一种新的状态转移模型

本文提出了一种用于计算机协议分析与验证的新状态转移模型——复合转移模型,这种模型的优点是可以弥补目前所通用的混合模型的2点不足。1.验证混合模型时,需要使用2种完全不同的方法,这不利于验证的自动化实现;2.混合模型中的转移模型部分与语言模型部分联系较弱,在验证中其相互影响得不到充分体现;本文叙述了复合模型的构成,与混合模型之间的转换,及其分析方法。     

铁电体中电畴壁的经典行为

本文讨论铁电体中电畴壁在扰动力作用下的运动,指出在常力作用下畴壁有经典非牛顿粒子的行为.每一种铁电材料存在着与温度有关的本征频率,在周期性外电场作用下,畴壁作振动,但振幅不是常数,当外场频率接近本征频率时,振幅趋于稳定极大值,即发生共振,使电矩增加.     

带斯塔克势的非线性Schroedinger方程的整体解

研究带斯塔克势的非线性Schroedinger方程，证明了解在H^1（R^n）中整体存在的充分条件，并且该条件与方程的基态解密切相关。     

A light-harvesting siphonax-anthin-chlorophyll a／b-protein complex of marine green alga, Bryopsis corticulans

A light-harvesting chlorophyll a/b-protein complex (LHCP) was isolated directly from thylakoid membranes of marine green alga, Bryopsis corticulans, by two consecutive runs of liquid chromatography. The trimeric form of the light-harvesting complex has been obtained by sucrose gradient ultracentrifugation. The result of SDSPAGE shows that the light-harvesting complex is composed of at least five apoproteins in which a protein with apparent molecular weight of about 31 kD was never found in the major light-harvesting complex (LHC II ) from higher plants. The isolated Bryopsis corticulans light-harvesting complex contains a specific carotenoid, siphonaxanthin, as well as chlorophyll (Chl) a, Chl b, neoxanthin and violaxanthin. Siphonaxanthin which is present in the light-harvesting siphonaxanthin-chlorophyll a/b-protein complex of Bryopsis corticulans is responsible for enhanced absorption in the blue-green region (530 nm). Efficient energy transfer from both siphonaxanthin and Chl b to Chl a in Bryopsis corticulans LHCP, which has similar absorption and fluorescence emission spectra to those of the lutein-chlorophyll a/b-protein of higher plants, proved that molecular arrangement of the light-harvesting pigments was highly ordered in the Bryopsis corticulans LHCP. The siphonaxanthin-chlorophyll a/b-proteins allow enhanced absorption of blue-green light, the predominant light available in deep ocean waters or shaded subtidal marine habitats.     

树木年轮分析在环境监测中的应用进展

阐述树木年轮在环境中应用的基本原理，综合分析树木年轮分析在环境监测中应用的发展历程和最新进展，通过研究实例扼要综述树木年轮在大气痕量金属沉降的监测、水体和土壤重金属沉降的监测、有机污染物的推断和人工合成放射性元素的调查研究中的重要领域，探讨树木年轮研究存在的不足、难以解决的问题及可能改进的途径。认为今后利用树木年轮研究环境变化的重要领域是树木逆境条件下生理特性的基础理论研究、污染元素时空分异规律的研究、污染元素进入树木体内动力学过程及其与环境相关性的研究，以及多学科交叉、与其他环境信息源记录的比较研究。     

龙眼暖春"冲梢"气象指标及其发生规律研究

利用广西玉林农业气象试验站1987～1992年及2001-2002年的龙眼“冲梢”观测记录资料及同期的气温、风向资料，确定龙眼暖春“冲梢”的气象指标，然后根据这些指标，选取广西龙眼主产区40个气象观测站点1961～2000年2～3月日平均气温、日最高气温以及南风天数资料，分析广西龙眼主产区春季暖害的时空分布特征，提出采用选择龙眼暖春“冲梢”少的区域发展龙眼；根据气候灵活应用调控技术，推行平衡施肥技术和药物控梢的方法来防抗龙眼暖春“冲梢”。     

Finite Eement Facture Aalysis of the Main Arm of Tower Cranes with the 3-D Cracks

In this paper the local solutions of displacement fields in front of three-dimensional cracks are introduced and a new singular element of three-dimensional crack problems is constructed, and a new method for calculating stress intensity factors of three-dimensional crack problems is presented. With the present method, the structural strength of with longitudinal closed cracks under axial tensions is analyzed. It is possible for the crack to propagate because there are ring tensile stresses near joints of the main arm in tower cranes under axial press stresses. The stress and the stress intensity factor are calculated at joints on the main arm of tower cranes. Influences of welding residual stress on stress intensity factors and stresses are discussed.     

Positional distribution of fatty acids on the glycerol backbone during the biosynthesis of glycerolipids in Ectocarpus fasciculatus

The biosynthesis of glycolipids in E. fasciculatus was studied by ¹⁴C label and chase. The fatty acids in sulphoquinovosyl diacylglycerol (SQDG) were almost 16-car- bon and 18-carbon ones. In addition to the two fatty acids, monogalactosyl diacylglycerol (MGDG) and digalactosyl diacylglycerol (DGDG) contained 8.5 mol% and 31.0 mol% of eicosapentaenoic acid (20∶5), respectively, and this fatty acid was usually distributed in the sn-1 position of the glycerol backbone. When plants were incubated with [2-¹⁴C] acetate, differences existed in the positional distribution of the labeled fatty acids in sn-1 and sn-2 among the three glycerolipids. In SQDG, ¹⁴C-labeled fatty acids were distributed uniformly in the sn-1 and sn-2 positions. In DGDG, ¹⁴C-labeled fatty acids were mainly distributed in the sn-2 position. In MGDG, the radioactivity of fatty acids in sn-1 position was far greater than that in sn-2 position after a 30 min pulse label, and the difference in radioactivity between the two positions decreased rapidly. The above results indicated that differences in the positional distribution of ¹⁴C-labeled fatty acids between sn-1 and sn-2 positions might be related to 20∶5 and the biosynthesis of DGDG. Our results also suggested that E. fasciculatus had the same DGDG biosynthetic pathway as that in higher plants and galactosyl transferase was selective for MGDG.