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| 1 | Pseudo-dipole signal removal from WMAP data显示文摘We have discovered in our previous work that different observational systematics,e.g.errors from antenna pointing directions or an asynchronism between the attitude and science data may generate a pseudo-dipole signal in the full-sky maps of the cosmic microwave background (CMB) anisotropy that have been published by the Wilkinson Microwave Anisotropy Probe (WMAP) team.We have found that the antenna sidelobe response to the Doppler signal produces a similar effect.In this work,independent from the sources,we have uniformly modeled the pseudo-dipole signal and have removed it from the published WMAP7 CMB maps by model fitting.The result demonstrates that the released WMAP CMB quadrupole is almost completely artificial. | LIU Hao LI TiPei | 2011 | Chinese Science Bulletin2011，56，1： | 6 |
| 2 | 星载合成孔径雷达高精度快速定位方法显示文摘星载合成孔径雷达(SAR)定位是其影像应用的基础,研究高效能的定位方法对促进SAR影像应用具有重要意义.从SAR成像机理出发,分析揭示了SAR成像几何的两个基本特性,并对两个特性的合理性进行了论证.基于此,提出了一种高精度快速定位解算方法.针对目前国际上最为典型的四种SAR卫星,德国TerraSAR-X、意大利COSMO-SkyMed、日本ALOS-PalSAR和加拿大Radarsat-2进行了精度分析,结果表明本文方法的精度完全能够满足这四种卫星的实际需求.最后,利用TerraSAR-X聚束模式SAR实测数据进行快速定位处理,性能评估结果表明在极大降低运算量的情况下保持了极高的定位精度,验证了方法的高效性和正确性. | 王青松 黄海风 董臻 余安喜 何峰 梁甸农 | 2011 | 科学通报2011，56，31： | 4 |
| 3 | 宇宙微波背景辐射对量子卫星信道性能及纠缠储备量的影响显示文摘2016年8月16日1时40分,我国长征二号运载火箭成功将世界首颗量子科学实验卫星'墨子号'发射升空。然而,有关宇宙微波背景辐射(Cosmic Microwave Background radiation,简称CMB)对量子卫星信道通信性能及纠缠储备量影响的研究,至今尚未展开。为此,本文根据CMB辐射谱与黑体辐射谱完美的拟合特性和小尺度范围内的各向异性,得到CMB绝对温度、辐射波长和黑体辐出度的关系。针对幅值阻尼信道,建立了CMB绝对温度、黑体辐出度、辐射波长、信道平均保真度和纠缠度之间的定量关系。仿真结果表明,当CMB绝对温度为2.7K和3.0K时,黑体辐出度分别为0.03 W·μm和3.72 W·μm,量子卫星信道的平均保真度和纠缠度分别为0.64、0.43和0.41、0.12。由此可见,CMB对量子卫星信道通信性能的影响极大。因此,在实际的量子卫星通信系统中,应根据不同的CMB绝对温度,自适应调节算符纠缠的幺正操作,改变信道的纠缠储备量,使信道纠缠度维持在相对稳定的状态,降低CMB对卫星信道通信性能的影响。 | 贾娜 聂敏 杨光 张美玲 裴昌幸 | 2017 | 量子光学学报2017，23，2： | 4 |
| 4 | High-precision,fast geolocation method for spaceborne synthetic aperture radar显示文摘Geolocation using spaceborne synthetic aperture radar(SAR) is essential for imagery applications,and high performance geolocation methods need to be developed to promote SAR imagery applications.Starting from the SAR imaging principle,this paper reveals and analyzes two basic characteristics of SAR imaging geometry,and demonstrates the rationality of the two characteristics.On this basis,a high-precision and fast geolocation method is proposed.We conducted a precision analysis on four SAR satellites(Germany's TerraSAR-X,Italy's COSMO-SkyMed,Japan's ALOS-PalSAR and Canada's Radarsat-2 satellites),and the results show that the precision of the proposed method meets practical needs.We then used TerraSAR-X SpotLight SAR real data to implement the fast geolocation,and found from performance evaluation that the computation cost is greatly reduced while high geolocation accuracy is maintained.We thus verified the efficiency and accuracy of the proposed method. | WANG QingSong HUANG HaiFeng DONG Zhen YU AnXi HE Feng LIANG DianNong | 2012 | Chinese Science Bulletin2012，57，2： | 1 |
| 5 | Some recent progress in study of gravity and cosmology显示文摘We briefly review some progress made in the areas of gravity and cosmology.Only a small portion of the work done in China is covered. | LI Miao | 2012 | Chinese Science Bulletin2012，57，36： | 0 |
| 6 | Design of Experimental Data Publishing Software for Neutral Beam Injector on EAST显示文摘Neutral Beam Injection(NBI) is one of the most effective means for plasma heating.Experimental Data Publishing Software(EDPS) is developed to publish experimental data to get the NBI system under remote monitoring.In this paper,the architecture and implementation of EDPS including the design of the communication module and web page display module are presented.EDPS is developed based on the Browser/Server(B/S) model,and works under the Linux operating system.Using the data source and communication mechanism of the NBI Control System(NBICS),EDPS publishes experimental data on the Internet. | 张睿 胡纯栋 盛鹏 赵远哲 张晓丹 吴德云 | 2015 | Plasma Science and Technology2015，17，2： | 0 |
| 7 | Is the possible fine-structure constant drift also a test of a time-dependent Planck constant?显示文摘The recent publication of spatial and distance variation of the fine-structure constant, α, derived from astronomical data of quasar emissions (QE) is exciting. The decreasing value of α over time, derived from data obtained from the Very Large Telescope (VLT) in Chile, encourages the search for other possible running constants. We surmise that emissions from distant supernovae, type Ia (SNe Ia), which are more blue than predictions are best explained by a decreasing Planck constant with increasing lookback time. We present some results from our theoretical work and comparison to the astronomical observations and suggest that both α and h might be running constants. More data are required to answer several questions about the origin of the 'drifting' α and the possible time dependence of h. Astronomical tools such as SNe and QE may be the best means to secure the exacting data needed to confirm or deny these hypotheses. | ZTAS A. M. SMITH M. L. | 2011 | Science China(Physics,Mechanics & Astronomy)2011，54，12： | 0 |
| 8 | 微波背景观测与早期宇宙研究显示文摘微波背景观测与早期宇宙研究尚处于学科发展的初期阶段,对探测方法、背景(前景)处理、系统误差及结果可靠性的认识都有待深入.发现微波探测卫星WMAP公布的宇宙微波背景辐射温度图存在严重的系统误差后,几年来我们重新进行了数据分析,修正了时钟同步、天线旁瓣误差导致的伪偶极信号,得到的背景辐射温度图和功率谱与WMAP发布的结果有重大差异,引起了广泛关注,讨论和争论.本文概述有关工作及论争的过程与现状,及其对于早期宇宙研究的影响. | 李惕碚 | 2011 | 中国科学:物理学、力学、天文学2011，41，4： | 0 |
| 9 | 清华大学天体物理学科介绍显示文摘简要介绍清华大学天文学科发展的历史以及清华大学天体物理中心目前的研究方向及主要的成绩.这些研究主要包括:卫星载带硬X射线调制望远镜的研究,高能天体物理的研究,光学波段的天文观测与研究,宇宙学的研究,引力波观测数据的分析与处理以及理论天体物理的研究. | 陶嘉琳 尚仁成 | 2011 | 中国科学:物理学、力学、天文学2011，41，4： | 0 |
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