Zhou Guoqing

Closed-form solution of mid-potential between two parallel charged plates with more extensive application*

Efficient calculation of the electrostatic interactions including repulsive force between charged molecules in a biomolecule system or charged particles in a colloidal system is necessary for the molecular scale or particle scale mechanical analyses of these systems. The electrostatic repulsive force depends on the mid-plane potential between two charged particles. Previous analytical solutions of the mid-plane potential, including those based on simplified assumptions and modern mathematic methods, are reviewed. It is shown that none of these solutions applies to wide ranges of inter-particle distance from 0 to 10 and surface potential from 1 to 10. Three previous analytical solutions are chosen to develop a semi-analytical solution which is proven to have more extensive applications. Furthermore, an empirical closed-form expression of mid-plane potential is proposed based on plenty of numerical solutions. This empirical solution has extensive applications, as well as high computational efficiency.

Research on the model test system of shaft lining interacting with enclosure rock under deep and high water pressure

Based on the aquifer rock condition in west-northern coal mine China and the general mechanical and seepage differential equations, firstly, the similarity criterion related to interaction of water, surrounding rock and shaft lining were derived, then the shaft test device had been made according to the mechanical model of plain strain cylinder, showing especially in the aspect of structure and technology of gravity loading and pore pressure loading system. Thirdly, based on real tests and Comsol Multiphysics, numeral model test concerned coupling fluid and solid were carried out accordingly. Contrasting analysis among test, analytic calculation and FEM model would offer good reference for further model tests. The newly model tests device based on interaction of water, surrounding rock and lining are helpful to solve the problem of lining design for the strata of high pressure water.