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511.
A three-dimensional regional Eulerian model of sulfur deposition and transport is developed. Processes treated in the model include emission, transport, diffusion, gas-phase and aqueous-phase chemical process, dry deposition, rainout and washout or sulfur. A “looking up table” method is provided to deal with the gas-phase chemical process including sulfur transfer. Dry-depositon velocity considers the influence of underlying surface, wind, degree of stabil-ity by parameterization. Model calculated values reasonably agrees with observation. Distribution of sulfur deposi-tion and transport in East Asia are also analyzed in this paper. Some amount of sulfur emission of different countries transport across boundaries, but the main origin of sulfur deposition in each country in East Asia is from itself. Furthermore, some transport paths on different layers and outlet or inlet zones are found. According to sulfur bal?ance and budget we concluded that sulfur outlets are bigger than inlets across boundary and emissions are more than deposition in most places of East Asia. 相似文献
512.
地理系统工程在战区军事地理电子地图集设计中的应用 总被引:1,自引:0,他引:1
在论述地理系统工程和电子地图集设计的关系的基础上,探讨了战区军事地理电子地图集的性质、用途和构成体系。 相似文献
513.
Nicky Gregson 《Geoforum》2003,34(1):5-7
In this response to Nigel Thrift’s ‘The future of geography’, I highlight the performative qualities of academic response. As a counter to Thrift’s optimism, I argue that such debate is inevitably parochial and imperialist. I question the validity of such ‘discipline games’ in a post-disciplinary world, emphasise the importance of a performative reading of academic futures and highlight that geographical journal space remains worryingly within-discipline, rather than post-disciplinary. More generally, I suggest that there are clear material risks to continuing to play discipline games in a post-disciplinary world. 相似文献
514.
暴雨与非暴雨过程涡散场能量收支特征 总被引:7,自引:7,他引:7
选取云南暴雨和非暴雨两类天气过程,分别应用人选上支方程计算了暴雨区面积-时间平均参量收以各项量值,给出了对流层整层和上(200-400hPa)中(400-600hPa)下(600-800hPa)各层涡散场动能源汇特征,同时还指出了两类天气在动能制造、能量转换等方面存在的较差异,尤其是两类天气的大多数能量收支磺符号相反 相似文献
515.
《方志月刊》是中国近代唯一的一种侧重于区域地理的刊物,刊物的名称选择、编辑特色等均受到了主编张其昀地理学思想的影响.通过对《方志月刊》载文及相关史实的梳理与考证,解析其办刊特色和地理学贡献.研究表明:该期刊注重科学的区域地理研究和地图、照片的运用,注重国外地理学成果的介绍和地理学史的整理,为中国近代地理学特别是区域地理... 相似文献
516.
Through the Upper Jurassic and Lower Cretaceous gravity-flow sandstones were deposited in the Danish Central Graben. These gravity-flow sandstones were deposited within mudstones of the Farsund Formation which is the main source rock in the area, and they are thus potential oil and gas reservoirs. The petrography and geochemistry of the sandstones show good intra well relations and several local geographical relations, which may indicate that they were derived from multiple locally sourced flows and not merely by one basin-axial flow system. The gravity-flow sandstones deposited in the eastern part of the basin are less mature and richer in, especially, carbonates and albite compared to previously deposited Jurassic sandstones and simultaneously deposited sandstones in the western part of the Danish area. This may indicate a division of the basin in an eastern and a western provenance province. This study addresses the provenance of the gravity-flow sandstones by petrographical and geochemical analyses in order to derive possible shared detrital sources as a means of understanding the transport system(s) of the gravity flows. 相似文献
517.
A three-dimensional finite difference transport model appropriate for the coastal environment is developed for the solution of the three-dimensional convection-diffusion equation. A higher order upwind scheme is used for the convective terms of the convection-diffusion equation, to minimise the numerical diffusion. The validity of the numerical model is verified through five test problems, whose exact solutions are known. 相似文献
518.
This study assesses the effects of a high rise building on the beach and dune at an intensively developed shoreline through field investigation of geomorphological and sedimentological characteristics and wind tunnel investigation of wind speed and direction. Results indicate that wind speed is increased close to the building, where wind is often deflected to a more onshore direction. Obliquely offshore northwesterly winds are the most dramatically altered and cause onshore flows (with pronounced upward flows) in the landward portion of the beach near the building. Onshore deflections in wind direction cause besanding of the boardwalk and create highly localized scour and deposition zones. A dune on the backbeach breaks up zones of sediment transport and scour and diminishes the likelihood that scour areas will cause increased hazard to landward buildings as a result of flooding. Generic large-scale studies are required to develop criteria for communities to use to specify optimum dimensions, locations and shapes of landforms that are modified or created by high rise structures. 相似文献
519.
区域开发整治中的政策研究主要包括对现行政策进行效果评价和影响分析,并预测其对区域开发整治可能产生的积极和消极作用,从而为现行政策修正以及新政策的制定提供依据,供决策机构参考。区域开发整治政策具有地方性、阶段性和稳定性特征。地理学在区域开发整治中重点研究的应是自然、经济和社会相互联结的综台性政策问题,主要有资源利用政策、环境保护政策、生产布局政策以及城市发展政策等等。 相似文献
520.
Keith Paterson 《地球表面变化过程与地形》1987,12(5):575-581
This paper reviews the educational merits and application of limestone landform studies in British secondary schools and considers these in the context of recent developments within geomorphology and the geography curriculum. The relevance of both traditional and newer approaches to the field study of karstforms is highlighted together with developments in classroom activities. School-based work is shown to have benefitted considerably from advances in educational technology. 相似文献