TSINGHUA SCIENCE AND TECHNOLOGY

Vol.5,\ No.2,\ June\ 2000

CONTENTS

PHYSICS

Wave vector   dependent Tunneling Transmission Characteristics  in Periodic and Quasiperiodic Semiconductor Superlattices          GUO Yong  WANG Hao  GU Binglin 121-127

Neutron rich    104,106,108 Mo Isotopes in the Generalized Collective Model               LI Ming, M.Sakhaee, ZHU Shengjiang, et al 128-131

Dynamical Suppression of Magnetic Tunneling                MAO Juanjuan  WANG Xiaobing, Rong, et al 132-136

Supersymmetry and the Dirac Equation with Vector and Scalar Coupling Potentials               TU Changcun, ZHU Weibin,  RUAN Dong 137-139

MATHEMATICS

An Extension of Sobolev's Theorem        WANG Xiaoqun 140-144

Volume Dispersion of Point Sets and Quasi Monte Carlo Methods WANG Xiaoqun 145-149

Fundamental Unit System and Class Number for Real Number Fields of  Type (2,2,2)              WANG Kunpeng ZHANG Xianke 150-153

A Functional Equation Governing the Motion of a Compressible  Fluid Flow  M.H.Mahmoud 154-158

CHEMISTRY AND CHEMICAL ENGINEERING 

Cytotoxic Compounds from  Zanthoxylum Americanum                JU Yong ZHAO Yufen Still Cecil C et al 159-162

Synthesis of OPhosphorylated Oligopeptides Using  Phosphoramidite              LI Yanmei, ZHAO Yufen,  Waldmann Herbert 163-166

Synthesis and Properties of Some Novel Liquid Crystals: Chiral (4 alkoxy 2,3 difluorobenzoyloxy) 4 biphenyl  Carboxylates            HU Gang TANG Hong XU Shouyi 167-171

Crosslinking of PVA Pervaporation Membrane by Maleic Acid          MENG Pingrui CHEN Cuixian YU Lixin, et al 172-175

Synthesis and Absorption Characteristics of Two Infrared         Cyanine Dyes LI Bin, TANG Liming,  DONG Hanpeng, et al 176-179

INFORMATION SCIENCE AND TECHNOLOGY 

Variable Bandwidth Smoothing Based on Cluster Analysis                ZHOU Xiaobo ZHOU Lei ZHANG Xianda 180-182

Multiple Face Location Using Motion Information                            YUAN Chao ZHANG Changshui 183-186

Convergence Analysis of Forgetting Gradient Algorithm by Using Martingale Hyperconvergence Theorem                      DING Feng, YANG Jiaben, XU Yongmao 187-192

Data Filtering and Statistical Process Modeling                       WANG Jingchun, JIN Yihui,  Morris Julian 193-200      

Sensor Fault Tolerant Generic Model Control for Nonlinear  Systems                       XIE Xiaoqing ZHOU Donghua JIN Yihui 201-207

Epitaxy of SiGe Layers by Ultrahigh Vacuum Chemical Vapor  Deposition                 LUO Guangli, CHEN Peiyi,  QIAN Peixin, et al 208-210

Efficient Heuristic Variable Ordering of OBDDs                          LONG Wangning MIN Yinghua BIAN Jinian, et al 211-216

Semantic Model for Voice Controlled Telephone Dialing and  Inquiry Systems                    ZHANG Jianping, WANG Zuoying 217-221

HYDRAULIC AND HYDROPOWER ENGINEERING  

Comparison of Energy Dissipation with and without Aerators                      NIE Mengxi 222-225

Computing Depth averaged Flows Using Boundary fitted  Coordinates and Staggered Grids                 HONG Yiping ZHOU Xueyi CHEN Yongcan, et al 226-230

Numerical Analysis of the Mixing Zone for a Vertical Discharge into a Tidal River                         LI Yuliang, ZHOU Xueyi,   HU Tao 231-235