水行政执法中部分具体行政行为的法律性质探析

关于<中华人民共和国水法>、<江苏省水利工程管理条例>等水法律法规中规定的一些具体行政行为的法律性质,学理界一直存在争议.本文根据多年水行政执法活动积累的经验,谈谈对"责令改正或限期改正违法行为"、"强行拆除"等水行政执法过程中的具体行政行为的不同理解,希望能够对水行政执法实践起到一定的借鉴作用.     

AlGaAs:Si中与DX中心有关的光生电子陷阱特性研究(英文)

A new electron trap state SD was found by DLTS measurement under light illumination in Si doped A.lxGa1-xAs. This new trap energy level ESD is shallower than the DX center energy in the gap and the concentration of SD is comparable to that of DX centers. The emission activation energy Ec=0.20±0.05eV and capture activation energy Ec= 0.17±0.05eV. The SD DLTS peak has never been detected previously because under dark and thermal equilibrium condition most of the electrons occupy the deeper DX states and most of SD states are empty. However, when the sample is illuminated by light, electrons are excited to the conduction band and then re-captured by SD since the deeper DX states have a slower electron capture rate, thus a new DLTS peak corresponding to SD appears. Constant temperature capacitance transient C-t and transient C-V measurements were also used to further confirm the existence of SD states.     

从IPv4到IPv6的技术革新

IPv6(Internet Protocol version 6)是建设移动信息社会的重要基石，是集移动性、安全性和质量为一体的最佳选择。随着互联网的发展，IPv4暴露出来的缺陷越来越不适应发展的要求，顺利实现从IPv4到IPv6的过渡将会有力地促进互联网迈向新的层次。在这场较量中，将给中国提供一次追赶国外厂商的机会。     

铝材在汽车制造技术中的应用

介绍车用铝材的优良性能和研发情况，以及各种车用特种材料和铝制汽车零部件。     

无源光纤网络（PON）技术

该文主要阐述了PON（无源光网络）技术的概念，特点，市场定位，关键技术，优势和应用。