海洋激光雷达测量海中悬移质

研制了一套采用倍频YAG激光器的小型海洋激光雷达，用于测量海中悬移质浓度，2000年8月28日至9月5日，该系统安装于“东方红Ⅱ”号右舷下甲板，在渤海海区进行海中悬移质浓度现场测量，通过对18个站位的海洋激光雷达数据分析，获得的表层悬移质浓度与同步测量的海中悬移质浓度结果吻合较好。     

利用模式的对称性研究光子晶体光纤的色散

由光子晶体光纤的对称性可以得到模式分布的对称性，根据模式的对称性选择适当的展开函数，可以使计算量大大减少。计算了六角结构光子晶体光纤的色散特性，得到了波长在1．55pm处色散为零时，光子晶体光纤的结构参量所满足的方程。     

Study on Dual Bragg Wavelength Fiber Grating and Its Tuning Scheme

Because of package, a single FBG has dual Bragg wavelength. One is sensitive to stress and the other is sensitive to temperature. By using the special mechanism, the wavelengths can be tuned by stress and temperature respectively.     

互补型自适应滤波器在心磁信号处理中的应用

将心磁信号从干扰噪声中加以提取并有效地消除噪声干扰是心磁信号处理中尤为重要的环节 .从改进算法的角度出发，提出互补型自适应滤波器结构以实现心磁信号的消噪处理.该滤波器针对心磁这类非平稳信号进行设计，有效地解决了常规自适应滤波器应用于心磁信号处理时收敛速度和稳态误差的矛盾.通过仿真实验和心磁实验结果表明，该算法能有效地消除心磁信号的背景噪声和工频干扰噪声.同时该算法也可用于其他非平稳信号的消噪处理. 关键词： 自适应滤波 心磁图 最小均方误差     

The effect of Mn substitution on thermoelectric properties of Ca3MnxCo4−xO9 at low temperatures

The effects of partial substitution of Mn for Co on the thermoelectric properties of Ca₃Mn_xCo_4−xO₉ (x=0, 0.03, 0.9), prepared by sol-gel process, were investigated at the temperatures from 380 K down to 5 K. The results indicate that the substitution of Mn for Co results in increase in thermopower at temperatures >∼80 K, and substantial (23-31% at 300 K) decrease in lattice thermal conductivity in the whole temperature range investigated. The temperature behavior of ZT suggests that Ca₃Mn_xCo_4−xO₉ with light Mn substitution would be a promising candidate for high-temperature thermoelectric applications.     

厚高阶光学非线性介质Z扫描的变分法分析

利用变分法对具有五阶光学非线性介质的Z扫描特性进行了研究。通过比较，发现当介质在具有较大的五阶非线性系数或较大光强的情况下，五阶非线性项的作用是不可忽略的。这对光限制器的设计和Z扫描实验都具有一定的指导意义。     

The Synthesis of Glycoglycerolipids

A convenient synthetic route was developed for the synthesis of the novel glycolipids: 1,2-di-O-acyl-3-O-(2‘-acylamide-2‘-denxy-ct-D-glucopyranosyl)-sn-glycerols. 10 new compounds of glycolipids with different acyl groups were obtained.     

On the even power mean of a sum analogous to Dedekind sums

Summary Our purpose is to extend results due to P. Chandra and L. Leindler concerning the order of approximation by means of Fourier series for functions belonging to generalized Lipschitz-classes.     

The solvability conditions for inverse eigenproblem of symmetric and anti‐persymmetric matrices and its approximation

The problem of generating a matrix A with specified eigen‐pair, where A is a symmetric and anti‐persymmetric matrix, is presented. An existence theorem is given and proved. A general expression of such a matrix is provided. We denote the set of such matrices by ??????_Eⁿ. The optimal approximation problem associated with ??????_Eⁿ is discussed, that is: to find the nearest matrix to a given matrix A* by A∈??????_Eⁿ. The existence and uniqueness of the optimal approximation problem is proved and the expression is provided for this nearest matrix. Copyright © 2002 John Wiley & Sons, Ltd.     

Near-Optimal Controls of Discrete-Time Dynamic Systems Driven by Singularly-Perturbed Markov Chains

This work is devoted to near-optimal controls of large-scale discrete-time nonlinear dynamic systems driven by Markov chains; the underlying problem is to minimize an expected cost function. Our main goal is to reduce the complexity of the underlying systems. To achieve this goal, discrete-time control models under singularly-perturbed Markov chains are introduced. Using a relaxed control representation, our effort is devoted to finding near-optimal controls. Lumping the states in each irreducible class into a single state gives rise to a limit system. Applying near-optimal controls of the limit system to the original system, near-optimal controls of the original system are derived.