The developing processes of stress and deformation fields of a protected layer after mining an upper-protective layer with a bow pseudo-incline technique were simulated to locate the protection region. The pressure re...The developing processes of stress and deformation fields of a protected layer after mining an upper-protective layer with a bow pseudo-incline technique were simulated to locate the protection region. The pressure relief of the protected layer was analyzed after mining the upper-protective layer. The pressure relief angle along the strike and incline were located according to the roles of protection of the deformation and stress pressure-relief of the protective layer after mining. This results show that the upper-protective layer with the bow pseudo-incline technique have an upper and downside pressure relief angle of 85 and 68 degrees respectively; the distribution of strike pressure relief angles along the pseudo-incline working face is uneven and their values range from 38.3 to 51 degrees. The pressure relief angle of the inclined middle location was the largest. The distribution of the protection region of the upper-protective layer with the bow pseudo-incline teelmique located by practical tests and numerical simulation is essentially consistent, compared with the results obtained by these methods.展开更多
Solar panels are oriented to the North （South） when the site is in the South （North） with a tilt angle close to the latitude. In the equatorial zone, the panels are quasi-horizontally arranged. This situation caus...Solar panels are oriented to the North （South） when the site is in the South （North） with a tilt angle close to the latitude. In the equatorial zone, the panels are quasi-horizontally arranged. This situation caused some problems： the panel is more rapidly covered with dust or salty mud that decreases its performance and degrades the protective glass. To overcome these difficulties, we evaluated theoretically and practically the energy lost by an incorrect tilt. The results are rather encouraging. Just 1.5% of total energy is lost when we tilted the panel at 10.0°. In practice, we realized that the loss of energy is fewer than we calculated it because of the reflected solar rays.展开更多
基金Projects PLN0610 supported by the Open Fund of State Key Lab of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University)HKLGF200706 by the Opening Project of Henan Key Laboratory of Coal Mine Methane and Fire Prevention+3 种基金50334060, 50474025 and 50774106 by the National Natural Science Foundation of China2005CB221502 by the National Basic Research Program of China50621403 by the Natural Science Innova-tion Group Foundation of ChinaCSTC, 2006BB7147, 2006AA7002 by the Natural Science Foundation of Chongqing
文摘The developing processes of stress and deformation fields of a protected layer after mining an upper-protective layer with a bow pseudo-incline technique were simulated to locate the protection region. The pressure relief of the protected layer was analyzed after mining the upper-protective layer. The pressure relief angle along the strike and incline were located according to the roles of protection of the deformation and stress pressure-relief of the protective layer after mining. This results show that the upper-protective layer with the bow pseudo-incline technique have an upper and downside pressure relief angle of 85 and 68 degrees respectively; the distribution of strike pressure relief angles along the pseudo-incline working face is uneven and their values range from 38.3 to 51 degrees. The pressure relief angle of the inclined middle location was the largest. The distribution of the protection region of the upper-protective layer with the bow pseudo-incline teelmique located by practical tests and numerical simulation is essentially consistent, compared with the results obtained by these methods.
文摘Solar panels are oriented to the North （South） when the site is in the South （North） with a tilt angle close to the latitude. In the equatorial zone, the panels are quasi-horizontally arranged. This situation caused some problems： the panel is more rapidly covered with dust or salty mud that decreases its performance and degrades the protective glass. To overcome these difficulties, we evaluated theoretically and practically the energy lost by an incorrect tilt. The results are rather encouraging. Just 1.5% of total energy is lost when we tilted the panel at 10.0°. In practice, we realized that the loss of energy is fewer than we calculated it because of the reflected solar rays.
