在高肥条件下,研究了不同水氮组合对强筋小麦品种济麦20籽粒产量、蛋白质含量、蛋白质组分和籽粒品质的影响。结果表明影响小麦籽粒品质的主导因素是灌水。相同施氮水平下,各灌水处理的籽粒蛋白质含量、单体蛋白含量均显著低于不灌水处...在高肥条件下,研究了不同水氮组合对强筋小麦品种济麦20籽粒产量、蛋白质含量、蛋白质组分和籽粒品质的影响。结果表明影响小麦籽粒品质的主导因素是灌水。相同施氮水平下,各灌水处理的籽粒蛋白质含量、单体蛋白含量均显著低于不灌水处理,但不同灌水处理间无显著差异。随灌水次数增加,不溶性谷蛋白(高分子量谷蛋白)含量呈下降趋势,可溶性谷蛋白(低分子量谷蛋白)含量呈上升趋势,谷蛋白聚合指数(不溶性谷蛋白含量/谷蛋白总量)降低,粉质仪参数(面团稳定时间和形成时间)也相应降低,表明灌水次数增加导致籽粒品质变劣的主要原因是不溶性谷蛋白积累减少。施氮168 kg/hm2条件下,氮肥拔节期全量追施处理的籽粒产量不降低,而其籽粒品质显著优于分次施肥处理(50%基施、50%拔节期追施),且与240 kg N/hm2分次施用处理差异不显著。因此,在高产水平下,氮肥全量追施可作为兼顾籽粒产量和品质的推荐运筹模式。展开更多
Welding solidification cracking of alloys is associated with the range of solidification temperature that can be greatly affected by the amount of refractory metals and other additives. In this work, solidification cr...Welding solidification cracking of alloys is associated with the range of solidification temperature that can be greatly affected by the amount of refractory metals and other additives. In this work, solidification cracking of Ni-28W-6Cr alloy with high W content was studied by gas tungsten arc welding, showing that the welding current, alloying elements and precipitates all affect the cracking susceptibility. The lengths of cracks increase linearly with the welding current in the range from 150 to 250 A. The relatively high cracking susceptibility is mainly attributed to the high content of Si, which tends to segregate with other elements including W, Cr, Mn as films or components with low melting point in the last solidification stage and weaken the binding force of grain boundaries. Moreover, the existence of precipitated continuous eutectic M_6C carbides in the grain boundaries also acts as nucleation sites of crack initiation, and the cracks often propagate along solidification grain boundary.展开更多
为了解氮磷配施对西北地区冬小麦产量和养分利用效率的影响,在甘肃凉州区黄羊镇甘肃农业大学试验农场开展了4个施肥处理(N165P105:165 kg N.hm-2+105 kg P2O5.hm-2;N165P165:165 kg N.hm-2+165kg P2O5.hm-2;N225P105:225 kg N.hm-2+105 ...为了解氮磷配施对西北地区冬小麦产量和养分利用效率的影响,在甘肃凉州区黄羊镇甘肃农业大学试验农场开展了4个施肥处理(N165P105:165 kg N.hm-2+105 kg P2O5.hm-2;N165P165:165 kg N.hm-2+165kg P2O5.hm-2;N225P105:225 kg N.hm-2+105 kg P2O5.hm-2;N225P165:225 kg N.hm-2+165 kg P2O5.hm-2)的大田试验。结果表明,4个施肥处理中,N165P105、N225P165和N165P165三个处理间产量差异不显著,但均显著高于N225P105;N165P105是河西绿洲冬小麦高产节肥的最佳施肥处理。少施N肥有利于WUE的提高(7.89%),而氮磷合理配施才能获得较高的WUE。多施N、P肥可增加N(36.72%)和P(58.94%)的消耗量,但明显降低N(44.48%)、P(53.50%)利用效率,不同处理间N、P利用效率差异显著或极显著,但N、P肥在养分利用上彼此影响不大。因此,肥料的合理配施是提高养分利用效率、实现西北地区高产的主要途径。展开更多
Debris flows in essence are the process of mass transportation controlled by the constitution featured by a wide-ranged distribution of grain size. Debris-flow samples of different densities collected from different r...Debris flows in essence are the process of mass transportation controlled by the constitution featured by a wide-ranged distribution of grain size. Debris-flow samples of different densities collected from different regions and gullies reveal that cumulative curve of grain composition, in particular for debris flows of high density, ρ5〉2 g/cm^3, can be fitted well by exponential function with exponents varying with regions and gullies. Debris flows fall into a narrow-valued domain of the exponent, as evidenced by Jiangjiagou Gully （JJG） with high occurrence frequency of debris flows. Furthermore, fractality of grain composition and porosity have been derived from cumulative curves in a certain size range, a range that determines the upper limit of grains constituting the matrix of debris flows. One can conclude that fractal structure of porosity plays crucial roles in soil fluidization that initiates debris flows, and debris flows occur at some range of fractal dimension, in coincidence with field observations.展开更多
文摘在高肥条件下,研究了不同水氮组合对强筋小麦品种济麦20籽粒产量、蛋白质含量、蛋白质组分和籽粒品质的影响。结果表明影响小麦籽粒品质的主导因素是灌水。相同施氮水平下,各灌水处理的籽粒蛋白质含量、单体蛋白含量均显著低于不灌水处理,但不同灌水处理间无显著差异。随灌水次数增加,不溶性谷蛋白(高分子量谷蛋白)含量呈下降趋势,可溶性谷蛋白(低分子量谷蛋白)含量呈上升趋势,谷蛋白聚合指数(不溶性谷蛋白含量/谷蛋白总量)降低,粉质仪参数(面团稳定时间和形成时间)也相应降低,表明灌水次数增加导致籽粒品质变劣的主要原因是不溶性谷蛋白积累减少。施氮168 kg/hm2条件下,氮肥拔节期全量追施处理的籽粒产量不降低,而其籽粒品质显著优于分次施肥处理(50%基施、50%拔节期追施),且与240 kg N/hm2分次施用处理差异不显著。因此,在高产水平下,氮肥全量追施可作为兼顾籽粒产量和品质的推荐运筹模式。
基金New Century Excellent Talents in University of China (NCET-06-0879)the National Natural Science Foundation of China (50971102)+2 种基金NPU Foundation for Fundamental Research (NPU-FFR-JC200808)the Fund of the State Key Laboratory of Solidification Processing (NPU) (16-TZ-2007 and 39-QZ-2009)the Programme of Introducing Talents of Discipline to Universities (08040)
基金supported by the National Key Research and Development Program of China(Grant No.2016YFB0700404)the National Natural Science Foundation of China(Grant Nos.51601213and 51501216)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA02004210)the Talent development fund of Shanghai(Grant No.201650)
文摘Welding solidification cracking of alloys is associated with the range of solidification temperature that can be greatly affected by the amount of refractory metals and other additives. In this work, solidification cracking of Ni-28W-6Cr alloy with high W content was studied by gas tungsten arc welding, showing that the welding current, alloying elements and precipitates all affect the cracking susceptibility. The lengths of cracks increase linearly with the welding current in the range from 150 to 250 A. The relatively high cracking susceptibility is mainly attributed to the high content of Si, which tends to segregate with other elements including W, Cr, Mn as films or components with low melting point in the last solidification stage and weaken the binding force of grain boundaries. Moreover, the existence of precipitated continuous eutectic M_6C carbides in the grain boundaries also acts as nucleation sites of crack initiation, and the cracks often propagate along solidification grain boundary.
文摘为了解氮磷配施对西北地区冬小麦产量和养分利用效率的影响,在甘肃凉州区黄羊镇甘肃农业大学试验农场开展了4个施肥处理(N165P105:165 kg N.hm-2+105 kg P2O5.hm-2;N165P165:165 kg N.hm-2+165kg P2O5.hm-2;N225P105:225 kg N.hm-2+105 kg P2O5.hm-2;N225P165:225 kg N.hm-2+165 kg P2O5.hm-2)的大田试验。结果表明,4个施肥处理中,N165P105、N225P165和N165P165三个处理间产量差异不显著,但均显著高于N225P105;N165P105是河西绿洲冬小麦高产节肥的最佳施肥处理。少施N肥有利于WUE的提高(7.89%),而氮磷合理配施才能获得较高的WUE。多施N、P肥可增加N(36.72%)和P(58.94%)的消耗量,但明显降低N(44.48%)、P(53.50%)利用效率,不同处理间N、P利用效率差异显著或极显著,但N、P肥在养分利用上彼此影响不大。因此,肥料的合理配施是提高养分利用效率、实现西北地区高产的主要途径。
基金N ationalN aturalScience Foundation ofChina,N o.40101001N o.40025103
文摘Debris flows in essence are the process of mass transportation controlled by the constitution featured by a wide-ranged distribution of grain size. Debris-flow samples of different densities collected from different regions and gullies reveal that cumulative curve of grain composition, in particular for debris flows of high density, ρ5〉2 g/cm^3, can be fitted well by exponential function with exponents varying with regions and gullies. Debris flows fall into a narrow-valued domain of the exponent, as evidenced by Jiangjiagou Gully （JJG） with high occurrence frequency of debris flows. Furthermore, fractality of grain composition and porosity have been derived from cumulative curves in a certain size range, a range that determines the upper limit of grains constituting the matrix of debris flows. One can conclude that fractal structure of porosity plays crucial roles in soil fluidization that initiates debris flows, and debris flows occur at some range of fractal dimension, in coincidence with field observations.
