湍流型CVD反应器中生长晶体Si的模拟与分析

Numerical simulation, based on simple reaction models that manifest the deposition quality of silicon from silane, was undertaken to investigate the horizontal reactor, with longitudinal and transversal aspect ratios of 10 and 4, respectively. The effects of Rayleigh （Ra） and Reynolds （Re） numbers on the Si deposition rate in these turbulent-type reactors are discussed. The results show that the time-averaged deposition rate is fairly uniform and fast, although the instantaneous deposition is non-uniform in these turbulent reactors. In addition, the increase of the Re number within a certain range can compensate for the path loss of the reactant and obviously enhance the downstream deposition rate, but deteriorate the transverse distribution of the deposition.     

基于多时相Sentinel-2影像的黑河中游玉米种植面积提取研究

玉米是黑河中游种植面积最大的农作物,生长期需水量大、蒸散量高.准确获取玉米种植面积对该区域农作物种植结构调整、水资源合理规划有重要参考意义.基于2019年4月至9月Sentinel-2多时相影像,采用随机森林算法开展了黑河中游玉米种植面积提取研究.研究方法分为两类—直接提取法和两步提取法.进一步探讨了多时间信息量对玉米...