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Is the Gum Nebula an important interstellar scattering disk of background pulsars?

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Science China(Physics,Mechanics & Astronomy) 2025年第3期68卷 175-186页

作者： Rui Wang Zhen Yan Zhiqiang Shen Ke Jia Lee Yajun Wu Rongbing Zhao Zhipeng Huang Xiaowei Wang Jie Liu Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai200030China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing100049China Key Laboratory of Radio Astronomy and Technology Chinese Academy of SciencesBeijing100101China School of physical Science and Technology ShanghaiTech UniversityShanghai201210China Department of Astronomy School of PhysicsPeking UniversityBeijing100871China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing100871China Department of Physics and Astronomy Hubei University of EducationWuhan430205China

The Gum Nebula is a faint supernova remnant extending about 40°across the southern sky,potentially affecting tens of background *** the view that the Gum Nebula acts as a potential scattering screen for background pulsars has been recurrently mentioned over the past five decades,it has not been directly *** chose the strong background pulsar PSR B0740-28 as a probe and monitored its diffractive interstellar scintillation(DISS)at 2.25&8.60 GHz simultaneously for about two years using the Shanghai Tian Ma Radio Telescope(TMRT).DISS was detected at both frequencies and quantified by two-dimensional autocorrelation *** calculated their scattering spectral indexαand found that 9/21 of the observations followed the theoretical predictions,while 4/21 of them clearly showedα<*** finding provides strong support for anomalous scattering along the pulsar line of sight,due to the large frequency lever arm and the simultaneous features of our dual-frequency *** comparison to the 2.25 GHz observations,scintillation arcs were observed in 10/21 of the secondary spectrum plots for 8.60 GHz ***,the highest frequency record for pulsar scintillation arc detection was updated to 8.60 *** fitting results were the most direct evidence for the view that the Gum Nebula acts as the scattering screen for background pulsars,because both the distance(245_(-72)^(+69)pc)and transverse speed(22.4_(-4.2)^(+4.1)km s^(-1))of the scintillation screen are comparable with related parameters of the Gum *** findings indicated that anisotropic scattering provides a superior explanation for the annual modulation of scintillation arcs than isotropic ***,the orientation of its long axis was also fitted.

关键词： pulsar interstellar scintillation Gum Nebula

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Predicting peak ground acceleration using the ConvMixer network

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Earthquake Science 2025年第2期38卷 126-135页

作者： Mona Mohammed Omar M Saad Arabi Keshk Hatem M Ahmed National Research Institute of Astronomy and Geophysics(NRIAG) Cairo 11511Egypt Division of physical Science and Engineering King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia Delta Technological University Menoufia 32684Egypt faculty of Computers and Information Menoufia UniversityMenoufia 32512Egypt

The level of ground shaking,as determined by the peak ground acceleration(PGA),can be used to analyze seismic hazard at a certain location and is crucial for constructing earthquake-resistant *** the PGA immediately after an earthquake occurs allows for the issuing of a warning by an earthquake early warning *** this study,we propose a deep learning model,ConvMixer,to predict the PGA recorded by weak-motion velocity seismometers in *** use 5-s threecomponent seismograms,from 2 s before until 3 s after the P-wave arrival time of the *** dataset comprised more than 50,000 single-station waveforms recorded by 10 seismic stations in the K-NET,Kiki-NET,and Hi-Net networks between 2004 and *** proposed ConvMixer is a patch-based model that extracts global features from input seismic data and predicts the PGA of an earthquake by combining depth and pointwise *** proposed ConvMixer network had a mean absolute error of 2.143 when applied to the test set and outperformed benchmark deep learning *** addition,the proposed ConvMixer demonstrated the ability to predict the PGA at the corresponding station site based on 1-second waveforms obtained immediately after the arrival time of the P-wave.

关键词： peak ground acceleration(PGA) earthquake early warning system(EEWS) deep learning(DL)

Unintentional emissions of polychlorinated naphthalenes in China:Sources,composition,and historical trends

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Journal of Environmental Sciences 2025年第2期148卷 221-229页

作者： Ye Huang Lin Huang Ying Li Nazupar Sidikjan Yunshan Zhang Yan Chen Yangmin Chen Ye Li Wei Du Long Chen YanWu Shanshan Zhang Jing Yang Wenjun Meng Guofeng Shen Min Liu Shu Tao Key Laboratory of Geographic Information Science of the Ministry of education School of Geographic SciencesEast China Normal UniversityShanghai 200241China Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control Faculty of Environmental Science&EngineeringKunming University of Science&TechnologyKunming 650500China Laboratory of Earth Surface Processes College of Urban and Environmental SciencePeking UniversityBeijing 100871China

Polychlorinated naphthalenes(PCNs)are detrimental to human health and the *** the commercial production of PCNs banned,unintentional releases have emerged as a significant environmental ***,relevant information is still *** this study,provincial emissions for eight PCNs homologues from 37 sources in the Chinese mainland during the period of 1960-2019 were estimated based on a source-specific and time-varying emission factor *** results showed that the total PCNs emissions in 2019 reached 757.0 kg with Hebei ranked at the top among all the provinces and iron&steel industry as the biggest ***-chlorinated PCNs comprised 90%of emissions by mass,while highly chlorinated PCNs dominated in terms of toxicity,highlighting divergent priorities for mitigating emissions and safeguarding human *** emissions showed an overall upward trend from 1960 to 2019 driven by emission increase from iron&steel industry in terms of source,and from North China and East China in terms of geographic ***-capita emissions followed an inverted U-shaped environmental Kuznets curvewhile emission intensities decreased with increasing per-capita Gross Domestic Product(GDP)following a nearly linear pattern when log-transformed.

关键词： PCNs Emission inventory Emission factor Composition profile Emission intensity Chinese mainland

Enhanced oral drug delivery by mimicking natural amino acid and oligopeptide absorption route

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Nano Research 2025年第2期18卷 525-540页

作者： Ruinan Wu Xiaoxing Fan Licheng Wu Liyun Xing Jinxia Kong Zhou Zhou Jingyuan Wen Lian Li Yuan Huang Key Laboratory of Drug-Targeting and Drug Delivery System of the education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial TechnologyWest China School of PharmacySichuan UniversityChengdu 610041China School of Pharmacy Faculty of Medical and Health SciencesUniversity of AucklandAuckland 1023New Zealand

Oral delivery of protein and peptide drugs presents considerable challenges due to their susceptibility to digestive enzymes in gastrointestinal(Gl)tract and low efficiency of transepithelial ***,inspired by efficient absorption of protein-based nutrients,we constructed several kinds of oral drug delivery systems by mimicking natural amino acid and oligopeptide absorption *** kinds of amino acids and two kinds of oligopeptides were chosen as targeting ligands to mediate transportation of orally administered nanoparticles(NPs).Liraglutide(Lira),a kind of glucagon like peptide-1(GLP-1)receptor agonist,was used as model *** functionalized NPs could protect Lira from enzymatic degradation in Gl ***,compared with amino acid-modified NPs,oligopeptide-modified NPs exhibited greater transepithelial transport efficiency and were primarily absorbed in the proximal small intestine due to the high expression and transportation mediated by proton coupled oligopeptide transporter 1(PEPT1).These Lira-loaded NPs could effectively control the blood glucose level,reduce plasma lipid level,and repair tissue damage on type 2 diabetic mice and even showed comparable hypoglycemic effects of subcutaneous injection(s.c.)free *** study demonstrates the potential of mimicking natural oligopeptide absorption route to enhance oral delivery of protein and peptide drugs.

关键词： oral drug delivery amino acid absorption route oligopeptide absorption route liraglutide

Insights into the seasonal characteristics of single particle aerosols in Chengdu based on SPAMS

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Journal of Environmental Sciences 2025年第3期149卷 431-443页

作者： Junke Zhang Yunfei Su Chunying Chen Xinyi Fu Yuhan Long Xiaoxue Peng Xiaojuan Huang Gehui Wang Wei Zhang faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China Department of Environmental Science&Engineering Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention(LAP3)Fudan UniversityShanghai 200438China Key Lab of Geographic Information Science of the Ministry of education School of Geographic SciencesEast China Normal UniversityShanghai 200241China Sichuan Ecological Environment Monitoring Station Chengdu 610091China

To investigate the seasonal characteristics in air pollution in Chengdu,a single particle aerosol mass spectrometry was used to continuously observe atmospheric fine particulate matter during one-month periods in summer and winter,*** results showed that,apart from O_(3),the concentrations of other pollutants(CO,NO_(2),SO_(2),PM_(2.5)and PM_(10))were significantly higher in winter than in *** single particle aerosols were divided into seven categories:biomass burning(BB),coal combustion(CC),Dust,vehicle emission(VE),K mixedwith nitrate(K-NO_(3)),Kmixed with sulfate and nitrate(K-SN),and K mixedwith sulfate(K-SO_(4))*** highest contributions in both seasons were VE particles(24%).The higher contributions of K-SO_(4)(16%)and K-NO_(3)(10%)particles occurred in summer and winter,respectively,as a result of their different formation mechanisms.S-containing(KSO_(4)and K-SN),VE,and BB particles caused the evolution of pollution in both seasons,and they can be considered as targets for future pollution *** mixing of primary sources particles(VE,Dust,CC,and BB)with secondary components was stronger in winter than in *** summer,as pollution worsens,the mixing of primary sources particles with 62[NO_(3)]−weakened,but themixing with 97[HSO_(4)]−***,in winter,the mixing state of particles did not exhibit an obvious evolution *** potential source areas in summer were mainly distributed in the southern region of Sichuan,while in winter,besides the southern region,the contribution of the western region cannot be ignored.

关键词： Single particle aerosols Chemical composition Mixing state Regional transport Seasonal characteristics

Effective suppression of surface cation segregations on double perovskite oxides through entropy engineering

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Journal of Rare Earths 2025年第2期43卷 345-353,I0005页

作者： Zhe Wang Mengke Yuan Juntao Gao Hongru Hao Jingwei Li Lingling Xu Zhe Lv Bo Wei School of Physics Harbin Institute of TechnologyHarbin150001China faculty of Engineering University of Bayreuth95448BayreuthGermany State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China Key Laboratory of Photonic and Electric Band Gap Materials Ministry of EducationSchool of Physics and Electronic EngineeringHarbin Normal UniversityHarbin150025China

Cation segregation on cathode surfaces plays a key role in determining the activity and operational stability of solid oxide fuel cells(SOFCs).The double perovskite oxide PrBa_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(PBCC)has been widely studied as an active cathode but still suffer from serious detrimental *** enhance the cathode stability,a PBCC derived A-site medium-entropy Pr_(0.6)La_(0.1)Nd_(0.1)Sm_(0.1)Gd_(0.1)Ba_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(ME-PBCC)oxide was prepared and its segregation behaviors were investigated under different *** with initial PBCC oxide,the segregations of BaO and Co_(3)O_(4)on the surface of ME-PBCC material are significantly suppressed,especially for Co_(3)O_(4),which is attributed to its higher configuration *** results also confirm the improved electrochemical performance and structural stability of ME-PBCC material,enabling it as a promising cathode for SOFCs.

关键词： Solid oxide fuel cells Cathode Double perovskite Configuration entropy Cation segregation Rare earths

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Discovery of a new family member of arsenic–vanadium polyoxometalates with high catalytic performance for one-pot coupling of CO2, epoxides and amines

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Tungsten 2025年第1期7卷 80-87页

作者： Fang-Qian Wang Yin Zhang Wei-Wei Wang Mei-Qian Fu Hong-Bing Mo Wei-Dong Yu Chao Liu Jun Yan College of Chemistry and Chemical Engineering Central South University Junior education Department Changsha Normal University School of Science Hunan University of Technology and Business

Arsenic-vanadium polyoxometalates（POMs） represent a family of tremendous potential catalysts owing to their peculiar physical and chemical *** in CO2conversion,using POMs to catalyze the conversion of CO2and epoxide into chemical intermediates is the research ***,A new family number of arsenic-vanadium POMs,[N（CH3）4]4[As8V12O38（H2O）]·2H2O({As8V12O38}),was reported and characterized by single-crystal X-ray diffraction,fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy,*** from other allotropicity,{As8V12O38}shows a different structure pattern with an I-43d *** obtained {As8V12O38} was employed as a catalyst for the *** initial catalytic reaction confirmed that {As8V12O38} can catalyze the formation of epoxy carbonate by using 1.01 kPa CO2and epoxide at 70℃.Furtherly,when added amine in the catalytic system,oxazolidinone could be obtained by high yields,which provides an efficient way to convert CO2into profitable ***,a possible catalytic reaction mechanism was proposed by using different characterization analyses.{As8V12O38} first catalyzes the epoxide and CO2to form an epoxy carbonate and then catalyzes epoxy carbonate and benzylamine into oxazolidinone.

关键词： Arsenic CO2 conversion Oxazolidinone Polyoxometalates Vanadium

Direct seawater splitting for hydrogen production:Recent advances in materials synthesis and technological innovation

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Green Energy & Environment 2025年第1期10卷 11-33页

作者： Yilin Zhao Zhipeng Yu Aimin Ge Lujia Liu Joaquim Luis Faria Guiyin Xu Meifang Zhu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Center for Advanced Low-dimension MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai201620China International Iberian Nanotechnology Laboratory(INL) Avenida Mestre Jose VeigaBraga4715-330Portugal The MacDiarmid Institute for Advanced Materials and Nanotechnology School of Chemical and Physical SciencesVictoria University of WellingtonWellington6012New Zealand LSRE-LCM-Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials Faculty of EngineeringUniversity of PortoRua Dr.Roberto Frias s/nPorto4200-465Portugal ALiCE-Associate Laboratory in Chemical Engineering Faculty of EngineeringUniversity of PortoRua Dr.Roberto Frias s/nPorto4200-465Portugal

Direct seawater splitting has emerged as a popular and promising research direction for synthesising clean,green,non-polluting,and sustainable hydrogen energy without depending on high-purity water in the face of the world’s shortage of fossil ***,efficient seawater splitting is hindered by slow kinetics caused by the ultra-low conductivity and the presence of bacteria,microorganisms,and stray ions in ***,producing hydrogen on an industrial scale is challenging due to the high production *** present review addresses these challenges from the catalyst point of view,namely,that designing catalysts with high catalytic activity and stability can directly affect the rate and effect of seawater *** the ion transfer perspective,designing membranes can block harmful ions,improving the stability of seawater *** the energy point of view,mixed seawater systems and self-powered systems also provide new and low-energy research systems for seawater ***,ideas and directions for further research on direct seawater splitting in the future are pointed out,with the aim of achieving low-cost and high-efficiency hydrogen production.

关键词： Seawater splitting Catalyst Membranes Mixed seawater systems Self-powered systems

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Adjusting *CO adsorption configuration over tandem trimetallic AuAgCu heterojunction boosts CO_(2) electroreduction to ethanol via asymmetric C–C coupling

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Science China Materials 2025年第1期68卷 173-179页

作者： Yongxia Shi Junjun Li Zhiwen Min Xinyi Wang Man Hou Hao Ma Zechao Zhuang Yuchen Qin Yuanmiao Sun Dingsheng Wang Zhicheng Zhang Key Laboratory of Organic Integrated Circuit Ministry of Education&Tianjin Key Laboratory of Molecular Optoelectronic SciencesDepartment of ChemistrySchool of ScienceTianjin UniversityTianjin 300072China faculty of Materials Science and Energy Engineering/Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Department of Chemistry Tsinghua UniversityBeijing 100084China College of Sciences Henan Agricultural UniversityZhengzhou 450000China

Rationally modulating the adsorption configuration of the key*CO intermediate could facilitate carbon±carbon(C±C)coupling to generate multi-carbon products in the electrochemical CO_(2) reduction *** this work,theoretical calculations reveal that C±C coupling via atopadsorbed*CHO and hollow-adsorbed*CO over Cu sites is an energetically favorable *** a proof of concept,a tandem trimetallic AuAgCu heterojunction(Au@Ag/Cu)was prepared,where the atop-adsorbed*CO over Au@Ag sites could migrate to Cu sites with hollow adsorption configuration,and then the asymmetric C±C coupling via transferred hollow-adsorbed*CO and existed atop-adsorbed*CHO over Cu sites facilitates the formation of the ethanol product,exhibiting a maximum Faraday efficiency of 65.9%at a low potential of−0.3 V *** hydrogen *** work provides new insights into the intrinsic understanding of tandem catalysis by regulating adsorption configuration of the intermediate products.

关键词： CO_(2)electroreduction C–C coupling tandem catalysis adsorption configuration ethanol