Papers by Author: Miao Yu

Abstract: To investigate the mechanism on Capparis spionosa L polysaccharide(CSPS) inducing apoptosis in HepG2 human hepatoma cell. MTT was ddopted to determine if CSPS had cytotoxic effect on HepG2. Morphology of HepG2 changed with dosages of CSPS was detected by laser confocal scanning microscope. Flow cytometry(FCM) was used to detect the apoptosis by PI labeling method. Calcium, mitochondrial membrane potential, Bcl-2/Bax of HepG2 cells were detected by laser confocal scanning microscope. The result of MTT showed that CSPS could inhibit the growth of HepG2 significantly. HepG2 cells were shrinkage, fragmentation, appearance of apoptotic bodies by laser confocal scanning microscope. HepG2 cell apoptosis rate was increased gradually with dosage by FCM. Calcium concentration, mitochondrial membrane potential, Bcl-2 protein of HepG2 were decreased, Bax protein content of HepG2 was increased by laser confocal scanning microscope. CSPS induced HepG2 apoptosis by controlling Bax/Bcl-2 in Ca²⁺ path.

Abstract: This paper puts forward a multi-Agent alliance control model that is made up of the series robot Agent, the parallel moving platform Agent and the polishing tool system Agent and so on by organically introducing the MAS (Multi-Agent System) theory into the polishing. Through the introduction of point-curve constraint, the dynamics equation of the constraint multi-body for the polishing system is established in order to accurately program the moving track of the robots. Meanwhile, the control parameters during the polishing can be optimized and the foundation can be afforded for carrying out the collocation of the optimal parameters with the series-parallel coordinates polishing and programming the optimal path on the free-form surface.

Abstract: In order to solve the confliction among the working space, precision and stiffness on the free-form surface, this paper puts forward a Multi-Agent alliance control model that is made up of the series robot Agent, the parallel moving platform Agent and the polishing tool system Agent and so on by organically introducing the MAS (Multi-Agent System) theory into the polishing. Through the introduction of virtual point-curve constraint, the dynamics of the constraint multi-body equation for the polishing system is established in order to accurately program the moving track of the robots. Meanwhile, the control parameters and the optimal path during the polishing can be optimized.

Abstract: This paper develops a novel five DOF hybrid polishing kinematics machine tool in order to obtain more stable machining result in the elastic polishing on the free-form surfaces. Because the machine tool is a complex multi-body system that comprises many close-loop structures, jointing clearance becomes the important influence factor to its moving stability. The unified rigid multi-body and flexible multi-body dynamics equation of for the parallel mechanism of hybrid polishing kinematics machine tool is respectively built, which considers the influence of joint with clearance and applies the kinematics model of Newton second state. The result of analysis shows that the moving stability of the hybrid polishing kinematics machine tool is reduced due to the existing jointing clearance. However, the interior flexibility of the mechanism can reduce the shock effect of collision in the part of motion pair. It can improve the working stability of mechanism.

Abstract: The hybrid polishing kinematics machine tool (HPKMT) which is made up of “3 axes parallel + 2 axes series” is developed with the specially designed elastic polishing tool system for the polishing operation on the free-form surfaces by using the characteristic of the elastic polishing adequately by the authors. In order to control the HPKMT effectively, its characteristic of the kinematics and dynamics need be known deeply. Moreover, the problem of inverse dynamics is the theory foundation to apply dynamic control of the HPKMT. The analysis of the inverse of mechanism is the important part in the research of dynamics. On the basis of the differential equations of flexible multi-body dynamics, this paper discusses on the condition of knowing the trace, posture and velocity for the end of bodies how to solve the constraint force and constraint moment of each joint on the 3- PTT parallel mechanism and two-joint series mechanism.

Abstract: The virtual axis hybrid polishing machine tool (VAHMPT) is the novel equipment developed by the authors that is aimed at the precision machining on the free-form curved surfaces. This paper establishes the dynamic equations of the spatial rigid-flexible coupling multibody systems considering the coupling for the rigid movement of the whole VAHMPT with the elastic deformation of each leg by means of the theory of dynamics of flexible multibodysystems. Meanwhile the dynamic characteristics of the hybrid machine tool is studied in detail by the dynamics simulation analysis. The dynamic simulation of the machine shows that the elastic deformation of each leg is very small during the movement of the machine and the influence of the flexibility of each leg on the trace of moving platform is not obvious due to the characteristics of joints. The dynamic characteristics of the VAHPMT is verified combining with the experiments. It is shown that the experiments result is almost accorded with the simulation analysis. The satisfied polishing effect on the curved surfaces can be obtained and the demand of the polishing can be achieved by the VAHPMT.