L3414 mechanized mining working face (No.14 coal seam) of Lingxin Mine is under the Xitian River.The mining disturbed zone where rock properties and conditions have been changed due to mining, the safety and environme...L3414 mechanized mining working face (No.14 coal seam) of Lingxin Mine is under the Xitian River.The mining disturbed zone where rock properties and conditions have been changed due to mining, the safety and environmental protection were con- cemed greatly. Based on engineering geological environment of L3414 working face and mining factors, the color bore-bole TV inspecting, leakage of drilling fluid monitoring, simulation experiment, numerical computing, in-situ ground stress measurement and subsidence measurement, etal, these programs contribute to the formation of a scientific basis for control water safe mining and normal mining or environmental protection in the condition of existing fully-mechanized mining.展开更多
The explosive reaction degree and protection from explosions are concerns in the military field.In this work,the reaction degree of the composition B explosive was investigated experimentally.Multi-layered compound st...The explosive reaction degree and protection from explosions are concerns in the military field.In this work,the reaction degree of the composition B explosive was investigated experimentally.Multi-layered compound structures were used as barriers to weaken the blast loads.A comprehensive experiment using a high-speed camera and image processing techniques,side witness plates,and bottom witness plates was presented.Using the experimental fragment velocities,fragment piercing patterns,and damage characteristics,the reaction degree of the explosive impeded by different multi-layered compound structures could be precisely differentiated.Reaction parameters of the explosive obstructed by compound structures were obtained by theoretical analysis and numerical simulations.Unlike the common method in which the explosive reaction degree is only distinguished based on the initial pressure amplitude transmitted into the explosive,a following shock wave reflected from the side steel casing was also considered.Different detonation growth paths in the explosive formed.Therefore,all these shock wave propagation characteristics must be considered to analyze the explosive response impeded by compound structures.展开更多
Pharmaceutical comprehensive study(PCS) is a new system of experimental teaching in China, which integrates multidisciplinary pharmaceutical knowledge and covers the basic process of new drug discovery. To explore the...Pharmaceutical comprehensive study(PCS) is a new system of experimental teaching in China, which integrates multidisciplinary pharmaceutical knowledge and covers the basic process of new drug discovery. To explore the feasibility of this experiment teaching system and mode, we developed PCS as an elective course. The PCS is designed with two sections: pharmaceutical comprehensive design(PCD) and pharmaceutical comprehensive experiment(PCE). The PCD section includes literature review, comprehensive project design and oral examination. PCE can be divided into four parts: synthesis, quantitative determination, pharmacodynamic evaluation, and formulation and quality determination. Course grade was determined by experimental performance, written report, literature review, new project design and oral examination. The learning interest, experimental ability, theoretical level and literature retrieval ability, team spirit and interpersonal skills have been all significantly improved among students taking this course. A survey was administered at the end of the semester to the enrolled students. The responses were reported as percentages, and the feedback was positive. The course was highly recommended by the teaching inspection committee. This new course plays an important role in developing students’ creativity and comprehensive ability. It could help students understand the focus and features of every secondary discipline, as well as establish scientific and reasonable knowledge system. Most students can better understand the process of drug research after this course.展开更多
基金Supported by National Science Foundation(10402033) Ministry of Education Key Lab.of West Mining and Hazard Control Key Research Founda-tion(04JS19) and Shaanxi Province Natural Science (2003E213)
文摘L3414 mechanized mining working face (No.14 coal seam) of Lingxin Mine is under the Xitian River.The mining disturbed zone where rock properties and conditions have been changed due to mining, the safety and environmental protection were con- cemed greatly. Based on engineering geological environment of L3414 working face and mining factors, the color bore-bole TV inspecting, leakage of drilling fluid monitoring, simulation experiment, numerical computing, in-situ ground stress measurement and subsidence measurement, etal, these programs contribute to the formation of a scientific basis for control water safe mining and normal mining or environmental protection in the condition of existing fully-mechanized mining.
基金The authors are very grateful for the support received from the National Natural Science Foundation of China(No.11872121).
文摘The explosive reaction degree and protection from explosions are concerns in the military field.In this work,the reaction degree of the composition B explosive was investigated experimentally.Multi-layered compound structures were used as barriers to weaken the blast loads.A comprehensive experiment using a high-speed camera and image processing techniques,side witness plates,and bottom witness plates was presented.Using the experimental fragment velocities,fragment piercing patterns,and damage characteristics,the reaction degree of the explosive impeded by different multi-layered compound structures could be precisely differentiated.Reaction parameters of the explosive obstructed by compound structures were obtained by theoretical analysis and numerical simulations.Unlike the common method in which the explosive reaction degree is only distinguished based on the initial pressure amplitude transmitted into the explosive,a following shock wave reflected from the side steel casing was also considered.Different detonation growth paths in the explosive formed.Therefore,all these shock wave propagation characteristics must be considered to analyze the explosive response impeded by compound structures.
基金The Education and Teaching Research Project of Peking University Health Science Center
文摘Pharmaceutical comprehensive study(PCS) is a new system of experimental teaching in China, which integrates multidisciplinary pharmaceutical knowledge and covers the basic process of new drug discovery. To explore the feasibility of this experiment teaching system and mode, we developed PCS as an elective course. The PCS is designed with two sections: pharmaceutical comprehensive design(PCD) and pharmaceutical comprehensive experiment(PCE). The PCD section includes literature review, comprehensive project design and oral examination. PCE can be divided into four parts: synthesis, quantitative determination, pharmacodynamic evaluation, and formulation and quality determination. Course grade was determined by experimental performance, written report, literature review, new project design and oral examination. The learning interest, experimental ability, theoretical level and literature retrieval ability, team spirit and interpersonal skills have been all significantly improved among students taking this course. A survey was administered at the end of the semester to the enrolled students. The responses were reported as percentages, and the feedback was positive. The course was highly recommended by the teaching inspection committee. This new course plays an important role in developing students’ creativity and comprehensive ability. It could help students understand the focus and features of every secondary discipline, as well as establish scientific and reasonable knowledge system. Most students can better understand the process of drug research after this course.
