Electron Injection by E—Field Drift and its Application in Starting—up Tokamaks at Low Loop Voltage

We propose an innovative method of election injection by E-field drift into a plasma device and discuss its application in starting-up tokamak plasmas at low loop voltage.The experimental results obtained from HT-6M Tokamak are also presented.The breakdown loop voltage is obviously reduced and the discharge performance is improved by using the electron injection method.It could be applied to some other types of plasma device.     

Electromagnetic Instabilities Excited by Electron Temperature Anisotropy

One-dimensional particle-in-cell simulations are performed to investigate the nonlinear evolution of electromagnetic instabilities excited by the electron temperature anisotropy in homogeneous plasmas with different parameters. The results show that the electron temperature anisotropy can excite the two right-hand electromagnetic instabilities, one has the frequency higher than Ωe, the other is the whistler instability with larger amplitude, and its frequency is below Ωe. Their dispersion relations are consistent with the prediction from the cold plasma theory. In the initial growth stage (prediction from linear theory), the frequency of the dominant mode (the mode whose amplitude is large enough) of the whistler wave almost does not change, but in the saturation stage the situation is different. In the case that the ratio of electron plasma frequency to cyclotron frequency is larger than 1, the frequency of the dominant mode of the whistler wave driRs from high to low continuously. However, for the case of the ratio smaller than 1, besides the original dominant mode of the whistler wave whose frequency is about 2.6ωe, another dominant mode whose frequency is about 1.55ωe also begins to be excited at definite time, and its amplitude increases with time until it exceeds the original dominant mode.     

a-Si:H薄膜及MWECR-CVD制备技术

文章回顾了a—Si：H薄膜的发展历程，并介绍了其近10年的研究状况、为提高a—Si：H薄膜的沉积速度，还重点介绍了一种新的微波电子回旋共振等离子体CVD(MWECR—CVD)技术，该技术的特点是：不含电极，可避免电极溅射造成的污染；等离子区离子密度高，对硅烷能高度分解，从而可显著提高薄膜生长速率；改变磁场位形和结构，可改变等离子体分布及轰击基片离子的能量，文章还分析了其制备a—Si：H薄膜存在的问题，提出了今后的研究方向。     

Hk流的微分Harnack 估计

对k>0,得到了在Rⁿ⁺¹中的H^k流的解的微分Harnack估计. 应用这个估计, 得到了关于H^k-流迁移孤立子的一些性质.     

氧分子对电子偶素的态转换

把气凝硅胶作为可变能量的电子偶素源,用时间选择γ能谱仪研究电子偶素在氧气中的运动,验证快速电子偶素与氧分子非弹性碰撞发生的态的转换效应,测得在两个阈能附近的截面为2.1×10^－17cm²和6.6×10^－18cm².研究慢速电子偶素与氧分子弹性碰撞交换电子所致态转换,发现过程的截面与电子偶素平均速度的平方根成反比,这一过程可以提供比较干净的仲态电子偶素源进行其它精密物理实验.     

HM-J16双光子电子直线加速器

简要叙述了 HM-J1 6加速器的设计思想和设计特点。设计了一台采用射频功率反馈的射线能量范围为 6～ 1 6Me V的双光子电子直线加速器。其最大辐射野为 4 0 cm× 4 0 cm,双光子剂量率均大于3 60 c Gy/ (min·m)。     

一类积分—微分方程离散谱的存在性

本文讨论在迁移理论中出现的一类较广泛的积——微分方程,研究方程所确定的算子的离散谱存在的充分必要条件,并给出了离散谱存在的一个充分条件。     

单电子能量的解析隐函数表示

本文提出多核体系中单电子能量的解析隐函数表示。此方法建立在直接空间里的原子轨道线性组合和动量空间里波函数的表示。从理论上讲,任何级别的精确值都可以用叠代法求得。文中还讨论了此方法在和键角键长变化有关的分子课题中的可能应用。     

Photochemically Catalyzed Diels-Alder Reaction of Azadienes with 2,3-Dihydrofuran by 2, 4, 6-Triphenylpyrylium Salt： Synthesis of Styrylfuroquinoline Derivatives

Photochemically promoted Diels-Alder reactions of 1, 4-diaryl-1-azabutadienes with 2,3-dihydrofuran were achieved by using 2, 4, 6-triphenylpyrylium tetrafluoroborate as catalyst to produce corresponding styrylfuroquinolines in high yield.     

库珀对何时不配对

在低温超导体中，电子并不是单个地进行运动，而是以弱耦合形式形成配对，一般称之为库珀对．形成库珀对的两个电子，一个自旋向上，另一个自旋向下．最近德国科学家D．Beckmann教授对库珀对的分离作了一些实验，他的实验表明库珀对中的电子可以在它们的有效作用距离内发生分离。