In this paper, the authors introduced two methods of calculating the surge pressure for check valve,one is characteristics method,the other is performance curve method.

The volume efficiencies and pressure traces in intake and exhaust manifolds of a ten cylinder natural aspirated diesel engine, and the turbine entry and compressor exit pressures of a six cylinder turbocharged diesel engine were calculated by using characteristics method (CM) and finite volume method (FVM) individually.

The theoretical analyses and experimental results show that when characteristics method is used to calculate system of pipes with different diameters and the changes in momentum is taken into consideration,transient procedure in the system of hydraulic pipe can be described accurately.

An approach to the choice of characteristic curve during the process of reservoir inversion by the process of reservoir inversion of Pinghu Field;

The sufficient and necessary conditions of the generalized Liénard system for intersection of positive semiorbits with characteristic curve;

The conditions of the generalized Liénard system for intersection of positive semiorbits with characteristic curve;

Flier plate role research with difference method in characteristic line;

Based on the reflective theory of characteristic line,a model of shock waves formed by repeatedly reflected pressure waves between piston and fixed wall was established.

Based on the logarithmic spiral failure surface and combined with the characteristic line throry,a new computational method is proposed and procedure is prepared.