针对宽带测量系统特点,将测量系统建模为滤波器,形成了标定过程的数学模型.在此基础上推导了滤波器模型-3dB通带频率上限与其标准方波响应前沿、-3 dB通带频率下限与其标准方波响应平顶降的关系式.这2个关系式可用于对实际宽带测量系统-3 dB通带上下限的工程估计.针对实用需求,分析了输入和滤波器模块参数对估计结果的影响,进而给出了工程估计准则.

电磁脉冲效应实验是对被试系统的模拟实验,在模拟器下开展,实验中需要测量被试系统内部的耦合场、感应电流和电压等效应参数.随着测量规模的增大,需要研制一种新的电磁脉冲同步触发系统,用于解决电磁脉冲效应实验参数测量中多台示波器的同步触发问题.该种电磁脉冲同步触发系统包括一种电磁脉冲效应实验触发信号测量系统和一种触发方法.效应实验触发信号测量系统放置于模拟装置下,用于测量触发信号.一种触发方法通过触发信号和同步触发装置去同步触发多台示波器.通过多次实验验证,该同步触发系统具有高可靠性和高稳定性,可以完成多台示波器的同步触发,在工程应用中实用性强,保证了实验的顺利完成.

提出了合金吸气剂除杂-气相色谱法测定混合气体中氪、氙含量的方法.样品通过减压进样装置进入气相色谱仪,选用管径为3.18 mm、长度为100 cm的不锈钢管为除杂柱,填装合金吸气剂,以消除氮气、氢气等杂质气体对氪、氙测定的干扰.结果显示:氪、氙的体积分数分别在4.55×10-4％～2.65×10-3％,5.60×10-5％～3.29×10-4％内与其对应的峰面积呈线性关系,检出限(3S/N)分别1.71×10-6％,1.65×10-6％;对混合标准气体重复测定6次,峰面积的相对标准偏差均不大于1.0％;按照试验方法与文献报道的气相色谱-质谱法对6个混合气体样品进行测定,相对偏差的绝对值均不大于1.0％.

针对高空核电磁脉冲(HEMP)模拟器建设和效应研究中脉冲磁场测量的需求,介绍了一种快前沿脉冲磁场测量系统的设计、标定和使用过程.首先,依据等效电路分析了电小环天线的测量原理和频率特性;其次,建立了小环天线数值计算模型,研究了其脉冲接收特性;然后,通过电路模拟的方式研究了电路参数对测量结果的影响;最后,设计了一种快前沿B-dot传感器,结合积分器和光纤传输系统构建了一套快前沿脉冲磁场测量系统,测试了其性能指标,并在高空核电磁脉冲模拟器下取得了应用和验证.结果 表明:该测量系统上升时间小于1 ns,满足快前沿脉冲磁场测量需求.

基于带状线微波导行原理,设计了一种宽频带开放式横电磁波传输室,推导了特性阻抗与几何尺寸间的关系式,确定了特性阻抗为50 Ω时的传输室几何尺寸,并通过建模分析,研究了传输室的频率特性.实验测试结果表明,设计的传输室特性阻抗为 52.2 Ω,在频率小于628 MHz的范围内,电压驻波比小于2.2.该传输室可用于电磁脉冲传感器标定和小型电子设备的 HEMP效应研究.

In order to better predict the wire crosstalk problem, an Elman feedback neural network method was proposed.The feedback neural network method had a strong associative memory and optimization calculation function, used the parameters related to the wire crosstalk response as the input of the network, and took the predicted coupling voltage value of the wire as an output.The training data used by the Elman feedback neural network was calculated for the multi-conductor transmission line method.Finally,the feedback neural network prediction model obtained by training was used to predict unknown samples,and the prediction results and real test results were compared.The Experimental results show that the established Elman neural network had less prediction error for wire crosstalk problems and the result was more accurate.

The induced current for 200 m length insite cable of transportable systems illuminated by early-HEMP is calculated using transmission line method,and the waveforms of the induced current is analyzed.The rationality that the early-HEMP protection requirements for insite cable of transportable systems prescribed in MIL-STD-188-125-2 can be used in the EMP environment described in GJB 1389A-2005 is validated.

讨论了集成光学电场探头测量高空电磁脉冲(HEMP)的系统误差.根据探测器传输函数和HEMP的表达式得出了误差方程.并通过对HEMP表达式的特征分析,对误差方程进行了简化.通过方程的求解,分析了探测器和HEMP波形的各项参数对测量结果的影响.结果表明:误差随着双指数波幅值、半宽/前沿和探测器工作点漂移的增大而增大;探测器的5％和10％系统测量误差对应的最大测量幅值分别为半波电场的0.165倍和0.23倍.该结论可为此类探测器的使用提供参考.

Radioactive isotopes of xenon are produced in nuclear facilities,and must be trapped before released into the atmosphere.Study on the adsorption behavior of Xe isotopes in air or other gaseous medium is of great importance.For the perspective of engineering application,direct adsorption of multi-component gas at room temperature using activated carbon was studied.The comparison between multi-stage and single-stage carbon column adsorption was carried out, and the effects of condition parameters including carbon consumption were investigated.Experimental results show that single-stage carbon column is easier to be achieved in engineering application as compared with the way of multi-stage adsorbing column.For single-stage carbon column,the adsorbing efficiency of Xe reaches 90% with a gas flow velocity of 0.33 cm/s,and the resistance from the carbon bed is negli-gible in a certain flow velocity range (0.02-1.2 cm/s).

A measurement&control and Information Management System is built for the need of High-altitude Electromagnetic Pulse ( HEMP) Experiment.The distributed management&control system is based on network communication and communicates with other devices with the aid of VISA technology and graphic programming language LabVIEW.The system has the following functions, such as data acquisition, signal processing, data-base management, and report generation, etc.The System is effective and normative, with good transportability and scalability.The system has been used during the HEMP experiment and makes the test more efficient and standard.

目前电光调制器偏置点自动控制通常采用小信号扰动法,主要应用于高速数字通信,而不适用于模拟信号传输.为此提出了一种迭代算法,通过闭环控制实现调制器最佳偏置点的锁定.从理论上分析了方法的可行性,并搭建了反馈系统.在变温环境中进行了偏置控制实验,结果表明,环境温度变化率为5℃/min时,被测调制器功率抖动小于1.5％,该方法可用于模拟信号的传输.

以PbO,MgO,Nb2O5,TiO2为原料,采用两步固态反应法制备了纯钙钛矿相的0.92PMN-0.08PT陶瓷,并对其相的组成、微观形貌、介电性能和储能性能进行了研究.在25℃,1 kHz条件下,该陶瓷的相对介电常数高达27 480,介电损耗tanδ仅为4％,电滞回线形状细长,剩余极化很小,可释放的能量密度达0.31 J·cm-3.结果表明:室温下该陶瓷具有优良的介电和储能性能.

When using Marching-on-in-Time(MOT) method to solve time domain electric field integral equations,if the time axis of the model is divided by varying steps,the number of the cells needed for calculation will be reduced,but the interpolation will be impossible. To solve this problem,we use inorder traversal of the full binary tree to re-arrange the calcu-lation sequence of time and space,thus fulfill the interpolation.The currents of the linear antenna and the conical-plate electromagnetic pulse simulator are calculated using this Marc-hing-on-in-Time-varying step method.The results are in accordance with those obtained by the MOT method with uniform time steps and the simulation results by the well-known soft-ware CST,but time-consuming is only 41.16% of that by the MOT method with uniform time steps for the current calculation of the conical-plate electromagnetic pulse simulator.At last,the ratio of the number of unknowns in our method to that in the MOT method with u-niform time steps is given out to show our method will save computational cost.

The absorption and separation method of Xe and Kr gas by active carbon was investigated.A standard mixture of Xe and Kr flowed through the active carbon column to be absorbed and enriched at low temperature(-78 ℃).The absorbed Xe and Kr were then deabsorbed from the carbon column separately.The analysis of the experimental data shows that the recoveries of Xe and Kr are greater than 90%.It can be concluded that the decontamination coefficient for Xe from Kr environment is above 104,while the decontamination coefficient for Kr from Xe is no less than 103.

The retention time of Xe and Kr can be varied by changing the flow rate of carrier gas and temperature of the chromatography column packed with 5A molecular screen.It can be used for separating the noble gases.Test results show that an enhanced decontamination factor can be observed by extending the interval between retention times of Kr and Xe.Over 95% of the Kr and Xe can be absorbed by active carbon at –80oC.

In order to monitor radioactive krypton distribution in the environment,active charcoal is used to enrich krypton before the sample can be submitted to further laboratory analysis.The importance and method of krypton enrichment were presented.The absorption behavior of krypton by charcoal was analyzed.The experimental setup was designed to investigate effects of working temperature,linear velocities,partial-pressure of krypton on the enrichment of krypton by charcoal.The micro-structure parameters of the absorbing material to characterize its absorbing property was used,and the experimental data with theoretical analysis to conclude that for CF-1450 was fitted.The saturation absorption capacity at 191 K is 32.9 mL/g.