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Observation of Wind Shear during Evening Transition and an Estimation of Submicron Aerosol Concentrations in Beijing Using a Doppler Wind Lidar

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Journal of Meteorological Research 2017年第2期31卷 350-362页

作者： yong CHEN Junling AN Xiquan WANG Yele SUN Zifa WANG Jing duan State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029 Center for Excellence in Urban Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021 Chinese Academy of Meteorological Sciences Beijing 100081

The wind speed and direction measured over six months by a Doppler wind lidar（Windcube-8）were compared with wind cup anemometers mounted on the 325-m Beijing meteorological tower（BMT）.Five mountain–plain wind cases characterized by wind direction shear were selected based on the high-frequency（1.1 s）wind profile of the Windcube-8 and analyzed with 1-h mesoscale surface weather *** analyzed was the relationship between insitu PM_1（aerodynamic diameter≤1μm）concentrations measured at 260 m on BMT and the carrier-to-noise ratio（CNR）of the co-located *** results showed that the 10-min averaged wind speed and direction were highly correlated（R=0.96–0.99）at three matched levels（80,140,and 200 m）.The evening transition duration was1–3 h,with an average wind speed of 1 m s^（–1） at 80 m above the *** addition,there was a zero horizontalwind-speed zone along the wind direction shear line,and in one case,the wind speed was characterized by a Kelvin–Helmholtz gravity *** variability of the PM_1 concentrations was captured by the CNR of the Windcube-8 in a fair weather period without the long-range transport of dust.

关键词： mountain–plain wind wind shear wind lidar PM_1

Two-dimensional nanomaterials confined single atoms: New opportunities for environmental remediation

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Nano Materials Science 2023年第1期5卷 15-38页

作者： Yu Yin Lei Shi shu Zhang Xiaoguang duan Jinqiang Zhang Hongqi Sun Shaobin Wang School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang212100China Joint International Research Laboratory of Biomass Energy and Materials College of Materials Science and EngineeringNanjing Forestry UniversityNanjing210037China School of Chemical Engineering and Advanced Materials The University of AdelaideAdelaideSA5005Australia School of Science Edith Cowan UniversityJoondalupWA6027Australia

Two-dimensional(2D)supports confined single-atom catalysts(2D SACs)with unique geometric and electronic structures have been attractive candidates in different catalytic applications,such as energy conversion and storage,value-added chemical synthesis and environmental ***,their environmental appli-cations lack of a comprehensive summary and in-depth *** this review,recent progresses in synthesis routes and advanced characterization techniques for 2D SACs are introduced,and a comprehensive discussion on their applications in environmental remediation is ***,2D SACs can be effective in catalytic elimination of aqueous and gaseous pollutants via radical or non-radical routes and transformation of toxic pollutants into less poisonous species or highly value-added products,opening a new horizon for the contami-nant *** addition,in-depth reaction mechanisms and potential pathways are systematically discussed,and the relationship between the structure-performance is ***,several critical challenges within this field are presented,and possible directions for further explorations of 2D SACs in environmental remediation are *** the research of 2D SACs in the environmental application is still in its infancy,this review will provide a timely summary on the emerging field,and would stimulate tremendous interest for designing more attractive 2D SACs and promoting their wide applications.

关键词： Single-atom catalysis Two-dimensional material Advanced oxidation process Degradation Transformation Industrial wastewater

Multi-beam and seismic investigations of the active Haima cold seeps,northwestern South China Sea

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Acta Oceanologica Sinica 2021年第7期40卷 183-197页

作者： Bin Liu Jiangxin Chen Li Yang Minliang duan Shengxuan Liu yongxian Guan Pengcheng shu Key Laboratory of Marine Mineral Resources Guangzhou Marine Geological SurveyMinistry of Natural ResourcesGuangzhou 510760China Key Laboratory of Gas Hydrate Qingdao Institute of Marine GeologyMinistry of Natural ResourcesQingdao 266071China Laboratory for Marine Mineral Resources Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266071China Key Laboratory of Submarine Geosciences and Prospecting Techniques of Ministry of Education Ocean University of ChinaQingdao 266100China

To confirm the seabed fluid flow at the Haima cold seeps,an integrated study of multi-beam and seismic data reveals the morphology and fate of four bubble plumes and investigates the detailed subsurface structure of the active seepage *** shapes of bubble plumes are not constant and influenced by the northeastward bottom currents,but the water depth where these bubble plumes disappear(630–650 m below the sea level)(mbsl)is very close to the upper limit of the gas hydrate stability zone in the water column(620 m below the sea level),as calculated from the CTD data within the study area,supporting the“hydrate skin”*** chimneys directly below the bottom simulating reflectors,found at most sites,are speculated as essential pathways for both thermogenic gas and biogenic gas migrating from deep formations to the gas hydrate stability *** fracture network on the top of the basement uplift may be heavily gas-charged,which accounts for the chimney with several kilometers in diameter(beneath Plumes B and C).The much smaller gas chimney(beneath Plume D)may stem from gas saturated localized strong permeability ***-resolution seismic profiles reveal pipe-like structures,characterized by stacked localized amplitude anomalies,just beneath all the plumes,which act as the fluid conduits conveying gas from the gas hydrate-bearing sediments to the seafloor,feeding the gas *** differences between these pipe-like structures indicate the dynamic process of gas seepage,which may be controlled by the build-up and dissipation of pore *** 3D seismic data show high saturated gas hydrates with high RMS amplitude tend to cluster on the periphery of the gas *** the fluid migration and hydrate accumulation pattern of the Haima cold seeps can aid in the further exploration and study on the dynamic gas hydrate system in the South China Sea.

关键词： fluid escape cold seep natural gas hydrate bubble plume Qiongdongnan Basin South China Sea

Electrocatalytic C0_(2) Reduction with Re-Based Spiro Bipyridine Complexes: Effects of the Local Proton in the Second Coordination Sphere

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Chinese Journal of Chemistry 2021年第5期39卷 1281-1287页

作者： yong Yang Ziyun Zhang Zhenyu Zhang Chao Tang Xiaoyong Chang Lele duan Department of Chemistry Shenzhen Grubbs Institute and Guangdong Provincial Key Laboratory of Energy Materials for Electric PowerSouthern University of Science and TechnologyShenzhenGuangdong 518055China

We report herein a Re-based tricarbonyl catalyst[fac-Re(L1)(CO)_(3)Cl](Re1)bearing a spiro center and a phenol group as a local proton source in the second coordination *** to the large steric spiro group,dimerization of one-electron reduced species was completely eliminated,improving the stability of ***,the phenol group in the second coordination sphere improves the formation of an H-bonding chain that promotes the protonation of C0_(2) reduction intermediates,boosting the electrocatalytic C0_(2) reduction activity of *** studies reveal that the doubly reduced complex Re1b is active for C0_(2) addition.

关键词： Rhenium Homogeneous catalysis Second coordination sphere Electrochemistry CO_(2)reduction

Growth model of cavity generated by the projectile impacting liquid-filled tank

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Defence Technology（防务技术） 2020年第3期16卷 609-616页

作者： Bei-lei Zhao Ji-guang Zhao Cun-yan Cui yong-sheng duan Yan Wang Department of Aerospace Science and Technology Space Engineering UniversityBeijing 101416China Department of Electronic and Optical Engineering Space Engineering UniversityBeijing 101416China

The high-speed impact of a projectile on a liquid-filled tank causes the hydraulic ram,in which a cavity is *** study the growth characteristics of the cavity,the formation mechanism of the cavity is *** effect of Reynolds number and Mach number on drag coefficient is considered,the axial and radial growth models of the cavity are established *** relative errors between the cavity length calculated by the axial growth model,the cavity diameter calculated by the radial growth model and Ma *** results are less than 20%,which verifies the effectiveness of the axial and radial growth ***,numerical simulation is carried out to study the growth characteristics of the cavity caused by the projectile impacting the satellite tank at the velocity of 4000 m/*** cavity length and diameter calculated by the axial and radial growth models agree well with those obtained by simulation results,indicating that the cavity length and diameter in satellite tank can be accurately calculated by the axial and radial growth models.

关键词： Projectile Impact Liquid-filled tank Cavity Axial growth model Radial growth model

Preparation of transparent BaSO_(4) nanodispersions by high-gravity reactive precipitation combined with surface modification for transparent X-ray shielding nanocomposite films

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Frontiers of Chemical Science and Engineering 2021年第4期15卷 902-912页

作者： Le Fang Qian Sun yong-Hong duan Jing Zhai Dan Wang Jie-Xin Wang Beijing Advanced Innovation Center for Soft Matter Science and Engineering State Key Laboratory of Organic-Inorganic CompositesBeijing University of Chemical TechnologyBeijing 100029China Research Center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing 100029China Mine Oil Products Branch Coal Science and Technology Research Institute CompanyBeijing 100013China

BaSO_(4) nanoparticles as important functional materials have attracted considerable research interests,due to their X-rays barrier and absorption ***,most of BaSO_(4) nanoparticles prepared by traditional technology are nanopowders with broad size distribution and poor dispersibility,which may greatly limit their *** the best of our knowledge,the synthesis of transparent BaSO_(4) nanodispersions was rarely ***,we firstly present a novel and efficient method to prepare transparent and stable BaSO_(4) nanodispersions with a relatively small particle size around 10 to 17 nm using a precipitation method in a rotating packed bed(RPB),followed by a modification treatment using stearic *** with the BaSO_(4) prepared in a traditional stirred tank,the product prepared using an RPB has much smaller particle size and narrower size *** importantly,by using RPB,the reaction time can be significantly decreased from 20 min to 18 ***,the transparent BaSO_(4)-polyvinyl butyral nanocomposite films with good X-ray shielding performance can be easily *** believe that the stable BaSO_(4) nanodispersions may have a wide range of applications for transparent composite materials and coatings with X-ray shielding performance for future research.

关键词： BaSO_(4)nanoparticles rotating packed bed transparent nanodispersions BaSO_(4)-PVB films X-ray

Optimization of submerged entry nozzle parameters for ultra-high casting speed continuous casting mold of billet

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Journal of Iron and Steel Research International 2022年第1期29卷 44-52页

作者： Pei Xu yong-zhi Zhou Deng-fu Chen Mu-jun Long Hua-mei duan Laboratory of Metallurgy and Materials College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China

Controlling the flow behavior in the mold in an appropriate way is the basis for realizing the billet ultra-high speed continuous *** on the new proposed physical water modeling experiment considering the effects of solidified shell and hydrostatic pressure,the flow behavior in the mold with cross section of 160 mm 9160 mm during continuous casting of billet is regulated by optimizing the inner diameters and immersion depths of submerged entry nozzle at the ultra-high casting speeds of 5.0–6.5 m/*** results show that under the premise of no slag entrainment,as well as uniform coverage and keeping good fluidity of liquid slag layer on the top free surface of the fluid in the mold,the appropriate parameters of submerged entry nozzle under the ultra-high casting speed of billet are 50 mm in inner diameter,95 mm in outer diameter and 180 mm in immersion *** on the basis of the obtained parameters of submerged entry nozzle,it can be known that the reasonable ranges of level fluctuation and impacting depth of the stream in the mold are about 0.82-1.11 and 593-617 mm,respectively.

关键词： Ultra-high casting speed Billet continuous casting Submerged entry nozzle Physical water modeling Flow behavior

The effect of the density difference between supercritical CO_(2) and supercritical CH_(4) on their adsorption capacities: An experimental study on anthracite in the Qinshui Basin

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Petroleum Science 2022年第4期19卷 1516-1526页

作者： Si-Jie Han shu-Xun Sang Piao-Piao duan Jin-Chao Zhang Wen-Xin Xiang Ang Xu Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization China University of Mining and TechnologyXuzhouJiangsu221008China Carbon Neutrality Institute China University of Mining and Technology XuzhouJiangsu221008China School of Resources and Geosciences China University of Mining and TechnologyXuzhouJiangsu221116China

Deep unmineable coals are considered as economic and effective geological media for CO_(2) storage and CO_(2) enhanced coalbed methane(CO_(2)-ECBM) recovery is the key technology to realize CO_(2) geological sequestration in coals. Anthracite samples were collected from the Qinshui Basin and subjected to mercury intrusion porosimetry, low-pressure CO_(2) adsorption, and high-pressure CH_(4)/CO_(2) isothermal adsorption experiments. The average number of layers of adsorbed molecules(ANLAM) and the CH_(4)/CO_(2) absolute adsorption amounts and their ratio at experimental temperatures and pressures were calculated. Based on a comparison of the density of supercritical CO_(2) and supercritical CH_(4), it is proposed that the higher adsorption capacity of supercritical CO_(2) over supercritical CH_(4) is the result of their density differences at the same temperature. Lastly, the optimal depth for CO_(2)-ECBM in the Qinshui Basin is recommended. The results show that:(1) the adsorption capacity and the ANLAM of CO_(2) are about twice that of CH_(4) on SH-3 anthracite. The effect of pressure on the CO_(2)/CH_(4) absolute adsorption ratio decreases with the increase of pressure and tends to be consistent.(2) A parameter(the density ratio between gas free and adsorbed phase(DRFA)) is proposed to assess the absolute adsorption amount according to the supercritical CO_(2)/CH_(4) attributes. The DRFA of CO_(2) and CH_(4) both show a highly positive correlation with their absolute adsorption amounts, and therefore, the higher DRFA of CO_(2) is the significant cause of its higher adsorption capacity over CH_(4) under the same temperature and pressure.(3) CO_(2) adsorption on coal shows micropore filling with multilayer adsorption in the macro-mesopore, while methane exhibits monolayer surface coverage.(4) Based on the ideal CO_(2)/CH_(4) competitive adsorption ratio, CO_(2) storage capacity, and permeability variation with depth, it is recommended that the optimal depth for CO_(

关键词： CO_(2)geological storage Competitive adsorption Deep unmineable coal Average number of layers of adsorbed molecules Density ratio between free phase and adsorbed phase Micropore filling

Ising Superconductivity and Its Hidden Variants

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Accounts of Materials Research 2021年第7期2卷 526-533页

作者： Chong Wang yong Xu Wenhui duan Department of Physics Carnegie Mellon UniversityPittsburghPennsylvania 15213United States State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084China RIKEN Center for Emergent Matter Science(CEMS) WakoSaitama 351-0198Japan Frontier Science Center for Quantum Information Beijing 100084China State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics and Institute for Advanced Study Tsinghua UniversityBeijing 100084China

CONSPECTUS:The magnetic field usually suppresses super***,at the critical magnetic field,superconductivity is *** superconductivity is a mechanism where the spin−orbit coupling significantly increases the in-plane critical magnetic field in some two-dimensional *** Account reviews the recent theoretical and experimental research progresses in Ising superconductivity and its *** conventional two-dimensional superconductors,the critical inplane magnetic field is known as the Pauli *** the critical field,the spin Zeeman energy is comparable to the superconductivity gap and therefore destroys *** contrast,in Ising superconductors,the bands are spin-split and the spins are polarized in the out-of-plane *** spin-polarized bands compete with external magnetic field such that superconductivity can survive in a magnetic field which is larger than the Pauli ***,Ising superconductivity is first identified in few layer MoS2 and the critical field in some cases is found to be 5 times larger than the Pauli *** superconductivity originally requires inversion asymmetric systems where bands are ***,variants of Ising superconductivity can be realized in inversion symmetric materials where the spin−orbit coupling effects are manifested in a more elusive *** this Account,Ising superconductivity hidden in the real space and Ising superconductivity hidden in the orbital space are *** superconductivity hidden in the real space relies on the fact that some inversion symmetric materials can be divided into two sectors in the real *** two sectors are both inversion asymmetric and are weakly interacting with each *** the bands in these materials are spin degenerate,the spin up and spin down partner of every band reside in different *** the spin Zeeman interaction is diagonal in sector space,the induced Zeeman splitting

关键词： bands superconductivity Ising