检索结果-南通市图书馆

Focal plane wave-front sensing algorithm for high-contrast imaging

Science China(Physics,Mechanics & astronomy) 2009年第8期52卷 1284-1288页

作者： DOU JiangPei1,2,3,REN DeQing1,2,4.ZHU YongTian1,2 & ZHANG Xi1,2,3 1 National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology,Chinese Academy of Sciences,Nanjing 21004.,China 2 Key Laboratory of Astronomical Optics & Technology,Nanjing Institute of Astronomical Optics & Technology,Chinese Academy of Sciences,Nanjing 21004.,China 3 Graduate university of Chinese Academy of Sciences,Beijing 10004.,China 4.Physics & astronomy department,california state university northridge,{4.,northridge,california 913.0-8268,usa National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing 210042 China Key Laboratory of Astronomical Optics & Technology Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing 210042 China Graduate university of Chinese Academy of Sciences Beijing 100049 China Physics & astronomy department California State University Northridge 18111 Nordhoff Street Northridge California 91330-8268 USA

High-contrast imaging provided by a coronagraph is critical for the direction imaging of the Earth-like planet orbiting its bright parent star.A major limitation for such direct imaging is the speckle noise that is induced from the wave-front error of an optical *** derive an algorithm for the wave-front measurement directly from 3 focal plane *** 3 images are achieved through a deformable mirror to provide specific phases for the optics *** introduce an extra amplitude modulation on one deformable mirror configuration to create an uncorrelated wave-front,which is a critical procedure for wave-front *** simulation shows that the reconstructed wave-front is consistent with the original wave-front theoretically,which indicates that such an algorithm is a promising technique for the wave-front measurement for the high-contrast imaging.

关键词： high-contrast imaging multi-image algorithm speckle nulling technique wave-front sensing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An iterative wavefront sensing algorithm for high-contrast imaging systems

引用

Research in astronomy and Astrophysics 2011年第2期11卷 198-204页

作者： Jiang-Pei Dou 1,2,De-Qing Ren 1,2,3 and Yong-Tian Zhu 1,2 1 National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology,Chinese Academy of Sciences,Nanjing 21004.,China 2 Key Laboratory of Astronomical Optics & Technology,Nanjing Institute of Astronomical Optics & Technology,Chinese Academy of Sciences,Nanjing 21004.,China 3 Physics & astronomy department,california state university northridge,18111 nordhoff street,{4.,california 913.0-8268,usa National Astronomical Observatories / Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing 210042 China Key Laboratory of Astronomical Optics & Technology Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing 210042 China Physics & astronomy department California State University Northridge 18111 Nordhoff Street Northridge California 91330-8268 USA

Wavefront sensing from multiple focal plane images is a promising technique for high-contrast imaging ***,the wavefront error of an optics system can be properly reconstructed only when it is very *** paper presents an iterative optimization algorithm for the direct measurement of large static wavefront errors from only one focal plane *** first measure the intensity of the pupil image to get the pupil function of the system and acquire the aberrated image on the focal plane with a phase error that will be *** we induce a dynamic phase on the tested pupil function and calculate the associated intensity of the reconstructed image on the focal *** algorithm will then try to minimize the intensity difference between the reconstructed image and the aberrated test image in the focal plane,where the induced phase is a variable of the optimization *** simulation shows that the wavefront of an optical system can theoretically be reconstructed with high precision,which indicates that such an iterative algorithm may be an effective way to perform wavefront sensing for high-contrast imaging systems.

关键词： techniques: image processing -- methods: numerical -- planetarysystems

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Stochastic parallel gradient descent based adaptive optics used for a high contrast imaging coronagraph

引用

Research in astronomy and Astrophysics 2011年第8期11卷 997-1002页

作者： Bing Dong De-Qing Ren Xi Zhang Physics ＆ astronomy department California State University Northridge CA 91330-8268 USA National Astronomical Observatories/Nanjing Institute of Astronomical Optics ＆ Technology Chinese Academy of Sciences Nanjing 210042 China

An adaptive optics （AO） system based on a stochastic parallel gradient descent （SPGD） algorithm is proposed to reduce the speckle noises in the optical system of a stellar coronagraph in order to further improve the contrast. The principle of the SPGD algorithm is described briefly and a metric suitable for point source imaging optimization is given. The feasibility and good performance of the SPGD algorithm is demonstrated by an experimental system featured with a 14.-actuator deformable mirror and a Hartrnann-Shark wavefront sensor. Then the SPGD based AO is applied to a liquid crystal array （LCA） based coronagraph to improve the contrast. The LCA can modulate the incoming light to generate a pupil apodization mask of any pattern. A circular stepped pattern is used in our preliminary experiment and the image contrast shows improvement from 10^-3 to 10^-4.5 at an angular distance of 2A/D after being corrected by SPGD based AO.

关键词： instrumentation: adaptive optics -- methods: laboratory -- techniques: image processing coronagraph

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

NONLINEAR OPTICS IN QUANTUM WIRES

引用

中国科学院大学学报 1995年第1期 17-20页

作者： Chen Rei-min(department of Physics and astronomy, state university of New York at Buffalo Buffalo, New York 14.60-1500, {4. and department of Physics, Emory university, Atlanta, GA 30322, {4.)Lin Duo-liang (department of Physics, Hong Kong university of S

ＮＯＮＬＩＮＥＡＲＯＰＴＩＣＳＩＮＱＵＡＮＴＵＭＷＩＲＥＳ￥ＣｈｅｎＲｅｉ－ｍｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓａｎｄＡｓｔｒｏｎｏｍｙ，ＳｔａｔｅＵｎｉｖｅｒｓｉｔｙｏｆＮｅｗＹｏｒｋａｔＢｕｆｆａｌｏＢ... 详细信息

ＮＯＮＬＩＮＥＡＲＯＰＴＩＣＳＩＮＱＵＡＮＴＵＭＷＩＲＥＳ￥ＣｈｅｎＲｅｉ－ｍｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓａｎｄＡｓｔｒｏｎｏｍｙ，ＳｔａｔｅＵｎｉｖｅｒｓｉｔｙｏｆＮｅｗＹｏｒｋａｔＢｕｆｆａｌｏＢｕｆｆａｌｏ，ＮｅｗＹｏｒｋ１４２...

关键词： optical nonlinearity nonlinear optical susceptibility silicon quantum wires

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Optical Flash of GRB 990123: Constraints on the Physical Parameters of the Reverse Shock

引用

Chinese Journal of astronomy and Astrophysics 2002年第5期2卷 449-453页

作者： Yi-Zhong Fan, Zi-Gao Dai, Yong-Feng Huang and Tan Lu department of astronomy, Nanjing university, Nanjing 210093 department of astronomy Nanjing University Nanjing 210093

The optical flash accompanying GRB 990123 is believed to be powered by the reverse shock of a thin shell. With the best-fit physical parameters for GRB 990123 and the assumption that the parameters in the optical flash are the same as in the afterglow, we show that: 1) the shell is thick rather than thin, and we have provided the light curve for the thick shell case which coincides with the observation; 2) the theoretical peak flux of the optical flash accounts for only 3×10-4.of the observed. In order to remove this discrepancy, the physical parameters, the electron energy and magnetic ratios, εe and εB, should be 0.61 and 0.39, which are very different from their values for the late afterglow.

关键词： gamma rays: bursts - gamma rays: theory

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

X-ray spectra induced in highly charged 4.Ar^q+ interacting with Au surface

引用

Science China(Physics,Mechanics & astronomy) 2006年第2期49卷 203-212页

作者： ZHANG Xiao’an1,2, XIAO Guoqing1, YANG Zhihu1, CHEN Ximeng3, ZHAO Yongtao1, LI Fuli4. ZHANG Yinping1, CUI Ying3, ZHANG Hongqiang3, XU Xu3, SHAO Jianxiong3 & ZHAN Wenlong11. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China 2. department of Physics, Xianyang Normal university, Xianyang 712000, China 3. department of Modern Physics, Lanzhou university, Lanzhou 730000, China 4. department of Applied Physics, Xi’an Jiaotong university, Xi’an 71004., China 1. Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China 2. department of Physics Xianyang Normal University Xianyang 712000 China 3. department of Modern Physics Lanzhou University Lanzhou 730000 China 4. department of Applied Physics Xi’an Jiaotong University Xi’an 710049 China

By use of optical spectrum technology, the spectra of X-ray induced by highly charged 4.Arq+ ions interacting with Au surface have been studied. The results show that the argon Kα X-ray were emitted from the hollow atoms formed below the surface. There is a process of multi-electron exciting in neutralization of the Ar16+ion, with electronic con-figuration 1s2 in its ground state below the solid surface. The yield of the projectile Kα X-ray is related to its initial electronic configuration, and the yield of the target X-ray is related to the projectile kinetic energy.

关键词： highly charged ion hollow multi-electron excitation X- ray.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Searching for Top Squark at Hadron Colliders

引用

高能物理与核物理 2002年第Z1期26卷 25-33页

作者： YANG Jin-Min Young Bing-Lin (Institute of Theoretical Physics, CAS, Beijing 100080, China)(department of Physics and astronomy, Iowa state university, Ames, Iowa 50011, US A) Institute of Theoretical Physics CAS Beijing 100080 China Institute of Theoretical Physics CAS Beijing 100080 China department of Physics and astronomy Iowa State University Ames Iowa 50011 USA

In this talk we briefly summarise our recent study(hep-ph/0007165)on searching fortop squark at hadron *** light top-squark(stop)if produced in hadron colliders in theform of the (?)(?) pair and decaying through the l... 详细信息

关键词：高能物理核物理 QCD Searching for Top Squark at Hadron Colliders pair LHC

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Entropy product measure for multipartite pure states

引用

Science China(Physics,Mechanics & astronomy) 2006年第5期49卷 606-615页

作者： CAO Wancang1,2, LIU Dan2, PAN Feng3 & LONG Guilu2,4.1. department of Physics, Chifeng College, Chifeng 024.01, China 2. Key Laboratory for Quantum Information and Measurements, department of Physics, Tsinghua university, Beijing 100084. China 3. department of Physics, Liaoning Normal university, Dalian 116029, China 4. Key Laboratory for Atomic and Molecular Nano-Sciences, Tsinghua university, Beijing 100084. China Correspondence should be addressed to Long Guilu department of Physics Chifeng College Chifeng 024001 China Key Laboratory for Quantum Information Measurements Department of Physics Tsinghua University Beijing 100084 China department of Physics Liaoning Normal University Dalian 116029 China Key Laboratory for Atomic Molecular Nano-Sciences Tsinghua University Beijing 100084 China

An entanglement measure for multipartite pure states is formulated using the product of the von Neumann entropy of the reduced density matrices of the constituents. Based on this new measure, all possible ways of the maximal entanglement of the triqubit pure states are studied in detail and all types of the maximal entanglement have been compared with the result of ‘the average entropy’. The new measure can be used to calculate the degree of entanglement, and an improvement is given in the area near the zero entropy.

关键词： multipartite pure state von Neumann entropy entanglement measure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Constraints on smoothness parameter and dark energy using observational H(z) data

引用

Research in astronomy and Astrophysics 2011年第2期11卷 125-136页

作者： Hao-Ran Yu1,Tian Lan1,Hao-Yi Wan2,Tong-Jie Zhang1,3 and Bao-Quan Wang4.1 department of astronomy,Beijing Normal university,Beijing 100875,China 2 Business Office,Beijing Planetarium,Beijing 10004.,China 3 Center for High Energy Physics,Peking university,Beijing 100871,China 4.department of Physics,Dezhou university,Dezhou 253023,China department of astronomy Beijing Normal University Beijing 100875 China Business Office Beijing Planetarium Beijing 100044 China Center for High Energy Physics Peking University Beijing 100871 China department of Physics Dezhou University Dezhou 253023 China

With large-scale homogeneity,the universe is locally inhomogeneous,clustering into stars,galaxies and larger *** property is described by the smoothness parameter α which is defined as the proportion of matter in the form of intergalactic *** we consider the inhomogeneities over a small scale,there should be modifications of the cosmological distances compared to a homogenous *** and Roeder developed a second-order ordinary differential equation（D-R equation） that describes the angular diameter distance-redshift relation for inhomogeneous cosmological ***,we may obtain the D-R equation for observational H（z） data（OHD）.The density-parameter ΩM,the state of dark energy ω,and the smoothness-parameter α are constrained by a set of OHD in a spatially flat XCDM universe as well as a spatially flat XCDM *** using a χ2 minimization method,we get α = 0.81＋0.19-0.20 and ΩM = 0.32＋0.12-0.06 at the 1σ confidence *** we assume a Gaussian prior of ΩM = 0.26 ± 0.1,we get α = 0.93＋0.07-0.19 and ΩM = 0.31＋*** the XCDM model,α is constrained to α≥ 0.80 but ω is weakly constrained around-1,where ω describes the equation of state of the dark energy（pX = ωρX）.We conclude that OHD constrains the smoothness parameter more effectively than the data of SNe Ia and compact radio sources.

关键词： cosmology -- dark energy -- cosmological parameters

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Quantum threshold group signature

引用

Science China(Physics,Mechanics & astronomy) 2008年第10期51卷 1505-1514页

作者： YANG YuGuang1,2,3 & WEN QiaoYan4.1 College of Computer Science and Technology, Beijing university of Technology, Beijing 100124. China 2 state Key Laboratory of Integrated Services Network, Xidian university, Xi’an 710071, China 3 state Key Laboratory of Information Security (Graduate university of Chinese Academy of Sciences), Beijing 10004., China 4.state Key Laboratory of Networking and Switching Technology, Beijing university of Posts and Tele-communications, Beijing 100876, China College of Computer Science and Technology Beijing University of Technology Beijing 100124 China state Key Laboratory of Integrated Services Network Xidian University Xi’an 710071 China state Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences Beijing 100049 China state Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China

In most situations, the signer is generally a single person. However, when the message is written on behalf of an organization, a valid message may require the approval or consent of several persons. Threshold signature is a solution to this problem. Generally speaking, as an authority which can be trusted by all members does not exist, a threshold signature scheme without a trusted party appears more attractive. Following some ideas of the classical Shamir’s threshold signature scheme, a quantum threshold group signature one is proposed. In the proposed scheme, only t or more of n persons in the group can generate the group signature and any t-1 or fewer ones cannot do that. In the verification phase, any t or more of n signature receivers can verify the message and any t-1 or fewer receivers cannot verify the validity of the signature.

关键词： threshold quantum signature trusted party quantum cryptography

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：