The results show that the residual strength of the three kinds of materials declines with increasing the thermal shock temperature,and the critical temperatures for sharply decline of residual strength are 410,370 and 330.

The influence of increasing sodium silicate addition and adding organic ester on residual strength and final strength after 24 h of sodium silicate sand was analyzed with orthogonal experiments.

The influences of furnace-cooling and air-cooling on residual strength values of sodium silicate sand after heating at high temperature was compared by experiment.

Tensile and retained strength of microwave hardened waterglass modified with 1~# agent were investigated.

The fundamental ingredients of PEO modified sodium silicate binder are determined, and the bonding strength in room temperature and retained strength in high temperature of ester cured sand and CO2 hardening sand are tested.

The results show that collapsibility agent of 24 hours with stronger strength as well as in (800℃) with weaker retained strength is more effective.

According to a relation between completeness of Abstract interpretations and strong preservation of Abstract model checking,the problem of minimally refining Abstract model in order to make it strongly preserving CTL can be formulated as a minimal Abstract domain refinement in Abstraction interpretation in order to get completeness,and this refined complete Abstract domain always exists.