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
The empirical study uses black swan approach to analyze the performance of South African （ZA） listed property loan stocks （PLSs）. Although there are no empirical studies on black swan perspective and performance o...The empirical study uses black swan approach to analyze the performance of South African （ZA） listed property loan stocks （PLSs）. Although there are no empirical studies on black swan perspective and performance of listed real estate funds, the study found that there are similar traits of investing in listed real estate funds from emerging markets＇ perspective and what black swan advocates such as passive investment strategy and non-normality distribution of returns from listed real estate funds. Furthermore, the individual return of each fund was higher the return of the property loan stocks index and the probabilities of all variables confirm that they （variables） are significant when alpha is 10% at confidence level of 90%.展开更多
The relationship between the groundwater and the surface eco-environment in arid area is very close. In this paper, the authors extracted normalized difference vegetation index （NDVI） and vegetation conditional rat...The relationship between the groundwater and the surface eco-environment in arid area is very close. In this paper, the authors extracted normalized difference vegetation index （NDVI） and vegetation conditional ratio （VCR） from MODIS images, and analyzed the relationships among NDVI, VCR and the measured data of groundwater of the same location in the research region. Based on this, the depth of groundwater suitable for vegetation growth in the upper-middle reaches of the Yellow River basin has been calculated. The results show that the depth of groundwater suitable for vegetation growth in the research region ranges from 0.8 to 4.5m, and the optimal groundwater depth is 1.2m. The method developed in this study is applicable to research the relationship between the groundwater and land surface vegetation environment on large-scale in arid area.展开更多
2015.5 Recent price movement After trending higher from midMarch through the end of April,values for NY futures and the A Index turned lower in May.Chinese prices have been stable,while Indian and Pakistani prices inc...2015.5 Recent price movement After trending higher from midMarch through the end of April,values for NY futures and the A Index turned lower in May.Chinese prices have been stable,while Indian and Pakistani prices increased.Prices for the nearby July contract(NY futures)met resistance near 68 cents/展开更多
设{X_(ni):1≤i≤n,n≥1}为行间NA阵列,g(x)是R^+上指数为α的正则变化函数,r>0,m为正整数,{a_(ni):1≤i≤n,n≥1}为满足条件(?)|a_(ni)|=O((g(n))~1)的实数阵列,本文得到了使sum from n=1 to ∞n^(r-1)Pr(|■multiply from j=1 to m...设{X_(ni):1≤i≤n,n≥1}为行间NA阵列,g(x)是R^+上指数为α的正则变化函数,r>0,m为正整数,{a_(ni):1≤i≤n,n≥1}为满足条件(?)|a_(ni)|=O((g(n))~1)的实数阵列,本文得到了使sum from n=1 to ∞n^(r-1)Pr(|■multiply from j=1 to m a_(nij) X_(nij)|>ε)<∞,■ε>0成立的条件,推广并改进了Stout及王岳宝和苏淳等的结论。展开更多
Using the estimates of character sums over Galoi8 rings and the trace de-scription of primitive sequences over Z_(p^e), we obtain an estimate for the frequency of theoccurrences of any element in Z_(p^e) in one period...Using the estimates of character sums over Galoi8 rings and the trace de-scription of primitive sequences over Z_(p^e), we obtain an estimate for the frequency of theoccurrences of any element in Z_(p^e) in one period of a primitive sequence, which is betterthan Kuzmin's results if n >4e, where n is the degree of the generating polynomial ofthe primitive sequence.展开更多
In this paper, we discuss the 0, 1 distribution in the highest level sequence ae-1 of primitive sequence over Z2e generated by a primitive polynomial of degree n. First we get an estimate of the 0, 1 distribution by u...In this paper, we discuss the 0, 1 distribution in the highest level sequence ae-1 of primitive sequence over Z2e generated by a primitive polynomial of degree n. First we get an estimate of the 0, 1 distribution by using the estimates of exponential sums over Galois rings, which is tight for e relatively small to n. We also get an estimate which is suitable for e relatively large to n. Combining the two bounds, we obtain an estimate depending only on n, which shows that the larger n is, the closer to 1/2 the proportion of 1 will be.展开更多
Objective： To investigate the mechanism of electroacupuncturein treating chronic fatigue syndrome（CFS） in term of the neuro-endocrine system by observing the regulative effect of EA on hypothalamic-pituitary-adrena...Objective： To investigate the mechanism of electroacupuncturein treating chronic fatigue syndrome（CFS） in term of the neuro-endocrine system by observing the regulative effect of EA on hypothalamic-pituitary-adrenal index （HPA index） and corticotropin releasing hormone mRNA （CRH mRNA） in CFS model rats. Methods： The rats were randomly divided into control group, model group, and electroacupuncture group. Model and electroacupuncture groups were forced to swim in cold water to make CFS model, while rats in electroacupuncture group were treated with electroacupuncture treatment at the same time. Electroacupuncture group was given at Baihui（GV 20） and Zusanli（ST 36）. Evaluation of the model was processed according to the behavior changes of the rats. Hypothalamic, pituitary, and adrenal were weighted to calculate HPA index. CRH mRNA in hypothalamic was measured by fluorescence quantitative polymerase chain reaction （FQPCR）. Results： The model rats had behavior changes, and both physical and mental fatigue was observed. HPA index raised and expression of CRH mRNA in hypothalamus increased in CFS rats. After electroacupuncture treatment, the physical and mental fatigue was improved, and the hypothalamic index and CRH mRNA decreased significantly, while the pituitary and adrenal index only had little decrease. Conclusion： Cold water swim press could mimic the pathogenesis and make similar manifestations in rats with the common clinical symptoms. CFS has close relationship with increase of HPA index and CRH mRNA expression. Electroacupuncture can regulate the function of HPA axis to deal with CFS.展开更多
基金Financial support for this work, provided by the research fund of the North China Institute of Science and Technology (No.A09002)the National Natural Science Foundation of China (No.50834005)the National Basic Research Program of China (No.2007CB209402)
文摘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.
文摘The empirical study uses black swan approach to analyze the performance of South African （ZA） listed property loan stocks （PLSs）. Although there are no empirical studies on black swan perspective and performance of listed real estate funds, the study found that there are similar traits of investing in listed real estate funds from emerging markets＇ perspective and what black swan advocates such as passive investment strategy and non-normality distribution of returns from listed real estate funds. Furthermore, the individual return of each fund was higher the return of the property loan stocks index and the probabilities of all variables confirm that they （variables） are significant when alpha is 10% at confidence level of 90%.
文摘The relationship between the groundwater and the surface eco-environment in arid area is very close. In this paper, the authors extracted normalized difference vegetation index （NDVI） and vegetation conditional ratio （VCR） from MODIS images, and analyzed the relationships among NDVI, VCR and the measured data of groundwater of the same location in the research region. Based on this, the depth of groundwater suitable for vegetation growth in the upper-middle reaches of the Yellow River basin has been calculated. The results show that the depth of groundwater suitable for vegetation growth in the research region ranges from 0.8 to 4.5m, and the optimal groundwater depth is 1.2m. The method developed in this study is applicable to research the relationship between the groundwater and land surface vegetation environment on large-scale in arid area.
文摘2015.5 Recent price movement After trending higher from midMarch through the end of April,values for NY futures and the A Index turned lower in May.Chinese prices have been stable,while Indian and Pakistani prices increased.Prices for the nearby July contract(NY futures)met resistance near 68 cents/
文摘设{X_(ni):1≤i≤n,n≥1}为行间NA阵列,g(x)是R^+上指数为α的正则变化函数,r>0,m为正整数,{a_(ni):1≤i≤n,n≥1}为满足条件(?)|a_(ni)|=O((g(n))~1)的实数阵列,本文得到了使sum from n=1 to ∞n^(r-1)Pr(|■multiply from j=1 to m a_(nij) X_(nij)|>ε)<∞,■ε>0成立的条件,推广并改进了Stout及王岳宝和苏淳等的结论。
文摘Using the estimates of character sums over Galoi8 rings and the trace de-scription of primitive sequences over Z_(p^e), we obtain an estimate for the frequency of theoccurrences of any element in Z_(p^e) in one period of a primitive sequence, which is betterthan Kuzmin's results if n >4e, where n is the degree of the generating polynomial ofthe primitive sequence.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.19971096,90104035).
文摘In this paper, we discuss the 0, 1 distribution in the highest level sequence ae-1 of primitive sequence over Z2e generated by a primitive polynomial of degree n. First we get an estimate of the 0, 1 distribution by using the estimates of exponential sums over Galois rings, which is tight for e relatively small to n. We also get an estimate which is suitable for e relatively large to n. Combining the two bounds, we obtain an estimate depending only on n, which shows that the larger n is, the closer to 1/2 the proportion of 1 will be.
文摘Objective： To investigate the mechanism of electroacupuncturein treating chronic fatigue syndrome（CFS） in term of the neuro-endocrine system by observing the regulative effect of EA on hypothalamic-pituitary-adrenal index （HPA index） and corticotropin releasing hormone mRNA （CRH mRNA） in CFS model rats. Methods： The rats were randomly divided into control group, model group, and electroacupuncture group. Model and electroacupuncture groups were forced to swim in cold water to make CFS model, while rats in electroacupuncture group were treated with electroacupuncture treatment at the same time. Electroacupuncture group was given at Baihui（GV 20） and Zusanli（ST 36）. Evaluation of the model was processed according to the behavior changes of the rats. Hypothalamic, pituitary, and adrenal were weighted to calculate HPA index. CRH mRNA in hypothalamic was measured by fluorescence quantitative polymerase chain reaction （FQPCR）. Results： The model rats had behavior changes, and both physical and mental fatigue was observed. HPA index raised and expression of CRH mRNA in hypothalamus increased in CFS rats. After electroacupuncture treatment, the physical and mental fatigue was improved, and the hypothalamic index and CRH mRNA decreased significantly, while the pituitary and adrenal index only had little decrease. Conclusion： Cold water swim press could mimic the pathogenesis and make similar manifestations in rats with the common clinical symptoms. CFS has close relationship with increase of HPA index and CRH mRNA expression. Electroacupuncture can regulate the function of HPA axis to deal with CFS.
