Three‐dimensional numerical analysis on discharge properties of microwave excited ring dielectric line surface wave processing plasma device

A three‐dimensional simulation code with the finite difference time domain (FDTD) method combined with the electron fluid model has been developed for the microwave excited surface wave plasma in the RDL‐SWP device. This code permits the three‐dimensional numerical analysis of the spatial distributions of electric field, power absorption, electron density, and electron temperature. At a low gas pressure (about 10 mTorr), the numerical results were compared with the experimental measurements that show the validity of this 3D simulation code. A simplified analysis assuming that the electron density is spatially uniform has also been studied and its applicability is evaluated by the comparison of the 3D simulation and the analytical solutions. The surface wave eigenmodes are determined by the electron density, and it is found that the structure of the device strongly influences the spatial distribution of the electric fields of surface waves in a low‐density area (n_e < 3.0 × 10¹¹ cm^?3). A method to irradiate by microwave the whole surface area of the plasma is proposed. The method is found to be effective in obtaining a high uniformity distribution of electron density. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 150(4): 1–12, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10333     

DSP在变频电源下的电动轮自卸车控制中的应用

介绍了154吨电动轮自卸车的电气原理,简要说明了以TMS320F2812为核心的控制系统对154吨电动轮自卸车的控制过程,重点讨论了TMS320F2812如何通过硬件检测到有效的同步信号,并利用软件产生同步移相触发信号,最终将控制量转换为同步移相触发信号的输出,以实现对154吨电动轮自卸车进行励磁调速的过程。试验结果表明,该控制方案有效消除了变频电源对154吨电动轮自卸车控制的影响。     

水轮机流量测量数据的数值逼近方法研究

结合石家庄混合蓄能水电站3号机组能量试验的实际结果,针对目前水轮机流量与蜗壳压差关系表达式计算精度低的缺点,提出了逼近水轮机流量测量数据的新的数值方法。并给出了新的水轮机流量与蜗壳压差关系表达式,同时也给出了详细的逼近计算过程和计算公式。通过实例表明,给出的新的关系表达式,具有逼近计算精度高的特点,可以更好地应用于水轮机的实际运行中。     

地震子波频率浅析

地震子波频率概念的合理选择与准确应用对于地震采集设计、地震模拟研究、地震资料处理、地震属性分析以及质量评价等是非常重要的.针对目前地震子波频率由于定义方式出现的各种概念（视频率、主频、峰值频率、中心频率等）以及理解上出现的偏差等问题,首先从时间域定义和频率域定义2个方面进行了归纳和总结,并在此基础上对3种常用地震子波（Ricker子波,Zinc子波,正弦指数衰减子波）进行了分析和研究,得出视频率与主频概念一致,但不同地震子波的峰值频率、中心频率和视频率（或主频）之间并不完全一致的结论;而对于实际地震资料,将峰值频率近似看作地震子波的主频是可以的,但在地震子波已知的情形下这样做是不恰当的,甚至可能会得出错误的结论和认识.     

Perception of Visual Speed While Moving.

During self-motion, the world normally appears stationary. In part, this may be due to reductions in visual motion signals during self-motion. In 8 experiments, the authors used magnitude estimation to characterize changes in visual speed perception as a result of biomechanical self-motion alone (treadmill walking), physical translation alone (passive transport), and both biomechanical self-motion and physical translation together (walking). Their results show that each factor alone produces subtractive reductions in visual speed but that subtraction is greatest with both factors together, approximating the sum of the 2 separately. The similarity of results for biomechanical and passive self-motion support H. B. Barlow's (1990) inhibition theory of sensory correlation as a mechanism for implementing H. Wallach's (1987) compensation for self-motion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

介质阻挡放电与脉冲电晕放电净化气态污染物的试验研究

利用自行研制的介质阻挡及脉冲电晕放电低温等离子体发生器对空气中氨、硫化氢、甲苯等5种气态污染物进行净化，并探讨了两种放电方式的原理和特点。试验结果表明：与介质阻挡放电相比，脉冲电晕放电具有更好的净化效果。     

The gas film in spark assisted chemical engraving (SACE)—A key element for micro-machining applications

Machining of various electrically non-conductive materials is possible with Spark Assisted Chemical Engraving (SACE). Even though this technology presents several interesting properties like simplicity, flexibility and the possibility to obtain very smooth machined surfaces, it has one severe weakness: reproducible machining can hardly be achieved. One of the main limiting factors is the unstable gas film around the tool electrode in which the necessary electrical discharges for machining take place. The known facts about this gas film are reviewed and a theoretical model allowing an estimation of its thickness is derived. An experimental method for measuring this thickness using the inspection of the current–voltage characteristics of the process is presented. Several methods to obtain more reproducible machining are proposed. It is demonstrated that decreasing the gas film thickness by changing the wettability of the tool electrode can result in significantly higher machining repeatability.     

某黄金冶炼厂含氰污水"零排放"生产实践

介绍了某黄金冶炼厂通过对洗涤工艺流程的改造，实现了合氰污水零排放。通过采取新型设备、新工艺流程等措施实现各种污水全循环，减少氰化污水排放量。通过该厂的生产实践证明污水“零排放”是环保治理的有效途径。     

双电层电容器高比表面积活性炭的研究

以石油焦为原料,KOH和NaOH为活化剂制取双电层电容器用高比表面积活性炭电极材料。考察了活化剂的种类及其与石油焦配比对活性炭比电容的影响,并对KOH和NaOH的混和物在活化过程中金属K和Na的协同作用进行了初步探讨。研究结果表明控制适宜的活化工艺条件可制得比电容高达52.60 F/g的高比表面积活性炭,用它组装成的双电层电容器具有良好的充放电性能。     

水闸大孔口淹没堰流泄流能力的探讨

根据牛顿阻力公式和能量方程，初步研究了胸墙流速系数和大孔口淹没堰流流量的计算方法，所得结果得到水槽模型试验资料的检验，并与按孔流方法计算的结果做了比较，获得一些有益的认识．