气吹悬浮供种滚筒式播种机吸附取种理论分析

根据新疆番茄穴盘育苗排种器播种过程对种子的"单粒单穴"的农业工艺要求,创新设计了一种基于气吹悬浮供种方式的滚筒式番茄育苗播种机,解决了精密播种过程中多粒、空穴、漏播等问题。通过介绍播种机的主要结构及其播种原理,分析排种器吸附取种过程及种子瞬时吸附受力,得出滚筒吸附取种的条件。通过样机试验及吸附取种理论分析,得出影响播种机取种性能主要指标的主次关系依次为种箱结构气室正压力、吸孔的直径、滚筒转速。当种箱结构气室正压力为2.0k Pa、吸孔直径为1.5mm、滚筒转速为12r/min时,取种综合效果效果较理想。同时,通过试验设计及数据处理,得出较优水平组合,统计结果为:单粒率92.5%,多粒率5.3%,空穴率3.0%。气吹悬浮供种滚筒式育苗排种器的播种效果较佳,可满足农艺要求。     

广佛手不同套种模式下根际土壤理化性质及有效态元素的变化

研究3种套种模式（分别套种广藿香、金钱草和穿心莲）对广佛手根际土壤理化性质和有效态元素的影响。结果表明,广佛手与广金钱草套种土壤pH最低（pH 6.1）,广佛手单作土壤pH最高（pH 6.4）;与广佛手单作相比,3种套种模式下土壤有机质含量和土壤碱解氮含量有所下降,其中与广金钱草套种下降最为显著,广藿香套种组土壤碱解氮与广佛手单作组无显著差异;穿心莲套种组比广佛手单作组土壤有效磷、速效钾含量分别提高了8.07%和3.41%,说明套种穿心莲后土壤有效磷、速效钾含量明显增加;广藿香套种组根际土壤交换性钙、镁,有效铜的含量降低,有效锌、铁、锰、硼的含量增加;广金钱草套种组根际土壤的交换性钙、镁,有效铜、锌、铁的含量降低,有效锰、硼的含量增加;穿心莲套种组根际土壤交换性钙、镁、有效铜、锰的含量降低,有效锌、铁、硼的含量增加;PCA分析结果表明碱解氮,速效钾,有效磷、铜、锌、铁是影响广佛手生长的特征因素;同时不同套种模式提高了整体经济效益。不同套种模式显著影响了广佛手根际土壤理化性质和有效态微量元素的含量,为广佛手套种模式的应用提供参考。     

北方地区高粱籽粒寄藏禾谷镰孢菌群产毒素化学型的分子检测

禾谷镰孢菌群是高梁籽粒主要寄藏真菌[1]。禾谷镰孢菌侵染高粱籽粒的代谢过程中可以产生多种对人类和动物有害的真菌毒素,其中脱氧雪腐镰孢烯醇（deoxynivalenol,DON）、雪腐镰孢烯醇（nivalenol,NIV）、3-乙酰脱氧雪腐镰孢菌烯醇（3-acetyldeoxynivalenol,3-AcDON）和15-乙酰脱氧雪腐镰孢菌烯醇（15-acetyldeoxynivalenol,15-AcDON）毒性较强[2-3]。     

花生收获挖掘铲设计及优化

为提高平顶山丘陵地区的花生收获质量及效率，设计了一种结构简单、破土及碎土性能良好的花生收获挖掘铲，并对其主要参数进行优化分析。分析结果:vm=0.64 m/s，δ=120°，l=0.45 m，h=0.2 m，b=0.5 m，θ=15°。研究结论为提高花生收获质量及效率奠定理论基础。      

Common strategies in silkworm disease resistance breeding research

The silkworm, which is considered a model invertebrate organism, was the first insect used for silk production in human history and has been utilized extensively throughout its domestication. However, sericulture has been plagued by various pathogens that have  caused significant economic losses. To enhance the resistance of a host to its pathogens,numerous strategies have been developed. For instance, gene-editing techniques have been applied to a wide range of organisms, effectively solving a variety of experimental problems. This review focuses on several common silkworm pests and their pathogenic mechanisms, with a particular emphasis on breeding for disease resistance to control multiple types of silkworm diseases. The review also compares the advantages and disadvantages of transgenic technology and gene-editing systems. Finally, the paper provides a brief summary of current strategies used in breeding silkworm disease resistance, along with a discussion of the establishment of existing technologies and their future application prospects. © 2023 Society of Chemical Industry.     

播期对下茬青贮玉米物质生产特性的影响及气象条件分析

以郑单958和高油4515两个粮饲兼用型青贮玉米为下茬作物,设置5个播期处理,研究了播期对玉米物质生产特性的影响,并进行了气象条件分析.结果表明,7月5日、7月12日、7月19日三个播期处理的热量和水分条件基本上能够满足青贮玉米所需;7月5～19日播种,郑单958可收获青体产量63.55～71.9t//hm2,高油4515可收获青体产量60.71～64.67t/hm2;7月26日以后播种,有效积温不足,且低温造成生育期延迟性障碍,两个青贮玉米品种均没有鲜稳产量,秸秆干物质含量和青体产量显著降低,因此,下茬复种郑单958和高油4515最迟不宜晚于7月26日.     

联合作业打瓜取籽机关键部件的设计与研究

打瓜是新疆地区的主要经济作物,其生产过程机械化程度低,严重制约了新疆大田生产的发展。为此,拟定了一种将打瓜破碎和分离清选的设计方案,阐述了破碎装置的工作原理、结构组成和结构尺寸的设计。通过取样试验测得打瓜样本的平均值,设计了对辊破碎机构的间隙极限值,间隙极限值分别为dmax=1 0 0 mm,dmin=2 0 mm。阐述了籽瓤分离装置的工作过程、结构布局和结构尺寸的设计,设计了一种双滚筒式分离清选装置。通过取样试验测得新疆地区打瓜籽的三轴尺寸样本平均值,确定了内外筛网孔的尺寸,内外尺寸分别为20mm≤D1≤25 mm,5 mm≤D2≤8 mm。通过对破碎、分离清选装置的设计,提高了打瓜取籽机的工作效率,降低了破损率,对大面积种植模式,尤其是新疆地区具有促进作用。     

不同银杏品种枝丫具缘纹孔变异特性

以我国的'马铃3'和日本的'藤九郎'、'金兵卫'、'黄金丸'及'岭南'5个银杏品种为试材,对其应压木和对应木枝丫具缘纹孔变异特性进行研究.结果表明,5个银杏品种具缘纹孔均为南洋杉A型,未见B型;径壁具缘纹孔多呈单列,少数两列且对列;弦壁具缘纹孔稀少,其直径约为径壁直径的79.88%～89.37%,通常集中在晚材最后数列管胞上;边材具缘纹孔直径近髓心处大;从应压木边材至对应木边材,具缘纹孔直径变化曲线大体呈"V"型或"N"型;对应木具缘纹孔口直径为应压木的87.71%,其径壁纹孔口直径较弦壁的小,而应压木则相反;'马铃3'应压木管胞弦壁和'藤九郎'对应木管胞径壁上均发现单纹孔.另外,从具缘纹孔特性角度,对银杏与其它裸子植物进行了比较分析.     

Effect of Soil Drying Intensity During an Experimental Drying-Rewetting Event on Nutrient Transformation and Microbial Community Composition

Soil drying-rewetting(DRW) events affect nutrient transformation and microbial community composition; however, little is known about the influence of drying intensity during the DRW events. Therefore, we analyzed soil nutrient composition and microbial communities with exposure to various drying intensities during an experimental drying-rewetting event, using a silt loam from a grassland of northern China, where the semi-arid climate exposes soils to a wide range of moisture conditions, and grasslands account for over 40% of the nation's land area. We also conducted a sterilization experiment to examine the contribution of soil microbes to nutrient pulses. Soil drying-rewetting decreased carbon(C) mineralization by 9%–27%. Both monosaccharide and mineral nitrogen(N) contents increased with higher drying intensities(drying to ≤ 10% gravimetric water content), with the increases being 204% and 110% with the highest drying intensity(drying to 2% gravimetric water content), respectively, whereas labile phosphorus(P)only increased(by 105%) with the highest drying intensity. Moreover, levels of microbial biomass C and N and dissolved organic N decreased with increasing drying intensity and were correlated with increases in dissolved organic C and mineral N, respectively,whereas the increases in labile P were not consistent with reductions in microbial biomass P. The sterilization experiment results indicated that microbes were primarily responsible for the C and N pulses, whereas non-microbial factors were the main contributors to the labile P pulses. Phospholipid fatty acid analysis indicated that soil microbes were highly resistant to drying-rewetting events and that drought-resistant groups were probably responsible for nutrient transformation. Therefore, the present study demonstrated that moderate soil drying during drying-rewetting events could improve the mineralization of N, but not P, and that different mechanisms were responsible for the C, N, and P pulses observed during drying-rewetting events.     

残膜回收机单组仿形搂膜机构的设计与试验

搂膜作业是新疆目前残膜回收的主要工作方式,在残膜回收机回收工作过程中,因棉地环境复杂,现有残膜回收机整体仿形搂膜效果差,使得搂膜弹齿无法对起伏程度不同的棉地同时进行单组仿形搂膜,造成残膜回收率低等问题,针对此问题,该文提出了一种单组仿形搂膜机构。通过对该机构进行理论设计,利用搭建的土槽台架试验装置,以弹齿数量、试验车速度、弹齿直径为影响因素,搂膜率为评价指标,进行了二次旋转正交组合试验。通过Design-Expert 8.0.6数据分析软件,建立各影响因素与指标的数学回归模型,分析了显著因素与评价指标之间的关系,优化试验参数,确定最优参数组合:弹齿数量5个,弹齿直径12 mm,试验车速度1.85 m/s。根据该试验参数组合,进行台架试验验证,结果表明:优化参数组合下的搂膜率88.5%,优化预测模型可靠。通过在新疆昌吉五家渠共青团农场对站立棉秸秆的田间进行搂膜试验,表明该搂膜机构能够满足残膜回收的技术要求,为单组仿形搂膜机具的设计提供了参考依据。