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Screening performance of methane activation over atomically dispersed metal catalysts on defective boron nitride monolayers:A density functional theory study

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Chinese Chemical Letters 2021年第6期32卷 1972-1976页

作者： Xiao-Ming Cao haijin zhou Liyang Zhao Xuning Chen Peijun Hu Joint International Research Laboratory for Precision Chemistry and Molecular Engineering Centre for Computational Chemistry and Research Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China School of Chemistry and Chemical Engineering The Queen's University of BelfastBelfast BT95AGUnited Kingdom

Methane(CH_(4))controllable activation is the key process for CH_(4)upgrading,which is sensitive to the surface oxygen *** high thermal conductivity and superb thermal stability of the hexagonal boron nitride(h-BN)sheet makes a single transition metal atom doped hexagonal boron nitride monolayer(TM-BN)possible to be a promising material for catalyzing methane partial *** performances of 24 TM-BNs for CH_(4)activation are systematically investigated during the CH_(4)oxidation by means of first-principles *** calculation results unravel the periodic va riation trends for the stability of TM-BN,the adsorption strength and the kind of O_(2)species,and the resulting CH_(4)activation performance on *** formed peroxide O_(2)^(2-)of which the O-O bond could be broken and O-anions are found to be reactive oxygen species for CH_(4)activation under the mild *** is found that the redox potential of TM center,including its valence electron number,coordination environment,and the work function of TM-BN,is the underlying reason for the formation of different oxygen species and the resulting activity for CH_(4)oxidative dehydrogenation.

关键词： Boron nitride monolayer Density functional theory Methane activation Surface reactive oxygen species Transition metal center

A Statistical Algorithm for Retrieving Background Value of Absorbing Aerosol Index Based on TROPOMI Measurements

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Advances in Atmospheric Sciences 2023年第6期40卷 1104-1116页

作者： Fuying TANG Weihe WANG Fuqi SI haijin zhou Yuhan LUO Dongshang YANG Yuanyuan QIAN Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites FengYun Meteorological Satellite Innovation Center(FY-MSIC)China Meteorological Administration(LRCVES/CMA)Beijing 100081China

The ultraviolet aerosol index(UVAI) is essential for monitoring the absorbing aerosols during aerosol events. UVAI depends on the absorbing aerosol concentration, the viewing geometry, and the temporal drift of radiometric sensitivity. To efficiently detect absorbing aerosols with the highest precision and to improve the accuracy of long-term UVAI estimates,the background UVAI must be examined through the UVAI retrieval. This study presents a statistical method that calculates the background value of UVAI using TROPOspheric Monitoring Instrument(TROPOMI) observation data over the Pacific Ocean under clear-sky scenes. Radiative transfer calculations were performed to simulate the dependence of UVAI on aerosol type and viewing geometry. We firstly applied the background UVAI to reducing the effects of viewing geometry and the degradation of the TROPOMI irradiance measurements on the UVAI. The temporal variability of the background UVAI under the same viewing geometry and aerosol concentration was identified. Radiative transfer calculations were performed to study the changes in background UVAI using Aerosol Optical Depth from the Moderate Resolution Imaging Spectroradiometer(MODIS) and reflectance measurements from TROPOMI as input. The trends of the temporal variations in the background UVAI agreed with the simulations. Alterations in the background UVAI expressed the reflectance variations driven by the changes in satellite state. Decreasing trends in solar irradiance at 340 and 380 nm due to instrument degradation were identified. Our findings are valuable because they can be applied to future retrievals of UVAI from the Environmental Trace Gases Monitoring Instrument(EMI) onboard the Chinese GaoFen-5 satellite.

关键词： ultraviolet aerosol index background UVAI TROPOMI reflectance degradation

Atmospheric environment monitoring technology and equipment in China:A review and outlook

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Journal of Environmental Sciences 2023年第1期123卷 41-53页

作者： Youwen Sun Ting Yang Huaqiao Gui Xin Li Weigang Wang Jun Duan Shushuai Mao Hao Yin Bin zhou Jianlei Lang haijin zhou Cheng Liu Pinhua Xie Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsHFIPSChinese Academy of SciencesHefei 230031China Department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of ChemistryChinese Academy of SciencesBeijing 100190China Key Laboratory of Beijing on Regional Air Pollution Control College of Environmental&Energy EngineeringBeijing University of TechnologyBeijing 100124China Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention(LAP3) Department of Environmental Science and EngineeringFudan UniversityShanghai 200438China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes University of Science and Technology of ChinaHefei 230026China Anhui Province Key Laboratory of Polar Environment and Global Change University of Science and Technology of ChinaHefei 230026China

Accurate monitoring of the atmospheric environment and its evolution are important for understanding the sources,chemical mechanisms,and transport processes of air pollution and carbon emissions in China,and for regulatory and control *** study gives an overview of atmospheric environment monitoring technology and equipment in China and summarizes the major achievements obtained in recent *** has made great progress in the development of atmospheric environment monitoring technology and equipment with decades of *** manufacturing level of atmospheric environment monitoring equipment and the quality of products have steadily improved,and a technical&production system that can meet the requirements of routine monitoring activities has been *** is expected that domestic atmospheric environment monitoring technology and equipment will be able to meet future demands for routine monitoring activities in China and provide scientific assistance for addressing air pollution problems.

关键词： Atmospheric pollution Atmospheric environment Atmospheric monitoring Environmental instrument

First observation of tropospheric nitrogen dioxide from the Environmental Trace Gases Monitoring Instrument onboard the GaoFen-5 satellite

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Light(Science & Applications) 2020年第1期9卷 1389-1397页

作者： Chengxin Zhang Cheng Liu Ka Lok Chan Qihou Hu Haoran Liu Bo Li Chengzhi Xing Wei Tan haijin zhou Fuqi Si Jianguo Liu School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsChinese Academy of SciencesHefei 230031China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes University of Science and Technology of ChinaHefei 230026China Remote Sensing Technology Institute(IMF) German Aerospace Center(DLR)OberpfaffenhofenGermany

The Environmental Trace Gases Monitoring Instrument(EMI)is the first Chinese satellite-borne UV–Vis spectrometer aiming to measure the distribution of atmospheric trace gases on a global *** EMI instrument onboard the GaoFen-5 satellite was launched on 9 May *** this paper,we present the tropospheric nitrogen dioxide(NO2)vertical column density(VCD)retrieval algorithm dedicated to EMI *** report the first successful retrieval of tropospheric NO_(2) VCD from the EMI *** retrieval improved the original EMI NO_(2) prototype algorithm by modifying the settings of the spectral fit and air mass factor calculations to account for the on-orbit instrumental performance *** retrieved EMI NO_(2) VCDs generally show good spatiotemporal agreement with the satellite-borne Ozone Monitoring Instrument and TROPOspheric Monitoring Instrument(correlation coefficient R of ~0.9,bias<50%).A comparison with ground-based MAX-DOAS(Multi-Axis Differential Optical Absorption Spectroscopy)observations also shows good correlation with an R of *** results indicate that the EMI NO_(2) retrieval algorithm derives reliable and precise results,and this algorithm can feasibly produce stable operational products that can contribute to global air pollution monitoring.

关键词： measurement dioxide satellite

Structure and ion transport properties of organic ionic compounds revealed by NMR

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Magnetic Resonance Letters 2024年第2期4卷 2-12页

作者： haijin Zhu Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion Guangdong Technion-Israel Institute of TechnologyShantou515063China

Organic ionic plastic crystals(OIPCs)are emerging as an important material family for solid-state electrolytes and many other *** have significant advantages over conventional electrolyte materials,such as high ionic conductivity,non-flammability,and *** nuclear magnetic resonance(NMR)spectroscopy techniques including solid-state NMR,pulsed-field gradient(PFG)NMR,and magnetic resonance imaging(MRI)etc.,provide us a versatile toolkit to understand the fundamental level structures,molecular dynamics,and ionic interactions in these *** article reviews the commonly used NMR methods including solid-and solution-state NMR,PFG-NMR,dynamic nuclear polarization(DNP)and the application of these methods in revealing the microscopic level structures and ion-transport mechanisms in OIPC materials.

关键词： NMR Electrolyte Organic ionic plastic crystals Defects Diffusion Microstructure

Preliminary measurements of boundary layer reactive halogens based on MAXDOAS technique over Salt Lake in West China

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Acta Geologica Sinica(English Edition) 2014年第S1期88卷 229-230页

作者： LUO Yuhan SI Fuqi DOU Ke zhou haijin XIE Pinhua Anhui Institute of Optics and Fine Mechanism Chinese Academy of Sciences

The reactive halogens play key roles in the destruction of boundary layer ozone by catalytic reactions and provide a fast pathway to the sedimentation of elemental gaseous *** presence of bromine oxides in the lower

关键词： reactive halogens MAX-DOAS salt lake

ANALYSIS OF THE IMPLICIT-EXPLICIT ULTRA-WEAK DISCONTINUOUS GALERKIN METHOD FOR CONVECTION-DIFFUSION PROBLEMS

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Journal of Computational Mathematics 2024年第1期42卷 1-23页

作者： haijin Wang Anping Xu Qi Tao School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China Beijing Computational Science Research Center Beijing 100193China

In this paper,we first present the optimal error estimates of the semi-discrete ultra-weak discontinuous Galerkin method for solving one-dimensional linear convection-diffusion ***,coupling with a kind of Runge-Kutta type implicit-explicit time discretization which treats the convection term explicitly and the diffusion term implicitly,we analyze the stability and error estimates of the corresponding fully discrete *** fully discrete schemes are proved to be stable if the time-stepτ≤τ0,whereτ0 is a constant independent of the mesh-size ***,by the aid of a special projection and a careful estimate for the convection term,the optimal error estimate is also obtained for the third order fully discrete *** experiments are displayed to verify the theoretical results.

关键词： The ultra-weak discontinuous Galerkin method Convection-diffusion Implicitexplicit time discretization Stability Error estimate

人白细胞介素-26慢病毒表达质粒与基因敲除质粒的构建及其在HEK293T细胞中的活性验证

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中国生物制品学杂志 2024年第2期37卷 151-159页

作者：周海金吴珊刘丽媛蒋丹许涛蓝华滔舒纬童徐广贤广东医科大学医学技术学院医学检验系广东东莞523000 宁夏医科大学临床医学院宁夏银川750004

目的构建人白细胞介素(interleukin,IL)-26慢病毒表达质粒与基因敲除质粒,为研究IL-26基因在细胞信号通路及细胞自噬中的功能奠定基础。方法利用RT-PCR从人外周血单个核细胞中扩增IL-26基因序列,克隆至pCDH-CMV-MCS-EF1-copGFP真核表... 详细信息

目的构建人白细胞介素(interleukin,IL)-26慢病毒表达质粒与基因敲除质粒,为研究IL-26基因在细胞信号通路及细胞自噬中的功能奠定基础。方法利用RT-PCR从人外周血单个核细胞中扩增IL-26基因序列,克隆至pCDH-CMV-MCS-EF1-copGFP真核表达载体中,构建过表达质粒;并根据IL-26外显子序列设计4个敲除靶点Exon1sgRNA1、Exon1sgRNA2、Exon3sgRNA1、Exon3sgRNA2,利用CRISPR/Cas9技术构建至lentiCRISPRv2载体中,构建基因敲除质粒。将过表达质粒和基因敲除质粒分别瞬时转染至HEK293T细胞,利用RT-qPCR和Western blot验证IL-26 mRNA和蛋白的表达情况。并对IL-26进行氨基酸序列分析、结构预测及亚细胞定位观察。结果通过酶切、测序鉴定及生物信息学分析显示,IL-26全长516 bp,编码171个氨基酸。IL-26过表达质粒转染的HEK293T细胞与正常对照组相比,IL-26 mRNA水平升高了656.789倍,蛋白质水平升高了1.978倍,差异均有统计学意义(t分别为17.976和7.859,P分别<0.000 1和<0.001)。4个敲除靶点Exon1sgRNA1、Exon1sgRNA2、Exon3sgRNA1、Exon3sgRNA2质粒转染至HEK293T细胞中后,IL-26的表达水平分别下降了0.930、0.980、0.523 3和0.316 9倍,其中Exon3-sgRNA2质粒能够显著下调IL-26的表达(t=7.440,P <0.001)。IL-26蛋白的前22个氨基酸存在信号肽结构,且具有一定的跨膜功能,IL-26存在于细胞质中。结论成功构建了IL-26过表达和基因敲除质粒,为后续IL-26功能的研究奠定了基础。

关键词：白细胞介素-26 过表达质粒基因敲除质粒生物信息学

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非洲华侨华人生存状况及其与当地族群关系

东南亚研究 2014年第1期 79-84页

作者：周海金浙江师范大学非洲研究院浙江金华321004

当代中非关系的全面提升带来了双边民间交往的快速发展,越来越多的中国人去非洲工作、留学和生活。目前非洲华侨华人已达百万人之多,主要分为三种类型:劳工移民、创业移民和过境移民。他们在农业开发、基础设施建设和加工零售等各行业... 详细信息

当代中非关系的全面提升带来了双边民间交往的快速发展,越来越多的中国人去非洲工作、留学和生活。目前非洲华侨华人已达百万人之多,主要分为三种类型:劳工移民、创业移民和过境移民。他们在农业开发、基础设施建设和加工零售等各行业日益活跃,为非洲的经济社会发展作出了重要贡献,从而得到大部分非洲民众的普遍认可与欢迎。但与此同时,华侨华人自身封闭的生活习惯,西方媒体的煽风点火,以及所在国的政治和党派斗争都阻碍了华侨华人积极有效地融入当地社会,从而为自己埋下了安全隐患。因此,非洲华侨华人也面临着自己的生存困境,以及如何妥善处理与当地族群关系的问题。

关键词：非洲华侨华人生存状况族群关系