRYSTAL STRUCTURE INVESTIGATION

Euhedral crystals of the uncommon low-temperature mineral lansfordite have been obtained by the synthetic method, and the crystal structure analysis has been accomplished correspondingly. The structural parameters and the general view of structure were presented for the first time. The results obtained show that the coordination configuration of two magnesium ions in the unit cell is octahedral arrangement and the coordination number is 6, but in two forms: one in the complex ion Mg(CO_3)_2(H_2O)_4~(2-) and the other in the Mg(H_2O)_6~(2+). There is only a CO_3~(2-) group in the structure, not three distinct groups as reported by Hill et al. previously based on the IR absorption spectrum research data. The authors of this paper believe that the exact chemical formula of lansfordite should be expressed as "Mg(H_2O)_6. Mg(CO_3)_2 (H_2O)_4", and MgCO_3-5H_2O is only a simple chemical expression.     

铝波导钎焊前 储能氩弧点焊点固工艺及设备研制

一、前言电子工业微波元件生产,特别是铝制波导元件钎焊生产中,由于铝波导结构复杂,组并零件多、尺寸精度要求高,例如平板裂缝天线有的用十几根波导管组并成平面板,     

IMS网络安全机制及安全性分析

详细介绍了IMS网络的安全机制，包括IMS接入网与核心网的安全机制，同时介绍了IMS安全规范目前的进展情况，最后对IMS网络安全性进行了分析。     

石英单基多谐振器力敏特性与加力方位的关系

根据石英晶体振动理论及力敏特性,在同一圆形晶体基片上设计制作了多个石英晶体谐振器.采用对径加力的方式,研究了这种石英单基多谐振器的力敏特性与加力方位的关系,并与传统的单基单电极谐振器的力敏特性进行了比较.实验结果表明,同一晶体基片上不同位置的谐振器的力敏特性与加力方位密切相关;选择适当的加力方位,可使多电极结构的谐振器的力-频转换系数优于单电极谐振器的力-频转换系数.     

基于TMP87P809N的家用电器远程控制系统的设计

为了使家用电器的远程控制更加方便灵活,通过分析振铃检测、DTMF解码和实时时钟DS12887的原理,给出了基于电信网络和东芝单片机TMP87P809N的系统设计方案.针对ISD2590的信息检索模式提出了M1和M6两种模式相结合的使用方法,并详细介绍了关键电路的工作原理,对系统的抗干扰措施进行了讨论.经过系统实际运行,验证了该系统的有效性和实用性,达到了系统的设计要求.     

双有源区隧道再生半导体激光器温度场分布研究

针对隧道再生半导体激光器,建立了内部的热源分布模型,分析了三种封装方式对芯片内部温度分布的影响;模拟结果表明加电后几微秒的时间内,芯片内温度场分布主要由隧道再生结构的热特性决定,与封装形式关系不大;在几微秒到几十或一百毫秒的时间范围内,有源区的温度上升很快;几百毫秒以后,器件温度达到稳态,有源区的平衡温度主要决定于载体的散热特性.稳态时靠近衬底的有源区温度高于靠近热沉的有源区的温度,但两有源区的温差很小,芯片内最高温度出现在靠近衬底有源区的脊形中心.     

南京鼓楼检阅台爆破拆除

本文介绍了在建筑群密集,人口稠密、交通频繁的闹市区,运用控制爆破成功地拆除大型废旧建筑物的一个实例。文中叙述了装药配置、药量计算、电点火线路的设计、实际施工、安全防护和爆破效果等项工作,为拆除城市废旧建筑物提供了一些经验。