<正> Studied the harmonic control of the 6 kV power grid in a coal mine substation.Taking harmonic suppression and reactive power compensation into account, and
<正> A nonlinear dynamics model and a mathematical expression were set up to investigatethe mechanism and conditions of vibration creep acceleration.The model s
<正> The experiment of gas and coal dust explosion propagation in a single lanewaywas carried out in a large experimental roadway that is nearly the same with a
<正> The curves of crack relative length lib and crack growth time t of granite were gained under compressive stresses state according to subcritical crack grow
<正> Steeply dipping seam group,which has complex occurrence conditions,be- longs to the steeply dipping seam.The research on the strata movement around the coa