次春

回归年是平太阳两次通过平春分点的时间间隔。

The tropical year is the interval between two transits of the mean Sun through the mean Equinox .

夏季次之；春、秋两季较弱，最小在春季。

Wind stree in summer comes next and those in spring and autumn are quite weak , with minimum wind stree in spring .

华北地区夏季存在3年左右的主周期及6年左右的次周期，春、秋、冬三季都存在3年左右的主周期。

Summer rainfall of North China exists periodic variation of quasi-three years and six years , and . spring , autumn and winter also exist periodic variation of quasi-three years .

长效氮肥一次基施在春玉米上的试验效果

Trial effect of once basal dressing of slow release nitrogen fertilizer on spring corn

摇蚊幼虫集中羽化的时间有两次，主要为春末夏初的4-5月和秋末冬初的11-12月。

The centralized adult emergence of Chironomid larvae appears twice a year and normally appears in April to May and November to December .