FEM on Coupled Hydromechanical Dynamic Response of Geogrid Reinforced Soil Retaining Wall

Geogrid reinforced soil retaining wall(GRSRW) is composed of panel,geogrid and soil,its coupled hydromechanical structural characteristics are increasingly emphasized in practice.In this paper,based on the characteristics of the reinforcement-soil interaction,the grogrid and soil around it with a definite thickness were regarded as a kind of composite material with strain-compatible condition.A saturated porous media model was introduced to simulate the soil and reinforcement-soil composite material hereby and the mathematic model for numerical analysis on structural characteristics of GRSRW was built up.The FEM equations were deduced from the standard Galerkin procedure,resolving these equations,we can gain the relevant dynamic response of saturated GRSRW.     

发动机用平板型空滤器流动阻力特性分析和改进

为减小平板型空滤器流动阻力以增大进气量,对平板型空滤器流动阻力特性开展了实验研究,获得了空滤器流动阻力随流量变化的规律和阻力构成成分。阻力随流量的增大而加速增大,滤芯阻力约占整个空滤器阻力的一半,入口流量为120 m 3/h时,总阻力为915.3 Pa,滤芯阻力为426.4 Pa。在实验获得滤芯阻力参数的基础上,提出采用多孔介质跃升模型对平板型空滤器内部流场开展三维数值仿真分析,结果表明,仿真结果与实验结果比较吻合,最大误差为5.67%。滤芯阻力同样约占整个阻力的一半,另一半阻力主要为出口处阻力,其余壁面阻力约占15%。最后,在实验和仿真分析的基础上,提出了改进模型并进行了仿真分析。结果表明,改进模型阻力有较大程度的下降,入口流量为120 m 3/h时,总阻力为588.2 Pa,较原始模型下降了32.2%;增大空滤器流通横截面积是减小阻力以增大进气量的有效手段,改进空滤器壁面的平滑性是补充措施。     

多孔介质水分运动的随机数值分析

采用van Genuchten-Mualem模型描述非饱和水力传导度和水分特征曲线,将模型中的3个参数作为随机场处理,联合运用Karhunen-Loeve展开和摄动方法,得到饱和非饱和水流的一个随机数值模型。应用该模型分析了介质随机参数的空间变异性对水头分布的影响,结果表明,水头标准差对介质参数的敏感程度由大到小依次为非饱和参数n、β、饱和水力传导度Ks,饱和带水头分布的变异性较非饱和带小。     

传统学习行为与网络学习行为比较研究

网络媒体的发展使得网络学习行为的研究成为热点。把传统学习行为与网络学习行为进行对比,比较两者的优缺点,找出网络学习的规律和特点,更好地服务于网络教学,提升教学水平。     

Characterizing Farmer Users and Nonusers of Mass Media as Channels of Agricultural Information in Benue State,Nigeria

This study characterized farmer users and nonusers of mass media as channels of agricultural information. A structured interview was used to obtain data from 316 randomly selected farmers in Benue State, Nigeria. The data were subjected to discriminant analysis and the following socioeconomic characteristics significantly differed at a 5% level of probability between users and nonusers of mass media (and their F-ratio values): education (6.30), income (5.12), gender (4.84), and socioeconomic status (4.83). Farmer users of mass media are therefore those who have good level of education, belong to a relatively high income bracket, and are typically male and of a relatively high socioeconomic status. Farmers’ socioeconomic characteristics should be considered in planning mass media usage in agricultural information dissemination.     

论网络媒介QQ在高校心理工作中的应用

本文主要讨论了如何构建"校、(院)系、班"三级心理工作QQ群、心理老师QQ咨询热线交互并存的心理工作网络体系,分析了如何利用QQ的各项功能开展学生心理日常工作和心理咨询服务等,以更大程度地提升学生心理健康水平。     

阜阳剪纸艺术在新媒体语境下的传播研究

纵观阜阳剪纸的渊源与现状,认为阜阳剪纸是一门古老的民间艺术,是安徽省国家级非物质文化遗产,在皖北地区颇具影响。然而阜阳剪纸"地域相承、亲缘相承、师徒相承"的传播方式,极大地限制了它的发展潜力。研究着重探讨了阜阳剪纸资源的整合方法与整合平台的建立,认为新媒体时代的到来为阜阳剪纸艺术的传播敞开了从区域到全国乃至世界的大门,因此,利用多种新媒体技术途径,对阜阳剪纸艺术进行资源整合,建立多媒体传播系统,使阜阳剪纸艺术在传承中得到更广泛的传播,显得尤为重要。     

大球盖菇菌丝生长适宜氮源研究

研究了不同氮源对犬球盖菇菌丝生长的影响，结果表明大球盖菇菌丝生长最适氮源是尿素，其适宜浓度是0．026％；蛋白胨次之，其适宜浓度是0．1％；硫酸铵最差。大球盖菇菌丝生长对氮源浓度极敏感，低浓度氮促进菌丝生长，高浓度氮显著抑制菌丝生长。     

The growth of tagestes erecta,petunia hybrida nana compacta and myosotis alpestris in a range of peat‐based container media

Abstract

The dry matter yield and nitrogen content of marigold (Tagestes erecta), petunia (Petunia hybrida nana compacta) and forget‐me‐not (Myosotis alpestris) plants growing in a range of peat‐based container media amended with different proportions of either sand, perlite, pumice, sawdust, bark chips or soil were studied under glasshouse nursery conditions.

Plant responses differed between species as manifested by their different correlations with measured moisture and aeration characteristics of the media. Marigold and petunia were adversely affected by excessive moisture content as demonstrated by their negative correlation with micropore water and container capacity. However, forget‐me‐not, being adapted to relatively high moisture regimes, responded adversely to increased aeration.     

高校图书馆数字媒体资源库的理论认识与模型构建

介绍高校数字化媒体资源库的本质涵义及其对于学习者的意义,设计了一个基于图书馆局域网环境下的数字媒体资源库模型,提出了图书馆数字化媒体资源库与学校各工作平台的对接模式.