高频激励横流CO2激光器的实验研究

本文在实验上在气压为120mba、100mba和80mba,气压比为CO2:N2:Ar=7:46.5;46.5,间隙为20mm,26mm和27mm,电极直径为12mm、长为700mm的情况下,对网络的高频传输特性,间隙高频放电的伏安特性及激光功率输出特性进行了一定的研究,在国内首次得到高频激励横流CO2激光器400W的激光输出.注入功率密度达20W/cm3,与相同条件下的直流针板式激光器相比最大注入功率提高了约一倍,最大电光转换效率为9%.     

基于IWC系统的功率型LED散热研究

针对功率型LED芯片现有散热方案的缺陷,设计了一种“针-网”式离子风散热（Ionic wind cooling,IWC）系统。并通过试验对不同曲率半径、分布密度的针电极结构以及不同电晕放电控制方式下IWC系统作用于功率型LED的散热性能进行了测试。采用红外热像仪测得了离子风对于发热体强化传热作用下的系统温度分布。结果表明：IWC系统的散热效果显著,针电极曲率半径为80 μm、针电极间距为7.5mm时,散热效果最佳;电晕功率为3W时,IWC系统能在较短时间内降低LED芯片引脚温度。     

电子枪及其制造方法

是在以前结构的电子枪中，仅有数根芯柱管针支持着固定辅助件和电极的支架玻杆等的结构，由于支持的芯柱管针的根数左右侧不一样，一旦在电子枪制作后，在芯柱管针上加力，会塑性变形，那么，电子枪整体就产生倾斜与扭曲变形，因此，芯柱管针少的一侧易变形等。     

无电极放电灯的新进展

无电极放电灯是新型放电灯，由于没有电极，使该煤具有结构简单、高显色性、高光效和长寿命等特性，近年来对灯的进一步开发使灯应用更加广泛，无电极放电煤将发展成为21世纪新的节能光源。本文主要介绍了无电极放电灯的种类、特性和新的进展。     

电极结构对于大气压低温等离子体射流初始电场的影响——创新信息论坛优秀论文

为研究不同电极结构对于大气压低温等离子体射流电场的影响,建立了二维轴对称模型,利用COMSOL软件对三种不同的电极设置情况进行了仿真。仿真结果表明,只有针电极时,电场强度比较低,壁上加环电极时,最大电场强度显著增大,且环电极的宽度对它的大小也有影响,壁外加环电极时,最大电场强度也增大,但增加的幅度较环电极在壁上时小,且随着环电极距壁的距离越来越大,产生的影响也越来越小。     

板式水冷冷凝器在进口大功率发射机上的应用

本文分析了板式水冷冷凝器与风冷式冷凝器在性能、运行及能量消耗上的差别,对TSW2500型进口发射机中的风冷式冷凝器进行改造,选用新型板式冷凝器进行热交换,经实际使用取得了良好的冷却效果。     

PZT铁电薄膜离子束刻蚀研究

以Ｐｔ为上下电极和中间ＰＺＴ薄膜的铁电电容器主要由油射法和离子束刻蚀法制备。研究快速热处理实现铁电相转变的条件和离子束刻蚀工艺对铁电容器图形的影响，选择合理的制备工艺可得到针电电容器。     

未来型电池──氧化锂─锰充电电池

未来型电池──氧化锂─锰充电电池美国贝尔通讯研究所（Ｂｅｌｌｃｏｒｅ）（简称贝尔可）的化学家最近发明了一种新型１Ｌｉ－Ｍｏ－Ｏ可充电电池，它在氧化锂─锰电极和碳电极间加入锂离子梭动装置。目前，这种新型电池仍处在实验阶段。据称，它将比其它锂离子电池更加...     

高功率横流CO2激光器的新型管板式电极

提出一种更适用于焊接等场合的低阶模输出的新型管板式电极。阳极块长边沿阴极管方向,提高了放电均匀性和稳定性,增加了有效放电长度;阳极沿气流方向的长度和阴阳两极之间的距离根据输出模式确定,可充分利用激活体积,提高选模激光光电转换效率;其放电均匀稳定,可减小限流电阻值,降低外电路电功损耗。与现有管板电极相比,可提高注入到激活体积内的电功率密度,明显提高选模激光输出功率和总体效率。多模输出时直接光电转换效率可达20%;低阶模TEM11输出时光电转换效率可达15%,激光器总效率达8%。该电极结构适用于国内生产的横流CO2激光器,在不同模式输出时均能获得较高的光电转换效率,从而使其更好地应用于焊接等低阶模输出场合。     

用于新型荧光字符平板显示器的银浆料

针对新型荧光字符平板显示器件的工艺特点，研制出了能满足其工艺要求的电极银浆料。该浆料的最佳峰值烧成温度为５５０～５８０℃，玻璃相含量５．５％～６．５％（质量分数）。用它制作的电极具有阻值低、附着力强、分辨率高等优点，可替代进口的同类浆料。     

Development and Testing of a 2-D Transfer CCD

This paper describes the development, operation, and characterization of charge-coupled devices (CCDs) that feature an electrode structure that allows the transfer of charge both horizontally and vertically through the image area. Such devices have been termed two-dimensional (2-D) transfer CCDs (2DT CCDs), as opposed to the conventional devices, which might be called one-dimensional transfer CCDs, but in other respects are the same as conventional CCD devices. Batches of two different 2DT CCD test devices, featuring different electrode structures but with identical clocking operation in each case, were produced and tested. The methodology of 2-D charge transfer in each of the device types is described, followed by a presentation of test results from the new CCDs. The ability of both 2DT CCD transfer electrode schemes to successfully transfer charge in both horizontal and vertical directions in the image section of the devices has been proven, opening up potential new applications for 2DT CCD use     

高功率横流CO2激光器的锥面反射镜谐振腔

根据针-板放电5kW横流CO2激光器的结构特点,设计并实验研究了直角锥面镜作为全反射镜的谐振腔。在菲涅耳-基尔霍夫理论的基础上,引入柯林斯公式并考虑增益影响,推导了锥面谐振腔的衍射积分方程,并进行了相应的模拟计算。研究结果表明,在高功率横流CO2激光器中锥面反射镜与平面输出镜相配合使用组成稳定腔,获得了TEM30的低阶模输出;由于锥面反射镜受加工精度的影响中心残留有加工盲孔,导致TEMmn(m=0,n≠0)的模损耗较大不易耦合输出;而镜面中心场分布很弱的其他低阶模因损耗小,则会优先输出。     

新型Rogowski电极的设计及分析

提出了一种适用于大功率TEA CO2气体激光器的新型Rogowski电极横截面设计方法,经过构造和分析这种截面后,对这种截面进行了比较和电场的分析,并对这种截面的参数设计提出了参考性建议.结果证明,此设计给大体积横向放电激光器的电极截面的选择提供了一种新的途径.     

Carbon Fiber as an Electrode Material

A new type of carbon electrode is introduced. The electrode consists of a bundle of carbon fibers, each fiber having a diameter of approximately 8 jim. In contrast to most electrodes, this electrode is flexible. The fabrication of the electrode is described, and a method is given to determine the apparent stimulating area.     

Electrical impedance tomography

Electrical impedance tomography (EIT) is an imaging modality that estimates the electrical properties at the interior of an object from measurements made on its surface. Typically, currents are injected into the object through electrodes placed on its surface, and the resulting electrode voltages are measured. An appropriate set of current patterns, with each pattern specifying the value of the current for each electrode, is applied to the object, and a reconstruction algorithm uses knowledge of the applied current patterns and the measured electrode voltages to solve the inverse problem, computing the electrical conductivity and permittivity distributions in the object. This article focuses on the type of EIT called adaptive current tomography (ACT) in which currents are applied simultaneously to all the electrodes. A number of current patterns are applied, where each pattern defines the current for each electrode, and the subsequent electrode voltages are measured to generate the data required for image reconstruction. A ring of electrodes may be placed in a single plane around the object, to define a two-dimensional problem, or in several layers of such rings, to define a three-dimensional problem. The reconstruction problem is described and two algorithms are discussed, a one-step, two-dimensional (2-D) Newton-Raphson algorithm and a one-step, full three-dimensional (3-D) reconstructor. Results from experimental data are presented which illustrate the performance of the algorithms     

Self-shift plasma display panels with meander electrodes or meander channels

Two new types of self-shift plasma display panels with meander electrodes (ME-PDP's) and with meander channels (MC-PDP's) are described, both of which have new electrode configurations characterized by interdigital pairs of electrodes on each substrate. The panels have simple structures which do not require electrode crossovers, and therefore have good potentials for low cost compared with our former type of panel. Principles and characteristics of the two new types are discussed, and comparison between them leads to the conclusion that the ME-PDP, which can eliminate even the barrier structure by adopting meander electrode patterns, is superior for a high-resolution display.     

旋流二氧化碳激光器腔内增益分布的改进

常用的工业二氧化碳激光器,主要为横流、纵流和扩散冷却三种.文章对作者提出的新型旋流二氧化碳激光器进行了简要介绍,重点研究了腔单元结构和电极结构变化对腔内增益分布状态的改进.依托该研究结果,发展出新型转流二氧化碳激光器实验样机,实现了基模700W输出,并进行了板材样品的精密切割实验.     

A Computer-Controlled Stereotaxic System

The stereotaxic technique serves as an invaluable tool for the reliable and accurate placement of electrodes in living brain tissue. By placing the stereotaxic device under computer control an entirely new set of operational procedures is established which enhances and enriches the basic capabilities of the stereotaxic technique. The system consists of a number of basic programs which provide for positioning of the electrode, executing the particular experiment and reviewing the data. Programs are available which allow the experimenter to position the electrode at coordinates typed in via an on-line keyboard. One program allows the investigator to specify multiple points at once. The operator merely fills in a simple format displayed on the oscilloscope that defines the geometry of the electrode path. These geometries include points, lines, planes, and volumes. The system successively positions the electrode at all points explicitly and implicitly specified by the format and, at each intermediate point, executes the experimenter's specially written program. The computer presents a display to the investigator after executing his program (for example for stimulating and storing the resultant averaged evoked potentials) at each of those points. A comment may be entered by the experimenter that remains a permanent part of the data set (electrode position-comment-evoked potentials) stored on tape. The data sets may be recalled for review at anytime.     

Determination of Oxygen Tension by Measurement of Net Charge Transport

Conventional electrodes that are used to measure oxygen tension in the biological environment have been plagued by one or more of three major problems: 1) flow sensitivity, 2) instability, and 3) inadequate response time. Pulsatile operation of the electrode has the potential of eliminating these problems. A new technique of measurement using integration of output current has been developed. This new method of measurement enhances the pulsatile operation in the Po2 electrode. The technique effectively determines the difference in charge transport that occurs during the polarization potential. Using this technique, it has been possible to measure net charge transport, which is proportional to the oxygen tension level of whole blood as early as 1 ms after application of the polarization pulse. Also, the subtraction of the discharging current component appears to stabilize electrode drift. The short polarization time required allows for the elimination of flow sensitivity by reducing the extension of the oxygen diffusion gradient to less than 8 ?m from the electrode face. The short duration of active measurement will tend to decrease poisoning by allowing use of an operating duty cycle of minimal duration.     

The "Hourglass" energy diverter

A new design for a series spark-gap array for energy diverter usage has been developed. The electrical circuit of this array differs from previously reported energy diverter designs in two respects. First, the capacitors from each electrode to ground are eliminated, and second, the interelectrode capacitances of the gaps are not all equal. By varying the interelectrode capacitances of each gap in accordance with predetermined requirements, it was possible to study several triggering modes. In particular, two triggering modes were investigated; a "constant overvoltage" mode and an "increasing overvoltage" mode.