The site drilling packer permeability test and TEM to the 2100 workface in Gucheng coalmine determined the two-zone height under sublevel strip mining.The conclusion considers that the lying strata deterioration law o...The site drilling packer permeability test and TEM to the 2100 workface in Gucheng coalmine determined the two-zone height under sublevel strip mining.The conclusion considers that the lying strata deterioration law of the strip mining is similar to that of the sublevel mining.Thus, against that the actually measured data lacked, it is feasible to refer to the reservation of the waterproof coal pillar in the neighbor coalmine under sublevel situation.However, it is necessary to further launch the research on lying strata deterioration law under sublevel striping mining for the purpose of providing the right foundation for the layout of the workface not mined so far and the reservation of the waterproof coal pillar in the mining area.展开更多
We studied variations in the stress field around guide holes drilled during tunnel excavation to understand the mechanical mechanism by which these holes help prevent rockburst.The study used elasto-plastic analysis o...We studied variations in the stress field around guide holes drilled during tunnel excavation to understand the mechanical mechanism by which these holes help prevent rockburst.The study used elasto-plastic analysis of a circular chamber under non-axisymmetrical loads.The results showed that the unloading of in-situ stresses, and the forming of a secondary stress field, leads to a severe change in the stress field around the guide holes.This causes the formation of an X-shaped area of plastic deformation, which prevents the rockburst.Adopting a sub-model finite element technique, we analyzed the factors that influence the distribution of the plastic area, such as the guide hole distribution and the in-situ stress state.The calculations showed that higher initial stresses result in greater adjustment to the stress field.When the stress concentration is greater the size of the plastic area surrounding the guide hole is larger.A multi-row distribution of the guide holes shaped like a quincunx can increase the interconnectivity of the plastic areas and allow the plastic area to extend from the tunnel wall deep into the surrounding rock.An optimized design was put forward based on the distribution of the plastic area around guide holes and the factors that influence it.展开更多
With the mine exploitation depth getting deeper and deeper, the mine heat-harm turns into another natural disaster after the five disasters, which are the roof, the gas, the fire, the dust and the flood disaster. Comp...With the mine exploitation depth getting deeper and deeper, the mine heat-harm turns into another natural disaster after the five disasters, which are the roof, the gas, the fire, the dust and the flood disaster. Compared with other researches on prevention and cure against the heat-harm, the research on prevention and cure against the heat-harm in constructing mine are less. Referring to the experience of prevention and cure against the heat-harm home and ＇abroad, analyzing the characteristic of cooling in the constructing mine, and based on the ground former freezing equipments and the modified mine temporary cooling equipments, the paper proposed four technical projects. By comparing with the four technical projects, the second project is preponderant both in technology and economy and can solve the heat-harm of the constructing mine, which is proved by the forecast and calculation. The project can be widely applied in de-temperature tasks of high temperature and heat-harm mines during the mine constructing period and in the exploiting preparing phase.展开更多
According to the characteristic of clay aquiclude of overburden,the proper simulation materials and proportions of mixture for simulating the plastic clay aquiclude layers were developed,and the plastic similarity con...According to the characteristic of clay aquiclude of overburden,the proper simulation materials and proportions of mixture for simulating the plastic clay aquiclude layers were developed,and the plastic similarity conditions were setup.Thus,the simili- tude and simulation method in whole stress-strain was progressed.Furthermore,the simulation condition and material proportions in water reaction property and crack closing property were also put forward.Based on systematical tests,the development and distri- bution of mined cracks in roof and subsurface aquiclude was found and the stability of aquiclude was analyzed at all.At last,the key section and key index of aquclude stability was advanced.It is found that the movement of clay aquiclude follows the movement of the underlying bedrock layers.The basic caving mechanism of the overburden roof strata was also presented.展开更多
This paper studies the effect of ground stress, pore gas pressure and adsorbed methane on methane transport in coal seam. and researches into the applleability of Darey’s inw to methane transport. The additional expa...This paper studies the effect of ground stress, pore gas pressure and adsorbed methane on methane transport in coal seam. and researches into the applleability of Darey’s inw to methane transport. The additional expansion stress of coal induced by adsorbed methane is measured. The paper establishes the constitutive equation of methane transport, taking ground stress, pore gas pressure and Klinkenburg’s effects into consideration. The features of methane transport under the condition of given stress or strain have been analyzed.展开更多
The light weight heat treated B-grade bulletproof steel was developed through composition design and optimization based on multiplex alloying,multiplex micro-alloying design ideas and complex phase structure strengthe...The light weight heat treated B-grade bulletproof steel was developed through composition design and optimization based on multiplex alloying,multiplex micro-alloying design ideas and complex phase structure strengthening theory.The puzzle how to avoid the quenching deformation problem of super high strength thin sheet was solved through heat treatment in a die with a set of cooling system.Such B-grade bulletproof steel plate has fine tempered lath martensite structure.The shooting and certification test results showed that the shoot resistance of B-grade bulletproof steel plate can meet the protection demand of Protection specification for cash carrying vehicles(GA 164—2005).In comparison with B-grade bulletproof steel plate made by one of the companies in Sweden,the weight of the developed B-grade bulletproof steel plate can be decreased by 8 %under the same shoot resistance condition.It will be meaningful for cash truck and anti-hijacking vehicle to realize light weight,energy conservation and emission reduction.展开更多
The current practice of rock/coal outburst monitoring, prevention and control was reviewed. The uncertainty of major factors contributing to the occurrence of such hazards and the complexicity of mining conditions sur...The current practice of rock/coal outburst monitoring, prevention and control was reviewed. The uncertainty of major factors contributing to the occurrence of such hazards and the complexicity of mining conditions surrounding the occurrence were analyzed. A strategic concept for rock/coal outburst prevention was introduced. The objective is to identify the bursting potential in an area, rather than predicting the bursting, by introducing a multi- dimension index model： potential-of-bursting （POB）, taking into consideration major contributing factors. In application, once the index has passed certain critical level indicating high risk, actions must be taken to reduce the bursting potential and to effectively prevent the hazard from occurring. A conceptual 2D model involving stress and methane pressure was described to demonstrate the methodology for determining the POB. However in practice, a POB model has to be established through experiments, field monitoring and calibration against case studies. To achieve this objective, coordinated research and international collaboration will be needed.展开更多
It has been developed and implemented for use antiradiation mask ＂ARR-I＂ for use in the uranium industry. The outer layer is treated with a special solution with anti-gas composition, which holds the gaseous radioac...It has been developed and implemented for use antiradiation mask ＂ARR-I＂ for use in the uranium industry. The outer layer is treated with a special solution with anti-gas composition, which holds the gaseous radioactive isotopes.展开更多
The nano-size metal oxide was prepared by the single-disperse technique on liquid phase, and formed sol dusters, its uniform film was covered on the surface of cashmere fibers by coating, and it had good oil repellenc...The nano-size metal oxide was prepared by the single-disperse technique on liquid phase, and formed sol dusters, its uniform film was covered on the surface of cashmere fibers by coating, and it had good oil repellency and water repellency. The results of IR（infrared） Spectrometer analysis revealed： The nano material combines through the strong bonds with the surface of cashmere fibers by the live groups. These analyses by SEM techniques showed that the nano material was distributed on the fiber surface even, and the nano material formed the strong peak of the regular crystal phase structure using the X-Ray Diffractometry （XRD） to analysis the fabric. The optimum techniques were selected by a series of experiments, coated cashmere fabric not only has preserved original properties of softness and comfort, but also has good properties of Bi-repellency function. Therefore, the technique will have potential appfication in engineers.展开更多
基金Supported by Fujian Administration of Education for Science Research (JB08232)the State Key Development Program for Basic Research of China(2006CB202200)
文摘The site drilling packer permeability test and TEM to the 2100 workface in Gucheng coalmine determined the two-zone height under sublevel strip mining.The conclusion considers that the lying strata deterioration law of the strip mining is similar to that of the sublevel mining.Thus, against that the actually measured data lacked, it is feasible to refer to the reservation of the waterproof coal pillar in the neighbor coalmine under sublevel situation.However, it is necessary to further launch the research on lying strata deterioration law under sublevel striping mining for the purpose of providing the right foundation for the layout of the workface not mined so far and the reservation of the waterproof coal pillar in the mining area.
基金Projects 50725931 supported by the National Science Fund for Distinguished Young Scholars50779050 and 50639100 by the National Natural Science Foundation of China
文摘We studied variations in the stress field around guide holes drilled during tunnel excavation to understand the mechanical mechanism by which these holes help prevent rockburst.The study used elasto-plastic analysis of a circular chamber under non-axisymmetrical loads.The results showed that the unloading of in-situ stresses, and the forming of a secondary stress field, leads to a severe change in the stress field around the guide holes.This causes the formation of an X-shaped area of plastic deformation, which prevents the rockburst.Adopting a sub-model finite element technique, we analyzed the factors that influence the distribution of the plastic area, such as the guide hole distribution and the in-situ stress state.The calculations showed that higher initial stresses result in greater adjustment to the stress field.When the stress concentration is greater the size of the plastic area surrounding the guide hole is larger.A multi-row distribution of the guide holes shaped like a quincunx can increase the interconnectivity of the plastic areas and allow the plastic area to extend from the tunnel wall deep into the surrounding rock.An optimized design was put forward based on the distribution of the plastic area around guide holes and the factors that influence it.
文摘With the mine exploitation depth getting deeper and deeper, the mine heat-harm turns into another natural disaster after the five disasters, which are the roof, the gas, the fire, the dust and the flood disaster. Compared with other researches on prevention and cure against the heat-harm, the research on prevention and cure against the heat-harm in constructing mine are less. Referring to the experience of prevention and cure against the heat-harm home and ＇abroad, analyzing the characteristic of cooling in the constructing mine, and based on the ground former freezing equipments and the modified mine temporary cooling equipments, the paper proposed four technical projects. By comparing with the four technical projects, the second project is preponderant both in technology and economy and can solve the heat-harm of the constructing mine, which is proved by the forecast and calculation. The project can be widely applied in de-temperature tasks of high temperature and heat-harm mines during the mine constructing period and in the exploiting preparing phase.
基金the National Natural Science Foundation of China(50375026)the Key Program of Science and Technology of the Ministry of Education of China(204183)the Program for New Century Excellent Talents in University of China(NCET-04-0971)
文摘According to the characteristic of clay aquiclude of overburden,the proper simulation materials and proportions of mixture for simulating the plastic clay aquiclude layers were developed,and the plastic similarity conditions were setup.Thus,the simili- tude and simulation method in whole stress-strain was progressed.Furthermore,the simulation condition and material proportions in water reaction property and crack closing property were also put forward.Based on systematical tests,the development and distri- bution of mined cracks in roof and subsurface aquiclude was found and the stability of aquiclude was analyzed at all.At last,the key section and key index of aquclude stability was advanced.It is found that the movement of clay aquiclude follows the movement of the underlying bedrock layers.The basic caving mechanism of the overburden roof strata was also presented.
文摘This paper studies the effect of ground stress, pore gas pressure and adsorbed methane on methane transport in coal seam. and researches into the applleability of Darey’s inw to methane transport. The additional expansion stress of coal induced by adsorbed methane is measured. The paper establishes the constitutive equation of methane transport, taking ground stress, pore gas pressure and Klinkenburg’s effects into consideration. The features of methane transport under the condition of given stress or strain have been analyzed.
文摘The light weight heat treated B-grade bulletproof steel was developed through composition design and optimization based on multiplex alloying,multiplex micro-alloying design ideas and complex phase structure strengthening theory.The puzzle how to avoid the quenching deformation problem of super high strength thin sheet was solved through heat treatment in a die with a set of cooling system.Such B-grade bulletproof steel plate has fine tempered lath martensite structure.The shooting and certification test results showed that the shoot resistance of B-grade bulletproof steel plate can meet the protection demand of Protection specification for cash carrying vehicles(GA 164—2005).In comparison with B-grade bulletproof steel plate made by one of the companies in Sweden,the weight of the developed B-grade bulletproof steel plate can be decreased by 8 %under the same shoot resistance condition.It will be meaningful for cash truck and anti-hijacking vehicle to realize light weight,energy conservation and emission reduction.
基金Supported by the National Natural Science Foundation of China（50534080） the Program for New Century Excellent Talents in University of China （NCET-05-0602）
文摘The current practice of rock/coal outburst monitoring, prevention and control was reviewed. The uncertainty of major factors contributing to the occurrence of such hazards and the complexicity of mining conditions surrounding the occurrence were analyzed. A strategic concept for rock/coal outburst prevention was introduced. The objective is to identify the bursting potential in an area, rather than predicting the bursting, by introducing a multi- dimension index model： potential-of-bursting （POB）, taking into consideration major contributing factors. In application, once the index has passed certain critical level indicating high risk, actions must be taken to reduce the bursting potential and to effectively prevent the hazard from occurring. A conceptual 2D model involving stress and methane pressure was described to demonstrate the methodology for determining the POB. However in practice, a POB model has to be established through experiments, field monitoring and calibration against case studies. To achieve this objective, coordinated research and international collaboration will be needed.
文摘It has been developed and implemented for use antiradiation mask ＂ARR-I＂ for use in the uranium industry. The outer layer is treated with a special solution with anti-gas composition, which holds the gaseous radioactive isotopes.
文摘The nano-size metal oxide was prepared by the single-disperse technique on liquid phase, and formed sol dusters, its uniform film was covered on the surface of cashmere fibers by coating, and it had good oil repellency and water repellency. The results of IR（infrared） Spectrometer analysis revealed： The nano material combines through the strong bonds with the surface of cashmere fibers by the live groups. These analyses by SEM techniques showed that the nano material was distributed on the fiber surface even, and the nano material formed the strong peak of the regular crystal phase structure using the X-Ray Diffractometry （XRD） to analysis the fabric. The optimum techniques were selected by a series of experiments, coated cashmere fabric not only has preserved original properties of softness and comfort, but also has good properties of Bi-repellency function. Therefore, the technique will have potential appfication in engineers.
