基于项目多样性的农业机械化评价方法

农业机械化涉及因素众多、包含项目多样和地区间存在差异,使得农业机械化评价比一般概念的综合评价更为复杂.依据系统理论与方法,在全面认识农业机械化评价特点的基础上,明确了项目重要性是影响评价结果的因素之一,提出了基于项目多样性农业机械化评价的方法思想与技术路线.讨论了丘陵地区农业机械化所包含类别项目的一般层次结构,建构了农业机械化评价的程度度量和项目相对重要性衡量两套指标体系,阐明了农业机械化程度的计算方法,并在实际中加以应用,得到满意结果.     

基于无线网络的精密播种机监测系统设计

采用PLC技术、数据库技术和无线传输技术设计了一套8行精密播种机的监测系统.系统利用GPRS网络和无线传感器实现了精密播种机工况的无线监测,实现了监测信息的无线实时、快速和可靠传输.采用液晶触摸屏作为人机界面,可方便地显示8行播种工况、播种速度、播种面积和生产率,系统还可实现堵塞报警等功能.监测试验表明,该系统可完成播种工况的监测.     

黑龙江省西部半干旱区大豆水分生产函数试验研究

通过盆栽实验,应用大豆不同灌水处理下的耗水量和产量的试验资料,用Jensen模型、Minhas模型、Blank模型、Singh模型、Stewart模型分别对黑龙江省西部半干旱区大豆的水分生产函数进行了拟合,对模型求解结果进行了比较分析与检验。用生长曲线来拟合水分敏感指数累积函数,计算了不同生育阶段的水分敏感指数。结果表明:加法模型Stewart、乘法模型Jensen优于其它分段计算模型;水分敏感指数累积函数拟合的效果较好。     

R~*树结点的主元分界分裂方法

为降低R*树结点重叠度,提高其空间利用率,通过结点特征点集方差及各子特征点集方差之和建立主元分析和结点分裂之间的联系,基于主元分析算法对特征点集进行降维处理,计算特征点集的主元向量,过特征点集中心且正交于该向量建立分界面对特征点集进行划分,将各簇数据的中心作为结点分裂的初始分裂中心,实现R*树结点分裂。实验证明,该算法具有较高的结点分裂效率,使得R*树结点重叠度降低,分裂结果较合理,显著提高了R*树构造效率和k近邻查询效率。     

多孔管沿程压力分析

针对目前多孔管沿程水头损失计算方法存在的问题,推导出了一个新的多孔管沿程水头损失近似计算公式。利用导出的公式,分析了多孔管沿程的压力变化,这无论是对喷、滴灌工程的规划设计,还是对多孔管水力特性的进一步研究都是有益的。     

连杆式机动水稻插秧机万向联轴系统的运动分析

以 2 ZT-935 型水稻插秧机为例,对不等角速双万向联轴器的输入轴 1与输出轴 3的运动关系进行了深入研究,比较精确地推导出轴1、3与中间轴2的夹角θ_1、θ_3(见图1)随转弯角度β变化的关系式,绘制了轴3的角速度ω_3、角加速度α_3的变化规律曲线图。为分析插秧系统的运动学、动力学问题和插秧质量提供了依据。     

Application of molybdenum fertilizer enhanced quality and production of alfalfa in northern China under non-irrigated conditions

Molybdenum (Mo) is an essential micro-mineral nutrient for plant growth and development. As an important legume forage, alfalfa (Medicago sativa) is frequently planted in marginal lands of northern China where water scarcity and infertile soil are limiting factors for alfalfa production. Mo plays an important role in nitrogen (N) metabolism in general and N fixation in legume species in particular. To evaluate the role of Mo fertilizer in alfalfa quality and production in semi-arid areas of northern China, we conducted a three-year field experiment in Inner Mongolia from 2012 to 2014. Mo fertilizer at the doses of 0, 150 g hm^?2, 300 g hm^?2yr^?1 was applied consecutively across the three years. Application of Mo at 300 g hm^?2yr^?1 significantly increased dry yield of alfalfa in 2014. Crude protein (CP) content of alfalfa without application of Mo exhibited a decline trend from 2012 to 2014. Application of Mo significantly enhanced total CP in 2012 and 2014, and delayed the reduction in total CP across the three years. In contrast to CP, Mo fertilizer had no significant effects on neutral detergent fiber and acid detergent fiber content. In addition, we found that nitrate reductase activity of alfalfa was increased by Mo fertilizer, which may account for the enhanced CP content in alfalfa. These findings highlight that application of Mo fertilizer can be an effective way to improve alfalfa production and quality in semi-arid areas in northern China.     

涕灭威的安全性研究与管理进展

本文简要介绍了涕灭威的活性及其作用机制,详细分析了其在国内外登记管理、食品中涕灭威残留及其风险评估、土壤中涕灭威归趋及其对水体的影响研究进展.     

河南省烟草病毒的小RNA测序检测

To identify viruses in Henan tobacco-planting areas, from 2015 to 2017 and 2019, 288 symptomatic tobacco samples were collected and then subjected to small RNA sequencing. Results showed that at least 7 viruses were detected from these samples which including four previously reported viruses, cucumber mosaic virus (CMV), tobacco mosaic virus (TMV), potato virus Y (PVY) and tobacco vein banding mosaic virus (TVBMV). Other three viruses, wild tomato mosaic virus (WTMV), brassica yellows virus (BrYV), and cycas necrotic stunt virus (CNSV) were firstly detected in Henan province. However, tobacco etch virus (TEV) and tobacco ringspot virus (TRSV) were not detected from these samples. In addition, CMV, TMV, PVY, TVBMV, and BrYV were the dominant viruses infecting tobacco in Henan Province.     

2014年我国农药登记产品的特点和趋势分析

本文分析了2014年我国农药登记产品的特点和趋势,农药登记产品数量下降,正式登记产品趋势增加;杀虫剂产品数量排名第一,杀菌剂占比趋势上升;悬浮剂产品名列首位,剂型优化趋势显著;新农药数量增加稳定,国内研发趋势增强;生物农药稳步发展,农产品安全趋势向好;小作物用药登记取得突破,无药可用趋势下降;专供出口登记停止,分装登记管理趋势加强。