Mine dust is one of the main hazards in underground longwall mines worldwide.In order to solve the mine dust problem,a significant number of studies have been carried out regarding longwall mine dust control,both in C...Mine dust is one of the main hazards in underground longwall mines worldwide.In order to solve the mine dust problem,a significant number of studies have been carried out regarding longwall mine dust control,both in China and Australia.This paper presents a comparative study of dust control practices in Chinese and Australian longwall mines,with particular references to statutory limits,dust monitoring methods and dust management practices,followed by a brief discussion on the research status of longwall mine dust control in both countries.The study shows that water infusion,face ventilation controls,water sprays,and deep and wet cutting in longwall shearer operations are commonly practiced in almost all underground longwall mines and that both Chinese and Australian longwall mine dust control practices have their own advantages and disadvantages.It is concluded that there is a need for further development and innovative design of more effective dust mitigation products or systems despite the development of various dust control technologies.Based on the examinations and discussions,the authors have made some recommendations for further research and development in dust control in longwall mines.It is hoped that this comparative study will provide beneficial guidance for scholars and engineers who are engaging in longwall mine dust control research and practice.展开更多
Monodispersed magnetite Fe3O4 and hematite α-Fe2O3 nanocrystals have been grown in co-solvents of alcohol and water. Either the shape or the size of the nanocrystals could be easily controlled. Both the phases and na...Monodispersed magnetite Fe3O4 and hematite α-Fe2O3 nanocrystals have been grown in co-solvents of alcohol and water. Either the shape or the size of the nanocrystals could be easily controlled. Both the phases and nanostructures have been characterized by powder X-ray diffraction patterns and electron microscopy. The magnetic and catalytic properties of these products were investigated and compared with each other. The obtained results clearly demonstrate that these iron oxide nanocrystals are soft ferromagnetic at room temperature and α-Fe2O3 has a more effective catalytic property on the thermal decomposition of ammonium perchlorate than Fe3O4. Based on the experimental data, it is proposed that the magnetic and catalytic properties of these nanocrystals are dependent not only on the size and shape, but also on the surface structure of the nanocrystals. The nanoplates with significant anisotropic nanostructure demonstrate a highly enhanced performance as compared to nanoparticles.展开更多
基金supported by the Program for New Century Excellent Talents in University of China(No.NCET-10-0770)the financial support provided by the China Scholarship Council(Nos.201306425002&201406425048)the University of Wollongong to pursue study at the University of Wollongong as undergraduate visiting students
文摘Mine dust is one of the main hazards in underground longwall mines worldwide.In order to solve the mine dust problem,a significant number of studies have been carried out regarding longwall mine dust control,both in China and Australia.This paper presents a comparative study of dust control practices in Chinese and Australian longwall mines,with particular references to statutory limits,dust monitoring methods and dust management practices,followed by a brief discussion on the research status of longwall mine dust control in both countries.The study shows that water infusion,face ventilation controls,water sprays,and deep and wet cutting in longwall shearer operations are commonly practiced in almost all underground longwall mines and that both Chinese and Australian longwall mine dust control practices have their own advantages and disadvantages.It is concluded that there is a need for further development and innovative design of more effective dust mitigation products or systems despite the development of various dust control technologies.Based on the examinations and discussions,the authors have made some recommendations for further research and development in dust control in longwall mines.It is hoped that this comparative study will provide beneficial guidance for scholars and engineers who are engaging in longwall mine dust control research and practice.
基金supported by the National Natural Science Foundation of China, Guangdong Province, Guangzhou Citythe Ph.D. Programs Foundation of Ministry of Education of China (U0734002, 50872158, 8251027501000010, 2010GN-C011 & 20090171110025)
文摘Monodispersed magnetite Fe3O4 and hematite α-Fe2O3 nanocrystals have been grown in co-solvents of alcohol and water. Either the shape or the size of the nanocrystals could be easily controlled. Both the phases and nanostructures have been characterized by powder X-ray diffraction patterns and electron microscopy. The magnetic and catalytic properties of these products were investigated and compared with each other. The obtained results clearly demonstrate that these iron oxide nanocrystals are soft ferromagnetic at room temperature and α-Fe2O3 has a more effective catalytic property on the thermal decomposition of ammonium perchlorate than Fe3O4. Based on the experimental data, it is proposed that the magnetic and catalytic properties of these nanocrystals are dependent not only on the size and shape, but also on the surface structure of the nanocrystals. The nanoplates with significant anisotropic nanostructure demonstrate a highly enhanced performance as compared to nanoparticles.
