基于火花隙开关实现的固体热容激光器实验

在对储能网络的快速恒流充电和氙灯的预燃状态下,通过控制火花隙触发开关上的电压和重复频率,实现“热容”模式下运行的氙灯泵浦钕玻璃激光器的激光输出。初步实验指标达到：重复频率4 Hz,40 J/脉冲,出光25 s,输出能量4 kJ,工作间隙10 min,每次工作出光可将1.5 cm厚的铝板打穿。该激光器的功率输出可定标放大到kW量级以上,适合进行一些固体热容激光器特点的相关实验。     

A coaxial induction probe for measuring the charge,size and distance of a passing object

A coaxial induction probe for measuring the charge, size and distance of a passing object is presented. Two different current signals were induced as an object passed the probes. The signals were integrated and Gaussian curves were fitted to the data. According to simulations done with Comsol Multiphysics, the charge, size and distance could be calculated from the amplitudes and widths of the curves. The system was simulated, built and calibrated. It was tested in powder measurements in a fluidized bed device.     

Multi-scale analysis on the pulverized coal flow behaviors under high pressure dense-phase pneumatic conveying

To deeply knowledge of the flow behaviors of pulverized coal particles in dense gas–solid two-phase flow, a multi-scale analysis method based on electrostatic sensor array is applied for the multi-scale characterization of flow behaviors of dense gas–solid flow. The experimental results indicate that: for steady flow, with the increment of conveying pressure difference, the individual particles increase and the particle clusters decrease, the individual particle distribution is always inhomogeneous but the particle cluster distribution tends to be more homogeneous over the cross-section of pipe, while the average flow behavior of pulverized coal particles is always in the relatively static state. For unsteady flow, the average flow behavior of pulverized coal particles is dynamic, and the flow behaviors of the multi-scale flow structures over the cross-section of pipe are all significantly inhomogeneous. Moreover, the effect of particle size on flow behavior of pulverized coal is also investigated and validated.     

An experimental study of relative humidity and air flow effects on positive and negative corona discharges in a corona-needle charger

In this paper, the effects of inlet air RH and air flow rate on positive and negative corona discharges in a corona-needle charger have been experimentally studied and discussed. Its corona discharge characterizations in terms of current-to-voltage relationships of the corona-needle charger on the effects of inlet air RH and air flow rate were evaluated at applied corona voltages between 0 and 3.1 kV, an air flow rates between 5 and 15 L/min, a relative humidity between 20 and 90%, and an operating pressure of about 101.3 kPa. Experimental results were shown that discharge current is strongly affected by the RH level of the inlet air. The positive discharge current was found to be decreased with increasing RH value at RH values below 60% and increased with increasing RH value at RH value above 60% in the same corona voltage. The negative discharge current was found to be stable with increasing RH value at RH values below 40% and increased with increasing RH value at RH value above 40% in the same corona voltage. For the air flow rate effects, the positive discharge current was found to slightly decrease when the air flow rate increased at RH value below 90% and to increase with the air flow rate at RH value of 90%. For the negative corona, the discharge current was also found to monotonically decrease when the air flow rate increased.     

充电系统可靠性分析

本文给出了充电系统一次及k次充电可靠性的计算表达式;并利用R软件模拟系统的实际充电过程,验证给出的计算表达式的准确性,为实际应用提供理论依据。     

Effects of ion-pairing on rate of electron transfer between immobilized gold nanoclusters and soluble redox probes

Hydrophilic gold nanoclusters were tethered onto gold electrodes modified with mixed 1-octane thiol/1,9-nonane dithiol monolayers. The heterogeneous electron transfer (ET) kinetics of soluble redox species in the supporting electrolyte were investigated at these electrodes by cyclic voltammetry (CV) in the presence and absence of the ion-pairing anions and . The redox species investigated, [Fe(CN)₆]^3−/4− and [Co(C₁₂H₈N₂)₃]^3+/2+ where oppositely charged. The results presented here reveal that the rate of ET for the negatively charged redox species decreases with decreasing ionic charging time constant of the electrolyte. The opposite trend is observed for the positively charged redox species.     

MH电极中氢扩散系数的测定及其应用

利用恒流放电法测定了金属氢化物(MH)电极中氢原子扩散系数的平均值. 通过恒电位法测定了MH电极中氢原子的扩散系数与其荷电态(SOC)的关系. 根据MH电极模型可知, 增大氢原子扩散系数或减小储氢合金粒径均能提高MH电极的快速充电性能, 并能计算出MH电极在不同的初始荷电态、不同充电倍率下, 表面氢原子浓度达到最大值所需的时间.     

The Variation of Composition of Resols Under Different Reaction Conditions

The multi-hydroxymethyl structure of resol makes it suitable for connecting two or more polyacrylamide chains as a crosslinker in oil recovery applications, but control of the structure and composition of the resol, whether in practice or theory, is still a controversial problem. In the present research, a series of resol prepolymers synthesized with different amounts and types of catalysts, formaldehyde to phenol molar ratio, reaction temperature and charging steps were characterized by high-performance liquid chromatography. It is found that the compositions of the resols barely changed with almost all the varying conditions, but the contents of each component were greatly affected by the variation of reaction conditions. Finally, the best conditions for preparing resol crosslinker were obtained.     

低电压扫描电子显微术

低电压扫描电子显微术是研究半导体、绝缘体和生物材料的有效方法。本文综述了这种方法的优点、限制和关于扫描电镜的改进,并且提供了实际操作的某些要领。     

电动车用动力铅酸蓄电池的研究进展

简要介绍了电动车用铅酸动力电池的发展情况,包括了电池板栅的合金选择及板栅设计、正负极板铅膏的配方、电解液配方、隔板材料和充电方式等方面的改进,提出了今后电动车用铅酸蓄电池的研究发展方向。