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881.
Huangshan(Yellowmountain)islocatedinsouthernpoofthelowerreaChesoftheYangtZemyer,30'31'Nand118"if'E.ItShigheStLotUSFlowerPeakis1864mabovesealevel.ItisoneofthetencelebretedscenicSPOtSinChinaandwasincludedintheWorldNaturalandCultulalHeritageListbyU'NESCOin1990.OneofthemajorreasonsforincludingitinthelistisbecauseofHuangshan'simPOrtantvalueforgeologicalacgeomorphicscienceicresearches.Inthe~es,Lee(1936)proPOsedthe"confinnatoryevidenceofPleistoceneglacinhonfromtheHuangshan"l'l.Inthesi…  相似文献   
882.
883.
Spatio-temporal variability of prokaryotic water column communities inside and outside a Polynesian tropical lagoon subjected to pearl oysters farming was assessed in terms of abundance by quantitative PCR and diversity by DGGE. Communities and operational taxonomic units (OTUs) were analysed according to dry/rainy seasons and free-living/particle-attached state. Bacterial density was higher in the lagoon compared to ocean and a seasonal trend was observed. No influence of the localisation within lagoon or of the planktonic/attached states was noticed on bacterial abundance and diversity. The OTUs belonged to Cyanobacteria, to heterotrophic groups in Proteobacteria and Flavobacteria. Archaeal abundance showed seasonal tendency and particle-prevalence, but no effect of lagoon or oceanic location was observed. Lagoon and oceanic archaeal diversity were different and Euryarchaeota (MG-II, MBG, and Halobacteria) were detected. During the dry season, planktonic and particle-associated community differed, whereas at rainy season, both communities were similar and included members usually associated with coral.  相似文献   
884.
Development of a system of indicators for sustainable port management   总被引:2,自引:0,他引:2  
The 1998 project ECOPORT, “Towards A Sustainable Transport Network”, developed by the Valencia Port Authority (VPA), established the bases for implementing an Environmental Management System (EMS) in industrial harbours. The use of data and information shall always be required to develop an efficient EMS. The objective of the present research (INDAPORT) study is to propose a system of sustainable environmental management indicators to be used by any port authorities. All activities performed within a port area are analysed for any potential environmental impacts and risks.

An environmental analysis of port activities has been carried out with the objective of designing the indicators system. Twenty-one corresponding activities have been identified for large industrial ports. Subsequently, the same methodology developed to date will be later applied to other Spanish and European ports. The study has been developed by using an original system and a methodology, which simultaneously use stage diagrams and systemic models (material and energy flow charts). Multi-criteria analysis techniques were used to evaluate potential impacts (identification of factors and evaluation of impacts).  相似文献   

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886.
本文描述了俄罗斯阿尔泰山Tongulack山的中压高温带状变质杂岩,讨论了应用岩浆侵入和流体模式解释其成因的方法。这个前寒武纪杂岩形成于500~700C和300~550 MPa。它是一个25~30 km宽的线状对称的变质带,是一个轴线弯曲的“热背斜”。岩石化学成分统计证明变质作用是等化学的。在这个变质杂岩中可分出4个带:绿泥石带(边缘)、堇青石带、夕线石带和无十字石带(中心)。这些带被等梯度带所分隔:堇青石、十字石出现或夕线石和十字石消失。可以认为,变质分带  相似文献   
887.
888.
Sediment cores (~40–100 cm) were collected at 12 locations in the western Bohai Bay, the Haihe River estuary, the Yongding River estuary and the Tianjin Harbor, China, during 24–26 July 2007, and analyzed for 7Be and 210Pb activities. Due to localized hydrodynamic patterns and frequent disturbance from dredging activities, steady-state sedimentation features were not observed in this study. As demonstrated in the 7Be and 210Pb profiles, the temporal and spatial variations of these radionuclides support a non-steady state depositional environment in the study area. By comparing 7Be and 210Pb inventories in the sediments with those of the atmospheric source, we found that: 1) sediments dredged from the Tianjin Harbor or eroded from nearby estuarine and coastal areas are retained in the western Bohai Bay for relatively short intervals (several months), as reflected in the relatively high 7Be inventories in the western Bohai Bay; 2) over the long-term (years to decades), 210Pb inventories in the sediments imply that there is a net on-shore transport of sediments, and the sediments are mass-balanced in the entire study area. Overall, our results suggest that the sediments are retained in the estuaries and the western Bohai Bay despite local variability in sediment dynamics and disturbance due to human activities.  相似文献   
889.
RATIONAL BASIS FOR SUSPENDED SEDIMENT MODELING   总被引:1,自引:0,他引:1  
This paper presents a rational basis to model the transport of suspended sediment. The loose-boundary condition for 3D models and the adjustment coefficients for both the depth-integrated 2D and laterally integrated 1D models are treated comprehensively. A combination of Dirichlet and Neumann conditions is proposed as the loose-boundary condition. The adjustment coefficient for 2D models is obtained on the basis of the proposed boundary condition and analytical solutions developed for some simple cases of non-equilibrium transport of sediment in uniform flows. The adjustment coefficient for 1D models for natural rivers is further obtained from lateral integration. Comparisons with analytical solutions and a considerable amount of laboratory and prototype data show that mathematical models developed along the proposed line of attack would well simulate the transport of suspended sediment in practical problems.  相似文献   
890.
古气候模拟进展   总被引:1,自引:0,他引:1       下载免费PDF全文
古气候模拟对研究古气候变化,检验模式模拟与现代气候状况完全不同的古气候的能力,以及未来气候预测等都具有重要的科学和社会意义.国际古气候对比项目(PMIP,Paleoclimate Modeling Intercomparison Project)开展十多年来,取得了许多成果,我国科学家在古气候模拟方面也做了相当的研究.本文通过介绍古气候模拟的方法,评述PMIP试验和其研究成果以及中国科学家所做的研究工作,以使人们更多地了解古气候模拟研究工作的重要意义.  相似文献   
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