With the increase in mining depth, the danger of coal and gas outbursts increases.In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration bo...With the increase in mining depth, the danger of coal and gas outbursts increases.In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration boreholes for draining of pressure relief gas.Based on the principle of overlying strata movement, deformation and pressure relief, a good effect of gas drainage was obtained.The practice in the Panyi coal mine has shown that, after mining the C11coal seam as the protective layer, the relative expansion deformation value of the protected layer C13 reached 2.63%, The permeability coefficient increased 2880 times, the gas drainage rate of the C13 coal seam increased to more than 60%, the amount of gas was reduced from 13.0 to 5.2 m3/t and the gas pressure declined from 4.4 to 0.4 MPa, which caused the danger the outbursts in the coal seams to be eliminated.The result was that we achieved a safe and highly efficient mining operation of the C13 coal seam.展开更多
The merging of optical communication and wireless communication is a tendency in the development of future communication.Orthogonal Frequency Division Multiplexing (OFDM) technology is becoming a core technology in th...The merging of optical communication and wireless communication is a tendency in the development of future communication.Orthogonal Frequency Division Multiplexing (OFDM) technology is becoming a core technology in the physical layer of next generation wireless communication system.Taking advantages of both wireless communication and optical communication,OFDM Radio over Fiber (OFDM-RoF) system is characterized by high speed,large capacity and high spectral efficiency.However,it still has some problems to be addressed,including dispersion and nonlinearity effects.The nonlinearity effect of fiber and modulator can be mitigated by PAPR reduction algorithms,the dispersion effect can be eliminated using Cyclic Prefix (CP) and channel estimation,and the fiber nonlinearity can be reduced by techniques such as digital phase conjugation,Partial Carrier Filling (PCF),nonlinearity precompensation and serial correlation reduction.展开更多
This Paper presents a valid innovation design method for electronic consuming products figures. Using the technology evaluation principle in TRIZ （theory of inventive problem solving） theory as a powerful tool, comb...This Paper presents a valid innovation design method for electronic consuming products figures. Using the technology evaluation principle in TRIZ （theory of inventive problem solving） theory as a powerful tool, combined with consumer psychology and relevant knowledge on products modeling methodology, evolution patterns and evolution paths of electronic consuming products figures have been explored. Moreover a set of regulations working for figures innovation design is established.展开更多
This paper introduces the development,compositions and characteristics of the domestic and foreign blowing-carding technique,discusses the technology of blowing-carding machines and the structures and functions of the...This paper introduces the development,compositions and characteristics of the domestic and foreign blowing-carding technique,discusses the technology of blowing-carding machines and the structures and functions of the main machines,analyses the production experiments of three types of blowing-carding flow lines in detail,and puts forward the effective measures to control the main quality index of blowing-carding sliver and the trend of blowing-carding technique development.展开更多
基金Projects 2005CB221503 supported by the National Basic Research Program of China70533050 and 50674089 by the National Natural Science Foundationof China
文摘With the increase in mining depth, the danger of coal and gas outbursts increases.In order to drain coal gas effectively and to eliminate the risk of coal and gas outbursts, we used a specific number of penetration boreholes for draining of pressure relief gas.Based on the principle of overlying strata movement, deformation and pressure relief, a good effect of gas drainage was obtained.The practice in the Panyi coal mine has shown that, after mining the C11coal seam as the protective layer, the relative expansion deformation value of the protected layer C13 reached 2.63%, The permeability coefficient increased 2880 times, the gas drainage rate of the C13 coal seam increased to more than 60%, the amount of gas was reduced from 13.0 to 5.2 m3/t and the gas pressure declined from 4.4 to 0.4 MPa, which caused the danger the outbursts in the coal seams to be eliminated.The result was that we achieved a safe and highly efficient mining operation of the C13 coal seam.
基金funded by the National Natural Science Foundation of China under Grant No.60877052by the National High Technology Research and Development Program of China("863" program)under Grant No.2009AA01Z220
文摘The merging of optical communication and wireless communication is a tendency in the development of future communication.Orthogonal Frequency Division Multiplexing (OFDM) technology is becoming a core technology in the physical layer of next generation wireless communication system.Taking advantages of both wireless communication and optical communication,OFDM Radio over Fiber (OFDM-RoF) system is characterized by high speed,large capacity and high spectral efficiency.However,it still has some problems to be addressed,including dispersion and nonlinearity effects.The nonlinearity effect of fiber and modulator can be mitigated by PAPR reduction algorithms,the dispersion effect can be eliminated using Cyclic Prefix (CP) and channel estimation,and the fiber nonlinearity can be reduced by techniques such as digital phase conjugation,Partial Carrier Filling (PCF),nonlinearity precompensation and serial correlation reduction.
基金Supported by Department of Science and Technology of Sichuan Province (No. 04JY029-001-2)
文摘This Paper presents a valid innovation design method for electronic consuming products figures. Using the technology evaluation principle in TRIZ （theory of inventive problem solving） theory as a powerful tool, combined with consumer psychology and relevant knowledge on products modeling methodology, evolution patterns and evolution paths of electronic consuming products figures have been explored. Moreover a set of regulations working for figures innovation design is established.
文摘This paper introduces the development,compositions and characteristics of the domestic and foreign blowing-carding technique,discusses the technology of blowing-carding machines and the structures and functions of the main machines,analyses the production experiments of three types of blowing-carding flow lines in detail,and puts forward the effective measures to control the main quality index of blowing-carding sliver and the trend of blowing-carding technique development.
