浅N~+-P结雪崩电子有效发射的掺杂剖面计算(英文)

A very shallow N-P junction has been produced on a silicon substrate using a low energy ion implantation(≤25keV) followed by suitable annealing. The junction is in parallel to the silicon surface and able to emit electrons out of the surface when biased in avalanche breakdown. The number of emitting electrons significantly depends on doping profiles, junction depth, and work function of the electron emitting material.This paper reports the calculation of the optimum theoretical doping profiles. The calculation indicates that the N+ layer thickness must be of the order of 100A to obtain high efficiency η defined as the number of electrons emission out of Si surface per total number of avalanche electrons. The experimental results of the N+-P junction with desirable doping profiles will also be presented. This topic is the basic investigation for the design and fabrication of vacuum silicon devices.     

信息技术在高职数学教学的应用探究

应用信息技术辅助高职系数学教学能更好地激发学生的学习兴趣,为学生提供更加丰富的学习资源,帮助学生更好地培养数学思维,感知数学文化,作为教师一方面要正视计算机信息技术的优势,努力寻找信息技术与传统教学模式的有效结合点,提高学生的数学应用能力,造就高质量的技能型人才。     

基于BP网络的空气污染指数预报研究

为了研究对空气污染进行预报的更有效方法,从气象学角度对各种污染物和气象因素进行了分析,在确定了空气污染指数影响因子基础上,综合考虑BP网络的逼近能力和泛化能力,提出了空气污染指数BP网络预报模型,并进行了对比预报检验。结果表明,BP方法预报模型的预报准确度明显高于通常使用的逐步回归方法,特别是对骤升骤降趋势也能得到准确度较高的预报结果。