我国《电磁辐射防护规定》开始编制

人们对电磁辐射并不陌生,它的应用已深入到人类生活的各个方面,如通讯、无线电及电视广播、高频淬火及医疗上对癌症进行治疗等等。象许多其他事物一样,电磁辐射也具有两重性,一方面可为人类造福,改善人们的生活条件,另—方面对人的机体有损伤作用。常用频段的电磁辐射能量较低,虽不会象x或y射线那样会使物质电离,使人产生电离损伤,但若电磁辐射能量在人体内大量沉积,也会使机体明显出现损伤,例如,引起白内障、热调节失调及热损伤等。电磁辐射能量即使在人体内沉积不多,没有明显地升温现象,仍可能产生类似神经农弱一样的症候群。此外,在大功率电磁辐射设备邻近区域,电视收看效果受到影响,会使计算机失误,会影响心脏起搏器的正常工作等。大量的电磁辐射能在环境中构成了影响人们生活的新污染源。     

电磁辐射的生物学效应

简要介绍了电磁辐射生物学效应机制的几种研究理论,从整体生物效应、细胞效应,以及电磁辐射对基因表达和对肿瘤形成的影响等方面总结了近年来电磁辐射生物学效应的研究成果,并对今后的研究工作提出了几点个人看法.     

地铁高频电磁辐射的安全评估

为有效评估B型地铁乘客信息系统天线(Passenger information system,PIS)对司机室高频电磁辐射的安全性,设计PIS系统所用的5.8 GHz八木天线和司机人体模型,利用三维电磁仿真软件构建在PIS系统天线辐射下的地铁司机室高频电磁环境模型,数值模拟天线在不同输入功率条件下对地铁司机人体模型的高频电磁辐射影响。仿真结果表明,当天线的输入功率达到最大值50 W时,人体模型的比吸收率最大值0.63 W/kg,低于国际非电离辐射委员会(International Commission on Non-Ionizing Radiation Protection,ICNIRP)制定的职业电磁暴露基本限值10 W/kg;电场强度最大值为72.37 V/m,低于ICNIRP职业电磁暴露参考限值137 V/m;磁场强度最大值为0.74 A/m,高于ICNIRP职业电磁暴露参考限值0.36 A/m。当天线的输入功率降为10 W时,磁场强度最大值降为0.33 A/m,低于参考限值。因此,为了避免此高频电磁辐射对司机造成健康危害,地铁实际运行时,需要保证天线的输入功率低于10 W,使司机处于安全辐射范围内。     

射频辐射对健康影响的流行病学调查

从人体心血管系统、生殖系统、免疫系统以及主观症状、激素产生、听觉和前庭系统方面，介绍了射频电磁辐射对健康影响的流行病学调查现状，并对今后的研究工作提出建议。     

输变电设施电磁辐射环境影响评价方法探讨

结合输变电设施周围电磁环境特点,对其电磁辐射环境影响评价方法进行探讨,提出相应的电磁辐射污染防治措施与建议,消除公众疑虑。在此基础上,总结当前电磁辐射环评工作中存在的问题,以期为后续同类问题深入研究提供思路。     

移动通信基站电磁辐射环境监测布点的讨论

依据国家有关电磁辐射环境监测标准，从移动通信基站天线向周围辐射电磁波的特点出发，考虑基站天线电磁辐射的主瓣、副瓣和盲区三种情况，对移动通信基站周围电磁辐射环境监测的范围、布点方式和点位确定进行了讨论。     

电磁辐射固定点监测布点方案

简要介绍了电磁辐射固定点监测的内容、作用、特点和发展趋势，分析讨论了电磁辐射固定点监测不同布点方案的适用场合及使用方法。     

强流离子源电参数测量系统的电磁兼容设计

为保证强电磁干扰环境下测量系统的正常工作,对基于虚拟仪器的离子源远程电参数测量系统进行了电磁兼容性设计。从电源供电回路、测控信号输入输出通道、通讯网络、接地及屏蔽等方面研究了有关的电磁兼容性问题,并针对调试中的问题改进了设计。现场试验表明,该设计可以有效减少经由共阻抗耦合、供电电源耦合以及空间电磁辐射耦合途径传输的电磁干扰,远程数据采集系统工作正常。     

日常生活的电磁辐射与生物效应

本文简单介绍了电磁辐射和生物效应的原理和现象以及相关的研究情况和标准.包括:电磁辐射对机体的影响,电磁辐射对人体影响的研究情况,行业的卫生标准和生活中与电磁辐射接触的机会.     

岭澳核电站灯具更换的电磁兼容性研究

目前岭澳一期核电站主控室采用的电感灯将逐步被三星LED灯替代,但三星LED灯配置的开关电源产生的电磁辐射可能影响其他核电设备的正常工作,带来电磁兼容性问题。论文首先根据文献调研情况提出了主控室内设备设施的辐射抗扰度水平,然后从试验和现场实测两个角度,对三星LED灯和电感灯的电磁辐射骚扰特性进行了分析;同时在试验室对上述两种类型灯具的低频传导骚扰电压和谐波电流进行了对比测试。结果表明:从电磁辐射骚扰水平大小来看,考虑最严重条件下,主控室更换为三星LED灯后,产生的电场辐射骚扰水平和低频磁场辐射骚扰水平均远小于前述提出的核电设备辐射抗扰度水平,低频传导骚扰电压和谐波电流测试结果也满足现有国家标准要求,因此三星LED灯可替换目前主控室照明的电感灯。     

有源光纤EMP测量系统及对EMP模拟器空间场测量

介绍一种利用光纤传输的强电场探测器，它很好地解决了强电磁场环境下，电磁干扰对测试系统的影响，具有输入阻抗高、频带宽、抗干扰能力强的特点。     

Probe method to measure the electromagnetic field in a plasma by Poynting vector conversion

In this paper,a high-precision electromagnetic measurement system suitable for a high-temperature and high-speed plasma is built to provide a platform for scientific research on the interaction mechanism of the electromagnetic fields and a plasma.This paper presents a method to measure the electromagnetic field inside a plasma by using a probe and Poynting vector conversion,which is a new and completely different method from the traditional method of measuring the electromagnetic field inside plasma.In addition,for this system and method,this work designs a microstrip antenna probe that can suppress multipath effects.This method is confirmed to be valid and usable after closed-loop verification by the CST software.     

Research on a Folded Blumlein Line Using Kapton Film as Dielectrics

In this project, a Blumlein line with a folded parallel-plates configuration using Kapton film as dielectrics was investigated. The characteristic parameters of this Blumlein line were analysed theoretically. The electric field distributions under different inner radii of the folded part were simulated. The output waveforms on the match load were also simulated by means of an equivalent electric circuit. According to the results of the theoretecal analysis and simulation, a Blumlein line with the folded parallel-plates configuration with an output voltage of 500 kV, a pulse duration of 100 ns, and a characteristic impedance of 4.773Ω was designed and manufactured. The experimental results properly demonstrated the wave transmitting process in the Blumlein line, and provided the voltage waveform of 500 kV and the current waveform of 50 kA with a pulse duration of 150 ns. Some engineering problems such as the edge electric breakdown and measuring precision by a resistance divider were revealed, which must be solved in future work to produce a more compact transmission line.     

中国先进研究堆安全棒驱动机构改进设计

分析了中国先进研究堆（CARR）在C阶段调试过程中发生的安全棒意外落棒事件,查找原因为：安全棒驱动机构回路中电磁阀因长时间工作引发烧损失效,为解决该安全隐患,对CARR安全棒驱动机构进行改进设计,提出“水力提升-水力磁力保持式”安全棒驱动机构设计方案,使用Ansoft公司的有限元分析软件Maxwell对水力提升-水力磁力保持式安全棒驱动机构磁路进行有限元分析,计算得到驱动机构的电磁场分布及电磁力的数值,计算结果表明,磁力保持装置产生电磁力可达到安全棒驱动线重量的2.12倍,具有一定的裕度。     

Discovering exact,gauge-invariant,local energy-momentum conservation laws for the electromagnetic gyrokinetic system by high-order field theory on heterogeneous manifolds

Gyrokinetic theory is arguably the most important tool for numerical studies of trarnsport physics in magnetized plasmas.However,exact local energy-momentum conservation laws for the electromagnetic gyrokinetic system have not been found despite continuous effort.Without such local conservation laws,energy and momentum can be instantaneously transported across spacetime,which is unphysical and casts doubt on the validity of numerical simulations based on the gyrokinetic theory.The standard Noether procedure for deriving conservation laws from corresponding symmetries does not apply to gyrokinetic systems because the gyrocenters and electromagnetic field reside on different manifolds.To overcome this difficulty,we develop a high-order field theory on heterogeneous manifolds for classical particle-field systems and apply it to derive exact,local conservation laws,in particular the energy-momentum conservation laws,for the electromagnetic gyrokinetic system.A weak Euler-Lagrange (EL) equation is established to replace the standard EL equation for the particles.It is discovered that an induced weak EL current enters the local conservation laws,and it is the new physics captured by the high-order field theory on heterogeneous manifolds.A recently developed gauge-symmetrization method for high-order electromagnetic field theories using the electromagnetic displacement-potential tensor is applied to render the derived energy-momentum conservation laws electromagnetic gauge-invariant.     

Transmissivity of electromagnetic wave propagating in magnetized plasma sheath using variational method

A variational method is introduced to analyze the transmissivity of an electromagnetic wave propagating in the magnetized plasma sheath. The plasma density is modeled by two parabolic inhomogeneous regions separated by one homogeneous region. The Lagrangian density of the system is constructed based on the fluid energy density and the electromagnetic energy density.The total variation of the Lagrangian density is derived. The fluid and electromagnetic fields are numerically solved by expansion in piecewise polynomial function space. We investigate the effect of an external magnetic field on the transmissivity of the electromagnetic wave. It is found that the transmissivity is increased when an external magnetic field is applied. The dependence of transmissivity on the collision frequency between the electrons and the neutral particles has also been studied. We also show that the external magnetic field causes a shift in the critical frequency of the plasma sheath.     

环境电磁场自动测试系统

本文讨论了对环境电磁波区域性背景场强测量使用自动测试系统,该系统由自动频谱分析仪,宽带各向同性天线,计算机等组成,其优点是可靠、快速、方便,为国内开展环境电磁波场强测量提供一部分新的设备。