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基于串级模糊自适应PID的蒸发器温度控制系统设计 被引量:6
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作者 孙军 张典 +3 位作者 黄青山 田亮 常天奇 刘琪 《过程工程学报》 CAS CSCD 北大核心 2023年第9期1290-1300,共10页
蒸发器温度控制存在时变性、非线性和滞后时间长等特性,传统控制方法难以实现温度的精确控制。通过对蒸发器的生产过程进行分析,提出了一种基于串级模糊自适应比例-积分-微分(PID)的蒸发器温度控制方法,将模糊控制理论和串级PID控制理... 蒸发器温度控制存在时变性、非线性和滞后时间长等特性,传统控制方法难以实现温度的精确控制。通过对蒸发器的生产过程进行分析,提出了一种基于串级模糊自适应比例-积分-微分(PID)的蒸发器温度控制方法,将模糊控制理论和串级PID控制理论相结合,建立了主回路和副回路的模糊自适应PID控制连续功能图(CFC),实现了对蒸发器温度控制的主回路和副回路PID参数的实时修正。采用SMPT-1000仿真设备和西门子PCS7过程控制系统的研究结果表明:PID参数实时修正后,比例参数加快了系统响应速度,积分参数减小了系统的偏差,微分参数起到了超前控制作用;温度响应的调节时间缩短二分之一,最大偏差降低幅度超过五分之四;温度提升负荷的调节时间缩短幅度超过五分之三,最大偏差降低幅度超过五分之四;过热蒸汽干扰的恢复时间缩短幅度超过二分之一,最低和最高温度偏差降低幅度超过十分之一。与传统串级PID控制方法相比,串级模糊自适应PID控制具有调节时间短、超调量小、鲁棒性好等优势,克服了传统串级PID的不足,为解决蒸发器温度精确控制提供了一种有效途径和方法。 展开更多
关键词 蒸发器 温度控制 串级模糊自适应PID PCS7 SMPT-1000
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Release of VEGF and BMP9 from injectable alginate based composite hydrogel for treatment of myocardial infarction 被引量:10
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作者 Yong Wu tianqi chang +7 位作者 Weiqian Chen Xiaoyu Wang Jingjing Li Yueqiu Chen You Yu Zhenya Shen Qian Yu Yanxia Zhang 《Bioactive Materials》 SCIE 2021年第2期520-528,共9页
Myocardial infarction(MI)is one of cardiovascular diseases that pose a serious threat to human health.The pathophysiology of MI is complex and contains several sequential phases including blockage of a coronary artery... Myocardial infarction(MI)is one of cardiovascular diseases that pose a serious threat to human health.The pathophysiology of MI is complex and contains several sequential phases including blockage of a coronary artery,necrosis of myocardial cells,inflammation,and myocardial fibrosis.Aiming at the treatment of different stages of MI,in this work,an injectable alginate based composite hydrogel is developed to load vascular endothelial active factor(VEGF)and silk fibroin(SF)microspheres containing bone morphogenetic protein 9(BMP9)for releasing VEGF and BMP9 to realize their respective functions.The results of in vitro experiments indicate a rapid initial release of VEGF during the first few days and a relatively slow and sustained release of BMP9 for days,facilitating the formation of blood vessels in the early stage and inhibiting myocardial fibrosis in the long-term stage,respectively.Intramyocardial injection of such composite hydrogel into the infarct border zone of mice MI model via multiple points promotes angiogenesis and reduces the infarction size.Taken together,these results indicate that the dual-release of VEGF and BMP9 from the composite hydrogel results in a collaborative effect on the treatment of MI and improvement of heart function,showing a promising potential for cardiac clinical application. 展开更多
关键词 Myocardial infarction Injectable hydrogel Silk fibroin microspheres ANGIOGENESIS Myocardial fibrosis
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Biomaterials based cardiac patches for the treatment of myocardial infarction 被引量:1
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作者 tianqi chang Chunxia Liu +6 位作者 Kunyan Lu Yong Wu Mingzhu Xu Qian Yu Zhenya Shen Tingbo Jiang Yanxia Zhang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第35期77-89,共13页
Myocardial infarction(MI)is one of the common cardiovascular diseases that occurs with a blockage in one or more of the coronary arteries to lead to the damage of the myocardium,resulting in a lifethreatening conditio... Myocardial infarction(MI)is one of the common cardiovascular diseases that occurs with a blockage in one or more of the coronary arteries to lead to the damage of the myocardium,resulting in a lifethreatening condition.To repair the damaged myocardium in MI,researchers are looking forwards to new ways to postpone the progression of myocardial injury.Cardiac patches,the scaffolds layered on the heart surface,can provide mechanical support for the infarction site and improve cardiac function by delivering various bioactive factors or cells,showing considerable curative effect in the treatment of MI.Biomaterials with certain biocompatibility and mechanical properties have received widespread attention for the application in cardiac patches.In this review,we focus on the recent progress on these biomaterialsbased cardiac patches,which could be categorized into two types according to the sources of materials including(ⅰ)natural materials and(ⅱ)synthetic materials.The major advantages and current challenges of each type are discussed and a brief perspective on the future research directions is presented. 展开更多
关键词 BIOMATERIALS Cardiac patches Myocardial infarction
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