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Full lifetime demonstration of a micro-Cathode-Arc thruster evolution characteristics

Chinese Journal of Aeronautics 2024年第6期37卷 38-49页

作者： zhe zhang Zijing ZHAO Xiangyang LIU Ningfei WAng School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

Ground lifetime test is the most crucial experiment to assess the performance,*** flight qualification of electric propulsion,and it can bring new insights for understanding the operation *** work demonstrates a full lifetime test of 140000 cycles on a micro-Cathode-Arc Thruster(μCAT)with 160μs charging time and 86 mJ charging energy.A four-probe resistivity measurement method is utilized to investigate variations in the conductive film thickness and resistivity throughout the thruster *** film parameters show that the lifetime of theμCAT can be divided into three *** the initial stage,the film thickness decreases by 1.2μm and the resistivity increases significantly due to the high discharge intensity and intense film ablation;In the steady stage,the change of the film thickness is within 5%,and the resistivity of the film increases slowly from 0.050Ω·mm to 0.223Ω·*** the end stage,the resistivity exponentially increases from 0.223Ω·mm to 1.176Ω·mm,with the increase accounting for 81%,ultimately resulting in the failure of the thruster open ***,the evolution of discharge parameters,and the variation of plume parameters are measured throughout the *** discharge characteristics also show significant differences in the duration of voltage and current in these three *** results of plume shape and plasma parameters are also well con-sistent with the discharge parameters and film *** results suggest that,for evaluating the steady stage lifetime of thrusters,the film thickness is the best indicator compared to the variations in resistivity and voltage-current *** the end stage,the plasma plume *** duration,and plume parameters can conveniently and clearly characterize the thruster failures and irregularity.

关键词： Electric propulsion Lifetime test micro-Cathode-Arc Thruster(uCAT) Conductive film Discharge characteristics Plasma parameters

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The mW5.5 earthquake on August 6,2023,in Pingyuan,Shandong,China:A rupture on a buried fault

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Earthquake Science 2024年第1期37卷 1-12页

作者： zhe zhang Lisheng Xu Lihua Fang Institute of Geophysics China Earthquake AdministrationBeijing 100081China

On August 6,2023,a magnitude mW5.5 earthquake struck Pingyuan County,Dezhou City,Shandong Province,*** event was significant as no large earthquakes had been recorded in the region for over a century,and no active fault had been previously *** study collects 1309 P-wave arrival times and 866 S-wave arrival times from 74 seismic stations less than 200 km to the epicenter to constrain the spatial distribution of the mainshock and its 125 early aftershocks by the double difference earthquake relocation method,and selects 864 P-waveforms from 288 stations located within 800 km of the epicenter to constrain the focal mechanism solution of the mainshock through centroid moment tensor *** relocation and the inversion indicate,the Pingyuan mW5.5 earthquake was caused by a rupture on a buried fault,likely an extensive segment of the Gaotang *** buried fault exhibited a dip of approximately 75°to the northwest,with a strike of 222°,similar to the Gaotang *** rupture initiated at the depth of 18.6 km and propagated upward and ***,the ground surface was not *** total duration of the rupture was~6.0 s,releasing the scalar moment of 2.5895×1017 N·m,equivalent to *** moment rate reached the maximum only 1.4 seconds after the rupture initiation,and the 90%scalar moment was released in the first 4.6 *** the first 1.4 seconds of the rupture process,the rupture velocity was estimated to be 2.6 km/s,slower than the local S-wave *** the rupture neared its end,the rupture velocity decreased *** study provides valuable insights into the seismic characteristics of the Pingyuan mW5.5 earthquake,shedding light on the previously unidentified buried fault responsible for the seismic activity in the *** the behavior of such faults is crucial for assessing seismic hazards and enhancing earthquake preparedness in the future.

关键词： Shandong Pingyuan mW5.5 earthquake double-difference earthquake location centroid moment tensor inversion buried fault

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Abundance and sources of particulate polycyclic aromatic hydrocarbons and aromatic acids at an urban site in central China

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Journal of Environmental Sciences 2024年第8期142卷 155-168页

作者： Luqi Shang zhe Dong Zihan Li m.ngkai Wang Zihan Kong Xiao Li Ruiqin zhang School of Ecology and Environment Zhengzhou UniversityZhengzhou 450001China College of Chemistry Zhengzhou UniversityZhengzhou 450001China Institute of Environmental Sciences Zhengzhou UniversityZhengzhou 450001China

We conducted a simultaneous field study of Pm_(2.5)-bound particulate polycyclic aromatic hydrocarbons(PAHs)and aromatic acids(AAs)in a polluted city zhengzhou to explore the concentration,sources and potential conversion pathways between PAHs and AAs in different *** average concentrations of Pm_(2.5),28PAHs and 8AAs during the sampling period were 77μg/m^(3),75 ng/m^(3),and 283 ng/m^(3),*** concentration of both28PAHs and 8AAs were highest in winter and lowest in summer with ratios of 6.3 and 2.3,*** with 5-7 rings were the main components of PAHs(52%),followed by 4rings PAHs(30%)and 2-3 rings PAHs(18%).According to the source appointment results obtained by positive matrix factorization,the main sources of PAHs were combustion and vehicle emissions,which account for 37%and 34%,respectively.8AAs were divided into three groups,including four benzene dicarboxylic acids(B2CAs),three benzene tricarboxylic acids(B3CAs)and one benzene tetracarboxylic acid(B4CA).And interspecies correlation analysis with Pm_(2.5)source markers were used to investigate potential *** acid(o-Ph)was the most abundant specie of 8AAs(157 ng/m^(3),55%of 8AAs),which was well correlated with ***,B3CAs and B4CA were highly correlated with sulfate and weakly correlated with levoglucosan,suggesting that secondary formation was their main *** logical oxidation products of PAHs,o-Ph and B3CAs showed good correlations with a number of PAHs,indicating possible photochemical oxidation pathway by *** addition,O_(3),NO_(2),temperature and relative humidity have positive effects on the secondary formation of B3CAs.

关键词： Polycyclic aromatic hydrocarbons Aromatic acids Source appointment Secondary formation

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High Colloidal Stable Carbon Dots Armored Liquid metal Nano-Droplets for Versatile 3D/4D Printing Through Digital Light Processing(DLP)

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Energy & Environmental materials 2024年第3期7卷 432-438页

作者： Linan Wang Junle zhang Xi zhang Ge Shi Yanjie He zhe Cui Xiaom.ng zhang Peng Fu minying Liu Xiaoguang Qiao Xinchang Pang Henan Joint International Research Laboratory of Living Polymerizations and Functional Nanomaterials Henan Key Laboratory of Advanced Nylon Materials and ApplicationSchool of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China College of materials Engineering Henan International Joint Laboratory of Rare Earth Composite MaterialsHenan Engineering Technology Research Center for Fiber Preparation and ModificationHenan University of EngineeringZhengzhou 451191China

Liquid metal(Lm)and liquid metal alloys(Lms)possess unique physicochemical features,which have become emerging and functionalized materials that are attractive applicants in various ***,uniform Lm nanodroplets armored by carbon dots(LmD@CDs)were prepared and exhibited high colloidal stability in various solvents,as well as *** optimization,LmD@CDs can be applied as functional additives for the 3D/4D printing of hydrogel and cross-linked resin through digital light processing(DLP).The light absorption of LmD@CDs not only improved the printing accuracy,but also led to the cross-linking density differential during the post-curing *** on the cross-linking density differential of soft hydrogel and photothermal performance of the Lm,the 3D printed objects can exhibit stimulus responses to both water and laser ***,the CDs shell and Lm core of LmD@CDs provide the printed objects interesting photoluminescence and electric conductivity capabilities,*** deduce this versatile 3D/4D printing system would provide a new platform for the preparation of multi-functional and stimuli-responsive advance materials.

关键词： 4D printing carbon dots liquid metal nanodroplets

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D-band center coordination modulated enzyme-like activity in Fe-Cu dual-metal single-atom nanozymes

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Nano Research 2024年第7期17卷 5872-5883页

作者： Ling Liu Shaofang zhang Guo Li Yadong zhe Jiamin Liu Xinxu zhang Jiahao Wei Xin Sun Yonghui Li Xiao-Dong zhang Tianjin Key Laboratory of Brain Science and Neural Engineering Academy of Medical Engineering and Translational MedicineTianjin UniversityTianjin 300072China Department of Physics and Tianjin Key Laboratory of Low Dimensional materials Physics and Preparing Technology School of SciencesTianjin UniversityTianjin 300350China

After explorations in a diversity of single-atom nanozymes(SAzymes),developing dual-centered SAzymes becomes a promising approach for superior catalytic *** confusing mechanisms including atomic coordination,spatial configuration,and metal–metal atom interaction hinder the development and design of ***,a dual-centered Fe-Cu-N_(x)SAzyme exhibits excellent peroxidase(POD)-and catalase(CAT)-like activities with d-band center(ε_(d))coordination of Fe and Cu in multiple reaction stages,which plays a critical role in the adsorption of H_(2)O_(2)molecule and H_(2)O and O_(2)***,the dband center coordination,which can be represented byε_(d)(Fe)–ε_(d)(Cu)shifts,leads to the competition between one-side and bilateral adsorption,which determines the favorable reaction path with lower energy *** on experimental statistics,simulated formation energies,and reaction barriers,3 configurations,Fe-Cu-N6-I,Fe-Cu-N_(8)-II,and Fe-Cu-N_(8)-III,are modeled and ***,configuration-dependent catalytic selectivity and the competition between one-side and bilateral adsorption can be unveiled by d-band center coordination paradigm *** simulations suggest that the unsymmetrical charge distribution over the three Fe-Cu configurations could tune the adsorption strength compared with the counterparts FeN_(4)and CuN_(4).The present work provides a potential route for optimizing enzyme-like catalysis by designing the dual-or even triple-metal SAzymes,which demonstrates the large space to modulate the metal atomic configuration and interaction.

关键词： single-atom catalysis Fe-Cu dual-metal d-band center coordination enzyme mimicking competitive adsorption mechanisms

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Reversible mn^(2+)/mn^(4+)double-electron redox in P3-type layer-structured sodium-ion cathode

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Journal of Energy Chemistry 2024年第2期89卷 79-88,I0004页

作者： Jie Zeng Jian Bao Ya zhang Xun-Lu Li Cui ma Rui-Jie Luo Chong-Yu Du Xuan Xu zhe mei zhe Qian Yong-Ning Zhou Department of materials Science Fudan UniversityShanghai 200433China Shanghai Xuanyi New Energy Development Co. LtdShanghai 201800China Global Institute of Future Technology Shanghai Jiao Tong UniversityShanghai 200240China

The balance between cationic redox and oxygen redox in layer-structured cathode materials is an important issue for sodium batteries to obtain high energy density and considerable cycle *** redox can contribute extra capacity to increase energy density,but results in lattice instability and capacity fading caused by lattice oxygen gliding and oxygen *** this work,reversible mn^(2+)/mn^(4+)redox is realized in a P3-Na_(0.65)Li_(0.2)Co_(0.05)mn_(0.75)O_(2)cathode material with high specific capacity and structure stability via Co *** contribution of oxygen redox is suppressed significantly by reversible mn^(2+)/mn^(4+)redox without sacrificing capacity,thus reducing lattice oxygen release and improving the structure *** X-ray techniques reveal that P3 phase is well maintained in a wide voltage window of 1.5-4.5 V ***^(+)/Na even at 10 C and after long-term *** is disclosed that charge compensation from Co/mn-ions contributes to the voltage region below 4.2 V and O-ions contribute to the whole voltage *** synergistic contributions of mn^(2+)/mn^(4+),Co^(2+)/Co^(3+),and O^(2-)/(O_n)^(2-)redox in P3-Na_(0.65)Li_(0.2)Co_(0.05)mn_(0.75)O_(2)lead to a high reversible capacity of 215.0 m A h g^(-1)at 0.1 C with considerable cycle *** strategy opens up new opportunities for the design of high capacity cathode materials for rechargeable batteries.

关键词： Sodium batteries Cathode materials Layered structure Co substitution

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d-d Orbital coupling induced by crystal-phase engineering assists acetonitrile electroreduction to ethylamine

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Journal of Energy Chemistry 2024年第2期89卷 216-225,I0006页

作者： Honggang Huang Yao Chen Hui Fu Cun Chen Hanjun Li zhe zhang Feili Lai Shuxing Bai Nan zhang Tianxi Liu Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122JiangsuChina Department of Chemistry KU LeuvenCelestijnenlaan 200FLeuven 3001Belgium College of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266071ShandongChina

The d-d orbital coupling induced by crystal-phase engineering can effectively adjust the electronic structure of electrocatalysts,thus showing significant catalytic performance,while it has been rarely explored in electrochemical acetonitrile reduction reaction(ARR)to ***,we successfully realize the structural transformation of Pd Cu metallic aerogels(mAs)from face-centered cubic(FCC)to body-centered cubic(BCC)through annealing ***,the BCC Pd Cu mAs exhibit excellent ARR performance with high ethylamine selectivity of 90.91%,Faradaic efficiency of 88.60%,yield rate of 316.0 mmol h^(-1)g^(-1)_(Pd+Cu)and long-term stability for consecutive electrolysis within 20 h at-0.55 V *** hydrogen electrode,outperform.ng than those of FCC Pd Cu *** the membrane electrode assembly system,BCC Pd Cu mAs also demonstrate excellent ethylamine yield rate of 389.5 mmol h^(-1)g^(-1)_(Pd+Cu).Density functional theory calculation reveals that the d-d orbital coupling in BCC Pd Cu mAs results in an evident correlation effect for the interaction of Pd and Cu sites,which boosts up the Cu sites electronic activities to enhance ARR *** work opens a new route to develop efficient ARR electrocatalysts from the perspective of crystalline structure transformation.

关键词： d-d Orbital coupling Crystal-phase engineering metallic aerogels Acetonitrile electroreduction reaction Ethylamine

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Three-year field study on grass growth and soil hydrological properties in biochar-amended soil

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Journal of Rock mechanics and Geotechnical Engineering 2024年第7期16卷 2764-2774页

作者： Haowen Guo Charles Wang Wai ng Junjun Ni Qi zhang Yuchen Wang Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina School of Transportation Southeast UniversityNanjingChina

Field monitoring was conducted to investigate and quantify the long-term effects of peanut shell biochar on soil-grass interaction over three *** 10 m5 m grassed plots were constructed in completely decomposed granitic *** of them were amended,respectively,with 5%and 10%biochar contents(m^(3)/m^(3))for grass growth,while the third was without biochar *** the threeyear monitoring,plant characteristics,saturated water permeability(k_(s))of grassed soil and soil suction were *** monitored results show that the grass leaf area index(LAI)and root length density(RLD)with biochar amendment were improved by 38%and 200%,*** the grassed plot without biochar,a threshold RLD existed with a value of 1.7 cm/cm^(3),beyond which k_(s) raised *** threshold RLD increased by 52%when biochar content increased from 0%to 10%.This implies that biochar may restrict the increase in k_(s) of grassed soil due to the rise in the threshold *** presence of biochar and grass can retain over 100%higher suction after heavy rainfalls,while 54%lower peak suction under evapotranspiration(ET)compared with the non-amended *** can alleviate the negative effects on hydraulic properties caused by plant growth and reduce ET-induced excessive water loss.A 5%peanut shell biochar content is recommended for the long-term management of vegetated earthen infrastructures.

关键词： Soil-grass interaction Biochar Long-term Water infiltration Soil drying

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Experimental study on the variation of optical remote sensing imaging characteristics of internal solitary waves with wind speed

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Journal of Oceanology and Limnology 2024年第2期42卷 408-420页

作者： zhe CHAng Lina SUN Tengfei LIU m.ng zhang Keda LIAng Junmin m.ng Jing WAng School of Physics and Optoelectronic Engineering Ocean University of ChinaQingdao 266100China First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China Technology Innovation Center for Ocean Telemetry Ministry of Natural ResourcesQingdao 266061China

Optical remote sensing has been widely used to study internal solitary waves(ISWs).Wind speed has an important effect on ISW imaging of optical remote *** light and dark bands of ISWs cannot be observed by optical remote sensing when the wind is too *** relationship between the characteristics of ISWs bands in optical remote sensing images and the wind speed is still *** influence of wind speeds on the characteristics of the ISWs bands is investigated based on the physical simulation experiments with the wind speeds of 1.6,3.1,3.5,3.8,and 3.9 m/*** experimental results show that when the wind speed is 3.9 m/s,the ISWs bands cannot be observed in optical remote sensing images with the stratification of h_(1)∶h_(2)=7∶58,ρ_(1)∶ρ_(2)=1∶*** the wind speeds are 3.1,3.5,and 3.8 m/s,which is lower than 3.9 m/s,the ISWs bands can be obtained in the simulated optical remote sensing *** location of the band’s dark and light extremum and the band’s peak-to-peak spacing are almost not affected by wind ***-significant wind speeds can cause a greater gray difference of the light-dark *** provided a scientific basis for further understanding of ISW optical remote sensing imaging.

关键词： internal solitary wave(ISW) optical remote sensing wind speed characteristics of ISWs bands

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Large contributions of emission reductions and meteorological conditions to the abatement of Pm_(2.5)in Beijing during the 24th Winter Olympic Games in 2022

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Journal of Environmental Sciences 2024年第2期136卷 172-188页

作者： Yaping Jiang Shaocai Yu Xue Chen Yibo zhang m.ngying Li zhen Li zhe Song Pengfei Li Xiaoye zhang Eric Lichtfouse Daniel Rosenfeld Key Laboratory of Environmental Remediation and Ecological Health Ministry of EducationResearch Center for Air Pollution and HealthCollege of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China College of Science and Technology Hebei Agricultural UniversityBaoding 071000China Chinese Academy of meteorological Sciences China Meteorological AdministrationBeijing 100081China Aix-marseille Univ CNRSColl FranceCNRSIRDINRAEEuropole Mediterraneen de l’ArboisAvenue Louis Philibert13100 Aix en ProvenceFrance Xi’an Jiaotong University State Key Laboratory of Multiphase Flow in Power EngineeringXi’an 710049China Institute of Earth Sciences The Hebrew University of JerusalemJerusalemIsrael

To guarantee the blue skies for the 2022 Winter Olympics held in Beijing and zhangjiakou from February 4 to 20,Beijing and its surrounding areas adopted a series of emission control *** provides an opportunity to determine the impacts of large-scale temporary control measures on the air quality in Beijing during this special ***,we applied the WRF-CmAQ model to quantify the contributions of emission reduction measures and meteorological *** show that meteorological conditions in 2022 decreased Pm_(2.5)in Beijing by 6.9 and 11.8μg/m^(3)relative to 2021 under the scenarios with and without emission reductions,*** emission reduction measures implemented in Beijing and seven neighboring provinces resulted in an average decrease of 13.0μg/m^(3)(-41.2%)in Pm_(2.5)in *** the entire period,local emission reductions contributed more to good air quality in Beijing than nonlocal emission *** the emission reduction scenario,local,controlled regions,other regions,and boundary conditions contributed 47.7%,42.0%,5.3%,and 5.0%to the Pm_(2.5)concentrations in Beijing,*** results indicate that during the cleaning period with the air masses from the northwest,the abatements of Pm_(2.5)were mainly caused by local emission ***,during the potential pollution period with the air masses from the east-northeast and west-southwest,the abatements of Pm_(2.5)were caused by both local and nonlocal emission reductions almost *** implies that regional coordinated prevention and control strategies need to be arranged scientifically and rationally when heavy pollution events are forecasted.

关键词： Pm_(2.5) WRF-CmAQ meteorological conditions Emission reductions Winter Olympic games

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