共查询到15条相似文献,搜索用时 187 毫秒
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旨在为湿米粉生产企业改进工艺、优化运输贮藏条件提供技术支持。以课题组开发的2N+2L标准湿米粉、旧工艺的湿米粉和市售湿米粉3种不同工艺的产品为研究对象,探讨其在不同贮藏温度下品质的变化规律,建立湿米粉的动力学模型并预测其货架期。结果显示,在4℃、10℃及25℃下贮藏的3种不同工艺湿米粉,微生物指标和感官指标对品质劣变均有一定影响。2N+2L标准的湿米粉在4℃、10℃及25℃下货架期分别为96 h、72 h和36 h,优于其他2种产品。在此基础上,以感官品质的整体接受度为限制因子指标,建立了3种产品的货架期预测模型。经验证,该模型的预测值与实测值相对误差小于10%,表明模型准确有效,在湿米粉行业具有良好的应用前景。 相似文献
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在对机械产品进行"功能-运动-动作"结构化分解的基础上,将影响元动作装配单元装配精度的误差源分为零部件的形状误差、位置误差、装配位置误差和运动误差等四类误差源。引入误差链接模型作为元动作装配单元误差关联关系的基本封装单元,构建结构化误差关联模型——链接网络和链接矩阵,形象描述误差间的耦合嵌套关系。提出基于误差链接模型的装配误差传递路径求解方法,用老鼠迷宫算法搜索所有可能的误差传递路径,以装配精度最高作为判别依据,得到各误差分量的有效传递路径。以蜗杆转动元动作装配单元蜗杆轴线平行度误差有效传递路径为目标,对上述方法进行验证,结果表明该方法能够高效地搜索到所有误差传递路径,并快速获得有效传递路径。该方法的提出为整机装配过程质量预测与控制提供了理论依据。 相似文献
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Its rationality of temperature and water vapor partial pressure as driving potential for coupled heat and moisture transfer was demonstrated based on non-equilibrium thermodynamics. As water vapor partial pressure is a function of moisture content and temperature, mathematical model of coupled heat and moisture transfer for multilayer wall were established according to the theory of total differential. The approximate expressions between humidity content and relative humidity of air used in Budaiwi method could be avoided. The coefficients of mathematical model were simplified and could improve efficiency of solution. Its validation was illustrated by contrasting and analyzing the simulation results of a multilayer wall. 相似文献
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A coupled heat and moisture transfer model on reinforced concrete under high temperature was provided,then the heat and moisture transfer theory on reinforced concrete under fire disaster was analysed in this paper.The numerical simulation and field measurement data show that the model can roughly explain the actual heat and moisture transfer progress of reinforced concrete under fire disaster. 相似文献
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According to the work of Motakef and EI-Masri, the wall was divided into dry-wet-dry zones. Based on the heat and moisture transfer through porous media, considering the vapour condensation as a vapour sink, water source and heat source, coupled heat and moisture equations for wet zone were established. Closed-form analytical expressions for the condensation rate, moisture content and the time when critical moisture content value reached are obtained. It is indicated that the condensation rate exhibits a strong dependence on the temperature difference of the two sides of wet zone, and the maximum condensation rate value is reached at the boundary of wet zone close to lower temperature. 相似文献
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通风干燥过程中的粮食水分转移规律研究 总被引:2,自引:1,他引:1
对粮食机械通风过程中的热质交换进行了细致和深入的探讨,应用热质交换理论分析粮食通风干燥中的温度变化和水分转移规律,避免无效通风和有害通风,并通过全开孔地板试验仓模拟试验验证了降温降水效应、粮食吸附滞后、各层粮食水分变化和干燥前沿推进规律。 相似文献
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This paper discusses the procesa of mass lase for fruit in a cold storage with theo-ry of mass transfer and shows that fruit mass loss under constant storage temperature is relative tothe temperature,humidity and moisture diffusive factor,which can give theoretical base for some ac-tual methods for measuring technique decreasing mass loss. 相似文献