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Chinese Optics Letters 2019年第4期17卷 84-88页

作者： Lida zhu Yi wang Yi Yuan Hongxian zhou Yuqian zhao Zhenhe ma School of Electrical Engineering Yanshan University School of Control Engineering Northeastern University at Qinhuangdao Experiment Education Center Northeastern University at Qinhuangdao

We demonstrated a method for measurement of central corneal thickness(CCT) with a sub-micrometer sensitivity using a spectral domain optical coherence tomography system without needing a super broad bandwidth light source. By combining the frequency and phase components of Fourier transform, the method is capable of measurement of a large dynamic range with a high sensitivity. Absolute phases are retrieved by comparing the correlations between the detected and simulated interference fringes. The phase unwrapping ability of the present method was quantitatively tested by measuring the displacement of a piezo linear stage. The human CCTs of six volunteers were measured to verify its clinical application. It provides a potential tool for clinical diagnosis and research applications in ophthalmology.

关键词： measurement of central coherence tomography applications in ophthalmology

Ex utero intrapartum therapy in infants with congenital diaphragmatic hernia:a propensity score matching analysis

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World Journal of Pediatric Surgery 2022年第4期5卷 267-274页

作者： Yunlong zhao Ying wang Chao Liu Yulin Jiang Yandong wei Hua Meng Shan Jian Xiting zhu Lijian Pei Xiaochen Bai Feng Feng Yan Lv Xiya zhou Qingwei Qi Jingna Li Lishuang ma Peking Union Medical College Graduate School BeijingChina Department of Neonatal Surgery Children’s Hospital of Capital Institute of PediatricsCapital Institute of PediatricsBeijingChina Department of Obstetrics Peking Union Medical College HospitalBeijingChina Department of Ultrasound Peking Union Medical College HospitalBeijingChina Department of Pediatrics Peking Union Medical College HospitalBeijingChina Department of Biostatistics and Statistical Programming Everest Clinical Research CorporationBeijingChina Department of Anesthesiology Peking Union Medical College HospitalBeijingChina Department of Pediatrics Beijing Obstetrics and Gynecology HospitalCapital Medical UniversityBeijingChina Department of Radiology Peking Union Medical College HospitalBeijingChina

Objective Previous studies have shown that ex utero intrapartum therapy(EXIT)is safe and feasible for newborns with congenital diaphragmatic hernia(CDH).This study reports our experience with EXIT in fetuses with CDH in an attempt to explore the efficacy of EXIT on the survival rate of this *** A retrospective analysis of the clinical data of 116 children with CDH was *** children were assigned to EXIT and non-EXIT *** score matching(PSM)toward clinical data was performed,and the clinical characteristics and outcomes were *** survival at discharge as the main outcome,logistic regression analysis was carried out to explore the efficacy of EXIT on *** During the study period,30 of 116 children received *** PSM,the survival rates of the EXIT group and the non-EXIT group were 82.76%(24/29)and 48.28%(14/29),respectively(p=0.006).EXIT(OR=0.083,95%CI=0.013to 0.525,p=0.008),liver herniation(OR=16.955,95%CI=2.342 to 122.767,p=0.005),and gestational age at diagnosis(OR=0.662,95%CI=0.497 to 0.881,p=0.005)were independent mortality-related risk factors of all children with ***-nine of 116 children underwent *** PSM,the postoperative survival rates of the EXIT group and non-EXIT group were 84.6%(22/26)and 76.9%(20/26),respectively(p=0.754).Liver herniation(OR=10.451,95%CI=1.641 to 66.544,p=0.013)and gestational age at diagnosis(OR=0.736,95%CI=0.577 to 0.938,p=0.013)were independent mortality-related risk factors of children after *** EXIT can be performed safely for selected prenatally diagnosed CDH neonates with potentially better survival and does not cause more maternal complications compared with traditional cesarean section.

关键词： hernia diagnosis congenital

New insights into multiple provenances evolution of the Jurassic from heavy minerals characteristics in southern Junggar Basin, NW China

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Petroleum Exploration and Development 2019年第1期46卷 67-81页

作者： zhou Tianqi WU Chaodong YUAN Bo SHI Zhongkui wang Jialin zhu Wen zhou Yanxi JIANG Xi zhao Jinyong wang Jun ma Jian Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education School of Earth and Space Sciences Peking University Institute of Oil and Gas Peking University Geophysics Department in Exploration and Development Institution of Xinjiang Oilfield Company Institute of Remote Sensing and Geographical Information System School of Earth and Space Sciences Peking University Petroleum Exploration and Production Research Institute Sinopec Department of Xinjiang Exploration Project management Sinopec Shengli Oilfield Company

The method of random forest was used to classify the heavy mineral assemblages of 2 418 Jurassic samples in the southern Junggar Basin, and determine the distribution of the heavy mineral assemblages from the same provenance systems. Based on the analysis of heavy minerals assemblages, ZTR index, sedimentary characteristics, U-Pb zircon ages, whole-rock geochemical and paleocurrent direction analysis, the study reveals that five important provenances were providing sediments to the southern Junggar Basin in the Jurassic period: The North Tianshan(NTS), Central Tianshan(CTS), Bogda Mountains, Zhayier Mountains and Kalamaili Mountains. During the Early Jurassic, NTS-CTS, Kalamaili Mountains and Zhayier Mountains are primary provenances, Bogda Mountains started to uplift and supply clastic materials in the Middle Jurassic. There are three sedimentary area in the Jurassic of southern Junggar Basin: the western part, the central part and the eastern part. In the western part, the clastic materials of the Early Jurassic was mainly from NTS blocks and Zhayier Mountains, and the sediments were dominantly derived from the Zhayier Mountains during the Middle–Late Jurassic. In the central part, the main provenance of the Early Jurassic switched from NTS to CTS. In the Xishanyao Formation, the main source went back to NTS again. The NTS was the primary provenance during the sedimentary periods of Toutunhe Formation and Qigu Formation. In the eastern part, the contribution of CTS and Kalamaili Mountains were considered as major provenances in the Early Jurassic-Xishanyao Formation, small proportion of sediments were from NTS. The Bogda mountains uplifted and started to provide sediments to the Junggar Basin in the sedimentary period of Xishanyao Formation, and became the major source during the Toutunhe Formation period, with small amount of sediments from CTS. The provenance from CTS was hindered during the sedimentary period of Qigu Formation owing to the uplifting of the Bogd

关键词： southern Junggar Basin Jurassic source to sink system provenance heavy minerals assemblages random forest

Recent advances in RNA structurome

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Science China(Life Sciences) 2022年第7期65卷 1285-1324页

作者： Bingbing Xu Yanda zhu Changchang Cao Hao Chen Qiongli Jin Guangnan Li Junfeng ma Siwy Ling Yang Jieyu zhao Jianghui zhu Yiliang Ding Xianyang fang Yongfeng Jin Chun Kit Kwok Aiming Ren Yue Wan Zhiye wang Yuanchao Xue Huakun Zhang Qiangfeng Cliff Zhang Yu zhou MOE Laboratory of Biosystems Homeostasis&Protection Innovation Center for Cell Signaling NetworkCollege of Life SciencesZhejiang UniversityHangzhou 310058China Key Laboratory of RNA Biology Institute of BiophysicsChinese Academy of SciencesBeijing 100101China Life Sciences Institute Zhejiang UniversityHangzhou 310058China State Key Laboratory of Plant Physiology and Biochemistry College of Life SciencesZhejiang UniversityHangzhou 310058China State Key Laboratory of Virology College of Life SciencesWuhan UniversityWuhan 430072China Beijing Advanced Innovation Center for Structural Biology School of Life SciencesTsinghua UniversityBeijing 100084China Stem Cell and Regenerative Biology Genome Institute of SingaporeA*STARSingaporeSingapore Department of Chemistry and State Key Laboratory of Marine PollutionCity University of Hong KongHong KongChina MOE Key Laboratory of Bioinformatics Beijing Advanced Innovation Center for Structural Biology and Frontier Research Center for Biological StructureCenter for Synthetic and Systems BiologySchool of Life SciencesTsinghua UniversityBeijing 100084China Tsinghua-Peking Center for Life Sciences Beijing 100084China Department of Cell and Developmental Biology John Innes CentreNorwich Research ParkNorwich NR47UHUnited Kingdom Shenzhen Research Institute of City University of Hong Kong Shenzhen 518057China University of Chinese Academy of Sciences Beijing 100101China Key Laboratory of Molecular Epigenetics of the Ministry of Education Northeast Normal UniversityChangchun 130024China

RNA structures are essential to support RNA functions and regulation in various biological processes. Recently, a range of novel technologies have been developed to decode genome-wide RNA structures and novel modes of functionality across a wide range of species. In this review, we summarize key strategies for probing the RNA structurome and discuss the pros and cons of representative technologies. In particular, these new technologies have been applied to dissect the structural landscape of the SARS-CoV-2 RNA genome. We also summarize the functionalities of RNA structures discovered in different regulatory layers-including RNA processing, transport, localization, and mRNA translation-across viruses, bacteria, animals, and plants. We review many versatile RNA structural elements in the context of different physiological and pathological processes(e.g., cell differentiation, stress response, and viral replication). Finally, we discuss future prospects for RNA structural studies to map the RNA structurome at higher resolution and at the single-molecule and single-cell level, and to decipher novel modes of RNA structures and functions for innovative applications.

关键词： RNA structurome high-throughput techniques genome-wide 3D structure RNA secondary structure SARS-CoV-2 decoding function

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magnetic resonance imaging of the zone of calcified cartilage in the knee joint using 3-dimensional ultrashort echo time cones sequences

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Chinese Medical Journal 2019年第5期132卷 562-568页

作者： Jin Liu Yang wei Ya-Jun ma Yan-Chun zhu Quan zhou Ying-Hua zhao Department of Radiology Third Affiliated Hospital of Southern Medical University (Academy of Orthopedics Guangdong Province) Guangzhou Guangdong 510630 China Guangdong Provincial Key Laboratory of Medical Image Processing School of Biomedical Engineering Southern Medical University Guangzhou Guangdong 510515 China Department of Radiology University of CaliforniaSan DiegoSan DiegoCAUSA

Background: The zone of calcified cartilage (ZCC) plays an important role in the pathogenesis of osteoarthritis (OA) but has never been imaged in vivo with magnetic resonance (MR) imaging techniques. We investigated the feasibility of direct imaging of the ZCC in both cadaveric whole knee specimens and in vivo healthy knees using a 3-dimensional ultrashort echo time cones (3D UTE-Cones) sequence on a clinical 3T scanner. Methods: In all, 12 cadaveric knee joints and 10 in vivo healthy were collected. At a 3T MR scanner with an 8-channel knee coil, a fat-saturated 3D dual-echo UTE-Cones sequence was used to image the ZCC, following with a short rectangular pulse excitation and 3D spiral sampling with conical view ordering. The regions of interests (ROIs) were delineated by a blinded observer. Singlecomponent T2* and T2 values were calculated from fat-saturated 3D dual-echo UTE-Cones and a Carr-Purcell-Meiboom-Gill (T2 CPMG) data using a semi-automated maTLAB code. Results: The single-exponential fitting curve of ZCC was accurately obtained with R2 of 0.989. For keen joint samples, the ZCC has a short T2* ranging from 0.62 to 2.55 ms, with the mean ±standard deviation (SD) of 1.49 ±0.66 ms, and with 95% confidence intervals (CI) of 1.20-1.78 ms. For volunteers, the short T2* ranges from 0.93 to 3.52ms, with the mean±SD of 2.09±0.56 ms, and the 95% CI is 1.43 to 2.74ms in ZCC. Conclusions: The high-resolution 3D UTE-Cones sequence might be used to directly image ZCC in the human knee joint on a clinical 3T scanner with a scan time of more than 10 min. Using this non-invasive technique, the T2* relaxation time of the ZCC can be further detected.

关键词： Ultrashort echo time T2* relaxation time Zone of calcified cartilage Articular cartilage

Development of New InDel marker to Detect Genotypes of Rf-1a Conferring Fertility Restoration of BT-Type Cytoplasmic male Sterility in Rice

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Rice science 2014年第1期21卷 13-19页

作者： CHEN Tao ZHANG Ya-dong zhu Zhen zhao Ling zhao Qing-yong zhou Li-hui YAO Shu YU Xin wang Cai-lin Institute of Food Crops Jiangsu Academy of Agricultural Sciences / Jiangsu High Quality Rice R & D Center / Nanjing Branch of China National Center for Rice Improvement

Restorer line breeding is an important approach to enhance the heterosis and improve the yields of japonica hybrid rice. To improve the selection efficiency of restorer lines for BT-type cytoplasmic male sterility （CMS） in japonica rice, a functional marker InDeI-Rf-la based on the difference of nucleotide sequence in Rf-la locus between BT-type CMS lines and restorer lines was developed to detect the genotypes of different rice materials. Conventional indica rice varieties, restorer and maintainer lines without 574 bp deletion could restore the fertility for BT-type CMS in japonica rice. By contrast, most conventional japonica rice varieties except Aichi 106 and Yijing 12, with genotype of rf-larf-la showed the 574 bp deletion maintained sterility for BT-type CMS lines. To further verify the effect of genotyping detection in Rf-la locus, this marker was also used to amplify the genomic DNA in different japonica rice restorer lines, CMS lines, hybrids and F2 segregation population, and three genotypes in Rf-la locus could be distinguished distinctly. Therefore, the marker InDeI-Rf-la could be widely used for genetic id^ntifio.~tinn ~nd m^rkp.r-~.~.~i^fp.d .~.*** （ma.~ in hr~=dinn i^nnnir~ r^fnr~=r lin==~

关键词： BT-type cytoplasmic male sterility fertility restoration Rf-la gene InDel marker japonica rice

Dietary Patterns Associated Metabolic Syndrome in Chinese Adults

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Biomedical and Environmental Sciences 2015年第5期28卷 370-373页

作者： HE Deng Hua YANG Min ZHANG Rong Hua ma Xiao Guang HUANG Li Chun HUANG En Shan GU wei zhu Yi Bo zhao Dong zhu Xu Hui DING Gang Qiang zhou Biao Department of Nutrition and Food Hygiene Medical School of Ningbo University Department of Nutrition and Food Hygiene Zhejiang University School of Public Health Zhejiang Provincial Center for Disease Control and Prevention

Dietary pattern has been revealed to be associated with metabolic syndrome. However, the association was not well documented in Chinese due to the complexity of Chinese foods. We mainly assessed the dietary patterns and examined their effects on metabolic syndrome among Chinese adults. Four dietary patterns including ＇Refined Grains ＆ Vegetables＂ Pattern, ＇Dairy ＆ Eggs＇ Pattern, ＇Organ Meat ＆ Poultry＇ Pattern, and ＇Coarse Grains ＆ Beans＇ Pattern were extracted. ＇Dairy ＆ Eggs＇ Pattern was associated with a decreased odds of metabolic syndrome in women, and ＇Coarse Grains ＆ Beans＇ Pattern was associated with a decreased odds of hypertension in men. These results provided a scientific basis for future research and dietarv euideline Perfection.

关键词： Dietary Patterns Associated Metabolic Syndrome in Chinese Adults FBG HDL

Recent Progress on Two-Dimensional materials

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物理化学学报 2022年

作者： Cheng Chang wei Chen Ye Chen Yonghua Chen Yu Chen Feng Ding Chunhai fan Hongjin fan Zhanxi fan Cheng Gong Yongji Gong Qiyuan He Xun Hong Sheng Hu weida Hu wei Huang Yuan Huang wei Ji Dehui Li Lain-Jong Li Qiang Li Li Lin Chongyi Ling Minghua Liu Nan Liu zhuang Liu Kian Ping Loh Jianmin ma Feng Miao Hailin Peng Mingfei Shao Li Song Shao Su Shuo Sun Chaoliang Tan Zhiyong Tang Dingsheng wang Huan wang Jinlan wang Xin wang Xinran wang Andrew T. S. Wee Zhongming wei Yuen Wu Zhongshuai Wu Jie Xiong Qihua Xiong weigao Xu Peng Yin Haibo Zeng Zhiyuan Zeng Tianyou Zhai Han Zhang Hui Zhang Qichun Zhang Tierui Zhang Xiang Zhang Lidong zhao Meiting zhao weijie zhao Yunxuan zhao Kaige zhou Xing zhou Yu zhou Hongwei zhu Hua Zhang Zhongfan Liu Department of Electrical and Computer Engineering and Quantum Technology Center， University of maryland， College Park School of materials Science and Engineering， Beihang University Department of materials Science and Engineering， City University of Hong Kong Center of Advanced Nanocatalysis (CAN)， Hefei National Laboratory for Physical Sciences at the Microscale， Department of Applied Chemistry， University of Science and Technology of China College of Chemistry and Chemical Engineering， State Key Laboratory of Physical Chemistry of Solid Surfaces， Collaborative Innovation Center of Chemistry for Energy materials (iChEM)， Xiamen University State Key Laboratory of Infrared Physics， Shanghai Institute of Technical Physics， Chinese Academy of Sciences Advanced Research Institute of Multidisciplinary Science， Beijing Institute of Technology Beijing Key Laboratory of Optoelectronic Functional materials & Micro-Nano Devices， Department of Physics， Renmin University of China School of Optical and Electronic Information， Wuhan National Laboratory for Optoelectronics， Huazhong University of Science and Technology Department of Mechanical Engineering， The University of Hong Kong Institute of Science and Technology Austria School of Physics， Southeast University Department of materials Science and Engineering， National University of Singapore CAS Key Laboratory of Colloid， Interface and Chemical Thermodynamics， Institute of Chemistry， Chinese Academy of Sciences College of Chemistry， Beijing Normal University Institute of Functional Nano & Soft materials (FUNSOM)， Jiangsu Key Laboratory for Carbon-based Functional materials and Devices， Soochow University School of materials and Energy， University of Electronic Science and Technology of China School of Physics， Nanjing University Center for Nanochemistry (CNC)， Beijing National Laboratory for Molecular Sciences， College of Chemistry and Molecular Engineering， Beijing Graphene Institute (BGI)， Peking University State Key Laboratory of Chemical Resource Engineering， Beijing

Research on two-dimensional (2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics， electronic engineering， materials science， and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene， 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular， we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review， we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief background introduction， we first discuss the major synthetic methods for 2D materials， including the mechanical exfoliation， liquid exfoliation， vapor phase deposition， and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials (PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that， the promising applications of 2D materials in electronics， optoelectronics， catalysis， energy storage， solar cells， biomedicine， sensors， environments， etc. are described sequentially. Thereafter， we present the theoretic calculations and simulations of 2D materials. Finally， after concluding the current progress， we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.

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Metatranscriptome of human lung microbial communities in a cohort of mechanically ventilated COVID-19 Omicron patients

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Signal Transduction and Targeted Therapy 2023年第12期8卷 5919-5930页

作者： Lin wang Jia-Bao Cao Bin-Bin Xia Yue-Juan Li Xuan Zhang Guo-Xin Mo Rui-Juan wang Si-Qi Guo Yu-Qing Zhang Kun Xiao Guang-Fa zhu Peng-Fei Liu Li-Cheng Song Xi-Hui ma Ping-Chao Xiang Jiang wang Yu-Hong Liu Fei Xie Xu-Dong Zhang Xiang-Xin Li Wan-Lu Sun Yan Cao Kai-Fei wang Wen-Hui Zhang wei-Chao zhao Peng Yan Ji-Chao Chen Yu-wei Yang Zhong-Kuo Yu Jing-Si Tang Li Xiao Jie-Min zhou Li-Xin Xie Jun wang College of Pulmonary&Critical Care Medicine 8th Medical Center of Chinese PLA General HospitalBeijing 100091China CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Faculty of Biological Science and Technology Baotou Teacher’s CollegeBaotou 014030China Department of Respiratory Medicine PLA Strategic Support Force Medical CenterBeijing 100101China Department of Respiratory and Critical Care Medicine Beijing Anzhen HospitalCapital Medical UniversityBeijing Institute of HeartLung and Blood Vessel DiseasesBeijing 100029China Respiratory Research Institute Department of Pulmonary&Critical Care MedicineBeijing Key Laboratory of OTIRthe 8th Medical Center of Chinese PLA General HospitalBeijing 100091China Shougang hospital of Peking University Beijing 100144China Department of Respiratory Medicine Beijing Changping HospitalBeijing 102200China Department of Respiratory and Critical Care Medicine Beijing Institute of Respiratory Medicine and Beijing Chao-Yang HospitalCapital Medical UniversityBeijing 100020China Pulmonary research institute Senior Department of Respiratory and Critical Care Medicinethe 8th medical center of Chinese PLA general hospitalBeijing 100091China College of Pulmonary&Critical Care Medicine Chinese PLA General HospitalBeijing 100853China China Aerospace Science&Industry Corporation 731 hospital Beijing 100074China Department of Respiratory and Critical Care Medicine Aerospace Center HospitalBeijing 100049China Vision Medicals Center for Infectious Diseases Guangzhou 510700China

The Omicron variant of the severe acute respiratory syndrome coronavirus 2(SARS‑CoV‑2)infected a substantial proportion of Chinese population,and understanding the factors underlying the severity of the disease and fatality is valuable for future prevention and clinical *** recruited 64 patients with invasive ventilation for COVID-19 and performed metatranscriptomic sequencing to profile host transcriptomic profiles,plus viral,bacterial,and fungal content,as well as virulence factors and examined their relationships to 28-day mortality were *** addition,the bronchoalveolar lavage fluid(BALF)samples from invasive ventilated hospital/community-acquired pneumonia patients(HAP/CAP)sampled in 2019 were included for *** analysis revealed that all Omicron strains belong to BA.5 and BF.7 sub-lineages,with no difference in 28-day mortality between *** to HAP/CAP cohort,invasive ventilated COVID-19 patients have distinct host transcriptomic and microbial signatures in the lower respiratory tract;and in the COVID-19 non-survivors,we found significantly lower gene expressions in pathways related viral processes and positive regulation of protein localization to plasma membrane,higher abundance of opportunistic pathogens including bacterial Alloprevotella,Caulobacter,Escherichia-Shigella,Ralstonia and fungal Aspergillus sydowii and Penicillium *** analysis further revealed significant associations between host immune responses and microbial compositions,besides synergy within viral,bacterial,and fungal *** study presents the relationships of lower respiratory tract microbiome and transcriptome in invasive ventilated COVID-19 patients,providing the basis for future clinical treatment and reduction of fatality.

关键词： patients mortality prevention

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