Floor water inrush is one of the main types of coal mine water hazards.With the development of deep mining,the prediction and evaluation of floor water inrush is particularly significant.This paper proposes a variable...Floor water inrush is one of the main types of coal mine water hazards.With the development of deep mining,the prediction and evaluation of floor water inrush is particularly significant.This paper proposes a variable weight model,which combines a multi-factor interaction matrix(MFIM)and the technique for order performance by similarity to ideal solution(TOPSIS)to implement the risk assessment of floor water inrush in coal mines.Based on the MFIM,the interaction between seven evaluation indices,including the confined water pressure,water supply condition and aquifer water yield property,floor aquifuge thickness,fault water transmitting ability,fracture development degree,mining depth and thickness and their influence on floor water inrush were considered.After calculating the constant weights,the active degree evaluation was used to assign a variable weight to the indices.The values of the middle layer and final risk level were obtained by TOPSIS.The presented model was successfully applied in the 9901 working face in the Taoyang Mine and four additional coal mines and the results were highly consistent with the engineering situations.Compared with the existing nonlinear evaluation methods,the proposed model had advantages in terms of the weighting,principle explanation,and algorithm structure.展开更多
An ideal metal catalyst requires easy contact with reaction reagents, a large number of exposed active sites, and high stability against leaching or particle agglomeration. Anchoring a metal core inside a porous shell...An ideal metal catalyst requires easy contact with reaction reagents, a large number of exposed active sites, and high stability against leaching or particle agglomeration. Anchoring a metal core inside a porous shell, though scarcely reported, may combine these advantages owing to the integration of the conventional supported metal arrangement into a core@void@shell architecture. However, achieving this is extremely difficult owing to the weak core-shell affinity. Herein, we report, for the first time, an approach to overcome this challenge by increasing the core-shell interaction. In this regard, we synthesized a novel Au@void@periodic mesoporous organosilica （PMO） architecture in which a single Au core is firmly anchored inside the porous shell of the hollow PMO sphere. The non-covalent interactions between the poly（vinylpyrrolidone） （PVP） groups of functionalized Au and ethane moieties of PMO facilitate the movement of the Au core towards the porous shell during the selective alkaline etching of Au@SiO2@PMO. Shell-anchored Au cores are superior to the suspended cores in the conventional Au@void@PMO in terms of contact with reagents and exposure of active sites, and hence show higher catalytic efficiency for 4-nitrophenol reduction. The methodology demonstrated here provides a new insight for the fabrication of versatile multifunctional nanostructures with cores anchored inside hollow shells.展开更多
基金Projects(41877239,51379112,51422904,40902084,41772298)supported by the National Natural Science Foundation of ChinaProject(2019GSF111028)supported by the Key Technology Research and Development Program of Shandong Province,China+1 种基金Project(2018JC044)supported by the Fundamental Research Funds of Shandong University,ChinaProject(JQ201513)supported by the Natural Science Foundation of Shandong Province,China。
文摘Floor water inrush is one of the main types of coal mine water hazards.With the development of deep mining,the prediction and evaluation of floor water inrush is particularly significant.This paper proposes a variable weight model,which combines a multi-factor interaction matrix(MFIM)and the technique for order performance by similarity to ideal solution(TOPSIS)to implement the risk assessment of floor water inrush in coal mines.Based on the MFIM,the interaction between seven evaluation indices,including the confined water pressure,water supply condition and aquifer water yield property,floor aquifuge thickness,fault water transmitting ability,fracture development degree,mining depth and thickness and their influence on floor water inrush were considered.After calculating the constant weights,the active degree evaluation was used to assign a variable weight to the indices.The values of the middle layer and final risk level were obtained by TOPSIS.The presented model was successfully applied in the 9901 working face in the Taoyang Mine and four additional coal mines and the results were highly consistent with the engineering situations.Compared with the existing nonlinear evaluation methods,the proposed model had advantages in terms of the weighting,principle explanation,and algorithm structure.
基金The authors gratefully acknowledge financial support from the National Natural Science Foundation of China （Nos. 21303229, 21173269, 91127040）, Beijing Natural Science Foundation （No. 2152025）, the Science Foundation of China University of Petroleum, Beijing （No. 2462013YJRC018）, Ministry of Science and Technology of China （No. 2011BAK15B05）, and Specialized Research Fund for the Doctoral Program of Higher Education （No. 20130007110003）.
文摘An ideal metal catalyst requires easy contact with reaction reagents, a large number of exposed active sites, and high stability against leaching or particle agglomeration. Anchoring a metal core inside a porous shell, though scarcely reported, may combine these advantages owing to the integration of the conventional supported metal arrangement into a core@void@shell architecture. However, achieving this is extremely difficult owing to the weak core-shell affinity. Herein, we report, for the first time, an approach to overcome this challenge by increasing the core-shell interaction. In this regard, we synthesized a novel Au@void@periodic mesoporous organosilica （PMO） architecture in which a single Au core is firmly anchored inside the porous shell of the hollow PMO sphere. The non-covalent interactions between the poly（vinylpyrrolidone） （PVP） groups of functionalized Au and ethane moieties of PMO facilitate the movement of the Au core towards the porous shell during the selective alkaline etching of Au@SiO2@PMO. Shell-anchored Au cores are superior to the suspended cores in the conventional Au@void@PMO in terms of contact with reagents and exposure of active sites, and hence show higher catalytic efficiency for 4-nitrophenol reduction. The methodology demonstrated here provides a new insight for the fabrication of versatile multifunctional nanostructures with cores anchored inside hollow shells.
