汉文-维吾尔文双语语料库中段落对齐技术研究

随着信息技术的普及与推广,双语电子文本资源呈指数形式增长,这给构建大规模双语语料库提供了可能．双语对齐作为语料库加工过程中的关键技术,已经引起研究者的高度重视．针对目前可收集到的双语资源大都没有做到段落对齐,本文提出了基于回车符段落对齐基础上的多层次分段对齐思想,充分利用汉文-维吾尔文双语文本中的语言特点,根据双语文本中的数字信息,找出互为译文的句对,从而达到高质量的段落对齐目的．     

CRACK FACE CONTACT PROBLEM ANALYSIS USING THE SCALED BOUNDARY FINITE ELEMENT METHOD

比例边界有限元侧面上有任意荷载时,将侧面载荷分解成关于径向方向局部坐标的多项式函数的和,推导给出了考虑侧面载荷存在的新型形函数,并基于该形函数推导了刚度矩阵和等效节点载荷列阵.首次对比例边界有限元法求解裂纹面接触问题进行了研究,运用Lagrange乘子引入接触界面约束条件,推导给出了比例边界有限元求解裂纹面接触问题的控制方程.将裂纹面单元分为非裂尖单元和含有侧面的裂尖单元.在非裂尖单元中的裂纹面,裂纹面作为多边形单元的边界,边界上的接触力可等效到节点上,通过在节点上构造Lagrange乘子,采用点对点接触约束进行处理.对于含有侧面的裂尖单元,在整个侧面上构造Lagrange乘子的插值场,采用边对边接触约束进行处理.对三个不同的接触约束状态下的算例进行了数值计算,通过与解析解及有限元软件ABAQUS计算结果的对比,验证了本文提出的比例边界有限元点对点和边对边接触求解裂纹面接触问题的精确性与有效性.     

Infrared absorption spectra of Aerosol-OT homologous sodium dialkylsulfosuccinates and the effect of crystal polymorphism on the environment of the succinate segment

A homologous series of sodium dialkylsulfosuccinates, which are straight-chain analogues of Aerosol-OT with various chain lengths (dimethyl, diethyl, dibutyl, dihexyl, diheptyl, dioctyl, didecyl, diundecyl and didodecyl), has been synthesized. In order to assign the IR bands of the CH₂ scissoring and CH deformation modes of the succinate segment, sodium dideuteratedmethylsulfosuccinate and sodium dideuteratedethylsulfosuccinate have also been synthesized. IR absorption spectra have been recorded for these mono-, di- and multihydrate samples in the solid state. In particular, IR bands in the 1250–1500 cm⁻¹ region have been compared for sodium dimethylsulfosuccinate, sodium diethylsulfosuccinate and sodium diheptylsulfosuccinate, whose crystal structures are known. The CH₂ scissoring and CH deformation modes of the succinate CH₂-CH portion strongly depend upon the environment of hydration and on the length of the hydrocarbon portions. Received: 26 April 1999 Accepted in revised form: 15 June 1999     

THERMALLY STIMULATED SHAPE MEMORY BEHAVIOR OF(ETHYLENE OXIDE-BUTYLENE TEREPHTHALATE)SEGMENTED COPOLYMER

The thermally stimulated shape memory behavior of ethylene oxide-butylene terephthalate (EOBT) segmentedcopolymers with different soft segment molecular weight and hard segment content was investigated. The deformationrecovery ratio R_f of the EOBT samples increases with the soft segment molecular weight and the hard segment weightcontent, while the average overall deformation recovery speed V_r increases with the hard segment content. The temperatureof maximum deformation recovery speed (T_M) is determined by the melting temperature of the soft segment crystals and thestability of the crystallized hard segment domains.     

The alternating segment crank-nicolson method for solving convection-diffusion equation with variable coefficient

IntroductionThenumericalmethodsforsolvingtheconvection_diffusionequationwithvariablecoefficientisappliedwidelyintheproblemsofconductionofheatininhomogeneousmediumandionicdiffusion .Forexample ,thetransmissionofthepaleoheatoftheearth’sinterioronthenumericalsimulationforevolutionaryhistoryofbasinisoneoftheseproblems,hencethestudyoftheparallelnumericalmethodoftheproblemanditsapplicationisveryimportantforthedevelopmentofmodernscienceandtechnology .D .J.EvansandZhangBao_linetal.haveobtainedmanyr…     

变系数对流-扩散方程的交替分段Crank-Nicolson方法

对Saul'yev型格式中的对流项构造了一种新的离散化逼近形式,进而给出了变系数对流-扩散方程的Crank-Nicolson方法.这个方法是绝对稳定的.数值实验表明该方法并行性好,精度高,宜于直接在并行计算机上使用.     

THE BENDING OF THIN RECTANGULAR PLATES WITH MIXED SUPPORTED SEGMENTS OF STRAIGHT EDGES

ＴＨＥＢＥＮＤＩＮＧＯＦＴＨＩＮＲＥＣＴＡＮＧＵＬＡＲＰＬＡＴＥＳＷＩＴＨＭＩＸＥＤＳＵＰＰＯＲＴＥＤＳＥＧＭＥＮＴＳＯＦＳＴＲＡＩＧＨＴＥＤＧＥＳＣｈｅｎＬｉ－ｚｈｉ（陈立志）（ＱｉｎｈｕａｎｇｄａｏＰｏｒｔＡｕｉｈｏｒｉｔｙ,Ｑｉｎｈｕａｎｇｄａ...     

鼠脑钠通道Ⅰ的IS3片段的溶液法合成

采用本甲酸甲酯作为α－羧基的暂时性保护基,以片段缩合的方式合成了疏水性多肽──鼠脑钢通道Ⅰ的IS3片段,利用高效液相色谱对其进行了纯化,并通过了氨基酸组成分析和快原子轰击质谱鉴定.     

Polymer Chain Dynamics Predicted by n-Renormalized Rouse Models: Numerical Studies

Features of the renormalized and twice renormalized Rouse models were examined numerically. Based on numerical evaluations of the generalized Langevin equation in renormalization approaches, nonexponential normal mode autocorrelation functions were derived, that can be described over two orders of magnitude by stretched exponential functions. The mode number dependence of the stretching parameter was evaluated. The consequences of the nonexponential correlation functions on dynamical properties are discussed. As a basis for predictions for the behavior of diffusion and spin-lattice relaxation dispersion, the time dependence of the mean-squared segment displacement and of the autocorrelation function of the segment tangential vector, respectively, were obtained taking into account finite chain lengths.