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龙眼表面农药残留的无损检测研究-基于近红外光谱分析 总被引:1,自引:0,他引:1
为进一步探索水果农药残留的快速无损检测技术,利用近红外反射光谱分析技术,对常用的高残留农药敌百虫和敌敌畏在龙眼表面残留的无损检测进行了研究.首先在500~1000nm波段范围内,将采集到的漫反射光谱数据进行主成分分析,利用主成分1和主成分2的得分值对样本进行聚类分析,得到较好的聚类结果;然后用各类样本的主成分得分作为神经网络的输入,建立了三层的BP人工神经网络模型,并进行了农药残留检测.结果表明,对敌百虫农药残留的检测正确率为93%,对敌敌畏农药残留的检测正确率为80%,为水果表面的农药残留快速无损检测探索了一条可能的新途径. 相似文献
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有机磷农药残留快速检测方法研究 总被引:2,自引:1,他引:2
农产品中有机磷农药残留超标问题给食品安全性带来了严重挑战.控制农药残留最为有效的方法之一是加强农药残留检测的力度.为此,在对当前农药残留的检测方法进行调查研究和分析的基础上,利用氯化钯与含硫基有机磷农药的显色机理,研究了甲胺磷、乐果、氧乐果在酸性条件下与氯化钯反应显色的规律性;对3种农药的颜色传感器快速检测法进行了研究;并以小白菜为检测样本,优化了蔬菜预处理方法.研究表明:在蒸馏水介质中,最佳工作条件是pH值为2.7,显色时间取8min.最佳预处理方法为:二氯甲烷作为有机溶剂,超生辅助萃取,浸提10min,活性炭脱色.颜色传感器检测法检测速度快,适合现场快速检测的要求. 相似文献
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基于AVR单片机农产品农药残留检测系统设计 总被引:1,自引:0,他引:1
提出了一种采用ATmega16单片机快速检测农产品农药残留的方法.检测系统利用农药对酶活性抑制的特性,通过硅光电池表现出吸光度差,测量出酶抑制率得到农药的残留量.DS1820测量系统的温度确保测量的准确性. 相似文献
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对山西省2015—2016年在生产基地、批发市场和超市抽检的588个叶菜类蔬菜样品中48种农药残留进行检测,结果表明:山西省叶菜类蔬菜农药残留超标高于蔬菜整体水平,超标严重;超标的蔬菜以芹菜和油麦菜居多;超标农药品种以禁用农药克百威和氧乐果居多,常规农药以毒死蜱和阿维菌素居多;外省农药残留超标高于山西省0.5个百分点。提出了加强农药质量的管理,杜绝隐形成分含量;加大禁用农药的查处,实现禁用农药负增长;强化标准化生产的管理,加大普通基地认证力度;加大检测力度,用检测数据指导生产等治理对策。 相似文献
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《Journal of Agricultural Engineering Research》1998,69(3):249-254
A model to represent the discolouration of dried powder of carrots as a function of temperature was developed. Two types of carrots, Asian and European, containing large amount of lycopene and β-carotene, respectively, were tested. The dried powder was stored under an atmosphere with O2and at three different temperatures, 5,20 and 35°C. The surface colour of the powder was monitored during storage by a Hunter colour ratioa/b. In the proposed model, the rate of oxidation was assumed to be represented by the product of the fraction of concentration of oxidized pigment at arbitrary time and a specific rate of oxidation of pigment. The rate parameters in the proposed model were calculated by fitting the experimental data with smooth curves by trial and error at the end of the induction period but before discolouration took place. The frequency constant and activation energy, expressing the temperature dependence of the rate parameters, were expressed by the Arrhenius relation. The simulation results of a Hunter colour ratioa/bof dried powder at 25°C showed good agreement with the experimental data, suggesting that the proposed model was effective for the prediction of discolouration of dried powder of both types of carrot. The use of the induction period in the manner described may enable the shelf life of dried powder to be predicted. 相似文献
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感官检验棉花的品级,这是农村常见的一种检测手段.它的一个主要特点就是存在不确定性.这是由于检验员的品级检验水平存在一定的差异,其中有很多因素制约着检验的结果.文章对影响感官检验结果的因素进行了系统的分析. 相似文献
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The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance. 相似文献
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从灾害经济学的角度探讨了城镇供水优化调度的必要性和可能性,认为在缺水不可避免的情况下,对供水进行优化调度可以减小缺水带来的损失,产生较好的减灾效益,特别是可以大大减小严重干旱的灾害效应。并根据水资源的特性,提出了缺水损失的计算模式以及优化调度的原则和方法。 相似文献