基于企业网络视角的城市网络研究进展与展望

随着生产分割程度的不断加深,企业网络空间增长已经成为城市网络生长发育的重要驱动力量。近30年来,基于企业网络视角的城市网络研究日益增多,在链接关系及时空过程、价值生产空间格局、外部经济及其空间差异、规划实践及治理模式四个方面取得了重要进展。本文在梳理城市网络发展脉络的基础上,从多维视角提出了基于企业网络视角的城市网络理论体系研究框架。总体来看,基于企业网络视角的城市网络研究还处于起步发展阶段。围绕完善理论体系建设,未来研究应着力在5个方面取得进展：城市网络分析技术方法的发展完善、城市网络多维度时空过程的综合比较研究、城市网络发育过程的微观机理解析、城市网络演化模式理论模型研制、城市网络的治理模式和政策框架研究。     

Potential Use of Foamed Mortar (FM) for Thermal Upgrading of Chinese Traditional Hui-Style Residences

The Hui-style residence is an important architectural heritage of China. The hollow wall structures are widely used to build its exterior wall system. However, the thermal performance of the hollow wall is no longer able to meet the new energy-saving and environmental requirement. This article describes a laboratory study of the development of foamed mortar (FM), with the potential for use in thermal upgrading of the Hui-style hollow wall system without dramatically changing its traditional structure. The key early age, physical, mechanical and thermal properties were systematically measured. Two extended models were respectively developed to calculate compressive strength and thermal conductivity, as a function of porosity. Environment chamber test was also employed to investigate the effectiveness of this novel thermal upgrading approach and the results show that filling the voids with FM can effectively improve the overall thermal resistance of the hollow wall system by 44%, which is almost equal to the overall thermal resistance when using the more expensive commercial inorganic stucco system. In addition, the combination of these two methods yielded an overall thermal resistance of 0.701 m²·K/W, which is even higher than 0.67 m²·K/W for the code required in the hot summer/cold winter climate zone.     

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.     

Context and the role of policies to attract foreign R&D in Europe

This paper explores the effectiveness of policies ‘in’ attracting the foreign research and development (R&D) of multinational enterprises (MNEs) to specific countries in Europe. We develop a macroeconomic investigation covering 29 European countries during the period between 1990 and 2012 in order to address: (a) whether the provision of direct financial support for business R&D is effective for the attraction of foreign R&D; (b) whether direct support is more effective than indirect support for this purpose and (c) whether the link between direct financial support for business R&D and the foreign R&D of MNEs is conditioned by the context within which the support is provided. The results of the analysis show that, first, the provision of direct financial support is generally effective for the attraction of foreign R&D by MNEs. Second, direct support for business R&D is more effective for this purpose than indirect support. Third, the provision of direct financial support for business R&D yields greater returns in contexts that are more socio-economically suitable for knowledge-intensive, innovative activity.     

Assessing the Scale and Pace of Large Shell-Bearing Site Occupation in the Prince Rupert Harbour Area,British Columbia

Methodological advancements in geoarchaeology and spatial and chronological modeling are opening new avenues to interpreting large coastal shell-bearing sites. We document the developmental histories of two such sites around Prince Rupert Harbour, Canada, using systematic percussion coring, intensive radiocarbon dating, and 3D surface mapping with Total Station and LiDAR. We also re-analyze a third site (Boardwalk/GbTo-31) excavated and radiocarbon dated in the 1960s, 1970s, and early 2000s using archival field notes, site maps, and stratigraphic profiles georectified using LiDAR. We map the natural landform beneath the sites and document the degree to which people physically modified landforms through the deposition of massive shell accumulations. We model site development through time and space and use accumulation rates and OxCal modeling to test for intentional deposition events. All three sites demonstrate complex and heterogeneous occupation histories. At each we identify instances of very rapid deposition that effectively terraced and extended parts of the natural landform to create places for constructing houses, though these episodes take place within longer histories of slower quotidian deposition. The anthropogenic modifications to the coastline in this area are the result of these mixed processes associated with long histories of occupation.     

Crowdsourcing Model Research for the Identification of Post-Earthquake Rescue Objects

The quick and accurate identification of post-earthquake rescue objects can minimize the casualties and property loss caused by earthquakes. With the rapid development of remote sensing technology, rescue objects can be identified through high-resolution remote sensing images. There are two main categories of approaches to identify rescue object through high-resolution images: automatic extraction by a computer and visual judgment by professionals. Although results can be obtained quickly by using automatic extraction, the accuracy of the results is unacceptably low. For visual judgment, the large demands for time and professionals restrict its wide practical application. In this study, we introduce crowdsourcing into the identification of post-earthquake rescue objects. First, we integrate the advantages of the computer and crowdsourcing, which means that the computer takes advantage of the speed of information processing, while crowdsourcing makes full use of human recognition capabilities. Second, we take visual judgment tasks out of the hands of professionals and entrust the tasks to workers in a crowdsourcing platform. Not only are the human resources infinite, but we can also improve the efficiency of identifying rescue objects. Third, we propose a crowdsourcing model that improves the quality of the results and saves human resources. Finally, experimental results demonstrate that our solution is feasible.     

多种科技方法在古月桥勘察修缮设计中的应用

建于南宋嘉定六年(公元1213年),位于浙江省义乌市的古月桥是折边拱桥这种桥梁发展过渡形式中不可多见的典型实证,具有极高的历史、科学、艺术、文化和社会价值。为了明确古月桥目前的状态,分析其主要威胁及病害原因,判断结构稳定性,进而制定有针对性的修缮方案,采用多种科技方法对古月桥进行了勘察和综合判断。面对桥身残破的现状,工作组采取了三维激光扫描、微观实验、结构分析等多种科技方法综合勘察,不仅较为清晰的地了解了古月桥的病害威胁,也分析了其背后致因及相互之间的联系;最终对古月桥稳定性及保存状况做出了综合判断。上述多种方法的应用,不仅相互印证了勘察结论,也为后续保护工作提供了重要的依据。     

Welshness in ‘British Wales’: negotiating national identity at the margins

Popular interpretations of national identity often focus on the unifying qualities of nationhood. However, societies frequently draw hierarchical distinctions between the people and places who are ‘most national’, and those who are ‘least national’. Little attention is paid to these marginal places within the nation and the experiences of their inhabitants. This article helps to address this by analysing the ‘less Welsh’ British Wales region of Wales, a country that has traditionally possessed a hierarchical, regionally constituted nationhood. The article studies the British Wales region both ‘from above’ – considering how some areas develop as ‘less national’ – and ‘from below’, introducing empirical ethnographic work into ‘everyday Welshness’ in this area. Whilst previous work on hierarchical nationhood focuses on how hierarchies are institutionalized by the state, this article demonstrates how people at the margins of the nation actively negotiate their place in the nation. Whilst people in this area expressed a strong Welshness, they also struggled to place themselves in the nation because they had internalized their lowly place within the national hierarchy. The article demonstrates the importance of place and social class for national identity construction and draws attention to the role of power in the discursive construction of hierarchical nationhood.     

Studying Immigrant Policy One Law at a Time

This article shows that, in the study of immigrant integration policy in the U.S. states, it is critical to report data and coding decisions for individual laws. This analysis uses an updated and public database of law‐level decisions, which includes 2,703 legislative actions recorded by the National Conference of State Legislatures from 2005 to 2016. These data are used to estimate models of aggregate state policy activity in a variety of ways: as a single continuum of policy balance versus separate models of welcoming and hostile, lumping all policy subareas together versus analyzing a specific subarea, and lumping all years together in one cross section versus panel analysis. The results in these models differ enough to indicate that reporting codes for individual‐level laws is absolutely essential so that each researcher easily can construct the measure that fits his or her theoretical framework best.     

Studying the process of enamel powder preparation for émail champlevé by colour measurements and μ‐X‐ray mappings

Colour measurements and non‐destructive μ‐X‐ray mappings have been used for the first time in a comprehensive study of medieval émail champlevé works from different production areas in France and Germany. This approach has given a new insight into the enamel powder preparation process of the glass material used for enamelling. Colour measurements demonstrated that all production centres used glass of very similar hues, but with large differences in colour saturation. The μ‐X‐ray mapping results of blue enamels are described by a semi‐qualitative approach. Significant variations in oxide contents of lead, cobalt, manganese and antimony oxides were found. The variations suggest that more than one glass material was used to prepare the powder for enamelling. The variations in antimony and cobalt show that glass had different degrees of opacity and colour depth. The manganese and lead contents, which do not correlate with the cobalt or antimony contents, indicate that probably glass of different base compositions was used to prepare the enamel powder for one champlevé field.