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The fault water damage accounts for most of the coal mine floor water inrush accidents in China, and the pillar design of fault waterproof coal(rock) is the main means to prevent fault water damage, which is related to the safety and efficient production of coal mine. The reasonable width of fault waterproof coal (rock) column can not only prevent the underground water from pouring into the mine through the fault, but also serve the reasonable and safe mining of coal resources. The design of fault waterproof coal (rock) column width involves many factors and is one of the focuses of many scholars and engineers. A variety of research methods have been applied at present, including theoretical calculation, multiple regression analysis, BP and RBF, similarity simulation, numerical simulation for the coal (rock) column design under different fault conditions have been specifically studied. On this basis, the research status of fault coal (rock) pillar is summarized, the existing problems are pointed out, and the future research technology and methods are prospected.

Mg80Ni16−xAlxY4 (x = 2, 4, 8) alloys were prepared by induction levitation melting, and the effect of substitution of Al for Ni on the microstructure and hydrogen storage properties was studied in the present work. The results illustrated that the solidification path, phase constitution, and grain size were significantly altered by Al addition. Appropriate Al addition improved abundance and grain refinement of the Mg, Mg2Ni, and Mg15NiY ternary eutectic. But as Al further increased, Mg solidified independently rather than in the formation of the ternary eutectic. More Al favored the formation of Al3Ni2Y but suppressed Mg2Ni and YMgNi4. Although the hydrogen absorption activation and the kinetic property deteriorated, the thermodynamic stability of hydrides was enhanced by adding Al. Hydrogen absorption ability under low pressure was improved, and the Mg80Ni8Al8Y4 alloy could absorb nearly 3.5 wt% hydrogen under 1 bar hydrogen at 250 °C. [ABSTRACT FROM AUTHOR]

The requirements regarding the weight and capacity reduction of neutron shielding materials have become an urgent issue for advanced nuclear facilities and plants. An epoxy-based neutron shielding material with high-temperature stability and good neutron irradiation resistance was designed in this paper to solve the above issue. Aminophenol trifunctional epoxy resin (AFG-90H) was compounded with samarium oxide (Sm2O3) by means of an ultrasonic-assisted method and the compatibility of Sm2O3 with the AFG-90H matrix was improved by 3-aminopropyltriethoxysilane (APTES) surface modification. Fabricated Sm2O3-APTES/AFG-90H composites exhibited improved thermal stability, glass transition temperature and Young's modulus with increased Sm2O3-APTES content. Neutronics calculation results show that the neutron permeability of 2 mm-thick 30 wt% Sm2O3-APTES/AFG-90H was 98.9% higher than that of the AFG-90H matrix under the irradiation of the thermal neutron source. The results show that the proper addition range of Sm2O3-APTES is between 20% and 25%. The Sm2O3-APTES/AFG-90H composite is a promising neutron shielding material for advanced nuclear system. [ABSTRACT FROM AUTHOR]