In this paper,graph coloring problem was combined with the number of bad edges and transformed into a problem of searching for the long.

Some aspects for survey of expressway depending on the characteristics of several slope failure;

Based upon the fundamental features, time-space regularities of slope failures of the Bailuyuan loessial plateau, at Xi′an suburb, the author analyses their occurring conditions and main affecting factors, and accordingly makes a proposal of key measures to prevent and cotrol future slopt slides permanently.

By applying the classical accelerate damage boundary theory in package dynamics and the displacement damage boundary which had been put forward by the author recently, the relation is studied in linear system between the critical dropping high of the products and the properties of the cushioning material including the stiffness and the deformation limitation.