Minimal Periodic Solutions of SuperquadraticFirst Order Convex Hamiltonian Systems

This paper generalizes all known results on Rabinowitz's minimal periodic solution conjecture under the assumption that Hamiltonian function is C2 strictly convex.     

STATE VARIABLE METHOD FOR DYNAMIC SIMULATION OF HVDC SYSTEMS

A flexible mathematical model used for dynamic simulation studies of HVDC systems which is based on the stale variable method is presented, and the correspongding computer program has been implemented. Generality, easy to use, and suitable to run on microcomputers are the main features of the model and the computer program. Therefore the model is easy to be extended for application. An example is given in the paper to verily the coneclness of the model and the program.     

THREE CRITICAL POINTS THEOREM AND ITS APPLICATIONS

In this paper, by use of the pseudo-gradient vector field, the three critical points theorem in [2] is extended to the C1 function in the Ba-nach space, and therefore the three critical, points theorem in [5] is strengthened and the existence of the saddle point of the C2 function is discussed.     

THE MATHEMATICAL MODEL OF CARBURIZED MASS-TRANSFER AND ITS MEANINGS

This paper deals with the kinetics of carbon atoms transfer from gas phase to solid phase in gas carburizing. According to the kinetic equations of the chemical reactions on the solid surface, it is deduced that the carbon transfer quantity from gas phase to solid phase is in direct proportion to the difference of carbon activiries between gas phase and solid phase. Based on what is mentioned above, we set up the kinetic equation of carbon transfer from gas phase to solid phase, discussed the factors which affected the carbon transfer. It was known then that increasing the contents of carbon monoxide and hydrogen in gas phase could qu'icken the carbon transfer. On the other hand, proper oxidants, especially proper water, could quicken the carbon transfer.     

A CALCULATION OF THE ECCENTRICALLY LOADED BRICKWORK WITH BIAXIAL BENDING IN TERMS OF ULTIMATE STRENGTH DESIGN METHOD

This paper suggests a calculation formula for eccentrically loaded brickwork or column with biaxial bending in terms of ultimate strength design method. The coefficients of the formula, are compiled as design charts so that the formula can be directly used for design of this kind of structural members.     

THE EXISTENCE OF APPROXIMATE EXTREME POIKTS OF CONSTRAINED OPTIMIZATION

According to the theories o?Riemannian manifolds and variational principles, two theorems about the existence of approximate extreme point of constrained optimization are given in this paper.     

LABORATORY INVESTIGATION OF ESSENTIAL CHARACTERISTICS PARAMETERS FOR THE INDUCED-NOZZLE DEVICE

The standoff of a submerged jet is smaller than a non-submerged jet in general. In order to increase the standoff of a submerged jet, the induced-nozzle device is presented with its inducing mechanism analysed in this paper. Under the various inducing medium, the effect of the ratio d2/d1 upon the device's properties is measured. Some reasonable parameters are given. When d2/d1=2.0, approximate straight region of the curve of the jet center line stagnation pressure varying with the standoff is L/d1= l0~12 for inducing air. The induced-nozzle device is compared with the conventional nozzle for shotting some samples. Several applied possibilities of the device are discussed.     

Optimal Design of Plane Cascades Based on Wavelet Theory

Based on the optimal control theory and Lagrange interpolation an optimal design model of plane cascades of 3D blade in an arbitrary surface of revolution is established. Using wavelet theory to solve the model, and lots of numerical results are obtained. The results show that the wavelet method is more effective than the conventional methods.