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31.
基于Web的亚热带水果产品质量安全追溯系统关键技术研究 总被引:5,自引:0,他引:5
徐龙琴 《计算机工程与设计》2011,32(4):1174-1177,1189
为了实现对亚热带水果"从果园到餐桌"全方位的跟踪和追溯,分析了水果产品生产流程并确定了影响其质量的关键点,以产品生产批次作为"身份标识",采用UCC/EAN-128编码方式结合流程编码、RFID和二维码等编码技术进行了追溯编码,并采用任务与角色相结合的权限分配策略,构建了一个多层次多用户权限动态管理的亚热带水果生产加工全过程的质量跟踪与追溯系统,为生产者、质检部门和消费者提供一个集产品生产加工诸环节的信息交流平台,并以网络、语音、短信、触摸屏向公众提供追溯查询和防伪服务,具有应用推广价值。 相似文献
32.
本文提出一种基于细菌迁徙的自适应果蝇算法(CAFOABM),用于求解净化除钴过程锌粉添加量优化设定问题.首先从净化除钴的反应机理出发,通过引入除钴率建立锌粉添加量与氧化还原电位值、出口钴离子浓度间带约束的非线性优化设定模型;为了避免果蝇算法在迭代寻优过程中出现停滞现象,CAFOABM引入多种群并行搜索策略和改进搜索算子对搜索状态的转移规则进行改进;并采用区分可行解与不可行解法进行约束处理,保留一定比例的不可行解个体,有效避免了有用解信息的丢失.实际生产数据验证结果表明,CAFOABM算法优化设定的锌粉添加量与人工操作的经验数据相比减少7.83%,出口钴离子浓度满足实际生产要求且趋于平稳. 相似文献
33.
Liquid chromatography coupled to mass spectrometry (LC-MS) is an excellent technique to determine trace levels of polar and thermolabile pesticides and their degradation products in complex matrices. LC-MS can be equipped with several mass analyzers, each of which provides unique features capable to identify, quantify, and resolve ambiguities by selecting appropriate ionization and acquisition parameters. We discuss in this review the use of LC coupled to (quadrupole) time-of-flight mass spectrometry (LC-(Q)ToF-MS) to determine the presence of target and non-target pesticides in water and food. This technique is characterized by operating at a resolving power of 10,000 or more. Therefore, it gives accurate masses for both parent and fragment ions and enables the measurement of the elemental formula of a compound achieving compound identification. In addition, the combination of quadrupole-ToF permits tandem mass spectrometry, provides more structural information, and enhances selectivity. The purpose of this article is to provide an overview on the state of art and applicability of liquid chromatography time-of-flight mass spectrometry (LC-ToF-MS), and liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS) for the analysis of pesticides in environmental matrices and food. The performance of such techniques is depicted in terms of accurate mass measurement, fragmentation, and selectivity. The final section is devoted to describing the applicability of LC-(Q)ToF-MS to routine analysis of pesticides in food matrices, indicating those operational conditions and criteria used to screen, quantify, and identify target and "suspected" pesticides and their degradation products in water, fruits, and vegetables. The potential and future trends as well as limitations of LC-(Q)ToF-MS for pesticide monitoring are highlighted. 相似文献
34.
35.
W. P. Ponce J. L. Nation T. C. Emmel B. J. Smittle P. E. A. Teal 《Journal of chemical ecology》1993,19(12):3045-3056
Pheromonal volatiles emitted by irradiated and control 5- to 11-day-old Caribbean fruit flies,Anastrepha suspensa (Loew), were collected on Tenax adsorbent filters and quantified by gas chromatography (GC). The components released were identified by comparison of retention times on GC and by mass spectrometry (MS) with authentic synthetic standards. Pharate adults were irradiated with gamma rays from a60Co source at a dose rate of 10.3 Gray (Gy)/min. The total dosages given were 30, 50, 70, and 100 Gy. Pheromone volatiles were collected from adult males when they were between 5 and 11 days of age. The compounds quantified were (Z)-3-nonenol and (Z, Z)-3,6-nonadienol, which eluted from the GC column together and were quantified as one peak,-bisabolene, suspensolide, anastrephin, and epianastrephin. Irradiation with 30 Gy did not significantly reduce any pheromonal components, nor did it change the pheromonal blend. In contrast, suspensolide and bisabolene were significantly reduced in flies irradiated with 50 Gy, while the nonenols and epianastrephin were reduced at the 70-Gy dose. Irradiation with the 100-Gy dose reduced all components with the exception of suspensolide.University of Florida Agric. Exper. Sta. Journal Series No.R-03156. 相似文献
36.
为解决农作物病虫害的诊断问题,选择京郊常见果树的三种害虫:桃蛀螟成虫、华北大黑鳃金龟成虫、桃六点天蛾,使用计算机视觉技术清除背景,获取该害虫的形状参数、偏心率等形态特征。通过判别分析,建立三种害虫形态特征的判别评分函数,并测试了该判别评分函数的有效性。实验结果表明,形状参数、偏心率、似圆度特征能反映这三种害虫的形态特点,可有效区分这三种害虫。 相似文献
37.
分光光度法快速测定蔬菜水果中VC的含量 总被引:2,自引:0,他引:2
通过吸收光谱曲线法确定VC的水溶液的最大吸收波长为267 nm,进而通过工作曲线法快速测定蔬菜水果中VC的含量,本方法与常规方法比较,具有快速、准确、简便、试剂易得等优点. 相似文献
38.
介绍了科研项目管理的概念,决策立项的意义。以钢铁企业实施重点科研项目的管理为例,对于科研项目过程中的产学研相结合模式的实践、项目管理模式与团队建设探索、协调处理生产与研发的关系、项目成果转化评估等方面进行了探讨。 相似文献
39.
Steptoe Andrew; Perkins-Porras Linda; Rink Elisabeth; Hilton Sean; Cappuccio Francesco P. 《Canadian Metallurgical Quarterly》2004,23(6):574
This study assessed psychological and social factors predicting 12-month changes in fruit and vegetable consumption achieved by 271 men and women from a low-income population randomized to brief behavioral and nutrition education counseling. Greater increases in fruit and vegetable intake were achieved in the behavioral than in the nutrition education condition (1.49 vs. 0.87 portions per day, p=.021). Increases were predicted by baseline social support for dietary change but not by baseline psychological measures. However, short-term (8-week) changes in dietary self-efficacy, encouragement, anticipated regret, perceived benefits, and knowledge of recommended intake predicted 12-month changes in fruit and vegetable consumption independently of gender, age, ethnicity, income, and baseline intake. These factors accounted for 51% of the superiority of behavioral counseling over nutrition education. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
40.