change analysis of dynamically change

change gear change wheel

change-object or change-constraint method

quantity change and quality change

structural change model with unknown change point

active permafrost

Alpine permafrost

arctic permafrost region

artificial permafrost table

calculation of temperature field of permafrost

continuous permafrost zone

culvert in permafrost region

DEGENERATIVE PERMAFROST

degradation of permafrost frozen soil

discontinuous permafrost zone

dry permafrost

Embankment in Permafrost Region

fossil permafrost

Harmful permafrost phenomenon