检索结果-南通市图书馆

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

在线全文

学校读者我要写书评

暂无评论

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 ${\bm~{Einstein~~Probe}}$

BSA-lysozyme coated naCa_(2)HSi_(3)O_(9)nanorods on titanium for cytocompatibility and antibacterial activity

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第29期88卷 240-249页

作者： Yang xue Jun chen lan zhang Yong han State-key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong UniversityXi'an 710049China Department of Osteology Xi'an People’s Hospital(Xi'an No.4 Hospital)Xi'an 710100China Department of Osteology Tangdu HospitalFourth Military Medical UniversityXi'an 710038China

Extracellular supplement of Ca and Si accelerates osteogenisis and angiogenisis during bone ***-based ceramics are biodegradable and can release Ca and Si ions ***,locally high alkalinity induced by excessively rapid degradation limits their *** this paper,naCa_(2)HSi_(3)O_(9)(NCS)nanorods were fabricated on Ti by micro-arc oxidation and hydrothermal treatment;protein layers consisted of different rations of bovine serum albumin(BSA)and lysozyme(LYS)were prepared on NCS nanorods by spinning coating and thermal *** microstructure,ion releasing and wettability of coatings were observed;osteoblast and endotheliocyte behaviors,as well as bacteria response in vitro,were *** protein layer did not change microstructure and phase composition of nanorods but acted as a barrier isolating nanorods from contacting medium,and it results in slowing down the degradation of *** reduced increase of pH value,released Ca and Si ions and incorporation of LYS in BSA protein layer gave NCS nanorods improved MC3 T3-E1 and HUVECs response,compared with ***,the protein layers except pure LYS endowed nanorods with a highly antibacterial effect against staphylococcus aureus and escherichia coli simultaneously,indicating the key role of BSA in resisting antibacterial *** nanorods with BSA and LYS composited protein layers should be a potential coating applied on Ti implants for increasing osseointegration.

关键词： naCa_(2)HSi_(3)O_(9)nanorods bovine serum albumin Lysozyme Antibacterial activity Cytocompatibility

Numerical study on the wave pattern characteristic of air layer in cavity and the effects of multiple influence factors

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2023年第5期35卷 923-941页

作者： xiao-song zhang xue-qin Ji Lei-qiang chen Li-jin Gao hong-bo Huang Fang-wen hong CSSC shanghai Marine Energy Saving Technology Co.Ltd. Shanghai200011China China Ship Scientific Research Center shanghai Branch Shanghai200011China China Ship Scientific Research Center Wuxi214082China School of naval Architecture Ocean and Civil EngineeringState Key Laboratory of Ocean EngineeringShanghai Jiao Tong UniversityShanghai200240China

Air-layer drag reduction (ALDR) technology for ship energy saving is getting more and more attention in recent years because of the outstanding drag reduction effect. In order to promote practical application, it is necessary to fully understand the two phase flow characteristics of the air layer. Recent experimental studies have shown that the surface of the air layer presents wave pattern, which has an important influence on its damage risk. However, it is difficult to measure the wave pattern quantificationally due to the interference of equipment. The main goal of the present paper is to investigate the wave pattern characteristic of air layer in cavity using numerical simulation method. On this basis, the effect of flow and geometric influence factors are discussed to understand the key control conditions. A computational fluid dynamics (CFD) numerical method based on Reynolds averaged navier-Stokes (RANS) equations and volume of fluid (VOF) interface capturing method is established, and has been successfully applied in the simulation of air layer wave pattern. both 2-D and 3-D simulations are carried out, aiming at analyzing air-water interface flow and vortex flow directly. Based on the simulation results, several important conclusions about the mechanism of air layer wave pattern can be obtained. Firstly, it is found to be an inherent characteristic that the wave height of the upstream air layer is higher than that of the downstream. The extremely high wave peak is easy to contact with the flat plate, leading to the breakup of air layer and a “central blank area” phenomenon. With the help of flow analysis, it is found that this characteristic is mainly caused by the strong counterclockwise vortex behind the bow wedge block. Secondly, the air layer stability is reduced with the increase of water flow velocity by affecting the wave height. There is a saturation point of air flow rate to reach maximum thickness of air layer. Thirdly, cavity configuration has ob

关键词： Air layer drag reduction wave pattern of air-water interface numerical simulation multiple influence factors vortex flow fields

Autologous transplantation with fewer fibers repairs large peripheral nerve defects

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2017年第12期12卷 2077-2083页

作者： Jiu-xu deng Dian-yin zhang Ming Li Jian Weng Yu-hui Kou Pei-xun zhang na han bo chen xiao-feng Yin Bao-guo Jiang Department of Orthopedics and Trauma Peking University People's Hospital Beijing China

Peripheral nerve injury is a serious disease and its repair is challenging. A cable-style autologous graft is the gold standard for repairing long peripheral nerve defects; however, ensuring that the minimum number of transplanted nerve attains maximum therapeutic effect remains poorly understood. In this study, a rat model of common peroneal nerve defect was established by resecting a 10-mm long right common peroneal nerve. Rats receiving transplantation of the common peroneal nerve in situ were designated as the in situ graft group. Ipsilateral sural nerves（10–30 mm long） were resected to establish the one sural nerve graft group, two sural nerves cable-style nerve graft group and three sural nerves cable-style nerve graft group. Each bundle of the peroneal nerve was 10 mm long. To reduce the barrier effect due to invasion by surrounding tissue and connective-tissue overgrowth between neural stumps, small gap sleeve suture was used in both proximal and distal terminals to allow repair of the injured common peroneal nerve. At three months postoperatively, recovery of nerve function and morphology was observed using osmium tetroxide staining and functional detection. The results showed that the number of regenerated nerve fibers, common peroneal nerve function index, motor nerve conduction velocity, recovery of myodynamia, and wet weight ratios of tibialis anterior muscle were not significantly different among the one sural nerve graft group, two sural nerves cable-style nerve graft group, and three sural nerves cable-style nerve graft group. These data suggest that the repair effect achieved using one sural nerve graft with a lower number of nerve fibers is the same as that achieved using the two sural nerves cable-style nerve graft and three sural nerves cable-style nerve graft. This indicates that according to the ‘multiple amplification＇ phenomenon, one small nerve graft can provide a good therapeutic effect for a large peripheral nerve defect.

关键词： nerve regeneration peripheral nerve injury peripheral nerve defect autologous nerve graft functional recovery nerve conductionvelocity sural nerve common peroneal nerve sleeve bridging suture neural regeneration

Multifractal estimation of NMR T_(2) cut-off value in low-permeability rocks considering spectrum kurtosis: SMOTE-based oversampling integrated with machine learning

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2023年第6期20卷 3411-3427页

作者： xiao-Jun chen Rui-xue zhang xiao-bo Zhao Jun-Wei Yang zhang-Jian lan cheng-Fei Luo Jian-Chao Cai MOE Key Laboratory of Tectonics and Petroleum Resources Wuhan430074HubeiChina Department of Chemical Engineering and Analytical Science The University of ManchesterManchesterM139PLUK Jianghan Oilfied SINOPECQianjiang430063HubeiChina Hainan Branch of CNOOC Ltd Haikou570311HainanChina CNOOC EnerTech-Drilling&Production Co.CNOOC Central Laboratory(Zhanjiang) Zhanjiang524057GuangdongChina national Key Laboratory of Petroleum Resources and Engineering China University of PetroleumBeijing102249China

The transverse relaxation time (T_(2)) cut-off value plays a crucial role in nuclear magnetic resonance for identifying movable and immovable boundaries, evaluating permeability, and determining fluid saturation in petrophysical characterization of petroleum reservoirs. This study focuses on the systematic analysis of T_(2) spectra and T_(2) cut-off values in low-permeability reservoir rocks. Analysis of 36 low-permeability cores revealed a wide distribution of T_(2) cut-off values, ranging from 7 to 50 ms. Additionally, the T_(2) spectra exhibited multimodal characteristics, predominantly displaying unimodal and bimodal morphologies, with a few trimodal morphologies, which are inherently influenced by different pore types. Fractal characteristics of pore structure in fully water-saturated cores were captured through the T_(2) spectra, which were calculated using generalized fractal and multifractal theories. To augment the limited dataset of 36 cores, the synthetic minority oversampling technique was employed. Models for evaluating the T_(2) cut-off value were separately developed based on the classified T_(2) spectra, considering the number of peaks, and utilizing generalized fractal dimensions at the weight hanism is that the singular intensity and generalized fractal dimensions at the weight 0. The primary objective of this work is to gain insights into the relationship between the kurtosis of the T_(2) spectrum and pore types, as well as to predict the T_(2) cut-off value of low-permeability rocks using machine learning and data augmentation techniques.

关键词： Nuclear magnetic resonance Low-permeability porous media T_(2)cut-off value Fractal and multifractal Data augmentation Machine learning

Performance of the CENDL-3.2 and other major neutron data libraries for criticality calculations

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2022年第1期33卷 81-97页

作者： bin zhang Xu-bo Ma Kui Hu Teng zhang Xuan Ma Yi-xue chen School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China

Nuclear data are the cornerstones of reactor physics and shielding ***,China released CENDL-3.2 in 2020,and the US released ENDF/B-VIII.0 in ***,it is necessary to comprehensively evaluate the criticality computing performance of these newly released evaluated nuclear *** this study,we used the NJOY2016 code to generate ACE format libraries based on the latest neutron data libraries(including CENDL-3.2,JEFF3.3,ENDF/B-VIII.0,and JENDL4.0).The MCNP code was used to conduct a detailed analysis of fission nuclides,including^(235)U,^(233)U,and^(239)Pu,in different evaluated nuclear data libraries based on 100 *** criticality calculation performance of each library was evaluated using three statistical parameters:δk/σ,χ^(2),and.Analysis of theδk/σparameter showed that CENDL-3.1 and JENDL-4.0 both had>10 benchmarks that exceeded 3r,whereas CENDL3.2,ENDFB-VIII.0,and JEFF-3.3 had,7,5,and 4 benchmarks,respectively,exceeding *** ENDF/B-VII.1 library performed best,with only two benchmarks exceeding *** to CENDL-3.1,CENDL-3.2 offers an improvement in criticality *** to the JEFF-3.3 and ENDF/B-VIII.0 libraries,CENDL3.2 performs better in the calculation of the^(233)U assemblies,but it performs poorly in the pusl11 series case calculation of the^(239)Pu assemblies,and thus further improvement is needed.

关键词： Criticality calculations CENDL-3.2 ENDF/B-VIII.0 Neutron ACE library

Experimental study on smelting reduction of carbon-bearing manganese briquettes in slag bath

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2018年第4期25卷 417-425页

作者： bo zhang Da-ping Wang bin chen Zhen-jian Su Zheng-liang xue School of Metallurgical and Material Engineering Hunan University of Technology Zhuzhou 412007 Hunan China The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology Wuhan 430081 Hubei China

The reduction of carbon-bearing manganese briquettes in a slag bath was experimentally investigated at temperatures ranging from 1550 to 1650 ℃. both the internal temperature and the microstructure evolution of the briquettes were analyzed by differential thermal analysis, scanning electron microscopy and energy-dispersive spectrum analysis, and the smelting reduction mechanism of the carbon-bearing manganese briquettes in the slag bath was further elaborated. The results indicated that the smelting reduction of the briquettes in the slag bath could be divided into three stages, and the aggregation and growth of the metallic particles during the reduction were significantly affected by the slag temperature. Under the experimental conditions, the reduction speed at the initial stage of the carbon-bearing manganese briquettes smelting reduction was controlled by the chemical reaction, whereas the reaction speeds at both the middle and following stages were limited by gaseous diffusion.

关键词： Slag bath Smelting reduction Carbon-bearing briquette Kinetics

Deep image synthesis from intuitive user input:A review and perspectives

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computational Visual Media 2022年第1期8卷 3-31页

作者： Yuan xue Yuan-chen guo han zhang Tao Xu Song-Hai zhang xiaolei Huang College of Information Sciences and Technology the Pennsylvania State UniversityUniversity ParkPAUSA Department of Computer Science and Technology Tsinghua UniversityBeijingChinaand Beijing National Research Center for Information Science and Technology(BNRist)Tsinghua UniversityBeijingChina Google Brain Mountain ViewCAUSA Facebook Menlo ParkCAUSA.

In many applications of computer graphics,art,and design,it is desirable for a user to provide intuitive non-image input,such as text,sketch,stroke,graph,or layout,and have a computer system automatically generate photo-realistic images according to that *** classically,works that allow such automatic image content generation have followed a framework of image retrieval and composition,recent advances in deep generative models such as generative adversarial networks(GANs),variational autoencoders(VAEs),and flow-based methods have enabled more powerful and versatile image generation *** paper reviews recent works for image synthesis given intuitive user input,covering advances in input versatility,image generation methodology,benchmark datasets,and evaluation *** motivates new perspectives on input representation and interactivity,cross fertilization between major image generation paradigms,and evaluation and comparison of generation methods.

关键词： image synthesis intuitive user input deep generative models synthesized image quality evaluation

Analyses of risk factors and prognosis for new-onset atrial fibrillation in elderly patients after dual-chamber pacemaker implantation

在线全文

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2018年第10期15卷 628-633页

作者： xiao-Li chen xue-Jun REN Zhuo LIANG Zhi-hong han Tao zhang Zhi LUO Department of Cardiology Beijing Geriatric HospitalBeijingChina Department of Cardiology Beijing Anzhen HospitalCapital Medical UniversityBeijingChina

Objective To retrospectively identify risk factors and the prognosis for new-onset atrial fibrillation (AF)after implantation of dual-chamber pacemakers in elderly *** Consecutive patients aged >65years who underwent their first implantation of a dual-chamber permanent pacemaker in Beijing Anzhen Hospital from October 2013to May 2016were *** complete program- ming and follow-up data were ***-up end points included new-onset AF and major adverse cardiovascular and cerebrovascular *** Altogether,322patients were enrolled,with new-onset AF observed in 79(24.5%)during their *** analysis identified four independent predictors of new-onset AF in elderly patients after pacemaker implantation:hypertension (HR =3.040, 95%CI:1.09-3.05,P =0.00),age (HR =1.966,95%CI:1.57-3.68,P =0.01);left atrial enlargement (HR =1.645,95%CI:1.05-1.25,P = 0.03);high ventricular pacing rate (HR =1.137,95%CI:1.01-1.06,P =0.01).Univariable analysis indicated that the CHA2DS2-VASc score was also a risk factor for AF (HR =1.368,95%CI:1.178-1.589,P =0.002),whereas multivariable regression analysis did not. Kaplan-Meier survival analysis showed that the risk for ischemic stroke was significantly higher in the new-onset AF group than in the non-AF group (P lantation of a permanent ***-onset AF increased the risk for ischemic stroke.

关键词： Atrial fibrillation Dual-chamber pacemaker Elderly Ischernic stroke