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Two-dimensional spectral images are generally distorted. Spectrum extraction operation is affected by such distortion, which reduces the quality of one-dimensional spectral data. Aiming at above problem, an effective correction method for the distorted two-dimensional spectral images based on neural network is proposed. Firstly, by extracting the center line of each fiber from the flat-field spectrum and fitting the equal-wavelength line at each specific wavelength from the calibration lamp spectrum, data that represent distortion characteristics from two-dimensional spectral images can be obtained. The training samples are thus constructed according to these two sets of feature lines. Secondly, a neural network model is then designed and trained to fit the relation between the pixel coordinates of the image before and after correction. Therefore, all pixel coordinate values of the corrected image can be calculated by the model. Finally, the flux values of the corrected image are filled one-to-one in accord with the flux value of the original distorted image. The correction experiments are carried out with the flat-field spectrum, calibration lamp spectrum, and object spectrum respectively. The spectral extraction results of the object spectrum before and after correction are compared. Experimental results prove that the method can correct the distorted two-dimensional spectral image effectively and improve quality of one-dimensional spectral data to an extent.

Novel cooperative ZnS–CdSe@Co/N–C core/shell composites were successfully prepared by the chelation of CoCl2 on the surface of ZnS–CdSe nanoparticles and further modification by N-doped carbon spheres. These composites possessed a heterojunction and cocatalyst properties and can reduce the energy band, promote the activity and selectivity, and enhance the catalyst service life. Therefore these composites may offer a new strategy to regulate the optical absorption and photocatalytic properties of semiconductor materials. [ABSTRACT FROM AUTHOR]

A luminescence sensor based on an europium(III)-based lanthanide–organic framework, [Eu(BCB)(DMF)]·(DMF)1.5(H2O)2 (1), was synthesized via a solvothermal method using 4,4′,4′′-benzenetricarbonyltribenzoic acid (H3BCB) as a bridging ligand. Single-crystal X-ray diffraction indicates that Eu centers are eight-coordinated with a trigonal dodecahedron and a square antiprismatic configuration, and adjacent Eu atoms are bridged by BCB organic linkers to form a 3D rod-packing structure. Photoluminescence studies show that compound 1 emits bright red luminescence and behaves as a multi-responsive luminescent sensor toward 4-nitrophenol (4-NP) and I− and Fe3+ ions in water with high sensitivity, selectivity and low detection limits. Furthermore, the possible luminescence sensing mechanisms were also investigated by PXRD analysis, UV-vis spectroscopy and X-ray photoelectron spectroscopy (XPS). The recognition mechanism for 4-NP and I− ions can be attributed to the competition absorption and that for Fe3+ ions is considered to be a multi-quenching mechanism dominated by competition absorption. This study demonstrates that the lanthanide-based MOF might be a promising candidate for the detection of 4-NP and I− and Fe3+ ions in aqueous medium. [ABSTRACT FROM AUTHOR]

Recently, the microwave‐assisted heating method has become a commonly used and environmentally friendly heating technology in the field of organic and polymeric synthetic chemistry. A series of poly(5,5‐dimethyl trimethylenecarbonate‐co‐2‐phenyl‐5,5‐bis[oxymethyl] trimethylenecarbonate) (P[DTC‐co‐PTC]) were synthesized by microwave‐assisted ring‐opening polymerization of 5,5‐dimethyl trimethylene carbonate (DTC) and 2‐phenyl‐5,5‐bis(oxymethyl) trimethylene carbonate (PTC) using tin(II) 2‐ethylhexanoate and aluminum isopropoxidase, the catalysts. These co‐polycarbonates were further reduced by a palladium‐carbon catalyst (Pd/C catalyst, 10%) to make partly deprotected polycarbonates (HPDPC). These two co‐polycarbonates were characterized by gel permeation chromatography, 1HNMR, Fourier transform infrared spectroscopy, UV, differential scanning calorimetry, and automatic contact‐angle measurements. The influences of the microwave irradiation time, microwave power, monomer feed molar ratio, different catalysts, and monomer/catalyst feed molar ratio on the molecular weights of co‐polycarbonates were also investigated. In vitro water absorption, degradation and drug release tests indicated that partly deprotected co‐polycarbonate HPDPC possessed greater hydrophilicity, faster degradation rate, and faster drug release rate than that of corresponding P(DTC‐co‐PTC). Therefore, microwave‐assisted polymerization is a clean and cheap heating method and can be used for ring‐opening copolymerization of carbonates, which enhances the hydrophilicity and biodegradation rate of aliphatic polycarbonates. [ABSTRACT FROM AUTHOR]

Novel cooperative ZnS–CdSe@Co/N–C core/shell composites were successfully prepared by the chelation of CoCl2 on the surface of ZnS–CdSe nanoparticles and further modification by N-doped carbon spheres. These composites possessed a heterojunction and cocatalyst properties and can reduce the energy band, promote the activity and selectivity, and enhance the catalyst service life. Therefore these composites may offer a new strategy to regulate the optical absorption and photocatalytic properties of semiconductor materials. [ABSTRACT FROM AUTHOR]

A luminescence sensor based on an europium(III)-based lanthanide-organic framework, [Eu(BCB)(DMF)]·(DMF) 1.5 (H 2 O) 2 (1), was synthesized via a solvothermal method using 4,4',4''-benzenetricarbonyltribenzoic acid (H 3 BCB) as a bridging ligand. Single-crystal X-ray diffraction indicates that Eu centers are eight-coordinated with a trigonal dodecahedron and a square antiprismatic configuration, and adjacent Eu atoms are bridged by BCB organic linkers to form a 3D rod-packing structure. Photoluminescence studies show that compound 1 emits bright red luminescence and behaves as a multi-responsive luminescent sensor toward 4-nitrophenol (4-NP) and I - and Fe 3+ ions in water with high sensitivity, selectivity and low detection limits. Furthermore, the possible luminescence sensing mechanisms were also investigated by PXRD analysis, UV-vis spectroscopy and X-ray photoelectron spectroscopy (XPS). The recognition mechanism for 4-NP and I - ions can be attributed to the competition absorption and that for Fe 3+ ions is considered to be a multi-quenching mechanism dominated by competition absorption. This study demonstrates that the lanthanide-based MOF might be a promising candidate for the detection of 4-NP and I - and Fe 3+ ions in aqueous medium.