共查询到20条相似文献,搜索用时 140 毫秒
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介绍了缠绕设备张力控制系统的组成和一般概念,基本控制方式和目前发展状况,分析了设计过程中要考虑的主要问题.针对纤维缠绕中张力控制的特点,提出用变频器控制的方法,并说明其基本原理,讨论了变频器在纤维缠绕中应用的实用性. 相似文献
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介绍了汽车点火线圈在真空树脂灌注过程中的多通道智能温度测控系统,并详细描述了系统硬件、软件的设计与实现过程。该系统主要以工业控制计算机和PCI-2300多功能数据采集卡作为硬件平台,Visual C 6.0作为软件开发平台,另外提出了基于专家经验的智能温度控制算法,将控制精度稳定在±0.5℃范围之内。经现场实际运行表明:该系统能够满足设备实时控制的要求,保证了产品质量,为企业创造了经济效益。 相似文献
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为保持手术缝合线涂层工艺过程中丝线张力的稳定性,通过分析传统张力的控制方式及其局限性,提出了一种基于速度跟随原理的张力自稳定系统。该系统采用主动放线方式,从动力学角度建立放线系统张力控制模型,设计弹簧-张力杆机构。通过实时检测走线过程中张力的波动,改变主动放线速度,从而减小走线过程中丝线张力的波动幅度,提高系统稳定性。构建了虚拟样机,在ADAMS中进行动力学仿真,仿真结果表明该弹簧-张力杆机构能将张力的波动幅度减小70%。最终以与强生(中国)医疗器材有限公司共同研制的四头上蜡机作为测试对象,与传统设备相比,该方案可将张力的波动幅度减小53%。 相似文献
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连续搅拌反应釜(Continuously Stirred Tank Reactor,CSTR)是工业生产中常用的设备,其温度系统具有强非线性、耦合性、时变性的特点,反应机理复杂,精确建模困难,传统控制方法很难满足生产需要。为解决上述问题,采用基于数据驱动的无模型自适应方法(Model Free Adaptive Control,MFAC)对反应釜出料温度进行控制。在SIMULINK环境下搭建反应釜数学模型,采用基本MFAC方法对其进行仿真研究,针对控制器参数调整复杂的问题,采用模糊控制方法对无模型控制器参数进行优化。仿真实验结果表明,基于模糊控制的MFAC方法改善了系统动静态性能指标,系统的抗干扰能力和自适应能力得到增强。该方法对反应釜实际生产具有一定的指导作用。 相似文献
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论文主要介绍了连续式超临界水氧化实验装置设计.在该系统中,最主要的设备就是反应釜,其设计温度500℃,设计压力35MPa.论文对整个系统进行了详细的叙述,包括进料系统、反应釜的结构设计等.反应器是系统的主要设计部分,本文对反应釜进行了设计计算. 相似文献
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In this research work, a low-temperature examination method for scanning electron microscopy (SEM) is introduced. A water-absorbable polymer material, the sulfonated polyethylene (SPE) ion-exchange hollow fiber membrane, was used for the experiments. With this low-temperature technique, the wet morphology of the water-absorbable sulfonated polyethylene hollow fiber membrane was revealed. The results obtained from this investigation offer some important information to explain the behavior of the SPE hollow fiber membranes when they are applied in pervaporation separation of water/organic solvent mixtures, such as water/ethylene glycol, water/ethanol, and so forth. 相似文献
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In this research work, a low-temperature examination method for scanning electron microscopy (SEM) is introduced. A water-absorbable polymer material, the sulfonated polyethylene (SPE) ion-exchange hollow fiber membrane, was used for the experiments. With this low-temperature technique, the wet morphology of the water-absorbable sulfonated polyethylene hollow fiber membrane was revealed. The results obtained from this investigation offer some important information to explain the behavior of the SPE hollow fiber membranes when they are applied in pervaporation separation of water/organic solvent mixtures, such as water/ethylene glycol, water/ethanol, and so forth. 相似文献
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The goal of this work is to design and build an impiantatile artificial lung that can be inserted as a whole into a large
vein in the body with the least effect on cardiovascular hemodynamics. The experimental results demonstrate that the pressure
drop is not entirely related to viscosity effects. The friction factor decreases with an increase in the number of tied-hollow
fibers at a constant Reynolds number. A uniform flow pattern without stagnation is observed at all numbers of tied hollow
fibers tested. The tied hollow fiber module, built in this study with 3 cm of outer diameter of module, 380 m of outer diameter
of tied hollow fiber, and 700 number of tied hollow fiber with length of 60 cm, which shows a pressure drop of 13–16 mmHg,
satisfies the required pressure drop qualifying 15 mmHg as an intravascular artificial lung. 相似文献
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In this paper, a sensitive-enhanced single-mode fiber—tapered hollow core fiber—single-mode fiber Mach–Zehnder interferometer is demonstrated for refractive index sensing. The sensitivity was improved by forming an up-taper at the two splicing joints and concave cone in hollow core fiber. The up-tapered regions served as a more effective mode splitter/combiner, and the tapered hollow core fiber was used to generate a stronger evanescent field to enhance the interaction of light with the analyte. According to the principles of interference between the cladding and fundamental modes, we performed refractive index measurements. The experiments indicated that the proposed sensor has a high refractive index sensitivity of 214.97?nm/RIU in the refractive index range of 1.333–1.379, with a minimum refractive index measurement resolution of 9.3?×?10?5. In addition, the sensor had a low temperature response of 2.96?pm/°C in the range from 50 to 85°C and a low cross sensitivity of 1.377?×?10?5 RIU/°C. The proposed sensor is attractive for its high refractive index sensitivity, easy fabrication, low cross sensitivity, and good mechanical strength, making it of potential value for refractive index measurements for chemical and biological sensing. 相似文献
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提出了基于曲线拟合的光纤透镜聚焦常数的测试方法,用于超小自聚焦光纤探头研制过程中聚焦常数的直接测试。基于自聚焦光纤透镜模型及其折射率分布特征,研究了测量自聚焦光纤透镜聚焦常数的二次多项式拟合和线性化拟合算法。论述了聚焦常数对超小自聚焦光纤探针传光性能的影响。利用光纤端面折射率测试仪测试自聚焦光纤的折射率分布轮廓曲线,根据二次多项式拟合和线性化拟合算法分别求得聚焦常数和中心折射率。实验结果显示,利用二次多项式拟合算法和线性拟合算法求出的聚焦常数分别为5.587mm-1和5.513mm-1,与厂家的标称值5.5mm-1基本吻合,表明曲线拟合算法适用于对自聚焦光纤透镜聚焦常数的测量与分析。 相似文献
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为了设计用于光频域反射仪(optical frequency domain reflectometer, OFDR)温度传感的涂层光纤,提升OFDR的温度灵敏度,增加其适用场景,从理论上分析了1层和2层涂层对单模光纤中瑞利频移温度灵敏度的影响并进行了仿真。考虑到外涂层的几何、热和机械性能,首先,用Lame解理论分析涂层对OFDR瑞利频移温度灵敏度的影响;其次,基于温度带来的光纤轴向应变关系以及光纤与1层涂层之间的力平衡,提出了仅含1层涂层的简化解;最后,针对建立的理论模型,对1层以及2层外涂层光纤的瑞利频移温度灵敏度进行了仿真。结果表明,瑞利频移温度灵敏度随着外涂层的杨氏模量、半径和热膨胀系数的增加而增加,而与涂层泊松比几乎无关。本研究结果将有助于提高OFDR在高温度灵敏度和低温场景中的应用。 相似文献
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Ionic liquids (ILs) are promising high-performance lubricants with remarkable lubrication and antiwear capabilities in tribology. In this article, first solid-state (at room temperature) IL-incorporated SiO2 hollow microspheres (IL-SiO2) were synthesized at high temperature, and then a novel epoxy (EP) composite coating filled with IL-SiO2 hollow microspheres (IL-SiO2/EP) was successfully fabricated. The effects of IL- SiO2 on the mechanical and tribological properties of the IL-SiO2/EP coating were investigated. It was found the IL-SiO2/EP coating possessed low friction and high wear resistance. When the IL ratio in the silica hollow microspheres was 58%, the flexural strength and hardness of the IL-SiO2/EP coating surpassed those of the SiO2/EP coating and pure EP coating. When the IL-SiO2 content was 15?wt% in the composite, the friction coefficient and wear rate of the IL-SiO2/EP coating were both minimized and were 46.2 and 81.6% lower than those of the SiO2/EP coating, respectively. It was indicated that the addition of ILs overcame the heat and electron accumulation of SiO2/EP coating in the friction process. The solid-state ILs were melted by friction heat and load into the lubricating liquid and released from the hollow silica microspheres to the worn surfaces, which was similar to sweating by the human body. In addition, the liquid-state ILs combined with the debris of EP through chemical bonding to form an internal continuous and steady lubricating protective film, which could directly protect the worn surfaces from abrasion. This IL-SiO2/EP composite coating can be used to design and fabricate new sweating-lubricating functional coatings. 相似文献
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An optical fiber sensor based on a multimode tapered fiber cascading fiber Bragg grating has been proposed and experimentally demonstrated for the simultaneous measurement of humidity and temperature. The sensor was constructed using a tapered fiber that was coated with polyvinyl alcohol and a fiber Bragg grating with high reflectivity. The measurement of humidity and temperature was achieved by monitoring changes in reflective optical power and spectral shift, respectively. Due to the different measurement methods, the effect of temperature on humidity measurement may be ignored. The theoretical analysis and experimental results show that the highest sensitivities of 0.33 µW/%RH and 10.9?pm/°C were achieved when the diameter of the taper waist was 26?µm and the thickness of coating was 3.3?µm. Due to the advantages of good linearity, low cost of fabrication and convenient operation, the proposed sensor is promising for simultaneously measuring humidity and temperature. 相似文献