室内管道系统抗震研究综述   总被引：1，自引：0，他引：1  

刘志斌  郭恩栋  李倩  李玉芹 《震灾防御技术》2019,14(3):591-599

根据最新震害统计资料发现，非结构构件在地震中造成的经济损失远大于结构构件。非结构构件按照地震反应特征可分为位移敏感型构件和加速度敏感型构件。其中，位移敏感型构件的破坏多受层间位移角控制，主要采用拟静力试验进行研究；加速度敏感型构件的破坏多受楼面加速度的控制，主要采用振动台试验进行研究。室内管道系统是非结构构件的重要组成部分，室内管道系统中的立管和水平管分别属于位移敏感型和加速度敏感型构件。本文系统地论述了近年来国内外学者开展的关于室内管道系统的抗震研究工作，并对室内管道系统下一步的研究工作提出了建议。  相似文献   

The British Palaeogene Volcanic Province - Ailsa Craig Geological Conservation Review site     

C.G. Smith  R.M.L. Wignall 《Proceedings of the Geologists' Association. Geologists' Association》2021,132(1):16-23

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云降水物理和人工影响天气研究进展和思考   总被引：4，自引：0，他引：4  

洪延超  雷恒池 《气候与环境研究》2012,17(6):951-967

云降水物理和人工影响天气密不可分,云降水物理为人工影响天气提供理论基础,人工影响天气是云降水物理一个重要应用领域.目前我国人工影响天气规模、经费投入已达世界之最,人工影响天气工程正在建设之中.论文简要回顾了我国云物理研究和人工影响天气的发展过程,评述研究工作取得的进展,思考我国人工影响天气在新形势下进一步的发展的问题,显得尤为重要.几十年来,我国开展了一系列云雾降水的外场观测研究和人工影响天气的外场试验研究,云和降水物理以及人工影响天气的理论和技术研究不断取得进展,数值云模式和中尺度模式的模拟研究水平有了长足的进步,在云和降水物理过程和降水机制研究、云的微物理结构、云水资源和人工增雨潜力评估、催化条件预测、催化剂和催化技术等方面取得了显著进展.论文最后指出,目前的人工影响天气需要加强人工影响天气核心技术研究,并提出了需要进一步研究的云和降水物理中的有关科学问题.  相似文献   

A review of EU bio-economic models for fisheries: The value of a diversity of models     

Raúl Prellezo  Paolo AccadiaJesper L. Andersen  Bo S. AndersenErik Buisman  Alyson LittleJ. Rasmus Nielsen  Jan Jaap PoosJeff Powell  Christine Röckmann 《Marine Policy》2012,36(2):423-431

The lessons learned from a review of thirteen existing European bio-economic models used in the evaluation of EU policies are presented. How these models compare and differ in terms of their biological and economic components, the integration between the components, which indicators are selected and how they are used, are described and analysed. The article concludes that the multitude of construction differences reflects the necessity of adapting the modelling approach to answer different questions. Since real life questions in fisheries are so diverse, answering them requires a diversity of models.  相似文献   

硼氢化钠的电化学制备研究进展   总被引：1，自引：1，他引：0       下载免费PDF全文

周永全  房艳  房春晖 《盐湖研究》2012,20(4):57-62,72

对国内外电化学硼氢化的研究进行了综述。以电化学还原偏硼酸钠制备硼氢化钠为主线探讨了电极材料、电解液组成、电解槽和隔膜及添加剂等因素对电化学硼氢化的影响。论述了研究电化学还原偏硼酸钠的机理和重现性,并对其更进一步研究进行了展望。  相似文献   

海洋社会学:回顾、比较与前瞻     

刘勤 《广东海洋大学学报》2013,(2)

学术之势、国家之势与民众之势推动了海洋社会学的拓荒开路,迄今已形成数个有一定影响力的研究团队。其研究成果,在核心概念的厘清中形成了从形式主义向实体主义的演进,在体系架构的理念上呈现了从移植设计到认知的创新,在范式立场的坚守中表达了中国立场和中国视角的本土贡献,从而为深化和拓展海洋社会学的研究提供了方向。  相似文献   

降雪与冻雨天气研究回顾   总被引：7，自引：5，他引：2  

刘熙明  许爱华 《气象与减灾研究》2008,31(4):59-64

2008年初，中国南方许多地区出现了历史罕见的持续雨雪、冰冻天气，对电力、交通、农业、林业等造成了极大破坏。分析研究这种在全球气候变化背景下发生的极端天气事件的形成原因，有助于提高预测水平和对类似灾害性天气的防范能力。在对近年来国内外关于冬季降雪和冻雨天气研究进行简略回顾的基础上，对其未来研究方向进行了展望。认为：在全球气候变暖的背景下，要加强雨雪、冰冻天气形成机理与变化规律的研究，特别是要加强其发生的前兆性研究；要充分利用现代先进的探测技术和手段，提高对雨雪、冰冻天气的监测能力；要建立和完善对雨雪、冰冻灾害天气时间发生、发展的预报技术和方法。  相似文献   

An overview of physical and ecological processes in the Rio de la Plata Estuary     

E. Marcelo Acha  Hermes Mianzan  Raúl Guerrero  José Carreto  Diego Giberto  Norma Montoya  Mario Carignan 《Continental Shelf Research》2008

The Rio de la Plata is a large-scale estuary located at 35°S on the Atlantic coast of South America. This system is one of the most important estuarine environments in the continent, being a highly productive area that sustains valuable artisanal and coastal fisheries in Uruguay and Argentina. The main goals of this paper are to summarize recent knowledge on this estuary, integrating physical, chemical and biological studies, and to explore the sources and ecological meaning of estuarine variability associated to the stratification/mixing alternateness in the estuary. We summarized unpublished data and information from several bibliographic sources. From study cases representing different stratification conditions, we draw a holistic view of physical patterns and ecological processes of the stratification/mixing alternateness. This estuary is characterized by strong vertical salinity stratification most of the time (the salt-wedge condition). The head of the estuary is characterized by a well-developed turbidity front. High turbidity constrains their photosynthesis. Immediately offshore the turbidity front, water becomes less turbid and phytoplankton peaks. As a consequence, trophic web in the estuary could be based on two sources of organic matter: phytoplankton and plant detritus. Dense plankton aggregations occur below the halocline and at the tip of the salt wedge. The mysid Neomysis americana, a key prey for juvenile fishes, occurs all along the turbidity front. A similar spatial pattern is shown by one of the most abundant benthic species, the clam Mactra isabelleana. These species could be taken advantage of the particulate organic matter and/or phytoplankton concentrated near the front. Nekton is represented by a rich fish community, with several fishes breeding inside the estuary. The most important species in terms of biomass is Micropogonias furnieri, the main target for the coastal fisheries of Argentina and Uruguay. Two processes have been identified as producing partially stratified conditions: persistent moderate winds (synoptic scale), or low freshwater runoff (interannual scale). Less frequently, total mixing of the salt wedge occurs after several hours of strong winds. The co-dominance of diatoms (which proliferate in highly turbulent environments) and red tides dinoflagellates and other bloom taxa (better adapted to stratified conditions), would indicate great variability in the turbulence strength, probably manifested as pulses. Microplankton and ichthyoplankton assemblages defined for the stratified condition are still recognized during the partially mixed condition, but in this case they occupy the entire water column: vertical structure of the plankton featuring the stratified condition become lost. Bottom fish assemblages, on the contrary, shows persistence under the different stratification conditions, though the dominant species of the groups show some variations. Summarizing, the Río de la Plata Estuary is a highly variable environment, strongly stratified most of the time but that can be mixed in some few hours by strong wind events that occur in an unpredictable manner, generating stratification/partially mixed (less frequently totally mixed) pulses all along the year. At larger temporal scales, the system is under the effects of river discharge variations associated to the ENSO cycle, but their ecological consequences are not fully studied.  相似文献   

中国石油生产的展顾     

周全浩 《云南地理环境研究》1990,2(1):1-9

本文分析了中国石油生产近20年变化的原因,对一些学者认为80年代中国会成为超级产油大国,后又悲观断定80年代中国可能变成石油净进口国作了评述。同时对90年代中国石油生产前景作了初步展望。  相似文献   

西方国家办公空间研究综述   总被引：2，自引：0，他引：2  

温锋华  XU Xue-qiang  李立勋 《世界地理研究》2008,17(2):85-94

文章分别从区位论、城市空间结构理论等角度入手,总结了西方早期上述理论体系中办公空间研究的相关内容,并从办公空间的区位特征、集聚与扩散及其空间结构形成机制等方面对西方战后在办公空间方面的研究进展进行了综述,还对西方办公空间的研究方法进行了总结,最后结合我国的实际情况对西方的研究进行了述评,以期为我国相同领域研究的开展提供一点启示。  相似文献