共查询到19条相似文献,搜索用时 312 毫秒
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《中国无线电电子学文摘》2005,(1)
0463 2005010061流状电极结构对大气压表面放电的影响/张锐,汪磊,徐蕾,程诚,詹如娟(中国科技大学)11真空科学与技术学报一2004,24(3)一216一218研究了梳状电极结构对大气压表面放电的影响,发现频率固定时放电电流随着外加电压的增加而增加,而电压固定时在某个颇率范围内放电电流有最大值;在相同的电压和频率下较宽的电极条宽可以产生较大的放电电流,而电极条间距又们玫电电流几乎没有影响;用整块金属板做接地电极相比于梳状接地电极可以产生较大的放电电流;另外,较厚的电压电极可以在介质板表面产生更明亮、厚度更大的放电等离子体.图5参5(… 相似文献
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采用四层端电极(Ni/Cu/Ni/Sn)结构设计,底层为Ni,电镀Cu/Ni/Sn的工艺方法,制作了大容量MLCC。研究了四层结构和三层结构(Cu/Ni/Sn)对电容量等基本电性能、可靠性和内应力的影响。结果表明:制作1206规格10μFMLCC,C为9.86~10.46μF、tanδ为(360~390)×10–4、绝缘电阻≥1.5×108Ω、耐电压值为175~205V,四层结构与三层结构电性能相当。可靠性测试中,四层结构抗机械和热冲击能力提高了20%,且有利于瓷体内应力释放。 相似文献
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Jemaa N.B. Doublet L. Morin L. Jeannot D. 《Components and Packaging Technologies, IEEE Transactions on》2002,25(3):420-426
In order to fulfil the increasing need for electric power in automobiles, to satisfy the new environmental requirements and to decrease the weight of cars, the electrical supply, must be changed from the current 14 V to 42 V. In the present work using 42 V, we have studied arc parameters such as break arc duration and extinction gap for different materials, contact opening speeds and circuit loads (correlated with the time constant of the circuit, L/R). We have established that these main arc parameters are greatly enhanced compared to the 14 V arc studied in our previous work. In the case of an inductive or a resistive load, it has been found that there are two domains: a low current domain where the material has no significant effect, and a high current domain where some materials (primarily AgSnO/sub 2/) induce high arc durations and large extinction gap. In addition, increasing the opening speed reduces arc duration in all cases. The increased opening speed can however, increase the extinction gap for inductive loads and decrease it for resistive circuits. We have found that reducing arc duration is always beneficial with regards to erosion but in some cases, however it may increase the extinction gap. 相似文献
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为了解决功率器件高击穿电压与减小表面最大电场需求之间的矛盾,提出了一种高压功率器件终端场板改进方法。通过调节金属场板和多晶硅场板的长度,使金属场板覆盖住多晶硅场板,最终使得两者的场强相互削弱,从而减小表面最大电场。采用TCAD(ISE)软件对该结构进行仿真验证,结果表明该结构能够在保证高耐压的前提下减小表面最大电场。基于所提方法,设计出了一种七个场限环的VDMOSFET终端结构,其耐压达到了893.4 V,表面最大电场强度只有2.16×105 V/cm,提高了终端的可靠性。 相似文献
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对采用阳极氧化法及阴极还原表面处理技术制备的性能稳定的纳米多孔硅,用原子力显微镜(AFM)表征了其微观结构,多孔硅颗粒粒径在30 nm左右.室温条件下测试了多孔硅场电子发射的特性,结果表明,多孔硅具有很好的场致发光性能,在5 V/μm的电场下就可以产生场发射电流.多孔硅的开启电压在1 000 V左右,发射电流随着电压的增大而不断增大,发射电压在2 000 V以上.Abstract: Nanoscale porous silicon (PS) was prepared by anodic oxidation, cathode reduction and surface treatment technique. The porous silicon particles with the average diameter of about 30 nm were obtained by characterizing their microstructure with atomic force microscope (AFM). Electron field emission characteristics of porous silicon were investigated at room temperature. The resuhs demonstrate that porous silicon has favorable electroluminescence properties, and the field emission current can be generated only under the electric field of 5 V/ μm. And the turn - on voltage is about 1 000 V. With the increase of the offered voltage, the emission current is enhanced and the emission voltage is over 2 000 V. 相似文献
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激光-熔化极脉冲电弧复合焊接的双重导电机制 总被引:3,自引:0,他引:3
对激光-电弧复合焊接的稳弧机理始终存在不同的观点。通过高速摄像机和光谱分析仪对比研究了激光与电弧复合前后电弧形态发生的变化。研究发现复合后电弧呈现一种全新的形态,具有两个独立的导电通道,这种现象被称为"双重导电机制"。这种机制对维持电弧稳定和保证焊缝成型良好具有非常重要的意义,正是激光-电弧复合焊接高速焊接过程中稳弧的关键所在。研究还发现"双重导电机制"的建立过程存在时间顺序,辅助导电通道首先是从激光小孔周围建立起来,然后逐渐扩展到整个电弧区域。各种焊接参数对"双重导电机制"也存在明显的影响。 相似文献
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GAT实现高频率与高基区穿通电压兼容特性分析 总被引:1,自引:1,他引:0
通过作者最近建立的关于 GAT器件集电结耗尽层电位分布和电场分布的二维解析模型 ,定量研究了 GAT的基区穿通电压 VPI,并且解释了该器件实现高频率与高电压兼容的实验结果。 相似文献