Updating Numerical Models of Masonry Arch Bridges by Operational Modal Analysis

This article aims at presenting and discussing the strategies for updating the finite element numerical modeling of stone masonry arch bridges using operational modal analysis. The study comprehended three bridges: two old ones, the St. Lázaro and the Lagoncinha bridges, and a recently constructed bridge in Vila Fria, Portugal. Updating of the bridge models is performed by comparing the numerical and experimental modal parameters. Three-dimensional detailed numerical models are used to perform modal analysis of the bridges. Experimental modal identification of the bridges is based on the measurement of their acceleration responses during normal operation. The assigned material properties are also based on available results obtained from in situ and laboratory tests and on the results of visual inspection and historical research carried out for both old bridges.     

A technological study of ancient faience from Egypt

The chemical compositions and microstructures of some 35 faience objects from Egypt spanning the period from the Middle Kingdom through to the 22nd dynasty are determined using analytical scanning electron microscopy. Replicate faience beads glazed in the laboratory using the efflorescence and cementation methods are similarly investigated. In efflorescence glazing, there appears to be preferential efflorescence of soda over potash, and in cementation glazing, preferential take up of potash over soda into the glaze. These data are then used to try to infer the raw materials and methods of glazing employed in the production of the ancient faience. The glaze/glass phases present in the faience differ significantly in composition from that of New Kingdom glass. This could be due either to the use of different plant ashes or to changes in the composition of the plant ashes during the production of faience and/or glass. Although it is only rarely possible to determine with certainty whether ancient faience was glazed by efflorescence, cementation or application, the observed microstructures provide an indication of the approach adopted to achieve desired performance characteristics such as strength.     

"天高皇帝近":一个重要的中国思想史命题——雷戈《秦汉之际的政治思想与皇权主义》评介

雷戈所著《秦汉之际的政治思想与皇权主义》一书,认为从秦朝到汉初的思想史发展阶段是中国思想史上皇权主义意识形态的生成和确立时期,并将其概括为"后战国时代";采用独特的"历史-思想"研究法,从政治制度、官场规则和官吏的政治生活中,挖掘特定时期的政治思想共识,为政治思想史研究开辟了新的路径,并扩大了思想史的资料范围;认为秦汉时期生成的皇权主义秩序,把"天高皇帝远"的制度现实变为"天高皇帝近"的观念实存,实现了对人们思想的可控性,从此,思想成为皇权可以控制和规范的领域,达到了有效的思想专制。这是秦汉以降中国思想史发展的基本特征。该书在研究方法的创新和思想深度的开掘上,都做出了独到的贡献。     

让材料自己说话——浅论当前历史传记写作的一种趋势

《陈寅恪的最后二十年》、《顾颉刚和他的弟子们》、《束星北档案》等著作,代表了当前历史传记写作的一种趋势。《陈寅恪的最后二十年》的文本近似历史叙事散文;《顾颉刚和他的弟子们》的文本更接近史学论文;而《束星北档案》则类同电视记录片的文稿。这些著作共有的特点是:在修撰方式上,大量运用了第一手材料;在文本风格上,力求作品深入浅出、雅俗共赏;在写作理念上,坚持真实第一,尊重历史。这一趋势非常值得重视。     

劳动力市场竞争与分割的再认识

马克思在《资本论》中所论述的劳动力买卖、平均利润与生产价格,都是以完全竞争或自由竞争为前提条件的。但是,马克思指出,这是一种"理论上的假定"。这就存在着如何把马克思抽象化的理论运用于活生生的现实的问题。在现实生活中,劳动力市场既有竞争的一面,又有分割的一面,而且二者往往是交错在一起的。     

论产业集群在提升城市竞争力中的综合功效

本文通过对产业集群在提升城市竞争力中的功效分析,指出政府在培育和发展产业集群中应发挥重要作用。     

Doing Archaeology as a Feminist: Introduction

Gender research archaeology has made significant contributions, but its dissociation from the resources of feminist scholarship and feminist activism is a significantly limiting factor in its development. The essays that make up this special issue illustrate what is to be gained by making systematic use of these resources. Their distinctively feminist contributions are characterized in terms of the recommendations for “doing science as a feminist” that have taken shape in the context of the long running “feminist method debate” in the social sciences.     

城市发展指数指引下的我国收缩区域初步评判

城市收缩在全球范围内蔓延，致使以增长为假设前提的区域经济增长模型受到极大挑战。本文以县域单元为研究对象，利用2000年与2010年各县域单元的社会经济数据构建城市发展指数，在其指引下对我国城市收缩状况做初步分析。研究表明：①在城市化的快速进程中，我国县域单元出现收缩现象，特别是县、自治县、自治旗、旗出现较多数量的收缩。②发生收缩的县域单元共261个，大多数为人口较少的中小城镇；西部地区分布较多，且收缩面积较大。③收缩的县级行政区表现出一些共性特征：人口数量和密度下降、老龄化加深、医疗卫生条件较差、经济发展缓慢，财政赤字严重。这一结果有助于初步了解我国收缩区域整体格局，并呼吁研究者和政策制定者尽快针对这一问题展开研究，促进区域可持续发展。     

大数据背景下国内人文地理研究进展与方法审视

通过梳理人文地理领域杂志近年大数据文章解释其与大数据应用的关系，强调其应用给人文地理学研究带来机遇和挑战：①大数据作为研究方法，不能代替传统人文地理研究范式，而是对现研究方法的补充。大数据和小数据需对话交流；②大数据本身是一种话语权，嵌入人文地理研究系统。保证人文地理学多样性，避免过度依赖大数据，需在批判角度审视和运用；③需关注大数据对于人文地理学研究方法和思想的影响；④运用大数据解读地理和空间过程复杂性的同时，应看到大数据应用对公共服务的潜力，思考其结果如何更好的服务社会。     

从“社”到“庄”:清代前期山东寿光县顺庄法的推行

清康熙年间,山东寿光县为缓解"大差"负担,将"大差"由轮当制改为下放给各社自理,但这进一步加重了民间劈社的窘境。乾隆年间知县王椿在缺少土地记录的情况下,采用"顺庄法"重整地方组织,缓解赋税征收的困境。以百姓实际居住的"庄",取代官方登记的里甲组织"社",作为税收登记与征收的基本单位。同时,这也形成了山东以"村庄"为基层组织的地方社会。因南北土地分布状况的差异,顺庄法在山东与江南显示出不同的形态与结果。