Publications by authors named "Zhang Xi-qing"

Article Synopsis
  • A new method was developed to detect 107 pesticide residues in wolfberries, showing strong validation through tests on precision, stability, and accuracy.
  • The method achieved low limits of detection (0.14-1.91 µg/kg) and consistently good recovery rates of pesticide analytes across different concentrations.
  • Analysis of 50 wolfberry samples from various sources revealed that all samples contained pesticides, with 26 different residues found, prominently featuring insecticides like acetamiprid and imidacloprid.
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This study developed a synbiotic food through the fermentation of whole oat flour with Lactobacillus plantarum TK9 and Bifidobacterium animalis subsp. lactis V9. The physicochemical properties, changes in ingredients and peptide molecular weight distributions were determined during the whole oat fermentation.

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We have fabricated an organic deep ultraviolet photodetector (PD) using PEDOT:PSS (PH 1000) as a transparent anode. NPB and PBD were employed as electron donor and acceptor, respectively. The PD exhibits a dark current of 0.

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Using high temperature solid state reaction method, ZnO and Ga2O3 with high purity as raw materials, different ZnGa2O4 samples were prepared at different molar ratios of raw materials and different temperatures. After excitation of the ZnGa2O4 samples by 254 nm UV lamps, obvious long lasting luminescence was detected for the first time, which showed two new long lasting luminescence peaks at 505 nm and 690 nm, respectively. And the relative intensity of the two peaks was effected by the preparation conditions such as molar ratio of the two raw materials and the sintering temperature.

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High-quality ZnO thin films were grown by plasma-assisted molecular beam epitaxy (P-MBE) on Al2 O3 (0001) substrate with a low temperature ZnO buffer layer. Structural and optical characterization were studied for ZnO thin films. Only a peak at (0002) were observed in the X-ray reflectivity (XRD) spectra with the full-width at half maximum (FWHM) value 0.

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  • CdS thin films were created using a chemical bath deposition method at 90°C, and their properties were analyzed through different treatments, namely annealing and CdCl2 treatment.
  • XRD and SEM techniques revealed that untreated films had poor crystallinity, whereas annealed films showed cubic crystallinity but with small grain sizes; CdCl2 treatment improved crystallinity and resulted in a smoother surface.
  • Optical studies indicated that the energy gap of the films decreased with annealing, and the CdCl2 treated films had fewer defects, leading to enhanced properties overall.
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  • Researchers grew nano-sized ZnO embedded in SiO2 layers using radio-frequency magnetron sputtering.
  • The optical properties were analyzed through absorption and PL (Photoluminescence) spectra at room temperature, showing a blue shift in absorption as the size of ZnO decreased, indicating a stronger quantum size effect.
  • PL spectra revealed two emission peaks at 387 nm (UV emission from free-excitons) and 441 nm (blue emission from oxygen vacancy transitions), with further confirmation from time-resolved spectra and luminescence decay curves.
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  • The study explored how mechanical surface treatments of indium-tin-oxide (ITO) anodes affect OLED device performance.
  • Researchers used atomic force microscopy (AFM) to analyze the surface morphology, finding a reduction in spike size and number, which improved the ITO's regulation.
  • As a result of these treatments, the brightness and efficiency of OLED devices significantly increased, demonstrating the effectiveness of this novel method.
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300 nm thick aluminum films were deposited on SiO2 substrates by heat evaporation. At 0 degrees C, 40 V DC voltage, the authors successfully prepared high density Al2O3 films by anodic oxidation on SiO2 substrates with 15 wt% H2SO4 as electrolyte, and AFM was employed to study the film surface morphology. At room temperature the authors measured the photoluminescence spectrum of Al2O3 films prepared at different anodic voltages excited by Xe lamp.

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A new rare earth complex Tb(BSA)4 was synthesized and studied. Pure green and narrow band emission was generated from the device with structure ITO/PVK:Tb(BSA)4 /Alq3 /LiF/Al, where PVK was used to improve the film-formation and hole-transport property of the Tb(BSA)4. The absorption mechanism, and the photoluminescence and electroluminescence mechanisms are discussed.

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An organic photovoltaic(PV) cell, ITO/MEH-PPV/Alq3/LiF/Al, was fabricated. The MEH-PPV and Alq3 are the electron-acceptor and donor in the cell, respectively. The respond region matchs the adsorption of Alq3 film.

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Pure green and narrowbandwidth emission from an organic electroluminescent device was presented by using arare earth terbium (III) complex as the emissive layer. The structure of the device was ITO/PVK/Tb/PBD/LiF/Al. It was proved that this new kind of rare earth complex has excellent photoluminescent and electroluminescent properties.

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ZnO thin films were deposited by magnetron sputtering on SiQ2 substrates. The temperature dependence of the absorption spectra and the photoluminescence spectra was studied for ZnO thin film. The absorption of the longitudinal optical (LO) phonons and the free-excitons was observed at room temperature.

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ZnO thin film is a promising material for short-wave laser and LED etc, due to its high excition binding energy, intense stimulated emission, low lasing threshold, and high working temperature. ZnO thin films were prepared by laser molecular beam epitaxy (L-MBE) in our work. At room-temperature we reported the measurements of absorption spectra and emission spectra of ZnO thin films excited by various optical pumping intensities.

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