共查询到20条相似文献，搜索用时 31 毫秒
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食品行业粉体材料流动性研究的新仪器——PFT 总被引：1，自引：0，他引：1
奶粉、面粉、糖、盐、调味品等原料和添加剂粉体的流动性研究是目前很多材料行业的难点,现有常见的一些方法不能满足实际的需求。简单介绍了Brookfield公司根据ASTM D 6128推出的PFT粉体流体测试仪的基本功能,介绍了粉体流动函数、壁面摩擦、松装密度、时间固结、拱架、鼠孔、料斗半角的测量和计算。 相似文献
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In today's manufacturing enterprise,material,energy and information are three basic elements,and energy system is a sub-system in it.Based on the static input-output relationship derived from the energy flow and material flow net diagram,W.Leontief type dynamic input-output model with one step delay is developed.With LQR optimal control method,a dynamic input-output energy system of manufacturing enterprise has been built for planning of production capacities,the distribution of resources,and the dynamic balancing of system.An illustrated example is presented. 相似文献
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Load dynamic matching of supply and demand side based on the utilization of urban sewage heat energy
Flowing dynamic characteristics and its temperature dynamic characteristics of a three-level sewage pipe network in Chongqing were analyzed. A mall's building whole year load was simulated. In the adverse condition of wastewater flow, the market construction peak discharge heat was compared with the sewage heat load, the balance between the most adverse flow and the building demand was found. Explored supply and demand matching method between urban sewage and city building load in flow adverse condition to take full advantage of the urban sewage cold and hot resources. the composite system was adeptcd to make up the most unfavorable flow time of sewage average heat load and the construction load difference; it also puts forward principle of load sharing and control strategy aimed at compound system. 相似文献
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The double drive hoist reducer developed in the planetary gear is a new generation of energy saving and environment protecting hoist product. The multi flow transmission system theory of hoist is analyzed. With the theory and method of bond graph,a bond graph model with coupled vibration is established for hoist multi flow transmission system for the first time. The state equation of the system is developed and dynamic simulation analysis is also carried out. The internal changing law and relationship of the system for the state variable are got. Therefore, the dynamic properties and gearing features of this system are revealed comprehensively. The research results can provide the dynamic analysis method and design basis for multi flow transmission system of hoist. 相似文献
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密集烘烤关键温度点不同湿度控制烤烟主要化学成分的动态变化 总被引：3，自引：2，他引：1
针对密集烘烤存在的干物质降解不充分和香气物质不足的问题,以‘K326’品种为材料,在湖南省浏阳市开展了密集烘烤关键温度点不同湿度控制烟叶化学成分动态变化研究。结果表明：（1）在密集烘烤过程中,42℃前淀粉含量迅速下降、总糖和还原糖含量及糖碱比迅速升高;42~47℃,淀粉含量缓慢下降、总糖和还原糖含量缓慢升高;在47℃后,淀粉、总糖、还原糖含量及糖碱比基本保持稳定,变化很小。（2）烟叶烟碱、总氮含量随烘烤进程略呈下降趋势,但变化较小;氮碱比变化不大。（3）在烟叶变黄期和定色期适当增加湿球温度,可使化学成分更加协调。 相似文献
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《保鲜与加工》2003,(10):52-55
This paper studies the question for considering optimal load curtailment in bulk power system adequacy evaluation. A minimization model of load curtailment is utilized for the contingency states which may have load curtailment. In order to calculate realistic bus indexes, two practical load curtailment philosophies are incorporated in the minimization model of load curtailment, which is achieved in computer program developed for bulk power system reliability evaluation. The minimization model of load curtailment, correlated algorithms, and flow chart of program are given in this paper. The effectiveness and availability of the model are verified from two case studies. 相似文献
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Qin Shuren Wang Jiachen Hu Xinyi Jiang Guongcheng 《保鲜与加工》1990,(1):1-12
The paper introduces a new method-QL system suggested for the first time by the author for measuring dynamic accuracy of gear cutting machine drivetrain. The system has many uses. It suits not only the measurement of mid-size machine tool but also the measurement of very slow speed, large ratio, large-size machine drivetrain 相似文献
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为了更好地评价大庆湿地生态系统对太阳能资源的利用情况和大庆农业的可持续发展状况。应用生态系统能值分析理论,定量地分析和估算大庆湿地生态系统的生态效益以及系统内的物流和能流。结果表明,大庆城区湿地的价值极大,从能值分析表可以得出大庆湿地生态系统自然资源价值总计为3.13×1010￥,雨水在全部的可再生资源组成中占绝对优势,所占比例约74%;湿地水体及底泥沉积物的宏观经济价值为1.61×1010 ￥,对比能值分析表中其他项目,湿地初级生产力能值及动物资源能值小于系统投入的再生资源能值,说明该系统大部分能量用于湿地生态系统的生态服务功能,而非物质的产出。 相似文献
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The principle of photoelectric imaging deflection measurement system are presented. The calculation of the image plane's illuminance and contrast are discussed. The relationship among the system's parameters are analyzed. The feasibility of high reflectivital material replacing the system's source are also discussed when illuminance on the ground is high. The result contributes to selecting the parameters of photoelectric imaging deflection measurement system and achieves the long online of deflection. 相似文献
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LU Jun CHENG Qi_gao 《保鲜与加工》1999,(6):77-81
On_site measurement and numerical modeling are made for the interior heat mass distribution. The heat and mass coupling equation system to the porous saline materials in one-dimensional temperature and mass degree field was established. The dynamic distribution features of the materials in moderate temperature and mass degree field were obtained. The result of numerical modeling coincided with that of actual measurement and testified to the numerical model. The study has significance in promoting the interrelated sciences in their studies on the problem of heat and mass transport in porous saline materials. 相似文献
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新型农户专用粮仓储粮品质变化研究 总被引：1，自引：0，他引：1
采用PVC软体仓作为新型农户专用仓,小麦在10个月储存期内水分含量变化≤0.6%,与原始水分无显著差异。小麦容重损失率均值为1.96%,干容重损失率均值2.1%,虫蚀粒率≤0.3%,霉变粒率≤0.1%,面筋吸水率变化率均值9.4%,平均储粮损失率为0.506%,干物质平均损失率为0.318%。由此可见PVC仓具有良好的防潮、防鼠、密闭、隔热等性能,能够有效地减少农户储粮过程中由粮食生虫、发热霉变、鼠咬等因素引起的储粮损失,起到减损保质的效果。 相似文献
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土壤紧实度对花生根系生长和活性变化的影响 总被引：7，自引：0，他引：7
为探究不同土壤紧实度对花生根系生长和活性变化的影响,确定花生生长所需的适宜紧实度,为花生高产新品种的选育和栽培提供理论依据。以高产花生品种青花7号为试材,采用桶栽的方法,设置土壤容重分别为1.1,1.2,1.3,1.4,1.5 g/cm35个处理,研究了土壤紧实度对花生根系生长和活性的影响。结果表明,在花生根系发展期土壤容重过大不利于根系伸长和表面积扩大,且随着生育进程的推进影响越大,在花生根系衰退期土壤容重过小根系长度和表面积衰退过快,而适宜的土壤容重(1.2 g/cm3)则既能保证根系发展期根系的伸长和表面积扩大,又能延缓根系衰退期根系长度和和表面积的衰退。土壤容重过大或过小均不利于花生根系干物重积累、根系体积增加和根系活力提高,根系直径随着土壤容重的增大而增大。认为容重为1.2~1.3 g/cm3有利于花生根系生长和活性提高。 相似文献
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中国典型储粮生态区低温储粮的优化集成方案 总被引：4，自引：1，他引：4
根据储粮生态环境,将我国分为三个典型的低温储粮生态区域,即低温区、中温区和高温区。提出了三个储粮生态区域低温储粮对仓房隔热条件和气密条件的要求及不同地区低温储粮的优化集成方案。低温区最佳的低温储粮模式是:冬季通风降温 夏季隔热 适当控温;中温区最佳的低温储粮模式是:冬季机械通风降温 夏季严格隔热 必要的控温;高温区最佳的低温储粮模式为:冬季机械通风降温或谷物冷却机降温 夏季严格隔热 谷物冷却机降温。同时给出了三个储粮生态区域低温储粮优化方案的工艺流程图。 相似文献