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排序方式: 共有3453条查询结果,搜索用时 15 毫秒
11.
Hydrogeology Journal - Quantifying groundwater/surface-water interactions is essential for managing water resources and revealing contaminant fate. There has been little concern on the exchange... 相似文献
12.
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China Ocean Engineering - A consensus algorithm proposed in the paper is applied to tackle remarkable problems of unmeasurable velocities, the environmental disturbances, and the limited... 相似文献
14.
Chen Qiong Liu Fenggui Chen Ruijie Zhao Zhilong Zhang Yili Cui Peng Zheng Du 《地理学报(英文版)》2019,29(11):1859-1875
Journal of Geographical Sciences - The risk posed by natural disasters can be largely reflected by hazard and vulnerability. The analysis of long-term hazard series can reveal the mechanisms by... 相似文献
15.
The purpose of the present study is to investigate the performance and three-dimensional flow fields in a water-jet pump. TASCflow is employed to simulate the rotator-stator coupling flow field. A standard k-ε turbulence model combined with standard wall functions is used. In order to investigate the effect of a rear stator on flow fields, the flows in two water-jet pumps with and without a rear stator are studied. Computational fluid dynamics (CFD)-predicted overall performances are in good agreement with the experimental results. Then the flow fields, such as the pressure distribution on the blade surfaces, and the axial and tangential velocity distribution, especially the radial loading distribution, are investigated at different flow rates. In addition, the effects of a rear stator and different spacings between the rotor and the stator on the overall performance and the flow fields of the water-jet pump are also investigated. 相似文献
17.
同位素稀释中子活化分析铼与感耦等离子体质谱法测定锇相结合,应用于辉钼矿及铜_镍硫化物矿物的铼_锇年龄测定,取得了满意的结果,扩大了铼_锇测年法的应用范围。 相似文献
18.
沙漠砂抗剪强度特征及其与静力触探指标间的关系 总被引:2,自引:0,他引:2
通过室内系列化的直剪试验和静力触探模拟试验,对沙漠砂的抗剪强度特征取得了规律性的认识,并建立了砂土内摩擦角与锥尖阻力之间的经验关系,为今后在沙漠地基勘察评价中用静力触探方法估计砂土内摩擦角创造了条件。 相似文献
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20.
Du Jianguo 《中国地球化学学报》1992,11(3):237-243
Heat flow and the origin of helium in natural gases from fault basins of the continental rift-valley in eastern China are
discussed in terms of helium isotope geochemistry.3He/4He ratios in natural gases from the rift-valley range from 2.23 × 10−7 to 7.21 × 10−6, which are directly proportional to the concentration of helium and ΣNHC/ΣHC ratio in natural gases. Geological and isotope
geochemical data suggest that helium in natural gases consists predominantly of crustal radio-genic and upper mantle-derived
helium. In a simple mixing pattern between crustal He and mantle-derived He, mantle-derived helium in natural gases would
account for 10–60%. Calculated values for heat flow (Q) range from 59.7 to 82.4mWm−2, of which about 60 percent in the rift-valley is derived from the upper mantle. Natural helium reservoirs would be found
in the areas where the upper mantle uplifted greatly and heat flow is large in the continental rift-valley.
The project is financially supported by the National Natural Science Foundation of China. 相似文献