Hydraulic slotting in a gas drainage borehole is an effective method of enhancing gas drainage perfor- mance. However, it frequently occurs that a large amount of slotting products （mainly the coal slurry and gas） i...Hydraulic slotting in a gas drainage borehole is an effective method of enhancing gas drainage perfor- mance. However, it frequently occurs that a large amount of slotting products （mainly the coal slurry and gas） intensely spurt out of the borehole during the slotting, which adversely affects the slotting efficiency. Despite extensive previous investigations on the mechanism and prevention-device design of the spurt during ordinary borehole drilling, a very few studies has focused on the spurt in the s Ottlng pro ] ＂ _ cess. The slotting spurt is mainly caused by two reasons： the coal and gas outburst in the borehole and the borehole deslagging blockage. This paper focuses on the second reason, and investigates the hydraulic deslagging flow patterns in the annular space between the drill pipe and borehole wall Results show that there are six deslagging flow patterns when the drill pipe is still： pure slurry flow, pure gas flow, bubble flow, intermittent flow, layering flow and annular flow. When the drill pipe rotates, each of those six flow patterns changes due to the Taylor vortex effect. Outcomes of this study could help to better understand the slotting-spurt mechanism and provide guidance on the anti-spurt strategies through eliminating the borehole deslagging blockage.展开更多
Based on the coal demand under the 1.5 ℃ scenario, the amount of coal production in China was estimated in this study. According to the mutual relationship between the factors influencing coal production, an economet...Based on the coal demand under the 1.5 ℃ scenario, the amount of coal production in China was estimated in this study. According to the mutual relationship between the factors influencing coal production, an econometric model was constructed based on simultaneous equations, and the synergistic effect of each factor on the coal industry was estimated under the 1.5 ℃ scenario. Then, predictions were respectively made in the five aspects： coal production, coal science and technology progress, employment number, safe production level, and occupational health level, in different scenarios from 2016 to 2050. The results showed that before 2040, the comprehensive negative effect of the 1.5 ℃ situation is more than or equals to the positive effect. The 1.5 ℃ scenario has the biggest negative impact on employment, whose solution should be the focus. By 2050, the positive effects of the 1.5℃ scenario exceed the negative effect because of the enhancement in technical level and in the attention given to the whole production. Safety is improved, and health defects decline and the most obvious positive effect is on the ecological environment. The decrease of coal production will reduce the ecological environmental damage and significantly improve the ecological environment. In general, the prediction of 1.5 ℃ scenario promotes the increase of scientific production capacity and promotes the orderly development of coal. It has strengthened the safety and health protection degree, made the coal industry more efficient and competitive, and avoided or reduced the impact of coal development on the ecological environment and achieved environmental friendliness. However, the 1.5 ℃ situation also increases the employment pressure of the society, which affects the economic development of the major coal producing areas, but the situation can be overcome through the transformation and upgrading of the region. Finally, the impacts of various factors under the 1.5 ℃ scenario were evaluated through a unified comparison of the synergistic effect monetization using the cost and payment willingness methods. Based on the research results, suggestions on the regulation of coal production were proposed relating to resettlement of workers, protection of the ecological environment, and improvement of workers＇ health.展开更多
In order to implement the hierarchical training of core competence in accounting profession, above all we need to establish the positioning for personnel training in intermediate and advanced accounting profession. Ba...In order to implement the hierarchical training of core competence in accounting profession, above all we need to establish the positioning for personnel training in intermediate and advanced accounting profession. Based on the five major targeted vocational positions and its main task of accounting profession, this article has constructed the accounting vocational competence system, analyzed the correspondence between accounting profession＇ s core competencies and educational levels, and raised nine core competencies for the accounting profession, as well as the correspondence between the division of the breadth and depth of core competencies in vocational training and educational levels, with focus on the correspondence between the training breadth and depth of three key core accounting competencies and educational levels in the process of educational convergence.展开更多
The choice of the theme is explained by the constant interest in depiction of young protagonists among writers. Works of the last decades by writers of different generations served as material for this investigation：...The choice of the theme is explained by the constant interest in depiction of young protagonists among writers. Works of the last decades by writers of different generations served as material for this investigation： Ermakov and Polyanskaya, Dmitriev and Prilepin, Savelyev and Levental. The aim of this work is to observe the way in which the inner world of young protagonists, their interrelations and level of self-consciousness are depicted in novels and novellas by contemporary Russian writers. Through a range of examples of a variety of conflicts, in which the characters of the young protagonists are uncovered are examined： love, extreme circumstances, and professional life. Recent works are juxtaposed with earlier ones depending on the kind of test the young protagonists are put through. This analysis allows to state that the writers are not depicting the current generations as ＂lost＂, though they highlight loss and disappointment, the conflict between perceptions cultivated by reading and real life, and between the claim to being grown up and overt immaturity.展开更多
This article focuses on farm-tourist hosts and who they are in terms of education and competence. Gender is a central variable in the analysis. The analysis is based on an on-line survey of 448 farm tourist businesses...This article focuses on farm-tourist hosts and who they are in terms of education and competence. Gender is a central variable in the analysis. The analysis is based on an on-line survey of 448 farm tourist businesses conducted in spring 2009. In addition, a sample of women and men hosts on 19 farm tourism enterprises is interviewed. Women are more likely to be managers of farm tourism businesses, and have higher levels of formal education than men. Men are more likely to have vocational education, local attachment and competence obtained by growing up on a farm. Level of education does not have any significant impact on turnover, profitability and expected profit. As the businesses are small-scale and developed from the farms＇ material resources, the competence required is the ability to transform the farm resources into a tourist product. This competence might be achieved not only through formal educational, but also through previous work experiences, courses, networks, advisory services and daily experience. Interviews show that the hosts refer to their vocational backgrounds as important and relevant, and they refer to their practically obtained competence rather than to their educational backgrounds.展开更多
When running an experiment, inhomogeneity of the experimental units may result in poor estimations of treatment effects. Thus, it is desirable to select a good blocked design before running the experiment. Mostly, a s...When running an experiment, inhomogeneity of the experimental units may result in poor estimations of treatment effects. Thus, it is desirable to select a good blocked design before running the experiment. Mostly, a single block variable was used in the literature to treat the inhomogeneity for simplicity. However, in practice, the inhomogeneity often comes from multi block variables. Recently, a new criterion called B2-GMC was proposed for two-level regular designs with multi block variables. This paper proposes a systematic theory on constructing some B^2-GMC designs for the first time. Experimenters can easily obtain the B^2-GMC designs according to the construction method. Pros of B^2-GMC designs are highlighted in Section 4, and the designs with small run sizes are tabulated in Appendix B for practical use.展开更多
文摘Hydraulic slotting in a gas drainage borehole is an effective method of enhancing gas drainage perfor- mance. However, it frequently occurs that a large amount of slotting products （mainly the coal slurry and gas） intensely spurt out of the borehole during the slotting, which adversely affects the slotting efficiency. Despite extensive previous investigations on the mechanism and prevention-device design of the spurt during ordinary borehole drilling, a very few studies has focused on the spurt in the s Ottlng pro ] ＂ _ cess. The slotting spurt is mainly caused by two reasons： the coal and gas outburst in the borehole and the borehole deslagging blockage. This paper focuses on the second reason, and investigates the hydraulic deslagging flow patterns in the annular space between the drill pipe and borehole wall Results show that there are six deslagging flow patterns when the drill pipe is still： pure slurry flow, pure gas flow, bubble flow, intermittent flow, layering flow and annular flow. When the drill pipe rotates, each of those six flow patterns changes due to the Taylor vortex effect. Outcomes of this study could help to better understand the slotting-spurt mechanism and provide guidance on the anti-spurt strategies through eliminating the borehole deslagging blockage.
文摘Based on the coal demand under the 1.5 ℃ scenario, the amount of coal production in China was estimated in this study. According to the mutual relationship between the factors influencing coal production, an econometric model was constructed based on simultaneous equations, and the synergistic effect of each factor on the coal industry was estimated under the 1.5 ℃ scenario. Then, predictions were respectively made in the five aspects： coal production, coal science and technology progress, employment number, safe production level, and occupational health level, in different scenarios from 2016 to 2050. The results showed that before 2040, the comprehensive negative effect of the 1.5 ℃ situation is more than or equals to the positive effect. The 1.5 ℃ scenario has the biggest negative impact on employment, whose solution should be the focus. By 2050, the positive effects of the 1.5℃ scenario exceed the negative effect because of the enhancement in technical level and in the attention given to the whole production. Safety is improved, and health defects decline and the most obvious positive effect is on the ecological environment. The decrease of coal production will reduce the ecological environmental damage and significantly improve the ecological environment. In general, the prediction of 1.5 ℃ scenario promotes the increase of scientific production capacity and promotes the orderly development of coal. It has strengthened the safety and health protection degree, made the coal industry more efficient and competitive, and avoided or reduced the impact of coal development on the ecological environment and achieved environmental friendliness. However, the 1.5 ℃ situation also increases the employment pressure of the society, which affects the economic development of the major coal producing areas, but the situation can be overcome through the transformation and upgrading of the region. Finally, the impacts of various factors under the 1.5 ℃ scenario were evaluated through a unified comparison of the synergistic effect monetization using the cost and payment willingness methods. Based on the research results, suggestions on the regulation of coal production were proposed relating to resettlement of workers, protection of the ecological environment, and improvement of workers＇ health.
文摘In order to implement the hierarchical training of core competence in accounting profession, above all we need to establish the positioning for personnel training in intermediate and advanced accounting profession. Based on the five major targeted vocational positions and its main task of accounting profession, this article has constructed the accounting vocational competence system, analyzed the correspondence between accounting profession＇ s core competencies and educational levels, and raised nine core competencies for the accounting profession, as well as the correspondence between the division of the breadth and depth of core competencies in vocational training and educational levels, with focus on the correspondence between the training breadth and depth of three key core accounting competencies and educational levels in the process of educational convergence.
文摘The choice of the theme is explained by the constant interest in depiction of young protagonists among writers. Works of the last decades by writers of different generations served as material for this investigation： Ermakov and Polyanskaya, Dmitriev and Prilepin, Savelyev and Levental. The aim of this work is to observe the way in which the inner world of young protagonists, their interrelations and level of self-consciousness are depicted in novels and novellas by contemporary Russian writers. Through a range of examples of a variety of conflicts, in which the characters of the young protagonists are uncovered are examined： love, extreme circumstances, and professional life. Recent works are juxtaposed with earlier ones depending on the kind of test the young protagonists are put through. This analysis allows to state that the writers are not depicting the current generations as ＂lost＂, though they highlight loss and disappointment, the conflict between perceptions cultivated by reading and real life, and between the claim to being grown up and overt immaturity.
文摘This article focuses on farm-tourist hosts and who they are in terms of education and competence. Gender is a central variable in the analysis. The analysis is based on an on-line survey of 448 farm tourist businesses conducted in spring 2009. In addition, a sample of women and men hosts on 19 farm tourism enterprises is interviewed. Women are more likely to be managers of farm tourism businesses, and have higher levels of formal education than men. Men are more likely to have vocational education, local attachment and competence obtained by growing up on a farm. Level of education does not have any significant impact on turnover, profitability and expected profit. As the businesses are small-scale and developed from the farms＇ material resources, the competence required is the ability to transform the farm resources into a tourist product. This competence might be achieved not only through formal educational, but also through previous work experiences, courses, networks, advisory services and daily experience. Interviews show that the hosts refer to their vocational backgrounds as important and relevant, and they refer to their practically obtained competence rather than to their educational backgrounds.
基金supported by the National Natural Science Foundation of China under Grant Nos.11271205,11371223,11431006 and 11601244the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No.20130031110002+1 种基金the“131”Talents Program of Tianjinthe Program for Scientific Research Innovation Team in Applied Probability and Statistics of Qufu Normal University under Grant No.0230518
文摘When running an experiment, inhomogeneity of the experimental units may result in poor estimations of treatment effects. Thus, it is desirable to select a good blocked design before running the experiment. Mostly, a single block variable was used in the literature to treat the inhomogeneity for simplicity. However, in practice, the inhomogeneity often comes from multi block variables. Recently, a new criterion called B2-GMC was proposed for two-level regular designs with multi block variables. This paper proposes a systematic theory on constructing some B^2-GMC designs for the first time. Experimenters can easily obtain the B^2-GMC designs according to the construction method. Pros of B^2-GMC designs are highlighted in Section 4, and the designs with small run sizes are tabulated in Appendix B for practical use.
