Integrated Behavior of Carbon and Copper Alloy Heat Sink Under Different Heat Loads and Cooling Conditions

An actively water-cooled limiter has been designed for the long pulse operation of an HT-7 device, by adopting an integrated structure-doped graphite and a copper alloy heat sink with a super carbon sheet serving as a compliant layer between them. The behaviors of the integrated structure were evaluated in an electron beam facility under different heat loads and cooling conditions. The surface temperature and bulk temperature distribution were carefully measured by optical pyrometers and thermocouples under a steady state heat flux of 1 to 5 MW/m^2 and a water flow rate of 3 m^3/h, 4.5 m^3/h and 6 m^3/h, respectively. It was found that the surface temperature increased rapidly with the heat flux rising, but decreased only slightly with the water flow rate rising. The surface temperature reached approximately 1200℃ at 5 MW/m^2 of heat flux and 6 m^3/h of water flow. The primary experimental results indicate that the integrated design meets the requirements for the heat expelling capacity of the HT-7 device. A set of numerical simulations was also completed, whose outcome was in good accord with the experimental results.     

MOCVD法侧向外延生长高质量GaN

利用金属有机物气相外延法(MOCVD),在GaN/蓝宝石复合衬底上,采用侧向外延生长技术制备出高质量的GaN外延膜,并对其进行扫描电镜、X射线双晶衍射、透射电镜测量和分析.发现完全合并后的GaN外延层的表面平整,晶体质量较衬底有大幅的提高,透射电镜进行微区位错观察发现窗口区穿透位错大部分发生转向,侧向生长区下方的穿透位错被掩膜阻断.     

收藏记忆——咖啡里追寻时光

许多事情，总在转身的霎那，被我们轻易地尘封在时间的阁楼，一个阳光慵懒的午后，在咖啡弥漫的香气里，蓦然发现，原来，记忆一直不曾走远，只不过被我们一不小心收藏了起来。     

建筑装饰装修引发的结构安全问题

探讨了人们在平常家装中有意或无意地改变了建筑结构体系或改变建筑使用功能荷载,给建筑使用安全、寿命带来隐患,提醒人们在家装中的安全注意事项,确保建筑有设计的抗震能力。     

利用传输矩阵法分析取样光栅DBR半导体激光器

取样光栅DBR(SGDBR)激光器是目前光通讯中最有应用前景的可调谐激光器之一。利用传输矩阵法模拟了取样光栅DBR半导体激光器的光谱特性。计算中,把取样光栅DBR半导体激光器的增益区、位相区和取样光栅DBR看成基本单元。而每一个基本单元都可以看作一个普通的双端口器件。其传输特性用一个2×2复矩阵表示。在阈值以下,对于有源区和取样光栅DBR的不同注入电流,发射光谱显示不同的输出特征。当有源区的注入电流为9.5 mA时,主模开始在1.553μm附近形成。当取样光栅DBR有注入电流时,主模形成的位置发生了变化,表现出可调谐的性质。同时,明显出现主模的有源区的注入电流发生变化。这种方法也反映了激光器的阈值条件。阈值电流为10 mA。     

电力工程中招投标的风险分析和管理

本文对电力工程建设中业主和承包商在招投标阶段工作的核心内容进行了分析探讨。     

氯气泄露事故的特点、预防及处置对策

氯气是广泛存在于多种工业的有害气体。用于制造农药，漂白剂，消毒剂，合成纤维以及其他氯化物等，除了上述化工企业，城市自来水厂，学校实验室等也有氯气。     

丹江口大坝加高堰顶溢流段施工渡汛试验研究

阐述了南水北调工程丹江口大坝加高施工期渡汛时的主要试验成果.通过128 m高程平台与三级台阶两个方案的试验成果表明:泄流能力满足设计要求;牛腿安装在封堵门槽后,无阻水现象;坝面平台后存在负压,闸墩工作门槽后有4.0×9.81 kPa的负压;水流出平台有脱空现象;挑流水舌打击护坦,而三级台阶方案无打击护坦现象.