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Optimization of plasma-processed air(PPA)inactivation of Escherichia coli in button mushrooms for extending the shelf life by response surface methodology 被引量:1
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作者 Zitong ZHAO Xiangyou WANG +1 位作者 Tingjun MA Yunjin SUN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第6期128-136,共9页
The effect of plasma-processed air(PPA)treatment with different conditions(time,power andflow rate)on the inactivation of Escherichia coli(E.coli)in button mushroom was evaluated.Response surface methodology(RSM)was a... The effect of plasma-processed air(PPA)treatment with different conditions(time,power andflow rate)on the inactivation of Escherichia coli(E.coli)in button mushroom was evaluated.Response surface methodology(RSM)was applied to optimize PPA treatments on the E.coli of button mushrooms.According to the response surface analysis,the optimal treatment parameters were a treatment time of 12 min,treatment power of 90 W and flow rate of 1.2 l min-1.As with verifying tests from the optimization exercise,the number of E.coli reduced by 5.27 log CFU/g at the determined optimum conditions.The scanning electronic microscopy(SEM)micrography showed that the surface of the E.coli was significantly changed under the optimized PPA treatment.Quality parameters of button mushrooms treated at the determined optimum conditions were compared with untreated samples during the storage for 12 d at 4°C?±?1°C.The PPA treatment was found to be effective in inhibiting microbes and preserving postharvest quality in button mushrooms,and these results suggested PPA treatment may provide an alternative for the sterilization of foodborne and maintaining postharvest of fruits and vegetables. 展开更多
关键词 plasma processed air(ppa) INACTIVATION response surface methodology button mushrooms
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PPA与热法磷酸制备活性炭差异性研究 被引量:1
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作者 李文飞 张丹 +1 位作者 郭举 刘美霞 《广州化工》 CAS 2015年第21期102-103,153,共3页
采用食品级净化磷酸(食品级PPA)以及热法磷酸分别制备了活性碳,并对比研究了两种活性碳对亚甲基蓝的吸附率、灰份含量、磷酸回收率、活性碳收率等参数,同时引入电子级磷酸为参照,结果表明:以两种磷酸为原料制备的活性炭产品对亚甲基蓝... 采用食品级净化磷酸(食品级PPA)以及热法磷酸分别制备了活性碳,并对比研究了两种活性碳对亚甲基蓝的吸附率、灰份含量、磷酸回收率、活性碳收率等参数,同时引入电子级磷酸为参照,结果表明:以两种磷酸为原料制备的活性炭产品对亚甲基蓝的吸附率、灰份含量、磷酸回收率、活性碳收率等参数相差不大,食品级PPA可以取代热法磷酸用于活性炭制备工业,但其中电子级磷酸对亚甲基蓝的吸附率及灰分大小表现出了优异的性能。 展开更多
关键词 食品级ppa 热法磷酸 活性炭 灰分 亚蓝值
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Impact of Die Materials on the Effect of New Polymer Processing Aids for Sharkskin Properties
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作者 Seyed Pooyan Sajjadi 《Journal of Materials Science and Chemical Engineering》 2016年第9期17-27,共12页
Flows of polymeric liquids undergo instabilities whose origins are quite different from those of Newtonian flows, due to their elastic character and the complexity of the fluid/solid boundary condition. One of these i... Flows of polymeric liquids undergo instabilities whose origins are quite different from those of Newtonian flows, due to their elastic character and the complexity of the fluid/solid boundary condition. One of these instabilities is well known as “shark-skin” which damages the surface appearance and properties of polymer extrudate while processing in blowmolding or piping, while it can be suppressed by employing various methods including coating the die surface and/or adding Polymer Processing Aid’s (PPA) to the polymer. In this article, the effect of various die materials on the properties of Polyethylene glycol (PEG) as a new type of PPA for suppressing the sharkskin phenomenon has been studied. 展开更多
关键词 Polymer processing Aids (ppa) PEG SHARKSKIN Extrusion Instabilities
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基于邻域保持嵌入的主多项式非线性过程故障检测 被引量:7
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作者 李元 姚宗禹 《上海交通大学学报》 EI CAS CSCD 北大核心 2021年第8期1001-1008,共8页
针对化工过程的变量数据维数高、非线性的问题,提出基于邻域保持嵌入(NPE)-主多项式分析(PPA)的过程故障检测算法.应用NPE算法提取高维数据的低维子流形,能够解决传统的线性降维算法不能提取局部结构信息的问题,对维数进行约减.利用PPA... 针对化工过程的变量数据维数高、非线性的问题,提出基于邻域保持嵌入(NPE)-主多项式分析(PPA)的过程故障检测算法.应用NPE算法提取高维数据的低维子流形,能够解决传统的线性降维算法不能提取局部结构信息的问题,对维数进行约减.利用PPA法时,使用一组灵活的主多项式分量来描述数据,能够有效地捕捉过程数据中固有的非线性结构.在降维后的流形空间进行主多项式分析并建立Hotelling’s T^(2)和平方预测误差统计量模型,同时确定控制限以进行故障检测.最后,通过一组非线性数值实例和Tennessee Eastman化工过程数据,将NPE-PPA算法与传统的核主元分析法、PPA法进行对比分析,验证所提算法的有效性及优越性. 展开更多
关键词 邻域保持嵌入 主多项式分析 非线性过程 故障检测
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两种不同的4-溴甲基喹啉酮合成方法的分析对比
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作者 白瑞娇 宋明峰 +2 位作者 张斌 郑井瑞 李雅芙 《盐科学与化工》 CAS 2023年第6期25-28,共4页
生产4-溴甲基喹啉酮有两种不同的合成途径,分别为浓硫酸环化法以及PPA环化法。文章通过对这两种不同的制备方法的产物收率、产物含量、制备过程中产生的环境污染等方面对不同的合成路径进行了综合分析对比,解析了不同合成路线中各步的反... 生产4-溴甲基喹啉酮有两种不同的合成途径,分别为浓硫酸环化法以及PPA环化法。文章通过对这两种不同的制备方法的产物收率、产物含量、制备过程中产生的环境污染等方面对不同的合成路径进行了综合分析对比,解析了不同合成路线中各步的反应,为后续4-溴甲基喹啉酮的大规模工业合成提供了数据及理论支持。 展开更多
关键词 4-溴甲基喹啉酮 合成路径 浓硫酸环化法 ppa环化法
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Evaluation Indexes of Degree of Closeness between Strategy and Project Portfolio Allocation
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作者 Libiao Bai Sijun Bai 《American Journal of Operations Research》 2015年第1期38-46,共9页
The main activities in project portfolio allocation management are selecting the right project components given a strategy. It is crucial to establish a scientific system of evaluation indexes to guarantee the closene... The main activities in project portfolio allocation management are selecting the right project components given a strategy. It is crucial to establish a scientific system of evaluation indexes to guarantee the closeness between strategy and project portfolio allocation optimally. With organizations growing in sizes, the functions and objectives of project components are becoming more and more different. It is necessary to set evaluation indexes of the degree of closeness from the perspectives of financial, market share, social effects, and so on according to the strategy-oriented process of project portfolio allocation. This paper proposes a project portfolio allocation process under strategic orientation and evaluation indexes of the degree of closeness between strategy and project portfolio allocation. This will help projects managers make portfolio allocation decisions. 展开更多
关键词 PROJECT PORTFOLIO ALLOCATION Evaluation Indexes DEGREE of CLOSENESS ppa process
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