绝缘环打火研究

绝缘问题是高电压、高场强器件和设备中不可回避的问题,是决定器件、设备运行参数和稳定性的重要因素。针对一台直线感应加速器调试中出现的加速腔绝缘环在带束负载情况下的真空沿面闪络现象,进行了分析和研究。分析表明,在排除设计、材料、加工、洁净和真空度等常规异常因素后,导致绝缘环真空沿面闪络的可能因素是电子在绝缘环表面的吸附和累积,绝缘环上累积的电子来源和加速器中加速、传输的电子束的丢失有关。从加速腔工作状态出发,分析绝缘环表面积累电荷和丢失电子束的相关途径,进而提出相应的技术措施,以提高加速腔运行稳定性。     

Polarization in D-shaped fiber modulated by magneto-optical dichroism of magnetic fluid

The polarization of a D-shaped fiber is modulated after immersing it in magnetic fluid(MF)and applying a magnetic field.Theoretical analysis predicts that magneto-optical dichroism of MF plays a key role in light polarization modulation.During light polarization modulation,the evanescent wave polarized parallel to the magnetic field has greater loss than its orthogonal component.Light polarization of a D-shaped fiber with a wide polished surface can be modulated easily.High concentration MF and a large magnetic field all have great ability to modulate light polarization.     

Evaluation of Charged Defect Energy in Two-Dimensional Semiconductors for Nanoelectronics: The WLZ Extrapolation Method

Defects play a central role in controlling the electronic properties of two-dimensional (2D) materials and realizing the industrialization of 2D electronics. However, the evaluation of charged defects in 2D materials within first-principles calculation is very challenging and has triggered a recent development of the WLZ (Wang, Li, Zhang) extrapolation method. This method lays the foundation of the theoretical evaluation of energies of charged defects in 2D materials within the first-principles framework. Herein, the vital role of defects for advancing 2D electronics is discussed, followed by an introduction of the fundamentals of the WLZ extrapolation method. The ionization energies (IEs) obtained by this method for defects in various 2D semiconductors are then reviewed and summarized. Finally, the unique defect physics in 2D dimensions including the dielectric environment effects, defect ionization process, and carrier transport mechanism captured with the WLZ extrapolation method are presented. As an efficient and reasonable evaluation of charged defects in 2D materials for nanoelectronics and other emerging applications, this work can be of benefit to the community.     

Heat conductivity and Dufour effect in the weakly ionized,magnetized, and kappa-distributed plasma

By using the generalized Boltzmann equation of transport and the first-order approximation of Chapman-Enskog expansion on the κ-distribution function, we study the thermal conductivity and Dufour effect in the weakly ionized and magnetized plasma. We show that the thermal conductivity and Dufour coefficient in the κ-distributed plasma are significantly different from those in the Maxwell-distributed plasma, and the transverse thermal conductivity and Dufour coefficient in the κ-distributed plasma are generally greater than those in the Maxwell-distributed plasma, and the Righi-Leduc coefficient and Hall Dufour coefficient in the κ-distributed plasma are also generally greater than those in the Maxwell-distributed plasma.     

关于(?)-拟微分核的连续性

Supposa that f(x) is a quasidifferentiable function, defined on S(?)R~n where S is an open set, with a -equivalent bounded quasidifferential subfam ily. Lenma I     

制备工艺对多孔阳极氧化铝特性的影响

通过对草酸溶液中制备的多孔阳极氧化铝(PAA)的形貌、晶态结构和光致发光(PL)特性的表征和机理分析,研究了草酸电解液浓度、阳极氧化电压和退火等丁艺对PAA的形成及特性的影响.PAA的孔径在50～120 nm之间,且随着阳极氧化电压的升高而增大,而受电解液浓度的影响较小.X射线衍射结果表明:PAA为非晶态结构,退火之后结晶,并有多相共存.PL测试表明PAA在375～500 nm之间有一较宽的蓝色发光带,发光峰在425 nm左右,是由氧空位引起的,且其峰强可通过改变阳极氧化电压和草酸浓度等参数来调制.     

非掺杂GaN的黄光发射模型确定

提出了一种新的光谱———吸收归一化光致发光激发谱,并用这种光谱研究了非掺杂GaN的黄光发射.实验上首次直接测量出了黄光发射的初始态的共振吸收峰位,从而解决了长期争论的有关黄光发射的发光模型问题 关键词： GaN薄膜 黄光发射 吸收归一化光致发光激发谱