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Einstein Probe discovery of EP240408a: A peculiar X-ray transient with an intermediate timescale

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 222-240页

作者： Wenda zhang Weimin Yuan Zhixing Ling Yong Chen Nanda Rea Arne Rau Zhiming Cai Huaqing Cheng Francesco Coti Zelati Lixin Dai Jingwei Hu Shumei Jia Chichuan Jin Dongyue Li Paul O’Brien Rongfeng Shen Xinwen Shu Shengli Sun Xiaojin Sun Xiaofeng wang Lei yang Bing zhang Chen zhang Shuang-Nan zhang Yonghe zhang Jie An David Buckley Alexis Coleiro Bertrand Cordier Liming Dou Rob Eyles-Ferris Zhou Fan Hua Feng Shaoyu Fu Johan P.U.Fynbo Lluis Galbany Saurabh W.Jha Shuaiqing Jiang Albert Kong Erik Kuulkers Weihua Lei Wenxiong Li Bifang Liu Mingjun Liu Xing Liu Yuan Liu Zhu Liu Chandreyee Maitra Alessio Marino Itumeleng monageng Kirpal Nandra Jeremy Sanders Roberto Soria Lian Tao junfeng wang Song wang Tinggui wang Zhongxiang wang Qingwen Wu Xuefeng Wu Dong Xu yanjun Xu Suijian Xue Yongquan Xue Zijian zhang Zipei Zhu Hu Zou Congying Bao Fansheng Chen Houlei Chen Tianxiang Chen Wei Chen Yehai Chen Yifan Chen Chenzhou Cui Weiwei Cui yanfeng Dai Dongwei Fan Ju Guan Dawei Han Dongjie Hou Haibo Hu Maohai Huang Jia Huo Zhenqing Jia Bowen Jiang Ge Jin Chengkui Li junfei Li Longhui Li Maoshun Li Wei Li Zhengda Li Tianying Lian Congzhan Liu Heyang Liu Huaqiu Liu Fangjun Lu Laidan Luo Jia Ma Xuan Mao Haiwu Pan Xin Pan Liming Song Hui Sun Yunyin Tan Qingjun tang Yihan Tao Hao wang Juan wang Lei wang Wenxin wang Yilong wang Yusa wang Qinyu Wu Haitao Xu Jingjing Xu Xinpeng Xu Yunfei Xu Zhao Xu Changbin Xue Yulong Xue Ailiang yan Haonan yang Xiongtao yang yanji yang Juan zhang mo zhang Wenjie zhang Zhen zhang Zhen zhang Ziliang zhang Donghua Zhao Haisheng Zhao Xiaofan Zhao Zijian Zhao Hongyan Zhou Yilin Zhou Yuxuan Zhu Zhencai Zhu National Astronomical Observatories Chinese Academy of Sciences School of Astronomy and Space Sciences University of Chinese Academy of Sciences key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Institute of Space Sciences (ICE) CSIC Institut d’Estudis Espacials de Catalunya (IEEC) Max Planck Institute for Extraterrestrial Physics Innovation Academy for Microsatellites Chinese Academy of Sciences Department of Physics University of Hong Kong School of Physics and Astronomy University of Leicester School of Physics and Astronomy Sun Yat-sen University Department of Physics Anhui Normal University Shanghai Institute of Technical Physics Chinese Academy of Sciences Physics Department Tsinghua University Nevada Center for Astrophysics University of Nevada Las Vegas Department of Physics and Astronomy University of Nevada Las Vegas South African Astronomical Observatory Department of Astronomy University of Cape Town Department of Physics University of the Free State Université Paris Cité CNRS Astroparticule et Cosmologie Université Paris Cité CEA Paris-Saclay IRFU/DAp-AIM Department of Astronomy Guangzhou University Cosmic Dawn Center (DAWN) Niels Bohr Institute University of Copenhagen Department of Physics and Astronomy Rutgers the State University of New Jersey Institute for Cosmic Ray Research The University of Tokyo ESA/ESTEC Department of Astronomy School of Physics Huazhong University of Science and Technology INAF-Osservatorio Astrofisico di Torino Sydney Institute for Astronomy School of Physics The University of Sydney Department of Astronomy Xiamen University Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University Department of Astronomy University of Science and Technology School of Astronomy and Space Sciences University of Science and Technology of China Institute of Deep Space Sciences Deep Space Exploration Laboratory Department of Astronomy School of Physics and Astronomy Yunnan University Shanghai Astronomical Observatory Chi

We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe （EP） and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength *** new transient was first detected with Wide-field X-ray Telescope （WXT） on board EP on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for *** flare reached a peak flux of 3.9×10-9erg cm-2s-1in 0.5-4 ke V,～300 times brighter than the underlying X-ray emission detected throughout the *** and more precise follow-up observations by EP/FXT,Swift and NICER confirmed the finding of this new *** X-ray spectrum is non-thermal in 0.5-10 ke V,with a power-law photon index varying *** X-ray light curve shows a plateau lasting for ～4 d,followed by a steep decay till becoming undetectable ～10 d after the initial *** on its temporal property and constraints from previous EP observations,an unusual timescale in the range of 7-23 d is found for EP240408a,which is intermediate between the commonly found fast and long-term *** counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these *** demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical *** nature of EP240408a thus remains an *** suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of～10 *** detection and follow-ups of more of such objects are essential for revealing their origin.

关键词： X-ray transients ${\bm~{Einstein~~Probe}}$

Photo-induced Alignment Behavior of Azobenzene-containing Polymer Films with Different Cross-linking Degree

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Chinese Journal of Chemical Physics 2008年第5期21卷 493-499页

作者： Jing Shena Jin-tang Huang yan-hua Luoa Qi-jin zhang ke-yi wang CAS key Laboratory of Soft Matter Chemistry Department of Polymer Science and Engineering Key Laboratory of Optoelectronic Science and Technology Anhui Province University of Science and Technology of China Hefei 230025 China Department of Precision Machinery and Precision Instrumentation University of Science and Tech- nology of China Hefei 230025 China

Three series of amorphous copolymers containing azobenzene groups with various substituents and certain amounts of crosslinkable acrylic groups were prepared. The cross-linked polymer films were obtained by thermal polymerization of the acrylic groups in the copolymers, during which, by controlling the time of cross-linking reaction, the films can be made with different cross-linking degree （from 0 to 32%, which was monitored by FT-IR spectra measurement）. Photo-induced alignment process of the films was performed under irradiation with linearly polarized light at 442 nm, and the effect of cross-linking degree on the photo-induced alignment rate was investigated. The dynamics of the photo-induced alignment was analyzed with biexponential curve fitting. The photo-induced alignment rate and the maximum transmittance of the films decreased because of the cross-linking. Furthermore, for the cross-linked samples, it was found that their saturated value of transmittances keep constant after repeated ＂writing＂ and ＂erasing＂ cycles. The findings reveal that the cross-linking of the film can effectively restrain the phototactic mass transport of azopolymer during irradiation by polarized light. The relationship between the cross-linking degree and the photo-induced alignment behavior of azopolymer is discussed in detail.

关键词： Azo polymer Cross-linking Photo-induced alignment Mass transport

Dynamic micelles with detachable PEGylation at tumoral extracellular pH for enhanced chemotherapy

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Asian Journal of Pharmaceutical Sciences 2020年第6期15卷 728-738页

作者： Guoqing yan Panpan zhang jun wang Xin wang Rupei tang Engineering Research Centerfor Biomedical Materials School of Life ScienceAnhui UniversityHefei 230601China

Although surface PEGylation of nanomedicines can decrease serum protein adsorption in vivo,it also blocks uptake by tumor *** dilemma could be overcome by employing detachably PEGylated strategy at tumoral extracellular microenvironment to achieve improved cellular uptake while prolonged circulation ***,the amphiphilic graft copolymers with p H-sensitive ortho ester-linked m PEG in side chains and polyurethanes in backbone,can self-assemble into the free and doxorubicin(DOX)-loaded *** p H-sensitive micelles could undergo several characteristics as follows:(i)PEGylated shells for stability in sodium dodecyl sulfonate(SDS)solution;(ii)De PEGylation via degradation of ortho ester linkages at tumoral extracellular pH(6.5)for gradually dynamic size changes and effective release of DOX;and(iii)enhanced cellular uptake and cytotoxicity via positive ***,the dynamic micelles with detachable PEGylation could quickly penetrate the centers of SH-SY5 Y multicellular spheroids(MCs)and strongly inhibit tumor growth in vitro and in vivo,and might be considered as promising and effective drug carriers in tumor therapy.

关键词： Micelles Ortho ester PEGylation Size transition Antitumor

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Theoretical understanding of the stability of single-atom catalysts

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National Science Review 2018年第5期5卷 638-641页

作者： Jin-Cheng Liu yan tang yang-Gang wang Tao zhang jun Li Department of Chemistry and key Laboratory of Organic Optoelectronics & molecular Engineering of Ministry of Education Tsinghua University Department of Chemistry Southern University of Science and Technology Dalian Institute of Chemical Physics Chinese Academy of Sciences

As a new frontier, the rapid development of single-atom catalysts (SACs) in heterogeneous catalysis has attracted extensive attention since the concept of singleatom catalysis was first coined in 2011[1,2]. Supported metal single atoms usually possess unique chemical and physical properties and have a special local chemical environment that is dis-

关键词： Theoretical understanding of the stability of single-atom catalysts Pt

Space-frequency-polarization-division multiplexed wireless communication system using anisotropic space-time-coding digital metasurface

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National Science Review 2022年第11期9卷 149-160页

作者： jun Chen ke Xiangyu Chen Wankai tang Ming Zheng Chen Lei zhang Li wang jun yan Dai Jin yang jun Wei zhang Lijie Wu Qiang Cheng Shi Jin Tie jun Cui State key Laboratory of Millimeter Waves Southeast University Institute of Electromagnetic Space Southeast University Frontiers Science Center for mobile Information Communication and Security Southeast University National mobile Communications Research Laboratory Southeast University Southeast University Wuxi Campus

In the past few years, wireless communications based on digital coding metasurfaces have gained research interest owing to their simplified architectures and low cost. However, in most of the metasurface-based wireless systems, a single-polarization scenario is used, limiting the channel capacities. To solve the problem, multiplexing methods have been adopted, but the system complexity is inevitably increased. Here,a space-frequency-polarization-division multiplexed wireless communication system is proposed using an anisotropic space-time-coding digital metasurface. By separately designing time-varying control voltage sequences for differently oriented varactor diodes integrated on the metasurface, we achieve frequency-polarization-division multiplexed modulations. By further introducing different time-delay gradients to the control voltage sequences in two polarization directions, we successfully obtain space-frequency-polarization-division multiplexed modulations to realize a wireless communication system with a new architecture. The new communication system is designed with compact dual-polarized meta-elements, and can improve channel capacity and space utilization. Experimental results demonstrate the high-performance and real-time transmission capability of the proposed communication system,confirming its potential application in multiple-user collaborative wireless communications.

关键词： polarization-division multiplexing frequency-division multiplexing space-division multiplexing space-time coding wireless communication

Screen p53 mutations in hepatocellular carcinoma by FASAY:A novel splicing mutation

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2007年第2期8卷 81-87页

作者： WU Xiao-mo FU Jing-geng GE wang-zhong ZHU Jiang-yan wang jun-yong zhang Wei QIAN Wei HUO ke-ke Institute of Genetics School of Life Sciences Fudan University Shanghai 200433 China

Objective： To establish a routine procedure for the detection of p53 mutations in hepatocellular carcinoma （HCC） surgical resections using the FASAY （functional analysis of separated alleles of p53 on yeast） procedure. Methods： p53 status was analyzed by FASAY and cDNA sequencing in 50 cases of HCC. After the extraction of RNA from the frozen tumor and corresponding normal tissues, reverse transcription RT-PCR was carried out using these samples. The assay can detect mutations of p53 mRNA between codons 67 and 347 by the DNA-binding activity of the protein and reveal them as red colonies. Results： Of the 50 specimens, 29 （58%） were positive （mutan0 by FASAY. Sequencing analysis confirmed that all 29 FASAY positive tumors harbored mutations, and that no mutations were detectable in any FASAY negative tumors. In 29 p53 mutations, 22 mutations were point missense mutation, 5 were deletions and 2 were splicing mutations. A novel splice mutation on splice donor of intron 6 was reported, which could produce two different mRNAs, respectively using the nearest upstream and downstream recessive splice donor sites. Conclusion： FASAY is a sensitive method for detecting the various types of p53 mutations in HCC, suggesting that the yeast functional assay for the detection of p53 mutations may be essential for elucidating their clinical significance.

关键词： Heoatocellular carcinoma (HCC) p53 mutation FASAY Splicing mutation

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Correlation between iron deposition and Alzheimer's disease In vivo preliminary quantitative study with susceptibility-weighted imaging

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Neural Regeneration Research 2010年第10期5卷 725-728页

作者： jun zhang Jianhong wang ke Li Daoying Geng Meirong Chen Weijun tang Zhenguo Zhao Yuehua Li Shiguo Ma Chenggong yan Department of Radiology Huashan Hospital Fudan University Shanghai 200040 China Department of Neurology Huashan Hospital Fudan University Shanghai 200040 China Department of Radiology Pudong New Area People's Hospital Shanghai 201200 China Department of Radiology Pudong New Area Hospital of Traditional Chinese Medicine Shanghai 201200 China

BACKGROUND： Studies have demonstrated iron deposition in Alzheimer＇s disease （AD） patients. Therefore, quantitative measurements and tracing of iron deposition are important for early detection and ***： To quantitatively measure iron deposition in the brain and evaluate the relationship between iron deposition and AD using magnetic susceptibility-weighted imaging. DESIGN, TIME AND SETTING： A case-control study was performed at the Department of Radiology, Huashan Hospital of Fudan University from February to July 2008. PARTICIPANTS： A total of 20 AD patients, comprising 11 males and 9 females, with a mean age of 72.5 years （range, 51-80 years）, and 20 healthy volunteers, comprising 10 males and 10 females, with a mean age of 69.9 years （range, 55-78 years）, were selected. AD was diagnosed according to the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer Disease and Related Disorders Association ***： Sagittal T2-weighted images were acquired to locate precise positions of the anterior and posterior commissures. The susceptibility-weighted magnetic resonance images were parallel to the anterior-posterior commissural line through the use of a three-dimensional gradient-echo sequence. All participants underwent measurement of corrected phase （CP） value and Mini-Mental State Examination. Pearson correlation coefficients were used to assess the association between CP values and Mini-Mental State Examination *** OUTCOME MEASURES： CP values of regions of interest in the hippocampal regions were measured on CP ***： CP values were significantly reduced in bilateral hippocampal regions of AD patients compared with normal controls （P〈0.01）, but there were no significant differences between left and right CP values （P〉0.05）. The hippocampal mean CP value positively correlated with the Mini-Mental State Examination score in AD patients and normal controls （r= 0.57, P〈0.01）. CONCLUSION： Susceptibil

关键词： magnetic resonance imaging hippocampus Alzheimer's disease neurodegenerative diseases neural regeneration

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Improving chitosan-based composite membrane by introducing a novel hybrid functional nano-hydroxyapatite with carboxymethyl cellulose and phytic acid

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Frontiers of Chemical Science and Engineering 2024年第6期18卷 1-15页

作者： Liuyun Jiang Yingjun Ma Shuo tang Yuqing wang yan zhang Shengpei Su Xiang Hu jun He National&Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources Key Laboratory of Chemical Biology&Traditional Chinese Medicine Research(Ministry of Education)College of Chemistry and Chemical EngineeringHunan Normal UniversityChangsha 410081China State key Laboratory Developmental Biology of Freshwater Fish School of Life ScienceHunan Normal UniversityChangsha 410081China Hunan Provincial key Laboratory of Regional Hereditary Birth Defects Prevention and Control Changsha Hospital for Matemal&Child Health Care Aiffiliated to Hunan Normal UniversityChangsha 410081China

A functional hybrid nano-hydroxyapatite(carboxymethyl cellulose-phytic acid-n-HA,CMC-PA-n-HA)was prepared by adding CMC and *** results of Fourier transformation infrared spectra,X-ray diffraction,thermal gravimetric analysis and dispersion experiments indicated that the addition of CMC and PA affected the morphology,crystallinity and crystal size of hybrid n-HA,and CMC endowed hybrid n-HA with excellent *** electron microscope results showed that CMC-PA-n-HA nanoparticle could be uniformly dispersed in chitosan(CS)matrix to obtain composite membrane by casting technology,so that the highest tensile strength of CMC-PA-n-HA/CS composite membrane was 69.64%and 144.45%higher than that of CS membrane and n-HA/CS composite membrane,*** angle test showed that CMC-PA-n-HA effectively improved hydrophilicity of the CS *** simulated body fluid immersion results indicated that the CMC-PA-n-HA/CS composite membrane not only exhibited good degradability but also promoted bone-like apatite *** cell proliferation experiments proved that the introduction of PA made the composite membrane have better cell adhesion and proliferation *** tests demonstrated that PA could effectively improve the antibacterial properties of the composite membrane,which is expected to be applied as guide bone tissue regeneration membrane.

关键词： nano-hydroxyapatite chitosan dispersion guide bone tissue regeneration membrane

RepDDNet:a fast and accurate deforestation detection model with high-resolution remote sensing image

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International Journal of Digital Earth 2023年第1期16卷 2013-2033页

作者： Zhipan wang Zhongwu wang Dongmei yan Zewen mo Hua zhang Qingling zhang Shenzhen key Laboratory of Intelligent Microsatellite Constellation Sun Yat-sen UniversityShenzhenPeople’s Republic of China Land Satellite Remote Sensing Application Center Ministry of Natural ResourcesBeijingPeople’s Republic of China Aerospace Information Research Institute Chinese Academy of SciencesBeijingPeople’s Republic of China Changsha University of Science&Technology ChangshaPeople’s Republic of China

Forest is the largest carbon reservoir and carbon absorber on ***,mapping forest cover change accurately is of great significance to achieving the global carbon neutrality *** forest change information could be acquired by deep learning methods using high-resolution remote sensing ***,deforestation detection based on deep learning on a large-scale region with high-resolution images required huge computational ***,there was an urgent need for a fast and accurate deforestation detection *** this study,we proposed an interesting but effective re-parameterization deforestation detection model,named *** other existing models designed for deforestation detection,the main feature of RepDDNet was its decoupling feature,which means that it allowed the multi-branch structure in the training stages to be converted into a plain structure in the inference stage,thus the computation efficiency can be significantly improved in the inference stage while maintaining the accuracy unchanged.A large-scale experiment was carried out in Ankang city with 2-meter high-resolution remote sensing images(the total area of it was over 20,000 square kilometers),and the result indicated that the model computation efficiency could be improved by nearly 30%compared with the model without ***,compared with other lightweight models,RepDDNet also displayed a trade-off between accuracy and computation efficiency.

关键词： Carbon neutral deforestation detection high-resolution remote sensing image deep learning reparameterization