On optimal message vector length for block single parallel partition algorithm in a three-dimensional ADI solver

It has long been recognized that many direct parallel tridiagonal solvers are only efficient for solving a single tridiagonal equation of large sizes, and they become inefficient when naively used in a three-dimensional ADI solver. In order to improve the parallel efficiency of an ADI solver using a direct parallel solver, we implement the single parallel partition (SPP) algorithm in conjunction with message vectorization, which aggregates several communication messages into one to reduce the communication costs. The measured performances show that the longest allowable message vector length (MVL) is not necessarily the best choice. To understand this observation and optimize the performance, we propose an improved model that takes the cache effect into consideration. The optimal MVL for achieving the best performance is shown to depend on number of processors and grid sizes. Similar dependence of the optimal MVL is also found for the popular block pipelined method.     

Characterization of 3-bridge links with infinitely many 3-bridge spheres

In an earlier paper, the author constructed an infinite family of 3-bridge links each of which admits infinitely many 3-bridge spheres up to isotopy. In this paper, we prove that if a prime, unsplittable link L in S³ admits infinitely many 3-bridge spheres up to isotopy then L belongs to the family.     

Aeroelastic Wind Forces on Flexible Bridge Girders

Non-stationary aeroelastic wind force processes on a streamlined bridge deck are modelled for use within computations in the range of statistically stationary girder oscillation and for the mathematical investigation of the limit of aeroelastic stability. Time Domain (TD) methods, as the direct integration on a finite-element (FE) model, are applied in structural analyses for taking into consideration both geometric and physical nonlinearities. The FE method requires a continuous form of the force model, which permits an arbitrary discretization in time. The present model is based on continuous step response functions of Wagner-type, taking advantage of modern advances of that theory. Special emphasis is put on the continuity and the existence of equivalent representations in time and frequency domains. A realistic wind load model must include measured force functions and effects from the wind turbulence. For that reason, the force functions are calibrated in wind tunnel tests on section models in grid turbulence and boundary layer flow. The aeroelastic in-phase and out-of-phase forces are identified from highly accurate calibrations experiments on section models up to high frequencies which permits to decrease the time step increment. Turbulence effects on the aeroelastic coefficients are included in mean terms.     

ICP-AES测定Ni-Cr合金在人工唾液中析出的Ni离子

在模拟口腔环境下用人工唾液浸泡Ni-Cr桥,150h后采用ICP-AES测定Ni-Cr桥在人工唾液中的Ni离子析出量.镍在0.01-7.5μg/mL内有良好的线性关系,相关系数为0.9998;方法检出限为0.0059μg/mL;标准加入法测定镍的回收率为92.3%-99.8%.     

多种通信手段在遇险救生体系中的应用研究

我国海域辽阔,各类船只的水上航行和作业安全密切关系到生命和财产的安全,需要可靠保障。由于海上险情发生的随机性和突发性,岸上险情监视力量必须全时、全天候地开设险情通信通道,接收海上遇险对象的遇险呼救信号并及时对遇险信息进行处理。因此,岸基必须建设遇险救生信息系统并规定必要的信息传输流程,保障险情报知通信的顺利完成。文章简要分析了目前海上救生的通信现状,对常用通信手段进行了分析与介绍,并提出了一种整合各通信手段的设计方法,实现了多种通信手段的综合使用以及统一调度,大幅提升险情信息的传输和处理效率,提高险情信息的保密性,为救援工作提供了精确可靠的问责手段。     

Average mutual information of the random block-message ensembles for many-letters

By making use of the theoretical framework presented by Bostroem(K.J.Bostroem,LANL quant-ph/0009052),we generalize the standard quantum information theory of block messages with fixed block length to the variable one.We show that the states belonging to a sufficiently large hilbert space are the highly distinguishable states.We also consider the collection states (product states of more than one qubit state) and seek a “pretty good measurement” (PGM) with measurement vectors to improve the mutual information.The average mutual information over random block-message ensembles with variable block length n is discussed in detail.     

红外光谱对碱土金属二元羧酸盐结构的研究

研究了三十种二元羧酸金属盐的红外光谱，讨论了金属离子和二元酸的种类对二元酸盐配位结构的影响。发现Mg盐、Ba盐，Sr盐为螯合配位，Ca盐，Zn盐中同时存在螯合配位和桥式配位，二元酸的种类对羧酸盐配位结构没有影响。对羧酸盐在常温和熔融后的栩位方式和结构上的差异的研究结果表明，Mg盐，Ca盐与Sr盐，Ba盐在熔融后的结构变化不同。     

Stable anticipation synchronization in mutually coupled vertical-cavity surface-emitting lasers system

Two vertical-cavity surface-emitting lasers(VCSELs) are mutually coupled through a partially transparent mirror (PTM) placed in the pathway. The PTM plays the role of external mirror,which controls the feedback strength and coupling strength.We numerically simulate this system by establishing a visible SIMULINK model.The results demonstrate that the anticipation synchronization is achieved and it can tolerate some extent frequency detuning.Moreover,the system shows similar chaos-pass filtering effect on unidirectionally coupled system even both VCSELs are modulated.This system allows simultaneously bidirectional secure message transmission on public channels.     

SUN5500小型机MPI编程与蕴式并行计算的实现方法

基于SUN5500小型计算机并行开发环境，给出了消息传递模型和蕴式行模型的实现方法，通过实例分析了SUNMPI实际编程，并对选取不同模型有不同参数的运算时间进行了比较，结果表明，在SUN5500计算机上MPI模型和蕴式并行模型均能较大地提高运算速度，而且MPI在灵活性和并行程度方面更优。     

超导故障限流器的研究现状及其应用

超导故障限流器(Superconducting Fault Current Limiter,SFCL)是利用超导体的基本特性,有效限制电力系统故障短路电流,提高电网安全性和稳定性的一种新型电力设备。文中在综合大量文献的基础上,对超导故障限流器进行了一种较为系统的分类。基于该种分类,结合目前国内外的研究现状,就电阻型、磁屏蔽型、饱和铁芯电抗器型、桥路型SFCL的工作原理作了详细的分析介绍,还给出了它们在电力系统中的安装位置。最后,对超导故障限流器的研究中存在的问题及其发展趋势做了说明。