In this paper the onedimonsional Stefantype model for the heat effect of highirradiance laser on biotissues and the inverse problem identification are adopted to obtain a relational expression for calculating the ablation depth in laserirradiated tissues, in which the complex nature of actual situationthe multidimensional problemis taken into account.

The damage morphology, and threshold fluence as a function of pulse duration and the dependence of ablation depths on the pulse fluences are measured.

The relation between damage threshold,ablation depth and laser pulse duration,wavelength,energy fluence is studied with the model.

In combination with corrosion analysis, especially with the pit corrosion analysis, a model for calculating collecting line pit corrosion depth and a model for statistically predicting the leak off in the collecting line caused by pit corrosion are established on the basis of corrosion investigation.

The length of the bubble cloud equals to the standoff distance plus the drilling depth.

8 times that of copper,the corrosion depth is reduced more 50%.

Applying this model to predict one of Sichuan Gas Field' s gas pipeline's corrosion rate and corrosion depth, the counting result indicated .

Statistics analysis shows that,the maximal corrosion depth on steel pressure vessels and pipelines is subject to I-type max value distribution,and the corrosion fatigue life belongs to I-type minimal value distribution.

The relation of energ/etching depth is obtained.

The etching depth of the circles showed a decreasing trend in the same processing conditions.