Si／C复合材料电极首次嵌锂过程的电化学阻抗谱研究

采用球磨法制备了Si／C复合材料,X射线衍射（XRD）和扫描电子显微镜（SEM）测试结果显示Si／C复合材料中硅保持着良好的晶体结构且均匀的分散于炭黑基体中．充放电测试结果表明Si／C复合材料首次放电容量高达3393mAh／g,4周之后可逆容量均保持在1000mAh／g左右,表现出较好的循环性能．电化学阻抗谱测试结果显...     

First experimental research in low energy proton radiography

Proton radiography is a new scatheless diagnostic tool providing a potential development direction for advanced hydrotesting.Recently a low energy proton radiography system has been developed at the Chinese Academy of Engineering Phyiscs(CAEP).This system has been designed to use an 11 MeV proton beam to radiograph thin static objects.This system consists of a proton cyclotron coupled to an imaging beamline,which is the first domestic beamline dedicated to proton radiography experiments.Via some demonstration experiments,the radiography system is confirmed to provide clear pictures with spatial resolution～100μm within 40 mm field-of-view.     

Imaging beamline for high energy proton radiography

Proton radiography is a new tool for advanced hydrotesting. This article will discuss the basic concept of proton radiography first, especially the magnetic lens system. Then a scenario of 50 GeV imaging beamline will be described in every particular, including the matching section, Zumbro lens system and imaging system. The simulation result shows that the scenario of imaging beamline performs well, and the influence of secondary particles can be neglected.     

Theoretical and experimental study of transient response of the Yb-doped fiber amplifier

Some analysis of the transient response of the Yb-doped fiber amplifier are performed by solving a set of time-dependent rate and power transfer equations based on finite-difference method.Meanwhile,the variation of time to reach the steady state for upper level population distribution,the forward and backward amplified spontaneous emissions(ASEs)and stored energy on the system parameters including pump power,fiber length,Yb-doped concentration,and core area are numerically simulated,respectively.The results show that,by optimizing pump pulse width,stored energy can reach or even exceed the steady state value of continuous wave(CW)pump.By increasing Yb-doped concentration and core area,stored energy is increased,the ASE is suppressed and the ASE built-up time is postponed.In addition,the experimental results show the validity of the theoretical ASE built-up time.The obtained results can provide important guiding for the optimization of pump pulse width and fiber parameters.     

基于DMD的数字全息显示及其再现像质增强

采用DMD作为空间光调制器构建了一套数字全息显示系统.分析了数字全息图光学再现中影响再现图像质量的因素,提出了一种采用频域滤波重建高条纹对比度滤波全息图来改善其光学再现图像质量的新方法.采用信噪比及图像亮度作为评价参量,对原始全息图和滤波全息图的数值再现像进行定量分析表明,滤波后全息图的再现像质量明显优于原始全息图的再现像.基于DMD数字全息显示系统的光学再现实验也验证了理论分析结果.     

激光加工微孔工艺及质量研究

随着高端精密装备的飞速发展，人们对高质量微孔的需求越来越迫切。激光加工凭借其加工精度高、效率高、无污染、应用材料范围广等优点成为微孔加工制造的首选方法。文章首先对激光加工微孔的质量特征(如深径比、锥度、圆度等)进行了介绍；其次总结归纳了激光加工方式(复制法和轮廓迂回法)、辅助方式(真空、气体、水等因素)和超声-激光复合加工对微孔质量的影响；最后对激光加工微孔存在的问题进行总结，并对未来发展方向进行了展望。     

安全播出监测监管系统在广播电视工程领域的应用

安全播出关系到广播电视行业的健康发展，国家广播电视总局及各省市县广播电视单位高度重视安全播出管理工作。安全播出监测监管系统是基于大数据、人工智能、云计算等信息技术的智慧监管平台，有助于推进广播电视“智慧运维”“智慧监管”。基于此，以安全播出监测监管系统在广播电视工程领域的应用为研究重点，分析广播电视安全播出发展历程，探讨安全播出监测监管系统在广播电视工程领域的应用，为广播电视单位安全播出监测监管系统建设提供可供参考的建议，提升安全播出保障体系保障能力。