惯性气流式红枣清选系统设计与试验   总被引：1，自引：0，他引：1  

史高昆  李景彬  丁龙朋  坎杂 《农业机械学报》2022,53(6):167-176

清选系统是气吸式红枣收获机的重要组成部分,降低清选含杂率、损失率和破损率是实现红枣收获机械化的关键技术。利用枣、杂惯性和流体力学特性差异,设计了一种惯性气流式红枣清选系统,并对其关键部件及结构参数进行设计和分析。采用Fluent软件探明了该清选系统内气流运动形成的“∞”形旋流有利于枣、杂的清选。为获得清选系统最佳工作参数,以气流速度、调节板开度为试验因素,以含杂率、损失率和破损率为评价指标,设计二次正交旋转组合试验。建立试验因素与指标间的回归模型,采用多目标优化算法进行参数优化,确定清选系统最优参数组合：气流速度为32.0 m/s,调节板开度为3.4 cm。在该条件下开展验证试验,得到含杂率、损失率和破损率分别为1.38%、3.37%和0.60%,与优化参数相比分别增加了0.06、0.12、0.03个百分点。该清选系统满足枣、杂清选作业要求。  相似文献   

Ocular surface physiology and aqueous tear secretion in cats of diverse cephalic conformations     

Jelena Oksa-Minaļto  David J. Maggs  Jekaterina Akimova  Aija Ilgaža  Lionel Sebbag 《Veterinary ophthalmology》2023,26(Z1):109-118

Objective

To describe normative ocular surface and aqueous tear testing data for cats of various cephalic conformation.

Animals studied

Fifty-three healthy adult cats (11 British Shorthair, 11 Burmese, 10 Devon Rex, 10 Scottish Fold, and 11 Sphynx).

Procedures

Blink rate, corneal tactile sensation (CTS), and Schirmer tear test with or without topical anesthesia (STT-1, STT-2) and with nasolacrimal stimulation (NL-STT1, NL-STT2) were assessed. Palpebral fissure length (PFL) and skull morphology were measured, and cephalic index (CI) and craniofacial ratio (CFR) calculated.

Results

Mean ± SD test results were as follows: blink rate (5.0 ± 2.3 blinks/min), CTS (3.2 ± 0.7 cm), STT-1 (11.2 ± 4.3 mm/min), STT-2 (6.7 ± 3.6 mm/min), NL-STT1 (13.4 ± 5.7 mm/min), NL-STT2 (13.5 ± 5.2 mm/min), and PFL (2.0 ± 0.2 cm). Corneal sensitivity did not differ significantly among breeds (p = .152) but was negatively correlated with body weight (r = −.32, p = .019). STT-1 significantly differed among breeds (p < .001) and was lowest in Sphynx cats (8.7 ± 4.3 mm/min). A positive correlation was detected between STT-1 values at 30 and 60 s (r = .98; p < .001). The nasolacrimal reflex significantly increased STT in anesthetized and unanesthetized eyes (approximately +100% and +20%, respectively; p ≤ .002). STT-1 tended to be higher in intact versus neutered cats (p = .062). Age did not impact any test result (p ≥ .085).

Conclusions

Normative data described here serve as a baseline for future studies assessing ocular surface disease in multiple feline breeds. Unlike dogs, brachycephalic cats did not have lower CTS or STT-1 than non-brachycephalic cats.  相似文献   

工科专业实践教学质量监控体系构建     

蒙贺伟  坎杂  曹卫彬  成斌 《计算机与农业》2011,(3):110-112,121

实践教学是与理论教学紧密联系又相对独立的一个非常重要的教学环节,在高校人才培养方案中起着理论教学不可替代的作用。从建立实践教学思想监控体系、组织监控体系、过程监控体系、制度监控体系、督导监控体系及评价考核体系等六个方面对实践教学监控体系的构建进行了探讨。  相似文献   

西藏萝卜育种现状及发展前景     

杨晓菊  扎西拉宗  陈锋 《西藏农业科技》2009,31(4):32-34

萝卜是西藏主要栽培的蔬菜作物之一，播种面积占蔬菜总面积的20．13％-23．49％。萝卜杂交育种在西藏起步较晚，只有8—9年时间，采取的方法主要是自交不亲和系与高代自交系两种方法。本文对萝卜在西藏的地位、育种现状及发展前景进行了论述。  相似文献   

Khimotsid for treatment and prevention of toxoplasmosis]     

M V Krylov  A N Sokolov  V I Za?onts  L A Korovitskaia  N A Zakharova 《Veterinariia》1976,(11):69-71

  相似文献   

粉碎玉米秸秆压缩特性试验研究     

刘富强  李景彬  坎杂  温宝琴 《农机化研究》2019,(1):169-173,179

粉碎玉米秸秆的压缩特性对玉米秸秆饲料化工艺的优化和设备的研制有着重要的影响。为此,利用万能材料试验机结合自制压缩装置,对不同筛网粉碎后的玉米秸秆(品种:SC704)进行压缩试验,深入研究含水率、粉碎粒度、压缩速度对粉碎玉米秸秆压缩特性的综合影响。根据二次回归通用旋转组合设计原理设计试验方案,通过试验分析建立了最大压缩力与含水率、粉碎粒度、压缩速度之间的回归模型。试验结果表明:当粉碎玉米秸秆压缩至300kg/m^3时,含水率对粉碎玉米秸秆可压缩性影响极显著,粉碎粒度及压缩速度对粉碎玉米秸秆可压缩性影响显著;最大压缩力随含水率的增大而减小、随粉碎粒度的增大而增大、随压缩速度的增大而增大。  相似文献   

棉秆切割性能的试验研究   总被引：6，自引：0，他引：6  

李景彬  葛云  朱江丽  黄勇  温宝琴  坎杂 《甘肃农业大学学报》2011,46(1):136-139

依据自制的秸秆切割性能试验台,对棉秆的切割性能进行了试验研究.通过对直刃刀、锤片型刀片、以及锯片型刀片3种刀具进行试验,得出最适宜切割棉秆的刀片为锤片型刀片,最佳切割转速为1 000～1 300r·min-1.  相似文献   

Effect of three bacterial isolates from a commercial hatchery on early red abalone (Haliotis rufescens) postlarvae     

Casandra Anguiano-Beltrán  Ricardo Searcy-Bernal  Adrián M. García-Ortega  Zaúl García-Esquivel  Enrique Valenzuela-Espinoza 《Aquaculture International》2012,20(5):993-1001

Three bacterial strains, GHrC11, GHrC13 and GHrC15, were isolated from an abalone postlarval culture system in a commercial farm at Baja California, México. The strains were phenotypically characterized and sequenced (16S rDNA). Strain GHrC11 was a Gram-positive coccobacillum, while strains GHrC13 and GHrC15 were Gram-negative bacilli. Strain GHrC11 was identified as Exiguobacterium sp. The strains GHrC13 and GHrC15 were identified as Vibrio splendidus. The effects of these strains for the development of early abalone postlarvae (2 days old) were evaluated following a completely randomized design with three replicates using 5-mL-volume Petri dishes as experimental units. The experiment considered two different bacterial concentrations of each strain (10³ and 10⁵?cells?ml^?1) and two controls (with and without the benthic diatom Navicula incerta). After 10?days of experimentation, the highest mortality (90?±?5.8?%) and the lowest growth rate (4.1?±?0.1?μm?day^?1) were recorded for the strain GHrC11. In contrast, the lower mortality (16.7?±?3.3?%) and the highest growth rate (11.2?±?0.9?μm?day^?1) corresponded to the control fed N. incerta. Our results suggest that pathogenic effects of these bacterial strains were stronger than any potential benefits derived from the ingestion of bacteria by early abalone postlarvae. In conclusion, the most pathogenic strain was GHrC11, and the intensity of pathogenicity could be ordered as Exiguobacterium sp.?>?V. splendidus (C13)?>?V. splendidus (C15).  相似文献   

残膜机械化回收技术   总被引：1，自引：0，他引：1  

高团结  马俊贵  坎杂 《农业工程》2014,4(3):10-13

地膜具有保墒、提高地温、抑制杂草生长和增产增收等作用,得到了广泛应用,并极大地促进了我国农业经济的发展。但是残留在土壤中的地膜极难降解,给农业生产和生态环境造成了巨大危害,残膜回收对于保护耕地、改善农田生态环境具有重要的意义。总结了国内外残膜回收技术的研究现状及研究方法,指出我国残膜回收机具存在的主要问题,提出了实施机械化残膜回收技术的建议,为机械化回收残膜的研究提供理论依据。   相似文献   

自走式奶牛精确饲喂机的单片机控制系统设计     

李亚萍  蒙贺伟  高振江  李辉  坎杂 《农机化研究》2016,(2):179-183

为了提高奶牛精确饲喂技术水平、降低成本、减少工作量、提高个体奶牛产奶量,在前期完成自走式奶牛精确饲喂机机械结构设计和牛场信息管理系统设计的基础上,通过单片机控制系统的设计,实现奶牛饲喂数据的接收、牛只的个体精确识别、装备的行进及精确投料,实现了个体奶牛的自动化及智能化饲喂。试验调试验证表明:饲喂机的最佳行进速度为0.6m/s,识别距离达65cm,系统响应时间为0.4s;个体奶牛识别率96%,个体牛只识别正确率100%,给料误差小于2%。  相似文献