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Can near-to-mid Infrared Spectral Energy Distribution Quantitatively Trace Protoplanetary Disk Evolution?

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Research in Astronomy and Astrophysics 2024年第7期 37-49页

作者：刘明超何金华 zhen guo 葛继兴唐雨平 Shanghai Key Lab for Astrophysics Shanghai Normal University yunnan Observatories Chinese Academy of Sciences Chinese Academy of Sciences South America Center for Astronomy National Astronomical ObservatoriesChinese Academy of Sciences University of Chinese Academy of Sciences Departamento de Astronomía Universidad de Chile Instituto de Física y Astronomía Universidad de Valparaíso Centre for Astrophysics Research University of Hertfordshire Millennium Institute of Astrophysics Xinjiang Astronomical Observatory Chinese Academy of Sciences Xinjiang Key Laboratory of Radio Astrophysics

Infrared(IR) spectral energy distribution(SED) is the major tracer of protoplanetary disks. It was recently proposed to use the near-to-mid IR(or K-24) SED slope α defined between 2 and 24μm as a potential quantitative tracer of disk age. We critically examine the viability of this idea and confront it with additional statistics of IR luminosities and SED shapes. We point out that, because the statistical properties of most of the complicated physical factors involved in disk evolution are still poorly understood in a quantitative sense, the only viable way is to assume them to be random so that an idealized “average disk” can be defined, which allows the α histogram to trace its age. We confirm that the statistics of the zeroth order(luminosity), first order(slope α), and second order characteristics(concavity) of the observed K-24 SEDs indeed carry useful information upon the evolutionary processes of the “average disk”. We also stress that intrinsic diversities in K-24 SED shapes and luminosities are always large at the level of individual stars so that the application of the evolutionary path of the “average disk” to individual stars must be done with care. The data of most curves in plots are provided on GitHub(Disk-age package https://***/starage/disk-age/).

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Dark Matter Search in Dwarf Irregular Galaxies with Ten Years of Data from the Ice Cube Neutrino Observatory

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Research in Astronomy and Astrophysics 2024年第3期24卷 75-82页

作者： Yi-Fei Lü Ben-Yang Zhu Rong-Lan Li Xue-Kang guo Tian-Ci Liu Yong-Bo Huang yun-Feng Liang Guangxi Key Laboratory for Relativistic AstrophysicsSchool of Physical Science and TechnologyGuangxi University Nanning 530004China

Dwarf irregular galaxies(dIrrs),as rotationally supported systems,have more reliable J-factor measurements than dwarf spheroidal galaxies and have received attention as targets for dark matter detection in recent *** this paper,we use 10 yr of IceCube muon-track data and an unbinned maximum-likelihood-ratio method to search for neutrino signals beyond the background from the directions of seven dIrrs,aiming to detect neutrinos produced by heavy annihilation dark *** do not detect any significant *** on such null results,we calculate the upper limits on the velocity-averaged annihilation cross section for 1 TeV–10 PeV dark *** limits,although weaker than the strictest constraints in the literature in this mass range,are also a good complement to the existing results considering the more reliable J-factor measurements of dIrrs.

关键词： (cosmology) dark matter-cosmology theory-galaxies dwarf

Emerging direct current triboelectric nanogenerator for high-entropy mechanical energy harvesting

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Science China(Technological Sciences) 2024年第5期67卷 1297-1316页

作者： CHEN Jie guo RuiLong guo HengYu College of Physics and Electronic Engineering Chongqing Normal UniversityChongqing 401331China Department of Applied Physics Chongqing UniversityChongqing 401331China

In the era of the Internet of Things(IoT),the provision of sustainable power to distributed,mobile,and low-power-consumption electronic devices is a critical *** overcome this challenge,the triboelectric nanogenerator(TENG),a highly efficient high-entropy mechanical energy harvesting device,was developed in *** device enables the direct conversion of irregular and low-frequency mechanical energy into pulsed alternating current(AC)***,the incompatibility of most electronic devices with AC signals necessitates rectifier circuits or generators that deliver direct current(DC)*** recent years,DC-TENGs have undergone extensive development,achieving significant milestones in various application fields while also facing crucial challenges that require *** this review,three categories of DC-TENG devices with distinct operating mechanisms are comprehensively explored:multiphase coupling,mechanical rectification,and air *** typical structures and working mechanisms are thoroughly discussed,and specific output performance limitations,along with corresponding optimization strategies,are ***,the applications of DC-TENGs in various scenarios are ***,the challenges faced by DC-TENGs and potential solutions are analyzed to guide further advancements in this technology.

关键词： TENG direct current working mechanisms output performance limitations optimization strategies

Spatiotemporal variations in glacier area and surface velocity of the northern Antarctic Peninsula during 2018-2022

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Advances in Climate Change Research 2024年第2期15卷 297-311页

作者： Yu-Long KANG Shi-Chang KANG Wan-Qin guo Tao CHE Zong-Li JIANG zhen-Feng WANG Qiang-Qiang XU Cheng-De YANG State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100083China Key Laboratory of Remote Sensing of Gansu Province Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China School of Earth Sciences and Spatial Information Engineering Hunan University of Science and TechnologyXiangtan 411201China

Ice sheet serves as a crucial indicator for assessing climate *** loss in recent remote sensing-based studies indicated that the Antarctic Peninsula has rapid rates of glacier retreat and speed up of surface ***,observations of seasonal variability of ice speed are limited,and glacier-area changes require multi-temporal *** study investigated the changes in area and surface velocities of∼375 glaciers on the northern Antarctic Peninsula(NAP)utilizing satellite images acquired by the Sentinel 1&2 satellites during *** results indicate that the glacier area reduced by approximately 166.1±44.2 km^(2)(-0.2%±0.1%per year)during the study period,with an acceleration after 2020(-0.4%±0.3%per year),and the most dramatic reduction happened on the eastern *** maximum annual ice speeds on the NAP generally exceeded 3500 m per year,while the ice speeds in 2021 were the highest(exceeded 4210 m per year).The ice speed variability in austral autumn was higher than in other seasons,meanwhile the summer ice speeds showed an increasing *** glacier G012158E47018N,McNeile Glacier,glacier G299637E64094S and Drygalski Glacier showed the most remarkable ice speed variations represented by high daily velocities and strong fluctuations on their *** results demonstrated that the variations in glacier area and seasonal ice speed on the NAP were responsive to the ice-ocean-atmosphere ***,seasonal velocity and area variations should be considered when conducting accurate mass balance calculations,model validations and change mechanism analyses under climate warming scenarios.

关键词： Glacier area Seasonal ice speed Sentinel 1&2 Northern Antarctic Peninsula Ice-ocean-atmosphere processes

Effect of cerium alloying on microstructure,texture and mechanical properties of magnesium during cold-rolling process

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Journal of Rare Earths 2024年第5期42卷 1001-1008,I0007页

作者： zhen Zhang Huanhuan Chen Shiju Cao Jinhua Peng Peng guo Chang Long Shan Wang Chang Chen Yong Wu Ji'an Huang Xiaodong Du Haigen Wei School of Materials Science and Engineering Hefei University of TechnologyHefei230009China NationalLocal Joint Research Center of Non-ferrous Metal Materials and Processing Technology Hefei230009China Laboratory of Nonferrous Metal Material and Processing Engineering of Anhui Province Hefei230009China School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212003China Institute of Industry and Equipment Technology Hefei University of TechnologyHefei230009China Faculty of Materials Metallurgy and Chemistry Jiangxi University of Science and TechnologyGanzhou341000China

Hot-extrusion and cold-rolling were conducted on Mg-Ce binary alloys to explore the effect of cerium(Ce)on microstructure,texture and mechanical properties of Mg *** addition of Ce results in significant grain refinement both in as-cast and hot-extruded *** basal texture is also weakened after extrusion and an inclined basal texture is formed with Ce *** strength and elongation of the Mg-Ce alloys are improved simultaneously due to such grain refinement and texture weakening *** cold-rolling,plenty of twins are found in the pure Mg and AZ31 plates while grains in the Mg-0.3Ce plate deform more uniformly without lamellar twin ***,Mg-0.3Ce alloys own strong and continuous strain hardening because Ce atoms and Mg-Ce precipitated phases serve as obstacles for dislocation slip.

关键词： Mg-Ce alloys Hot extrusion Cold-rolling Rare earths

Host cyclophilin A facilitates SARS-CoV-2 infection by binding and stabilizing spike on virions

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Signal Transduction and Targeted Therapy 2024年第1期9卷 36-39页

作者： Xiangpeng Sheng Fang Zhu Hong Peng Fan Yang Yi Yang Cong Yang zhen Wang Wei Chen Deyin guo Ronggui Hu State Key Laboratory of Molecular Biology Center for Excellence in Molecular Cell ScienceShanghai Institute of Biochemistry and Cell BiologyUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghaiChina MOE Key Laboratory of Tropical Disease Control Centre for Infection and Immunity StudySchool of MedicineSun Yat-sen UniversityShenzhenChina ICU Longhua Hospital Shanghai University of Traditional Chinese MedicineShanghaiChina

Dear Editor,The novel coronavirus SARS-CoV-2 rapidly evolutes to increase its infectivity and transmissibility,facilitates its immune escape,impairs vaccine efficacy,and currently causes repeated infections in human,which is mainly determined by the accumulated mutations in spike(S).1 Transmembrane S is a heavily glycosylated protein on the surface of the virion as homotrimer,responsible for binding to human angiotensin-converting enzyme 2(hACE2)receptor.2 While the architecture of S trimers has been well studied,how the stability of S is regulated by potential host factors remains unknown.

关键词： ACE2 vaccine infection

Tuning interaction strength between CeO_(2) and iridium to promote CO oxidation over Ir/TiO_(2)

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Journal of Rare Earths 2024年第4期42卷 651-659页

作者： Lu Dai Binghua Li Yuhan Peng Xianwei Hao Runquan Xuan Hua Huang Yiming Bi Liping Xu Yanhui Zhang yun guo Fangqi Du Li Wang Hui Wang Technology Center China Tobacco Zhejiang Industrial Co.Ltd.Hangzhou310024China Research Institute of Industrial Catalysis East China University of Science and TechnologyShanghai200237China

The interaction between support and noble metal plays a crucial role in heterogeneous catalysis ***,how to tune metal support interactions to optimize the activity still needs further ***_(2) was introduced to promote CO oxidation ove r Ir/TiO_(2) by adjusting the interaction strength between iridium(Ir)and CeO_(2).The strong interaction between Ir and CeO_(2) blocks CO adsorption and causes low CO oxidation ***,introducing CeO_(2) on Ir/TiO_(2) produces localized interaction between Ir and CeO_(2),which can tune the surface electronic state of Ir,so a"volcano curve"relationship between CO oxidation activity and electronic state is *** amount of CeO_(2) on Ir/TiO_(2)(Ir/Ce_(0.2)Ti)leads to CO complete oxidization at 22℃,and a new pathway for CO oxidation was *** study demonstrates that the utilization of tuning interaction strength between active metal and support is a potential method to increase the catalytic activity.

关键词： CO oxidation CeO_(2) Localized interaction Interaction strength Supported Ir catalysts Rareearths

Physicochemical principles of hydrogen metallurgy in blast furnace

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Journal of Iron and Steel Research(International) 2024年第1期31卷 46-63页

作者： Han-jie guo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing100083China

Based on the stoichiometric method and the free energy minimization method,an ideal model for the reduction of iron oxides by carbon and hydrogen under blast furnace conditions was established,and the reduction efficiency and theoretical energy consumption of the all-carbon blast furnace and the hydrogen-rich blast furnace were *** results show that after the reduction reaction is completed at the bottom of the blast furnace,the gas produced by reduction at 1600℃still has a certain excessive reduction capacity,which is due to the hydrogen brought in by the hydrogen-rich blast as well as the excess carbon monoxide generated by the reaction of the coke and the oxygen brought in by the *** the process of the gas with excessive reduction capacity rising from the bottom of the blast furnace and gas reduction process,the excessive reduction capacity of the gas gradually decreases with the increase in the dydrogen content in the *** the all-carbon blast furnace,the excess gas reduction capacity is the strongest,and the total energy consumption per ton of iron reduction is the *** shows that,for the current operation mode of the blast furnace,adding hydrogen in the blast furnace cannot reduce the consumption of carbon required for reduction per ton of iron,but rather increases the consumption of carbon.

关键词： Hydrogen metallurgy Excess gas reduction capacity Theoretical energy consumption Hydrogen-rich blast furnace Thermodynamic model Gibbs minimum free energy method

Heterointerface engineering of assembled CoP_(2) on N-modified carbon as efficient trifunctional electrocatalysts for Zn-Air batteries and overall water splitting

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Nano Research 2024年第5期17卷 3801-3809页

作者： Yan Chen zhenrui Yang Juan Wang yun Yang Xuedong He Yang Wang Jiadong Chen Yaqing guo Xin Wang Shun Wang Huile Jin Wenzhou Key Lab of Advanced Energy Storage and Conversion Zhejiang Province Key Lab of Leather EngineeringCollege of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035China Zhejiang Engineering Research Center for Electrochemical Energy Materials and Devices Institute of New Materials and Industrial TechnologiesWenzhou UniversityWenzhou 325035China School of Chemical and Biomedical Engineering Nanyang Technological UniversitySingapore 637459Singapore

Enhancing catalytic activity through modulating the interaction between N-doped carbon and metal phosphides clusters is an effective ***,the electronic structure modulation of CoP_(2) supported N-modified carbon(CoP_(2)/NC)has been designed and prepared as efficient electrocatalysts for oxygen reduction reaction(ORR),oxygen evolution reaction(OER),and hydrogen evolution reaction(HER).Notably,CoP_(2)/NC-1 catalyst exhibits impressive performance in alkaline media,with an ORR half-wave potential of 0.84 V,as well as OER and HER overpotentials of 290 and 129 mV(at 10 mA·cm^(−2)),*** addition,CoP_(2)/NC-1 produces a power density as high as 172.9 mW·cm^(−2),and excellent reversibility of 100 h at 20 mA·cm^(−2) in home-made Zn-air *** experimental results demonstrate that the synergistic interactions between N modified carbon substrate and CoP_(2) material significantly enhance the kinetics of ORR,OER,and *** functional theory(DFT)calculations reveal the strong electrons redistribution of CoP_(2) induced by high-density N atoms at the interface,thus optimizing the key intermediates and significantly lower the energy barrier of *** electronic adjustments of CoP_(2) greatly enhance its kinetics of ORR/OER/HER,leading to faster *** study provides profound insights into the specific modification of CoP_(2) by N-doped carbon,enabling the construction of efficient catalysts.

关键词： two-dimensional(2D)carbon metal-organic framework cobalt phosphide zinc air battery water splitting