Analysis of the compression behavior of artificial lumpy composite materials

The landfills are dumped without any compaction and have a relatively open structure, which is similar to that of the granular materials. However, the original dumped material might be gradually transformed into a lumpy composite structure because of the influence of the climate. As a result, the lumps are randomly distributed in the reconstituted soil. In the presented study, the compression behavior of the lumpy composite soils was analyzed within the homogenization framework. Firstly, the volume of the composite soil was divided into four individual components. The inter‐lump porosity was introduced to account for the evolution of the volume fractions of the constituents, and it was formulated as a function of the overall porosity and those of its constituents. A homogenization law was then proposed based on the analysis of the lumpy structure together with a numerical method, which gives a relationship for tangent stiffnesses of the lumpy soil and its constituents. Finally, a simple compression model was proposed for the composite lumpy material, which incorporates both the influence of the soil structure and the volume fraction change of the reconstituted soil. The predictions of the model were validated against the test results, and the stress distribution within the lumpy composite was assessed. Copyright © 2016 John Wiley & Sons, Ltd.     

Conceptualizing leakage and storage contributions from long open interval wells in regional deep basin flow models

Deep basin aquifers are increasingly used in water‐stressed areas, though their potential for sustainable development is inhibited by overlying aquitards and limited recharge rates. Long open interval wells (LOIWs)—wells uncased through multiple hydrostratigraphic units—are present in many confined aquifer systems and can be an important mechanism for deep basin aquifers to receive flow across aquitards. LOIWs are a major control on flow in the deep Cambrian–Ordovician sandstone aquifers of the upper Midwest, USA, providing a source of artificial leakage from shallow bedrock aquifers and equilibrating head within the sandstone aquifers despite differential pumpage. Conceptualizing and quantifying this anthropogenic flow has long been a challenge for groundwater flow modellers, particularly on a regional scale. Synoptic measurements of active production wells and well completion data for northeast Illinois form the basis for a transient, head‐specified MODFLOW model that determines mass balance contributions to the region and estimates LOIW leakage to the aquifers. Using this insight, transient LOIW leakage was simulated using transiently changing K_V zones in a traditional, Q‐specified MODFLOW‐USG model, a novel approach that allows the K_V in a cell containing a LOIW to change transiently by use of the time‐variant materials (TVM) package. With this modification, we achieved a consistent calibration through time, averaging 19.9 m root mean squared error. This model indicates that artificial leakage via LOIWs contributed a minimum of 10–13% of total flow to the sandstone aquifers through the entire history of pumping, up to 50% of flow around 1930. Removal from storage exceeds 40% of flow during peak withdrawals, much of this flow sourced from units other than the primary sandstone aquifers via LOIWs. As such, understanding the timing and magnitude of LOIW leakage is essential for predicting future water availability in deep basin aquifers.     

A Kinematical Calibration of the Galactocentric Distance

1 INTRODUCTION The distance to the Galactic center R0 is a fundamental constant for astronomy and astrophysics. Most determinations of astronomical quantities are directly connected with the Galactic distance scale, e.g., the rotational speed of our Galax…     

疏散星团的质量分层

对疏散星团质量分层的有关问题做了简要的评述,包括空间质量分层和速度质量分层的表现形式和探测途径,质量分层形成机制的研究现状.最后概要介绍了2MASS测光资料对探讨疏散星团质量分层效应的作用.     

基于开源CMS系统的网站群设计

内容管理系统(CMS)是四川省农村经济综合信息中心及其所辖省市县乡4级信息员的日常业务所依赖的工作系统,代表了中心业务技术的主流。在以开源Java CMS业务化应用为目标的进程中,完成了Windows向Linux、C#向Java、数据库向CMS的转型;促成了元数据技术在内容分类标准、内容类型定义中的应用;在CMS中的角色概念的作用下形成了系统管理员、开发团队、内容管理员的组织架构和省市县乡门户管理的组织形态;在CMS中的内容控制概念的作用下实现了虚拟文件系统、采编发工作流程、多站点内容管理;在门户技术的作用下实现了模板管理、页面内容等功能。最终有效实现了四川省气象网站、四川农村信息网以及21个分中心网站的高效管理。     

在空间数据库课程中采用开源软件实验的教学实践

对比分析了国内外空间数据库课程现状。针对开源地理空间信息软件体系在空间数据库实验课程中的教学特点,探讨了开源软件应用于空间数据库课程实验的教学实践,提出了分阶段实验教学方法,在实际教学中取得了好的效果。     

Analysis of the mass functions for three open star clusters

Based on our own observational data, we have constructed the mass functions for three young-and intermediate-age Galactic star clusters, Trumpler 2, NGC 7243, and NGC 1513. Their mean slopes Γ fall within the Scalo range: Γ = ?1.7 ± 0.5 for 1M _⊙ < M < 10M _⊙. For each of the clusters, we also analyze the mass distribution of their members as a function of the distance to the center. Noticeable mass segregation in the sense of massive-star concentration toward the cluster center has been detected in Trumpler 2 and NGC 7243. Deviations from rectilinearity in the same direction are observed at log M ≈ 0.41 in each of the three zones of Trumpler 2, which can be interpreted as a small dip in the mass function. We have found peculiarities in NGC 1513 that are difficult to explain by observational selection alone. Comparison of our results with similar studies reveals a similarity in radial Γ distribution for NGC 7243 with h Per and for Trumpler 2 with IC 1805.     

利用概率松弛法的城市路网自动匹配

多源空间数据匹配是空间数据集成与互操作,变化检测与数据更新的重要前提。路网数据匹配在导航、智能交通和基于位置服务等领域具有重要的研究意义和实用价值。本文提出一种基于概率松弛方法的城市路网自动匹配方法,该方法首先通过路段间几何差异性估算候选路段的初始概率,然后根据邻接候选匹配路段的兼容性不断更新原概率矩阵直到收敛于某一极小值。最后基于收敛的概率矩阵计算各候选路段的结构相似性,并通过设定相应的规则选取和提炼1: 1, 1: M和M: N匹配对。实验选取中国武汉,瑞士苏黎世地区的OpenStreetMap数据与导航数据进行匹配算法的验证。结果表明：本文算法对非刚性偏差较大的路网数据能达到较高精度,不存在匹配方向性问题,且能够识别1: 0, 1: M和M: N匹配。     

基于CORBA的开放式GIS构建

现代信息技术的变革使网络技术与GIS的结合日益紧密 ,从而促进了开放GIS技术的研究。开放式GIS研究的目的是提供一套具有开放界面规范的通用组件 ,开发者根据这些规范开发出交互式组件 ,从而实现不同种类地理数据和地理处理方法间的透明访问。文中主要讨论了基于CORBA的开放式GIS的网络系统构建技术 ,使用户能在分布式的多服务器且存在异构的网络环境中共享地理空间数据。