[Objective] This study was conducted to discuss influence factors for safety full heading of machine-transplanted rice seedlings in cool-warm rice area. [Method] Effects of variety, seedling age and nitrogen fertilize...[Objective] This study was conducted to discuss influence factors for safety full heading of machine-transplanted rice seedlings in cool-warm rice area. [Method] Effects of variety, seedling age and nitrogen fertilizer dosage and strategy of machine-transplanted seedlings on safety full heading of machine-transplanted seedlings were investigated. [Result] During mechanized rice production in coolwarm rice area, mid-early-maturing cold-resistant varieties with growth periods no longer than 180 d could selected, and seedling age could controlled within 30-35 d; and the total amount of pure nitrogen should be less than 300 kg/hm^2, and the proportion of nitrogen fertilizer applied in later stages should be properly reduced. [Conclusion] Under this condition, safety full heading of rice is ensured, and the target yield is realized.展开更多
The general construction procedure of the steel middle pylon is briefly introduced. The alignment control of the pylon is carried out during the whole process of the construction. The control concept is extended to th...The general construction procedure of the steel middle pylon is briefly introduced. The alignment control of the pylon is carried out during the whole process of the construction. The control concept is extended to the manufacture stage. The manufacturing alignment error is strictly controlled in the segments precast process in factory, and the error is recognized and predicted precisely during the installation stage. The adjusting joints are employed to amend the accumulated error, which ensure that the steel pylon alignment could satisfy the precision requirements after installation.展开更多
文摘[Objective] This study was conducted to discuss influence factors for safety full heading of machine-transplanted rice seedlings in cool-warm rice area. [Method] Effects of variety, seedling age and nitrogen fertilizer dosage and strategy of machine-transplanted seedlings on safety full heading of machine-transplanted seedlings were investigated. [Result] During mechanized rice production in coolwarm rice area, mid-early-maturing cold-resistant varieties with growth periods no longer than 180 d could selected, and seedling age could controlled within 30-35 d; and the total amount of pure nitrogen should be less than 300 kg/hm^2, and the proportion of nitrogen fertilizer applied in later stages should be properly reduced. [Conclusion] Under this condition, safety full heading of rice is ensured, and the target yield is realized.
基金National Science and Technology Support Program of China ( No. 2009BAG15B02) Key Pro-grams for Science and Technology Development of Chinese Transportation Industry( No. 2008-353-332-180)
文摘The general construction procedure of the steel middle pylon is briefly introduced. The alignment control of the pylon is carried out during the whole process of the construction. The control concept is extended to the manufacture stage. The manufacturing alignment error is strictly controlled in the segments precast process in factory, and the error is recognized and predicted precisely during the installation stage. The adjusting joints are employed to amend the accumulated error, which ensure that the steel pylon alignment could satisfy the precision requirements after installation.
基金美國學術聯合會〔American Council of Learned Societies〕的“2010~2011年度中國人文研究獎助金〔American Humanities in China Research Fellowship〕”美國新澤西羅格斯大學文理學院歷史系爲本文的研究和撰寫提供的資助
