检索结果-南通市图书馆

Recent beijing Spectroscopy (BES) results

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2008年第6期51卷 567-576页

作者： LI WeiGuo institute of high {2. physics, chinese academy of sciences, beijing 100049, China institute of high {2. physics Chinese Academy of Sciences Beijing China

Recent experimental results from beijing Spectroscopy (BES) are reviewed, including the hadron spectroscopy from J/ψ decays, and a number of new states are found or confirmed, including σ, κ, X(1835), ωφ threshold enhancement in J/ψ→γωφ, a broad resonance in J/ψ→K + K ? π 0, decay studies of ψ(2.) and χ CJ , as well as the results of ψ(3770) non-D $ \bar D $ decays. The current status of BEPCII/BESIII, the major upgrade of BEPC/BESII, is also reported.

关键词： beijing Spectroscopy hadron spectroscopy charm physics BEPCII

Studies on BEPC upgrade from pretzel to double-ring

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2010年第11期53卷 2084-2089页

作者： ZHANG Chuang institute of high {2. physics,chinese academy of sciences,beijing 100049,China chinese academy of sciences Institute of High Energy Physics Beijing China (GRID:grid.9227.e) (ISNI:***)

physics opportunity in the charm and τ energy region calls for {2.er luminosity of the beijing Electron-Positron Collider (BEPC).The BEPC has experienced continuous improvement since its completion in ***,as a major upgrading project of the BEPC,aims at enhancing its luminosity of factor 30–100,following the principle of "one machine,two purposes" as adopted in BEPC,so that both {2. energy physics and synchrotron radiation experiments can be carried out with *** the BEPC to BEPCII,the double-ring scheme with multi-bunch e +-e-collision in the large crossing angle was studied in comparison with the single-ring pretzel *** the dedicated synchrotron radiation operation,artful "bridges" are designed to connect two halves of the outer ring in both the southern and the northern crossing *** paper reviews the studies on the BEPC upgrade from pretzel to double-ring structure of BEPCII.

关键词： collider storage ring high energy physics synchrotron radiation

Geometry of Broad Line Regions of Active Galactic Nuclei

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Astronomy and Astrophysics 2008年第1期8卷 50-62页

作者： Xiao-Rong Lü1 Key Laboratory for Particle Astrophysics, institute of {2. energy physics, chinese academy of sciences, beijing 100049 2.Graduate School of chinese academy of sciences, beijing 100049 Key Laboratory for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 Graduate School of chinese academy of sciences Beijing 100049

It has long remained an open question as to the geometry of the broad line region （BLR） in active galactic nuclei （AGNs）. The reverberation mapping technique which measures the response of the broad emission lines to the ionizing continuum, when combined with multiwavelength continuum fitted by sophisticated accretion disks, provides a way of probing the BLR geometry. We analyze a sample of 35 AGNs, which have been monitored by the reverberation mapping campaign. In view of energy budget, the reverberation-based BH masses are found to be in agreement with those obtained by accretion disk models in two thirds of the present sample while the reverberation mapping methods underestimate the BH masses in about one third of objects, as also suggested by CoUin et al. in a recent work. We point out that there are obviously two kinds of BLR geometry, which are strongly dependent on the Eddington ratio, and separated by the value LBol/LEdd - 0.1. These results prefer a scenario of the disk and wind configuration of the BLR and identify the Eddington ratio as the physical driver regulating the wind in the BLR.

关键词： accretion, accretion disks - galaxies active - galaxies Seyfert - quasars general

The establishment of crystal position look-up table for positron emission tomography with block detectors

在线全文

学校读者我要写书评

暂无评论

Science China(Technological sciences) 2009年第8期52卷 2418-2423页

作者： CHAI Pei1,2.& SHAN BaoCi1 1 Key Laboratory of Nuclear Analytical Techniques, institute of high {2. physics, chinese academy of sciences, beijing 100049, China 2.Graduate University of chinese academy of sciences, beijing 100049, China Key Laboratory of Nuclear Analytical Techniques Institute of High Energy Physics Chinese Academy of Sciences Graduate University of chinese academy of sciences

A method has been developed to establish the crystal position look-up table for positron emission tomography with block detectors. It is based on the principle that the counts in crystal position histogram obey the Gaussian mixture model (GMM). This method has taken full consideration of the characteristics of the GMM and the detector itself. The experimental results have proved that it is simple, reliable, and universal.

关键词： positron emission tomography position look-up table 2.D position histogram

A 12.bit multichannel ADC for pixel detectors in particle physics and nuclear imaging

在线全文

学校读者我要写书评

暂无评论

Science China(Technological sciences) 2010年第5期53卷 1208-1214页

作者： WEI Wei1,2.3,WANG Zheng1,3 & ZHAO JingWei1,3 1 institute of {2. {2. physics,chinese academy of sciences,beijing 100049,China 2.Graduate University of chinese academy of sciences,beijing 100049,China 3 Key Lab of Nuclear Detection Technology and Nuclear Electronics of chinese academy of sciences,beijing 100049,China institute of high {2. physics Chinese Academy of Sciences Graduate University of chinese academy of sciences Key Lab of Nuclear Detection Technology and Nuclear Electronics of chinese academy of sciences

Modern pixel detectors in nuclear and particle physics experiments and also in nuclear imaging,starve for highly integrated application specified integrated circuit(ASIC),whereas in China the study of ASIC still stays far away from practical *** lack of ASIC strictly limits the research and development of domestic high energy physics field.A 12.bit multichannel ADC designed for high density readout is introduced as a major candidate for solution.A precise model is discussed and the simulation fully agrees with the model,which indicates a key principle of *** is performed according to the given rule,and novel layout techniques are carried *** results in all aspects are also obtained,showing an excellent real performance,which satisfies the practical requirement.

关键词： application specified integrated circuit high density readout Wilkinson ADC multi-channel ADC

Systematic distortion in cosmic microwave background maps

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2009年第5期52卷 804-808页

作者： LIU Hao 1,3 &LI TiPei 1,2.1Key Laboratory of Particle Astrophysics,institute of {2. energy physics,chinese academy of sciences,beijing 100049,China 2.enter for Astrophysics,Tsinghua University,beijing 100084,China 3 Graduate University of chinese academy of sciences,beijing 100049,China Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China Center for Astrophysics Tsinghua University Beijing China

To minimize instrumentally the induced systematic errors,cosmic microwave background(CMB)anisotropy experiments measure temperature differences across the sky using pairs of horn antennas, temperature map is recovered from temperature difference obtained in sky survey through a map-making *** inspect and calibrate residual systematic errors in the recovered temperature maps is important as most previous studies of cosmology are based on these *** analyzing pixel-ring coupling and latitude dependence of CMB temperatures,we find notable systematic devia- tion from CMB Gaussianity in released Wilkinson Microwave Anisotropy Probe(WMAP)*** detected deviation cannot be explained by the best-fit LCDM cosmological model at a confidence level above 99%and cannot be ignored for a precision cosmology study.

关键词： cosmology cosmic microwave background methods data analysis

Ashkin-Teller Formalism for Elastic Response of DNA Molecule to External Force and Torque

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2008年第2期49卷 525-528页

作者： CHANG Zhe~1 WANG Ping~(1,2. ZHENG Ying-Hong~(1,2. 1 institute of high {2. physics,the chinese academy of sciences,P.O.Box 918(4),beijing 100049,China 2.Graduate School,the chinese academy of sciences,beijing 100049,China institute of high {2. physics the Chinese Academy of Sciences P.O. Box 918(4) Beijing 100049 China Graduate School the Chinese Academy of Sciences Beijing 100049 China

We propose an Ashkin Teller-like model for elastic response of DNA molecule to external force and *** base-stacking interaction is described in a simple and uniform *** obtain the phase diagram of dsDNA,andin particular,the transition from B form to the S state induced by stretching and *** elastic response of thessDNA is presented also in a unified *** close relation of dsDNA molecule structure with elastic response isshown *** calculated folding angle of the dsDNA molecule is 59.2..

关键词： dsDNA elastic property

Narrow line Seyfert 1 galaxies: where are the broad line regions?

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2010年第12期53卷 2307-2311,2339-2343页

作者： MAO WeiMing 1,2.3 , HU Chen 2., WANG JianMin 2., BIAN WeiHao 4 , ZHANG Shu 2.& ZHAO Gang 1 1 Key Laboratory of Optical Astronomy, National Astronomical Observatories, chinese academy of sciences, {2. 100012. China 2.Key Laboratory for Particle Astro{2., institute of high energy {2., chinese academy of sciences, beijing 100049, China 3 Graduate University of the chinese academy of sciences, beijing 100049, China 4 Department of {2., Nanjing Normal University, Nanjing 2.0011, China chinese academy of sciences Key Laboratory of Optical Astronomy National Astronomical Observatories Beijing China (GRID:grid.9227.e) (ISNI:***) chinese academy of sciences Key Laboratory for Particle Astrophysics Institute of High Energy Physics Beijing China (GRID:grid.9227.e) (ISNI:***) Graduate University of the chinese academy of sciences Beijing China (GRID:grid.458514.9) chinese academy of sciences Key Laboratory for Particle Astrophysics Institute of High Energy Physics Beijing China (GRID:grid.9227.e) (ISNI:***) Nanjing Normal University Department of Physics Nanjing China (GRID:grid.260474.3) (ISNI:***) chinese academy of sciences Key Laboratory of Optical Astronomy National Astronomical Observatories Beijing China (GRID:grid.9227.e) (ISNI:***)

A sample consisting of 2.1 narrow line Seyfert 1 galaxies (NLS1s) with high quality spectra from the Sloan Digital Sky Survey (SDSS) is selected to explore where broad line regions are in these objects. We find that the Hβ profile can be fitted well by three (narrow, intermediate and broad) Gaussian components, and the FWHM ratios of the broad to the intermediate components hold a constant of 3.0 roughly for the entire sample. If the broad components originate from the region scaled by the well-determined Hβ reverberation mapping relation, we find that the intermediate components originate from the inner edge of the torus, which is scaled by dust K-band reverberation. We find that the IC and the BC are strongly linked dynamically, but the relation of their covering factors is much more relaxed, implying that both regions are clumpy.

关键词： black hole physics galaxies: evolution quasars: general

The principle of relativity, kinematics and algebraic relations

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2010年第4期53卷 591-597页

作者： GUO HanYing1, HUANG ChaoGuang2.3, WU HongTu4 & ZHOU Bin5 1institute of Theoretical {2., {2., beijing 100190, China 2.1} of high energy {2., {2., beijing 100049, China 3Theoretical {2. Center for Science Facilities, {2., beijing 100049, China 4Department of Mathematics, Capital Normal University, beijing 100048, China 5Department of {2., beijing Normal University, beijing 100875, China chinese academy of sciences Institute of Theoretical Physics Beijing China (GRID:grid.9227.e) (ISNI:***) chinese academy of sciences Institute of High Energy Physics Beijing China (GRID:grid.9227.e) (ISNI:***) chinese academy of sciences Theoretical Physics Center for Science Facilities Beijing China (GRID:grid.9227.e) (ISNI:***) Capital Normal University Department of Mathematics Beijing China (GRID:grid.253663.7) (ISNI:***) beijing Normal University Department of Physics Beijing China (GRID:grid.20513.35) (ISNI:***)

Based on the relativistic principle and the postulate of universal invariant constants (c, l), all kinematic symmetries can be set up as the subsets of the Umov-Weyl-Fock-Hua transformations for the inertial motions. ... 详细信息

关键词： principle of relativity with (c l) Umov-Weyl-Fock-Hua transformations kinematics special relativity triple