水资源持续利用的多目标决策模型的建立

可持续发展战略的实施,资源的可持续利用是关键.针对日趋短缺的淡水资源,根据多目标决策理论,以同时追求经济、环境、社会效益为主要目标提出了其可持续利用的多目标决策模型,并举例说明了模型的应用,旨在为决策者提供淡水利用规划的依据.     

矩阵算法在多目标投资决策中的应用

用于解决多目标决策的传统方法有线性加权法、理想点法、平方和加权法等方法,但采用不同的方法得到的结果并不完全相同。为了克服传统方法的不足之处,提出了基于估计相对位置的方案排队法来解决多目标决策问题。     

A novel 4H-SiC lateral bipolar junction transistor structure with high voltage and high current gain

In this paper, a novel structure of a 4H-SiC lateral bipolar junction transistor (LBJT) with a base field plate and double RESURF in the drift region is presented. Collector-base junction depletion extension in the base region is restricted by the base field plate. Thin base as well as low base doping of the LBJT therefore can be achieved under the condition of avalanche breakdown. Simulation results show that thin base of 0.32 μm and base doping of 3×1017 cm-3 are obtained, and corresponding current gain is as high as 247 with avalanche breakdown voltage of 3309 V when the drift region length is 30 μm. Besides, an investigation of a 4H-SiC vertical BJT (VBJT) with comparable breakdown voltage (3357 V) shows that the minimum base width of 0.25 μm and base doping as high as 8×1017 cm-3 contribute to a maximum current gain of only 128.