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Advanced Functional Materials 03/2009; 19(9):1444 - 1450. · 10.18 Impact Factor
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ABSTRACT: ZnS nanocrystals are less toxic than cadmium chalcogenide materials, which might have more applications in biological detection. Yet more excitation energy during its electrochemiluminescence (ECL) process should be applied because of the wide energy gap (3.7 eV) of ZnS. Here, ECL of ZnS doped with Mn2+ nanocrystals (ZnS:Mn2+ NCs) modified on glassy carbon electrode was investigated in aqueous solution with the coreactant hydrogen peroxide (H2O2) for the first time. Besides the ECL process of pure ZnS NCs at a negative potential of more than −2.0 V vs SCE, a new ECL emission peak was observed at ca. −1.50 V vs SCE on the ZnS:Mn2+ NCs-modified glassy carbon electrode in pH 9.0 phosphate buffer solution. This new ECL emission was attributed to the excited state of Mn2+ lying in the Zn2+ sites. The concentration of Mn2+ doped in ZnS NCs played a key role in this new ECL process. Furthermore, this specific ECL emission was dependent on the concentration of H2O2. The largely decreased excitation energy of this new ECL emission would promote the application of doped ZnS NCs in the fields of biological and environmental analysis without the interference of hydrogen bubble in the ECL process.
10/2008;
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ABSTRACT: We report on the preparation of dendritic CdO nanofilms on glassy carbon surfaces for the first time. Our approach is based on the controlled-potential electrodepositin of Cd and followed by the spontaneous oxidation of the resulting nanoscaled Cd films. In the process, the initial metal Cd films are growing from an electrolyte solution containing CdCl2 and 3-mercaptopropionic acid (MPA) under designed experimental conditions. The formed nanoscaled Cd films can easily react with oxygen and are transformed into nanostructured CdO in air. The resulting films are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) techniques. The results reveal that MPA, pH of solution, deposition potential, and time play key roles in the formation of dendritic nanostructures. Electrogenerated chemiluminescence (ECL) properties of CdO nanostructures are examined and compared. The dendritic CdO nanostructure film materials show stable and strong ECL emission in aqueous solution with the co-reactant K2S2O8.
04/2008;
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ABSTRACT: A non-linear algorithm, polynomial PLS was applied to the simultaneous analysis of OP-FTIR spectra of a five-component system whose FTIR spectra were seriously overlapped. The results were compared with the one obtained from PLS. PPLS yielded good performance, especially for the prediction of benzene and chloroform. RMSEP (root mean squared error of prediction) of benzene and chloroform in PPLS model were 0.043 and 0.087 and the corresponding values in PLS were 0.402 and 0.842, respectively. Meanwhile, variance was accounted by PPLS with fewer latent variables, which indicates the simplicity and robustness of the model. The successful application of PPLS to non-linear system was meaningful for the use of remote sensing FTIR in air monitoring.
Guang pu xue yu guang pu fen xi = Guang pu 05/2006; 26(4):620-3. · 0.84 Impact Factor
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ABSTRACT: The flame temperature of three kinds of solid propellants was measured by passive remote sensing FTIR with the resolution of 1 cm(-1). These three kinds of solid propellants are adulterate nano-scale metal oxide particles, adulterate normal metal oxide particles, and propellant without any adulterations. The main components of the solid propellant are nitrocellulose and nitroglycerin. The metallic oxides, including 6 nm CuO, 56 nm Fe2O3, 16 nm NiO, and correspondingly the normal particles, were adulterated into the solid propellants respectively. The flame temperature was calculated through the fine structure of the emission fundamental band of H2O at 2.75 microm. The results of the flame temperature of the solid propellants adulterating nano-scale CuO, Fe2O3 and NiO are 3089, 3193 and 3183 K, respectively. The temperatures of the three kinds of solid propellants were compared, and it was shown that there is no obvious difference in the flame temperature among the three kinds of solid propellants.
Guang pu xue yu guang pu fen xi = Guang pu 04/2006; 26(3):441-3. · 0.84 Impact Factor
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ABSTRACT: In order to obtain infrared spectral radiance distribution of some infrared sources, such as spectral radiant flux density, spectral radiant intensity, spectral radiance and spectral irradiance, the instrument response function under different conditions must be known. In the present paper, the calibration of instrument response function during passive FTIR measurement has been discussed. The experimental results illustrate that under different experimental conditions, the instrument response function varies not only with the temperature of the blackbody but also with the signal amplitude received by the infrared instrument. So, during passive FTIR measurement, the temperature and the emission signal amplitude of the source must be observed carefully in order to get satisfactory instrument response function.
Guang pu xue yu guang pu fen xi = Guang pu 02/2006; 26(1):45-6. · 0.84 Impact Factor
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ABSTRACT: Quantitative analysis of FTIR spectra, which are seriously overlapped in the spectral bands, was studied by artificial neural networks. The optimum network was chosen by a new criterion, i. e. the degree of approximation. After the network was established, two kinds of spectra were resolved. It was demonstrated that accurate results could be obtained when two components were both included. In addition, the unknown spectrum could be identified and quantified. It was showed that the artificial neural network has excellent non-linear ability of solution. Meanwhile, the method provides an efficient approach to the identification and quantification of the unknown samples.
Guang pu xue yu guang pu fen xi = Guang pu 02/2006; 26(1):51-3. · 0.84 Impact Factor
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ABSTRACT: Partial least squares(PLS) algorithm is an effective chemometric tool. It takes the advantages of multipal linear regression (MLR) and principal component regression (PCR), which makes Fourier transform infrared spectrometry (FTIR) more powerful and useful. Accompanied with increasing use of FTIR, the algorithm is modified and corrected under different circumstances. The applications of PLS to FTIR were mentioned. Improved algorithms were presented, such as moving windows PLS(MWPLS), robust PLS (RPLS), weighted PLS(WPLS), and non-linear PLS. Data pre-processing, selection of variable, noise elimination and non-linear model of PLS were introduced.
Guang pu xue yu guang pu fen xi = Guang pu 11/2005; 25(10):1610-3. · 0.84 Impact Factor
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ABSTRACT: As an OP-FTIR(Open Path FTIR) technology, passive OP-FTIR not only has the advantages of OP-FTIR, but also has the ability to collect data from any direction without prior background information. This technology allows mobile, fast, man-held and stand-off detection of hazardous chemical cloud.The present paper presents some developments of passive OP-FTIR, including high altitude atmospheric pollution detection, auto-detection of toxic cloud, hot gases detection (such as the determination of major combustion products in aircraft exhausts, remote sensing of smoke plumes, and remote sensing of volcano emissions), temperature and combustion products determination (including cloud temperature determination). The present paper also gives the application of passive OP-FTIR in the military. With the development of FTIR and computer science, more and more applications of OP-FTIR to environment supervision, aviation and space flight, engine exhausts, combustion and military will be fulfilled.
Guang pu xue yu guang pu fen xi = Guang pu 11/2005; 25(10):1614-7. · 0.84 Impact Factor
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ABSTRACT: A series of lanthanide complexes Ln(tfnb)3dafone, Ln(hfth)3dafone and Ln(pfnd)3dafone (Ln = Er, Nd and Yb) with fluorinated-ligand 1-(2-naphthyl)-4,4,4-trifluoro-1,3-butanedionate (Htfnb), 4,4,5,5,6,6,6-heptafluoro-1-(2-thienyl)hexane-1,3-dione (Hhfth) and 4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-pentadecafluoro-1-(naphthalen-2-yl)decane-1,3-dione (Hpfnd) served as main sensitizers, respectively, and 4,5-diazafluoren-9-one (dafone) as the synergistic ligand were synthesized. Upon excitation at the maximum absorption of the ligands, the complexes all show the characteristic near-infrared (NIR) luminescence of the corresponding Ln3+ ions, which is due to efficient energy transfer from the ligands to the central Ln3+ ions via an antenna effect. Moreover, an indirect excitation model is proposed and the influence of ligands on the luminescence properties of the complexes is further discussed.
Journal of Photochemistry and Photobiology A: Chemistry.
