塑料充模流动粘性模型研究

对多种塑料在不同温度下的剪切速率一稳态剪切粘度数据进行Cross粘性模型参数拟合，得到了表征材料粘度的模型参数(B，Tb，τ^*，n)。其拟合效果良好，能较准确地描述塑料熔体在一定剪切速率和温度范围内的粘流特性，为工程计算和塑料熔体模流分析提供了数据支持。结果表明，该方法有较广泛的适用性。     

Model for drying during fluidized-bed combustion of wet low-rank coals

An unsteady state heat conduction model with a convective boundary condition is proposed for the drying of low-rank, high-porosity coals, such as lignites, during fluidized-bed combustion. The drying front is assumed to be the receding surface of a wet core. The solution technique for this moving boundary problem is based on the heat balance integral approach with immobilization of the moving boundary by a change in space variable. The governing cubic equation describing the drying curve in dimensionless form may be solved easily by the Newton—Raphson method. The model predictions are compared with experimental data for Mississippi lignite with excellent agreement. A correlation for estimation of total drying time is proposed. The temperature profiles obtained may be used for the study of the coupled drying and devolatilization in fluidized-bed combustors. The profiles could also be of importance in the study of formation of fissures/cracks in lignites subjected to intense heating conditions encountered during fluidized-bed combustion.     

油水乳化液流变性研究进展

综述了油水乳化液流变性研究进展，介绍了目前国内外乳化液流变性的研究情况、乳化液的流变模式及乳化液流变性的评价方法。乳化液的剪切应力-剪切速率关系明显受油滴尺寸的影响，在含油量一定时，表观黏度随油滴尺寸的减小而增加。绝大多数乳化液在低剪切速度下(低于50s^-1)，呈现剪切变稀行为；在剪切速率超过1000s^-1时呈现牛顿行为。高含水原油的视黏度是温度、含水率以及剪切速率的函数。介绍了乳化液的3种流变模式，并给出了流变性评价方法实例。提出了油水乳化液流变性研究的发展方向。     

基于改进的BASS模型的服装产品生命周期研究

为提高服装的销售预测准确度,通过产品的生命周期曲线模型,使得服装销售预测的定性分析与定量预测有机地结合在一起。针对目前服装产品生命周期曲线模型的局限性,引入改进的BASS模型,对服装产品生命周期进行研究。通过销售实例探讨改进的BASS模型用于描述服装生命周期的可行性,建立了以改进的BASS模型为基础的服装产品生命周期模型,并利用该模型对服装销售量做预测,取得了比其他模型更高的精度。     

Dynamic equivalent method of interconnected power systems with consideration of motor loads

The existing equivalent methods usually only deal with static load models and neglect the dynamic characteristics of loads such as induction motors.This paper presents a dynamic equivalent method which considers motor dynamics.At first,the clustering criterion of motor loads is given.The motors with similar dynamic characteristics are classified into one group.Then,reduction of motors in the same group is carried out.Finally,parameters of the equivalent motor are calculated and the equivalent system is thus...     

Conditional probability Markov chain simulation based reliability analysis method for nonnormal variables

Based on fast Markov chain simulation for generating the samples distributed in failure region and saddlepoint approximation(SA) technique,an efficient reliability analysis method is presented to evaluate the small failure probability of non-linear limit state function(LSF) with non-normal variables.In the presented method,the failure probability of the non-linear LSF is transformed into a product of the failure probability of the introduced linear LSF and a feature ratio factor.The introduced linear LSF wh...     

Alekseevskii-Tate revisited:An extension to the modified hydrodynamic theory of long rod penetration

The modified hydrodynamic theory of long rod penetration into semi-infinite targets was established independently by Alek-seevskii and Tate over forty years ago and since then many investigators contributed much to the development of the high speed penetration mechanics.However,in all the models proposed so far,the target resistance Rt is not well defined and usually determined by adjusting it until the predicted depth of penetration comes to an agreement with experimental data.In this paper,assumptions are...     

标准模型下群签名的批验证协议*

首次对标准模型下群签名的批验证协议进行了研究。利用小指数测试技术和双线性对映射的特殊性质,为目前效率较高的两个群签名方案按照多人签署相同消息和不同消息这两种情况,分别设计了相应的批验证协议。相较于单独验证,认证效率大大提高。     

Mathematical model of deoxidization with post stirring in a combined blowing converter

Dissolved oxygen in the steel at the terminal of the converter smelting process is the main cause for the formation of oxide inclusions, and the high terminal oxygen content worsens the steel cleanness. However, post stirring in a combined blowing converter can promote the carbon-oxygen reaction in the liquid steel and reduce the dissolved oxygen content at the terminal of the converter smelting process. Thus, the mathematical model of deoxidization in the post stirring process was obtained, and the rationa...     

基于模块化模型的自适应预失真技术

系统地比较和分析了OFDM传输系统里高功率放大器（HPA）预失真方法的优缺点,提出一种基于模块化模型的有记忆高功率放大器自适应数字预失真方法,该方法分别基于Wiener、Hammerstein和Wiener-Hammerstein模型各自构成一个有记忆HPA的自适应预失真器。从而避免了因分别估计Wiener-Hammerstein模型各个环节特性参数所带来的复杂性。使得有记忆高功率放大器的预失真设计变得简单了。