A Novel Contactless Method for Characterization of Semiconductors：Surface Electron Bean Induced Voltage in Scanning Electron Microscopy

We present a novel contactless and nondestructive method called the surface electron beam induced voltage (SEBIV) method for characterizing semiconductor materials and devices.The SEBIV method is based on the detection of the surface potential induced by electron beams of scanning electron microscopy (SEM).The core part of the SEBIV detection set-up is a circular metal detector placed above the sample surface.The capacitance between the circular detector and whole surface of the sample is estimated to be about 0.64pf.It is large enough for the detection of the induced surface potential.The irradiation mode of electron beam (e-beam) influences the signal generation When the e-beam irradiates on the surface of semiconductors continuously,a differential signal is obtained.The real distribution of surface potentials can be obtained when a pulsed e-beam with a fixed frequency is used for irradiation and a lock-in amplifier is employed for detection.The polarity of induced potential depends on the structure of potential barriers and surface states of samples.The contrast of SEBIV images in SEM changes with irradiation time and e-beam intensity.     

激光光控超导YBa2Cu3Ox薄膜开关的研制

在对光控热电效应开关进行理论分析的基础上,木文提出用YBa₂Cu₃O_x薄膜制作光控开关,并测试了在液氮温度下薄膜开关在不同激光波长下的特征参数,测试的最好结果是响应度R_v(632.8nm,10kHz,1Hz)为217V/W,归一化探测率D_*(632.8nm,10kHz,1Hz)为2.3×10¹¹cm.Hz^1/2/W,响应时间τ为0.21ms.     

杨氏双缝干涉图样的理论模拟

本文在未经任何理论近似的情况下, 模拟了杨氏双缝干涉实验中观察屏上的干涉图样, 模拟结果不但 有利于学生全面掌握干涉条纹的分布规律, 而且有助于学生体会实验条件的重要性     

间接馈电柱-锥级联爆磁压缩发生器数值模拟

为了研究间接馈电、两级级联柱-锥构型的爆磁压缩发生器的物理特性，发展了描述爆磁压缩物理过程的2维爆轰磁流体力学程序——MFCG（Ⅴ），并用其分析、计算了一系列模型。通过将计算结果与柱-柱构型的结果进行比较，表明了柱-锥构型更有利于功率放大:在同样的输出电流条件下，不仅爆磁压缩的时间缩短，而且输出功率也相应地增加。MFCG（Ⅴ）程序的建立以及相应的数值模拟结果有助于加深对柱-锥构型的爆磁压缩发生器物理过程的认识，并为实验设计提供参考。     

Surface oxidation of vanadium dioxide films prepared by radio frequency magnetron sputtering

This paper reports that the thermochromic vanadium dioxide films were deposited on various transparent substrates by radio frequency magnetron sputtering, and then aged under circumstance for years. Samples were characterized with several different techniques such as x-ray diffraction, x-ray photoelectron spectroscopy, and Raman, when they were fresh from sputter chamber and aged after years, respectively, in order to determine their structure and composition. It finds that a small amount of sodium occurred on the surface of vanadium dioxide films, which was probably due to sodium ion diffusion from soda-lime glass when sputtering was performed at high substrate temperature. It also finds that aging for years significantly affected the nonstoichiometry of vanadium dioxide films, thus inducing much change in Raman modes.     

大学物理双语教学实践与研究

大学物理是国内外理工科大学基础课中非常重要的一门课程.开展和推进双语教学工作是高等教育国际化的重要内容之一.大学物理学教学模式的改革是教学改革的主要内容之一.笔者在大学物理教学中,选用英文原版优秀教材与中文教材相结合的新颖的双语教学模式,教学与国际接轨,激发学生学习兴趣,培养学生综合创新能力,提高学生科学素养.文章结合我校非物理专业"大学物理"双语教学的实际情况,介绍大学物理双语教学目的、研究方法和具体措施;客观评价了大学物理双语教学效果.     

大学物理学(上下册)

正出版社:清华大学出版社简介:中国农业大学新编教材。受益于编者20余年普通物理教学经验,本教材在内容上精心编写,结构合理,难点处理得当,尤其适合于应用技术型本科普通物理课程教学使用。主要有以下四个特点:(1)考虑不同需求,内容划分层次。标有"※"     

突出文化特色的大学物理教学模式

大学物理学教学模式的改革是教学改革的主要内容之一。对理工科大学非物理专业的学生来说,"大学物理学"本身的学科角色已不是那么突出,物理学中的思维方法和哲学等文化的学习变得比物理知识本身更重要。作者在大学物理教学中,尝试突出物理学文化特色的教学模式,激发学生学习兴趣,培养学生跨学科思考的能力,提高学生科学素养。通过大学物理学的教与学,帮助学生养成良好的文化修养和创新精神。