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51.
麻阳九曲湾砂岩铜矿床地质特征及富集规律与找矿方向 总被引:2,自引:0,他引:2
本文介绍了九曲湾铜矿床的地质特征,初步揭示了沅麻盆地白垩纪砂岩铜矿化富集规律及找矿方向。 相似文献
52.
R. N. Colvile R. Sander T. W. Choularton K. N. Bower D. W. F. Inglis W. Wobrock D. Schell I. B. Svenningsson A. Wiedensohler H. -C. Hansson A. Hallberg J. A. Ogren K. J. Noone M. C. Facchini S. Fuzzi G. Orsi B. G. Arends W. Winiwarter T. Schneider A. Berner 《Journal of Atmospheric Chemistry》1994,19(1-2):189-229
The airflow, cloud microphysics and gas- and aqueous-phase chemistry on Kleiner Feldberg have been modelled for the case study of the evening of 1 November 1990, in order to calculate parameters that are not easily measured in the cloud and thus to aid the interpretation of the GCE experimental data-set. An airflow model has been used to produce the updraught over complex terrain for the cloud model, with some care required to ensure realistic modelling of the strong stable stratification of the atmosphere. An extensive set of measurements has been made self-consistent and used to calculate gas and aerosol input parameters for the model. A typical run of the cloud model has calculated a peak supersaturation of 0.55% which occurs about 20 s after entering cloud where the updraught is 0.6 m s–1. This figure has been used to calculate the efficiency with which aerosol particles were scavenged; it is higher than that calculated by other methods, and produces a cloud with slightly too many droplets. A broad cloud droplet size spectrum has been produced by varying the model inputs to simulate turbulent mixing and fluctuations in cloud parameters in space and time, and the ability of mixing processes near cloud-base to produce a lower peak supersaturation is discussed. The scavenging of soluble gases by cloud droplets has been observed and departures from Henry's Law in bulk cloud-water samples seen to be caused by variation of pH across the droplet spectrum and the inability of diffusion to adjust initial distributions of highly soluble substances across the spectrum in the time available. Aqueous-phase chemistry has been found to play a minor role in the cloud as modelled, but circumstances in which these processes would be more important are identified. 相似文献
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The exponential downstream decline in particle size predicted by Sternberg (1875) is examined within a highly active alpine fluvial environment, the gravel-bed Squamish River in southwestern British Columbia. Transect survey procedures for sampling within the coarse alluvial gravels are described in detail. Downstream trends for various particle size statistics, plotted with distance from a major sediment source, are considered according to two scenarios. Evaluation of overall trends indicates that the downstream expression derived by Sternberg (1875) is not the most appropriate; rather, curves are better described by power functions. This reflects a very rapid decline in particle size immediately downstream of the major sediment source. Secondly, evaluation of downstream trends in relation to channel planform determines that exponential functions with different coefficients describe adequately relations within individual planform reaches. There is insufficient evidence to suggest which of these two scenarios may be appropriate. Several lines of evidence suggest that the trends found are more the result of selective sediment transport phenomena than of abrasion, a condition attributed to channel competence within a system dominated by sediment-supply conditions. 相似文献
55.
Partition, not kinetics, ultimately determines the concentration of highly soluble gases in cloud droplets. Partition equations are formulated and applied to idealized air-mass thunderclouds and precipitating stratus. Contribution to aqueous concentrations from sub-cloud scavenging of highly soluble gases is estimated at between 10 and 20% under relatively unpolluted conditions. Data indicate that evaporation can produce enhancements in concentration of as much as a factor of 3. The calculations give large-scale mean coefficients of wet removal of highly soluble gases of about 2.8×10-6 s-1 (4-day residence time) for air-mass thunderclouds and precipitating stratus. Removal is so effective that the mean scale heights of these gases should be decreased to 2 km or less. The criterion of high solubility in this paper is that K
H (Henry's Law coefficient) > 105 mol l-1 atm-1. Gases that are effectively highly soluble include HCl, HNO3, H2SO4, H2O2, NH3 in acid droplets, SO2 in oxidizing droplets (and probably some light amines and sulfonic acids), but not SO2 in the absence of oxidants, nor HCHO. A variation of removal coefficient and scale height with solubility is presented. A comparison of atmospheric NH3 concentrations deduced from rain NH4
+ and measured directly gives reasonable agreement. 相似文献
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2013年我国首次向全世界提出人类命运共同体理念,在全球范围内积极倡导人类命运共同体的构建。东北亚共同体是人类命运共同体的组成部分,是中国打造周边命运共同体的重要助力,同时为辽宁海洋经济的发展带来了机遇和挑战。文章通过分析辽宁海洋经济发展现状,梳理辽宁海洋经济发展的相关法律和政策,发现辽宁海洋经济要实现高质量发展还存在海洋经济供给侧结构性改革、海洋环境综合治理、海洋经济协同发展合作等方面的法律和政策缺失,应当加强海洋经济供给侧结构性改革的立法和政策保障,加快海洋经济协同发展合作和海洋环境综合治理的区域性法律与政策的制定,促进东北亚海洋经济协同发展,共同打造东北亚命运共同体。 相似文献
59.
Since the adoption of the 1969CLC and the 1971FC, the international oil-spill compensation regime has improved compensation for loss and damage caused by tanker oil spills. However, this regime has inherent limitations, such as protracted compensation payments and controversies over the scope and type of economic losses, including environmental damages, and the cost of environmental restoration. Therefore, given large oil-spill incidents, such as the Erika, Prestige, and Hebei Spirit, each government, respectively, has addressed compensation by enacting special laws or establishing domestic programs. This article contains a historical and legal analysis of the Hebei Spirit incident and discusses the limitations and necessary improvements to the international oil-spill compensation regime. 相似文献
60.
James R. Faulconbridge 《Geoforum》2007,38(5):925-940
For geographers, debates surrounding the knowledge economy have reinvigorated interest in the geographies of learning and knowledge production. Particularly topical are discussions of the possibility of spatially stretched (global) learning, something especially relevant to professional service firms where the production and management of knowledge across transnational organizational networks is essential. Taking this as its starting point, the paper explores the way knowledge is produced and circulated in transnational legal professional service firms. Drawing on the ideas of relational economic geography to analyse original empirical material, it highlights the way relational networks are socially constructed to allow learning to be stretched across space. The paper then goes on to identify the ‘politics’ of inclusion in these networks and the exclusivity of membership. It also highlights the geographies of power that influence the nature and effect of the knowledge produced and circulated. It does this by examining the role of relational knowledge networks in the ‘Americanization’ of legal practice in Europe and the impacts of such changes on national institutional and regulatory contexts. It is, therefore, argued that transnational corporate networks need to be viewed as heterogeneous and ‘embedded spaces of social practice’. It is shown that studying the actors and their interactions across relational networks is vital to fully understand how global relational forms are constructed and to understand their structuring effects on the global economy. 相似文献