Rock burst is one of the most catastrophic dynamic hazards in coal mining. A static and dynamic stresses superposition-based(SDSS-based) risk evaluation method of rock burst was proposed to pre-evaluate rock burst ris...Rock burst is one of the most catastrophic dynamic hazards in coal mining. A static and dynamic stresses superposition-based(SDSS-based) risk evaluation method of rock burst was proposed to pre-evaluate rock burst risk. Theoretical basis of this method is the stress criterion incurring rock burst and rock burst risk is evaluated according to the closeness degree of the total stress(due to the superposition of static stress in the coal and dynamic stress induced by tremors) with the critical stress. In addition, risk evaluation criterion of rock burst was established by defining the "Satisfaction Degree" of static stress. Furthermore,the method was used to pre-evaluate rock burst risk degree and prejudge endangered area of an insular longwall face in Nanshan Coal Mine in China. Results show that rock burst risk is moderate at advance extent of 97 m, strong at advance extent of 97-131 m,and extremely strong(i.e. inevitable to occur) when advance extent exceeds 131 m(mining is prohibited in this case). The section of two gateways whose floor abuts 15-3 coal seam is a susceptible area prone to rock burst. Evaluation results were further compared with rock bursts and tremors detected by microseismic monitoring. Comparison results indicate that evaluation results are consistent with microseismic monitoring, which proves the method's feasibility.展开更多
The Republic of Serbia is characterized by an unsatisfactory macroeconomic environment. Under the conditions of an evident shortage of liquid assets, the financial capital has moved from real to the financial sector, ...The Republic of Serbia is characterized by an unsatisfactory macroeconomic environment. Under the conditions of an evident shortage of liquid assets, the financial capital has moved from real to the financial sector, which led companies to over-indebtedness and shutdown of their own capacities. Therefore, capital investments largely depend on internal financing sources and the ability of companies to internally generate funds for investments. In this regard, an emphasis is placed on the difference in the assessment of the company＇s investment capacity based on internal financing sources, which are measured using static and dynamic indicators in order to prove the necessity of applying dynamic coefficients, which are unfortunately not present in our domestic practice. The paper examines and proves the advantages of the use of the dynamic approach for such analyses using the example of energy sector, which is one of the most important branches in Serbian economy.展开更多
The present paper reviews 25 studies conducted in the domain of L2 （second/foreign language） dynamic assessment （DA） in recent years. It begins with a survey of relevant research, then discusses some of the major ...The present paper reviews 25 studies conducted in the domain of L2 （second/foreign language） dynamic assessment （DA） in recent years. It begins with a survey of relevant research, then discusses some of the major findings and problems, and finishes with some suggestions for further research. The main findings of the review are as follows： （a） DA has the potential to promote L2 competence development; （b） both the interactionist approach and interventionist approach have attracted the interest of L2 researchers; （c） most studies have focused on small samples; （d） reading and grammatical knowledge have drawn the most attention; （e） group DA may be a potential method to advance L2 competence development in both the focused individual and the other members of the group; （f） computers might play a complementary role to humans acting as mediators; and （g） case study methodology has been the overwhelming choice for experimental design. Based on the available research, we suggest that additional studies are called for on the following issues： （a） L2 DA as an approach to measurement, （b） potential mediators, （c） validity issues of L2 DA, （d） the interface between DA and second language acquisition, and （e） the development of L2 classroom teachers.展开更多
基金Project(51174285)supported by the National Natural Science Foundation of China and the Shenhua Group Corporation Limited,ChinaProject(CXZZ12_0949)supported by the Research and Innovation Project for College Graduates of Jiangsu Province,ChinaProject(SZBF2011-6-B35)supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Rock burst is one of the most catastrophic dynamic hazards in coal mining. A static and dynamic stresses superposition-based(SDSS-based) risk evaluation method of rock burst was proposed to pre-evaluate rock burst risk. Theoretical basis of this method is the stress criterion incurring rock burst and rock burst risk is evaluated according to the closeness degree of the total stress(due to the superposition of static stress in the coal and dynamic stress induced by tremors) with the critical stress. In addition, risk evaluation criterion of rock burst was established by defining the "Satisfaction Degree" of static stress. Furthermore,the method was used to pre-evaluate rock burst risk degree and prejudge endangered area of an insular longwall face in Nanshan Coal Mine in China. Results show that rock burst risk is moderate at advance extent of 97 m, strong at advance extent of 97-131 m,and extremely strong(i.e. inevitable to occur) when advance extent exceeds 131 m(mining is prohibited in this case). The section of two gateways whose floor abuts 15-3 coal seam is a susceptible area prone to rock burst. Evaluation results were further compared with rock bursts and tremors detected by microseismic monitoring. Comparison results indicate that evaluation results are consistent with microseismic monitoring, which proves the method's feasibility.
文摘The Republic of Serbia is characterized by an unsatisfactory macroeconomic environment. Under the conditions of an evident shortage of liquid assets, the financial capital has moved from real to the financial sector, which led companies to over-indebtedness and shutdown of their own capacities. Therefore, capital investments largely depend on internal financing sources and the ability of companies to internally generate funds for investments. In this regard, an emphasis is placed on the difference in the assessment of the company＇s investment capacity based on internal financing sources, which are measured using static and dynamic indicators in order to prove the necessity of applying dynamic coefficients, which are unfortunately not present in our domestic practice. The paper examines and proves the advantages of the use of the dynamic approach for such analyses using the example of energy sector, which is one of the most important branches in Serbian economy.
基金part of the achievements of the project "Reform of Reading-to-Writing Courses of English Major,"supported by Guangdong Province Higher Educational Reform Essential Project(2013)the education reform project of Southern Medical University
文摘The present paper reviews 25 studies conducted in the domain of L2 （second/foreign language） dynamic assessment （DA） in recent years. It begins with a survey of relevant research, then discusses some of the major findings and problems, and finishes with some suggestions for further research. The main findings of the review are as follows： （a） DA has the potential to promote L2 competence development; （b） both the interactionist approach and interventionist approach have attracted the interest of L2 researchers; （c） most studies have focused on small samples; （d） reading and grammatical knowledge have drawn the most attention; （e） group DA may be a potential method to advance L2 competence development in both the focused individual and the other members of the group; （f） computers might play a complementary role to humans acting as mediators; and （g） case study methodology has been the overwhelming choice for experimental design. Based on the available research, we suggest that additional studies are called for on the following issues： （a） L2 DA as an approach to measurement, （b） potential mediators, （c） validity issues of L2 DA, （d） the interface between DA and second language acquisition, and （e） the development of L2 classroom teachers.
