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Local environment regulation of transition metal dichalcogenide-based single-atom catalysts

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Rare Metals 2024年第9期43卷 4019-4037页

作者： Ming-Hui Li Jing Li Xiao-Yu Zheng Yao Zhou Advanced Research institute of Multidisciplinary Science andSchool of Chemistry and Chemical Engineering Beijing Institute of Technology Laser Micro/Nano Fabrication Laboratory School of Mechanical Engineering Beijing Institute of Technology

Single-atom catalysts have risen significant attention in the realm of green electrocatalytic energy conversion to address energy and environmental sustainability challenges. Transition metal dichalcogenide（TMD）-based single-atom catalysts are considered highly effective in electrocatalysis due to the TMDs' notable specific surface area, tunable elemental species and efficient utilization of single atoms. In order to enhance electrocatalytic performance, it is imperative to elaborately engineer the local environment surrounding the active sites of single atoms within TMDs. In this review, we initially explore the effects of synthesis methods on single-atom active sites and the influence of loading of single atoms on catalytic performance for TMDs. The modulation strategies of the local environment surrounding single-atom sites in TMDs are elaborated, including substitution engineering,surface adsorption, vacancies, spatial confinement and dual-atom site strategies. For each modulation strategy, the effects of diverse local environments on various electrocatalytic applications are presented, such as the oxygen evolution reaction, oxygen reduction reaction, nitrogen reduction reaction, CO2reduction reaction and CO oxidation. Ultimately, this study presents a comprehensive overview of the challenges encountered and the potential directions for the advancement of single-atom catalysts based on TMDs in the realm of electrocatalysis.

关键词： Electrocatalysis

Cyclicity of the Lower Buntsandstein in the eastern part of the Central European Basin:implications for Early Triassic palaeogeography and for geochronological calibration

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Journal of Palaeogeography 2024年第2期13卷 252-292页

作者： Anna Becker Polish Geological institute-National Research institute 4 Rakowiecka str.00-975 WarsawPoland

Lower Buntsandstein small—scale cycles recognized in the Central European Basin(CEB) are readily used for astrochronological calibration of the Early Triassic time scales,although they are not well studied *** borehole sections from the eastern part of the CEB,forming a south-north transect perpendicular to the basin axis,were studied in terms to better understand the depositional history of the Lower Buntsandstein developed as the Baltic Formation in the studied Polish part of the *** sedimentary facies were recognized,based on lithological and sedimentological investigations of 655.7 m of drill cores from the Otyń IG 1,Gorzów Wielkopolski IG 1 and Kamień Pomorski IG 1 *** facies can be grouped according to a lithological criterion into facies of predominantly siliciclastic lithology(including 9facies types) and facies of predominantly carbonate lithology(including 2 facies types).Facies analysis allowed to distinguish 8 facies associations of:1) alluvial fan,2) playa,3) sandy-muddy coastal plain,4)embayment and distal delta,5) lagoon,6) sand bars or shoals,7) ooidal shoals or bars,and 8) ***-upward(DC) and shallowing-upward(SC) sedimentary cycles were recognized in parts of the Baltic Formation,with DCs dominating in the southernmost located Otyń IG 1,and SCs dominating in Gorz ow Wielkopolski IG 1,located in the axial part of the *** cycles are very *** statistical significance of the sedimentary cycles is relatively low according to Markov-chain analysis conducted with the phpSedistat software of Stanova et al.(2009).Analysis of small—scale cycles performed on well logs of investigated boreholes and additional boreholes in the vicinity of Otyń IG 1,implementing the earlier study of Becker(2005),showed that the correlation of well-log cycles(GR cycles) and sedimentary cycles is not *** cycles can be roughly correlated with lithological carbonate—siliciclastic cycles(c-s cycles),refle

关键词： Triassic Lower Buntsandstein Cyclicity Central European Basin

Repeat-pass space-surface bistatic SAR tomography:accurate imaging and first experiment

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Science China(Information Sciences) 2024年第09期67卷 245-262页

作者： Zhiyang CHEN Yuanhao LI Cheng HU Shenglei WANG Xinpeng CHEN Mihai DATCU Andrea Virgilio MONTI-GUARNIERI Radar Technology Research institute School of Information and Electronics Beijing Institute of Technology Beijing Key Laboratory of Embedded Real-Time Information Processing Technology Beijing Institute of Technology Advanced Technology Research institute Beijing Institute of Technology CEOSpace Tech University Politehnica of Bucharest Dipartimento di Elettronica Informazione e Bioingegneria Politecnico di Milano

Space-surface bistatic synthetic aperture radar(SS-BiSAR) offers an additional observation angle for monostatic spaceborne SAR, making it a promising technology for high-accuracy deformation retrieval technology in local regions. Repeat-pass SS-BiSAR tomography can accurately estimate the surfaces of buildings and steep areas, effectively removing terrain phases during deformation retrieving. However, inaccuracies in the orbital ephemeris can lead to image geometry distortion, reducing image pair coherence,introducing interferometric phase errors, and consequently deteriorating tomographic precision. This paper precisely models the image geometry distortion and interferometric phase error caused by repeat-pass ephemeris error. We propose an ephemeris correction method based on the chirp-Z transform to address these issues. Furthermore, we introduce an accurate tomography model to improve 3D reconstruction *** first SS-BiSAR tomography experiment, conducted using the Chinese Lutan-1 satellite, demonstrates that the correlation coefficient is improved by 0.16 after ephemeris error correction. Moreover, the density and precision of the tomographic point cloud are improved by 13.7% and 12.1%, respectively.

关键词： space-surface SAR tomography orbit error image distortion Lutan-1

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The Epidemiological Characteristics of Mpox Cases-China,2023

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China CDC weekly 2024年第26期6卷 619-623页

作者： Ruiqi Ren Chao Li Wenqing Bai Yali Wang Dan Li Fan Ding Niu Yan Qi Wang Nijuan Xiang Lianmei Jin Lei Zhou Wenling Wang Fan Lyu Peilong Li Dapeng Zhang Yan Li Quanyi Wang Qun Li Guoqing Shi National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases Chinese Center for Disease Control and PreventionBeijingChina Chinese Center for Disease Control and Prevention BeijingChina National institute for Viral Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina National Center for aids/STD Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina Guangdong Provincial Center for Disease Control and Prevention Guangzhou CityGuangdong ProvinceChina Beijing Municipal Center for Disease Prevention and Control BeijingChina

Summary What is already known about this topic?Since May 2022,a global outbreak of mpox has emerged in more than 100 non-endemic *** of December 2023,over 90,000 cases had been *** outbreak has predominantly affected men who have sex with men(MSM),with sexual contact identified as the principal mode of *** is added by this report?Since June 2023,China has faced an occurrence of mpox,predominantly affecting the MSM *** 90%of those affected reported engaging in homosexual behavior within 21 days prior to symptom onset,a trend that aligns with the global outbreak *** prompt identification of cases,diligent tracing of close contacts,and the implementation of appropriate management strategies have successfully mitigated the spread of mpox virus in *** are the implications for public health practice?We propose that mpox is transmitted locally within *** from our experiences in controlling the virus spread,it is crucial to investigate and formulate effective surveillance and educational ***,we must encourage high-risk populations to promptly seek medical care upon the onset of symptoms.

关键词： prompt Drawing spread

Pulsed THz radiation under ultrafast optical discharge of vacuum photodiode

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Frontiers of Optoelectronics 2024年第2期17卷 99-112页

作者： Aleksandr Ushakov Kseniia Mamaeva Leonid Seleznev Georgy Rizaev Vladimir Bukin Timophey Dolmatov Pavel Chizhov Vladimir Bagdasarov Sergey Garnov Prokhorov General Physics institute of the Russian Academy of Sciences Moscow 119991Russia Physical institute Russian Academy of SciencesMoscow 119991Russia Moscow institute of Physics and Technology Dolgoprudny 141700Russia Russian institute for Scientific and Technical Information Moscow 125190Russia

In this paper,we first present an experimental demonstration of terahertz radiation pulse generation with energy up to 5 pJ under the electron emission during ultrafast optical discharge of a vacuum *** use a femtosecond optical excitation of metallic copper photocathode for the generation of ultrashort electron bunch and up to 45 kV/cm external electric field for the photo-emitted electron *** of terahertz pulses energy as a function of emitted charge density,incidence angle of optical radiation and applied electric field have been *** and polarization characteristics of generated terahertz pulses have also been *** proposed semi-analytical model and simulations in COMSOL Multiphysics prove the experimental data and allow for the optimization of experimental conditions aimed at flexible control of radiation parameters.

关键词： Electron emission Vacuum photodiode Ultrafast excitation Terahertz

The differential effects of integrase strand transfer inhibitors and efavirenz on neuropsychiatric conditions and brain imaging in hiv-positive men who have sex with men

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生物安全与健康(英文) 2024年第04期06卷 216-224页

作者： He Yihui Zhang Yang Zhen Jiaxin Sun Guangqiang Li Zhen Yang Bo Yang Bin Chang Keyi Chen Xue Zhang Yulin Guo Caiping Wang Wen Wu Ping Zhang Tong Wang Lei Postgraduate Union Training Base of Jinzhou Medical University PLA Rocket Force Characteristic Medical Center Beijing China Department of Neurology PLA Rocket Force Characteristic Medical Center Beijing China Center for Infectious Disease Beijing Youan Hospital Capital Medical University Beijing China Beijing Key Laboratory for hiv/aids Research Beijing China Beijing institute for Sexually Transmitted Disease Control Beijing China Beijing Key Laboratory of Mental Disorders National Clinical Research Center for Mental Disorders and National Center for Mental Disorders Beijing Anding Hospital Capital Medical University Beijing China Advanced Innovation Center for Human Brain Protection Capital Medical University Beijing China The Second Hospital of Beijing Beijing China Department of Respiratory and Critical Care Medicine Beijing Youan Hospital Capital Medical University Beijing China National institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Peking University Beijing China Key Discipline for Neuroscience of the Ministry of Education Department of Neurobiology School of Basic Medical Sciences Peking University Health Science Center Beijing China

Integrase strand transfer inhibitors (INSTIs) have emerged as the first-line choice for treating human immunodeficiency virus (hiv) infection due to their superior efficacy and safety. However, the impact of INSTIs on the development of neuropsychiatric conditions in people living with hiv (PLWH) is not fully understood due to limited data. In this study, we conducted a cross-sectional examination of PLWH receiving antiretroviral therapy, with a specific focus on hiv-positive men who have sex with men (MSM) on INSTI-based regimens (n = 61) and efavirenz (EFV)-based regimens (n = 28). Participants underwent comprehensive neuropsychiatric evaluations and multimodal magnetic resonance imaging (MRI) scans, including T1-weighted images and resting-state functional MRI. Compared to the EFV group, the INSTI group exhibited primarily reduced gray matter volume (GMV) in the right superior parietal gyrus, higher regional homogeneity (ReHo) in the left post-central gyrus, lower ReHo in the right orbital part of the inferior frontal gyrus, and increased voxel-wise functional connectivity for the seed region in the left inferior temporal gyrus with clusters in the right cuneus. Furthermore, the analysis revealed a main effect of antiretroviral drugs on GMV changes, but no main effect of neuropsychiatric disorders or their interaction. The repeated analysis of participants who did not switch regimens confirmed the GMV changes in the INSTI group, validating the initial findings. Our study demonstrated gray matter atrophy and functional brain changes in PLWH on INSTI-based regimens compared to those on EFV-based regimens. These neuroimaging results provide valuable insights into the characteristics of brain network modifications in PLWH receiving INSTI-based regimens.

关键词： Human immunodeficiency virus (hiv) Multimodal magnetic resonance imaging (MRI) Integrase strand transfer inhibitors (INSTIs) Efavirenz (EFV)

Phase-field simulations of the effect of temperature and interface for zirconiumδ-hydrides

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Chinese Physics B 2024年第4期33卷 701-710页

作者：陈子航盛杰刘瑜施小明黄厚兵许可王越超武帅孙博刘海风宋海峰 School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Advanced Research institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100088China Department of Physics University of Science and Technology BeijingBeijing 100083China

Hydride precipitation in zirconium cladding materials can damage their integrity and *** temperature and material defects have a significant effect on the dynamic growth of *** this study,we have developed a phasefield model based on the assumption of elastic behaviour within a specific temperature range(613 K-653 K).This model allows us to study the influence of temperature and interfacial effects on the morphology,stress,and average growth rate of zirconium *** results suggest that changes in temperature and interfacial energy influence the length-to-thickness ratio and average growth rate of the hydride *** ultimate determinant of hydride orientation is the loss of interfacial coherency,primarily induced by interfacial dislocation defects and quantifiable by the mismatch degree *** escalation in interfacial coherency loss leads to a transition of hydride growth from horizontal to vertical,accompanied by the onset of redirection ***,redirection occurs at a critical mismatch level,denoted as qc,and remains unaffected by variations in temperature and interfacial ***,this redirection leads to an increase in the maximum stress,which may influence the direction of hydride crack *** research highlights the importance of interfacial coherency and provides valuable insights into the morphology and growth kinetics of hydrides in zirconium alloys.

关键词： zirconium hydride phase-field method temperature effect mismatch degree

Predict the evolution of mechanical property of Al-Li alloys in a marine environment

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Defence Technology（防务技术） 2024年第1期31卷 557-566页

作者： Wei Li Lin Xiang Guang Wu Hongli Si Jinyan Chen Yiming Jin Yan Su Jianquan Tao Chunyang Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100036China Chongqing Innovation Center Beijing Institute of TechnologyChongqing400044China First Research institute of the Ministry of Public Security for PR China Beijing100036China Southwest Technology and Engineering Research institute Chongqing400039China

The ocean is one of the essential fields of national defense in the future,and more and more attention is paid to the lightweight research of Marine equipment and *** study it is to develop a Machine learning(ML)-based prediction method to study the evolution of the mechanical properties of Al-Li alloys in the marine *** obtained the mechanical properties of Al-Li alloy samples under uniaxial tensile deformation at different exposure times through Marine exposure *** obtained the strain evolution by digital image correlation(DIC).The strain field images are voxelized using 2D-Convolutional Neural Networks(CNN)autoencoders as input data for Long Short-Term Memory(LSTM)neural ***,the output data of LSTM neural networks combined with corrosion features were input into the Back Propagation(BP)neural network to predict the mechanical properties of Al-Li *** main conclusions are as follows:*** variation law of mechanical properties of2297-T8 in the Marine atmosphere is *** the increase in outdoor exposure test time,the tensile elastic model of 2297-T8 changes slowly,within 10%,and the tensile yield stress changes significantly,with a maximum attenuation of 23.6%.*** prediction model can predict the strain evolution and mechanical response simultaneously with an error of less than 5%.*** study shows that a CNN/LSTM system based on machine learning can be built to capture the corrosion characteristics of Marine exposure *** results show that the relationship between corrosion characteristics and mechanical response can be predicted without considering the microstructure evolution of metal materials.

关键词： Marine environment Al-Li alloy Machine learning Corrosion

Extending microwave-frequency electric-field detection through single transmission peak method

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Chinese Physics B 2024年第5期33卷 417-423页

作者：刘青陈进湛王赫张杰阮伟民伍国柱郑顺元罗景庭宋振飞 College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China Shenzhen institute for Technology Innovation National Institute of MetrologyShenzhen 518107China Center for Advanced Measurement Science National Institute of MetrologyBeijing 100029China

The strength of microwave(MW)electric field can be observed with high precision by using the standard electromagnetically induced transparency and Aulter–Towns(EIT-AT)technique,when its frequency is resonant or nearly-resonant with the Rydberg transition *** the detuning of MW field increases,one of the transmission peaks(single peak)is easier to measure due to its increased *** can be found that the central symmetry point of the two transmission peaks f_(1/2)is only related to the detuning of MW field△_(MW)and central symmetry point f_(0)of resonant MW field,satisfying the relation f_(1/2)=△_(MW)/2+f_(0).Thus,we demonstrate a single transmission peak method that the MW E-field can be determined by interval between the position of single peak and f_(1/2).We use this method to measure continuous frequencies in a band from-200 MHz to 200 MHz of the MW *** experimental results and theoretical analysis are presented to describe the effectiveness of this *** 50 MHz<△_(MW)<200 MHz,this method solves the problem that the AT splitting cannot be measured by using the standard EIT-AT techniques or multiple atomic-level Rydberg atom schemes.

关键词： microwave electric field Rydberg atom electromagnetically induced transparency(EIT) Aulter-Towns splitting