相对论平均场理论对A=48同质量数链原子核对称能的研究

最新研究发现原子核对称能与平均的能级密度和同位旋矢量势直接相关. 在相对论平均场理论中, 势场可以分为同位旋矢量和同位旋标量两部分. 采用PK1，NL3, NLSH和TM1相互作用参数, 对于A=48同质量数链, 分别了计算势场中包含或不含同位旋矢量项时的原子核结合能, 研究了原子核的对称能, 即平均能级间距ε和同位旋矢量势的有效强度κ.     

Beam halo experiment at IHEP

Space-charge forces acting in mismatched beams have been identified as a major cause of beam halo. In this paper,we describe the beam halo experimental results in a FODO beam line at IHEP. With this beam transport line, experiments are carried out to compare the measured data with the multi-particle simulations and to study the formation of a beam halo. The maximum measured amplitudes of the matched and mismatched beam profiles agree well with simulations. Details of the experiment are presented.     

全息光伏打聚光器的设计

本文描述了一种采用全息反射元件的分段谱光伏打聚光器,系统的转换效率可高于26%。分析了聚光器的特性并给出了全息元件的设计参数和制作方法。     

制导和监视用激光雷达进展

叙述激光探测雷达和激光成像雷达的发展现状，简要介绍它们在武器自主制导和监视方面的应用。     

苯并15冠5钯配合物：［K(B15C5)2］2［Pd(SCN)4］的合成与结构研究

合成了苯并15冠5与钯生成 的配合物：[K(B15C5)2]2[Pd(SCN)4],并通过元素分析,红外光谱及X射线单晶结构分析进行了表征,配合物为单斜晶系,空间群p21/n,晶体学数据：a=1.20430(7),b=1.93299(10),c=1.56680(9)nm,β=108.1190*10),V=3.4665(3)nm3,Z=2,F(000)=1424,R1=0.05000,wR2=0.1549.配合物由两个[K(B15C5)]2^ 配阳离子和一个[Pd(SCN)4]^2-配阴离子组成,四个硫氰酸根的硫原子与钯原子配位,[Pd(SCN)2]^2-为平面方形构型,K＋与2个冠醚环的10个氧原子成键而形成夹心型结构,两个苯并15冠5的苯环相对钾原子呈反式排列。     

纳米结构ZnxFe3-xO4-α-Fe2O3多晶材料中的巨隧道磁电阻效应

在具有纳米绝缘层的多晶锌铁氧体体系中,当晶界为α-Fe₂O₃纳米量级(6—7nm)的绝缘层时,则构成(Zn_xFe_3-xO₄)-α-Fe₂O₃非均匀体,高分辨电子显微镜已证实了这种微结构,该体系在0.5T磁场、4.2K温度下,磁电阻效应可达1280%,300℃下为158%. 关键词： 隧道磁电阻效应 锌铁氧体 纳米结构     

隧穿磁电阻效应磁场传感器中低频噪声的测量与研究

基于隧穿磁电阻效应(TMR)的磁场传感器具有很高的磁场灵敏度, 但同时噪声也较大,有效抑制TMR磁场传感器的噪声, 尤其是低频噪声的抑制对于其在高灵敏度要求场合的应用具有重要的意义. 本文采用高精度数据采集卡搭建了噪声测量系统, 测量了全桥结构TMR磁场传感器的噪声频谱图, 发现TMR传感器的噪声在低频段表现为1/f特性, 同时噪声功率谱密度与工作电流平方成正比关系; 低频噪声在自由层翻转区间内噪声急剧增大, 证明了1/f噪声主要来源于磁噪声, 这一结果为TMR磁场传感器的噪声特性优化指明了方向.     

Opacity of Hot and Dense Stellar Material： Flexible for Changes in Composition and Abundance

Opacity of stellar materials with the composition and relative abundance specified according to sun has been calculated by using an average-atom scheme, which is designed to treat electronic structures of atoms and ions in a mixture. Different relative abundances of the metallic elements are considered. Oomparisons between the present results and those of OPAL are made for the opacity to show that the difference is less than 10% for mostcases and less than 30% for the largest point with the density of 1.0g/cm^3 and temperatures from 50 to 6000eV. In view of the simplicity of the present approach, it is quite flexible to apply the method to different models of the stellar materials with changes in composition as well as in relative abundance.     

Design and construction of the first prototype ionization chamber for CSNS and PA beam loss monitor （BLM） system

Design and construction of the first prototype ionization chamber for CSNS and Proton Accelerator （PA） beam loss monitor （BLM） system is reported. The low leakage current （〈0.1 pA）, good plateau （≈800 V） and linearity range up to 200 Roentgen/h are obtained in the first prototype. All of these give us good experience for further improving the ionization chamber construction.     

DTA模型计算高温Fe等离子体的辐射不透明度

使用DTA(detailed term accounting)模型计算了温度为20eV、密度为0.01g×cm^-3的Fe等离子体的辐射不透明度.对于处于局域热动平衡(local thermodynamic equilibrium,LTE)下的Fe等离子体,使用Saha方程计算出各价离子的丰度.使用MCHF方法得到了Fe离子的能级以及束缚-束缚跃迁的振子强度,考虑了Doppler展宽和碰撞展宽的谱线展宽机制,谱线线型采用Voigt线型.束缚-自由以及自由-自由吸收截面分别使用DCA及AA模型得到.所得的结果与美国Los Anamos National Laboratory(LANL)使用LEDCOP程序计算的结果进行了对比,两种结果符合很好.