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Seasonal Characteristics of Forecasting Uncertainties in Surface PM_(2.5)Concentration Associated with Forecast Lead Time over the Beijing-Tianjin-Hebei Region

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Advances in Atmospheric sciences 2024年第5期41卷 801-816页

作者： Qiuyan DU Chun ZHAO Jiawang FENG Zining YANG Jiamin XU Jun GU Mingshuai ZHANG Mingyue XU Shengfu LIN Deep Space Exploration Laboratory/School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Comparative Planetology University of Science and Technology of ChinaHefei 230026China

Forecasting uncertainties among meteorological fields have long been recognized as the main limitation on the accuracy and predictability of air quality ***,the particular impact of meteorological forecasting uncertainties on air quality forecasts specific to different seasons is still not well *** this study,a series of forecasts with different forecast lead times for January,April,July,and October of 2018 are conducted over the Beijing-Tianjin-Hebei(BTH)region and the impacts of meteorological forecasting uncertainties on surface PM_(2.5)concentration forecasts with each lead time are *** increased lead time,the forecasted PM_(2.5)concentrations significantly change and demonstrate obvious seasonal *** general,the forecasting uncertainties in monthly mean surface PM_(2.5)concentrations in the BTH region due to lead time are the largest(80%)in spring,followed by autumn(~50%),summer(~40%),and winter(20%).In winter,the forecasting uncertainties in total surface PM_(2.5)mass due to lead time are mainly due to the uncertainties in PBL heights and hence the PBL mixing of anthropogenic primary *** spring,the forecasting uncertainties are mainly from the impacts of lead time on lower-tropospheric northwesterly winds,thereby further enhancing the condensation production of anthropogenic secondary particles by the long-range transport of natural *** summer,the forecasting uncertainties result mainly from the decrease in dry and wet deposition rates,which are associated with the reduction of near-surface wind speed and precipitation *** autumn,the forecasting uncertainties arise mainly from the change in the transport of remote natural dust and anthropogenic particles,which is associated with changes in the large-scale circulation.

关键词： PM_(2.5) forecasting uncertainties forecast lead time meteorological fields Beijing-Tianjin-Hebei region

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Low-temperature-pyrolysis preparation of nanostructured graphite towards rapid potassium storage with high initial Coulombic efficiency

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Nano Research 2024年第6期17卷 5138-5147页

作者： Jingke Ren Boyu Xing Wen Luo Binyang Luo Xinfei Wu Xin Yan Wencong Feng Feiyue Wang Chaojie Cheng Liqiang Mai State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Department of Physics School of ScienceWuhan University of TechnologyWuhan 430070China

Industrially prepared artificial graphite(AG)is attractive for potassium-ion batteries(PIBs),but its rate performance is poor and the production process is energy intensive,so developing an efficient strategy to produce novel graphite with low energy consumption and high performance is economically ***,a nanostructured graphite composed of multi-walled carbon nanotubes(MWCNTs)and graphite shells was prepared by one-pot method through low-temperature pyrolysis of iron-based metal-organic framework(MOF)and carbon *** high graphitization degree of nanostructured graphite makes the initial Coulombic efficiency(ICE)exceed 80%,and the three-dimensional(3D)conductive network ensures a specific capacity of 234 mAh·g^(−1)after 1000 cycles at a high current density of 500 mA·g^(−1).In addition,the typical graphite potassium storage mechanism is also demonstrated by in situ X-ray diffraction(XRD)and in situ Raman spectroscopy,and its practicality is also proved by the voltage of the full *** work provides a feasible way to optimize the practical production process of AG and expand its application in energy storage.

关键词： graphite anode potassium-ion batteries high graphitization degree low-temperature pyrolysis initial Coulombic efficiency

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Surface-sensitive electronic structure of kagome superconductor CsV_(3)Sb_(5)

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Chinese physics B 2024年第10期33卷 35-40页

作者： Zhisheng Zhao Jianghao Yao Rui Xu Yuzhe Wang Sen Liao Zhengtai Liu Dawei Shen Shengtao Cui Zhe Sun Yilin Wang Donglai Feng Juan Jiang School of Emerging Technology and Department of Physics University of Science and Technology of ChinaHefei 230026China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China National Synchrotron Radiation Laboratory School of Nuclear Science and Technology and New Cornerstone Science LaboratoryUniversity of Science and Technology of ChinaHefei 230026China

We systematically study the electronic structure of a kagome superconductor CsV_(3)Sb_(5)at different temperatures coveringboth its charge density wave state and normal state with angle-resolved photoemission *** observe thatthe V-shaped band aroundГshows three different behaviors,referred to as a/a',βandγ,mainly at different *** investigations confirm that these bands are all from the same bulk Sb-p_(z)origin,but they are quite sensitiveto the sample surface conditions mainly modulated by ***,the intriguing temperature dependent electronicbehavior of the band nearГis affected by the sample surface condition,rather than intrinsic electronic behavior originatingfrom the phase *** result systematically reveals the confusing electronic structure behavior of the energy bandsaroundГ,facilitating further exploration of the novel properties in this material.

关键词： kagome ARPES charge density wave surface sensitive

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Layout optimization and performance analysis of large array of imaging atmospheric Cherenkov telescopes

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Chinese physics C 2025年第3期49卷 161-170页

作者： Zhipeng Zhang Ruizhi Yang Shoushan Zhang Zhen Xie Jiali Liu Liqiao Yin Yudong Wang Lingling Ma Zhen Cao School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaHefei 230026China Deep Space Exploration Laboratory/School of Physical Sciences University of Science and Technology of ChinaHefei 230026China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsBeijing 100049China Department of Physics University of Chinese Academy of SciencesBeijing 100049China Tianfu Cosmic Ray Research Center Chengdu 610299China

The large array of imaging atmospheric Cherenkov telescopes(LACT)is a planned array of 32 Cherenkov telescopes,each featuring 6-m diameter mirrors,to be constructed at the LHAASO *** study focused on optimizing the array layout and analyzing the performance of *** observation modes were examined:large zenith angle observations for ultra-high energy events and small zenith angle observations for lower energy *** large zenith angles(60°),simulations indicate that an 8-telescope subarray can achieve an effective area of 3km^(2)with excellent angular *** small zenith angles,we optimized the layout of 4-telescope cells and the full 32-telescope *** energy threshold of the full array is approximately 200 GeV,which is particularly crucial for studying transient phenomena such as gamma-ray bursts(GRBs)and active galactic nuclei(AGNs).This study provides essential guidance for finalizing the LACT layout design and estimating performance under various observational *** also highlights the potential of LACT for conducting deep observations of ultra-high energyγ-ray sources,performing morphological studies of PeVatrons,and advancing time-domainγ-ray astronomy.

关键词： IACT γ-ray LHAASO

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Correction of the Temperature Effect of Muon Counts Observed at the Guangzhou Station

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Research in Astronomy and Astrophysics 2023年第2期23卷 132-139页

作者： Cao-Long Xu Yang Wang Gang Qin Ping-Bing Zuo School of Science Harbin Institute of TechnologyShenzhenShenzhen 518055China Laboratory for Space Weather Storms Institute of Space Science and Applied TechnologyHarbin Institute of TechnologyShenzhenShenzhen 518055China

Muons are the main component of secondary cosmic rays,and the variation in muon intensity indicates the variation in primary cosmic ray ***,before using muons to study the variation in the intensity of cosmic rays,it is necessary to eliminate the atmospheric effects,such as pressure and temperature *** this work,the temperature effect of the muons is corrected in terms of empirical method by using ground *** temperature correction is applied to the muon data observed at the Guangzhou station during the period2010–2021 after a barometric *** is found that the effect of seasonal variations in temperature on muon counts is greatly eliminated in the corrected ***,the muon data are well correlated with the neutron data in comparison,which verifies the reliability of the corrected muon *** results show that the correction of muon data by using ground temperature is an effective method.

关键词： atmospheric effects-Sun activity-(ISM:)cosmic rays

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Conformational Disorder Within the Crystalline Region of Silica-Filled Polydimethylsiloxane:A Solid-State NMR Study

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Chinese Journal of Polymer science 2024年第11期42卷 1780-1792,I0012页

作者： Yu-Qi Xiong Chang-Lin Li Ai Lu Liang-Bin Li Wei Chen National Synchrotron Radiation Laboratory Anhui Provincial Engineering Laboratory of Advanced Functional Polymer FilmCAS Key Laboratory of Soft Matter ChemistryUniversity of Science and Technology of ChinaHefei230026China Department of Accelerator Science and Engineering Physics School of Nuclear Science and TechnologyUniversity of Science and Technology of ChinaHefei230026China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang621900China

The crystallization behavior of silica-filled polydimethylsiloxane(PDMS)was investigated in detail by^(1)H solid-state nuclear magnetic resonance(^(1)H SS-NMR)in combination with synchrotron radiation wide-angle X-ray scattering(WAXS),and temperature-modulated differential scanning calorimetry(TMDSC)*** neat PDMS,no apparent difference is observed for the crystallinity characterized by^(1)H SS-NMR and WAXS at low-temperature ***,upon filler addition,a 15%-35%lower difference in crystallinity is observed measured by^(1)H SS-NMR compared to *** origin of such mismatch was explored through multi-component structural,dynamics,and chain-order analysis of PDMS samples with different filler *** 1D integrated WAXS results of PDMS with different filler fractions at different temperatures show that the packing structure as well as crystal size basically remain unchanged,but as the filler fraction increases from 0 phr to 60 phr,the rigid component’s dynamics order parameter S_(r)obtained by^(1)H SS-NMR decreases from 0.70 to *** filler fraction-dependent crystallinity calculated based on S_(r)was compared with experimental values,revealing a behavior of decreasing order in the crystalline *** with the results of accelerated chain dynamics in crystalline region as reflected by T_(2)values,the molecular origin is attributed to the formation of CONDIS crystals,whose conformational order is lost but the position and orientation orders are *** hypothesis is further supported by the TMDSC results,where,as the filler fraction increases from 0 phr to 60 phr,the melting range widens from 8.77 K to 14.56 K,representing a growth of166%.In addition to previous reports related to the condition for forming CONDIS mesophase,i.e.,temperature,pressure,and stretching,the nano-sized filler could also introduce the local conformational disorder for chain packing.

关键词： Solid state NMR Polymer nanocomposite CONDIS crystal Local chain order PDMS crystallization

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Observation of regular pulse train in a narrow-band optoelectronic oscillator

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Optoelectronics Letters 2024年第2期20卷 94-99页

作者： ZHAO Chunbo TUO Zhuoyue YAO Jiali HE Yuling ZHAI Shenghua MENG Yansong China Academy of Space Technology(Xi’an) Xi’an 710000China National Key Laboratory of Science and Technology on Space Microwave Xi’an 710000China1

We have experimentally observed a new operating state of a regular pulse train in a narrow-band optoelectronic oscillator(OEO) system, where the direct-current(DC) bias of the Mach-Zehnder modulator is set at the maximum value of the transmission transfer function instead of the usual quadrature point. The observed quasi-steady-state pulse train is distinctly periodic, with a period of 10.5 μs and a center frequency of 10 GHz, and resembles a mode-locked OEO in its waveform. The formation of regular pulses here may arise from the dynamic balance of nonlinearity and narrow-band filter effects, with the transient characteristics of the pulses arising mainly from instabilities between the gain and cavity loss. Our results are of great importance for deepening the understanding of the nonlinear dynamical processes in OEO systems.

关键词： optoelectronic pulse modulator

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A deeper and hotter Martian core-mantle differentiation inferred from FeO partitioning

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science Bulletin 2025年第3期70卷 429-436页

作者： Yunguo Li Chunhui Li You Zhou Yun Liu Huaiwei Ni State Key Laboratory of Lithospheric and Environmental Coevolution University of Science and Technology of ChinaHefei 230026China Deep Space Exploration Laboratory/School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Research Centre for Planetary Science College of Earth and Planetary SciencesChengdu University of TechnologyChengdu 610059China State Key Laboratory of Ore Deposit Geochemistry Chinese Academy of SciencesGuiyang 550081China

The core-mantle differentiation process plays a pivotal role in redistributing material on a massive scale,shaping the long-term evolution of rocky *** this process is crucial for gaining insights into the accretion and evolution of planets like ***,the details of Mars’s core-mantle differentiation remain poorly understood due to limited compositional data for its core and *** this study,we aim to constrain the Martian core-mantle differentiation by examining FeO partitioning between core and mantle materials,incorporating improved Martian compositional data from the InSight *** ab initio thermodynamic techniques,we calculated the FeO partition coefficient between liquid iron and silicate *** results align with previous studies while also clarifying the factors affecting partitioning *** on these findings and estimates of oxygen concentration in the core,we infer that Mars’s core and mantle likely differentiated at temperatures above 2440 K and pressures ranging from 14 to 22 *** these estimates are higher than previously reported,they are consistent with observed abundances of moderately siderophile elements and Mars’s accretion models.

关键词： Mars Core-mantle differentiation Volatile Partitioning

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Cathodic corrosion as a facile and universal method for scalable preparation of powdery single atom electrocatalysts

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Nano Research 2024年第6期17卷 4943-4950页

作者： Rui Li Xiayan Yan Meng Liu Qingkai Zhao Jie Du Xinxin Tan Jingwen Ba Rongguang Zeng Wenhua Luo Jingsong Xu Institute of Materials China Academy of Engineering PhysicsJiangyou 621907China Science and Technology on Surface Physics and Chemistry Laboratory Jiangyou 621908China

Top-down strategy has been widely applied for synthesis of metal single atom catalysts(SACs)via converting metal nanoparticles or bulk metals into atomically dispersed ***,we report a simple electrochemical atomic migration strategy for top-down synthesis of SACs via a facile cathodic corrosion process without involving high temperature or harsh *** of metal nanoparticles on cathode are firstly disbanded under high negative voltage,and emitted into the electrolyte in the form of atomic metal anions in Zintl *** escaped atomically dispersed metal species are then oxidized by water molecules and captured by the defects on the pre-added nitrogen doped carbon carriers in the *** cathodic corrosion strategy is confirmed to be suitable for scalable synthesis of kinds of metal SACs(e.g.,Pt,Pd,and Ir)on doped carbon ***,the as-prepared nitrogen doped carbon powder supported Pt SACs exhibit superior catalytic activity toward hydrogen evolution reaction(HER)with a low overpotential of 0.024 V at 10 mA·cm^(−2)and a low Tafel slope of 29.7 mV·dec^(−1)as well as a long-term durability.

关键词： cathodic corrosion top-down strategy powdery single atom catalysts hydrogen evolution reaction scalable synthesis

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Structure feature extraction algorithm for Multi-modal forearm registration 6

Structure feature extraction algorithm for Multi-modal forea...

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6th Conference on Frontiers in Optical Imaging and technology: Applications of Imaging Technologies

作者： You, Sibo Ding, Yan Mo, Bo Zhang, Weizhong Li, Jiaxin Guo, Lingxi Yang, Zhe Beijing Institute of Technology Beijing100081 China Science and Technology on Space Physics Laboratory Beijing100076 China

ISBN: (数字)9781510679757

ISBN: (纸本)9781510679740

While convolutional neural networks have shown promise in medical image registration, their inherent complexity limits their registration speed, particularly for surgical applications. Additionally, traditional feature-based matching methods struggle with multi-modal forearm image registration due to the simplicity of forearm skin textures. To address these issues, we propose a robust forearm feature point extraction method based on the forearm’s structural invariance. We combine this method with thin plate spline interpolation to achieve multi-modal forearm registration. Our approach introduces the Forearm Feature Representation Curve (FFRC) and the Multi-Modal Image Registration Framework (FAM) for aligning forearm images with digital anatomical models. FFRC identifies feature points based on forearm structural characteristics, and FAM employs FFRC for matching point pre-screening before applying an affine transformation. For deformable registration which adds Thin Plate Spline (FAM-TPS) uses the matched points as control points. In our experiments, both FAM and FAM-TPS demonstrate high registration accuracy, with FAM-TPS outperforming conventional feature-based methods. Our framework excels at registering forearm images with varying rotation angles, and we have observed a strong correlation between the feature curve’s peak value and the rotation angle. These results affirm the effectiveness of our approach in achieving precise and resilient registration. © 2024 SPIE.

关键词： Feature extraction

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