基于遗传算法的门限自回归模型在浅层地下水位预测中的应用

提出了建立门限自回归模型的一种简便通用的方法，用遗传算法可同时优化门限值和自回归系数．实例计算的结果说明了其可行性和有效性．该方法在各种工程时序预测中具有广泛的应用价值     

岩石爆破的逾渗模型

本文在分析几种典型的岩石爆破损伤模型的基础上，发现岩石爆破损伤演化具有明显的逾渗效应。采用逾渗来描述岩石爆破损伤断裂这一动态过程是可行的，并提出了进一步可能的研究途径。     

分子振动态及其跃迁的激光相干控制

讨论了激光合成相干叠加态的原理及其性质 ,针对 XY2 型分子 ,证明了合成局域模振动的可行性 ,然后给出相干叠加态的跃迁几率特征 ,发现它仍表现出相干的特性 ,对之进行分析研究表明 ,分子的振动态具有可控性 ,态跃迁几率具有可控性。     

复杂目标近场电磁散射的可视化计算方法

首次介绍了复杂目标近场散射计算的可视化方法。采用非均匀有理Ｂ样条曲面（ＮＵＲＢＳ）精确构造任意形状散射体，结合几何体近场透视变换和Ｚ－Ｂｕｆｆｅｒ技术实现了基于Ｗｉｎｄｏｗｓ平台的近场散射计算。提出广义雷达散射截面的概念并给出的若干算例。该方法充分利用了计算机３Ｄ图形设备的几何运算能力，运算速度快，严谨高，可扩展性好。     

Improved performances of a S-SEED using extremely shallowquantum-wells and asymmetric Fabry-Perot cavity structure

The authors report significantly improved performances of a symmetric self-electrooptic-effect device (S-SEED), with high on-off contrast ratio (>30:l) and large optical bistability loop widths (ΔP=44%) at an applied bias of V_a=0 V, i.e., with no power supply. The S-SEED is made of extremely shallow quantum wells (ESQWs) in an asymmetric Fabry-Perot (AFP) cavity structure. At V_a =5 V ΔP increased by up to 95%, preserving the high contrast ratio. The reflectivity changes at V_a=0 and 5 V were about 15% and 30%, respectively. These are believed to be the largest values ever reported for such structures     

Permeation of Zidovudine and Probenecid from Oily Bases Containing Alcohols Through Rat Skin

Permeation of zidovudine (3'-azido-3'-deoxythymidine, AZT) and probenecid from oily bases containing an alcohol through rat skin was examined. Isopropyl myristate (IPM), as an oily vehicle, showed a penetration enhancing effect for AZT and probenecid. Ethanol, n-propanol, and n-butanol were used as additives in IPM and were examined for their own permeation and the enhancing effect on the permeation of AZT and probenecid. The skin permeation of AZT and probenecid from IPM was enhanced by addition of the alcohol in IPM. The degree of the enhancement was decreased with increasing lipophilicity of the alcohol used. me permeation rate of the drug from those systems was shown to be governed by penetration-enhancing effects of the oily base and alcohol, and the penetration of the alcohol itself through the skin.     

结构陶瓷的高温疲劳强度衰减理论

提出了陶瓷材料疲劳强度衰减理论并由此导出了各种疲劳关系式。建立了疲劳基本方程ｄσ＿ｒ／ｄ＿ｉ＝一Ａσ（ｔ）￣ｎｔ￣（－ｍ），得出了疲劳寿命公式Ｔ＝Ｍ（σ＿０－σ）／Ａσ￣ｎ（静疲劳时Ｍ＝１，连续增载疲劳时Ｍ＝ｎ＋１，循环疲劳时Ｍ＝（ｎ＋１）／（１＋Ｒ＋Ｒ￣２＋……＋Ｒ￣ｎ），逐级加载时，并导出不同疲劳方式下疲劳寿命间的关系。同时，用多种Ｓｉ＿３Ｎ＿４材料在高温中作了论证试验，结果与理论一致。     

A neural network-based power system stabilizer using power flowcharacteristics

A neural network-based power system stabilizer (neuro-PSS) is designed for a generator connected to a multi-machine power system utilizing the nonlinear power flow dynamics. The use of power flow dynamics provides a PSS for a wide range of operation with reduced size neural networks. The neuro-PSS consists of two neural networks: neuro-identifier and neuro-controller. The low-frequency oscillation is modeled by the neuro-identifier using the power flow dynamics, then a generalized backpropagation-through-time (GBTT) algorithm is developed to train the neuro-controller. The simulation results show that the neuro-PSS designed in this paper performs well with good damping in a wide operation range compared with the conventional PSS     

Design of optimum signals for the simultaneous estimation of timedelay and Doppler shift

The problem of joint estimation of time delay and Doppler shift is considered from the point of view of the Wigner distribution of the signal. A very efficient method of obtaining the optimum signal with minimum estimation error based on the convexity of the design region is developed. Practical applications, however, require the signal to satisfy other constraints which present complications in acquiring the optimum signal. A design approach based on the method of simulated annealing is suggested to solve for the optimum signal under constraints. The performance of the signals so obtained is evaluated and compared with that of signals obtained by synthesis