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Significant changes in the physicochemical properties of BC-containing particles during the cold season in Beijing

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Journal of Environmental Sciences 2025年第5期151卷 667-676页

作者： Shuya Hu Linghan Zeng Gang zhao shiyi chen Chunsheng zhao Weilun zhao Min Hu State Key Joint Laboratory of Environmental Simulation and Pollution Control International Joint Research Center for Atmospheric Research(IJRC)College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China Department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing University of Information Science and TechnologyNanjing 210044China

The ambient air quality has improved significantly under strict emission controls in Beijing,China over the last *** carbon(BC),as a short-lived climate forcer in ambient aerosols,profoundly impacts the air quality and *** studies have demonstrated a decline in the mass concentration of *** this study,we characterized the chemical compositions and size distributions of BC-containing particles during the cold season of 2022 in Beijing using state-of-the-art instruments capable of exclusively measuring BCcontaining *** optical properties of BC-containing particles were further calculated based on the Mie ***,we compared the properties of BC-containing particles in 2022 with the results of previous *** results showed that the diameters of BC cores became larger while the coating thickness of BC-containing particles became thinner in *** the coating materials,the mass fraction of nitrate increased obviously,and even replaced organic matter as the dominant component during the peak of the pollution *** in chemical compositions and size distributions resulted in lower mass absorption cross-sections(MAC)of BC-containing particles from 10.5±1.1 m^(2)/g in 2016 to 7.3±0.8 m^(2)/g in 2022,reduced by 30.5%.Our results demonstrate the synergistic benefits of air pollution control in improving air quality and mitigating climate ***,the MAC of BC adopted in climate models should vary with the changing air pollution *** study emphasizes that it is imperative to conduct long-term observations of BC-containing particles to better estimate BC’s climate effects.

关键词： Black carbon Chemical composition Size distribution Light absorption ability

Persistent luminescence encoding for rapid and accurate oral-derived bacteria identification

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Chinese Chemical Letters 2025年第1期36卷 459-463页

作者： Chaohui zheng Jing Xi shiyi Long Tianpei He Rui zhao Xinyuan Luo Na chen Quan Yuan The Second Affiliated Hospital of Fujian Medical University Quanzhou 362000China Renmin Hospital of Wuhan University College of Chemistry and Molecular SciencesInstitute of Molecular MedicineSchool of MicroelectronicsWuhan UniversityWuhan 430072China Molecular Science and Biomedicine Laboratory(MBL) State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China

The dysbiosis of oral microbiota contributes to diseases such as periodontitis and certain cancers by triggering the host inflammatory *** methods for the immediate and sensitive identification of oral microorganism is crucial for the rapid diagnosis and early interventions of associated *** methods for microbial detection primarily include the plate culturing,polymerase chain reaction and enzyme-linked immunosorbent assay,which are either time-consuming or ***,we reported a persistent luminescence-encoded multiple-channel optical sensing array and achieved the rapid and accurate identification of oral-derived *** results demonstrate that electrostatic attractions and hydrophobic-hydrophobic interactions dominate the binding of the persistent luminescent nanoprobes to oral microorganisms and the microbial identification process can be finished within 30 ***,a total of 7 oral-derived microorganisms demonstrate their own response patterns and were differentiated by linear discriminant analysis(LDA)with the accuracy up to 100%both in the solution and artificial saliva ***,the persistent luminescence encoded array sensor could also discern the microorganism mixtures with the accuracy up to 100%.The proposed persistent luminescence encoding sensor arrays in this work might offer new ideas for rapid and accurate oralderived microorganism detection,and provide new ways for disease diagnosis associated with microbial metabolism.

关键词： Oral microorganisms Persistent luminescent nanoprobes Optical sensing array Fingerprint physicochemical properties Linear discriminant analysis

Derivatives of local times and Hausdorff dimension of inverse images of space-time anisotropic Gaussian random fields

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Acta Mathematica Sinica,English Series 2025年

作者： zhenlong chen Peng Xu School of Statistics and Mathematics Zhejiang Gongshang University

Let X={X（t）, t∈RN}be a centered space-time anisotropic Gaussian random field with values in Rd. Under some general conditions, the existence, joint continuity and H¨older conditions of higher-order derivative of local times of X are studied. Moreover, we obtain the uniform Hausdorff dimension of the inverse images of X. The existing results of Gaussian random fields are extended to space-time anisotropic Gaussian random fields with approximate independent components.

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Utilizing BP neural networks to accurately reconstruct the tritium depth profile in materials for BIXS

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Nuclear Science and Techniques 2025年第1期36卷 103-114页

作者： chen zhao Wei Jin Yan Shi Chang-An chen Yi-Ying zhao Institute of Materials China Academy of Engineering PhysicsJiangyou 621908China

β-ray-induced X-ray spectroscopy(BIXS)is a promising method for tritium detection in solid materials because of its unique advantages,such as large detection depth,nondestructive testing capabilities,and low requirements for sample ***,high-accuracy reconstruction of the tritium depth profile remains a significant challenge for this *** this study,a novel reconstruction method based on a backpropagation(BP)neural network algorithm that demonstrates high accuracy,broad applicability,and robust noise resistance is *** average reconstruction error calculated using the BP network(8.0%)was much lower than that obtained using traditional numerical methods(26.5%).In addition,the BP method can accurately reconstruct BIX spectra of samples with an unknown range of tritium and exhibits wide applicability to spectra with various tritium ***,the BP network demonstrates superior accuracy and stability compared to numerical methods when reconstructing the spectra,with a relative uncertainty ranging from 0 to 10%.This study highlights the advantages of BP networks in accurately reconstructing the tritium depth profile from BIXS and promotes their further application in tritium detection.

关键词： β-ray-induced X-ray spectroscopy Tritium detection BP network Ridge regression Reconstruction problem

Precise gradient separation of nanoparticles using reduced graphene oxide-polyoxomolybdate membranes

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Science China Chemistry 2025年第1期68卷 209-216页

作者： Yixin Yang Wanlei zhao Ruoxuan zheng Hongqiang Li Wei chen Yu-Fei Song State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China Quzhou Institute for Innovation in Resource Chemical Engineering Quzhou 324000China

The purification and size sieving of nanoparticles(NPs)represents a significant scientific ***,the rGO-polyoxometalates(POMs=PMo_(12),Mo_(132)and Mo_(368))membranes were fabricated successfully via a simple and scalable POMsassisted in-situ photoreduction *** the mass ratio of rGO to PMo_(12)was 1:30,the resultant rGO-PMo_(12)membranes with highly ordered and uniform nanochannels of 1.0 nm can be obtained,which showed an accurate carbon quantum dots(CQDs)separation with a cut-off size approximately 1.0 *** increase of the size of the interlayered POMs from PMo_(12)(1.0 nm),{Mo132}(2.9 nm)to{Mo_(368)}(3.8 nm),the resultant rGO-PMo_(12),rGO-Mo_(132)and rGO-Mo_(368)exhibited precise gradient separation of CQDs and Au nanoparticles by size exclusion *** results pave a promising way to construct new twodimensional(2D)membranes for highly efficient size-selective separation.

关键词： reduced graphene oxide polyoxometalates membranes gradient separation nanoparticles

Effect of graphene addition on activation and kinetic properties of La-Mg-Ni-based hydrogen storage alloys

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Journal of Iron and Steel Research International 2025年第1期32卷 227-238页

作者： Dian-chen Feng Chun-ling zheng Zhi-yuan zhao Dong-sheng Zhou Hui-ping Ren Yang-huan Zhang School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou014010Inner MongoliaChina Collaborative Innovation Center of Integrated Exploitation of Bayan Obo Multi-Metal Resources Inner Mongolia University of Science and TechnologyBaotou014010Inner MongoliaChina Department of Functional Material Research China Iron and Steel Research Institute GroupBeijing100081China

The La_(1.7)Pr_(0.3)Mg_(16)Ni hydrogen storage alloy was prepared by medium-frequency induction melting,and then the composite hydrogen storage alloy powder of La_(1.7)Pr_(0.3)Mg_(16)Ni+x wt.%(x=0,2,4,and 6)graphene was prepared by ball milling for 10 *** effect of the addition of graphene on the activation and hydrogen de/absorption properties of La_(1.7)Pr_(0.3)Mg_(16)Ni alloy was *** result demonstrated that these composite alloys were composed of La_(2)Mg_(17),La_(2)Ni_(3),and Mg_(2)Ni *** saturated hydrogen absorption,it was composed of LaH_(3),Mg_(2)NiH_(4),and MgH_(2)phases,while during the dehydrogenation process,it was composed of LaH_(3),Mg,and Mg_(2)Ni *** addition of graphene can help get a more homogeneous granule after ball milling and accelerate the first activation of dehydrogenation/hydrogen *** hydrogen release activation energy of the alloys first decreases and then increases as the graphene content increases from x=0 wt.%to x=6 wt.%.The minimum activation energy of the composite hydrogen storage alloy is 51.22 kJ mol^(-1) when x=4 wt.%.

关键词： La-Mg-Ni alloy Graphene Mechanical ball milling Activation property Dynamic performance

Unraveling the reaction mechanism of high reversible capacity CuP_(2)/C anode with native oxidation PO_(x) component for sodium-ion batteries

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Chinese Chemical Letters 2025年第1期36卷 574-578页

作者： Huixin chen chen zhao Hongjun Yue Guiming Zhong Xiang Han Liang Yin Ding chen State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China CAS key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China College of Materials Science and Engineering Co-Innovation Center of Efficient Processing and Utilization of Forest ResourcesNanjing Forestry UniversityNanjing 210037China Laboratory of Advanced Spectro-electrochemistry and Li-ion Batteries Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Institute of Physics Chinese Academy of SciencesBeijing 100190China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi institutesChinese Academy of SciencesXiamen 361021China

Phosphorus-based anode is a promising anode for sodium-ion batteries(SIBs)due to its high specific capacity,however,suffers from poor electronic conductivity and unfavorable electrochemical *** metals such as copper(Cu)into phosphorus has been demonstrated to not only improve the electronic conductivity but also accommodate the volume change during cycling,yet the underline sodiation mechanism is not ***,take a copper phosphide and reduced graphene oxide(CuP_(2)/C)composite as an example,which delivers a high reversible capacity of>900 mAh/***,it is revealed that the native oxidation PO_(x)components of the CuP_(2)/C composite show higher electrochemical reversibility than the bulk Cu P_(2),based on a quantitative analysis of high-resolution solid-state^(31)P NMR,ex-situ XPS and synchrotron X-ray diffraction characterization *** sodiation products Na_(3)PO_(4) and Na_(4)P_(2)O_(7) derived from PO_(x) could react with Na-P alloys and regenerate to PO_(x) during charge process,which probably accounts for the high reversible capacity of the Cu P_(2)/C *** findings also illustrate that the phosphorus transforms into nanocrystalline Na_(3)P and Na_(x)P alloys,which laterally shows crystallization-amorphization evolution process during cycling.

关键词： CuP_(2)/C composite POx component Reaction mechanism Solid-state NMR Sodium-ion batteries

Carbon emissions in China’s steel industry from a life cycle perspective:Carbon footprint insights

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Journal of Environmental Sciences 2025年第2期148卷 650-664页

作者： Xiaocong Song Shuai Du chenning Deng Peng Shen Minghui Xie Ci zhao chen chen Xiaoyu Liu State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Beijing Key Laboratory of Water Resources&Environmental Engineering China University of Geosciences(Beijing)Beijing 100083China Chinese Research Academy of Environmental Sciences Environmental Technology&Engineering Co.Ltd. Beijing 100012China

China is the most important steel producer in the world,and its steel industry is one of themost carbon-intensive industries in ***,research on carbon emissions from the steel industry is crucial for China to achieve carbon neutrality and meet its sustainable global development *** constructed a carbon dioxide(CO_(2))emission model for China’s iron and steel industry froma life cycle perspective,conducted an empirical analysis based on data from2019,and calculated the CO_(2)emissions of the industry throughout its life *** emission reduction factors were identified using sensitivity *** results demonstrated that the CO_(2)emission intensity of the steel industry was 2.33 ton CO_(2)/ton,and the production and manufacturing stages were the main sources of CO_(2)emissions,accounting for 89.84%of the total steel life-cycle ***,fossil fuel combustion had the highest sensitivity to steel CO_(2)emissions,with a sensitivity coefficient of 0.68,reducing the amount of fossil fuel combustion by 20%and carbon emissions by 13.60%.The sensitivities of power structure optimization and scrap consumption were similar,while that of the transportation structure adjustment was the lowest,with a sensitivity coefficient of less than *** the current strategic goals of peak carbon and carbon neutrality,it is in the best interest of the Chinese government to actively promote energy-saving and low-carbon technologies,increase the ratio of scrap steel to steelmaking,and build a new power system.

关键词： Iron and steel industry Life cycle Carbon dioxide(CO_(2))emissions Carbon footprint China

In-situ Si particle-reinforced joints of hypereutectic Al−60Si alloys by ultrasonic-assisted soldering

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Transactions of Nonferrous Metals Society of China 2025年第1期35卷 77-90页

作者： Yuan-xing LI Xiang-bo zheng Chao-zheng zhao Zong-tao ZHU Yu-jie BAI Hui chen Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

To improve the wettability of hypereutectic Al−60Si alloy and enhance the mechanical properties of the joints,Al−60Si alloy was joined by ultrasonic soldering with Sn-9Zn solder,and a sound joint with in-situ Si particle reinforcement was *** oxide film of Al−60Si alloy at the interface was identified by transmission electron microscopy(TEM)analysis as amorphous Al_(2)O_(3).The oxide of Si particles in the base metal was also *** oxide film of Al−60Si alloy was observed to be removed by ultrasonic vibration instead of holding *** particle-reinforced joints(35.7 vol.%)were obtained by increasing the ultrasonication *** maximum shear strength peaked at 99.5 MPa for soldering at 330℃with an ultrasonic vibration time of 50 s.A model of forming of Si particles reinforced joint under the ultrasound was proposed,and ultrasonic vibration was considered to promote the dissolution of Al and migration of Si particles.

关键词： hypereutectic Al−60Si alloy ultrasonic-assisted soldering Si particle reinforcement Sn−9Zn solder