模糊控制技术在多工位输送机中的应用-基于Fuzzy-Control软件

多工位输送机是一种可用在农药和化肥等农资产品纸塑包装后的装箱设备,其工作位置的定位要求快速准确,采用传统步进电机的开环控制难以达到要求.为此,以S7-300型PLC为平台,采用Fuzzy-Control软件运用模糊控制技术进行闭环设计,提高了设备定位的准确性.     

一种检测乳过氧化物酶方法的建立

【目的】建立一种简便、快速、精确的乳过氧化物酶（LP）检测方法。【方法】以ABTS为底物，利用动力学方法，建立了检测LP含量的ABTS法，并以优化后的体系检验ABTS法的精确度。【结果】以ABTS法检测LP含量的最佳反应条件为：吸收波长416nm，作用时间100s，pH5．5，ABTS浓度2mmol／L，H2O2浓度5mmol／L，工作温度25℃（室温）。经检验，该法的批内变异系数为2．39％，批间变异系数为3．42％，相关系数（R2）为0．9953，准确误差均未超过5．00％。【结论】以ABTS法检测LP精密度和准确度均较好，且操作步骤比较简便、快速，实现了对LP的简便、快速、精确检测。     

藤编原料植物青藤的扦插繁殖试验初报

本试验开展了青藤扦插繁殖试验,通过扦插季节、植物生长调节剂、遮阳对比试验,总结出了青藤的扦插繁殖技术,既可以解决藤编原料问题,同时又能达到保护野生植物资源的目的。     

4种豆科牧草种子对绵羊消化道作用的反应

以4种野生豆科牧草苦豆子(Sophora alopecuroide)、线叶野豌豆(Vicia tenuifolia)、光果甘草(Glycyrrhizae glabrae)、罗马苜蓿(Medicago romanica)种子为研究对象,测定各种子在绵羊消化道作用前后的形态、生物学特性变化以及在绵羊消化道内的运移和排放规律。结果表明,4种种子排放过程均符合高斯模型,且苦豆子、线叶野豌豆、光果甘草排放峰值均出现在饲喂后24~36h,罗马苜蓿种子排放峰值则出现在18~30h。苦豆子、线叶野豌豆、光果甘草和罗马苜蓿种子总回收率分别为14.513%、4.463%、10.811%、4.608%,在绵羊消化道内的平均滞留时间分别为36.3、29.6、31.2和31.9h。除苦豆子外,其它3种植物种子在经过消化道后单粒重显著降低(P0.05),4种种子消化后的形状指数较经过消化道前显著减小。经过绵羊消化道后种皮颜色加深,纹理模糊,出现褶皱及明显侵蚀斑。与经过消化道前比较,4种植物种子经过消化道后的发芽率均有显著提高,其中发芽率提高效果最明显的时间段在消化24~48h后。消化道作用可有效打破苦豆子、线叶野豌豆、光果甘草、罗马苜蓿种子的硬实,4种植物种子均可通过绵羊消化道传播。     

AGA-FAHP在工程项目评标中的应用

根据目前工程项目评标过程中一些定性指标无法定量化的问题,提出了基于加速遗传算法的模糊层次分析法(AGA-FAHP),分析了其具体的操作步骤,探讨了如何应用AGA-FAHP方法在工程项目评标中科学、合理地选择中标人,以保证最优者中标.     

反刍动物营养学发展现代化进程的回顾及其展望

文章在回顾反刍动物营养学发展的现代化进程的基础上,分析了当前反刍动物营养学的发展趋势,并对其面临的历史任务和优先研究领域进行了论述和展望。     

Bioprospection of Microalgae and Cyanobacteria as Biocontrol Agents Against Vibrio campbellii and Their Use in White Shrimp Litopenaeus vannamei Culture

Vibrio spp. are the most common and harmful shrimp pathogenic bacteria; however, microalgae and cyanobacteria have the ability to produce antimicrobial substances against these species. In this study, the organic and aqueous extracts of 28 species of marine microalgae and cyanobacteria were screened against Vibrio campbellii M1. Two of these phytoplankton species with antibacterial activity in aqueous extracts (Dunaliella tertiolecta and Skeletonema costatum) and nontoxic to brine shrimp Artemia franciscana nauplii were used to evaluate their anti‐Vibrio effect when used as green‐water cultures in Vibrio‐challenged white shrimp Litopenaeus vannamei cultures. No differences in mortality of juvenile L. vannamei were observed between treatments tested, suggesting that the pathogenicity of V. campbellii could be related to the growth stage of shrimp. The proximal composition of D. tertiolecta and S. costatum was in the recommended range for penaeid shrimp nutrition, allowing shrimp supplemented with these microalgae to have significantly greater total length and weight than control shrimp. Shrimp supplemented with S. costatum presented the highest values of organic mass (11.48 mg/organism) and growth rate (0.31 mg/d) in comparison to D. tertiolecta. These results indicate that microalgae are not only capable of producing antibacterial compounds against Vibrio but can also help shrimp nutrition.     

树形结构对果树生产能力的影响分析

果树树形与结构是影响果树产量的重要因素,笔者结合国内外的研究状况,综述了不同树形结构对光能利用率、营养与生殖、抗逆性、产量品质、实际生产的影响,指出适宜的栽植密度、合理的树形结构是保证果园光照良好,产量和品质提高的重要措施。     

农业院校非英语专业学生口语僵化的激活实验研究

非英语专业大学生英语口语中的语言僵化是一个普遍现象。本文通过教学实践和调查具体分析了大学生口语僵化的原因，从而制定出了口语激活策略，从教学理念、教学方法和考试模式三个方面进行改革。通过一年的教学实践，学生在口语表达时的流利程度、语法词汇的正确使用和交际能力方面都有了显著的提高，而且综合英语能力也有很大提高。实验结果证明，非英语专业大学生的口语僵化是可以被激活的。     

Enzyme activities and diuron persistence in soil amended with vermicompost derived from spent grape marc and treated with urea

Mineral fertilizers, organic amendments, and pesticides are inputs commonly used in conventional farming practices. The aim of this study was to evaluate the effects of single or combined applications of spent grape marc-vermicompost, urea, and/or diuron on soil-enzyme activities and the persistence of this herbicide in soils with low organic carbon content. The application of vermicompost enhanced dehydrogenase (DHase) enzyme activity over time but altered soil urease activity to a very limited extent. The reduction in diuron concentrations and the increase in DHase activity indicated that the soil microorganisms were capable of degrading the ureic herbicide. Treatment with vermicompost and diuron had a stimulatory effect on soil microbial activity. On the whole, the application of diuron and urea to the vermicompost-amended soil raised DHase and urease activity to maximum levels (>3 μg INTF g^?1 h^?1 and >47 μg NH₄⁺ g^?1 h^?1, respectively). The application of urea to the unamended and vermicompost-amended soil decreased diuron persistence from 18.8 and 33 d to 12.5 and 15 d, respectively. Our findings show that although vermicompost additions reduce diuron availability, this boosts diuron degradation when combined with urea. These additions, under different soil management conditions, minimize the bioavailability and persistence of diuron and consequently the risk of leaching and seepage into aquifers. Compared with untreated soils, these types of treated soils could also improve agricultural sustainability and the quality of the environment.