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68卷 218-236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 SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Institute of Space Sciences(ICE) CSICBarcelona E-08193Spain Institut d’Estudis Espacials de Catalunya(IEEC) Barcelona E-08034Spain Max Planck Institute for Extraterrestrial Physics Garching 85748Germany Innovation Academy for Microsatellites Chinese Academy of SciencesShanghai 201210China Department of Physics University of Hong KongHong Kong 999077China School of Physics and Astronomy University of LeicesterLeicester LE17RHUK School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China Department of Physics Anhui Normal UniversityWuhu 241002China Shanghai Institute of Technical Physics Chinese Academy of SciencesShanghai 200083China Physics Department Tsinghua UniversityBeijing 100084China Nevada Center for Astrophysics University of Nevada Las VegasLas Vegas NV 89154USA Department of Physics and Astronomy University of Nevada Las VegasLas Vegas NV 89154USA South African Astronomical Observatory Cape Town 7935South Africa Department of Astronomy University of Cape TownRondebosch 7701South Africa Department of Physics University of the Free StateBloemfontein 9300South Africa Universit´e Paris Cit´e CNRSAstroparticule et CosmologieParis F-75013France Universit´e Paris Cit´e CEA Paris-SaclayIRFU/DAp-AIMGif-sur-Yvette 91191France Department of Astronomy Guangzhou UniversityGuangzhou 510006China Cosmic Dawn Center(DAWN) Copenhagen 2200Denmark Niels Bohr Institute University of CopenhagenCopenhagen 2200Denmark Department of Physics and Astronomy Rutgersthe State University of New JerseyPiscataway NJ 08854-8019USA Institute for Cosmic Ray Research The University of TokyoKashiwa City 277-8582Japan ESA/ESTEC Noordwijk 2201 AZThe Netherlands Department of Astronom

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 12 *** flare reached a peak flux of 3:9×10^(−9) erg cm^(−2) s^(−1) in 0.5-4 keV,∼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 keV,with a power-law photon index varying within *** 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 Einstein Probe

The Lyman-alpha Solar Telescope(LST) for the ASO-S mission——Ⅱ. design of LST

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2019年第11期19卷 33-48页

作者： Bo Chen Hui li Ke-Fei Song Quan-Feng Guo Pei-Jie Zhang ling-Ping He Shuang Dai Xiao-Dong Wang Hai-Feng Wang Chun-Long liu hong-Ji Zhang Guang Zhang Yunqi Wang Shi-Jie liu hong-xin Zhang Lei liu Shi-Lei Mao Yang liu Jia-Hao Peng Peng Wang liang Sun Yang liu Zhen-wei Han Yan-Long Wang Kun Wu Guang-xing Ding Peng Zhou xin Zheng Ming-Yi Xia Qing-Wen Wu Jin-Jiang Xie Ya Chen Shu-Mei Song hong Wang Bo Zhu Chang-Bo Chu Wen-Gang Yang li Feng Yu Huang wei-Qun Gan Ying li Jing-wei li Lei Lu Jian-Chao Xue Bei-li Ying Ming-Zhe Sun Cheng Zhu wei-Min Bao Lei Deng zeng-Shan Yin Changchun Institute of Optics FineMechanics and PhysicsChinese Academy of SciencesChangchun 130033China State Key Laboratory of Applied Optics Changchun 130033China Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210034China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Xi’an Institute of Optics and Precision Mechanics Chinese Academy of SciencesXi’an 710119China Shandong University Weihai 264209China Innovation Academy for Microsatellites Chinese Academy of SciencesShanghai 201210China

As one of the three payloads for the Advanced Space-based Solar Observatory(ASO-S)mission,the Lyman-alpha(Lyα)Solar Telescope(LST)is composed of three instruments:a Solar Corona Imager(SCI),a LyαSolar Disk Imager(SDI)and a full-disk White-light Solar Telescope(WST).When working in-orbit,LST will simultaneously perform high-resolution imaging observations of all regions from the solar disk to the inner corona up to 2.5 R⊙(R⊙stands for the mean solar radius)with a spatial resolution of 4.8′′and 1.2′′for coronal and disk observations,respectively,and a temporal resolution of 30–120 s and 1–120 s for coronal and disk observations,*** maximum exposure time can be up to20 s due to precise pointing and image stabilization *** the three telescopes of LST,SCI is a dual-waveband coronagraph simultaneously and independently observing the inner corona in the HI Lyα(121.6±10 nm)line and white light(WL)(700±40 nm)wavebands by using a narrowband Lyαbeam splitter and has a field of view(FOV)from 1.1 to 2.5 R⊙.The stray-light suppression level can attainline and 360.0 nm wavebands,respectively,which adopt an off-axis two-mirror reflective structure with an FOV up to 1.2 R⊙,covering the inner coronal edge area and relating to coronal *** present the up-to-date design for the LST payload.

关键词： telescopes—instrumentation high angular resolution—Sun flares—Sun coronal mass ejections(CMEs)—Sun UV radiation

Genetic Polymorphism of PSCA and Risk of Advanced Precancerous Gastric Lesions in a Chinese Population

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 2010年第2期22卷 99-105页

作者： hong-mei Mu Chen Wu lian Zhang Kai-feng Pan Jun-ling Ma Yang Zhang Wen-qing li Hua-kang Tu hong-mei zeng wei-dong liu Tong Zhou Dong-xin lin wei-cheng You Key Laboratory of Carcinogenesis and Translational Research （Ministry of Education） Department of Epidemiology Peking University School of Oncology Beijing Cancer Hospital ＆ Institute Beijing 100142 China Department of Etiology and Carcinogenesis Cancer Institute and Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100021 China linqu Public Health Bureau Linqu Shandong China

Objective： To evaluate the relationship between the genetic polymorphism of prostate stem cell antigen （PSCA） and the risk of advanced precancerous gastric lesions including intestinal metaplasia（IM） and dysplasia（Dys）, a population-based study was conducted in linqu County, a high-risk area of gastric cancer （GC） in China. Methods： The prevalence of gastric lesions including superficial gastritis（SG）, chronic atrophic gastritis（CAG）, IM and Dys was determined by histopathologic examination. The genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） technique. The effects of PSCA genetic variant on the risks of IM and Dys were calculated by unconditional logistic regression. Results： Multivariate analysis revealed subjects carrying PSCA rs2294008 CT/TT genotype were associated with an increased risk of IM （OR=1.38, 95% CI=1.11-1.71） and Dys （OR=1.75, 95% CI=1.36-2.26）, especially for subjects with *** infection （IM： OR=1.34, 95% CI=1.05-1.71; Dys： OR=1.82, 95% CI=1.37-2.42）. Furthermore, H. pylori infection and PSCA rs2294008 CT/TT genotype were observed to jointly elevate the risk of IM （OR=3.32, 95% CI=2.33-4.71） and Dys （OR=4.58, 95% CI=2.99-7.04）. Conclusion： This study suggested that PSCA rs2294008 might have an impact on the risk of IM or Dys among the high risk population of GC.

关键词： Polymorphism Prostate stem cell antigen Advanced precancerous gastric lesions Helicobacterpylori

A practical community-based response strategy to interrupt Ebola transmission in sierra Leone, 2014–2015

在线全文

学校读者我要写书评

暂无评论

Infectious Diseases of Poverty 2016年第1期5卷 670-679页

作者： Zhong-Jie li Wen-Xiao Tu Xiao-Chun Wang Guo-Qing Shi Zun-Dong Yin Hai-Jun Su Tao Shen Da-Peng Zhang Jian-Dong li Shan Lv Chun-li Cao Rui-Qian Xie hong-Zhou Lu Rong-Meng Jiang Zheng Cao Zhi-Jie An Lei-Lei li Jie Xu Yan-Wen Xiong wei Zang wei Zhang hong-wei Zhang Wen-Sen Chen Hua ling Wen Xu Jian Cai Huan-Jin Luo Xue-Sheng xing Can-Jun Zheng Qiang wei xin-Xu li Mei li Hai Jiang li-Quan Deng Ming-Quan Chen Xiang Huo Feng Xu Xue-Hui Lai Xi-Chen Bai Long-Jie Ye Jian-Yi Yao Wen-Wu Yin Jiao-Jin Sun lin Xiao Fu-Qiang liu Xiao-Qiang liu hong-wei Fan zeng-Qiang Kou Ji-Kun Zhou Hao Zhang Da-xin Ni Thomas TSamba Qun li hong-Jie Yu Yu Wang Xiao-Feng liang Division of Infectious Disease Key Laboratory of Surveillance and Early-warning on Infectious DiseaseChinese Center for Disease Control and PreventionBeijingChina Public Health Emergency Center Chinese Center for Disease Control and PreventionBeijingChina National Center for AIDS/STD Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina Chinese Field Epidemiology Training Program Chinese Center for Disease Control and PreventionBeijingChina National Immunization Program Chinese Center for Disease Control and PreventionBeijingChina Bureau of Disease Prevention and Control National Health and Family Planning Commission of the People’s Republic of ChinaBeijingChina National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina National Institute of Parasitic Disease Chinese Center for Disease Control and PreventionShanghaiChina Chinese Center for Health Education BeijingChina Department of Infectious Diseases Shanghai Public Health Clinical CenterShanghaiChina Beijing Ditan Hospital Capital Medical UniversityBeijingChina Health News BeijingChina National Institute for Communicable Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina Department of Training Chinese Center for Health EducationBeijingChina Center for Infectious Diseases Beijing Youan HospitalCapital Medical UniversityBeijingChina Infection Management The First Affiliated Hospital of Nanjing Medical UniversityNanjingChina Chongqing Municipal Center for Disease Control and Prevention ChongqingChina Yunnan Provincial Center for Disease Control and Prevention KunmingChina Division of Infectious Disease Control and Prevention Zhejiang Provincial Center for Disease Control and PreventionHangzhouChina Guangdong Provincial Center for Disease Control and Prevention GuangzhouChina Division of Acute Infectious Disease Control and Prevention Hubei Provincial Center for Disease Control and PreventionW

Background:The Ebola virus disease spread rapidly in West Africa in 2014,leading to the loss of thousands of *** engagement was one of the key strategies to interrupt Ebola transmission,and practical community level measures needed to be explored in the field and tailored to the specific context of ***:First,community-level education on Ebola virus disease(EVD)prevention was launched for the community’s social mobilizers in six districts in Sierra Leone beginning in November ***,from January to May of 2015,in three pilot communities,local trained community members were organized to engage in implementation of EVD prevention and transmission interruption measures,by involving them in alert case report,contact tracing,and social *** epidemiological indicators of transmission interruption in three study communities were ***:A total of 6016 community social mobilizers from 185 wards were trained by holding 279 workshops in the six districts,and EVD message reached an estimated 631680 *** three pilot communities,72 EVD alert cases were reported,with 70.8%of them detected by trained local community members,and 14 EVD cases were finally *** tracing detected 64.3%of EVD *** median duration of community infectivity for the cases was 1 *** secondary attack rate was 4.2%,and no third generation of infection was *** health worker was infected,and no unsafe burial and noncompliance to EVD control measures were *** community-based measures were modeled to reduce 77 EVD cases,and the EVD-free goal was achieved four months earlier in study communities than whole country of Sierra ***: The community-based strategy of social mobilization and community engagement was effective in casedetection and reducing the extent of Ebola transmission in a country with weak health system. The successfullypractical experience to reduce the risk of Ebola transmission in the

关键词： Ebola virus disease Community engagement Health education Outbreak control

Medical Additive Manufacturing: From a Frontier Technology to the Research and Development of Products

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

Engineering 2020年第11期6卷 1217-1221页

作者： Guixing Qiu Wenjiang Ding wei Tian ling Qin Yu Zhao lianmeng Zhang Jian Lu Daijie Chen Guangyi Yuan Chengtie Wu Bingheng Lu Ruxu Du Jimin Chen mo Elbestawi Zhongwei Gu Dichen li wei Sun Yuanjin Zhao Jie He Dadi Jin Bin liu Kai Zhang Jianmo li Kam WLeong Dewei Zhao Dingjun Hao Yingfang Ao Xuliang Deng Huilin Yang ShaoKeh Hsu Yingqi Chen Long li Jianping Fan Guohui Nie Yun Chen Hui zeng wei Chen Yuxiao Lai Department of Orthopedics Peking Union Medical College HospitalChinese Academy of Medical Science 8 Peking Union Medical CollegeBejjing 100730.China National Engineering Research Center of light Alloys Net Forming&State Key Laboratony of Metal Matrix Composite Shanghai Jiao Tong UniversityShanghai 200240China Notional Engineering Research Center of Mg Materials and Applicarions and School of Materials Science 8r Engineering.Shanghai Jlao Tong University Shanghai 200240China Department of Spine Surgery Beijing Jishuitan HospitalBeijing 100035China Center for Troanslational Medicine Research and Development Institute of Biomedical and Health EngineeringShenzhen Insitute of Advanced Technology.Chinese Academy of SciencesShenzhen 518055China Guangdong Engineering Laboratony of Biomaterials Additive Manufacturing Guangdong 518055China Musculoskeletal Research Laboratory of the Department of Orthopedics 8 Traumatology and Innovative Orthopedic Biomaterial and Drug Translational Research Laboratory Li Ka Shing Institute of Health SciencesThe Chinese University of Hong KongHong Kong 999077.China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Center for Advanced Structural Materials City University of Hong Kong Shenzhen Research InstiuteShenzhen 518057.China hong Kong Branch of National Precious Metals Material Engineering Research Center Department of Material Science and EngineeringCity Untiversity of Hong KongHong Kong 999077.China Department of Mechanical Engineering ity Untiversity of Hong Kong.Hong Kong 9977 China School of Pharmacy.Shanghai Jiao Tong University Shanghai 200240China China State Instute of Pharmaceutical Industry Shanghai Institute of Pharmaceutical IndustryShonghai 201203China Shanghai Innovation Instinute for Materials Shanghai 200444.China State Key Laboratory of High-Performance Ceramies and Superfine Microstructure Shanghai Institute of CeramicsChinese Acadermy 0f SciencesShanghai 200050Ch

*** and development(R&D)and the challenges of raw materials for medical additive manufacturing Raw materials for medical additive manufacturing have a wide range of commonalities that are also seen in many other fields,making them an important basis in the field of three-dimensional(3D)*** and challenges related to material types,powder properties,formability,viscoelasticity,and so forth also share common *** example,many metal materials are used in the field of aviation,while metals,polymers,and inorganic materials are used in the field of *** most widely used materials in biomedicine are *** homogeneous and non-homogeneous composites are also available for 3D printing,and impose an additional challenge in additive manufacturing;the use of heterogeneous composites in 3D printing is particularly challenging.

关键词： composites printing additive

Study of the response of 10B-doped MCP to wide-energy range neutrons from eV to MeV

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

Nuclear Science and Techniques 2024年第8期35卷 132-141页

作者： Qiang li li‑Jiao Wang Xiang‑Biao Qiu Jing‑Wen li wei Xu Tao li Ze‑Bin lin Chang‑Jun Ning Yong‑Hao Chen Rui‑Rui Fan Kang Sun Jing‑Yu Tang Rong Zhang Han‑Tao Jing Bo Mei Qi An Hao‑Fan Bai Jiang‑Bo Bai Jie Bao Ping Cao Qi‑Ping Chen Zhen Chen zeng‑Qi Cui An‑Chuan Fan Chang‑Qing Feng Fan‑Zhen Feng Ke‑Qing Gao Min‑Hao Gu Chang‑Cai Han Zi‑Jie Han Guo‑Zhu He Yong‑Cheng He Yang hong Yi‑wei Hu Han‑Xiong Huang wei‑Hua Jia Hao‑Yu Jiang wei Jiang Zhi‑Jie Jiang Zheng‑Yao Jin ling Kang Bo li Chao li Gong li Jia‑Wen li Xiao li Yang li Jie liu Rong liu Shu‑Bin liu Guang‑Yuan Luan Bin‑Bin Qi Jie Ren Zhi‑Zhou Ren Xi‑Chao Ruan Zhao‑Hui Song Zhi‑xin Tan Sheng‑Da Tang Peng‑Cheng Wang Zhao‑Hui Wang Zhong‑wei Wen Xiao‑Guang Wu Xuan Wu li‑Kun Xie Yi‑wei Yang Han Yi Yong‑Ji Yu Guo‑Hui Zhang lin‑Hao Zhang mo‑Han Zhang Qi‑wei Zhang Xian‑Peng Zhang Yu‑liang Zhang Yue Zhang Zhi‑Yong Zhang Mao‑Yuan Zhao Lu‑Ping Zhou Zhi‑Hao Zhou Ke‑Jun Zhu Institute of High Energy Physics Chinese Academy of Sciences(CAS)Beijing 100049China Spallation Neutron Source Science Center Dongguan 523803China State Key Laboratory of Particle Detection and Electronics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Dongguan Songshan Lake Future School Dongguan 523808China North Night Vision Science&Technology(Nanjing)Research Institute Co.Ltd. Nanjing 211106China Sino‑French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230027China State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China Department of modern Physics University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China Key Laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China USTC Archaeometry Lab University of Science and Technology of ChinaHefei 230026China Northwest Institute of Nuclear Technology Xi’an 710024China University of Chinese Academy of Sciences Beijing 100049China

Neutron-sensitive microchannel plates(nMCPs)have applications in neutron detection,including energy spectrum measurements,neutron-induced cross sections,and neutron imaging.10B-doped MCPs(B-MCPs)have attracted significant attention owing to their potential for exhibiting a high neutron detection efficiency over a large neutron energy *** spatial and temporal resolutions are useful for neutron energy-resolved ***,their practical applications still face many technical *** this study,a B-MCP with 10 mol%10B was tested for its response to wide-energy neutrons from eV to MeV at the Back-n white neutron source at the China Spallation Neutron *** neutron detection efficiency was calibrated at 1 eV,which is approximately 300 times that of an ordinary MCP and indicates the success of 10 B *** factors that caused the reduction in the detection efficiency were simulated and *** neutron energy spectrum obtained using B-MCP was compared with that obtained by other measurement methods,and showed very good consistency for neutron energies below tens of *** response is more complicated at higher neutron energy,at which point the elastic and nonelastic reactions of all nuclides of B-MCP gradually become *** is beneficial for the detection of neutrons,as it compensates for the detection efficiency of B-MCP for high-energy neutrons.

关键词： Neutron radiation image 10B-doped MCP Neutron response Wide-energy range neutrons

一类非单调修正β_k^(WYL)算法的全局收敛性

在线全文

学校读者我要写书评

暂无评论

广西大学学报（自然科学版） 2007年第2期32卷 101-105页

作者：莫利柳洪玲韦增欣广西大学数学与信息科学学院广西南宁530004

结合文[1]给出的新公式βkWYL,提出了一种非单调线搜索下的修正βkWYL算法,该方法保证每次迭代中的搜索方向是充分下降的.在较弱的条件下,我们证明了此类非单调修正βkWYL算法具有全局收敛性,数值试验表明该方法具有良好的数值结果.

关键词：修正βk^WYL算法非单调线搜索全局收敛性

在线全文

学校读者我要写书评

暂无评论

一类无约束优化问题的非单调谱共轭梯度方法

广西科学 2007年第4期14卷 374-377页

作者：莫利柳洪玲韦增欣广西大学数学与信息科学学院广西南宁530004

结合文献[5]给出的求解非线性无约束优化问题的新公式βkWYL=[gTk(gk-‖gk‖/‖gk-1‖gk-1)]/gk-1Tgk-1提出了一种新的非单调谱共轭梯度法,证明算法具有全局收敛性,并进行数值试验.数值试验结果表明,该方法具有良好的计算效能,特别适合... 详细信息

结合文献[5]给出的求解非线性无约束优化问题的新公式βkWYL=[gTk(gk-‖gk‖/‖gk-1‖gk-1)]/gk-1Tgk-1提出了一种新的非单调谱共轭梯度法,证明算法具有全局收敛性,并进行数值试验.数值试验结果表明,该方法具有良好的计算效能,特别适合于求解大规模无约束优化问题.

关键词：无约束优化共轭梯度法线搜索全局收敛性

在线全文

学校读者我要写书评

暂无评论

一个共轭梯度方法的全局收敛性

广西科学 2007年第3期14卷 239-243页

作者：洪玲莫利柳韦增欣广西大学数学与信息科学学院广西南宁530004

给出一种较弱的线搜索:寻找一个步长tk=jρkΔk满足f(xk+jρdk)-f(xk)≤αjρgkTdk-m2(jρ)2‖dk‖2,α∈(0,1),ρ∈(0,1),m>0和gkT+1dk+1<0,将此线搜索应用于求解共轭梯度公式的βk*,得到一种新共轭梯度算法,并证明新算法具有全局收敛... 详细信息

给出一种较弱的线搜索:寻找一个步长tk=jρkΔk满足f(xk+jρdk)-f(xk)≤αjρgkTdk-m2(jρ)2‖dk‖2,α∈(0,1),ρ∈(0,1),m>0和gkT+1dk+1<0,将此线搜索应用于求解共轭梯度公式的βk*,得到一种新共轭梯度算法,并证明新算法具有全局收敛,用数值实验说明新算法是有效的.

关键词：无约束优化共轭梯度法线搜索全局收敛性