＂U＂ and ＂U＋I＂ type ventilation experiments were performed on a three-dimensional fully mechanized caving face simulation experimental platform. The distribution laws of the pressure field and gas field in the min...＂U＂ and ＂U＋I＂ type ventilation experiments were performed on a three-dimensional fully mechanized caving face simulation experimental platform. The distribution laws of the pressure field and gas field in the mine goal were obtained. Results show that the flow field in the goaf is generally asymmetric; the location of the gas accumulation area changes with ventilation parameters and can be used as an evaluation indicator to study the air leakage extent in the goal. Hence, drainage pipes buried in the goaf to intensively extract gas can be designed in such gas areas, which can give considerations in both improving gas drainage efficiency and reducing air leakage. By comparing the gas extraction effect of model experiments with that of on-site underground practices, the basic laws are commonly consistent according to comparative analysis. Thus the experimental results can be used to guide the application of underground gas prevent!o_n_and.control..展开更多
On the basis of data from the 2008 Chinese General Social Survey, this paper analyzes the changing organizational job mobility patterns of members of society in a segmented labor market. The structure of labor market ...On the basis of data from the 2008 Chinese General Social Survey, this paper analyzes the changing organizational job mobility patterns of members of society in a segmented labor market. The structure of labor market segmentation is based on differences in the power of different labor sectors to distribute social resources, leading to further differences in their power of ＂attraction＂ or ＂repulsion＂ that influence people＇s organizational mobility. These forces are strongest in the primary labor market, lessening the possibility that workers will leave their jobs and raising the possibility of cross-sector mobility. In the course of China＇s market transition, changes in the power to allocate social resources have entailed changes in the structure of labor market segmentation, changes that have been reflected in organizational mobility. Our examination of changing modes of organizational mobility reveals that the structure of urban labor market segmentation has changed from being mainly systemic at the outset of reform and opening up to the current coexistence of systemic segmentation and market segmentation.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 51174198 and 51304203)Supported by State Key Laboratory of Coal Resources and Safe Mining (No. SKLCRSM11X01)
文摘＂U＂ and ＂U＋I＂ type ventilation experiments were performed on a three-dimensional fully mechanized caving face simulation experimental platform. The distribution laws of the pressure field and gas field in the mine goal were obtained. Results show that the flow field in the goaf is generally asymmetric; the location of the gas accumulation area changes with ventilation parameters and can be used as an evaluation indicator to study the air leakage extent in the goal. Hence, drainage pipes buried in the goaf to intensively extract gas can be designed in such gas areas, which can give considerations in both improving gas drainage efficiency and reducing air leakage. By comparing the gas extraction effect of model experiments with that of on-site underground practices, the basic laws are commonly consistent according to comparative analysis. Thus the experimental results can be used to guide the application of underground gas prevent!o_n_and.control..
文摘On the basis of data from the 2008 Chinese General Social Survey, this paper analyzes the changing organizational job mobility patterns of members of society in a segmented labor market. The structure of labor market segmentation is based on differences in the power of different labor sectors to distribute social resources, leading to further differences in their power of ＂attraction＂ or ＂repulsion＂ that influence people＇s organizational mobility. These forces are strongest in the primary labor market, lessening the possibility that workers will leave their jobs and raising the possibility of cross-sector mobility. In the course of China＇s market transition, changes in the power to allocate social resources have entailed changes in the structure of labor market segmentation, changes that have been reflected in organizational mobility. Our examination of changing modes of organizational mobility reveals that the structure of urban labor market segmentation has changed from being mainly systemic at the outset of reform and opening up to the current coexistence of systemic segmentation and market segmentation.
