树苗自动嫁接机砧木切削机构研究

使用树苗自动化嫁接机能实现优质苗木的快速繁育,砧木切削机构是其重要子系统,为实现树苗嫁接砧木自动化切削,通过对树苗自动化嫁接技术要求的分析,采用劈接的嫁接方法,设计了能实现自动对中、定位、固定、切削、退刀的用于树苗自动嫁接机的砧木切削机构,分析了该机构的工作流程,确定了砧木切刀形状尺寸参数、撑砧块和压砧块的形状尺寸参数以及各部分位置关系尺寸参数,经过样机试验表明,该机构在树苗自动嫁接机系统中运行稳定.     

X射线成像技术判别蚕茧性别

为了实现雌、雄蚕茧分开缫丝,该文提出了一种基于X射线成像技术的蚕茧性别判别方法。利用X射线成像装置获取蚕蛹图像,对蚕蛹图像预处理并提取7个形状特征后,分别采用线性判别分析(LDA)和BP人工神经网络(BPANN)建立判别模型。结果表明同一品种同一时期、同一品种不同时期、不同品种同一时期蚕茧的LDA判别模型性能优于BPANN判别模型;LDA模型识别正确率分别大于91.33%、86.73%、89.53%,BPANN模型识别正确率分别大于88.47%、81.97%、83.26%,且LDA模型判别时间(68.5 ms)远低于BPANN模型(503.6 ms)。研究结果可为蚕茧性别在线检测提供技术指导。     

人工喂入式鲜食甜玉米籽粒切脱机的研制

该文介绍了一种采用在玉米籽粒根部切削方式将甜玉米果穗上的籽粒与玉米芯分离的机械设备的设计。该设备在籽粒切脱过程中刀片与玉米籽粒根部（玉米芯外缘）成弹性浮动接触，可随玉米果穗直径的不同而做自动调整，保证刀片刃部始终贴近玉米籽粒根部切削。特点是效率高、切粒质量好，适应甜玉米籽粒含水率在58%～75％范围内，既适合甜玉米籽粒切脱、也适合糯玉米籽粒切脱。满足了中国鲜食甜玉米深加工的需求。该设备采用刀片高速转动、玉米果穗直线运动旋划切削技术。经过对该设备设计、试制、试验结果表明，完全适合甜玉米切脱籽粒。     

果蔬三维切丁机设计与试验

为了提高国产切丁机的切削质量和切削效率,设计了一种新型果蔬切丁机.该机采用旋转推进器送料,离心切削法切片,圆盘格栅刀切丝,最后由切丁条刀切丁的三维切丁技术.论文阐述了切丁机结构组成及工作原理,并以马铃薯为切削对象,进行了物料在离心切削滚筒内的受力分析计算,确定出切削滚筒最小工作转速为133.3 r/min;对所切物料丁断面曲线方程分析,得出切丁断面具有3种不同形状,通过比较不同离心切削滚筒与切丁条刀转速比条件下的切丁断面形状及偏差,得出其最佳速比为0.17.样机切削性能试验表明:切出的15 mm× 15 mm×15 mm和20 mm×20 mm×20 mm马铃薯立方块形状规整,其相对偏差分别为11.7％、12.7％,均小于15％,达到了预期目标,为新型果蔬三维切丁机的研制提供了参考.     

基于亚塑性本构模型的土壤-触土部件SPH互作模型

触土部件是农机的主要组成部分,高精度的土壤-触土部件互作模型对农业耕作触土部件的节能优化设计具有重大意义。为提高土壤切削过程数值模拟的精确度,该研究基于光滑粒子流体动力学（Smoothed Particle Hydrodynamics,SPH）框架,从土壤亚塑性本构模型出发,结合土壤-触土部件接触模型,提出一种土壤-触土部件互作模型。通过砂土坍塌试验和土壤切削试验,对比分析了模拟仿真和物理试验中砂土自由表面演变、内部应力变化、土壤静止和运动分界面形态以及粒子位移。在此基础上对4种不同形状刀具的土壤切削过程进行模拟,以土壤切应力、位移分布表征刀具在切削过程中对土壤的破坏情况,讨论了大半径抛物线型刀具切削过程中的土壤粒子速度场,并得出不同形状刀具切削阻力的变化规律。结果表明,刀具水平切削阻力的模拟值和试验值平均相对误差为9.885%,说明所提模型对刀具水平切削阻力的预测精度较高。研究结果可为土壤-触土部件互作模型的建立提供新的思路,为触土部件的优化设计提供参考。     

基于机器视觉的多个玉米籽粒胚部特征检测

为了利用机器视觉进行多个玉米种子品种的自动识别,该文提出了一种针对多个玉米籽粒进行胚部检测的方法。该方法基于阈值分割和形态学,在RGB空间,采用自动屏蔽0值像素的大津法（Otsu法）,根据B分量值对多粒玉米籽粒扫描图像进行分割,并采用改进的开闭运算对分割后的图像进行修整,最终得到多个玉米籽粒胚部区域。以4个黄玉米品种各45个籽粒为实验对象,以此方法进行胚部检测,为了验证所得胚部区域有效,提取胚部区域面积、周长分别与手工测量的面积、周长进行线性回归分析,R2的均值分别达到0.9834、0.9578;进一步提取所得胚部区域的形状参数,进行聚类识别,不同品种间的差距值反映了不同品种胚部视觉效果上的差异大小,4个品种中1种识别率为97.8%,其余3种均为100%;多个玉米胚部检测较每个籽粒单独处理的效率提高了29.59%。试验结果表明本文提出的多个玉米籽粒胚部检测方法可行。此研究结果为进一步研究玉米籽粒的胚部特征提供了有利条件,也为实现玉米品种的快速准确分类提供了参考。     

基于解模糊算法的蚕蛹图像恢复及雌雄识别

在利用机器视觉技术识别雌雄蚕蛹过程中,因蛹体为非规则椭球体所带来的空间变化模糊造成蚕蛹图像中大量细节结构特征信息丢失,这极大地降低了雌雄蚕蛹识别的准确率。针对此问题,该文提出了一种将复杂的空间变化模糊图像恢复问题化为多个简单的空间模糊图像求解的策略。首先根据蚕蛹图像的模糊图谱将图像划分为多个具有相似程度模糊的子图像区域;再利用 Lucy Richardson 方法对各子图像区域分别进行非盲反卷积解模糊;最后将恢复的各子图像进行拼合并使用双边滤波方法消除图像拼合误差,保证图像信息准确融合。试验结果表明,该算法性能与目前所公认最优的 Shen 方法相比,能够得到更好的蚕蛹图像视觉质量,蚕蛹图像质量的定量评估指标——总变差均值（TVM）平均提高了22.8%,因此,该文方法具有更优的性能,能够有效消除空间变化模糊影响,恢复出更多的蚕蛹图像细节结构特征。利用基于霍夫变换理论的形状匹配算法对处理前和处理后的400颗蚕蛹成像图像进行了雌雄识别试验研究,试验结果表明,相对于原始未处理的蚕蛹图像,经该文方法处理后的蚕蛹图像,雌雄蚕蛹识别率提高了40.5百分点。该文方法对西葫芦、南瓜等类非规则椭球体果蔬图像也能够进行有效的图像质量改善,这充分显示了该文方法的广泛适应性。     

基于拟脑智能系统的烤烟烟叶分级研究

对烟叶进行检测与分级是控制烟叶质量的重要手段之一.研究烟叶质量的合理表征参数及其自动提取方法,以及烟叶辅助分级系统,是迫切需要解决的问题.应用人工智能方法和计算机技术进行烤烟烟叶自动分级,提出一种借鉴生物脑信息处理结构的烤烟烟叶智能分级系统.该系统由思维模型、感觉模型和行为模型3个子系统构成,分别模拟分级专家的思维智能、感知智能和行为智能,具有学习与记忆、判断与模糊推理、分级决策等多种思维功能,以及图像自动采集、上下位机通信等协调与控制功能.应用该系统进行烟叶分级试验的结果与分级专家分级结果的平均一致率可达到85%,与人工分级水平相当.     

苗木嫁接机器人切削机构模拟试验

为研究满足苗木嫁接机要求的切削机构,设计了半旋转切削机构并优化其结构参数.选取桃、李、柑橘、葡萄和板栗五种嫁接幼苗作为试验对象,在模拟切削试验装置上进行了切削模拟试验.试验结果检验该半旋转切削机构的可行性及分析得出了影响切削阻力试验指标和切削成功率试验指标的主、次试验因素.研究表明影响苗木切削的因素:苗木平均直径、转速、滑切角分别与切削阻力和切削成功率的相关性.综合得出,该半旋转切削机构是可行的;苗木直径、转速和滑切角分别较大地影响切削阻力和切削成功率,苗木直径是主要影响因素,实行工厂化育苗来有效保证苗木直径大小和均匀性;转速调节范围50～60 r/min,滑切角调整略人于30°.     

可移动水土流失实验室系统的原理及特点

可移动水土流失实验系统使固定的野外径流小区坡面侵蚀观测转变为车载流动试验观测.实践结果表明,该系统可实时对不同坡度的小区进行人工降雨模拟实验,分析侵蚀土壤理化性质和坡面侵蚀过程,极大地提高了水土流失观测的速度和效率.系统中液压自动升降坡面侵蚀土槽可根据试验要求稳定变化,且坡度可在0°～30°之间任意调整,加快了数据采集速度,缩短了试验周期,数据采集更加方便.针对长江流域土壤侵蚀特点对传统试验土槽做了改进,增加了壤中流收集装置,使得坡面侵蚀试验装置更趋合理.人工模拟降雨试验喷头模拟的雨强范围也明显增加,可在20～170 mm/h之间任意调整.     

中国长江中下游地区桑叶-蚕茧系统硫素转化效率

Cocoon samples were collected from fifty-two mulberry gardens with high, intermediate, and low silkworm cocoon productivities in the lower-middle reaches of the Yangtze River in the six China’s provinces of Jiangsu, Jiangxi, Anhui, Fujian, Hunan, and Hubei to determine the transformation efficiency of S from mulberry leaves to silkworm cocoons, and to evaluate the sulfur cycle (uptake and output) in the mulberry leaf-silkworm cocoon system with typical mulberry gardens in the lower-middle reaches of the Yangtze River in China. The transformation efficiency of sulfur (TES) from mulberry leaves into silkworm cocoons in the high-productivity mulberry gardens was significantly lower (P < 0.05) than that in the low-productivity gardens. For the high-productivity mulberry gardens the TES from mulberry leaves into the cocoon shell was significantly higher (P < 0.05) than that for low-yield mulberry gardens. Producing 1 kg dry cocoon in mulberry gardens required uptake of about 20 g S, however 1 kg of dry cocoon only removed about 4 g S. Therefore, recycling of these organic wastes with silkworm cultivation was important for sulfur balances.     

稳定同位素指纹分析在蚕茧产地溯源中的应用研究

蚕茧产地溯源是丝绸原产地溯源的基础.本研究为了探究蚕茧产地溯源最适方法,以不同产地的蚕茧为研究对象,利用不同产区蚕茧的13C、15N、18O和2H同位素组成,通过单因素方差分析、多重比较分析、Fisher线性判别分析留一法交叉验证,最后建立蚕茧产地溯源模型.单因素方差分析结果表明,不同产地蚕茧的δ13C、δ15N、δ1...     

广西桑蚕茧丝质量与性能指标的测定分析

本研究对广西桑蚕茧的茧丝质量与性能指标进行了测定分析。结果表明,广西桑蚕茧外形略小,茧层丝胶含量、茧层易溶丝胶含量、丝胶溶解性以及茧丝纤度等主要指标均与江浙夏秋用桑蚕茧有明显差异。桑蚕茧的茧层丝胶含量、易溶丝胶含量随庄口、季节不同而有显著差异;春季桂南地区的蚕茧茧层丝胶含量高于桂西北地区,秋季刚好相反。茧层易溶丝胶含量在11.6%-14.4%之间,约占丝胶总含量的41%~45%,茧层易溶丝胶含量和解舒率呈显著的正相关关系,即茧层易溶丝胶含量越多,蚕茧解舒越好。庄口和季节是影响桑蚕茧层易溶丝胶含量高低与蚕茧解舒优劣的重要因素。广西桑蚕茧层丝胶对煮茧温度更敏感,茧丝纤度粗细变化开差大。因此,我们认为目前困扰广西桑蚕茧加工技术突破的原因之一是缫丝工艺技术,采用传统缫丝工艺技术难以正常发挥广西桑蚕茧的茧丝优势与特性。     

Suitable characters for selective breeding in Eisenia fetida (Oligochaeta)

Selective breeding of invertebrates has been suggested by many but studied by few. The possibilities of improving characters like biomass, maturation time, coccoon production rate, and hatching success of cocoons for the earthworm Eisenia fetida were examined in the present study. The results showed that biomass, maturation time, and number of hatchlings could be successfully improved by selective breeding, although a concomitant tendency to a lower reproductive rate, as found in vertebrates, was observed. Other characters like cocoon production rate, hatching success, and number of hatchlings per cocoon also showed promising results.     

育种用玉米种子切片取样自动定向方法与试验

为解决玉米育种激光切片取样机器人设计中玉米种子自动定向问题,该文提出了一种计算机视觉与姿态调整装置相结合的定向方法,并使用此方法做了验证试验。使用MATLAB神经网络模式识别工具箱,以种子的部分特征参数作为神经网络的输入,以预定义的种子形态和姿态为输出,建立模型并对模型进行训练,训练完成的模型用于种子姿态识别,姿态调整装置根据识别结果将种子调整到理想姿态。对497组样本进行训练,得到形态识别准确率97.8%,姿态识别准确率99.8%,识别速度1.3 s/幅,能满足设备的设计要求,验证了姿态识别方法的准确性和姿态调整装置设计的合理性。该方法可为玉米种子自动定向问题提供解决方案,为自动育苗机中自动定向装置的设计提供参考。     

蚕品种对不同发育阶段蚕体、蚕沙及蚕茧稳定同位素特征的影响

丝绸具有重要的经济与文化价值。为探究桑蚕品种对丝绸产地溯源模型准确率的影响,本研究通过桑蚕饲养试验,采用单因素方差分析(one-way ANOVA)和椭圆联合置信区间(EJCR)测试探讨桑蚕从幼虫至吐丝结茧的不同发育阶段蚕体、蚕沙样本中4种稳定同位素比值(δ¹³C、δ¹⁵N、δ²H、δ¹⁸O)的变化趋势,并比较不同品种对稳定同位素比值的影响。结果表明,不同龄期蚕体的δ¹³C、δ¹⁵N、δ²H和δ¹⁸O值变化趋势不同,且不同龄期蚕沙的稳定同位素比值变化趋势与蚕体相似。单因素方差分析结果表明,在相同饲喂条件下,除少数龄期外,不同品种之间蚕体和蚕沙样本稳定同位素组成总体不存在显著差异,且蚕体和蚕沙样本的δ¹³C、δ¹⁵N、δ²H相关性较强。桑蚕品种可能导致蚕茧中单个稳定同位素出现较大变化,对δ¹³C、δ¹⁸O影...     

Effects of BmKIT 3 R gene transfer on pupal development of Bombyx mori Linnaeus using a Gal4/UAS binary transgenic system

The pupal stage of the silkworm Bombyx mori Linnaeus lasts for approximately two weeks. However, prolongation of pupal duration would reduce the labor required to process and dry fresh cocoons. This study investigated the effects of BmKIT(3)(R) gene (from the Chinese scorpion Buthus martensii Karsch) transfer on the pupal development of B. mori using a Gal4/UAS binary transgenic system. Gal4 driven by a pupa-specific promoter BmWCP4 (from a B. mori wing-cuticle protein gene) or PDP (from a B. mori cocoonase gene), and BmKIT(3)(R) driven by a UAS cis-acting element were used to construct novel piggyBac-derived plasmids containing a neomycin-resistance gene (neo) controlled by the Bombyx mori nucleopolyhedrovirus (BmNPV) ie-1 (immediate-early gene) promoter and a green fluorescent protein gene (gfp) under the control of the B. mori actin 3 (A3) promoter. The vector was transferred into silkworm eggs by sperm-mediated gene transfer. Transgenic silkworms were produced after screening for neo and gfp genes, and gene transfer was verified by polymerase chain reaction and dot-blot hybridization. The larval development of the hybrid progeny of Gal4- and UAS-transgenic silkworms was similar to that of normal silkworms, but some pupae failed to metamorphose into moths, and the development of surviving pupae was arrested as a result of BmKIT(3)(R) expression. Moreover, Gal4 driven by the BmWCP4 promoter delayed pupal development more effectively than that driven by the PDP promoter in the Gal4/UAS binary transgenic system. Pupal durations of hybrid transgenic silkworm progeny with BmWCP4 and PDP promoters were approximately 5, 2, and 4 days longer, respectively, compared to corresponding normal silkworms, BmWCP4/Gal4, and UAS/BmKIT(3)(R) transgenic silkworms, respectively. These results suggest new avenues of research for prolonging the pupal duration of silkworms.     

家蚕育种个体、蛾区自动称量与选择系统

为提高家蚕育种效率，满足家蚕育种工作者要求，利用Visual Basic 6.0 for Windows开发设计了家蚕育种个体、蛾区自动称量与选择系统。该系统通过串行接口采用零Modem连接方式将两台电子天平与计算机相连接，通过MSComm通讯控件实现对蚕茧个体、蛾区称量数据的自动采集，采用Bayes判别函数和聚类分析法自动根据称量结果对蚕茧个体作雌雄识别，采用基于数量遗传理论设计的综合选择指数进行个体选择，并方便地实现称量数据的查询和管理。     

Genetic variation in desiccation tolerance of Dendrobaena octaedra cocoons originating from different climatic regions

The aim of this study was to examine genetic variation in desiccation tolerance in cocoons of the parthenogenetically reproducing earthworm Dendrobaena octaedra by comparing populations originating from different geographic regions (Denmark, Norway and Finland), representing large differences in precipitation and temperature. In one experiment, the tolerance of the three populations to increasing desiccation stress in the range from 100 to 91.6% relative humidity (RH) was examined, aiming to represent ecologically relevant RH values. In a second experiment, the effect of cocoon size on desiccation tolerance was investigated at 92.3% RH in the same three populations. There were highly significant differences in desiccation tolerance between populations, indicating a high genetic differentiation of this trait in D. octaedra. Cocoons from Denmark were much more sensitive (71±14% mortality at 91.6% RH) than cocoons from Norway (21±4% mortality) and Finland (4±5% mortality). Cocoons of worms from Finland and Norway were significantly larger than cocoons produced by worms from Denmark suggesting that cocoons from Denmark lost water at a higher rate when subjected to low humidity. Assuming that slow dehydration is necessary for physiologically based protection mechanisms it may be expected that desiccation tolerance is positively correlated with cocoon size. However, within each of the populations cocoon fresh weight did not have any significant impact on desiccation tolerance. When all populations were pooled there was a significant positive effect of cocoon fresh weight on desiccation tolerance, explaining about 20% of the total variation (linear regression). It seems therefore that genetic variation of desiccation tolerance in D. octaedra cocoons is related to variation in both cocoon size and other, physiologically based tolerance mechanisms.