检索结果-南通市图书馆

Comparison of dark energy models:A perspective from the latest observational data

中国科学：物理学、力学、天文学英文版 2010年第9期53卷 1631-1645页

作者： LI Miao1,2.LI XiaoDong2.3.& ZHANG Xin1,4 1Kavli Institute for Theoretical physics {2.,chinese Academy of sciences,beijing 100190,{2. 2.ey Laboratory of Frontiers in Theoretical physics,Institute of Theoretical physics,chinese Academy of sciences,beijing 100190,{2. 3.nterdisciplinary Center for Theoretical Study,University of Science and Technology of {2.,Hefei 2.002.,{2. 4Department of physics,College of sciences,Northeastern University,Shenyang 110004,{2. 1. Kavli Institute for Theoretical physics china Chinese Academy of Sciences Beijing 100190 China2. Key Laboratory of Frontiers in Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China3. Interdisciplinary Center for Theoretical Study University of Science and Technology of China Hefei 230026 China4. Department of Physics College of Sciences Northeastern University Shenyang 110004 China

We compare some popular dark energy models under the assumption of a flat universe by using the latest observational data including the type Ia supernovae Constitution compilation,the baryon acoustic oscillation measurement from the Sloan Digital Sky Survey,the cosmic microwave background measurement given by the seven-year Wilkinson Microwave Anisotropy Probe observations and the determination of H0 from the Hubble Space *** comparison statistics such as the Bayesian and Akaike information criteria are applied to assess the worth of the *** statistics favor models that give a good fit with fewer *** on this analysis,we find that the simplest cosmological constant model that has only one free parameter is still preferred by the current *** other dynamical dark energy models,we find that some of them,such as the αdark energy,constant w,generalized Chaplygin gas,Chevalliear-Polarski-Linder parametrization,and holographic dark energy models,can provide good fits to the current data,and three of them,namely,the Ricci dark energy,agegraphic dark energy,and Dvali-Gabadadze-Porrati models,are clearly disfavored by the data.

关键词： dark energy models observational constraints model comparison information criteria

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

Potential land for plantation of Jatropha curcas as feedstocks for biodiesel in china

引用

Science china Earth sciences 2010年第1期53卷 120-127页

作者： WU WeiGuang 1,2.3,HUANG JiKun 1,3.& DENG XiangZheng 1,3.1 Institute of Geographic sciences and Natural Resources Research,{2. Academy of sciences,beijing 100101,china 2.Department of Economics and Management,Zhejiang Forestry University,Linan 3.13.0,china 3.Center for {2. Agricultural Policy,{2. Academy of sciences,beijing 100101,china 1. Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China2. Department of Economics and Management Zhejiang Forestry University Linan 311300 China3. Center for Chinese Agricultural Policy Chinese Academy of Sciences Beijing 100101 China

As a renewable energy,biofuel has attracted great attention in china and the rest of *** with the national food security,china recently has shifted its biofuel development priority from grain-based to non-grain-based biofuels,including forest-based biodiesel,since *** curcas is one of major biodiesel ***,there is rising debate on availability of land for expanding Jatropha curcas *** overall goal of this paper is to evaluate potential land for Jatropha curcas used as feedstock for biodiesel in *** on remote sensing data on land use,data on meteorological,soil and land slope,and suitable environment for Jatropha curcas plantation,this study uses Agro Ecological Zone method and considers social-economic constraints to evaluate potential suitable land for Jatropha curcas plantation in china's major Jatropha curcas production region,Southwest *** results show that while there are some potential lands to expand Jatropha curcas areas,amount of these lands will hardly meet the government's target for Jatropha curcas-based biodiesels development in the *** may need to reconsider its long-term targets on the development of Jatropha curcas-based biodiesels.

关键词： biodiesel Jatropha curcas potential land suitability evaluation Southwest china

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

Time of impact of fragment P2.of comet SL 9 on Jupiter

引用

chinese Science Bulletin 1997年第5期42卷 396-398页

作者： ZHOU Hongnan,QIAN Bochen, HUANG Keliang and LI Qibin1. Department of Astronomy, Nanjing University, Nanjing 2.0093. china 2. Shanghai Observatory, {3. Academy of {2., Shanghai 2.003., china 3. physics Department, Nanjing Normal University, Nanjing 2.0097, china 4. beijing Astronomical Observatory, {3. Academy of {2., beijing 100080, china Department of Astronomy Nanjing University Nanjing China Shanghai Observatory Chinese Academy of Sciences Shanghai China physics Department Nanjing Normal University Nanjing China beijing Astronomical Observatory Chinese Academy of Sciences Behijing China

FROM 1994-07-16 to 1994-07-2., 2. fragments of comet SL 9 impacted against Jupiter in succession. During the impact period the impact of fragments D, E, K, N, P2.and S was observed in {3.. We used a 1.56-m telescope with the CCD camera of Shanghai Observatory to monitor Jupiter and its Galilean Satellites, obtaining 1000 high-quality images at B, V, I wave bands. Our data on optical wave bands are rather complete and valuable in the world. Specially, we got some images of Jupiter, Io and Europa in the impact time of fragment P2.impacting against Jupiter. This will help us understand the precise time, position, depth and {2. of the P2.s collision. In this note, we report the impact time of fragment P2.of comet SL 9 and Jupiter. Since the impact of comet SL 9 was expected to take place on the side of Jupiter

关键词： comet comet Shoemaker-Levy 9 impacting against Jupiter impact time.

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

The rms-flux relation of Cyg X-2.in the horizontal branch

引用

中国科学：物理学、力学、天文学英文版 2010年第S1期53卷 86-90页

作者： LI ZhiBing,LEI YaJuan,QU JinLu,ZHANG Shu & SONG LiMing Key Laboratory for Particle Astrophysics,Institute of high {2. physics,chinese Academy of sciences(CAS),beijing 100049,china chinese Acad Sci Inst High Energy Phys Key Lab Particle Astrophys Beijing 100049 Peoples R China

We have investigated the relation between the root mean square(rms) variability and the X-ray flux(rms-flux relation) of the Z source Cyg X-2.and as well the energy dependence based on the Rossi X-ray Timing Explorer(RXTE) *** currently focus on the horizontal branch(HB),due to the negative correlation in flux of the soft and the hard *** rms-flux correlation has energy dependence as follows:positive at hard X-rays(above 10 keV) but negative at soft X-rays(below 10 keV).This provides a feature different from the previous one,and may be suggestive of different origins of X-rays below and above 10 ***,the overall spectrum can be well fitted with a model consisting of a blackbody and Comptonization components,but the fitting results do not reveal any features around 10 keV that could account for such a change in the rms-flux relation.

关键词： accretion accretion disk—binaries:close-stars:individual(Cygnus X-2.-X-rays:binaries

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

De-interlacing technique based on total variation with spatial-temporal smoothness constraint

引用

Science in china(Series F) 2007年第4期50卷 561-575页

作者： YIN XueMin1,2.3, YUAN JianHua1,2. LU XiaoPeng1,2.& {3. MouYan1,2.1 Institute of Electronics, {2. Academy of sciences, beijing 100080, china 2.Graduate School, {2. Academy of sciences, beijing 10003., china 3.Jiuquan Satellite Launch Center, Lanzhou 73.1}50, china 1. Institute of Electronics Chinese Academy of Sciences Beijing 100080 China 2. Graduate School Chinese Academy of Sciences Beijing 100039 China 3. Jiuquan Satellite Launch Center Lanzhou 732750 China

This paper introduces a new method of converting interlaced video to a progressively scanned video and image, The new method is derived from Bayesian framework with the spatial-temporal smoothness constraint and the MAP is done by minimizing the energy functional, The half-quadratic regularization method is used to solve the corresponding partial differential equations （PDEs）, This approach gives the improved results over the conventional de-interlacing methods, Two criteria are proposed in the paper, and they can be used to evaluate the performance of the de-interlacing algorithms,

关键词： video processing de-interlacing total variation spatio-temporai smoothness constraint PDEs half-quadratic regularization

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

Design of Robust Var Reserve Contract for Enhancing Reactive Power Ancillary Service Market Efficiency

引用

CSEE Journal of Power and energy Systems 2024年第2期10卷 767-771页

作者： Yunyang zou Yan Xu School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore 639798Singapore

In a deregulated Var market, market power issue is more serious than in an energy market since reactive power cannot be transmitted over long distances. This letter designs a multi-timescale Var market framework, where market power that may arise in the hourly-ahead Var support service market due to system configuration deficiency and market structure flaws can be eliminated by day-ahead contract-based Var reserve service market. Settlement of day-ahead Var reserve contract is formulated as a two-stage robust optimization (TSRO) model considering worst case of uncertainty realization and potential market power that may arise in hourly-ahead market. TSRO with integer recourses is then solved by a new column and constraint generation algorithm. Results show a robust Var reserve contract can fully eliminate market power, and prevent suppliers from manipulating market prices.

关键词： Market efficiency market power reactive power ancillary service two-stage robust optimization Var reserve

来源：

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

Observation of signature inversion in the πh_(9/2.(×)νi_(13.2. oblate band

引用

Science china(physics,Mechanics & Astronomy) 2005年第4期48卷 442-449页

作者： XIE Chengying1,2. ZHOU Xiaohong1,2. ZHANG Yuhu1, GUO Yingxiang1, LEI Xiangguo1, ZHENG Yong1, LIU Minliang1, SONG Litao1, WANG Hualei1, YU Haiping1, GUO Wentao 1, LUO Peng1, WU Zhijun1, ZHU Lihua3.& WU Xiaoguang3.⒈ Institute of Modern physics, {3. Academy of {2., Lanzhou 73.000, china ⒉ Graduate School of the {3. Academy of {2., beijing 100049, china ⒊ Institute of Atomic energy Research, beijing 102.13. china Institute of Modern physics Chinese Academy of Sciences Lanzhou China Graduate School of the chinese Academy of sciences Beijing China Institute of Atomic energy Research Beijing China

high-spin states in 190Tl have been studied via the 160Gd(3.Cl, 5nγ) reaction. The level scheme, consisting of the π h9 /2. νi13.2.oblate band and a cascade with character of single particle excitations, has been established. Spin values have been firmly assigned to the oblate band in 190Tl, resulting in low-spin signature inversion in the π h9 /2. νi13.2.oblate band for the first time. Based on the similarity of the level structure in doubly odd Tl nuclei, spin values for the oblate bands in 192.2.0Tl should be re-assigned, and a consistent low-spin signature inversion has occurred in these oblate deformed nuclei. The low-spin signature inversion phenomena can be interpreted qualitatively by using the 2.quasiparticle plus rotor model including p-n residual interactions.

关键词： deformed odd-odd 190Tl, oblate rotational bands, signature inversion, 2.qp+rotor model.

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

Calibrating the HXMT collimators using diffuse illumination

引用

Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 36-39页

作者： HAN Dong1,JIN YongJie1,WU Mei2.& ZHANG Zhi1 1 Department of Engineering physics & Center for Astrophysics,Tsinghua University,{2. 100084,china 2.Key Laboratory of Particle Astrophysics,Institute of high energy physics,chinese Academy of sciences,beijing 100049,china 1. Department of Engineering physics & Center for Astrophysics Tsinghua University Beijing 100084 China 2. Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

We propose a new method to calibrate the HXMT collimators by measuring the optical point spread function(PSF) of the hard X-ray modulation telescope(HXMT).The light transmission of the collimator at different viewing angles with a camera and a diffuse backlight placed behind the collimator is *** method is much easier to accomplish than measuring the PSF with a parallel optical *** experimental results are very consistent with the *** PSF of the collimator of the high energy X-ray telescope on HXMT is found to be in good agreement with the design,with accuracy better than 1 arcmin.

关键词： HXMT collimator point spread function Monte Carlo simulation diffuse illumination

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

Timing in the Time Domain: Cygnus X-1

引用

chinese Journal of Astronomy and Astrophysics 2001年第4期1卷 313-332页

作者： Ti-Pei Li (Department of physics and Center for Astrophysics, Tsinghua University, {2. 100084 {3. energy Astrophysics Lab., Institute of {3. energy physics, chinese Academy of sciences, {2. 10003.)E-mail:litp@*** Department of physics and Center for Astrophysics Tsinghua University Beijing 100084 High Energy Astrophysics Lab. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100039

Quantities characterizing temporal property, e.g., power density, coherence, and time lag, can be defined and calculated directly in the time domain without using the Fourier transformation. Spectral hardness, variability duration, and correlation between different characteristic quamtities on different time scale can be studied in the time domain as well. The temporal analysis technique in the time domain is a powerful tool, particularly in studying rapid variability on short time scales (or in high frequencies). Results of studying variabilities of X-rays from Cyg X-1 with the analysis technique in the time domain and RXTE data reveal valuable clues to understanding production and propagation processes of X-rays and structure of accretion disk in the black hole system.

关键词： methods: data analysis - stars: individual (Cygnus X-1) - X-rays: stars

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

PIXE and INAA studies on ancient potteries from Guangfulin relics in Shanghai

引用

Progress in Natural Science:Materials International 2007年第11期17卷 1348-1356页

作者： Lin Jiawei1, Cheng Huansheng1, Zhang Zhengquan1, Zhang Bin1, Feng Songlin2. Song Jian3. Gao Menghe4 and Zhu Dan1(1. Applied Ion Beam physics Laboratory, Key Laboratory of the Ministry of Education, Institute of Modern physics, Fudan University, Shanghai 2.043., {2. 2. Key Laboratory of Nuclear Analytical Techniques, Institute of high energy physics, beijing 10003., {2. 3. Shanghai Museum, Shanghai 2.0003. {2. 4. Department of Cultural Heritage and Museology, Fudan University, Shanghai 2.043., {2.) Applied Ion Beam physics Laboratory Key Laboratory of the Ministry of Education Institute of Modern Physics Fudan University Shanghai 200433 China Key Laboratory of Nuclear Analytical Techniques Institute of High Energy Physics Beijing 100039 China Shanghai Museum Shanghai 200003 China Department of Cultural Heritage and Museology Fudan University Shanghai 200433 China

This paper reports the study of ancient potteries unearthed from the Guangfulin site in Shanghai. From the external features of these potteries, archeologists can classify them into two different cultural types: Liangzhu culture (local culture) and a new culture which might be derived elsewhere, but they can not recognize whether they were produced in the same place. Proton induced X-ray emission (PIXE) and instrumental neutron activation analysis (INAA) were used to measure the chemical compositions of the samples and the results were analyzed using multivariate statistics. We found that the two methods can complement each other and their database can be mutually referenced in the study of ancient potteries. Experimental results show that the compositions of the potteries from the two cultural types are different, which means that the materials for ancient potteries of new culture originate from elsewhere. This supports the archaeologists’ speculation that a group of ancient people migrated to Shanghai from some other places 4000 years ago.

关键词： PIXE INAA factor analysis Guangfulin ancient pottery

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

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：