An experimentally verified hybrid Cassie-Mayr electric arc modelfor power electronics simulations

This paper presents an electric arc model that can approximately represent both the static and dynamic characteristics of an arc load controlled by a power electronic circuit. The proposed model was developed from the combination and modifications of the classical Cassie and Mayr equations. The model equations have been expressed in a form suitable for incorporation into circuit simulators employing the nodal analysis method of equation solving. The model has been test-implemented in the Saber circuit simulator. Simulated and experimental results appear to be in good agreement     

IEEE standard 802.16: a technical overview of theWirelessMANTM air interface for broadband wirelessaccess

The broadband wireless access industry, which provides high-rate network connections to stationary sites, has matured to the point at which it now has a standard for second-generation wireless metropolitan area networks. The IEEE standard 802.16, with its WirelessMAN^TM air interface, sets the stage for widespread and effective deployments worldwide. This article overviews the technical medium access control and physical layer features of this new standard     

Fluorescence anisotropy decay study of self-association of bacterial luciferase intermediates

The fluorescence dynamics parameters of the fluorescent transient flavin-luciferase species from the typesVibrio fischeri andPhotobacterium leiognathi are presented. The fluorescence anisotropy decay is a single exponential function for both types. The correlation time is 70 ns for theP. leiognathi fluorescent transient intermediate (2°C, aqueous buffer, pH 7.0), consistent with the rotational correlation time of the luciferase macromolecule (77 kD) to which the flavin fluorophore is rigidly attached. In contrast, for theV. fischeri species the observed correlation time for the anisotropy decay function is 133 ns. This suggests that protein self-association occurs in theV. fischeri case and this is confirmed by filtration, where the fluorescent transient fromV. fischeri does not pass through a 100,000 molecular weight cutoff membrane, whereas theP. leiognathi species does. The filtration method also demonstrates self-association in the luciferase peroxyflavin and photoflavin fromV. fischeri. A monomer-dimer equilibrium also explains the previously reported high correlation times for theV. harveyi luciferase-flavin species. It is proposed that the self-association competes with the lumazine protein interaction in the bioluminescence reaction.     

Glass transitions in hydrogen-bonded polymer complexes

Mutual precipitates of poly (N, N-dimethyl acrylamide) and poly (4-hydroxystyrene) were collected from dioxane, methanol, or acetone. The glass transition (T_g) temperatures of the precipitates are higher than the weight-average values. Clear films cast from dimethylformamide solutions have lower T_g values. Complexation also occurred between poly (ethyl oxazoline) and poly (4-hydroxystyrene) in dioxane and between poly (vinyl pyrrolidone) and poly (4-hydroxystyrene) in methanol. Again, the glass transition temperatures of the precipitates are higher than the values for the blend films. The ΔC_p values associated with the glass transitions of the complexes are smaller than those of the blends having the same compositions. Negative excess heat capacities of mixing have been observed for several precipitates.     

A bartlett-type adjustment for the likelihood ratio statistic with an ordered alternative

For testing the equality of normal variances with an increasing alternative, under the null hypothesis the likelihood ratio test statistic is asymptotically distributed as a mixture of chi-squared distributions. In this paper a Bartlett-type adjustment is proposed to improve the approximation of the null distribution of the likelihood ratio test statistic with an ordered alternative.     

Ca原子的Penning离化

用614.3nm染料激光照射以Ne为缓冲气体的Ca空心阴极灯,观察到了Ca原子的Pen-ning离化效应。对比在Li空心阴极灯中获得的光电流信号,解释了Ca原子的彭宁离化。     

动态聚焦电子枪的模拟与实验研究

动态聚焦技术是为了满足大屏幕高分辨率彩色显像管及高分辨率彩色显示管的发展需求而产生的一项新技术。在本文中，作者首先提出了一种动态聚焦电子枪结构，进行了数值计算与分析，制作了动态聚焦电子枪并装管实验。通过对实验样管的测试与分析。证实该枪性能良好，动态聚集效果明显。     

综合联机指令系统及其应用

介绍了综合联机指令系统的业务功能、处理流程和软件架构,并举例说明了该系统的应用。     

Nb2O5掺杂对ZnO压敏电阻器电性能的影响

本文研究了Ｎｂ＿２Ｏ＿５掺杂以及Ｎｂ＿２Ｏ＿５与ＺｎＯ煅烧对ＺｎＯ压敏电阻器电性能的影响。实验表明，Ｎｂ＿２Ｏ＿５的掺入使压敏电场减少，当Ｎｂ＿２Ｏ＿５含量为０．１％ｍｏｌ时，其压敏电场最小．非线性系数最大。煅烧温度越高，压敏电场越高，非线性系数越大。     

一种简易可靠的射频激光调制器

采用ＰＩＮ电调衰减器、ＴＬ４９４等元件组成了射频（ＲＦ）大功率ＣＯ２激光调制器，调制频率、占空比和调制度单独可调。给出了电路的工作原理和测试结果。