The two-parameter Weibull model is used to describe the fiber strength distribution.The stress carried by the intact and fracture fibers on the matrix crack plane during unloading/reloading is determined based on the ...The two-parameter Weibull model is used to describe the fiber strength distribution.The stress carried by the intact and fracture fibers on the matrix crack plane during unloading/reloading is determined based on the global load sharing criterion.The axial stress distribution of intact fibers upon unloading and reloading is determined based on the mechanisms of fiber sliding relative to matrix in the interface debonded region.The interface debonded length,unloading interface counter slip length,and reloading interface new slip length are obtained by the fracture mechanics approach.The hysteresis loops corresponding to different stresses considering fiber failure are compared with the cases without considering fiber failure.The effects of fiber characteristic strength and fiber Weibull modulus on the fiber failure,the shape,and the area of the hysteresis loops are analyzed.The predicted quasi-static unloading/reloading hysteresis loops agree well with experimental data.展开更多
Pai Town-Medog County Route is known as the first hiking route in China, which is a part of Tibet tourism product, as well as a business card of Linzhi tourism. The route is abundant with natural and human resources. ...Pai Town-Medog County Route is known as the first hiking route in China, which is a part of Tibet tourism product, as well as a business card of Linzhi tourism. The route is abundant with natural and human resources. In the research, quantitative and qualitative methods were integrated and scientific evaluation and analysis were made on tourism resources along the route according to National Standard of Classification, Investigation and Evaluation of Tourism Resources, with countermeasures proposed.展开更多
The optimum conditions for sulfur removal from coal by electrochemical reduction flotation in an aqueous NaCl solution were determined from orthogonal experiments. The effect of electrolytic conditions on the desulfur...The optimum conditions for sulfur removal from coal by electrochemical reduction flotation in an aqueous NaCl solution were determined from orthogonal experiments. The effect of electrolytic conditions on the desulfurization ratio was also studied. The electrochemical-reduction processed coal was examined by X-ray diffraction, Fourier transform infrared spectroscopy and wet chemical analysis. The results show that electrochemical reduction converts hydrophobic pyrite in Nantong coal into hydrophilic FeS and S2- and leads to an increase in the concentration of hydroxyl groups and aliphatic moieties and a corresponding decrease in carboxyl and carbonyl groups, which enhances the flotation desulfurization of the coal.展开更多
基金Supported by the National Natural Science Foundation of China(51075204)the Graduate Innovation Foundation of Jiangsu Province(CX08B-133Z)the Doctoral Innovation Foundation of Nanjing University of Aeronautics and Astronautics(BCXJ08-05)~~
文摘The two-parameter Weibull model is used to describe the fiber strength distribution.The stress carried by the intact and fracture fibers on the matrix crack plane during unloading/reloading is determined based on the global load sharing criterion.The axial stress distribution of intact fibers upon unloading and reloading is determined based on the mechanisms of fiber sliding relative to matrix in the interface debonded region.The interface debonded length,unloading interface counter slip length,and reloading interface new slip length are obtained by the fracture mechanics approach.The hysteresis loops corresponding to different stresses considering fiber failure are compared with the cases without considering fiber failure.The effects of fiber characteristic strength and fiber Weibull modulus on the fiber failure,the shape,and the area of the hysteresis loops are analyzed.The predicted quasi-static unloading/reloading hysteresis loops agree well with experimental data.
基金Supported by Resource Utilization Pattern Research of Tibet Southeastern Nature Reserve,Social science Project Tibet Department of Science and Technology~~
文摘Pai Town-Medog County Route is known as the first hiking route in China, which is a part of Tibet tourism product, as well as a business card of Linzhi tourism. The route is abundant with natural and human resources. In the research, quantitative and qualitative methods were integrated and scientific evaluation and analysis were made on tourism resources along the route according to National Standard of Classification, Investigation and Evaluation of Tourism Resources, with countermeasures proposed.
基金supported by the Special Fund for Major State Basic Research Program of China (Project 2004CB217601).
文摘The optimum conditions for sulfur removal from coal by electrochemical reduction flotation in an aqueous NaCl solution were determined from orthogonal experiments. The effect of electrolytic conditions on the desulfurization ratio was also studied. The electrochemical-reduction processed coal was examined by X-ray diffraction, Fourier transform infrared spectroscopy and wet chemical analysis. The results show that electrochemical reduction converts hydrophobic pyrite in Nantong coal into hydrophilic FeS and S2- and leads to an increase in the concentration of hydroxyl groups and aliphatic moieties and a corresponding decrease in carboxyl and carbonyl groups, which enhances the flotation desulfurization of the coal.
