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Stepped-up development of accelerator mass spectrometry method for the detection of ^(60)Fe with the HI-13 tandem accelerator

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Nuclear Science and Techniques 2024年第4期35卷 136-143页

作者： yang Zhang sheng-Quan Yan Ming He Qing-Zhang Zhao Wen-Hui Zhang Chao-Xin Kan Jian-Ming Zhou Kang-Ning Li Xiao-Fei Wang Jian-Cheng Liu Zhao-Hua Peng Zhuo Liang Ai-Ling Li Jian Zheng Qi-Wen Fan Yun-Ju Li You-Bao Wang Zhi-Hong Li yang-ping shen Ding Nan Wei Nan Yu-Qiang Zhang Jia-Ying-Hao Li Jun-Wen Tian Jiang-Lin Hou Chang-Xin Guo Zhi-Cheng Zhang Ming-Hao Zhu Yu-Wen Chen Yu-Chen Jiang Tao Tian Jin-Long Ma Yi-Hui Liu Jing-Yu Dong Run-Long Liu Mei-Yue-Nan Ma Yong-Shou Chen Wei-ping Liu Bing Guo China Institute of Atomic Energy P.O.Box 275(10)Beijing 102413China College of Science Southern University of Science and TechnologyShenzhen 518055China School of Physics Xi’an Jiaotong UniversityXi’an 710049China

The Moon provides a unique environment for investigating nearby astrophysical events such as *** samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)*** this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy *** particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the ***,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS *** results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)*** sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.

关键词： Accelerator mass spectrometry Wien filter Isobar separation Supernovae Chang'e-5 lunar samples

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Palladium-Catalyzed Cyclocarbonylation of 2-Halobenzaldehyde and Hydrazines： A Facile Synthesis of 2-Aminoisoindolin-l-ones

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Chinese Journal of Chemistry 2013年第2期31卷 182-186页

作者： Chao Han yang shen ping Lu yanguang Wang Department of Chemistry Zhejiang University Hangzhou Zhejiang 310027 China

An efficient procedure for the synthesis of 2-aminoisoindolin-l-ones via a palladium-catalyzed three-component reaction of 2-halobenzaldehydes, hydrazines and carbon monoxide is reported. This cyclocarbonylation process can be performed smoothly under 1 atmospheric pressure of carbon monoxide to afford 2-aminoisoindolin- 1-ones in moderate to excellent yields.

关键词： cyclocarbonylation 2-aminoisoindolin-l-ones multicomponent reactions heterocycles

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Response functions of a 4π summing gamma detector in β-Oslo method

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Nuclear Science and Techniques 2022年第6期33卷 9-17页

作者： Guo-Chun yang Lei-Ming Hua Fei Lu Jun Su Zhi-Hong Li Shi-Lun Jin yang-ping shen Bing Guo Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China Key Laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China China Institute of Atomic Energy P.O.Box 275(10)Beijing 102413China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

The response functions of a 4π summing BGO detector were established using extensive experimental measurements and GEANT4 simulation. The partial and total efficiencies for all components of the γ-ray interaction with the BGO detector were also measured. These response functions and efficiencies will be used in the β-Oslo method experiments to study the neutron capture cross sections of radioactive heavy ions. The application of the response functions of the BGO detector under simulated continuum γ-rays and source measurement γ-rays proves that the method and response functions are reliable.

关键词： 4πSumming BGO detector γ-Ray spectrum Energy resolutions GEANT4 simulation

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Ordered Bicontinuous Network Structures Regulated by Orientational Interactions in a Rod-Coil Block Copolymer

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Chinese Journal of Polymer Science 2024年第5期42卷 636-642,I0008页

作者： Xiao-Lin Lyu Shi-Chu yang An-Qi Xiao ping-ping Hou Wei Zhang Hong-Bing Pan Zhi-Hao shen Xing-He Fan Qi-Feng Zhou Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou350108China

The rich phase behavior of block copolymers(BCPs)has drawn great attention in recent ***,the double diamond(DD)phase is rarely obtained because of the competition between the minimization of interfacial energy and packing ***,a rod-coil BCP containing mesogen-jacketed liquid crystalline polymer is designed to acquire ordered bicontinuous network *** reduction of internal energy originating from the orientational interaction among the rod blocks can compensate for the free energy penalty of packing frustration to stabilize the DD *** resulting BCP can also experience lamellae-to-DD and double gyroid-to-lamellae transitions by changing the annealing *** results make the rod-coil BCP an excellent candidate for the self-assembly of ordered network structures,demonstrating great potential in nanopatterning and metamaterials.

关键词： Block copolymer Rod-coil Ordered bicontinuous phase Double diamond Double gyroid

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Characteristics of bioaerosols under high-ozone periods,haze episodes,dust storms,and normal days in Xi'an,China

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Particuology 2024年第7期90卷 140-148页

作者： Yiming yang Liu yang Xiaoyan Hu Zhenxing shen Department of Environmental Science and Engineering Xi’an Jiaotong UniversityXi’an710049China Key Lab of Aerosol Chemistry&Physics SKLLQGInstitute of Earth EnvironmentChinese Academy of SciencesXi’an710049China

The characteristics of bioaerosols and their effects on human beings'health have become a major public concern in the recent *** study compared the characteristics of bioaerosols under different types of pollution(high-ozone[HO]episodes,haze episodes,and dust storms[DSs]),with those of bioaerosols on normal days(NDs)in Xi'an,*** concentrations,diurnal variations,and size distribution of bacteria,fungi,and total airborne microbes(TAMs)were *** results showed that the bacterial and fungal concentrations were the highest during DSs and on NDs,reaching 425.2 and 956.9 colony-forming units/m^(3),*** concentration of TAMs was the highest during HO episodes,reaching 10.7×10^(6)cells/m^(3),which was significantly higher than that during the other *** maximum concentrations of bacteria and fungi during HO episodes were observed in the morning,while they appeared separately in the morning and evening during haze *** and TAMs during DSs reached peak concentrations in the morning and evening,which is opposite to the particulate matter(PM)distribution *** NDs,temperature and relative humidity had significant effects on *** size distributions of airborne bacteria exhibited bimodal patterns,whereas unimodal distributions were observed for *** mainly attached in fine particles(<2.1μm)with proportions of 67.4%and 60.5%during haze episodes and DSs,respectively,which means that fungi were easily penetrated into the human respiratory *** evaluation of influence factors revealed that PM_(2.5) and PM10 had negative effects on fungal concentration during DSs,and ozone concentration and temperature were inversely correlated with fungal concentration during HO *** results provide valuable reference data for elucidating the formation and evolution of bioaerosols under different types of pollution.

关键词： Bacteria Fungi Total airborne microbe Different air pollution types Influence factors

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Transient Characteristics and Accommodative Current Limiting Strategy for Bidirectional Interlinking Converters in Hybrid AC/DC Microgrids

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1575-1588页

作者： Xia shen Zhikang Shuai Wen Huang Chao shen yang shen Z.John shen College of Electrical and Information Engineering Hunan UniversityChangsha 410082China Department of Electrical and Computer Engineering Illinois Institute of TechnologyChicagoIL 60616 USA

Bidirectional interlinking converter(BIC)is the core equipment in a hybrid AC/DC microgrid connected between AC and DC ***,the variety of control modes and flexible bidirectional power flow complicate the influence of AC faults on BIC itself and on DC sub-grid,which potentially threaten both converter safety and system *** study first investigates AC fault influence on the BIC and DC bus voltage under different BIC control modes and different pre-fault operation states,by developing a mathematical model and equivalent sequence ***,based on the analysis results,a general accommodative current limiting strategy is proposed for BIC without limitations to specific mode or operation *** amplitude is predicted and constrained according to the critical requirements to protect the BIC and relieving the AC fault influence on the DC bus *** with conventional methods,potential current limit failure and distortions under asymmetric faults can also be ***,experiments verify feasibility of the proposed method.

关键词： Bidirectional interlinking converter current limiting fault characteristic hybrid AC/DC microgrid variation/oscillation of DC bus voltage

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Aggregation-regulated bioreduction process of graphene oxide by Shewanella bacteria

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Chinese Journal of Chemical Engineering 2024年第5期69卷 56-62页

作者： Kaixin Han Yibo Zeng Yinghua Lu ping Zeng Liang shen Department of Chemical and Biochemical Engineering College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China Chinese Research Academy of Environmental Sciences Beijing 100012China

The bioreduction of graphene oxide(GO)using environmentally functional bacteria such as Shewanella represents a green approach to produce reduced graphene oxide(rGO).This process differs from the chemical reduction that involves instantaneous molecular *** bioreduction,the contact of bacterial cells and GO is considered the rate-limiting *** reveal how the bacteria-GO integration regulates rGO production,the comparative experiments of GO and three Shewanella strains were carried ***-transform infrared spectroscopy,X-ray photoelectron spectroscopy,Raman spectroscopy,and atomic force microscopy were used to characterize the reduction degree and the aggregation *** results showed that a spontaneous aggregation of GO and Shewanella into the condensed entity occurred within 36 h.A positive linear correlation was established,linking three indexes of the aggregation potential,the bacterial reduction ability,and the reduction degree(ID/IG)comprehensively.

关键词： Graphene oxide Reduced graphene oxide Bioreduction Aggregation Shewanella

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Study on γ-ray source from the resonant reaction ^19F(p,αγ)^16O at Ep=340 keV

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Chinese Physics B 2020年第7期29卷 269-274页

作者： Fu-Long Liu Wan-Sha yang Ji-Hong Wei Di Wu yang-Fan He Yu-Chen Li Tian-Li Ma yang-ping shen Qi-Wen Fan Chuang-Ye He Bing Guo Nai-Yan Wang Key Laboratory of Radiation Beam Technology and Materials Modification of the Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China China Institute of Atomic Energy Beijing 102413China Beijing Radiation Center Beijing 100875China

High energyγ-ray can be used in many fields,such as nuclear resonant fluorescence,nuclear medicine *** of the methods to generate high-energyγ-ray is nuclear resonant *** 19F(p,αγ)16O reaction was used to generate 6.13-MeVγ-ray in this *** angular distribution of 6.13-MeVγ-ray was measured by six LaBr3 *** thick-target yield curve of 6.13-MeVγ-ray had been *** maximum yield was determined to be(1.85±0.01)×10^-8γ/proton,which was measured by HPGe detector and LaBr3 *** absolute efficiency of all the detectors was calibrated using 60Co and 27Al(p,γ)^28Si reaction at Ep=992 *** cross section and total resonant width of the reaction were determined to be 95.1±1.0 mb(1 b=10^-24 cm^2)andΓCM=2.21±0.22 keV,respectively.

关键词： high-energyγ-ray source thick-target yield resonant reaction cross section

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Multi-faceted spatio-temporal network for weather-aware air traffic flow prediction in multi-airport system

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Chinese Journal of Aeronautics 2024年第7期37卷 301-316页

作者： Kaiquan CAI Shuo TANG shengsheng QIAN Zhiqi shen yang yang School of Electronic and Information Engineering Beihang UniversityBeijing 100191China State Key Laboratory of CNS/ATM Beijing100191China Institute of Automation Chinese Academy of SciencesBeijing 100190China Research Institute for Frontier Science Beihang UniversityBeijing 100191China

As one of the core modules for air traffic flow management,Air Traffic Flow Prediction(ATFP)in the Multi-Airport System(MAS)is a prerequisite for demand and capacity balance in the complex meteorological *** to the challenge of implicit interaction mechanism among traffic flow,airspace capacity and weather impact,the Weather-aware ATFP(Wa-ATFP)is still a nontrivial *** this paper,a novel Multi-faceted Spatio-Temporal Graph Convolutional Network(MSTGCN)is proposed to address the Wa-ATFP within the complex operations of ***,a spatio-temporal graph is constructed with three different nodes,including airport,route,and fix to describe the topology structure of ***,a weather-aware multi-faceted fusion module is proposed to integrate the feature of air traffic flow and the auxiliary features of capacity and weather,which can effectively address the complex impact of severe weather,e.g.,***,to capture the latent connections of nodes,an adaptive graph connection constructor is *** experimental results with the real-world operational dataset in Guangdong-Hong Kong-Macao Greater Bay Area,China,validate that the proposed approach outperforms the state-of-the-art machine-learning and deep-learning based baseline approaches in performance.

关键词： Air traffic control Graph neural network Multi-faceted information Air traffic flow prediction Multi-airport system

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High-performance flexible semiconductor fibres for multi-scenario communication applications

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Science China Materials 2024年第7期67卷 2363-2364页

作者： Qinghui Lin yang Li Guozhen shen School of Information Science and Engineering University of JinanJinan 250022China School of Microelectronics Shandong UniversityJinan 250101China School of Integrated Circuits and Electronics Beijing Institute of Technology Beijing 100081China

With the advances in the field of flexible fibre technology in recent years,a variety of flexible fibres with different preparation processes have emerged[1,2].However,most of the flexible fibres in the past have structural breaks,making them unsuitable for long-term use as wearable fabrics[3,4].Glass semiconductors are widely used in thermally stretched fibres due to their advantages such as controllable fluidity,but they suffer from electronic defects compared with crystalline semi conductors in electronic semiconductors such as silicon(Si)and germanium(Ge)[5].Obviously,the semiconductor component in flexible optic fibres is a key component in regulating their mechanical and electrical properties[6].

关键词： wear fibres fibre

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