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COMPARISON OF SOME LIMITS FOR STABILITY CLASSIFICATION
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作者 毕雪岩 刘烽 吴兑 《Journal of Tropical Meteorology》 SCIE 2005年第2期161-168,共8页
Stability parameters (Monin-Obukhov length L, gradient Richardson number Ri and bulk Rischardson number Ri), which are applicable in urban environment, were discussed for ways of calculating classification standards. ... Stability parameters (Monin-Obukhov length L, gradient Richardson number Ri and bulk Rischardson number Ri), which are applicable in urban environment, were discussed for ways of calculating classification standards. Gradient observations from a 325-m meteorological tower in Beijing are used to categorize Rib based on three different standards of stability proposed by D. Golder, Irwin and Houghton. The results show that it is relatively reasonable for the region of Beijing to apply the classification standard by Irwin. 展开更多
关键词 classification of atmospheric stability limit of stability classification BEIJING
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Applicable conditions for a classification system of aquifer-protective mining in hallow coal seams 被引量:4
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作者 Liu Yude Zhang Dongsheng +1 位作者 Fan Gangwei Yah Shoufeng 《Mining Science and Technology》 EI CAS 2011年第3期381-387,共7页
Based on the conclusions of domestic and foreign research, we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at th... Based on the conclusions of domestic and foreign research, we have analyzed the collapse-fall characteristics of overlying strata and the mechanism of aquifer-protective mining in shallow coal seam working faces at the Shendong Mine. We have selected the height of the water-conducting fracture zone in overlying strata as a composite index and established the applicable conditions of aquifer-protective mining in shallow coal seams with a multi-factor synthetic-index classification method. From our calculations and analyses of variance, we used factors such as the overlying strata strength, mining disturbing factors and rock integrity as related factors of the composite index. We have classified the applicable conditions of aquifer-protective mining in shallow coal seams into seven types by comparing the result of the height of water-conducting fractured zones of long-wall and short-wall working faces with the thickness of the bedrock, the thickness of the weathered zone and the size of safety coal-rock pillars. As a result, we propose the preliminary classification system of aquifer-protective mining in shallow coal seams. It can provide a theoretical guidance for safe applications of aquifer-protective mining technology in shallow coal seams under similar conditions. 展开更多
关键词 Depth limits of shallow coal seamsAquifer-protective mining Comprehensive classification index analysisWater-conducting cranny zone Analysis of variance
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The Method of Combined Inspection
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作者 Wei-qing Zhang Xiao-long Pu Yan Li 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2009年第2期235-242,共8页
For costly and/or destructive inspections for a complex population, the sum of observations, the test statistic in common use, is shown to be inefficient in risk control. For the complex population consisting of Berno... For costly and/or destructive inspections for a complex population, the sum of observations, the test statistic in common use, is shown to be inefficient in risk control. For the complex population consisting of Bernoulli distributions, the method of combined inspection is proposed in this paper, Evaluation based on examples and simulation results is conducted according to the method of limited classification. It is concluded that the new method is efficient and applicable. 展开更多
关键词 Method of combined inspection sampling inspection complex population overall classification limited classification
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