基于模糊推理的芒果病虫害诊断系统研究

为了满足实际病虫害诊断对专家系统的需求,根据芒果病虫害特征诊断与防治的特点,结合芒果病虫害的相关信息,基于案例模糊推理的推理机制和结构框架,以VS2008和SQL Server 2000为开发工具,建立了芒果病虫害诊断系统的知识库规则库和案例库,并设计了推理机制,通过专家系统技术和计算机技术构建了面向农户的数字化芒果病虫害诊断系统。系统的实施对于推广植保知识、指导农户科学防治芒果病虫害有一定的现实意义。     

基于框架表示的玉米病虫草害诊治专家系统的构建及实现

由于农业生产的复杂性,玉米病虫草害的诊断对于农业技术人员经验的依赖很大。而玉米病虫草害诊断专家系统可以将这一复杂的工作变得更有成效。针对传统专家系统知识获取的“瓶颈”问题,在对玉米病虫草害症状框架描述的基础上,利用知识工程方法和技术,结合不确定性推理、匹配冲突消解策略和多媒体技术,实现了基于框架表示的玉米病虫草害诊治专家系统,用于模仿该领域专家思维,补充或代替农业专家指导玉米生产。本文主要阐述该系统的总体结构、知识表示、推理机制和系统实现与应用等方面问题。     

山西省玉米病虫草害发生及农药使用现状

对山西省旱作玉米16个县(区)40个种植大户和8个合作社107分散农户进行157次农户玉米生产现状及用药情况进行调研。结果表明,山西旱作玉米主要病害11种,主要害虫13种,杂草30种。玉米整个生育期化学农药投入制剂量为7.5～22.5 kg/hm~2,年平均用药次数2.5次。玉米覆膜栽培田用药量显著低于不覆膜田,种植大户/合作社用药量大于分散农户。主栽玉米品种感大斑病是杀菌剂用量增加的原因之一。提出推广应用抗病品种、应用黑色地膜除草、做好偶然害虫发生规律与测报,实施在防治指标指导下的适时科学防控。     

图像处理技术在玉米株型上的应用研究

利用图像处理技术,通过对整株玉米图像进行处理和分析,获取图像特征,建立其与实测数据的数学模型,应用所建模型可以找到玉米图像特征值与植株株型的一些农艺性状的定量化联系,为传统田间试验提供了简单易操作的方法,并为探索实行精确化农业寻找思路。     

玉米条带耕作密植高产技术应用效果评价——基于示范户与非示范户的连续跟踪数据

利用辽宁省铁岭市蔡牛镇玉米生产农户2018～2019年连续跟踪实地调研数据,对春玉米条带耕作密植高产技术的应用经济效果进行分析,并基于随机前沿生产函数模型对农户玉米生产的技术效率进行评价。研究表明,种粮大户、合作社等有较大生产规模、农业收入占家庭总收入比重大、户主受教育程度较高的农户更倾向于应用技术,普通农户应用技术比例较低。不论是灾害年还是正常年,春玉米条带耕作密植高产技术显著提高了玉米生产农户的经济效益和技术效率,与正常年份比,在灾害年份更能发挥提高经济效益、技术效率的优势。政府应加大对该技术的宣传力度,提高农民专业素质,鼓励农户规模化经营,加大技术补贴力度,以提高春玉米条带耕作密植高产技术的应用。     

农业产业化地区玉米生产技术效率研究

运用两阶段双重自助抽样DEA方法研究农业产业化地区玉米生产技术效率,研究结果表明,72.6%的农户玉米生产技术效率值处于无效区间,在影响农户玉米生产技术效率的因素中,农户投资规模对玉米生产技术效率具有负效应,表明农户玉米生产投资已进入无效率区间,进一步提高投资规模,已不能提升农户玉米生产技术效率。此外,政府给予玉米种植补贴对玉米生产技术效率的提高并不显著。     

玉米抗病遗传育种的研究进展

几个遗传基础有限的玉米自交系在生产上大面积推广,而进行品种更换是玉米病害有规律发生和流行的重要原因之一。尽管我国在抗源鉴定、抗病遗传以及抗病育种的理论和实践上取得了令人瞩目的成就,在生产上玉米大斑病、玉米小斑病、玉米丝黑穗病和玉米青枯病得到控制和缓解,但是取材、育种方法、种质资源以及基础理论研究等方面的问题仍然十分突出。把长期的种质资源拓宽与近期的抗病育种工作结合起来,才能有效地防止玉米病害的发生和流行。     

玉米条纹病毒的快速鉴定

玉米条纹病发生于世界低洼潮湿的热带和亚热带地区。它是南佛罗里达严重玉米病害中的主要病害。玉米条纹病的几种症状与其它玉米病原体引起的症状相似。有人试图找到病原体,但未能成功。关于病原物玉米条纹病毒(MStpV)特性,报道的结果各不相同。Storey 首先在东非描述了这种病害,认为有两种症状类型,即玉米叶上的宽条纹和窄条纹。Kulkarani 认为这两种症状属于不同病害,将玉米条纹病的名称留给宽条纹类型。两种病害的病原体都由玉米短头飞虱(Pereg-rinus maidis)传播。     

不同规模农户玉米储存损失及其主要影响因素

根据23省(区、市)1196户农户的调查数据,在测算不同规模农户玉米储存损失的基础上,运用Fractional Logit模型研究不同规模农户玉米储存损失原因及其差异。结果表明,随着规模增加,农户玉米储存损失率呈现先下降后上升的趋势,中规模农户的玉米储存损失率最低。实证分析结果表明,不同规模农户玉米储存损失影响因素有相似之处也存有差异。扩大农户玉米储存规模、采用先进的玉米储存设施均能降低不同规模农户的玉米储存损失;鼠害会增加大中规模农户的玉米储存损失。相比于其他措施,物理防治与大小规模农户玉米储存损失正相关,说明大小规模农户大多在损失出现后才采取事后控制措施;扩大经营规模会增加大小规模农户玉米储存损失;品种与大中规模农户的玉米储存损失正相关。     

玉米灰斑病菌人工接种方法

玉米灰斑病是严重威胁玉米生产的叶部病害。采用喷雾、菌液灌心、高粱粒灌心、注射4种方法进行接种,以探索抗病资源鉴定中更为简便、易行、可靠的田间人工接种方法。对玉米叶部病害喷雾是常用的接种方法,对玉米灰斑病菌高粱粒灌心方法不但有利于保湿,而且便于操作,是抗性鉴定时的首选方法。在植株11～12叶期(喇叭口期)应用高粱粒灌心的接种方法,可获得理想的寄主发病效果。     

基于计算机色度学原理的直链淀粉检测系统开发

 基于所提出的CCMA直链淀粉检测方法，利用Microsoft C++工具，开发了一套直链淀粉含量检测系统，它可以完成稻谷直链淀粉含量的测定，并可根据稻谷种类和所执行的标准自动输出样品所属的等级，具有速度快、自动化程度高的特点。与现行国标规定的方法相比，检测结果具有较高的一致性，实现了图像处理技术在谷物二次性质量指标检测中的应用，满足了流通领域中直链淀粉检测的需要。     

新建科研院所必须尽快建立并完善规章制度

阐述了新建科研院所的特点，由此引出必须尽快建立一套规章制度并加强制度宣传，然后分析了按章办事的重要性；并对如何完善规章制度提出了建议。     

Errors related to image analysis technique applied for the investigation of textile local deformations

Due to the woven structure textile materials have excellent formability properties but their behaviour is difficult to investigate. Digital image analysis as non-disturbing and low cost method for the textile investigations has paid a lot of attention, still this method has some limits. The aim of the research is to analyse the accuracy and reliability of the method based on digital image analysis for the textile local deformations investigation and to determine the measurement errors. Depending on the results of experiments when input image acquisition parameters (capture distance d _i and lighting angle γ _j ) were changed the image analysis system was composed. To estimate the measurement errors of the method the scanned image was used as reference sample and parameters of each grid point A ₀, h ₀ ir b ₀ were compared calculating the measurement error depending on image resolution δ _Ai and illumination conditions δ _h60, δ _w60, δ _A60. Image quality evaluation while investigating different material types has shown that image analysis method can be applied for the fabrics the colour intensity of which differs, however it is necessary to ensure sufficient contrast of input image and to apply additional image processing operations.     

Training reduced subjectivity of comparative yield method of estimation of grassland biomass

Measuring grassland biomass using objective, quick and accurate methods is important for practical purposes in agriculture and ecology. Most existing techniques are either expensive or require advanced technical skills making them unaffordable and impractical for farmers in developing countries. The comparative yield method is a quick technique that involves the estimation of grassland biomass from visual scores. Despite its potential for use by farmers with minimal technical skills, it has been criticized for being subjective, thus limiting its use for research purposes only. We hypothesized that training and establishment of agreed‐upon ground rules can reduce this subjectivity. We compared data collected by 36 farmers in northern Ethiopia, who participated under three instruction groups. Group 1 was involved both in the selection of reference plots and calibration plots and agreed‐on ground rules. Group 2 was shown the reference plots and orientated about the ground rules. Group 3 was neither shown reference plots nor orientated on ground rules. Levene's test for equality of variance was performed among the estimations made by individuals. Mean values of scores and biomass measurements varied among groups. The variability of records was higher in groups 3 and 2 than in group 1, indicating the need for training and agreed‐upon ground rules to achieve objectivity. We conclude that with minimal training and agreement on ground rules, the comparative yield method can be used by farmers and ecologists in developing countries to estimate grassland biomass with better precision and accuracy.     

Intelligence control of on-line dynamic gray cloth inspecting machine system module design. I. Tension controller design

Tension is very closely related with fabric inspection quality, as not well controlled tension of gray cloth will lead to stretch, relax or fold of gray cloth, so that no sharpest image can be taken. Now that gray cloth tension and convey speed are related with taking sharp image, so this study attempts to design a gray cloth tension control module, develop the intelligent online dynamic gray cloth defect automatic detection system. Gray cloth tension control module makes direct regulation of structural tension of feed and wind rolls and conveys speed control module by load cell coupled with A/D, D/A signal conversion and two sets of inverters. This study utilized fuzzy control theory to design controller so as to keep surface tension consistency of gray cloth, improve recognition rate of gray cloth defect, so that the system can have high action efficiency. In previous fuzzy controller designs, membership functions were often designed by means of trial-and-error method, which usually cost much time. This study used Taguchi method to make membership function programming, and made main effect analysis to choose a group of optimal membership function combination. Through systematized, efficient experimental design, tension controller designed in this study could stabilize gray cloth tension very soon, and acquire sharp gray cloth image.     

2019版《有机产品》国家标准及《有机产品认证实施规则》中有机茶认证要点解析

国家标准《有机产品生产、加工、标识与管理体系要求》(GB/T 19630-2019)(以下简称2019版有机标准)已于2020年1月1日开始实施。同时,《有机产品认证实施规则》(以下简称2019版实施规则)和《有机产品认证目录》也有更新。本文针对以上法律法规中涉及到有机茶生产管理过程中需要关注的几个要点进行剖析,便于各有机茶生产企业和认证机构人员掌握新旧法规中的异同,在生产和认证中适应新制度的要求。     

茶树叶片精准测色装置构建及在稀有种质鉴别中的应用

采用扫描仪、测色器Color Pix和RGB颜色系统建立测色装置,并利用在线工具Color Hexa将色差指标值转换成CIELab颜色体系参数,对绿、黄、紫色系典型茶树种质进行环向和径向测色法比较分析。结果表明,径向测定法采用单叶多点重复取值与环向测定法中环位取值具有相近叶色表征作用。通过对120个不同叶色种质的径向多点位重复测定和环向中环位测定,2种方法的明度L*、色差指标值a*和b*显著正相关。但是,考虑到使用的简便性与分析效率,提出用环向中环位测定值定义叶色更为合适。对上述120个供试茶树种质的环向中环位叶色测定值构成的三维散点图进行分析,发现能够将紫红色种质与紫色系种质有效分离,更进一步证明该技术在特异叶色种质精准鉴别中具有实用价值。     

Manufacturing of twisted continuous PAN nanofiber yarn by electrospinning process

The development of a modified method to produce heat treated twisted nanofibrous yarns using two oppositely metallic spinnerets system is presented. This method allows the production of more uniform, stronger twisted poly acrylonitrile (PAN) yarns. The novelty of this system permits for in-situ heat treating of the nanofiber yarns. The average diameter of twisted nanofiber yarns is 340.65 μm with 5.8 CV%. The values of the initial modulus and stress of heat treated yarns increase from 1.90 GPa and 61.30 MPa in untreated one to 4.51 GPa and 116.56 MPa, respectively. In order to quantify the alignment of the nanofibers Fourier power spectrum (FPS) and image analysis were used. So the treated yarn shows more degree of nanofiber alignments than the untreated one.