Because the electrical equations in electrostatic precipitator are analogous to the equations used to describe fluid flow,the downwind scheme in computational fluid dynamics is introduced to solve the current continuity equation in the case of positive corona,and the relevant upwind scheme is applied in the case of negative corona.

It is proved that the ad joint semigroup of a positive implicative BCKalgebra with condition(s) is a lower semilattice.

Suggestions on implementing price floor regulation in mobile services in China;