A novel discharge device is designed on the basis of the configuration of micro-hollow cathode discharge （MHCD）. By using many MHCDs in parallel connection, a micro-discharge array can be constructed. With the micro...A novel discharge device is designed on the basis of the configuration of micro-hollow cathode discharge （MHCD）. By using many MHCDs in parallel connection, a micro-discharge array can be constructed. With the micro-discharge array, a high-pressure high-current density glow discharge plasmas can be formed to make a plasma display panel （PDP）. An air discharge experiment is finished with the discharge device. The stable direct current glow discharge is formed under the pressure from 20 Torr to 500 Torr. The voltage-current characteristic curve and the discharge photograph are noted. The voltage-current characteristic curve has a positive differential resistance coefficient on the whole discharge range. The estimated current density reaches 70.1A/cm^3, the power density is 3.6×10^4 W/cm^3, and the electron density is in the order of 10^13 cm^-3 at p = 200 Torr and ID = 10 mA. The experimental results indicate that the desiclned discharqe device is appropriate for PDP.展开更多
Gateways at faces of great mining heights are mostly driven along the roof of coal seams.For gateway height restrictions,a 1-3 m floor coal is retained,leaving a triangular floor coal at the face ends,causing a loss o...Gateways at faces of great mining heights are mostly driven along the roof of coal seams.For gateway height restrictions,a 1-3 m floor coal is retained,leaving a triangular floor coal at the face ends,causing a loss of coal.In order to improve coal recovery rates and to ensure efficiency of equipment at coal mining faces,we investigated suitable retention methods and recovery technology of floor coal at face ends.The upper floor coal can directly be recovered by a shearer with floor dinting.The lower floor coal is recovered by shearer with floor dinting after advanced floor dinting and retaining a step for protecting coal sides in a haulage gateway.Field practice shows that this method can improve the coal recovery rates at fully mechanized working faces with great mining heights.展开更多
This paper analyzes panel data from 2003–2012 to identify the factors driving the expansion of construction land in Ningbo city;it uses panel data,regional-level,and year-by-year regression models.The results indicat...This paper analyzes panel data from 2003–2012 to identify the factors driving the expansion of construction land in Ningbo city;it uses panel data,regional-level,and year-by-year regression models.The results indicate the following：（1） For each 1% increase in the size of the economy,urban population,and industrial structure adjustment coefficient,the amount of construction land increased by 0.35%,0.52% and –1%,respectively.（2） The factors driving the expansion of urban construction land differed across regions.In more highly developed areas such as Yuyao,Cixi,Fenghua and the downtown area,population growth was the most obvious driving factor with coefficients of 4.880,1.383,3.036 and 0.583,respectively,in those areas.Here,the impact of industrial structure adjustment was lower than that of population growth（with coefficients of 1.235,0.307,0.145 and –0.242）,while economic development was an increasingly insignificant factor（with coefficients of –0.302,0.071,0.037 and 0.297）.On the other hand,economic development was the most important factor for the expansion of construction land in relatively less developed areas such as Xiangshan and Ninghai counties with coefficients of 0.413 and 0.195,respectively.Here,population growth（with coefficients of –0.538 and 0.132） and industrial structure adjustment（with coefficients of –0.097 and 0.067） were comparatively weaker driving factors.（3） The results of the year-by-year regression indicate the increased impact of economic development as a driving factor（from –1.531 in 2005 to 1.459 in 2012）.The influence of the population growth factor slowly declined（from 1.249 in 2005 to 0.044 in 2012） and from 2009 on was less influential than the economic development factor.The industrial structure coefficient remained negative and its influence diminished from year to year（from –5.312 in 2004 to –0.589 in 2012）.展开更多
文摘A novel discharge device is designed on the basis of the configuration of micro-hollow cathode discharge （MHCD）. By using many MHCDs in parallel connection, a micro-discharge array can be constructed. With the micro-discharge array, a high-pressure high-current density glow discharge plasmas can be formed to make a plasma display panel （PDP）. An air discharge experiment is finished with the discharge device. The stable direct current glow discharge is formed under the pressure from 20 Torr to 500 Torr. The voltage-current characteristic curve and the discharge photograph are noted. The voltage-current characteristic curve has a positive differential resistance coefficient on the whole discharge range. The estimated current density reaches 70.1A/cm^3, the power density is 3.6×10^4 W/cm^3, and the electron density is in the order of 10^13 cm^-3 at p = 200 Torr and ID = 10 mA. The experimental results indicate that the desiclned discharqe device is appropriate for PDP.
基金the Independent Research of the State Key Laboratory of Coal Resources and Mine Safety(No. SKLCRSM09X02)the Open Research Fund of the State Key Laboratory of Coal Resources and Mine Safety(No.08KF12)the Graduate Students of Jiangsu Province Innovation Program Funded Projects(No.CX09B_120Z) for their financial support
文摘Gateways at faces of great mining heights are mostly driven along the roof of coal seams.For gateway height restrictions,a 1-3 m floor coal is retained,leaving a triangular floor coal at the face ends,causing a loss of coal.In order to improve coal recovery rates and to ensure efficiency of equipment at coal mining faces,we investigated suitable retention methods and recovery technology of floor coal at face ends.The upper floor coal can directly be recovered by a shearer with floor dinting.The lower floor coal is recovered by shearer with floor dinting after advanced floor dinting and retaining a step for protecting coal sides in a haulage gateway.Field practice shows that this method can improve the coal recovery rates at fully mechanized working faces with great mining heights.
基金National Key Research&Development Plan(2016YFA0602800)National Natural Science Foundation of China(41171110)
文摘This paper analyzes panel data from 2003–2012 to identify the factors driving the expansion of construction land in Ningbo city;it uses panel data,regional-level,and year-by-year regression models.The results indicate the following：（1） For each 1% increase in the size of the economy,urban population,and industrial structure adjustment coefficient,the amount of construction land increased by 0.35%,0.52% and –1%,respectively.（2） The factors driving the expansion of urban construction land differed across regions.In more highly developed areas such as Yuyao,Cixi,Fenghua and the downtown area,population growth was the most obvious driving factor with coefficients of 4.880,1.383,3.036 and 0.583,respectively,in those areas.Here,the impact of industrial structure adjustment was lower than that of population growth（with coefficients of 1.235,0.307,0.145 and –0.242）,while economic development was an increasingly insignificant factor（with coefficients of –0.302,0.071,0.037 and 0.297）.On the other hand,economic development was the most important factor for the expansion of construction land in relatively less developed areas such as Xiangshan and Ninghai counties with coefficients of 0.413 and 0.195,respectively.Here,population growth（with coefficients of –0.538 and 0.132） and industrial structure adjustment（with coefficients of –0.097 and 0.067） were comparatively weaker driving factors.（3） The results of the year-by-year regression indicate the increased impact of economic development as a driving factor（from –1.531 in 2005 to 1.459 in 2012）.The influence of the population growth factor slowly declined（from 1.249 in 2005 to 0.044 in 2012） and from 2009 on was less influential than the economic development factor.The industrial structure coefficient remained negative and its influence diminished from year to year（from –5.312 in 2004 to –0.589 in 2012）.
