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统一的管阵流固耦合均匀化模型 被引量:3
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作者 张若京 《力学学报》 EI CSCD 北大核心 1997年第2期220-223,共4页
采用渐近均匀化方法,得到了管阵流固耦合的两套完全等价的控制方程,发现它们正好分别是Schumann和Banner在1981年和Brochard和Hammami在1991年提出的两套方程,给出了相应的两套参数之间的相互... 采用渐近均匀化方法,得到了管阵流固耦合的两套完全等价的控制方程,发现它们正好分别是Schumann和Banner在1981年和Brochard和Hammami在1991年提出的两套方程,给出了相应的两套参数之间的相互联系.这说明,由于本文的推导。 展开更多
关键词 管阵 流固耦合 均匀化 流体-固体冲击
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管阵流体弹性不稳定性分析 被引量:2
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作者 吴一红 王勗成 《应用力学学报》 CAS CSCD 北大核心 1993年第2期15-21,共7页
在设计换热器、蒸汽发生器等核电站和石油化学工业设备的管阵时都会遇到横向流作用下的流体诱发振动问题.无论是从引起振动的可能性,还是从产生振动后的危害性来看,流体弹性不稳定性是管阵流体诱发振动的最重要机理.本文在比较、分析现... 在设计换热器、蒸汽发生器等核电站和石油化学工业设备的管阵时都会遇到横向流作用下的流体诱发振动问题.无论是从引起振动的可能性,还是从产生振动后的危害性来看,流体弹性不稳定性是管阵流体诱发振动的最重要机理.本文在比较、分析现行的流体弹性不稳定性数学模型的基础上,提出了一种新的数学模型,给出了不稳定性临界流速的计算方法,开发了相应的计算机程序.与实验结果和其它理论模型的计算结果比较表明:本文模型应用方便,得到的结果与实验结果基本一致. 展开更多
关键词 管阵 流体弹性 不稳定性分析
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在横向气流中螺旋管管阵动态响应的研究
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作者 刘瑞兰 张东初 《华北水利水电学院学报》 1997年第1期82-85,共4页
对螺旋管管阵在横向气流冲刷下的振动响应进行了实验研究,所获得管子的加速度。
关键词 螺旋管 管阵 加速度 传感器 传热管
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螺旋管管阵流弹不稳定性的实验研究——螺旋管管阵固有频率的测量
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作者 刘瑞兰 《华北水利水电学院学报》 1996年第4期84-88,共5页
对螺旋管管阵在两端固支条件下的固有频率和阻尼进行了实验测定。
关键词 固有频率 螺旋管 管阵 流弹不稳定性 核电站
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Comparative analysis of chemical components between barks and leaves of Eucommia ulmoides Oliver 被引量:10
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作者 周菊峰 张泰铭 +1 位作者 陈望爱 梁逸曾 《Journal of Central South University》 SCIE EI CAS 2009年第3期371-379,共9页
The chemical components of the essential oils in the barks and leaves of Eucommia ulmoides Oliver were analyzed and compared by chromatograms and mass spectra technique, heuristic evolving latent projections (HELP), a... The chemical components of the essential oils in the barks and leaves of Eucommia ulmoides Oliver were analyzed and compared by chromatograms and mass spectra technique, heuristic evolving latent projections (HELP), alternative moving window factor analysis (AMWFA) algorithms and normalization method based on the peak areas; the flavones in the barks and leaves of Eucommia ulmoides Oliver were separated on an ODS column by gradient elution carried out with the flow phase consisting of water, methanol and phosphoric acid (0.1%), and their contents were quantitatively determined by standard curve method and diode array detection (DAD) at 362 nm. The results show that 68 and 73 compounds respectively from essential oils of the barks and leaves of Eucommia ulmoides Oliver are identified, and there are 33 mutual compounds among 108 compounds determined. The total contents of these volatile components of the two samples possess 92.9% and 97.75% of the gross of the relevant essential oils, respectively; the contents of the rutin, quercetin and kaempferol in the barks and leaves of Eucommia ulmoides Oliver are 0.016 9, 0.003 6, 0.002 1 and 0.064 4, 0.030 2, 0.010 0 mg/g, respectively, and the determination recoveries are 95.2%-106.2%. The comparative analysis shows that for the barks and leaves of Eucommia ulmoides Oliver, there are significant differences in their components of the relevant essential oils and flavones. 展开更多
关键词 couple chromatography chemometric algorithm comparative analysis essential oil FLAVONE Eucommia ulmoides Oliver
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Adjustable transmission properties through ring-shaped nanotube arrays using finite-difference time-domain method
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作者 周凤麒 刘志敏 +1 位作者 李宏建 刘二根 《Journal of Central South University》 SCIE EI CAS 2014年第8期3013-3018,共6页
Metallic ring-shaped nanotube arrays are proposed and its optical transmission properties are studied by using finite-difference time-domain (FDTD) method. Compared with the transmission spectra of conventional circ... Metallic ring-shaped nanotube arrays are proposed and its optical transmission properties are studied by using finite-difference time-domain (FDTD) method. Compared with the transmission spectra of conventional circular nanotube arrays, two photonic band gaps are emerged in the transmission spectra offing-shaped nanotube arrays, the two band gaps and transmission spectra are adjusted by the length, inner radius, intertube spacing and the dielectric constants of the core and embedding medium, and magnitude modification, redshift and blueshift of the resonance modes are observed. A metallic ring-shaped nanotube arrays for subwavelength band-stop filter in the range of visible light can be achieved. To understand its physical origin, field-interference mechanism was suggested by the field distributions. The proposed nanostructures and results may have great potential applications in subwavelength near-field optics. 展开更多
关键词 ring-shaped nanotube arrays PLASMON transmission spectrum finite-difference time-domain (FDTD) OPTIMIZATION
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