铁基超导线带材研究现状及展望

铁基超导体具有极高的上临界磁场、较小的各向异性、简单的制备工艺等优点,在高场超导磁体、核磁共振谱仪、可控核聚变装置、高能粒子加速器等领域具有重要的应用前景。为满足上述高场强电应用需求,必须制备出高性能超导线带材。文章详细介绍了多种体系铁基超导线带材的研究进展,分析当前线带材研究中存在的问题,提出改善线材传输性能的途径,并对铁基超导线材的发展趋势进行展望。     

基于单片机的LED旋转式显示屏设计

基于视觉暂留特性设计并制作了一个13点线阵LED模块的显示屏。该系统可实现中文字符的显示和动态特效显示,将STC89C52单片机与发光二极管模块固定在电机的旋转轴上通过电机的旋转带动模块转动,再利用单片机控制发光二极管的亮灭,最后利用人眼的视觉暂留,构造出一个旋转的LED显示屏。     

Identification of a 9/2-[505] isomer in the neutron-rich 193Os nucleus

The neutron rich nucleus ¹⁹³Os was produced in the ¹⁹²Os(⁷Li, ⁶Li)¹⁹³Os reaction. An isomeric state based on the 9/2^-[505] Nilsson orbital was identified in the present work. The half-life of the isomeric state was extracted and discussed in terms of the K quantum number. A level scheme built on the isomeric state was proposed based on the experimental data.     

海洋波导中刚性球及旋转椭球前向散射场时频特征的畸变

利用波导中目标声散射理论的简正波方法,数值模拟了自由空间和浅海均匀波导中刚性球、旋转椭球的散射场,分析了波导中刚性体前向散射时频特征的畸变规律。仿真结果表明:波导中刚性体的前向散射时域波形与频谱特征受波导制约;目标散射场的固有特征受波导色散特征的调制,时频谱上呈现出由于色散的简正波间的耦合而导致各简正波能量条纹界限模糊的现象。时频特征的畸变程度与组成散射共振系统的波导、目标的尺度以及散射体布放深度有关,随波导底质透声能力和深度增加、散射体散射强度(信混比)增强而减弱。     

混沌时序相空间重构的分析和应用研究

在国内外学者工作的基出上,应用Legendere坐标法重构动力系统的相空间,研究了时序时隔τ的取值范围,讨论了时序间隔τ对相空间重构工作的影响,并用所提方法重构了系统的吸引子.算例表明所提方法是有效的.     

Pressure Effects on Spectra of Tunable Laser Crystal GSGG:Cr3+ I: Theory

A theory for shifts of energy spectra due to electron-phonon interaction (EPI) has been developed. Both thetemperature-independent contributions and the temperature-dependent ones of acoustic branches and optical brancheshave been derived. It is found that the temperature-independent contributions are very important, especially at lowtemperature. The total pressure-induced shift (PS) of a level (or spectral line or band) is the algebraic sum of its PSwithout EPI and its PS due to EPI. By means of both the theory for shifts of energy spectra due to EPI and the theoryfor PS of energy spectra, the total PS of R1 line of tunable laser crystal GSGG:Cr3+ at 70 K as well as the ones of itsR1 line, R2 line and U band at 300 K will be successfully calculated and explained in this series of papers.     

全光纤量子保密通信中的偏振控制

介绍了在全光纤量子保密通信系统的量子信道中利用可转动光纤圈型偏振控制器实现对光纤偏振态的测量和调整.实验证明该方法能有效控制光纤中的偏振态.     

不同截面尺寸Bi-2223多芯带材的错配角

采用输运电流方法测试了37芯Bi2223带材的平均错配角.带材的错配角随带材厚度的降低而减小,同时带材Jc升高.但过薄的带材由于加工不稳定易导致Ag/超界面不规则现象,并破坏界面晶粒取向,造成错配角增大.     

Elevation of the Power Factor of Co4Sb12 Skutterudite with Sm-Doping in High-Pressure High-Temperature Synthesis

A thermoelectric material Smx Co4Sb12 （0（ x ≤1.0） is synthesized at high pressure and high temperature leading to an enhanced power factor. The experimental measurements show that the SmxCo4Sb12 compounds exhibits n-type conduction. The absolute value of the Seebeck coefficient decreases with increasing Sm fraction. The resistivity increases with samarium content x from 0.1 to 0.2, but decreases dramatically when x changes from 0.2 to 1.0. The maximum power factor reaches 13.1 μW.cm^-1K-2 at x =1.0, which is larger than the data previously reported for the La-doped CoSb3 prepared at room pressure.     

An analysis of seismic attenuation in random porous media

The attenuation of seismic wave in rocks has been one of the interesting research topics, but till now no poroelasticity models can thoroughly explain the strong attenuation of wave in rocks. In this paper, a random porous medium model is designed to study the law of wave propagation in complex rocks based on the theory of Biot poroelasticity and the general theory of stochastic process. This model sets the density of grain, porosity, permeability and modulus of frame as random parameters in space, and only one fluid infiltrates in rocks for the sake of better simulation effect in line with real rocks in earth strata. Numerical simulations are implemented. Two different inverse quality factors of fast P-wave are obtained by different methods to assess attenuation through records of virtual detectors in wave field (One is amplitude decay method in time domain and the other is spectral ratio method in frequency domain). Comparing the attenuation results of random porous medium with those of homogeneous porous medium, we conclude that the attenuation of seismic wave of homogeneous porous medium is far weaker than that of random porous medium. In random porous media, the higher heterogeneous level is, the stronger the attenuation becomes, and when heterogeneity σ = 0.15 in simulation, the attenuation result is consistent with that by actual observation. Since the central frequency (50 Hz) of source in numerical simulation is in earthquake band, the numerical results prove that heterogeneous porous structure is one of the important factors causing strong attenuation in real stratum at intermediate and low frequency.