日温变化 meaning in English

daily temperature fluctuation

The system is able to efficiently increase temperature and meet crop requirement of temperature for yield . in researching and designing solar energy conserving system in soil for active greenhouse , it adopts instrument of rhlog , tests temperature of six layers to soil temperature , and draws various curve of temperature . it shows the system can efficiency increase soil temperature and reduces change range of temperature in greenhouse in wintertime
在研究和设计主动式温室太阳能地下蓄热系统中，采用温度自记仪器，测试了室温及土壤中六个不同深度的温度数据，绘制了相关温度变化曲线，该曲线表明了主动式温室太阳能地下蓄热系统能有效提高冬季温室土壤的温度，并且减小了日温变化幅度。