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Trace Ammonia Detection Based on Near-Infrared Fiber-Optic Cantilever-Enhanced photoacoustic spectroscopy

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Photonic Sensors 2019年第4期9卷 293-301页

作者： Min GUO Ke CHEN Zhenfeng GONG Qingxu YU School of Optoelectronic Engineering and Instrumentation Science Dalian University of TechnologyDalian 116024China

A trace ammonia(NH3)detection system based on the near-infrared fiber-optic cantilever-enhanced photoacoustic spectroscopy(CEPAS)is proposed.A fiber-optic extrinsic Fabry-Perot interferometer(EFPI)based cantilever microphone has been designed to detect the photoacoustic pressure *** microphone has many advantages,such as small size and high sensitivity.A near-infrared tunable erbium-doped fiber laser(EDFL)amplified by an erbium-doped fiber amplifier(EDFA)is used as a photoacoustic excitation light *** improve the sensitivity,the photoacoustic signal is enhanced by a photoacoustic cell with a resonant frequency of 1624 *** the wavelength modulation spectroscopy(WMS)technique is applied,the weak photoacoustic signal is detected by the second-harmonic detection *** NH3 measurement experiments demonstrate that the designed fiber-optic CEPAS system has a linear response to concentrations in the range of 0 ppm‒20 ppm at the wavelength of 1522.448 ***,the detection limit is estimated to be 3.2 ppb for a lock-in integration time of 30 s.

关键词： Trace gas detection photoacoustic spectroscopy cantilever microphone fiber-optic Fabry-Perot interferometer near-infrared laser

Diurnal variation of aethalometer correction factors and optical absorption assessment of nucleation events using multi-wavelength photoacoustic spectroscopy

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Journal of Environmental Sciences 2019年第9期31卷 96-109页

作者： Tibor Ajtai Gergely Kiss-Albert Noemi Utry Adam Toth Andras Hoffer Gabor Szabo Zoltan Bozoki Department of Optics and Quantum Electronics University of Szeged H-6720 Szeged Hungary Hilase Development Production Service and Trading Limited Szekesfehervar H-8000 Hungary MTA-SZTE Research Group on photoacoustic spectroscopy H-6720 Szeged Hungary ELI-HU Non-Profit Ltd H-6720 Szeged Hungary Department of Earth and Environmental Sciences University of Pannonia P.O. Box 158 Veszprem H-8201 Hungary MTA-PE Air Chemistry Research Group P.O. Box 158 Veszprem H-8201 Hungary

A field measurement campaign was carried out during the late winter and early spring of2015 in Budapest, the capital of Hungary. The size distribution(SD) and optical absorption of carbonaceous particulate matter(CPM) was measured online using a Scanning Mobility Particle Sizer(SMPS), a 7λ-aethalometer and an inhouse developed 4λ-photoacoustic Spectrometer. Based on the SD data, the measurement period could be classified into days with and without new particle formation events(normal days and nucleation days),although particular nucleation-like events were observed on normal days as well. Three characteristic size modes were observed with CMDs of circa 15, 25 and 110 nm that corresponded to the nucleation, traffic and heating modes. Based on the temporal behavior of these modes both types of days were divided into distinctive daily periods(heating hours,traffic hours and nucleation hours). The optical absorption spectra(OAC and AAE) also displayed the same part of day behavior to that of SD. That way this paper is among the first to assess the optical response of urban nucleation events. Due to the simultaneous measurement of OAC by the 7λ-aethalometer and a 4λ-photoacoustic Spectrometer, OAC was measured overall at 11 wavelengths. That way aethalometer correction factors(f and C)were determined at all aethalometer wavelengths using in situ reference photoacoustic measurements. Correction factors were found to have both wavelength and time of the day variation. In the case of f, no clear trend could be observed, however, Cref values increased both as a function of wavelength.

关键词： photoacoustic spectroscopy Aerosol Angstr?m exponent Aethalometer Nucleation Size distribution

A quartz-enhanced photoacoustic spectroscopy sensor for measurement of water vapor concentration in the air

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Chinese Physics B 2015年第1期24卷 282-286页

作者：龚萍谢亮漆晓琼王瑞王辉常明超杨慧霞孙菲李冠鹏 State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of Sciences

A compact and highly linear quartz-enhanced photoacoustic spectroscopy（QEPAS） sensor for the measurement of water vapor concentration in the air is demonstrated. A cost-effective quartz tuning fork（QTF） is used as the sharp transducer to convert light energy into an electrical signal based on the piezoelectric effect, thereby removing the need for a photodetector. The short optical path featured by the proposed sensing system leads to a decreased size. Furthermore, a pair of microresonators is applied in the absorbance detection module（ADM） for QTF signal enhancement. Compared with the system without microresonators, the detected QTF signal is increased to approximately 7-fold. Using this optimized QEPAS sensor with the proper modulation frequency and depth, we measure the water vapor concentration in the air at atmospheric pressure and room temperature. The experimental result shows that the sensor has a high sensitivity of 1.058parts-per-million.

关键词： distributed feedback laser diode photoacoustic spectroscopy wavelength modulation second harmonic detection

Studies on Intermolecular Energy Transfer and Relaxation Processes in Solid Rare Earth Complexes by photoacoustic spectroscopy

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Journal of Rare Earths 2001年第3期19卷 181-186页

作者：伍荣护赵化章于锡娟宋慧宇苏庆德 Dept. of Chem. Univ. of Sci. and Technol. of China Hefei 230026 China

The photoacoustic spectra of Eu ( benz)(3) (.) ( phen)(2) ( benz: benzoate, phen: phenanthroline) and Eu-0.(8)Ln(0.2)(benz)(3)(.)(phen)(2)(Ln(3+) : La3+ or Nd3+) were reported. The intermolecular energy transfer processes were studied from the point of the nonradiative transitions. Combined with the fluorescence spectroscopy, photoacoustic spectroscopy reflects the variation of the luminescence efficiencies of solid samples. The luminescence efficiency increases when La3+ is introduced, but it decreases greatly when Nd3+ is added, which is due to the difference of intermolecular energy transfer processes. The models of intramolecular and intermolecular energy transfer and relaxation processes were established.

关键词： rare earths photoacoustic spectroscopy solid complexes variation of luminescence efficiencies intermolecular energy transfer

Study on F-F Transitions of Powdered Neodymium Compounds by photoacoustic spectroscopy

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Journal of Rare Earths 2002年第1期20卷 10-14页

作者：杨跃涛苏庆德赵贵文张淑仪 StateKeyLaboratoryofModernAcoustics InstituteofAcousticsNanjingUniversityNanjing210093 China DepartmentofChemistry UniversityofScienceandTechnologyofChinaHefei230026China

photoacoustic (PA) spectra of powdered neodymium oxide (Nd 2O 3 (A type)), neodymium hydrated chloride (NdCl 3·6H 2O) and neodymium fluoride (NdF 3) were reported. PA band shifts as compared to their positions in aqueous Nd 3+ are used to calculate the nephelauxetic parameters of the compounds. The variation of these parameters and correlation with the nature of metal ligand bonding were discussed. A novel method is introduced to determine the relative values of oscillator strengths and Judd Ofelt parameters of powdered samples using PA spectroscopy. It is found that a linear correlation exists between relative values of τ 2 and oscillator strengths of hypersensitive transitions of the title compounds. It is hopetul that the new method of PA technique may serve for the Judd Ofelt quantitative analysis of powdered rare earth compounds.

关键词： rare earths photoacoustic spectroscopy neodymium f f transition oscillator strength

Design and simulation of 1D longitudinal acoustic resonator for photoacoustic spectroscopy

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Design and simulation of 1D longitudinal acoustic resonator ...

Study on Dihydrated Praseodymium Acetylacetonate by photoacoustic Spectra with Broad Wavelength Range

2006 8th International Conference on Solid-State and Integrated Circuit Technology

作者： Jia Luo Xinming Ji Jianye Wang Jia Zhou Guoping Ru Yiping Huang ASIC ＆ System State Key Lab School of Microelectronics Fudan University

ISBN: (纸本)1424401607

＜正＞The design of acoustic resonator is critical for the sensitivity of photoacoustic（PA） gas *** this paper, a LC Circuit model is built for the simulation of 1D acoustic resonator with considerations of some nonideal factors such as the boundary layers in *** model is verified by the device and the corresponding experimental *** an application of the model,a 1D acoustic resonator for CO photoacoustic spectroscopy is studied. The effects of the structrual parameters,quality factor and resonant frequency on the performance of the device are theoretically ***’s worthy noted that for the first time we point out the effect of the ambient temperature.

关键词： ACOUSTIC RESONATORS photoacoustic spectroscopy boundary layer simulating resonant frequencies Experimental data

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Journal of Rare Earths 2003年第2期21卷 135-138页

作者：于锡娟伍荣护宋慧宇苏庆德 Department of Chemistry University of Science and Technology of China

The UV Vis, NIR and MIR photoacoustic spectra of Pr(aa) 3·2H 2O were measured and most f f transition peaks of Pr 3+ are detected. The peak split and peak shift are studied also. The covalency parameter is calculated and it turns out that the covalent bonds between Pr(Ⅲ) ions and ligands exist. The results conclude that photoacoustic spectroscopy offers a unique and complementary method in analysis of solid rare earth complexes. Compared with conventional FT IR transmission and absorption approaches, PAS has the advantages of fast, nondestructive analysis and high resolution.

关键词： organic chemistry f f transition rare earth acetylacetonates photoacoustic spectroscopy rare earth

Effects of pressure and noise on the stability of photoacoustic signals of trace gas components

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International Journal of Agricultural and Biological Engineering 2020年第5期13卷 187-193页

作者： Zhizhen Zhu Jing Luo Jiaxiang Liu Yonghua Fang Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Huaibei Normal University Huaibei 235000AnhuiChina

In essence,photoacoustic spectroscopy(PAS)technology is based on the thermal effect of gas infrared absorption and the acoustic theory of photoacoustic(PA)*** technology has a good application effect on environmental monitoring in *** this study,carbon monoxide and sulfur dioxide were used as examples to explain the potential application of PAS technology and analyze the influence mechanism of pressure and noise on the PA *** relationship between PA signal amplitude and the concentration of gas was determined by *** pressure and noise characteristics were experimentally studied,and the relationship between the PA signal and pressure&noise was *** theoretical analysis and experimental results not only provided a basis for further correction of the influence of pressure,noise and other factors on PA signal but also provided technical support for improving the field application of trace gas non-resonance PA detection device for environmental monitoring in agriculture.

关键词： photoacoustic spectroscopy environmental monitoring in agriculture trace gas pressure noise

photoacoustic Spectral Analysis of f-f Transitions of Neodymium Compounds with TFA and HFA

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Journal of Rare Earths 1998年第4期16卷 2-7页

作者：杨跃涛苏庆德赵贵文

The photoacoustic(PA) spectra of neodymium oxide, Nd 2O 3(A type), and trisfluoroacetylactone(TFA) and hexafluoroacetylactone(HFA) neodymium complexes, Nd(TFA) 3·2H 2O and Nd(HFA) 3·2H 2O, are reported. The nephelauxetic ratio β , bonding parameter b 1/2 , and Sinha parameter δ were calculated based on their PA spectra. The variation of these parameters and correlation of them with the nature of metal ligand bonding were discussed. The intensity analysis of PA bands of f f transitions of neodymium ion was carried out by calculating the intensity branching vector and the environmental effects on the f f transitions of neodymium ion were discussed also. The branching vectors of f f transition of Nd(TFA) 3·2H 2O and Nd(HFA) 3·2H 2O are similar, which indicates the perturbation of the two ligand fields is similar. As the oscillator strength of the hypersensitive transition increases, the branching vector exhibits a corresponding increase. The PA spectra provide a new tool for the study of the interaction between Ln 3+ ions and the environment.

关键词： Rare earths photoacoustic spectroscopy Neodymium f f transitions