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Energy consumption of electrooxidation systems with boron-doped diamond electrodes in the pulse current mode

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International Journal of Minerals,Metallurgy and Materials 2013年第1期20卷 106-112页

作者： jun-jun wei Xu-hui Gao Li-fu Hei Jawaid Askari Cheng-ming Li Institute of Advanced Materials and Technology University of Science and Technology Beijing Institute of Manufacturing Engineering National University of Sciences & Technology (NUST)

A pulse current technique was conducted in a boron-doped diamond （BDD） anode system for electrochemical waste- water treatment. Due to the strong generation and weak absorption of hydroxyl radicals on the diamond surface, the BDD elec- trode possesses a powerful capability of electrochemical oxidation of organic compounds, especially in the pulse current mode. The influences of pulse current parameters such as current density, pulse duty cycle, and frequency were investigated in terms of chemical oxygen demand （COD） removal, average current efficiency, and specific energy consumption. The results demon- strated that the relatively high COD removal and low specific energy consumption were obtained simultaneously only if the current density or pulse duty cycle was adjusted to a reasonable value. Increasing the frequency slightly enhanced the COD re- moval and average current efficiency. A pulse-BDD anode system showed a stronger energy saving ability than a constant-BDD anode system when the electrochemical oxidation of phenol of the two systems was compared. The results prove that the pulse current technique is more cost-effective and more suitable for a BDD anode system for real wastewater treatment. A kinetic analysis was presented to explain the above results.

关键词： diamond fihlls boron doping electrochemical oxidation hydroxyl radicals energy consumption wastewater treat- ment

Optical characterization of single-crystal diamond grown by DC arc plasma jet CVD

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International Journal of Minerals,Metallurgy and Materials 2017年第12期24卷 1424-1430页

作者： Li-fu Hei Yun Zhao jun-jun wei Jin-long Liu Cheng-ming Li Fan-xiu Lü Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China

Optical centers of single-crystal diamond grown by DC arc plasma jet chemical vapor deposition(CVD) were examined using a low-temperature photoluminescence(PL) technique. The results show that most of the nitrogen-vacancy(NV) complexes are present as NV-centers, although some H2 and H3 centers and B-aggregates are also present in the single-crystal diamond because of nitrogen aggregation resulting from high N_2 incorporation and the high mobility of vacancies under growth temperatures of 950–1000°C. Furthermore, emissions of radiation-induced defects were also detected at 389, 467.5, 550, and 588.6 nm in the PL spectra. The reason for the formation of these radiation-induced defects is not clear. Although a Ni-based alloy was used during the diamond growth, Ni-related emissions were not detected in the PL spectra. In addition, the silicon-vacancy(Si-V)-related emission line at 737 nm, which has been observed in the spectra of many previously reported microwave plasma chemical vapor deposition(MPCVD) synthetic diamonds, was absent in the PL spectra of the single-crystal diamond prepared in this work. The high density of NV-centers, along with the absence of Ni-related defects and Si-V centers, makes the single-crystal diamond grown by DC arc plasma jet CVD a promising material for applications in quantum computing.

关键词： diamond single crystals direct current arc plasma jet chemical vapor deposition photoluminescence optical spectra

Enhanced deposition of Zn O films by Li doping using radio frequency reactive magnetron sputtering

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International Journal of Minerals,Metallurgy and Materials 2015年第10期22卷 1108-1114页

作者： Liang-xian Chen Sheng Liu Cheng-ming Li Yi-chao Wang Jin-long Liu jun-jun wei Institute for Advanced Materials and Technology University of Science and Technology Beijing School of Electrical and Computer Engineering RMIT University

Radio frequency(RF) reactive magnetron sputtering was utilized to deposit Li-doped and undoped zinc oxide(Zn O) films on silicon wafers. Various Ar/O2 gas ratios by volume and sputtering powers were selected for each deposition process. The results demonstrate that the enhanced Zn O films are obtained via Li doping. The average deposition rate for doped Zn O films is twice more than that of the undoped films. Both atomic force microscopy and scanning electron microscopy studies indicate that Li doping significantly contributes to the higher degree of crystallinity of wurtzite–Zn O. X-ray diffraction analysis demonstrates that Li doping promotes the(002) preferential orientation in Li-doped Zn O films. However, an increase in the Zn O lattice constant, broadening of the(002) peak and a decrease in the peak integral area are observed in some Li-doped samples, especially as the form of Li2 O. This implies that doping with Li expands the crystal structure and thus induces the additional strain in the crystal lattice. The oriented-growth Li-doped Zn O will make significant applications in future surface acoustic wave devices.

关键词： zinc oxide thin films doping deposition magnetron

Orientation variation along growth direction of millimeter free-standing CVD diamond thinned by mechanical grinding

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International Journal of Minerals,Metallurgy and Materials 2014年第8期21卷 839-844页

作者： Xing-kai Wen jun-jun wei Jin-long Liu Jian-chao Guo Liang-xian Chen Cheng-ming Li Institute of Advanced Materials and Technology University of Science and Technology Beijing

A free-standing diamond film with millimeter thickness prepared by DC arc plasma jet was thinned successively by mechanical grinding. The orientation and quality of the diamond films with different thicknesses were characterized by X-ray diffraction and Raman spectroscopy, respectively. The results show a random grain-orientatinn distribution during the initial growth stage. As the film thickness increases, the preferred orientation of the diamond film changes from （111） to （220）, due to the competitive growth mechanism. Twinning generated during the nucleation stage appears to stabilize the preferential growth along the 〈110〉 direction. The interplanar spacing of the （220） plane is enlarged as the film thickness increases, which is caused by the increase of non-diamond-phase carbon and impurities under the cyclic gas. In addition, the quality of the diamond film is barely degraded during the growth process. Furthermore, the peak shift demonstrates a significant inhomogeneity of stress along the film growth direction, which results from competitive growth.

关键词： diamond films chemical vapor deposition grinding orientation growth mechanisms quality

Dispersion of ZnO Nanocrytals in Co-solvent and Its Application in Photovoltaic Material

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Chemical Research in Chinese Universities 2011年第6期27卷 906-909页

作者： CHEN Shao-jie ZHANG Qiu-yu ZHANG jun-ping GU jun-wei ZHOU Jian SHI You-qiang Key Laboratory of Space Materials Science and Technology Ministry of Education School of Science Northwestern Polytechnical University Xi＇an 710129 P. R. China

To overcome the aggregation of nanocrystals in a blend of inorganic material with conjugated polymers to prepare photovoltaic material, we used a co-solvent blend of CHCl3 with MeOH at a certain volume fraction to disperse inorganic nanocrystals. The results show that when the volume fraction of MeOH is 50%, ZnO nanocrystals with an average diameter of 30 nm disperse well in the co-solvent solution. Its application in photovoltaic material was investigated in this work, and the photoluminescence（PL） spectra show that when ZnO was 50%（volume fraction） in solution and 25%（volume fraction） in film, the fluorescence quenching reached the maximum values 83.34% and 64.4%, respectively, indicating that electron could transfer from conjugated polymer to electron-acceptor ZnO effectively.

关键词： ZnO nanocrystal Dispersion Co-solvent Photovoltaic material

Surface Carbonization of GaN and the Related Structure Evolution during the Annealing Process

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Chinese Physics Letters 2018年第1期35卷 51-54页

作者： Jin-Long Liu Liang-Xian Chen jun-jun wei Li-Fu Hei Xu Zhang Cheng-Ming Li Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083 Institute of Low Energy Nuclear Physics Beijing Normal UniversityBeijing Radiation CenterBeijing 100875

To explain the stabilization mechanism of the carbon-ion-implanted GaN under the diamond growth environment,the luminescence characteristics and structure evolution correlative with sites'carbon atoms located for highfluence carbon-ion-implanted Ga N are *** is implanted with carbon ion using fluence of 2×10^(17)cm^(-2)and energy of 45 *** the implanted samples are annealed at 800℃for 20 min and 1 h under the N_(2) *** luminescence characteristics of carbon-ion-implanted GaN are evaluated by photoluminescence spectrum at wavelength 325 *** lattice damage of Ga N is characterized by Raman spectrum and the corresponding vacancy-defect evolution before and after annealing is measured by slow positron *** results show that most of the carbon atoms will be located at the interstitial sites after carbon ion implantation due to the weak *** the implanted samples are annealed,strong yellow luminescence is emitted and the vacancies for Ga(V_(Ga))are reduced resulting from the migration of interstitial carbon(C_(i))and formation of complexes(CGaand/or C_(Ga)-C_(i))between *** the annealing time is prolonged,the carbon ions accommodated by the vacancies are saturated,vacancy clusters with carbon atoms appear and the concentration of C_(Ga)diminishes,which will have an adverse effect on the diamond film nucleation and growth.

关键词： Gallium nitride

Comparison of α particle detectors based on single-crystal diamond films grown in two types of gas atmospheres by microwave plasma-assisted chemical vapor deposition

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International Journal of Minerals,Metallurgy and Materials 2020年第5期27卷 703-712页

作者： Yan-zhao Guo Jin-long Liu Jiang-wei Liu Yu-ting Zheng Yun Zhao Xiao-lu Yuan Zi-hao Guo Li-fu Hei Liang-xian Chen jun-jun wei Jian-peng Xing Cheng-ming Li Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China Optical and Electronic Materials Unit National Institute for Materials Science(NIMSIbaraki 305-0044Japan Key Laboratory of Microelectronic Device and Integration Technology Institute of Microelectronics of the Chinese Academy of SciencesBeijing 100029China

Chemical vapor deposition(CVD)-grown diamond films have been developed as irradiation-resistant materials to replace or upgrade current detectors for use in extreme radiation environments. However, their sensitivity in practical applications has been inhibited by space charge stability issues caused by defects and impurities in pure diamond crystal materials. In this study, two high-quality CVD-grown single-crystal diamond(SCD) detectors with low content of nitrogen impurities were fabricated and characterized. The intrinsic properties of the SCD samples were characterized using Raman spectroscopy, stereomicroscopy, and X-ray diffraction with the rocking curve mode, cathode luminescence(CL), and infrared and ultraviolet-visible-near infrared spectroscopies. After packaging the detectors, the dark current and energy resolution under α particle irradiation were investigated. Dark currents of less than 5 pA at 100 V were obtained after annealing the electrodes, which is comparable with the optimal value previously reported. The detector that uses a diamond film with higher nitrogen content showed poor energy resolution, whereas the detector with more dislocations showed poor charge collection efficiency(CCE). This demonstrates that the nitrogen content in diamond has a significant effect on the energy resolution of detectors, while the dislocations in diamond largely contribute to the poor CCE of detectors.

关键词： single-crystal diamond nitrogen impurity detector αparticle

Preparation and Identification of Monoclonal Antibodies against Chicken Immunoglobulin G

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Animal Husbandry and Feed Science 2010年第10期2卷 26-27页

作者： WANG jun-jun YU wei-yi Key Laboratory of Zoonoses of Anhui Province Anhui Agricultural University Hefei 230036 China

[ Objective] To prepare monoclonal antibodies against chicken immunoglobulin G （IgG） and improve the diagnostic level of specific antibodies in chickens. [ Method] Chicken IgG was isolated by saturated ammonium sulfate and purified by Sephadex G-200 column chromatography. Then the BALB/c mice were immunized by the chicken IgG, and the spleen cells were fused with mouse myeloma cells SP2/0. Finally, the positive hybridoma cells were screened and detected by indirect enzyme-linked immunosorbent assay （ELISA）. [ Result] Four hybridoma cell strains secre- ting monoclonal antibodies against chicken IgG were obtained and named as C44, C45, C67 and C68, and their ascites titers in indirect ELISA were 1 ： 640 000, 1 ： 320 000, 1 ： 640 000 and 1 ： 80 000, respectively. The monoclonal antibodies secreted by C44 and C45 could recognize light chains of chicken IgG and those secreted by C,67 and C68 could recognize heavy chains of chicken IgG. They all could not recognize IgG from duck, rabbit and swine. Additionally, the Ig type identification results showed that they all belonged to IgGl. [ Conclusion] Four cell strains of obtained hybridoma can stably produce the monoclonal antibodies against chicken IgG.

关键词： Chicken IgG Monoclonal antibody. SPecificity. Identification

Effects of electroacupuncture at 2 and 100 Hz on rat type 2 diabetic neuropathic pain and hyperalgesia-related protein expression in the dorsal root ganglion

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2017年第3期18卷 239-248页

作者： Xiao-fen HE jun-jun wei Sheng-yun SHOU Jian-qiao FANG Yong-liang JIANG Department of Neurobiology and Acupuncture Research the Third Clinical Medical College Zhejiang Chinese Medical University Hangzhou 310053 China Zhejiang Chinese Medical University Hangzhou 310053 China

Objective： To investigate the analgesic effects of electroacupuncture （EA） at 2 and 100 Hz on type 2 diabetic neuropathic pain （DNP） and on the expressions of the P2X3 receptor and calcitonin gene-related peptide （CGRP） in the dorsal root ganglion （DRG）. Methods： Rat type 2 DNP was induced by a high calorie and high sugar diet fed for 7 weeks, plus a single intraperitoneal injection of streptozotocin （STZ） after 5 weeks. EA at 2 and 100 Hz was carried out once every day after 7 weeks for 7 consecutive days. Body weight, serum fasting insulin （FINS）, fasting blood glucose （FBG）, insulin sensitivity index （ISI）, and paw withdrawal latency （PWL） were measured. The expressions of L4-L6 DRG P2X3 receptors and CGRP were assessed by immunofluorescence. Results： Type 2 DNP was successfully induced as shown by the increased body weight, FINS, and FBG, as well as the reduced ISI and PWL. Expressions of P2X3 receptors and CGRP in L4-L6 DRGs increased. EA at both 2 and 100 Hz relieved type 2 DNP, but the analgesic effect of EA was stronger at 2 Hz. P2X3 receptor expression decreased in L4-L6 DRGs following EA at 2 Hz and in L5 and L6 DRGs following EA at 100 Hz. EA at both 2 and 100 Hz down-regulated CGRP overexpression in L4-L6 DRGs. Conclusions： These findings indicate that EA at 2 Hz is a good option for the management of type 2 DNP. The EA effect may be related to its down-regulation of the overexpressions of the DRG P2X3 receptors and CGRP in this condition.

关键词： Electroacupuncture Type 2 diabetic neuropathic pain Dorsal root ganglion P2X3 receptor Calcitoningene-related peptide