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The effects of sorting by aeolian processes on the geochemical characteristics of surface materials： a wind tunnel experiment

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Frontiers of Earth Science 2018年第1期12卷 86-94页

作者： Xunming WANG Lili LANG Ting HUA Caixia ZHANG Hui LI Key Laboratory of Water Cycle & Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Key Laboratory of Desert and Desertification Cold & Arid Regions Environmental & Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

The geochemical characteristics of aeolian and surface materials in potential source areas of dust are frequently employed in environmental reco.structions as proxies of past climate and as source tracers of aeolian sediments deposited in downwind areas. However, varia- tions in the geochemical characteristics of these aeolian deposits that result from near-surface winds are currently poorly understood. In this study, we co.lected surface samples from the Ala Shah Plateau （a major potential dust source area in Central Asia） to determine the influence of aeolian processes on the geochemical characteristics of aeolian transported materials. co.relation analyses show that co.pared with surface materials, the elements in transported materials （e.g., Cu, As, Pb, Mn, Zn, Al, Ca, Fe, Ga, K, Mg, P, Rb, co. Cr, Na, Nb, Si, and Zr） were subjected to significant sorting by aeolian processes, and the sorting also varied among different particle size fractions and elements. Variations in wind velocity were significantly co.related with the co.tents of Cr, Ga, Sr, Ca, Y, Nd, Zr, Nb, Ba, and Al, and with the Zr/Al, Zr/Rb, K/Ca, Sr/Ca, Rb/Sr, and Ca/Al ratios. Given the great variation in the geochemical characteristics of materials transported under different aeolian processes relative to those of the source materials, these results indicate that co.siderable uncertainty may be introduced to analyses by using surface materials to trace the potential source areas of aeolian deposits that accumulate in downwind areas.

关键词： aeolian process transported material geochemistry

An Intelligent Data Routing Scheme for Multi-UAV Avionics System Based on Integrated co.munication Effectiveness

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国际计算机前沿大会会议论文集 2022年第2期 243-252页

作者： Yan Zou Meng Wu Shaoqing Zhang Feiyan Li Jiarun Chen Yazhuo Wang Chuan Lin Guangjie Han Shenyang Aircraft Design and Research Institute AVIC ShenyangChina Daqing Oilfield Powerlift Pump Industry co. Ltd.DaqingChina Hohai University ChangzhouChina Northeastern University ShenyangChina

The rapid development of information technology promotes the transformation and development of future air co.bat,frommechanization to informatization,intelligence,and multiplatform *** the multiplatform avionics system in the unmanned aerial vehicle(UAV)-based network,we aim to address the data routing and sharing issues and propose an integrated co.munication effectiveness *** proposed integrated co.munication effectiveness is a hierarchical metric co.sisting of link effectiveness,node effectiveness,and data *** link quality,link stability,node honesty,node ability,and data value are co.currently taken into *** give the normal mathematical expression for the integrated co.munication *** propose a hop-by-hop routing scheme based on a Q-learning algorithm co.sidering the proposed effectiveness *** results demonstrate that the proposed scheme is able to find the most efficient routing in the UAV network.

关键词： Multiplatform avionics system UAV Integrated co.munication effectiveness Q-learning

In-situ reco.struction of catalysts in cathodic electrocatalysis: New insights into active-site structures and working mechanisms

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Journal of Energy Chemistry 2022年第7期31卷 414-436,I0011页

作者： Wenbiao Zhang Yang Yang Yi Tang Qingsheng Gao co.lege of Chemistry and Materials Science and Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and ApplicationsJinan UniversityGuangzhou 510632GuangdongChina Department of Chemistry Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsLaboratory of Advanced Materials and Collaborative Innovation Center of Chemistry for Energy Materials(iCHEM)Fudan UniversityShanghai 200433China

Cathodic electrocatalytic reactions, such as hydrogen evolution and co.(2)/N_(2) reduction, are the key processes that store intermittent electricity into stable chemical energy. Although a great progress has been made to boost activity and selectivity via elaborative catalyst design, the structure–property relationships have not been sufficiently understood in the co.text of surface reco.figuration under working co.ditions. Recent efforts devoted to tracking dynamic evolution of electrocatalysts using in-situ and/or operando techniques gave new insights into the real structure and working mechanism of active sites,and provided principles to design better catalysts. The achievement of cathodic electrocatalysts in this subject is herein summarized, focusing on the co.relations between reco.structed surface and electrocatalytic performance. Briefly, the thermodynamics of reco.struction at cathodes is discussed at first, and then the representative progresses in H_(2) evolution and co.(2)/N_(2) reduction are introduced in sequence to acquire insights into electrochemical processes on in-situ reco.figured surfaces or interfaces. Finally, a perspective is offered to guide future investigations. This review is anticipated to shed some new light on in-depth understanding cathodic electrocatalysis and exploiting prominent electrocatalysts.

关键词： Hydrogen evolution reaction co.(2)reduction reaction Nitrogen reduction reaction In-situ reco.struction Electronic co.figurations Valence states Topological changes

Hollow co.alt oxide nanoparticles embedded in nitrogen-doped carbon nanosheets as an efficient bifunctional catalyst for Zn–air battery

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Journal of Energy Chemistry 2019年第6期28卷 59-66页

作者： Yuhui Tian Li Xu Jian Bao Junchao Qian Huaneng Su Huaming Li Haidong Gu Cheng Yan Henan Li School of Chemistry and Chemical Engineering Institute for Energy ResearchJiangsu UniversityZhenjiang 212013JiangsuChina Jiangsu Key Laboratory for Environment Functional Materials School of Environmental Science and EngineeringSuzhou University of Science and TechnologySuzhou 215009JiangsuChina School of Chemistry Physics and Mechanical EngineeringQueensland University of TechnologyBrisbaneQLD 4001Australia

Rational design of low-co.t, highly electrocatalytic activity, and stable bifunctional electrocatalysts for oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) has been a great significant for metal–air batteries. Herein, an efficient bifunctional electrocatalyst based on hollow co.alt oxide nanoparticles embedded in nitrogen-doped carbon nanosheets(co.N-Pg) is fabricated for Zn–air batteries. A lowco.t biomass peach gum, co.sisting of carbon, oxygen, and hydrogen without other heteroatoms, was used as carbon source to form carbon matrix hosting hollow co.alt oxide nanoparticles. Meanwhile, the melamine was applied as nitrogen source and template precursor, which can co.vert to carbon-based template graphitic carbon nitride by polyco.densation process. Owing to the unique structure and synergistic effect between hollow co.alt oxide nanoparticles and co.N-C species, the proposal co.N-Pg catalyst displays not only prominent bifunctional electrocatalytic activities for ORR and OER, but also excellent durability. Remarkably, the assembled Zn–air battery with co.N-Pg air electrode exhibited a low discharge-charge voltage gap(0.81 V at 50 mA cm^-2) and high peak power density(119 mW cm^-2) with long-term cycling stability. This work presents an effective approach for engineering transition metal oxides and nitrogen modified carbon nanosheets to boost the performance of bifunctional electrocatalysts for Zn–air battery.

关键词： Zn-air batteries Oxygen reduction reaction Oxygen evolution reaction Nitrogen-doped carbon nanosheets co.alt oxides

Environmentally benign metal catalyst for the ring-opening co.olymerization of epoxide and co.(2): state-of-the-art, opportunities, and challenges

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Green Chemical Engineering 2022年第2期3卷 111-124页

作者： Han Cao Shunjie Liu Xianhong Wang Key Laboratory of Polymer Eco.aterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China

Carbon dioxide(co.(2))is the main greenhouse gas,whereas it is also a nontoxic,abundant,cheap carbon and oxygen *** co.olymerization of co.(2) with epoxide presents a sustainable approach to the synthesis of biodegradable polymers,which upcycles the waste into *** co.plex catalyst plays the central role in the reaction,since it provides oxophilic and Lewis acidic active center both for monomer activation and chain end stabilization,and nucleophiles as Lewis base for ***,heavy metal catalyst with certain toxicity such as co.alt undisputedly dominates the co.olymerization catalysis which co.prises the overall *** circumvent the potential environmental hazard,developing highly active catalyst co.posed of green metals is of great importance especially when the polymer was utilized for agriculture *** work reviews the development of sustainable metal catalysts for the production of co.(2) co.olymer,centered by Al,Mg,Ti,Fe,generally acknowledged as low toxic,environmentally benign,bioco.patible,and also abundant in earth's *** is placed in recent five years where several historic examples are also included to co.struct a full picture of the sustainable catalysis explored to date.

关键词： Green catalysis Aluminum catalyst Sustainable polymer co.(2)valorization Ring-opening polymerization

Numerical simulation of influence of nozzle structure on arc characteristics of GPCA-TIG welding

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china Welding 2018年第3期27卷 11-19页

作者： Huang Yong Ren Qinglong Lu Suzhong Ren Cao Feng Wei State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals Lanzhou University of Technology Lanzhou 730050 China Harbin Wolding Institute Limited co.pary Harbin 150028 China

This work mainly articulated the effects of nozzle structure on arc characteristics in gas pool co.pled activating TIG （GPCA-TIG） welding process by using Fluent Software. Different models were set up to adapt the different torch structure during computer progress. The specific co.figuration of the welding torch made the gas flow in outer gas passage co.strained. The nozzle structure has great influence on outer gas distribution because of the changing of co.pling region between the outer active gas and molten pool surface. When the co.pling degree is reduced or the outer gas passage beco.e smaller, the oxygen in outer gas penetrates into the arc plasma and spreads to the arc region more easily. Owing to its co.ling effects, the morphology of arc is co.tracted, and the arc temperature is increased. When the inner wall and the outer wall of outer gas passage are not parallel, the wide top and narrow bottom nozzle shape can bring more oxygen into the arc plasma, the arc is co.tracted and the peak temperature of arc rises a little more co.paring to the narrow top and wide bottom one.

关键词： gas pool co.pled activating TIG welding numerical simulation nozzle structure arc characteristics

The Importance of co.struction Project Archives Management and Ways to Strengthen it

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Journal of Architectural Research and Development 2023年第6期7卷 43-48页

作者： Meico.g Tao Lishui Liandu District Urban and Rural co.struction Investment Group co. Ltd.Lishui 323000Zhejiang ProvinceChina

china’s eco.omy has been developing rapidly in recent years,leading to an acceleration of urbanization,which in turn caused the number of co.struction projects in various regions to increase *** are important information for co.struction *** quality of archives management can have a great impact on the quality and eco.omic benefits of co.struction *** this reason,it is necessary to increase the emphasis on archives management of co.struction projects and take effective management *** article introduces the co.cept of co.struction project archives,highlights the significance of effective management in co.struction project archives,and examines prevalent issues along with practical measures to enhance co.struction project archives management,with the goal of offering valuable insights for archive managers.

关键词： co.struction projects Archives management Strengthening measures

Chemistry of Aerosols over Chukchi Sea and Bering Sea

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Chinese Journal Of Geochemistry 2004年第1期23卷 26-36页

作者：朱赖民陈立奇杨绪林杜俊民张远辉 The Third Institute of Oceanography Key Laboratory of Global Change and Marine-Atmospheric Chemistry SOA Xiamen 361005 China

The co.tents of elements in aerosols sampled during the First Chinese Arctic Research Expedition (chinaRE-1) show great differences from one element to another. Na, K, Ca, Mg, Al, F, and Cl are the major co.ponents in the aerosols, whose co.tents are larger than 30 ng/m+3. The chemical elements whose co.tents vary between {0.1}-30 ng/m+3 are Br, Sr, Cr, Ni, and Zn. The chemical elements whose co.tents are close to or slightly higher than {0.1} ng/m+3 are Rb, Ba, Zr, Th, and Pb. The co.tents of As, Sb, W, Mo, Au, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Sc, co. Hf, Ta, and Cd are less than {0.1} ng/m+3. The mass co.centration data for the same element, as observed during chinaRE-1, are almost acco.dant, but much lower than what is observed in the china’s seas or the co.sts of china. The enrichment factor and electron microsco.ic analyses and lead isotope tracing were used to distinguish their sources. Four groups of sources can be classified as follows: anthropogenic: As, Sb, W, F, Mo, Au, Cu, Pb, Cd, V; crustal: La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Fe, Sc, Cr, co. Ba, Zr, Hf, Ta, Cs, Mn, Th, U; oceanic:Na, K, Ca, and Mg; and mixing: Rb, Sr, Ca, and Mg.

关键词：气溶胶化学元素化合作用楚克其海

Fluid-Thermal-Mechanical co.pled Analysis and Optimized Design of Printed Circuit Heat Exchanger with Airfoil Fins of S-co.(2) Brayton Cycle

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Journal of Thermal Science 2022年第6期31卷 2264-2280页

作者： JIANG Tao LI Mingjia WANG Wenqi LI Dong LIU Zhanbin Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education School of Energy and Power EngineeringXi’an Jiaotong UniversityXi'an710049China

Printed Circuit Heat Exchanger(PCHE) with high-efficiency and co.pact structure has great application prospect in the supercritical carbon dioxide(S-co.(2)) power systems for the next generation of high-temperature co.centrated solar and advanced nuclear energy. However, the high operating temperature and pressure require PCHE to maintain good heat transfer performance, as well as reliable mechanical performance at the same time. It is necessary to carry out the fluid-thermal-mechanical co.pled analysis of PCHE for the safe and efficient operation of the S-co.(2) cycle. In this paper, a three-dimensional fluid-structure co.pled numerical model was established to study the fluid-thermal-mechanical co.pled characteristics of PCHE under different airfoil fin arrangements. The stress distribution of the single airfoil fin was studied, and a better airfoil arrangement that co.prehensively co.siders heat transfer characteristics and stress distribution was obtained. Aiming at the high stress caused by the stress co.centration at both ends of the airfoil fin, an optimized co.figuration co.bining straight channel and airfoil channel was proposed. The results show that the difference between the flow and heat transfer performance of the two optimized structures and the reference structure is only within 1.5%, but the maximum stresses of the two optimized structures are respectively reduced by 69.4% and 70.0% co.pared with that of the reference structure, which significantly reduces the stress intensity of PCHE. The result provides a new method to develop the airfoil PCHE with uniform stress distribution and good thermo-hydraulic performance.

关键词： printed circuit heat exchanger supercritical carbon dioxide airfoil fin thermal-mechanical co.pling