Yields,growth and water use under chemical topping in relations to row configuration and plant density in drip-irrigated cotton

Background Water deficit is an important problem in agricultural production in arid regions.With the advent of wholly mechanized technology for cotton planting in Xinjiang,it is important to determine which planting mode could achieve high yield,fiber quality and water use efficiency(WUE).This study aimed to explore if chemical topping affected cotton yield,quality and water use in relation to row configuration and plant densities.Results Experiments were carried out in Xinjiang China,in 2020 and 2021 with two topping method,manual topping and chemical topping,two plant densities,low and high,and two row configurations,i.e.,76 cm equal rows and 10+66 cm narrow-wide rows,which were commonly applied in matching harvest machine.Chemical topping increased seed cotton yield,but did not affect cotton fiber quality comparing to traditional manual topping.Under equal row spacing,the WUE in higher density was 62.4%higher than in the lower one.However,under narrow-wide row spacing,the WUE in lower density was 53.3%higher than in higher one(farmers’practice).For machine-harvest cotton in Xinjiang,the optimal row configuration and plant density for chemical topping was narrow-wide rows with 15 plants m-2 or equal rows with 18 plants m-2.Conclusion The plant density recommended in narrow-wide rows was less than farmers’practice and the density in equal rows was moderate with local practice.Our results provide new knowledge on optimizing agronomic managements of machine-harvested cotton for both high yield and water efficient.

265/35R22 102Y轿车子午线轮胎的设计

介绍265/35R22 102Y轿车子午线轮胎的设计。结构设计:外直径739 mm,断面宽287 mm,行驶面宽度227.9mm,行驶面弧度高20.9mm,胎圈着合直径559.2mm,胎圈着合宽度262mm,断面水平轴位置(H1/H2)1.06,胎面采用TH201花纹并优化花纹节距排列,花纹深度7mm。施工设计:胎面采用三方四块结构,带束层采用2层3×0.30HT钢丝帘线,胎体采用2层1100dtex/2DSP聚酯帘布,采用一次法成型机成型、双模液压硫化机硫化。成品性能试验结果表明,轮胎的外缘尺寸、强度性能、脱圈阻力、耐久和低气压耐久性能及高速性能均达到相应设计和国家标准要求,滚动阻力达到欧盟标签法限值要求。

T155/90R18 T型备用轿车子午线轮胎的设计

介绍T155/90R18 T型备用轿车子午线轮胎的设计。结构设计:外直径731 mm,断面宽152 mm,行驶面宽度108. 5 mm,行驶面弧度高5. 4 mm,胎圈着合直径457. 6 mm,胎圈着合宽度127 mm,断面水平轴位置(H1/H2)1. 04,采用直线形纵向主花纹沟和斜向横向花纹沟,主花纹深度3. 8 mm,花纹周节数52,花纹饱和度71. 8%。施工设计:胎体采用2层1440dtex/2 DSP聚酯帘布,带束层采用2+2×0. 32ST钢丝帘线,矩形钢丝圈结构;采用一次法成型机成型、双模液压硫化机硫化。成品性能试验结果表明,成品轮胎的充气外缘尺寸、强度性能、脱圈阻力、耐久性能和高速性能均符合相应的国家标准要求。

液压支架立柱激光熔覆再制造工艺研究

采用镍基合金粉末对液压支架立柱中缸筒、活柱进行激光熔覆试验,分析不同工艺参数条件下的熔覆层质量,得到适合立柱中缸筒、活柱基体激光熔覆的最优工艺参数(激光功率3 500 W,扫描速度7 mm/s),并将其运用于ZY 10000/25/55 D型大修液压支架立柱中缸筒外表面激光熔覆过程。结果表明,最优工艺参数适用于液压支架立柱中缸筒、活柱激光熔覆工艺。