In order to realize the safety, high efficiency and rapidity of hard rock tunneling, we propose the drilling &hydraulic impact hard-rock tunneling(DHIHT) technology and method. Based on the LS-DYNA explicit module...In order to realize the safety, high efficiency and rapidity of hard rock tunneling, we propose the drilling &hydraulic impact hard-rock tunneling(DHIHT) technology and method. Based on the LS-DYNA explicit module and APDL programming, the key parameters of DHIHT, including drilling spacing and drilling radius, were investigated. The simulation results show that: the drilling spacing should not exceed0.20 m-larger distances weaken the actual breaking effect; the best drilling radius is about 0.035 m, larger or smaller distances would both decrease the effect of drilling-hole free surfaces. The field impact breaking experiments were conducted in Baitaizi township granite quarry, Jinzhou, Liaoning province,China. The experiment results indicate that DHIHT is a feasible method for hard-rock tunneling, but its efficiency still needs to be further optimized and improved.展开更多
The semi-classical black hole tunneling radiation (Parikh-Wilczek tunneling proposal) is calculated undera minimal length uncertainty analysis.It is shown that,the generalized second law of thermodynamics may bound th...The semi-classical black hole tunneling radiation (Parikh-Wilczek tunneling proposal) is calculated undera minimal length uncertainty analysis.It is shown that,the generalized second law of thermodynamics may bound thetunneling probability radiation of a Reissner-Nordstrom black hole radiation.展开更多
In order to improve the thermal environment of high-temperature heading face,moisture content of supply air is reduced by dehumidification, and the relative humidity ofenvironment air of the heading face is also decre...In order to improve the thermal environment of high-temperature heading face,moisture content of supply air is reduced by dehumidification, and the relative humidity ofenvironment air of the heading face is also decreased.First, according to the coefficient ofperformance of dehumidifier, the capacity of dehumidification was calculated.Second, inthe engineering example of the heading face, quantitative changes of WBGT (Wet BulbGlobe Temperature) were compared between with dehumidification and without dehumidification.Based on WBGT standards, the thermal comfort of high-temperature environmentof heading face was evaluated between with dehumidification and without handling.Reducingthe relative humidity of airflow through dehumidification, the thermal comfort of ahigh-temperature environment of heading face can improve greatly.Even if dry bulb temperatureof airflow is not decreased, the thermal comfort of heading face environment isalso improved to some extent.展开更多
基金supported by the Staring Project of Youth Team of Taiyuan University of Technology (No. 2013T036)the Qualified Personnel Foundation of Taiyuan University of Technology (No. TYUT-RC201426a)the 2014 Shanxi Coal-based Key Scientific & Technological Project (No. MJ2014-06)
文摘In order to realize the safety, high efficiency and rapidity of hard rock tunneling, we propose the drilling &hydraulic impact hard-rock tunneling(DHIHT) technology and method. Based on the LS-DYNA explicit module and APDL programming, the key parameters of DHIHT, including drilling spacing and drilling radius, were investigated. The simulation results show that: the drilling spacing should not exceed0.20 m-larger distances weaken the actual breaking effect; the best drilling radius is about 0.035 m, larger or smaller distances would both decrease the effect of drilling-hole free surfaces. The field impact breaking experiments were conducted in Baitaizi township granite quarry, Jinzhou, Liaoning province,China. The experiment results indicate that DHIHT is a feasible method for hard-rock tunneling, but its efficiency still needs to be further optimized and improved.
文摘The semi-classical black hole tunneling radiation (Parikh-Wilczek tunneling proposal) is calculated undera minimal length uncertainty analysis.It is shown that,the generalized second law of thermodynamics may bound thetunneling probability radiation of a Reissner-Nordstrom black hole radiation.
基金Supported by Hunan Province Science and Technology(2007FJ1012)the Scientific Research Fund of Hunan Provincial Education Department(09CY014)Doctoral Fund of HNUST
文摘In order to improve the thermal environment of high-temperature heading face,moisture content of supply air is reduced by dehumidification, and the relative humidity ofenvironment air of the heading face is also decreased.First, according to the coefficient ofperformance of dehumidifier, the capacity of dehumidification was calculated.Second, inthe engineering example of the heading face, quantitative changes of WBGT (Wet BulbGlobe Temperature) were compared between with dehumidification and without dehumidification.Based on WBGT standards, the thermal comfort of high-temperature environmentof heading face was evaluated between with dehumidification and without handling.Reducingthe relative humidity of airflow through dehumidification, the thermal comfort of ahigh-temperature environment of heading face can improve greatly.Even if dry bulb temperatureof airflow is not decreased, the thermal comfort of heading face environment isalso improved to some extent.
