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本文对空气环境中氩等离子体射流冲击平板条件下冷壁附近的电子温度,采用静电探针方法进行了测量.研究了等离子体温度、速度以及平板至发生器出口距离等参数的影响.实验结果表明,在冷壁面附近,电子温度总是明显高于相应的重粒子温度,从而证明在等离子体射流冲击平板条件下冷壁附近的边界层显著偏离局域热力学平衡(LTE)状态.实验结果还表明,探针污染是影响测量结果可靠性的一个重要因素. 相似文献
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This paper presents a comprehensive comparison of the mean velocity and turbulence measurements from a four-hole pressure probe, also known as the Cobra probe, and an X-probe in plane mixing layers. The objective is to validate the measurement accuracy of the Cobra probe in a flow where the turbulence reaches high levels, but whose properties are well known. The comparison is made for the mean velocities, Reynolds stresses, triple products, and spectra, and demonstrates that the Cobra probe has reasonable accuracy for some of these quantities, such as the mean streamwise velocity and primary shear stress, but not for others, such as the mean normal velocity. The correlation of the pressure and the streamwise velocity, measured by the Cobra probe, behaves correctly in the potential flow. However, the correlation of the pressure and the cross-stream velocity, which appears in the transport equation for the turbulent kinetic energy, and the pressure redistribution term in the corresponding equation for the streamwise normal stress, are poorly measured. 相似文献
996.
E. Nguyen Cong Duc L. Fournier C. Levecq B. Lesjean P. Grelier A. Tazi-Pain 《Journal of membrane science》2008
The better understanding of the effective air distribution inside a membrane cassette is a particular challenge in submerged membrane bioreactor. The present study is the first one that investigates the hydrodynamics of the coarse bubbles flow inside a hollow fibre membranes cassette. The experimental investigations were carried out in a reactor equipped with commercial modules from ZENON ZeeWeed® 500d. A bi-optical probe was used to measure the bubble size, the bubble velocity and the gas hold-up at different locations between the modules and for three different gas flow rates. These local measurements gave significant information about the lateral distribution of the air and its evolution with the height on the surface of the membrane modules, which can impact on the filtration performance and are the first step to an optimisation of the aeration system and module geometry. 相似文献
997.
Y. Kunieda K. Nagashima N. Hasegawa Y. Ochi 《Spectrochimica Acta Part B: Atomic Spectroscopy》2009,64(8):744-746
A new X-ray detector using surface plasmon resonance (SPR) is proposed. The detector consists of a prism coated with a thin metal film and semiconductor film. Optical laser pulse induces SPR condition on the metal surface, and synchronized X-ray pulse which is absorbed into the semiconductor film can be detected by measuring the change of the resonance condition of the surface plasmon. The expected time and spatial resolution of this detector is better than that of conventional X-ray detectors by combining this SPR measurement with ultra-short laser pulse as the probe beam. Our preliminary investigation using Au and ZnSe coated prism implies this scheme works well as the detector for the ultra-short X-ray pulse. 相似文献
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O. M. Kostenko S. Y. Dmitrieva O. I. Tolmachev S. M. Yarmoluk 《Journal of fluorescence》2002,12(2):173-175
New approach for fluorescent peptide labeling with cyanine dyes utilizing the reaction of pyrylium salts with aliphatic aminogroup is proposed. The reaction of two pyrylium cyanines dye acids was investigated. Lysocyme was used as a model peptide for conjugation. The proposed method can be used as a simple and convenient alternative for the known procedures because it does not require preparation of the unstable amino-reactive intermediates from a carboxyl- or sulfo-derivative of cyanine dyes. 相似文献
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Measurement of concentration distributions of suspended particles in a micro-channel is one of the most crucial necessities in the area of Lab-on-a-chip to be used for various bio-chemical applications. One most feasible way to measure the concentration field in the micro-channel is using μ-LIF (micro-scale laser-induced fluorescence) method. However, an accurate concentration field at a given cross-plane in a micro-channel has not been successfully achieved so far due to various limitations in the light illumination and fluorescence signal detection. The present study demonstrates a novel method to provide an ultra-thin laser sheet beam having 5 μm thickness using a micro-focus laser line generator. The laser sheet beam illuminates an exact plane of concentration measurement field to increase the signal-to-noise ratio and considerably reduce the depth uncertainty.Nile Blue A was used as fluorescent dye for the present LIF measurement. The enhancement of the fluorescent intensity signals was performed by a solvent mixture of water (95%) and ethanol (EtOH)/methanol (MeOH) (5%) mixture. To reduce the rms errors resulting from the CCD electronic noise and other sources, an expansion of grid size was attempted from 1×1 to 3×3 or 5×5 pixel data windows and the pertinent signal-to-noise level has been noticeably increased accordingly. 相似文献