A water-resistant key strata model of a goaf floor prior to main roof weighting was developed explore the relationship between water inrush from and weighting. The stress distribution, broken characteristics, risk area for were analysed using elastic thin plate theory. formula maximum pressure tolerated by deduced. effects caved load goaf, size weighting, advancing distance workface or step, thickness on breaking instability analysed. results indicate that can be predicted prevented...

We report high-power efficient green light generation by frequency doubling from a periodically poled MgO doped LiNbO(3) ridge waveguide. The waveguide is fabricated the annealed proton-exchanging and precise diamond blade dicing techniques. structure exhibits surface roughness of only 3.7 nm, near-90° vertical sidewall. total insertion loss an 8.5 µm wide 1.4 cm long uncoated 3.0 dB under direct fiber coupling. 466 mW continuous-wave with optical-to-optical conversion efficiency 69.7%...

The effect of controlling strata movement in solid filling mining depends on the rate goaf. However, mechanical property overburden backfill stope and designed size workface should also be considered. In this study, we established a main roof model with loads accordance theory key to investigate stability dense mining. We analyzed stress distribution law based elastic thin plate theory. results show that position long side midpoint failed more easily because tensile yield, indicating is area...

Efficient cw 532 nm green-light generation is demonstrated using a periodically poled MgO:LiNbO3 ridge waveguide prepared by process that combines annealed proton exchange and precise dicing. Performance of waveguides with different widths has been investigated. The 6-μm-wide, 1.6-cm-long uncoated achieved green output power 127 mW under coupled fundamental light 250 mW. highest conversion efficiency 53%.

We propose a thermal rectification structure composed of InSb and graphene-coated 3C-SiC separated by nanoscale vacuum gap. To obtain an obvious effect, the permittivities these materials are all considered to be temperature-dependent. Numerical calculations based on fluctuation electrodynamics reveal that introduction graphene into enhances significantly near-field radiative heat flux efficiency owing strong coupling surface plasmon-polaritons between graphene. In general, above 60% can...

Secondary development of FLAC 3D software was carried out based on FISH language, and a fluid‐solid coupling numerical calculation model established for an inclined seam mining above confined aquifer in Taoyuan Coal Mine. A simulation study implemented the failure depth coal floor, conducting height water, position workface floor with easy water inrush during advancement workface. Results indicated that, seam’s workface, obvious equivalent stress concentration areas existed strata, largest...

Abstract The influence of the compounding route polypropylene (PP)/ethylene–propylene–diene terpolymer (EPDM)/nano‐CaCO 3 composites on their properties, including mechanical dispersion degree nano‐CaCO , and morphology EPDM, was studied. results showed that toughness EPDM particles were markedly influenced by route, whereas in matrix little route. impact strength prepared one about 60 kJ/m 2 with 20 wt % . indicated a sandbag embedded could effectively improve composites. A composed...

This paper deals with the theoretical aspects combined stress analysis over floor strata of coal seam and calculation model for on floor. Basically, this research presents relevant results obtained rock burst prevention in roadway driven along next goaf exploitation thick large obliquity deep well tendency. The control mechanism is revealed present work. That is, danger can be removed by changing environment energy accumulation reducing impact from strong dynamic pressure. result profitable...

The Casimir force between two inhomogeneous metal-dielectric composite slabs with spatial dispersion is investigated theoretically. equivalent permittivity and permeability of the nonlocal metallic nanosphere originally derived based on full-wave Mie theory. We then adopt effective medium models to study calculate Casimir-Lifshitz Due excitation longitudinal modes, attractive materials much weaker than that local composites, numerical results show relative errors calculations can be order...