真空绝缘子脉冲表面电场在线测量系统的实现

基于Kerr电光效应,建立了用以对纳秒脉冲高电压作用下的真空绝缘子表面电场进行在线测量的实验系统。该测量系统由快脉冲高电压源、YAG激光器、同步控制系统、被测中空薄壁绝缘子及Kerr效应单元、光学相位差检测系统等部分构成。利用YAG激光器输出的激光脉冲,触发导通快脉冲高压源中的高压气体开关,使其给被测绝缘子试品上施加一个脉宽100ns的高压脉冲方波。利用同步控制,使得探测激光在试品上的脉冲方波达到幅值后,入射到Kerr腔体中对Kerr效应进行探测。从而实现了对绝缘子表面电场的在线测量,并给出了初步的测量结果。     

抑制大型折叠腔结构光斑抖动技术的研究

针对光腔镜盒的真空变形和振动对精密光学系统的影响,分析了传统刚性连接的光学调整架平台以及球关节连接结构在减振降噪设计的不足,从支撑和柔性密封连接的角度,设计了隔离振动和光腔镜盒真空变形的精密光学调整架平台,对应用于大型折叠腔的双层光学调整架平台的动力学特性进行ANSYS仿真,并完成了光斑抖动验证实验。结果显示框架式双层光学调整架平台的第一阶弹性体频率可达到126.5,172.3Hz,很好地满足折叠腔光学调整架平台的使用要求;应用在大型折叠腔,抽真空试验前后He-Ne导引光输出光斑位置无变化,形状变化很小,出光过程中输出抖动角均方根值为3.73″,隔离振动传递效果明显。     

Generalized Hyperfocused Arcs in

A generalized hyperfocused arc in is an arc of size k with the property that the secants can be blocked by a set of points not belonging to the arc. We show that if q is a prime and is a generalized hyperfocused arc of size k, then or 4. Interestingly, this problem is also related to the (strong) cylinder conjecture ( 2 , 5 Problem 919), as we point out in the last section.     

On Small Complete Arcs and Transitive ‐Invariant Arcs in the Projective Plane

Let q be an odd prime power such that q is a power of 5 or (mod 10). In this case, the projective plane admits a collineation group G isomorphic to the alternating group A₅. Transitive G‐invariant 30‐arcs are shown to exist for every . The completeness is also investigated, and complete 30‐arcs are found for . Surprisingly, they are the smallest known complete arcs in the planes , and . Moreover, computational results are presented for the cases and . New upper bounds on the size of the smallest complete arc are obtained for .     

保形闭圆弧样条插值的改进算法

在CNC加工中,直线段和圆弧是加工路径的重要组成部分.而圆弧样条的段数和曲线的保形性,是比较重要而且富有实际意义的.提出了一种改进的G1圆弧样条保形插值算法,该算法在型值点列满足较弱的条件下,具有圆弧段数较少,并且保形的特点.     

Comment on 'The scale-transformation of electromagnetic theory and its applications', 'Distribution characteristic of scattering field for an ellipsoidal target irradiated by an electromagnetic wave from an arbitrary direction' and 'Electric fields inside

It is shown that the 'scale-transformation' method proposed by Li Ying-Le et al. is not applicable to the Maxwell theory.     

Comment on ＇The scale-transformation of electromagnetic theory and its applications＇, ＇Distribution characteristic of scattering field for an ellipsoidal target irradiated by an electromagnetic wave from an arbitrary direction＇ and ＇Electric fields inside and outside an anisotropic dielectric sphere＇

It is shown that the ＇scale-transformation＇ method proposed by Li Ying-Le et al. is not applicable to the Maxwell theory.     

Novel Dy^3＋-doped Gd（PO3）3 white-light phosphors under VUV excitation for Hg-free lamps application

Novel Dy3+-doped Gd(PO3)3 white light phosphors each with an orthorhombic system are successfully synthesized by solid-state reaction.The luminescence properties of white-light Gd1-x(PO3)3:xDy3+(0 x ≤ 0.25) under vacuum ultraviolet(VUV) excitation are investigated.The strong absorption at around 147 nm in excitation spectrum energy can be transferred to the energy levels of Dy3+ ion from the host absorption.Additionally,the white light phosphor is activated by a single Dy3+ ion.Therefore,the luminescence of Gd1-x(PO3)3:xDy(0 x ≤ 0.25) under VUV excitation is effective,and it has the promise of being applied to mercury-free lamps.     

Leaching kinetics of electric arc furnace dust in nitric acid solutions

Electric arc furnace dust contains mainly ZnO, ZnFe₂O₄, and iron oxides. In this study, chemical composition of ZnO, ZnFe₂O₄, and Fe₂O₃ and leaching kinetics of ZnO, ZnFe₂O₄, and Fe₂O₃ in HNO₃ solutions were investigated. It was seen that the dissolution of ZnO is very fast, therefore the leaching kinetics of ZnO cannot be determined. Kinetic parameters and model equations were derived for the leaching of ZnFe₂O₄ and Fe₂O_3. Leaching kinetics of ZnFe₂O₄ was explained by the pseudohomogeneous reaction model. Activation energy and order of HNO₃ concentration were found to be as 37.5 kJ mol⁻¹ and 0.37, respectively. The model equation was derived as . It was determined that experimental data for the leaching kinetics of Fe₂O₃ best fit with the shrinking core model (SCM). Activation energy and order of HNO₃ concentration were found to be as 51.5 kJ mol⁻¹ and 0.67, respectively The model equation was derived using SCM as _.     

G-M制冷机气缸组件焊接工艺初探

气缸组件由整体式改为分体式,就面临一个焊接问题。二级气缸级间法兰与一级气缸缸体相连,采用微热氩弧焊焊接;用焊接芯棒保证一、二级气缸的同轴度及气缸组件的长度尺寸;焊接时使用螺孔定位工装保证一、二级冷头上各螺孔在图示位置,不得错位。对气缸组件的焊接工艺作了初步的分析与探索。