Change Characteristics of the Maximum Depth of Frozen Earth at Tongliao National Basic Meteorological Observation Station in Recent 50 Years and Their Correlation Analysis with Ground Temperature and Air Temperature

Change Characteristics of the Maximum Depth of Frozen Earth at Tongliao National Basic Meteorological Observation Station in Recent 50 Years and Their Correlation Analysis with Ground Temperature and Air Temperature Animal Husbandry and Feed Science . 2012, (9): 11 -11 . DOI: 10.12160/j.issn.1672-5190.2012.09.005