Publications (16)17.78 Total impact
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Article: Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter
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ABSTRACT: Ensuring the radiation hardness of PbWO4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered. Comment: 24 pages, 19 figures, available on CMS information server at http://cms.cern.ch/iCMS/12/2009; -
Article: The CMS experiment at the CERN LHC
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ABSTRACT: The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 1034 cm−2 s−1 (1027 cm−2 s−1). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4π solid angle. Forward sampling calorimeters extend the pseudorapidity coverage to high values (|η| ≤ 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t.Journal of Instrumentation 08/2008; 3(08):S08004. · 1.87 Impact Factor -
Article: Synthesis and biological evaluation of substituted phenylpyrazole[4,5-b]oleanane derivatives as inhibitors of glycogen phosphorylase.
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ABSTRACT: A series of substituted phenylpyrazole[4,5-b]oleanane derivatives have been synthesized and biologically evaluated as inhibitors of glycogen phosphorylase (GP). The structure of phenylpyrazole moiety in compound 17 was determined by ROESY. All of the synthesized oleanane derivatives were biologically evaluated against rabbit muscle GPa. Within this series of compounds, pyrazole triterpene 7 (IC(50) = 10.8 μM) exhibited slightly more potent activity than its parent compound 1. Preliminary SAR analysis of the pyrazoleoleanane derivatives as GP inhibitors is discussed.Drug discoveries & therapeutics. 04/2008; 2(2):115-21. -
Article: Reconstruction of the signal amplitude of the CMS electromagnetic calorimeter
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ABSTRACT: The amplitude of the signal collected from the PbWO4 crystals of the CMS electromagnetic calorimeter is reconstructed by a digital filtering technique. The amplitude reconstruction has been studied with test beam data recorded from a fully equipped barrel supermodule. Issues specific to data taken in the test beam are investigated, and the implementation of the method for CMS data taking is discussed.European Physical Journal C 06/2006; 46:23-35. · 3.63 Impact Factor -
Article: Results of the first performance tests * of the CMS electromagnetic calorimeter
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ABSTRACT: Performance tests of some aspects of the CMS ECAL were carried out on modules of the "barrel" sub-system in 2002 and 2003. A brief test with high energy electron beams was made in late 2003 to validate prototypes of the new Very Front End electronics. The final versions of the monitoring and cooling systems, and of the high and low voltage regulation were used in these tests. The results are consistent with the performance targets including those for noise and overall energy resolution, required to fulfil the physics programme of CMS at the LHC.European Physical Journal C 12/2005; 44:1-10. · 3.63 Impact Factor -
Article: Fe 3O 4 nanowire arrays synthesized in AAO templates
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ABSTRACT: Fe3O4 nanowire arrays with an average diameter of about 120nm and lengths up to 8m were synthesized in anodic aluminum oxide templates through electrodepositing and heat treating a precursor -FeOOH. The nanowires have a polycrystalline spinel structure with a=8.31 and each nanowire is composed of fine particles. Influences of the sintering and the reducing temperatures on the products have been demonstrated by Mssbauer spectra and X-ray diffraction. It was found that high-coercivity nanowires can be obtained when the precursor was sintered at 500C in air and then reduced at 325C in H2. Hysteresis loops measured at room temperature show a clear perpendicular magnetic anisotropy.Applied Physics A 01/2005; 80(2):439-442. · 1.63 Impact Factor -
Article: The fabrication and magnetic properties of nanowire-like iron oxide
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ABSTRACT: Nanowire-like iron oxides (α-Fe2O3, Fe3O4 and γ-Fe2O3) of diameter about 200 nm and length up to 8 µm were assembled into anodic aluminium oxide templates through electrodeposition followed by a heat-treating process. These wires have polycrystalline structures and consist of fine particles whose magnetic moments have preferred orientations in the templates. Some unique magnetic properties, such as perpendicular magnetic anisotropy in Fe3O4 wires, reduced transition temperature in α-Fe2O3 and Fe3O4 wires, and superparamagnetism in γ-Fe2O3 wires, were observed. The properties can be understood by their unique structures induced by reduced dimension and the competition of the shape and crystalline anisotropy.Journal of Physics Condensed Matter 06/2004; 16(25):4541. · 2.55 Impact Factor -
Article: Mikania micrantha H. B. K. in China – an overview
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ABSTRACT: As one of the worst invasive weeds in the world, Mikania micrantha H. B. K. spread to southern China after 1910 but without any natural enemies. Since the 1980s it has started to spread and invade widely. The weed has caused significant damage to many ecosystems in Guangdong province in recent years. This paper reviews the research in China on this weed, including its description, history of introduction together with information from morphological and physiological studies. The distribution of this invasive plant in China has been mapped and is presented together with damage being caused and analyses of soil types infested. The measures taken by the Chinese government for prevention and elimination are also discussed. Chinese scientists are now looking for effective biocontrol options to deal with this deleterious plant. Several native insects, mites and fungi have been reported to be able to control the reproduction of this weed in China, but no natural control has been achieved. Cuscuta sp., a native autoecious vine has recently been shown to suppress the growth of M. micrantha. Three major causes for the massive spread of this weed in southern China are presented together with recommendations for future control activities.Weed Research 01/2004; 44(1):42 - 49. · 1.92 Impact Factor -
Article: Preparation and characterization of haematite nanowire arrays
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ABSTRACT: Arrays of α-Fe2O3 nanowires embedded in anodic alumina membranes were obtained after heat-treating β-FeOOH nanowire arrays fabricated by electrochemical deposition. Haematite polycrystalline nanowires with maximum length of about 7µm and average diameter of about 120 nm were characterized by means of x-ray diffraction and transmission electron microscopy. The Morin temperature below 80 K and Néel temperature of about 350 K for the α-Fe2O3 nanowire arrays, far lower than those of bulk material, were measured by Mössbauer spectroscopy and using a Magnetic Property Measurement System.Journal of Physics Condensed Matter 02/2003; 15(9):1455. · 2.55 Impact Factor -
Article: CMS physics technical design report, volume II: Physics performance
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ABSTRACT: CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider ( LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking - through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start- up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb(-1) or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, B-s production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb(-1) to 30 fb(-1). The Standard Model processes include QCD, B-physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z(0) boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2-6 describe examples of full analyses, with photons, electrons, muons, jets, missing E-T, B-mesons and tau's, and for quarkonia in heavy ion collisions. Chapters 7-15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model.Physics Research Publications. -
Article: Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up
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ABSTRACT: Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated. -
Article: The CMS barrel calorimeter response to particle beams from 2 to 350 GeV/c
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ABSTRACT: The response of the CMS barrel calorimeter (electromagnetic plus hadronic) to hadrons, electrons and muons over a wide momentum range from 2 to 350 GeV/c has been measured. To our knowledge, this is the widest range of momenta in which any calorimeter system has been studied. These tests, carried out at the H2 beam-line at CERN, provide a wealth of information, especially at low energies. The analysis of the differences in calorimeter response to charged pions, kaons, protons and antiprotons and a detailed discussion of the underlying phenomena are presented. We also show techniques that apply corrections to the signals from the considerably different electromagnetic (EB) and hadronic (HB) barrel calorimeters in reconstructing the energies of hadrons. Above 5 GeV/c, these corrections improve the energy resolution of the combined system where the stochastic term equals 84.7±1.6% and the constant term is 7.4±0.8%. The corrected mean response remains constant within 1.3% rms. -
Article: Radiation hardness qualification of PbWO_4 scintillation crystals for the CMS Electromagnetic Calorimeter
[show abstract] [hide abstract]
ABSTRACT: Ensuring the radiation hardness of PbWO_4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered. -
Article: Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter
[show abstract] [hide abstract]
ABSTRACT: Ensuring the radiation hardness of PbWO4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered. -
Article: The CMS barrel calorimeter response to particle beams from 2 to 350 GeV/
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ABSTRACT: The online version of the original article can be found under doi:10.1140/epjc/s10052-009-0959-5. Now at: RWTH, I. Physikalisches Institut, Aachen, Germany. Now at: University of Pennsylvania, Philladelphia, PA, USA. Now at: ENEA, Casaccia Research Center, S. Maria di Galeria, Italy. At: Niğde University, Niğde, Turkey. Now at: Southern Methodist University, Dallas, TX, USA. At: Marmara University, Istanbul, Turkey. Deceased. At: Kafkas University, Kars, Turkey. Now at: University of Athens, Greece. Now at: Università del Piemonte Orientale, Novara, Italy. At: Süleyman Demirel University, Isparta, Turkey. At: Mersin University, Mersin, Turkey. At: Izmir Yüksek Teknoloji Enstitüsü, Izmir, Turkey.http://dx.doi.org/10.1140/epjc/s10052-009-1024-0. -
Article: The CMS experiment at the CERN LHC
[show abstract] [hide abstract]
ABSTRACT: The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10^(34) cm^(−2) s^(−1) (10^(27) cm^(−2) s^(−1)). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4π solid angle. Forward sampling calorimeters extend the pseudorapidity coverage to high values (|η| ≤ 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t.
Top Journals
Institutions
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2004
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Chinese Academy of Sciences
- South China Botanical Garden
Beijing, Beijing Shi, China
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