Characteristics of Dislocation Half-Loop Arrays in 4H-SiC Homo-Epilayer

Dislocation “half-loop arrays” (HLAs) in 4H-SiC homo-epilayers are studied by molten KOH etching and atomic force microscopy (AFM). It is found that the dislocation half-loops in an array exist at different depths in the epilayer, and they are aligned roughly but not exactly perpendicular to the off-cut direction. These results indicate that the dislocation half-loops in an array are not formed simultaneously, but the array extends by generation of new half-loops during growth. It is also demonstrated that the HLAs can be artificially induced by creating strain in the material, followed by annealing.     

Surface photoabsorption monitoring of the growth of GaAs and InGaAs at 650°C by MOCVD

By monitoring the cyclic behavior of surface photoabsorption (SPA) reflectance changes during the growth of GaAs at 650°C and with sufficient H₂ purging time between the supply of trimethylgallium and AsH₃, we have been able to achieve controlled growth of GaAs down to a monolayer. Our results show, as confirmed by photoluminescence (PL) measurements, the possibility of growing highly accurate quantum well heterostructures by metalorganic chemical vapor deposition at conventional growth temperatures. We also present our PL measurements on the InGaAs single quantum wells grown at this temperature by monitoring the SPA signal.     

石榴的化学成分与药理活性

介绍了石榴的化学成分与活性物质,并对石榴的药理活性及其在人体中的作用进行了概述。     

邱村金矿采矿损失贫化管理的探讨

矿石损失与贫化这两项指标,是评价矿床开采的主要技术经济指标,分别表示地下矿产资源的利用情况和采出矿石的质量.文章分析了邱村金矿资源开采中的损失与贫化高的主要原因,提出降低矿石损失贫化的有效措施.     

石化用高压阀门阀体和阀盖连接形式的研究

分析了高压阀门阀体和阀盖的连接形式及其相关标准的规定。提出了石油化工用阀门阀体和阀盖采用压力自紧密封结构连接形式应注意的问题和避免阀门泄漏的辅助措施。     

黄金矿山设备管理的探索

针对黄金矿山设备管理存在的一些问题,提出了加强设备基础管理,用技术、经济、政策手段和现代化管理方法对设备进行管理的工作思路。     

论国外地下装载机的现在与未来

通过分析和介绍世界上著名地下装载机制造商近几年生产的地下装载机之新结构、新特点和新技术,简要介绍了国外地下装载机的现状与发展,以期为我国地下装载机的发展提供参考。     

基于GIS的矿山重大安全隐患决策支持系统探讨

分析矿山重大安全隐患决策支持系统的应用前景,从该系统的总体设计、系统功能结构、数据库建库、系统实现等方面进行探讨,为矿山安全管理信息化设计提供相关参考.     

Synthesis of CaCu3Ti4O12 Micron-cubes and rods via high proportion molten salt method

CaCu₃Ti₄O₁₂ (CCTO) particles were produced from a CuO–CaCO₃–TiO₂ peroxo-hydroxide precursor material in NaCl–KCl and Na₂SO₄–K₂SO₄ salt mixtures via the molten-salt synthesis method at different salt-to-precursor mass ratios. Regular-shaped CCTO particles of cubes, rods, and polyhedrons can be obtained at large salt-to-precursor mass ratios of above 50:1. With the extension of sintering time, the particle shape is more regular and the size is larger. Long micro rods with a length of about 53 μm can be obtained at a mass ratio of 125:1 and a long sintering time of 72 h in sulfate salts. The formation mechanisms are also discussed and the results suggest that a large salt-to-precursor mass ratio may provide a sufficient number of Na − K ions to sufficiently modify the particle shape and form regular-shaped cubes and rod-like particles. At the same time, CCTO ceramics synthesized by Na₂SO₄–K₂SO₄ molten-salt method show good dielectric properties, with a dielectric constant higher than 10⁴ and a loss factor less than 0.45 in the range of 20 Hz to 1 MHz.     

基于精细化工行业风控评价系统研究

就目前精细化工行业风险存在的问题,针对精细化工行业企业,从金融信贷信息、企业运营信息、行业评价信息、诉讼信息、发展能力等5个维度构建指标评价体系,从而设计了一套完整的服务大数据和人工智能时代的监管信息平台体系。通过搭建模型管理架构,建设监控预警、追踪查证为主的业务应用平台,介绍了可以实现精细化工行业风控评价指标以及即时反馈的风险系统,大大降低精细化工行业的风险系数。