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31.
The Hexi Corridor is located at the transition zone of the Asian summer monsoon and westerly airflow, and lies in an important position in terms of its ecological fragility and climatic sensitivity. During a recent field expedition to this region, we found a sedimentary mirabilite layer in a number of localities including Suwushan, Yanchi, Baitujing, Yanchi Gaotai, Huahai, Yumen, Halanuo扙r, and Dunhuang (Fig. 1), which have the potential to provide important information about environmenta…  相似文献   
32.
通过对有限空间等间距水平顺排恒壁温管束外蓄冰过程的实验研究,揭示了环水温度和中管周围水温的变化特征和降温特点,明确了环水和上下管间水的降温过程存在的对流和密度反转现象,以及在蓄冷过程中管间流场的相互作用.实验结果表明在初始水温度较高时,环水和中上管间的水降温过程会存在明显的降温停滞现象,并出现不同温度的降温平台.降温停滞平台的长短与初始水温以及盐水温度的高低有关.  相似文献   
33.
通过对兰村水文站某一冰期水面蒸发实验和非冰期E601和D20蒸发器的水面蒸发发对比观测资料的分析,得出了冰期用E601半深、冰期与非冰期用D20注水深50mm蒸发器观测的蒸发量与E601型蒸发器量相关关系密切,折算九比较稳定的初步结论。  相似文献   
34.
冰盖下水流慢速流动时,大多数属于层流状态,尤其大体积水体流动时(如水库)更是如此。文章对层流条件下冰盖下输水时的N-S方程和能量方程进行了理论上的探讨,分析了冰盖下的水流速度场和温度场,结果表明,在概化的边界条件下,水流速度场是对称的抛物线分布,水流的温度场与水深的4次方成比例。  相似文献   
35.
36.
The electrical conductivity of H_2O at 0.21-4.18 GPa and 20 -350℃   总被引:2,自引:0,他引:2  
《科学通报(英文版)》1997,42(12):969-969
The electrical conductivity of H2O in solid and liquid phases has been measured at 0.21-4.18 GPa and 20-350℃. The results indicate: ( i ) different phases of H2O in solid have different relations between electrical conductivity and temperature and pressure. The conductivity changes continuously with temperature, but discontinuously with the pressure between 2.11 and 2.58 GPa, which corresponds to the transforming pressure between ice (Ⅵ) and ice ( Ⅶ ) ; ( ii ) the con-ductivity of H2O in liquid all increases with temperature and pressure, but there are discontinuities at pressures between 0.57 and 0.9 GPa, and between 2.11 and 2.58 GPa, which are also consistent with the polymorph of ice (ice ( Ⅴ), ice (Ⅵ) and ice ( Ⅶ ) ) . This reflects that H2O in liquid at different pressures has quite different properties of electron chemistry. It is prob-ably the important reason that causes the layers with high electrical conductivity and low velocity in the earth's crust and upper mantle.  相似文献   
37.
研究冰雪体育赛事品牌目的在于通过冰雪体育赛事品牌管理、品牌进化与品 牌进化绩效之间关系的探讨,发现路径影响关系,为促进冰雪体育赛事品牌提升提供参 考。以冰雪体育赛事品牌为研究对象,运用文献资料法、层次分析法等研究方法,构建冰 雪体育赛事品牌的层次结构模型,探讨冰雪体育赛事的品牌管理、品牌进化和进化绩效三 个层面的关系影响,获取冰雪体育赛事品牌管理、品牌进化和进化绩效的主要影响因素; 运用结构方程模型等研究方法,构建冰雪体育赛事品牌管理、品牌进化与进化绩效的关系 模型,分析验证路径影响关系。  相似文献   
38.
目的】为了减少海冰对平台生产所造成的影响,JZ9-3海域首次引用了全天候海冰气象监测系统。为了确保系统的正常运行,需要对系统进行可靠性评估。【方法】采用动态模糊故障树法,对全天候海冰气象监测系统的可靠性进行评估,同时提出初步的预防措施。【结果】通过应用动态模糊故障树对系统可靠性进行评估,获取了系统的薄弱环节,并提出了有效措施对薄弱环节加以控制。【结论】通过研究,有效地提高了系统的可靠性,这也是动态模糊故障树在国内的首次应用,为未来动态模糊故障树的广泛应用奠定基础。  相似文献   
39.
The behavior of water in close proximity to other materials under ambient conditions is of great significance due to its importance in a broad range of daily applications and scientific research. The structure and dynamics of water at an interface or in a nanopore are often significantly different from those of its bulk counterpart. Until recently, experimental access to these interfacial water structures was difficult to realize. The advent of two-dimensional materials, especially graphene, and the availability of various scanning probe microscopies were instrumental to visualize, characterize and provide fundamental knowledge of confined water. This review article summarizes the recent experimental and theoretical progress in a better understanding of water confined between layered Van der Waals materials. These results reveal that the structure and stability of the hydrogen bonded networks are determined by the elegant balance between water-surface and water-water interactions. The water-surface interactions often lead to structures that differ significantly from the conventional bilayer model of natural ice. Here, we review the current knowledge of water adsorption in different environments and intercalation within various confinements. In addition, we extend this review to cover the influence of interfacial water on the two-dimensional material cover and summarize the use of these systems in potential novel applications. Finally, we discuss emerged issues and identify some flaws in the present understanding.  相似文献   
40.
The temporal evolution of concentrations of dimethylsulphide (DMS), its precursor dimethylsulphoniopropionate (DMSP) and chlorophyll a is surveyed weekly in the water column and in a landfast ice core at a coastal station of Gerlache Inlet (Terra Nova Bay, Antarctica) from 27 November 2000 to 14 February 2001. The DMS and DMSP profile concentrations in the water column are similar and show a clear temporal trend, with minimum values (<0.7?nM) at all depths occurring on 27 November 2000 and maximum values (4.8 × 102?nM for DMS and 1.8 × 102?nM for DMSP) in surface water on 27 December 2000 for DMS and on 19 December 2000 for DMSP. When the sea-ice cover is present, the temporal evolution of DMSP closely follows that of chlorophyll a in the water column, supporting the idea that DMSP, and therefore DMS, has a phytoplanktonic origin. However, when the ice cover breaks up during the late austral summer, a second phytoplankton bloom occurs, while the DMSP concentration in the sea-water column remains very low. In the ice core, the results show higher concentrations of DMSP than those of the underlying sea water, highlighting the important role of sea ice in the sulphur cycle of the Antarctic ecosystem.  相似文献   
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