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71.
This study is aimed at investigating the demand on shear panel dampers (SPDs) installed in steel structures under strong earthquake motions to serve as guidance for the recommended capacity of SPDs in seismic design. For this purpose, an extensive dynamic analysis is carried out on steel bridge pier structures with SPD devices. To describe the restoring force characteristics of SPDs, the analysis uses a newly developed combined hardening model based on experimental data. The seismic demands made on SPD devices are examined and then summarized to give recommended values for determining the necessary deformation capacity of SPDs. 相似文献
72.
Lin Chen 《Journal of Earthquake Engineering》2013,17(4):505-534
This article concerns the cross-interaction problem among multi-foundations on a linearly viscoelastic medium at very small shear strains. In the analysis, the foundations are discretized into a number of sub square-elements. The dynamic response within each sub-element is described by the Green’s function, which is obtained by the Fourier-Bessel transform and the precise integration method. Incorporating the displacement boundary condition and the force equilibrium of the foundations, it obtains the dynamic impedance and compliance functions of the foundations. Extensive results for two rigid circular foundations placed at different separations are presented. Parametric studies are carried out on the dynamic interaction among adjacent foundations. Illustrative results for several closely spaced foundations are also illustrated. 相似文献
73.
ABSTRACT Rapid population growth and increasing water development costs have prompted many western governments to condition residential development approval on the adequacy of water supplies. We examine the effects of these regulations on housing supply in Colorado and New Mexico using fixed‐effects panel regressions. Our findings suggest that price‐based tools to ensure water availability may be a preferred regulatory alternative to quantity restrictions. Attempts to restrict groundwater basin access have not unambiguously corrected negative externalities related to growth. Meanwhile, Colorado cities' aggressive use of impact fees has facilitated water resource development, without limiting growth. 相似文献
74.
Chen Xiu-Qin Arthur J. Boucot 《Alcheringa: An Australasian Journal of Paleontology》2013,37(2):403-412
Leptocoeliid brachiopods from the Early Devonian Baruntehua Formation of Dong Ujimqin Qi, northeastern Inner Mongolia were assigned to Leptocoelia by Su (1976) and Zhang(1983), and subsequently to Pacificocoelia by Hou & Boucot (1990). Transverse serial sections of Pacificocoelia sinica are illustrated hère, for the first time, based on topotype specimens. The known geographic range o Pacificocoelia is from northern China, North America, South America and Kazakhstan (Eastern Americas Realm and also occurs in east-central Asia). Atlanticocoelia is regarded hère as a junior synonym of Pacificocoelia. 相似文献
75.
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77.
Dongya Y. Yang Li Liu Xingcan Chen Camilla F. Speller 《Journal of archaeological science》2008,35(10):2778-2785
Recent zooarchaeological studies on water buffalo (Bubalus sp.) remains from China and south Asia question the traditional view that water buffalo were first domesticated in Neolithic China over 7000 years ago. The results from several recent population genetic studies of modern domesticated buffalo (Bubalus bubalis) are not consistent with each other, placing the original center of buffalo's domestication in south Asia, southeast Asia, or China. This paper reports a study using an ancient DNA approach to analyze water buffalo remains from Neolithic sites in north China to investigate their affinities with modern domesticated water buffalo, and to shed light on the origin of modern domesticated water buffalo in China.A 169 bp fragment of D-loop mitochondrial DNA was successfully amplified and verified for 13 of 24 bone samples obtained from seven archaeological sites along the Wei River valley in Shaanxi Province, China. The bone samples which yielded positive DNA can be dated to 8000–3600 cal. BP. The phylogenetic analysis of the obtained DNA sequences along with modern water buffalo sequences indicated that the ancient water buffalos were not the direct ancestor of modern domesticated water buffalo. However, the phylogenetic analysis, along with BLAST searches of these ancient DNA sequences, did demonstrate their relatedness to water buffalo more so than to any other bovid species, confirming the existence of indigenous wild (but now extinct) water buffalo species (B. mephistopheles) in ancient China.The DNA analysis of these ancient remains failed to establish direct links between modern domesticated water buffalo (B. bubalis) and indigenous water buffalo (B. mephistopheles) from ancient China. If further DNA studies of more ancient remains from other regions of China confirm the observation of solely indigenous water buffalo species in ancient China, it would suggest modern water buffalo might not have been first domesticated in China. 相似文献
78.
Xiaolong Luo Jianfa Shen Wen Chen 《Geografiska annaler. Series B, Human geography》2010,92(4):311-326
During the transition towards a more market‐oriented economy and entrepreneurial governance, local authorities have attempted to create new cross‐jurisdiction regional entities to enhance their competitiveness through making city‐region plans or regional strategic plans in China. This article analyses the process of region building in China through a case study of Nanjing city‐region. We argue that region building is a state‐led regional project in China, not a spontaneous process. City‐region planning has played a legitimacy‐seeking role in the construction of new regions. Based on the discourse provided by the city‐region plan, associated city networks are being created as a mechanism for plan implementation and regional coordination. This signals that regional planning is entering the stage of regional institution building. By assessing the capacity of regional institutions, we argue that the newly‐emerged regional institutions or urban networks have facilitated regionalization in terms of the increasing involvement of non‐state actors, the formation of regional coherence and identity and the enhanced inter‐city co‐operation. However, it is still difficult to establish effective regional governance due to competing local governments, the arbitrary political leadership and the fragmented planning functions. 相似文献
79.
Recent developments in the biopharmaceutical industry in Taiwan, South Korea and China bear witness to the transformation of these states in nurturing an innovation‐based industry. This article argues that the segmentation of the value chain of the biopharmaceutical industry has provided industrializing countries with a window of opportunity. These East Asian states have modified their former catching‐up approaches by establishing a more effective institutional platform that can attract knowledge‐creation players to the industry. Through case studies, the authors show that the Taiwan state's promotion of the biopharmaceutical industry has been based on an incremental approach; existing state policies have been modified to cope with the demands of the industry, which has resulted in the continuation of its SME‐based industrial structure. The methods of the Korean state have been more radical, in that the policies that previously favoured the chaebols have gradually been reoriented toward the promotion of smaller, science‐based firms that now co‐exist alongside the chaebols. Finally, the Chinese state and local governments have sought to promote this innovation‐based industry by building biotech parks. This approach has resulted in a boom in new science firms, which have become increasingly isolated from the flourishing domestic SOE‐led market. 相似文献
80.
Ken Frank I‐Chien Chen Youngmi Lee Scott Kalafatis Tingqiao Chen Yun‐Jia Lo Maria Carmen Lemos 《政策研究杂志》2012,40(3):492-515
This study explores how a scientist's location in science‐based policy networks can affect her policy‐oriented behaviors. In particular, we hypothesize that those scientists who fill structural holes in their networks will be more likely than others to engage in policy‐oriented behaviors. The network data are defined by scientists' coauthorship on policy documents regarding climate change in the Great Lakes. We employ a two‐mode network analysis to identify clusters of scientists who coauthored similar documents, and relative to those clusters, we identify those who fill structural holes by bridging between clusters. We find that those scientists who bridged between clusters were more likely to engage in policy‐oriented behaviors of policy advocacy and advising than were others in the network. This is an example of a link between network location and policy‐oriented behavior indicative of the broader phenomenon of how individuals exert agency, given structural constraints. 相似文献