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

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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 high energy 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 1. institute of high energy physics Chinese Academy of Sciences Beijing 100049 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Key Lab of Nuclear Detection Technology and Nuclear Electronics of Chinese Academy of Sciences Beijing 100049 China

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

Formation of super-concentrated hydrochloric acid in the third phase in tertiary amine N235-PtCl_6^(2-)-HCl system and its influences on the Pt microemulsion extraction

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Science china Chemistry 2009年第11期52卷 1825-1834页

作者： HUANG Kun1,CHEN Jing1,ZHANG ChengFeng1,2,LI ZhiHong3,PAN QingHua1,SUN Yan1,LIU ShaoXuan1,LIU XueXin2,LI WeiHong1,YANG ZhanLan1,WENG ShiFu1,HU TianDou3,XU YiZhuang1 & WU JinGuang1 1 College of Chemistry and Molecular Engineering,Peking University,beijing 100871,china 2 institute of Chemistry,chinese academy of sciences,beijing 100190,china 3 institute of high energy physics,chinese academy of sciences,beijing 100049,china 1. College of Chemistry and Molecular Engineering Peking University Beijing 100871 China 2. institute of Chemistry Chinese Academy of Sciences Beijing 100190 China 3. institute of high energy physics Chinese Academy of Sciences Beijing 100049 China

In this paper,we have investigated the formation of the third-phase in tertiary amine(N235)-PtCl62--HCl system and the microscopic phase structural evolution of platinum-loaded organic phases before and after the occurrence of the *** third-phase is characterized by various spectroscopic techniques,and the small angle X-ray scattering(SAXS) experiments demonstrate the appearance of nano-aggregates,i.e.,water-in-oil reversed micelles,in the third *** experimental results indicate that(1) formation of the third phase is related to the aggregation behaviors of nano-reversed micelles in which a super-concentrated hydrochloric acid formed with the H+ to H2O molar ratio being much higher than that of the conventional 37 wt% saturated hydrochloric acid.(2) The occurrence of the super-concentrated HCl results in a great amount of H+ and Cl-ions enriched and confined within the nano-water pools of W/O reversed micelles in third ***,the coordination behaviors of platinum complex ions in that super-concentrated hydrochloric acid are very different from their corresponding behaviors in bulk aqueous *** is possible that H+ ions participate in the formation of such complexes as HmPtCl6z+ in the super-concentrated hydrochloric acid.(3) The relative contents of various HmPtCl6z+ complexes are different corresponding to the H+ ion concentrations in confined nanowater *** association ability of the acidified tertiary amine N235 molecules(R3NH+) with various HmPtCl6z+ complexes plays an important role in affecting the platinum extraction behaviors.

关键词： solvent extraction third phase super-concentrated hydrochloric acid tertiary amine platinum

Simulation study of real-time monitor for BEPC-Ⅱ luminosity

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Science china(Technological sciences) 2010年第5期53卷 1215-1219页

作者： SHAN Qing1,2,WU Jian2,XUE Zhen2,XU ZiZong2,HU Tao3,WANG YiFang3 & WANG XiaoLian2 1 College of Material Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,china 2 Department of Modern physics,University of Science and Technology of china,Hefei 230026,china 3 institute of high energy physics,chinese academy of sciences,beijing 100049,china College of Material Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing China Department of Modern physics University of Science and Technology of China Hefei China institute of high energy physics Chinese Academy of Sciences Beijing China

A fast and real time luminosity monitor system will be used in the BEPC-Ⅱ(beijing Electron Positron Collider,china).Photons generated in radiative Bhabha scattering at the interaction point are transformed into charged particles,and then the luminosity of each bunch pair is measured through collecting the Cherenkov light produced by charged particles in fused *** whole process happening in the detector is *** physics acceptance and detection threshold with the monitor accu-racy of 1% are set based on the simulation spectra of photoelectron yield calibrated by e-beam data.

关键词： luminosity BEPC-Ⅱ Cherenkov detector radiative Bhabha

Ratio of Real to Imaginary for pp and p Elastic Scatterings in QCD Inspired Model

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Communications in Theoretical physics 2007年第3期 550-554页

作者： LU Juan~(1,2) MA Wei-Xing~(1,3) HE Xiao-Rong~21 Collaboration Group of Hadron physics and Non-perturbative QCD Study,Guangxi University of Technology,Liuzhou545006,china2 institute of physics Science and Engineering Technology,Guangxi University,Nanning 530004,china3 institute of high energy physics,the chinese academy of sciences,beijing 100049,china Collaboration Group of Hadron physics and Non-perturbative QCD Study，Guangxi University of Technology，Liuzhou 545006，china institute of physics Science and Engineering Technology，Guangxi University，Nanning 530004，china Collaboration Group of Hadron physics and Non-perturbative QCD Study，Guangxi University of Technology，Liuzhou 545006，china institute of high energy physics，the chinese academy of sciences，beijing 100049，china institute of physics Science and Engineering Technology，Guangxi University，Nanning 530004，china

We use the QCD inspired model to analyze the ratio of the real to the imaginary for pp and p;p elasticseatterings.A calculation for the ratio of the real to the imaginary is performed in which the contributions from gluon-gluon interaction,quark-quark interaction,quark-gluon interaction,and odd eikonal profile function are *** show that the QCD inspired model gives a good fit to the LHC experimental data.

关键词： QCD inspired model eikonal profile function ratio of real to imaginary

一种基于半马尔可夫网络流量模型的延迟估计算法(英文)

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系统仿真学报 2008年第19期20卷 5053-5057,5061页

作者：朱灵波戴冠中 LIN-SHI Xue-fang RETIF Jean-Marie 任维娟西北工业大学自动化学院陕西西安710072 法国国立里昂应用科学学院安培实验室法国维尔巴纳市69621 中国科学院高能物理研究所北京100049

提出一种基于半马尔可夫网络流量模型的延迟估计算法,用于估计传输链路的延迟超过某个阈值的概率,该值可做为控制器设计及控制策略选择的依据。利用半马尔可夫理论对网络流量进行建模,建立了延迟与网络传输中的队列队长、及队长与网络... 详细信息

提出一种基于半马尔可夫网络流量模型的延迟估计算法,用于估计传输链路的延迟超过某个阈值的概率,该值可做为控制器设计及控制策略选择的依据。利用半马尔可夫理论对网络流量进行建模,建立了延迟与网络传输中的队列队长、及队长与网络流速率的函数关系,之后经过推导和有限分割,得出网络延迟概率计算公式,并分析了该算法的复杂度。在计算布朗运动积分时采用It积分实现。仿真证明该算法是有效、可行的。

关键词：延迟估计半马尔可夫模型网络化控制系统布朗运动 Ito积分

Recent beijing Spectroscopy (BES) results

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

作者： LI WeiGuo institute of high energy physics, chinese academy of sciences, beijing 100049, china 1. institute of high energy physics Chinese Academy of Sciences Beijing 100049 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(2S) 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

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

作者： ZHANG Chuang institute of high energy physics,chinese academy of sciences,beijing 100049,china 1. institute of high energy physics Chinese Academy of Sciences Beijing 100049 China

physics opportunity in the charm and τ energy region calls for higher 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 high 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

Effects of cosmological constant on motion of UHECR particles

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Science china(physics,Mechanics & Astronomy) 2005年第1期48卷 44-56页

作者： CHEN Shaoxia & CHANG Zhe institute of high energy physics, chinese academy of sciences, beijing 100039, china Graduate School of chinese academy of sciences, beijing 100039, china institute of high energy physics Chinese Academy of Sciences Beijing 100039 China Graduate School Chinese Academy of Sciences Beijing 100039 China

Recent astronomical observations manifest that about two-thirds of the whole energy in the Universe is contributed by a small positive cosmological constant A (> 0). Then, an asymptotically de Sitter spacetime is premised naturally. However, physics in the de Sitter spacetime is very different from that in the Minkowski spacetime. As the first step, a covariant formalism of the kinematics in the de Sitter spacetime is presented here. By solving exactly the equations of motion for a field, we obtain the dispersion relation of a free particle. It is noticed that the dispersion relation is dependent on the degree of freedom of angular momentum of the particle. We show the threshold anomaly of the ultra high energy cosmic ray disappears naturally in the framework of the de Sitter kinematics.

关键词： ultrahigh energy cosmic ray, cosmological constant, curved spacetime.

Geometry of Broad Line Regions of Active Galactic Nuclei

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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 high 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 and 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