This paper focuses on the stability studies of a AC and DC hybrid system feeding into a week AC system.

The stability of Shandong power grid as preliminary receiving end is simulated and analyzed.

The nonlinear FEM models of concrete-filled square tubular column with internal diaphragms to composite steel-concrete beams with reduced beam section connections involving geometric ally large deformation and materials nonlinear is presented.

With the actual three-dimension element,the nonlinear finite element analytic models were established for bolt-weld joints between square concrete-filled tubular(CFT) column and reduced beam section with inner separates,considering geometric large deformation,materials nonlinear and contact nonlinear.

The equivalent form of reduced beam section which was fit to SAP2000 analysis design software was presented.

Based on spherical shell structure and graded finite potential well model,the interface effects on the ground state level shifts of bound states in a weakly-confined spherical semiconductor quantum dot heterostructures are analyzed and calculated.

Aiming at the mode of weakening in the end of beam and the mode of strengthening in the end of beam,this article put foreword the correspond detailing measures and appliance characteristics,therefore the arti.