用于钠泵的螺管型超导磁体设计与实验

本文对钠金属电磁泵的螺管型超导磁体部分进行了详细设计和实验研究.磁体设计指标为水平室温孔长度600mm,直径160mm,中心场磁感应强度5T.对超导磁体所用的超导线进行了短样测试,当温度为4.2K、磁感应强度为5T时,临界电流为464A,大于工作电流.磁体经过绕制、真空压力浸渍工艺后进行10次失超锻炼,在失超电流97 A的电流下测试,磁体中心磁感应强度达到4.66T.若进一步降低励磁速率,磁体中心磁感应强度预计可以达到5T左右,可以满足钠金属电磁泵的要求.     

非无线电设备的无线电波辐射

介绍了电磁辐射的分类和非无线电辐射造成的各种危害，指出了可能产生电磁辐射的设备，给出了几种特殊情况的辐射值，并结合国际标准和国家标准，分析了电磁干扰的管理现状，最后提出了减少非无线电设备电磁辐的几种方法。     

精密有源互感器的研制

本文介绍了精密有源电流互感器的原理和设计方法。该互感器的准确度达到０．０１级，线性度优于１×１０－５．     

变压器绝缘电阻低于允许值的处理

本文就一台主变压器绝缘电阻低于“规程”允许值的问题，进行了原因分析，提出了简易的处理方法，取得了较好效果，同时提出了几个值得探讨的问题，对提高变压器的安全运行水平有一定的现实意义。     

俄罗斯第三代电磁探伤仪的应用与推广

在油水井生产过程中,由于周围环境的影响,套管发生变形、损坏和腐蚀,直接影响油田的正常生产。多层管柱电磁探伤测井技术利用电磁感应原理实现对井下多层管柱的腐蚀、变形、裂缝及壁厚进行检测。介绍俄罗斯最新产的电磁探伤测井仪MID-K的原理方法、仪器结构及特点,并用测井资料展示其在单套管和多层管内进行套管检查中良好的应用效果。     

Series resonant ZCS‐PFM DC‐DC power converter with high‐frequency high‐voltage transformer link for high‐power magnetron drive

This paper presents a single lossless inductive snubber‐assisted ZCS‐PFM series resonant DC‐DC power converter with a high‐frequency high‐voltage transformer link for industrial‐use high‐power magnetron drive. The current flowing through the active power switches rises gradually at a turned‐on transient state with the aid of a single lossless snubber inductor, and ZCS turn‐on commutation based on overlapping current can be achieved via the wide range pulse frequency modulation control scheme. The high‐frequency high‐voltage transformer primary side resonant current always becomes continuous operation mode, by electromagnetic loose coupling design of the high‐frequency high‐voltage transformer and the magnetizing inductance of the high‐frequency high‐voltage transformer. As a result, this high‐voltage power converter circuit for the magnetron can achieve a complete zero current soft switching under the condition of broad width gate voltage signals. Furthermore, this high‐voltage DC‐DC power converter circuit can regulate the output power from zero to full over audible frequency range via the two resonant frequency circuit design. Its operating performances are evaluated and discussed on the basis of the power loss analysis simulation and the experimental results from a practical point of view. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(3): 79–87, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20126     

Electronic Emissions Security: Danger in the Air

Most organizations have measures to protect their network infrastructure from intruders. With the growth AND AVAILABILITY of wireless, some intruders now are aiming their attacks there. The potential for damage from these types of attacks is significant due to their nature. However, there is another type of wireless attack on organizational resources that also poses a significant vulnerability. That is electromagnetic radiation, also called radio frequency emissions (RFE), from unprotected systems and networks.     

铝合金电磁铸造工艺参数的研究

通过近似计算和试验确定了工程规模的铝合金电磁铸造（ＥＭＣ）基本工艺参数如感应器电流、电压、频率、功能消耗等一液柱高度及稳定性的关系，设计制造了ＥＭＣ装置，成功地铸造了截面直径为０．１８ｍ，０．１１×０．０５ｍ，０．５２×０．１３ｍ的铝及铝合金锭和扁锭。     

电话通信设备电磁干扰的测量分析

本文探讨了ＴＥＭ室测量电话通信设备辐射干扰的原理、方法，得出了在线电话终端０．１５～３０ＭＨｚ频段辐射干扰测量结果，并进行了分析。     

再论变化电磁场中带电超微粒子的精确量子论

利用创新的SU(1 ,1 )Lie代数理论及SO(3)Lie代数理论 ,得到变化电磁场中带电超微粒子的精确量子论 ,由此进一步明确微观领域中的时空概念