A study of the static and dynamic properties of side-chain liquid crystalline polymers in low molar mass mesogens

The static and dynamic properties of solutions of a side chain polysiloxane liquid crystal polymer have been studied in a cyanobiphenyl nematic host as a function of concentration and temperature. Refractive index measurements were carried out on aligned samples and the data used to determine the macroscopic order parameter, S, using Haller's method. Photon correlation spectroscopy has been used to measure ($\text{k}{}_{22}\text{γ}{}_1$) for the pure nematic solvent and the solutions. From these measurements it appears that the static properties vary slowly and linearly with increasing polymer concentration whilst the dynamic or viscoelastic properties change markedly. This change has been attributed to γ₁, the twist viscosity, and the results have been discussed in terms of the function of the siloxane polymer backbone.     

A method for quantifying cell size from differential interference contrast images: validation and application to osmotically stressed chondrocytes

An automatic image analysis method was developed to determine the shape and size of spheroidal cells from a time series of differential interference contrast (DIC) images. The program incorporates an edge detection algorithm and dynamic programming for edge linking. To assess the accuracy and working range of the method, results from DIC images of different focal planes and resolutions were compared to confocal images in which the cell membrane was fluorescently labelled. The results indicate that a 1‐µm focal drift from the in‐focus plane can lead to an overestimation of cell volume up to 14.1%, mostly due to shadowing effects of DIC microscopy. DIC images allow for accurate measurements when the focal plane lies in a zone slightly above the centre of a spherical cell. In this range the method performs with 1.9% overall volume error without taking into account the error introduced by the representation of the cell as a sphere. As a test case, the method was applied to quantify volume changes due to acute changes of osmotic stress.     

High temperature low cycle fatigue

Fatigue at high temperature is a complex phenomenon as it is influenced by a number of time-dependent processes which become important at elevated temperatures. These processes include creep, oxidation, phase instabilities and dynamic strain ageing (DSA), acting either independently or synergistically influence fatigue behaviour, often lowering the fatigue life. Current design approaches employ linear summation of fatigue and creep damage with suitable factors on permissible damage to take care of uncertainties in interaction between cyclic and time-dependent processes. It is, therefore, important to develop a deeper understanding of the processes that occur during high temperature fatigue so that realistic life predictions could be made. Results on the high temperature fatigue behaviour of austenitic stainless steels, ferritic steels and nickel base alloys are presented here. The important mechanisms of interaction of high temperature time-dependent processes with fatigue under various conditions are discussed in detail. Emphasis is placed on cyclic stress response, fatigue life, deformation substructure and fracture behaviour. This is followed by a review of important life prediction techniques under combined creep-fatigue loading conditions. Life prediction techniques considered here include linear damage summation, strain range partitioning, ductility exhaustion approach, frequency modified and frequency separation methods, techniques based on hysteresis energy and damage rate models, and methods based on crack-cavitation interation models.     

大集中后数据调整智能化处理的实现

文章简单介绍了INFORMIX关系数据库动态RDSQL语句的使用方法以及利用动态RDSQL语句成功开发的中国建设银行湖南省分行智能帐务调整模块的设计方法。     

连拱坝交叉模态综合法的完备性

对笔者提出的连拱坝动力特性计算的子结构交叉综合法的正确性进行了证明．利用证明子结构子模态向量组成的线性空间是完备的基础上，说明当交叉子结构中所取的截尾模态趋向于完备时，其结果等同于整体计算，并表明近似计算将收敛于正确的结果．     

Neural networks modeling signal responses and taxol production of cultured Taxus chinensis cells induced by bio-elicitor

Quantitatively describing the signal transduction process is important for understanding the mechanism of signal regulation in cells, and thus, poses both a challenge and an opportunity for chemical and biochemical engineers. An artificial neural network (ANN), in which we took the signal molecules as neural nodes, was constructed to simulate the generation of active oxygen species (AOS) in Taxus chinensis cells induced by a bio-elicitor. The relative contents of AOS in cells predicted by the ANN model agreed well with the experimental data and three notable stages of AOS increase were observed from the 3D figure of AOS generation. The robustness of AOS trajectories indicated that signal regulation in vivo was an integral feedback control model that ensured the adaptation of Taxus chinensis to environmental stress. The artificial neural network was able to predict taxol production as well as determine the optimal concentration of oligosaccharides needed for it.     

软土路基沉降计算新方法及应用研究

介绍了一种动静结合的软土路基沉降计算新方法,并将该方法应用到动力固结路基处理工程实践中.对软土路基沉降进行了计算,通过将沉降计算值与实测值进行比较,验证计算方法的可行性.计算结果显示,路基断面总沉降量计算值为669.6 mm,实测值为675 mm,两者比较相近,说明该沉降计算方法是可行的.     

工程结构动态特性智能优化设计研究

本文针对在传统结构优化设计中，优化过程复杂和费时的问题，采用神经网络的智能算法对结构进行动态优化设计，并给出了具体的设计方法。以门座起重机筒型支柱结构为例，应用此方法对其进行了动态优化设计计算，从而证明了该算法的有效性。     

动态信号分析系统的进展及应用

本文综述了动态信号分析仪器与系统的发展,并综合介绍了双通道动态信号分析仪的构成、性能与指标,以及由动态测量、数据采集、信号处理等硬件与相应软件组成的多通道动态信号分析系统的进展.     

奇异值分解对非定常约束多体系统的动力学分析

通过对约束方程的雅可比矩阵进行奇异值分解，定义组合坐标，从拉格朗日第一类方程出发，建立了非定常约束多体系统的纯微分方程，给出了动力学数值分析的过程，最后举了一个算例。