Determinant Solutions Generalized KP Equation to a （3＋1）-Dimensional with Variable Coefficients

A system of linear conditions is presented for Wronskian and Grammian solutions to a (3+1)-dimensional generalized vcKP equation.The formulations of these solutions require a constraint on variable coefficients.     

由两个右特征对构造三对角四元数矩阵

讨论由两个右特征对构造三对角四元数矩阵的数值求解问题,给出了该问题有解的充要条件,以及解的具体表达式.在已知两个特征对的条件下,进一步给出了三对角自共轭、三对角正定四元数矩阵的存在条件及计算方法.     

低温预冷换热规律及表面改性影响研究

调研了低温管路预冷及两相换热的研究现状,阐述了低温预冷瞬态换热特性;介绍了金属表面改性对预冷规律的影响,仿真了低导热涂层管的预冷换热规律.研究发现:液氮预冷主要由膜态沸腾支配,且预冷耗时较长;液氢预冷未见膜态沸腾,预冷耗时更短.促进膜态沸腾向过渡沸腾的更早转化有利于预冷加速,且转化温度迁移可通过内壁表面结构改性实现,可...     

基于自制超稳定F-P腔压窄632.8nm外腔半导体激光线宽的实验研究

窄线宽激光由于其具有单色性好、稳定度高、相干长度长等优点,广泛应用于光电检测领域,包括相干通信、精密测量、光学频率标准、吸收光谱计量以及光与物质相互作用研究等.目前频率稳定的氦氖激光器线宽可以达到M Hz量级,分布反馈式(DFB)光纤激光器线宽可达kHz量级,DFB半导体激光器线宽可以达到M Hz量级,然而光栅反馈半导...     

The Fourier Pseudospectral Method for Two-Dimensional Vorticity Equations

In this paper we develop a Fourier pseudospectral method forsolving two-dimensional vorticity equations. We prove the generalizedstability of the schemes and give convergence estimations dependingon the smoothness of the solution of the vorticity equations. Spectral methods have been applied widely to the partial differentialequations of fluid dynamics [4–11]. Guo Ben-yu proposeda technique to estimate strictly the error of the spectral schemesfor the K.D.V.-Burgers equation, the two-dimensional vorticityequations, and the Navier-Stokes equations [5,6,8]. On the otherhand, the authors [7,10] developed a pseudospectral method byusing Riesz spherical means to get better results. In this paper,we generalize this method to two-dimensional vorticity equations.The generalized stability and the convergence are proved. Thenumerical results show the advantage of such a method.     

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.     

n维单形的Erd“非汉字符号”-Mordell型不等式

本文利用距离几何的理论和方法证明了 En( n≥ 2 )中 n维单形几内任一点到 n- 1维界面的距离与它到顶点的距离的一个带权的 Erdos- Mordell型不等式 ,并由此导出了涉及 n维单形的内任一点的一组儿何不等式 ,其中包括三角形中著名的 Child不等式的高维推广     

激光诱导击穿光谱结合标准加入法定量分析未知样品中铅含量

利用激光诱导击穿光谱结合标准加入法定量分析了铅蓄电池厂含铅污泥中重金属铅元素含量,标准加入法有效避免了外标法与内标法制作标准曲线时基质不同对LIBS检测结果的影响,且样品处理过程简单。实验采用中心波长为1 064 nm的Nd∶YAG脉冲激光器作为激发光源,以高分辨率、宽光谱段的中阶梯光栅光谱仪和增强型电荷耦合器件为谱线分离与探测器件,选取铅的PbⅠ：405.78 nm特征谱线作为分析线,以FeⅠ：404.58 nm特征谱线作为内标线进行结果计算。预实验确定较佳的实验条件后(激光脉冲能量：128.5 mJ,延时：2.5 μs,门宽：3 μs),对铅蓄电池厂的未知铅泥样品中铅元素进行定量分析,结果表明加入铅在0~25 000 mg·kg-1范围内谱线不会产生自吸收,PbⅠ：405.78 nm信号强度与铅加入量呈很好的线性关系,由此确定合适的铅加入量为0~25 000 mg·kg-1。在此基础上配制四个样品,基质均为铅蓄电池厂含铅污泥,加入铅浓度分别为5 000,10 000,15 000,20 000 mg·kg-1,每个样品设置三个平行样,验证实验重复性及可靠性,并与ICP-MS检测结果对比,结果直线外推误差为-14.8%。12个样品单次计算结果误差介于为-24.6%~17.6%之间,含铅量平均值为43 069 mg·kg-1,相对误差为-2.44%。     

非齐次线性差分方程的Cm解[英文]

设c0,c1,…,cn均为实的常数，F（x)是个从R到R的C^m映射。本文讨论了非齐次线性差分方程∑i=1ncif(x i)=F(x)的C^m(m≥0）的存在性和唯一性。     

用于空间激光通信的InGaAsP 激光二极管辐射损伤研究(英文)

对1:55 μm波长DFB 结构的InGaAsP 多量子阱激光二极管开展电子和60Co- 射线辐照试验。试验结果表明,激光二极管的斜度效率主要受带电粒子沉积的电离总剂量影响,而阈值电流和光功率主要受位移损伤剂量的影响。利用位移损伤剂量方法评价激光二极管的辐射损伤特征,并且预测其在空间辐射环境中的光功率衰退情况。模拟计算结果表明,MEO轨道辐射环境对激光二极管光功率辐射损伤远大于GEO轨道的影响,这主要是由于MEO轨道辐射环境的高能电子通量密度远大于GEO轨道的通量密度。The 1.55 μm InGaAsP multi-quantum-well laser diodes with distributed feedback structures were irradiated by electrons and 60Co- rays. The experimental results show the slope efficiency of laser diode is mostly affected by the total ionizing dose produced by charging particles, and the threshold current and the optical power mainly by displacement damage dose. The displacement damage dose methodology was employed to evaluate radiation damage of the laser diodes, and to predict the power degradations of these diodes in space. The calculated results indicate that the optical powers of the diodes will have more serious degradation for medium Earth orbit than for geosynchronous Earth orbit,due to higher fluence density of high energy electrons in GEO orbits.