反常积分敛散性的一个新判别法

关于反常积分的敛散性判定问题的判别方法比较多,并且大部分都源于比较判别法,即要事先挑选出一个已知其敛散性的反常积分作为比较对象。然而,寻找到这样合适的比较对象却是很困难的。本文通过分析被积函数的自身性态,给出了关于反常积分敛散性的一种新的判别方法,并通过实例说明了其应用以及优越性。

无人机飞防对棉花生长调控效果研究

通过设置3WQF125-16型智能悬浮植保机的飞行高度、飞行速度研究了不同作业参数喷施缩节胺对棉花株高、果枝节间的调控效果。试验结果表明:当无人机飞行高度为1.5 m、速度为4 m·s-1时喷施缩节胺,棉花株高、果节增长值显著低于清水对照,对调控棉花生长效果最好,且优于喷雾器喷施效果,对塑造棉花合理株型提供了有益探索。

RELATIONSHIP BRIMFUL OF OPPORTUNITIES The resilience and durability of relations over the past 30 years provide a strong foundation on which to build a China-ASEAN community with a shared future

Since the establishment of China-ASEAN dialogue relations in 1991,the two sides have been deepening their cooperation in an all-round manner,yielding fruitful results in various fields.A review of the 30 years unfolds an extraordinary and exciting journey defined by tremendous progress.

CHINAASEAN RELATIONS: THIRTY YEARS ON AND BEYOND

The new year dawns amidst unprecedented changes in a century,including the COVID-19 pandemic in particular.It will be a milestone year for China and ASEAN,as it ushers in the 30th anniversary of China-ASEAN dialogue relations.A review of the 30 years unfolds an extraordinary journey defined by tremendous progress.In 1991,China and ASEAN initiated the dialogue process marked by the attendance of the then Foreign Minister Qian Qichen at the Opening Ceremony of the 24th ASEAN Foreign Ministers’Meeting.In 2003,China acceded to the Treaty of Amity and Cooperation in Southeast Asia,ASEAN’s first dialogue partner to do so,and established China-ASEAN strategic partnership,which was again a trailblazing endeavor.

RELATIONSHIP BRIMFUL OF OPPORTUNITIES

Since the establishment of China-ASEAN dialogue relations in 1991,the two sides have been deepening their cooperation in an allround manner,yielding fruitful results in various fields.A review of the 30 years unfolds an extraordinary and exciting journey defined by tremendous progress.