【摘要】 我国现在铁路编组场尾部平面调车全部采用人工拧手闸和下铁鞋的笨重而落后的作业方式。为了提高编组场的综合能力、解决峰头和峰尾的矛盾、改变尾部作业的技术落后状态,兰州西站与哈中心采用微机可控顶与停车顶结合的调速系统来解决尾部平面调车自动化问题。经过科学的分析论证与两股道的运用试验证明,微机可控顶、停车顶调速系统是比较理想的方案,为实现尾部平面调车自动化闯出了一条路子。更多还原

【Abstract】 The plant growth regulator EF was fractionated with different solvents to obtain chloroform, ethylacetate, ethanol and water soluble fractions. These fractions were used for vegetable plantation test in laboratory and in field. The results showed that among the four fractions of EF, the chloroform soluble fraction is the most active one, which had significant and stable effect on the increment of yields of both leafy and fruit vegetables.更多还原