静动应力作用下大连饱和黏土的剪切特性研究

针对人工制备的大连饱和黏土,在静应力与循环应力联合作用下进行了多组循环剪切试验,着重探讨了初始静力大小及加载速率对循环剪切变形特性的影响.试验表明静应力与循环应力作用下饱和黏土具有循环蠕变特性,总应变由初始静应变和循环蠕变两部分组成,其中循环蠕变主要受循环应力幅值、初始静应力大小及其加载速率的影响,循环蠕变的逐次增加量...     

一种重要的固体稳定同位素平衡分馏计算方法——Partial Hessian Vibrational Analysis (PHVA)方法

Partial Hessian Vibrational Analysis(PHVA),中文翻译为"部分力常数矩阵振动分析(方)法"。本文综述了PHVA的思想、原理、数学表达、研究历史、实现及其在同位素分馏计算中的前沿研究成果及存在的争议。     

基于格网索引的点目标捕捉算法

传统的从离散点中捕捉其中一点的算法实现存在精确度低、重复计算耗时、难度大的不足,从而增加了捕捉的计算量而影响性能。本文介绍了一种基于格网索引的点目标捕捉算法,通过对点群的格网划分,行列号的计算与Morton码的获得,建立空间索引表、实体索引表与点目标的存储单链表,成功完成点目标的捕捉。     

Macroscopic diffusivity in concrete determined by computational homogenization

Effective moisture and chloride ion diffusivity coefficients for concrete are determined by computational homogenization, where concrete is modeled on the mesoscale as a heterogenous three‐phase composite material. By imposing moisture and chloride ion gradients on a representative volume element, effective macroscale properties are obtained through finite element analysis. A parametric study of the effects of the ballast content was carried out. The numerical results correspond well with an estimate of the Hashin–Shtrikman type available in the literature. The computational homogenization strategy proposed here also includes the interfacial transition zone, and its influence on the effective diffusivity coefficients is assessed. Copyright © 2012 John Wiley & Sons, Ltd.     

Part 4 Technology and the future of GIS and spatial analysis

Geographical Information Science is essentially computational geography and has its own research program, namely all aspects of formal models for spatial natural processes and the interaction of humans with the environment in space and time. This is not a question of technology and technology-related research; but technology influences what questions can be researched effectively. Collection of data in the field and the simulation of field experience through Virtual Reality are just two questions of how spatial reality and human experience are linked. The focus on human spatial cognition is similarly found in software engineering for interoperable Geographic Information Systems.     

完全非内插半拉格朗日格式在一维 Burgers方程及二维浅水波方程上的应用

在作者过去提出的完全非内插半拉格朗日格式的基础上,针对半拉格朗日格式由于内插带来预报场人为的光滑性问题,进一步发展了这种计算格式,证明了此格式的计算稳定性。为检验这种新的计算格式的性能,在一维和二维问题上进行了应用。在一维问题中采用了一维无粘Burgers方程（方程中有突变点）;二维问题采用了浅水波方程,同时将这些计算结果与Ritchie方案及欧拉方案或一般半拉格朗日内插方案的计算结果进行了比较,发现新格式消除了内插和预报场的人为光滑,并且计算精度有一定程度的提高,这为以后将此格式推广到全球谱模式打下了基础。     

Clumpy Substructures in Globular Cluster Tidal Tails

In this paper, we present some preliminary results of numerical simulations of a globular cluster orbiting in the inner region of a triaxial galaxy. The formation and evolution of tidal tails around the cluster is discussed, together with their morphology, which shows clumpy substructures as observed, for example, in the galactic globular cluster Palomar 5.     

秦皇岛市生活气象指数预报技术初探

针对秦皇岛市建设康养城市的气象服务需求,通过对秦皇岛地区近50年气候舒适度的深入研究,运用天气学、应用气象学原理,采用数学统计方法,分析了秦皇岛地区多种生活气象指数对气象要素的敏感度和依从性,确定了关键影响因子。综合考虑相关显著的气象要素,利用因子相乘等方法,建立了舒适度、户外游泳、海上观光、海钓、蓝天和户外锻炼等与秦皇岛居民生活息息相关的生活气象指数公式。采用文献检索法、访谈法、专家打分法等方法,基于人体安全、健康和舒适的角度,参考秦皇岛市近50年气候舒适度的研究结果,以及相关灾害性天气预报、预警发布标准等,根据人体适宜程度进行了单因子阈值确定。考虑专业气象服务实际需求,根据实用性原则,对指数计算结果进行了气象指数的分级,提出了基于气象视角的建议。依据气象台、海洋气象台等相关部门影响因子的预报结果,可计算出生活气象指数数值,根据等级划分标准,制作生活气象指数等级预报。生活气象指数预报指导人们更合理地安排生活和运动,既提高了人们的生活质量,也扩大了气象服务领域,有利于取得更高的社会效益和经济效益。     

高铁沉降监测网点稳定性判断指标研究

提出了高铁沉降监测起算基准点稳定性判断指标,根据误差传播理论提出指标,给出了如何根据基准点稳定性判断指标确定稳定的基准网平差起算点方法,并通过武咸城际铁路基准网复测数据进行了计算分析验证。     

Digital Data-Centric Geography: Implications for Geography's Frontier

The debate regarding geographic information systems (GIS) as tool, toolbox, or science still lingers in geography departments and among geographers. Analysis of geographic information is a vital component of decision making among business, governments, researchers, and academics. GIS users, geographers and nongeographers alike, use and benefit from problem-solving methods in numerous fields and contexts, making the use of GIS and the core competencies associated with using GIS a topic of intense debate. Complicating this ongoing discussion is the rise of data-centric approaches to research in geography that further expand the capabilities of spatial analysis and add to the expected knowledge of a GIS user and analyst. Building on a panel discussion at the 2016 American Association of Geographers (AAG) annual meeting, as well as informal dialogues on Twitter and other social media platforms that navigate this issue in academics and industry, this article explores how skills in research computing and programming operate in geography and GIS, especially given the rise of data-centric approaches to research in these realms. Some topics, like the costs and benefits of open and closed source software, are familiar from previous discussions in geography and GIS. Others, though, like the reward structures and recognition for computing skills or programming ability, have not been widely considered given the current landscape.