According to the characteristics of comprehensive mechanized heading face, established the mathematical model of single-phase air flow with κ-ε two equations model, and have established κ-ε-θ-κp mathematic model...According to the characteristics of comprehensive mechanized heading face, established the mathematical model of single-phase air flow with κ-ε two equations model, and have established κ-ε-θ-κp mathematic model to solve two-phase flow of gas and particles in dust space with eulerian-eulerian method and eulerian-lagrangian method. Numerical solution of gas-particle two-phase flow was put forward based on collocated grid SIMPLE algorithm. Moreover, numerical simulation of dust concentration in fully mechanized caving face was carded out by using Fluent software. Finally, when in forced-exhaust ventilation circumstance, drawer type fan drum have less dust absorption, and most of dust spread to the other site; the dust concentration is inversely proportional to the distance from tunneling head, and the dust concentration has already diffused to decrease below 102 mg/m3 at the position ofx=12 m. Dust are more focused on relative side（in the range about y from 0 to 2 meter） of roadway space of press-ventilated fan drum, especially between tunneling place and drawer type fan drum; the roadway with road header have a higher dust concentration. These conclusions provide reliable theory basis for the dust prevention in comprehensive mechanized heading face.展开更多
A novel room-temperature ionic liquid (RTIL),1-allyl,3-methylimidazolium chloride (［AMIM］Cl),was synthesized,ch aracterized and used for dissolving cellulose.The solubility of cellulose in ［ AMIM］Cl was better tha...A novel room-temperature ionic liquid (RTIL),1-allyl,3-methylimidazolium chloride (［AMIM］Cl),was synthesized,ch aracterized and used for dissolving cellulose.The solubility of cellulose in ［ AMIM］Cl was better than in 1-butyl,3-methylimidazolium (［BMIM］Cl).The pris tine cellulose and two cellulose samples regenerated from ［AMIM］Cl and ［BMIM ］Cl solutions were compared by FTIR,WAXD and TGA measurements.Results show t hat these two RTILs are non-derivatizing solvents for cellulose.After regenera tion from RTIL solutions,the crystalline form of cellulose films is completely transformed from cellulose Ⅰ to cellulose Ⅱ.Compared to pristine cellulose,t he regenerated cellulose exhibits a lower onset temperature of thermal decomposi tion,with a higher char yield.展开更多
基金Supported by the National Natural Science Foundation of China （51074100） the National Natural Science Foundation of Shan dong province （ZR2OIOEM016）
文摘According to the characteristics of comprehensive mechanized heading face, established the mathematical model of single-phase air flow with κ-ε two equations model, and have established κ-ε-θ-κp mathematic model to solve two-phase flow of gas and particles in dust space with eulerian-eulerian method and eulerian-lagrangian method. Numerical solution of gas-particle two-phase flow was put forward based on collocated grid SIMPLE algorithm. Moreover, numerical simulation of dust concentration in fully mechanized caving face was carded out by using Fluent software. Finally, when in forced-exhaust ventilation circumstance, drawer type fan drum have less dust absorption, and most of dust spread to the other site; the dust concentration is inversely proportional to the distance from tunneling head, and the dust concentration has already diffused to decrease below 102 mg/m3 at the position ofx=12 m. Dust are more focused on relative side（in the range about y from 0 to 2 meter） of roadway space of press-ventilated fan drum, especially between tunneling place and drawer type fan drum; the roadway with road header have a higher dust concentration. These conclusions provide reliable theory basis for the dust prevention in comprehensive mechanized heading face.
文摘A novel room-temperature ionic liquid (RTIL),1-allyl,3-methylimidazolium chloride (［AMIM］Cl),was synthesized,ch aracterized and used for dissolving cellulose.The solubility of cellulose in ［ AMIM］Cl was better than in 1-butyl,3-methylimidazolium (［BMIM］Cl).The pris tine cellulose and two cellulose samples regenerated from ［AMIM］Cl and ［BMIM ］Cl solutions were compared by FTIR,WAXD and TGA measurements.Results show t hat these two RTILs are non-derivatizing solvents for cellulose.After regenera tion from RTIL solutions,the crystalline form of cellulose films is completely transformed from cellulose Ⅰ to cellulose Ⅱ.Compared to pristine cellulose,t he regenerated cellulose exhibits a lower onset temperature of thermal decomposi tion,with a higher char yield.
