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7篇 您的检索式:作者名="Junqi Du"
    题名 作者 年代 出处 被引量
1Efficient aerobic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid on Ru/C catalysts显示文摘2,5-Furandicarboxylic(FDCA) is a potential substitute for petroleum-derived terephthalic acid, and aerobic oxidation of5-hydroxymethylfurfural(HMF) provides an efficient route to synthesis of FDCA. On an activated carbon supported ruthenium(Ru/C) catalyst(with 5 wt% Ru loading), HMF was readily oxidized to FDCA in a high yield of 97.3% at 383 K and 1.0 MPa O_2 in the presence of Mg(OH)_2 as base additive. Ru/C was superior to Pt/C and Pd/C and also other supported Ru catalysts with similar sizes of metal nanoparticles(1–2 nm). The Ru/C catalysts were stable and recyclable, and their efficiency in the formation of FDCA increased with Ru loadings examined in the range of 0.5 wt%–5.0 wt%. Based on the kinetic studies including the effects of reaction time, reaction temperature, O_2 pressure, on the oxidation of HMF to FDCA on Ru/C, it was confirmed that the oxidation of HMF to FDCA proceeds involving the primary oxidation of HMF to 2,5-diformylfuran(DFF) intermediate, and its sequential oxidation to 5-formyl-2-furancarboxylic acid(FFCA) and ultimately to FDCA, in which the oxidation of FFCA to FDCA is the rate-determining step and dictates the overall formation rate of FDCA. This study provides directions towards efficient synthesis of FDCA from HMF, for example, by designing novel catalysts more efficient for the involved oxidation step of FFCA to FDCA.Lufan Zheng Junqi Zhao Zexue Du Baoning Zong Haichao Liu 2017Science China Chemistry2017,60,7:8
2Degradation of simulated organic wastewater by advanced oxidation with oxidants generated from oxygen reduction显示文摘The degradation capacity of advanced oxidants generated from oxygen reduction was investigated in model effluent containing chlorobenzene, aniline and benzene through the advanced oxidation processes(AOPs). Intermediate products of the degradation process were determined by GC–MS, and they contributed to specify the degradation pathways of monoaromatic compounds. The study particularly focused on the influence of the dosage of the oxidant, pH and the initial concentration of organic compounds on the degradation effectiveness.When the dosage of oxidant was 4 wt% and the pH was 7, the maximum degradation rates of 74.83% chlorobenzene, 70.32% aniline and 37.69% benzene were achieved. Furthermore, microwave was applied to intensify the oxidation process under optimal operation conditions, and the degradation rates were increased to 87.85% chlorobenzene, 89.11% aniline and 39.03% benzene, respectively.Yi Ouyang Qing Xu Yang Xiang Wei Liu Junqi Du 2019Chinese Journal of Chemical Engineering2019,27,4:5
3Persistent hepatitis C virus infections and hepatopathological manifestations in immune-competent humanized mice显示文摘Jizheng Chen Yang Zhao Chao Zhang Hairong Chen Jin Feng Xiumei Chi Yu Pan Jun Du Min Guo Huang Cao Honghe Chen Zilong Wang Rongjuan Pei Qian Wang Lei Pan Junqi Niu Xinwen Chen Hong Tang 2014Cell Research2014,24,9:5
4显示文摘Yang Ming Sun Kunpeng Du Junqi 2002Journal of Beijing University of Chemical Technology2002,29,2:1
5Autumn NDVI contributes more and more to vegetation improvement in the growing season across the Tibetan Platea显示文摘Detecting changes in vegetation,distinguishing the persistence of changes,and seeking their causes during multiple periods are important to gaining a deeper understanding of vegetation dynamics.Using the Global Inventory Modeling and Mapping Studies Normalized Difference Vegetation Index(NDVI)version NDVI_(3g) dataset in the Tibetan Plateau,the trends in the seasonal components of NDVI and their linkage with climatic factors were analyzed over 14 asymptotic periods of 18–31 years since 1982.Dynamic trends in vegetation experienced an obvious increase at regional scale,but the increases of vegetation activity mostly tended to stall or slow down as the studied time period was extended.At pixel scale,areas with significant browning significantly expanded over 14 periods for all seasons,but for significant greening significantly increased only in autumn.The changes of vegetation activity in spring were the most drastic among three seasons.Increased increments of NDVI in summer,spring,and autumn took turns being the main reason for the enhanced vegetation activity in the growing season in the nested 14 periods.Vegetation activity was mainly regulated by a thermal factor,and the dominant climatic drivers of vegetation growth varied across different seasons and regions.We speculate that the increase of NDVI will continue but the increments will decline in all seasons except autumn.Jiaqiang Du Ping He Shifeng Fang Weiling Liu Xinjie Yuan Junqi Yin 2017International Journal of Digital Earth2017,10,11:0
6Phase-sensitive manipulation of squeezed state by a degenerate optical parametric amplifier inside coupled optical resonators显示文摘In this paper, we investigate the quantum fluctuations of subharmonic reflected field from a triple-resonant degenerate optical parametric amplifier(OPA) inside coupled optical resonators, which is driven by the squeezed beam at signal frequency. By controlling the relative phase between the pump beam and the injected signal beam, we can see the quantum fluctuation in the phase direction and amplitude direction due to the parametric down-conversion process in the cavity. Thus, the phase sensitive operation of the compression field is realized due to the quantum interference between the harmonic field of the down converter of OPA and the inner field of the coupled optical resonator. We verified the quantum coherent phenomena of OPA in coupled optical resonators and phase-sensitive manipulations of quantum entanglement for quantum information processing. We realized the electromagnetically induced transparency-like(EIT-like) effect and the optical parameter conversion process at the same time in one optical device. These properties can favor higher manipulation precision and control efficiency, which is more suitable for the integration of quantum-on-chip systems, laying a foundation for the practical application of quantum information.DI Ke WANG Wenbo CUI Wei GUO Junqi LIU Yu DU Jiajia 2022Optoelectronics Letters2022,18,3:0
7Expert consensus on digital guided therapy for endodontic diseases显示文摘Digital guided therapy(DGT)has been advocated as a contemporary computer-aided technique for treating endodontic diseases in recent decades.The concept of DGT for endodontic diseases is categorized into static guided endodontics(SGE),necessitating a meticulously designed template,and dynamic guided endodontics(DGE),which utilizes an optical triangulation tracking system.Based on cone-beam computed tomography(CBCT)images superimposed with or without oral scan(OS)data,a virtual template is crafted through software and subsequently translated into a 3-dimensional(3D)printing for SGE,while the system guides the drilling path with a real-time navigation in DGE.DGT was reported to resolve a series of challenging endodontic cases,including teeth with pulp obliteration,teeth with anatomical abnormalities,teeth requiring retreatment,posterior teeth needing endodontic microsurgery,and tooth autotransplantation.Case reports and basic researches all demonstrate that DGT stand as a precise,time-saving,and minimally invasive approach in contrast to conventional freehand method.This expert consensus mainly introduces the case selection,general workflow,evaluation,and impact factor of DGT,which could provide an alternative working strategy in endodontic treatment.Xi Wei Yu Du Xuedong Zhou Lin Yue Qing Yu Benxiang Hou Zhi Chen Jingping Liang Wenxia Chen Lihong Qiu Xiangya Huang Liuyan Meng Dingming Huang Xiaoyan Wang Yu Tian Zisheng Tang Qi Zhang Leiying Miao Jin Zhao Deqin Yang Jian Yang Junqi Ling 2023International Journal of Oral Science2023,15,4:0
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