Superior material qualities and transport properties of InGaN channel heterostructure grown by pulsed metal organic chemical vapor deposition

Pulsed metal organic chemical vapor deposition is introduced into the growth of In Ga N channel heterostructure for improving material qualities and transport properties. High-resolution transmission electron microscopy imaging shows the phase separation free In Ga N channel with smooth and abrupt interface. A very high two-dimensional electron gas density of approximately 1.85 × 1013cm-2is obtained due to the superior carrier confinement. In addition, the Hall mobility reaches 967 cm2/V·s, owing to the suppression of interface roughness scattering. Furthermore, temperature-dependent Hall measurement results show that In Ga N channel heterostructure possesses a steady two-dimensional electron gas density over the tested temperature range, and has superior transport properties at elevated temperatures compared with the traditional Ga N channel heterostructure. The gratifying results imply that In Ga N channel heterostructure grown by pulsed metal organic chemical vapor deposition is a promising candidate for microwave power devices.     

面向电力虚拟社区的隐性知识云处理模型

当前电力虚拟社区中非结构化的隐性知识资源数量与日俱增,然而由于其中自由的问答交流模式,导致解决具体问题的隐性知识淹没于大量的无效信息中,电力相关从业人员难以快速从中获取适用性好的隐性知识;同时,随着电力虚拟社区的大规模扩张,激增的数据量将带来存储扩展性和快速检索的问题.为此提出一种面向电力虚拟社区的隐性知识云处理模型MPTKKM.模型以模式匹配算法为核心,设计了可以自动建立电力隐性知识应用情景描述关键词序列的隐性知识收集算法,采用分布式键值对的存储模式,并基于云计算技术实现了电力隐性知识检索.实验结果表明,提出的模型不但能自动收集适用性好的电力隐性知识,而且云检索算法表现出了良好的可扩展性.