This paper presents the measurement of void fraction in a vapor-liquid two-phase flow system constituted by horizontal heated tube bundles. An advanced measuring system with single-fiber optical probes is developed. T...This paper presents the measurement of void fraction in a vapor-liquid two-phase flow system constituted by horizontal heated tube bundles. An advanced measuring system with single-fiber optical probes is developed. The optical couplings are used in the measuring system instead of beam-splitting lens. Measurement of void fraction has been carried out within the tube bundles of the two-phase flow test section. The measurements show that the tube bundles have significant effect on the profile of the void fraction.展开更多
Radial distribution of vapor local parameters, including local void fraction, interfacial velocity, bubblesize, bubble frequency and interfacial area concentration, are investigated through the measurement in an upwar...Radial distribution of vapor local parameters, including local void fraction, interfacial velocity, bubblesize, bubble frequency and interfacial area concentration, are investigated through the measurement in an upwardboiling tube using dual-sensor optical probe. In addition, a new local parameter -"local bubble number concentra-tion" is developed on the basis of bubble frequency. The analysis shows that this parameter can reflect bubble numberdensity in space, and has clear physical meaning.展开更多
Local measurement of plasma radial uniformity was performed in a dual frequency capacitively coupled argon plasma （DF-CCP） reactor using an optical probe. The optical probe collects the light emission from a small s...Local measurement of plasma radial uniformity was performed in a dual frequency capacitively coupled argon plasma （DF-CCP） reactor using an optical probe. The optical probe collects the light emission from a small separate volume in plasma, thus enabling to diagnose the plasma uniformity for different experimental parameters. Both the gas pressure and the low- frequency （LF） power have apparent effects on the radial uniformity of argon plasma. With the increase in either pressure or LF power, the emission profiles changed from a bell-shaped to a double-peak distribution. The influence of a fused-silica ring around the electrodes on the plasma uniformity was also studied using the optical probe. Possible reasons that result in nonuniform plasmas in our experiments are discussed.展开更多
A synthesized cyclometalated palladium-azo complex was explored as a multifunctional probe for visual detection of SO2, H2S and NH3 in water. In acidic aqueous environment, the sensing solution underwent a sharp color...A synthesized cyclometalated palladium-azo complex was explored as a multifunctional probe for visual detection of SO2, H2S and NH3 in water. In acidic aqueous environment, the sensing solution underwent a sharp color change from poor violet to deep blue when titrated with Na2SO3 standard solution. But the color changed from poor violet to bright yellow when titrated with Na2S standard solution. In basic environment, the sensing solution rapidly changed to magenta when titrated by NH4Cl-NH3 standard buffer solution at high concentration. However, the color of sensing solution changed to blue when titrated by NH4Cl-NH3 standard buffer solution at low concentration although the pH was kept constant during the titration. Different species of these hazardous gases at environmentally relevant concentration levels were differentiated by independent optical signal outputs, and the interference from other inorganic ions commonly existing in water was very small.展开更多
文摘This paper presents the measurement of void fraction in a vapor-liquid two-phase flow system constituted by horizontal heated tube bundles. An advanced measuring system with single-fiber optical probes is developed. The optical couplings are used in the measuring system instead of beam-splitting lens. Measurement of void fraction has been carried out within the tube bundles of the two-phase flow test section. The measurements show that the tube bundles have significant effect on the profile of the void fraction.
基金Supported by the National Science Foundation of China(No.59995460-1) and Nuclear Industry Science Foundation (No.Y7100E51001)
文摘Radial distribution of vapor local parameters, including local void fraction, interfacial velocity, bubblesize, bubble frequency and interfacial area concentration, are investigated through the measurement in an upwardboiling tube using dual-sensor optical probe. In addition, a new local parameter -"local bubble number concentra-tion" is developed on the basis of bubble frequency. The analysis shows that this parameter can reflect bubble numberdensity in space, and has clear physical meaning.
基金supported by National Natural Science Foundation of China (Nos. 10635010, 10975029)Beijing Key Laboratory of Printing & Packaging Materials and Technology of Beijing Institute of Graphic Communication of China (No. KF201004)
文摘Local measurement of plasma radial uniformity was performed in a dual frequency capacitively coupled argon plasma （DF-CCP） reactor using an optical probe. The optical probe collects the light emission from a small separate volume in plasma, thus enabling to diagnose the plasma uniformity for different experimental parameters. Both the gas pressure and the low- frequency （LF） power have apparent effects on the radial uniformity of argon plasma. With the increase in either pressure or LF power, the emission profiles changed from a bell-shaped to a double-peak distribution. The influence of a fused-silica ring around the electrodes on the plasma uniformity was also studied using the optical probe. Possible reasons that result in nonuniform plasmas in our experiments are discussed.
基金Project supported by the National Natural Science Foundation of China （No. 20275033） and the Natural Science Foundation of Fujian Province of China （No. 2006J0173）.
文摘A synthesized cyclometalated palladium-azo complex was explored as a multifunctional probe for visual detection of SO2, H2S and NH3 in water. In acidic aqueous environment, the sensing solution underwent a sharp color change from poor violet to deep blue when titrated with Na2SO3 standard solution. But the color changed from poor violet to bright yellow when titrated with Na2S standard solution. In basic environment, the sensing solution rapidly changed to magenta when titrated by NH4Cl-NH3 standard buffer solution at high concentration. However, the color of sensing solution changed to blue when titrated by NH4Cl-NH3 standard buffer solution at low concentration although the pH was kept constant during the titration. Different species of these hazardous gases at environmentally relevant concentration levels were differentiated by independent optical signal outputs, and the interference from other inorganic ions commonly existing in water was very small.
