黄腐酸抗旱营养剂对小麦和玉米生长的影响

研究了黄腐酸旱地龙拌种、浇灌以及喷施对小麦和玉米生长的影响。结果表明:拌种时间为30 min时可提高小麦的发芽率和促进小麦苗期生长;浇灌试验中,正常供水条件下,浓度为600倍的稀释溶液相比对照可显著降低叶绿素a和类胡萝卜素含量,分别降低17.7%和15.6%;而干旱胁迫下,稀释480倍处理相比对照显著提高叶绿素a含量达24%;浇灌FA可显著提高田间玉米花粒期株高和Chla+b,分别提高7%和17%,喷施处理提高叶片净光合速率和水分利用效率,分别为25%和28%,而浇灌处理提高了62%和45%;浇灌FA显著提高田间小麦苗期和返青期叶绿素含量。     

水泥搅拌桩处理软土路基的试验分析

通过试验数据分析,对水泥搅拌桩浆喷和粉喷的处理方案进行了比较,结果认为：粉喷更适用于含水量大、塑性指数高的软土路基处理。     

双层桨叶单轴混合机的结构与特点

文章旨在分析双层桨叶单轴混合机的结构和混合原理。通过对混合机的机体、转子、卸料门及控制机构、传动部分、液体添加系统、气包喷吹系统关键结构的详细分析,了解其独特的混合原理和优良特性。该机具有混合均匀度高CV≤5%(可达2%~3%)、残留量低(≤0.1%)、生产效率高、使用维修方便等特点,在国内外饲料添加剂预混合生产中应用越来越广泛。     

Dough and bread made from high- and low-protein flours by vacuum mixing: Part 1: Gluten network formation

The effects of reduced headspace pressure on the development of gluten network in doughs made from both high-protein flour (HPF) and low-protein flour (LPF) were investigated. The effect of vacuum mixing was found to be dependent on both flour-type and mixing-time. A significant increase in dough extensibility was observed when the HPF dough was mixed under moderate vacuum of −0.04 MPa for 3 min as compared to the one mixed under atmospheric pressure for the same duration. This was attributed to the formation of a more extensive gluten network associated with an increased disulphide bond density and a significantly higher β-sheet to β-turn ratio. On the other hand, over-mixing was observed in the LPF dough that was mixed for 5 min under atmospheric pressure. Applying moderate vacuum of −0.04 MPa allowed the LPF dough to withstand longer mixing time, as indicated by its increased disulphide bond density and biaxial extensibility compared to the control dough mixed under atmospheric pressure. Results of this study suggest the potential of applying vacuum to reduce the mixing time required for high protein flour and to prevent the over-mixing of low protein flour.     

Impact of ethanol,succinic acid,and the combination thereof at levels produced during sponge fermentation on hard wheat,soft wheat,and durum wheat farinograph rheology

The sponge and dough mixing process is one of the most common in the world, yet the mechanistic understanding of this process has yet to be sufficiently explored. In this study, aqueous solutions of ethanol, succinic acid, and their combination were prepared at concentrations intended to replicate fermentation times of 3, 4 and 6 h. These solutions were added to a farinograph mixer to make dough using hard wheat, soft wheat, and durum wheat flour. The results indicate that these yeast metabolites (ethanol, succinic acid) impact the mixing resistance, peak mixing value, and dough mixing stability in each of the flour types, likely primarily affected by the ratios of gliadin to glutenin and LMW glutenin in each flour type. Results suggest a stabilizing non-covalent interaction imparted by gliadin at peak mixing time, a stabilizing effect of HMW glutenin during break down, and synergistic effects of ethanol and succinic acid that leads to a faster rate of breakdown in later stages of mixing. It also suggests an increase in mixing resistance when acidulants are added to durum wheat dough. Taken together, this study adds new insights on the sponge and dough mixing process in a way that has not previously been conducted.     

混播比例和施氮肥对箭筈豌豆/燕麦草地根系特性的影响

豆科和禾本科牧草混播是栽培草地的重要模式之一,能显著改善土壤,提升系统可持续生产能力。牧草根系是土壤有机质返还的重要来源,但混播草地中牧草根系特性的变化尚不清楚。以箭筈豌豆和燕麦草地为对象,研究了不同施氮肥水平和混播比例下其根生物量、根性状的变化。结果表明:1)混播比例和施氮肥对草地根生物量和根性状有显著交互作用,混播草地根生物量显著大于单播;与高氮肥处理相比,根生物量在低、中氮肥处理下更高;高氮肥对根长、比根长、根表面积和比根面积在植物生长前期表现为抑制作用,在生长后期随混播中箭筈豌豆比例的增大,抑制作用减轻。2)混播条件下土壤硝态氮含量大于单播,而土壤铵态氮含量仅在乳熟期时大于单播,且随混播中箭筈豌豆比例增大,矿质氮含量增加;施氮肥对0~30 cm土层中的矿质氮含量有显著影响,其含量在施氮肥100 kg·hm^-2下最高,不施肥下最小。3)根生物量与土壤硝态氮含量间显著正相关,根长、根表面积、根体积与土壤硝态氮含量间显著负相关。综上,混播中箭筈豌豆比例的增加有助于改善土壤矿质氮,优化混播草地根性状。     

植保机在线混药系统的设计及混药性能试验

为提高植保机喷雾作业中的农药利用率,设计了一种在线混药系统。混药系统主要包括取水单元、取药单元、混合器和控制单元。系统工作时,控制单元控制取水单元和取药单元抽取水溶液和农药,注入混合器混合,混合液经隔膜泵加压后经过喷头喷施。基于计算流体力学理论,建立内置7块扰流板且注药口和注水口沿边壁垂直分布并正对第1块扰流板的圆柱形静态混合器模型,运用Fluent软件对模型进行数值分析,结果常压(0.1MPa)时,混合器出口处药水混合均匀性变异系数为2.2%,药水混合效果最佳,但注药口有药剂回流现象,故提出药剂加压的模拟方案。药剂加压1MPa时,注药口无药剂回流现象,药水混合均匀性变异系数为2.0%,药水混合效果优于常压。用胭脂红溶液替代农药进行试验,加压状态下,混药系统喷头处混药稳定性最大相对误差为4.301%,药水混合变异系数最大,为3.989%,混药性能优于常压,与仿真结果基本吻合;对在线混药系统进行隔膜泵变工况试验,结果水流量在35～140 L/min时,药水配比为(1∶300)～(1∶3 000)时,在线混药系统混合均匀性系数最大,为4.670%。     

Recent Research and Application ofSuper High Strength High Performance Concrete

Based on author's many experimental results, giving four items of key technique for preparing super high strength high performance concrete (SHPC); summarizing main benefits of SHPC; introducing briefly the current situation of application of SHPC;the problems of pumpability, brittleness and volume stability of SHPC are analyzed and discussed.     

甘肃省春小麦根病化学防治技术研究

１９９１－１９９５上经室内、田间试验研究,筛选出三唑酮、烯唑醇、丙环唑等三唑类坐菌剂为防治小麦根病的有效药剂,其中以２５％丙环唑乳油拌种病增产效果最好,白穗防效可达９０％以上;不同剂量试验结果,按种重０．０５－０．１％拌种经济有效;通过药剂剂型、施药时期和方法研究表明,改变药剂剂型和施药方法,可延长药效、提高防效;湿抖闷种防病增产效果优于干拌。     

杉木半穿刺线虫寄主及混交林效应的研究

杉木半穿刺线虫新发现三种寄主植物杉木、柳杉、野柿,原国内外报道寄主植物有柑桔、甜橙、橄榄、葡萄、紫丁香、核桃、杏树、海棠、苹果、梨、柿树、构桔、黄杨、桂花、兰棕等．杉木与非杉木半穿刺线虫寄主植物马尾松、酸枣、泡桐、火力楠、湿地松、楠木、檫树、油桐、枣柏、木荷等混交,可大大降低虫口密度,促进杉木生长,是一种较好的控制线虫密度的营林措施;杉木与杉木半穿刺线虫寄主植物柳杉混交,其虫口密度大大增加