关键词: 妊娠, 妊娠

Abstract: This paper analyzes the distribution features of changes of the mean maximum and minimum air temperatures with such methods as linear regression and MK mutation, etc., based on data sets of daily values in ground meteorological data of Liangping, Chongqing (1981-2010). The results show that the annual mean maximum air temperature, annual mean minimum air temperature and annual mean air temperature in Liangping present a trend of linear increase, and all annual mean maximum air temperatures in four seasons show a tendency of increase at different degrees; the increasing tendency of the mean minimum air temperature is: summer＞spring＞autumn＞winter. 1998 is the initial year of mutation for the annual mean maximum air temperature increase, the mutation time of the mean maximum air temperature in four seasons is basically consistent, and the latest mutation appeared at the end of the 20th century and the beginning of the 21st century. Remarkable increase of the annual mean air temperature has the biggest positive influence on the mean maximum and minimum air temperatures in the corresponding period. Based on this, the paper provides theoretical basis and reference for development and utilization of agroclimatic resources in Liangping.