Based on the fact of the toxic gas diffusion from gas explosion, Gaussian puff model was improved, and the formula in accord with the diffusion rule of toxic gas from gas explosion in mines was set up.

In this article the studies on moisture diffusion process, hygroscopic stresses and moisture-induced vapor pressure are reviewed, with the emphasis on the theoretical analysis, parameter characterization and its experimental measurement and validation, as well as the finite element simulation.

This paper analyzes rules of moisture diffusion in PBGA and PQFP packages and influence of temperature during dry baking using finite element analysis models.

The feasibility to simulate the accidental leaked heavy gas dispersion in atmosphere by salt water experimental method is analyzed according to the similarity theory.

The forward finite difference and Newton iterance are used in the light of box model and other heavy gas dispersion models, such as IIT Heavy Gas Models and virtual point source model, to solve the differential equations of controlling heavy gas cl.

A Virtue Instrument(Ⅵ)on the heavy gas dispersion was designed and constructed based on the forming causes, the physical properties and the dispersion processes of varies heavy gases,by utilizing the developed data bases,or the numeric controllers written on theⅥinterface manually for the characteristic parameters.