The net cross-sectional area is 10.71 m2. Typical deep mining problems such as high pressure, high temperature, and severe deterioration of the surrounding rock have emerged in the right working face. As shown in Fig. 3, at the Pinggang Coal Mine, multiple attempts at using pillarless ...
life owing to their large interstitial channels and robust three-dimensional (3D) frameworks6,7,8,9, typically involving a NASICON-type ATi2(PO4)3(A = Na, K, et al.) anode6,7. However, their working potential (~ 2.2 V vs. Na+/Na) is too positive to reach a high ener...
The position (b) of the rhombic shape section 3 is shrunk in width into a peak shape, the cross sectional shape is smoothly shrunk in the width direction in sequence toward the position (b) shrunk in width, thus press molding can be easily applied. When the rhombic shape sections 3 are...
In summary, in the engineering application of retaining an 8 m coal pillar at the right first working face, the area was in a reduced stress zone, with the peak support pressure far from the roadway. The main deformation of the roadway occurred within the stress-affected zone, with the ove...
where: A is the initial undamaged cross-sectional area, At is the total cross-sectional area of the damaged part of the coal body, A1 is the cross-sectional area of the damaged part by stress, A2 is the cross-sectional area of the damaged part by water. Separate consideration of the ...
(c) Cross-sectional TEM images that confirm the presence of a nanoscale thin layer of P(VDF-TrFE) on both top part and side walls of the micropillar. (d) FT-IR spectra and (e) XRD analysis of the P(VDF-TrFE) core-shell micropillars. Full size image Fourier transform infrared (FTIR...
where ρ is the electrical resistivity of a single coal pillar specimen (Ω·m); R is the electrical resistance of a single coal pillar specimen (Ω); S is the effective cross-sectional area of a single coal pillar specimen (m2); H is the height of a single coal pillar specimen (m)...