拖拉机电控液压悬挂系统的耕深模糊控制策略

根据拖拉机液压悬挂系统的特点,提出电控液压悬挂系统模糊控制器的设计方法,建立了模糊推理系统。利用Matlab对悬挂系统耕深分别进行了模糊控制和PID控制仿真,研究结果表明,模糊控制策略控制比PID控制更能适用于拖拉机液压悬挂系统。     

哺乳期内仔猪群体间行为关系的研究

试验主要研究了仔猪不同哺乳周期的行为联系。试验分别选择6头经产的民猪、长白猪及其仔猪作为观察对象,研究哺乳期间2猪种间的仔猪交流信息随时间变化的情况及品种间差异。结果表明:随着产后日龄的增加,哺乳期间一系列行为都发生了变化,仔猪间接触的行为会逐渐增加,但哺乳的第2￣3周又会逐渐减弱。     

基于中断控制的CVT电控系统数据采集系统

基于Infineorl SAK C164CI单片机,采用模块化方法,设计开发了CVT电控系统数据采集系统,包括中断控制的转速采集模块、10位精度A／D转换模块和串口通信模块,并对系统进行了台架和实车试验。试验结果证明,系统采集精度高、速度快、可靠性好、调整方便。     

Electronic feed stations for feeding concentrates to pregnant ewes on commercial sheep farms

ABSTRACT

The aim of this study was to investigate the use and capacity of electronic feed stations (EFS) on commercial sheep farms. The study was conducted on four commercial farms and the numbers of pregnant ewes per EFS were 36, 70, 72 and 80, respectively. Each farm was visited once and behavioural observations were carried out. In addition the date and time for both entering and leaving the EFS and the amount of concentrates dispensed at each visit for extracted. The vast majority of the ewes used the EFS regularly. The number of rewarded visits per ewe per day varied from 3.2 to 5.9, whereas the number of unrewarded visits ranged from 6.0 to 21.5 per ewe per day. We conclude that feeding concentrates to groups of pregnant ewes in EFS function satisfactory, but the design of the entrance and exit gate still have to be improved considerably.     

Determination of the botanical origin of honey by sensor fusion of impedance e-tongue and optical spectroscopy

The aim of this study was to discriminate four commercial brands of Portuguese honeys according to their botanical origin by sensor fusion of impedance electronic tongue (e-tongue) and optical spectroscopy (UV–Vis–NIR) assisted by Principal Component Analysis (PCA) and Cluster Analysis (CA). We have also introduced a new technique for variable selection through one-dimensional clustering which proved very useful for data fusion. The results were referenced against standard sample identification by classical melissopalynology analysis. Individual analysis of each technique showed that the e-tongue clearly outperformed the optical techniques. The electronic and optical spectra were fitted to analytical models and the model coefficients were used as new variables for PCA and CA. This approach has improved honey classification by the e-tongue but not by the optical methods. Data from the three techniques was then considered simultaneously. Simple concatenation of all matrices did not improve the classification results. Multi-way PCA (MPCA) proved to be a good option for data fusion yielding 100% classification success. Finally, a variable selection method based on one-dimensional clustering was used to define two new approaches to sensor fusion, and both yielded sample clusters even better defined than using MPCA. In this work we demonstrate for the first time the feasibility of sensor fusion of electronic and optical spectroscopy data and propose a new variable selection method that improved significantly the classification of the samples through multivariate statistical analysis.     

人工味觉系统在茶叶品质评价中的应用进展

综述人工味觉系统在茶叶感官品质评价中的应用进展,主要包括茶类区分、品质相关性分析、品质定量分析等,并提出ATS(Artificial taste systems)在茶汤预处理标准化、传感器稳定性和灵敏度的提高、模式识别技术的开发等方面的发展前景.     

电子鼻在畜禽养殖场中的应用及研究进展

畜禽养殖场产生的恶臭气体是重要的环境污染因子,常规的检测技术如三点臭袋法费时费力,易受人为因素影响; 气相色谱-质谱联用法(GC-MS)耗时较长、耗费较高,不能确定混合气中各物质对恶臭的贡献份额,无法把恶臭结果与感官嗅觉相关联。这两者均不利于快速准确地评价恶臭污染状况。本文介绍了电子鼻的基本原理及其在畜禽养殖场恶臭管理中的应用,总结了国内外电子鼻技术的发展现状,阐明了电子鼻开发过程中的重点内容,并对今后电子鼻的发展趋势做出了预测和展望。     

电子导师制在农科类专业教学中的应用

介绍了电子导师制的内涵,针对农科类专业学习资源短缺、教学方法陈旧、导师严重不足、师生交流困难的问题,提出了电子导师制在农科类专业教学中的应用策略。     

肉鸭胸肌特异挥发性风味物质的鉴定

为了寻找快大型肉鸭和优质小体型肉鸭的主要挥发性风味物质,构建不同品种肉鸭胸肌气味轮廓,探究品种对肉风味的影响。本试验以9周龄北京鸭、连城白鸭、野鸭胸肌为材料,采用固相微萃取-气相色谱-质谱(SPME-GC-MS)联用技术对其进行检测,计算相对气味活度值(ROAV)寻找各品种鸭胸肌中主要挥发性风味物质。运用正交偏最小二乘法判别分析(OPLS-DA)寻找3个品种肉鸭胸肌差异挥发性风味物质。同时结合电子鼻进行检测。通过SPME-GC-MS技术共检测出104种物质,这些化合物主要为醛类、醇类、酮类和呋喃类物质。北京鸭胸肌中挥发性物质中醇类物质最多,占比40.01%,其次是醛类和呋喃。而连城白鸭和野鸭胸肌中挥发性物质占比以醛类最高,其次是呋喃和醇类物质。通过计算ROAV可得,有43种挥发性物质对鸭胸肌风味有贡献,其中,3个品种胸肌共有物质32种。同时,电子鼻可以对3个品种胸肌进行区分。通过分析3个品种鸭胸肌挥发性物质的结果,探索了3个品种鸭胸肌的特征香气标志物。北京鸭的主要风味物质为(E)-2,4-癸二烯醛、壬醛、2-辛烯醛、2-戊基呋喃、1-辛烯-3-酮;连城白鸭的主要风味物质为(E)-2,4-癸二烯醛、壬醛、2-戊基呋喃、2-辛烯醛、己醛;野鸭主要风味物质为壬醛、2-戊基呋喃、正辛醛、己醛。OPLS-DA结果表明,3种鸭肉的主要差异风味物质基本集中在醛类和醇类物质。本研究对3个品种熟制后的鸭胸肌进行挥发性风味物质的检测,为构建不同品种肉鸭胸肌气味轮廓,探究品种对肉风味的影响具有重要的理论意义。     

应用电子鼻鉴别不同绵羊和山羊品种相同部位的羊肉研究

为了开发和利用滩羊这一独特的地方品种资源,保护宁夏滩羊肉的品牌和维护消费者的合法权益,使用电子鼻对滩羊、小尾寒羊和山羊的背最长肌、后腿肌肉和胸部肌肉的挥发性物质进行了测定,采用主成分分析(PCA)、传感器贡献率分析(Loadings)、线性分析(LDA)3种方法进行区别分析。结果表明:利用电子鼻可明显区分3个品种羊的胸部肌肉和背最长肌,而胸部肌肉PCA分析区分率达到了1.0,表明胸部肌肉可以实现完全区分。