This paper set forth the changeability of quick-return motion and quick-return characteristics in the different extreme positions on double crank mechanism, and expressed them in the form of the line graphics ψ3～θ.

The mechanism offset double crank slider not only has the characteristic of super quick-return (k>3),but also has variety time ratio.

The characteristic of quick-return of radial double crank slider mechanism was analyzed,the result proved that this mechanism not only has the characteristic of super quick-return but also has the characteristic of variety quick-return.

In the paper, the graphic method and the analytic method are applied to analyze the fast back kinematic characteristic of double crank mechanism, in term of which the formula of fast back kinematic characteristic coefficient of double crank mechanism is deduced.

The significant results are that the time ratio of quickreturn mechanism is increased and its feasible range is enlarged.

Effects of different contents dithicthreitol on lipid peroxidantion in heart, liver and kindney of mouse after acute exercise;

Experiment study on effect of acute exercise on serum oxygen free radicals metabolism levels;

Aims The present study is to explore the implications of the skeletal muscles mitochondrial ROS generation and UCP3 expression during and after acute exercise.