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81.
Ablikim M Achasov MN An L An Q An ZH Bai JZ Baldini R Ban Y Becker J Berger N Bertani M Bian JM Bondarenko O Boyko I Briere RA Bytev V Cai X Cao GF Cao XX Chang JF Chelkov G Chen G Chen HS Chen JC Chen ML Chen SJ Chen Y Chen YB Cheng HP Chu YP Cronin-Hennessy D Dai HL Dai JP Dedovich D Deng ZY Denysenko I Destefanis M Ding Y Dong LY Dong MY Du SX Duan MY Fan RR Fang J Fang SS Feng CQ Fu CD Fu JL Gao Y Geng C Goetzen K Gong WX Greco M Grishin S Gu MH Gu YT Guan YH Guo AQ Guo LB Guo YP Hao XQ 《Physical review letters》2011,107(9):092001
Using (106±4)×10?? ψ(3686) events accumulated with the BESIII detector at the BEPCII e?e? collider, we present the first measurement of decays of χ(c1) to vector meson pairs φφ, ωω, and ωφ. The branching fractions are measured to be (4.4±0.3±0.5)×10??, (6.0±0.3±0.7)×10??, and (2.2±0.6±0.2)×10??, for χ(c1)→φφ, ωω, and ωφ, respectively, which indicates that the hadron helicity selection rule is significantly violated in χ(cJ) decays. In addition, the measurement of χ(cJ)→ωφ provides the first indication of the rate of doubly OZI-suppressed χ(cJ) decay. Finally, we present improved measurements for the branching fractions of χ(c0) and χ(c2) to vector meson pairs. 相似文献
82.
Aamodt K Abelev B Abrahantes Quintana A Adamová D Adare AM Aggarwal MM Aglieri Rinella G Agocs AG Agostinelli A Aguilar Salazar S Ahammed Z Ahmad N Ahmad Masoodi A Ahn SU Akindinov A Aleksandrov D Alessandro B Alfaro Molina R Alici A Alkin A Almaráz Aviña E Alt T Altini V Altsybeev I Andrei C Andronic A Anguelov V Anson C Antičić T Antinori F Antonioli P Aphecetche L Appelshäuser H Arbor N Arcelli S Arend A Armesto N Arnaldi R Aronsson T Arsene IC Arslandok M Asryan A Augustinus A Averbeck R 《Physical review letters》2011,107(3):032301
We report on the first measurement of the triangular v3, quadrangular v4, and pentagonal v5 charged particle flow in Pb-Pb collisions at sqrt(s(NN)) = 2.76 TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow v2 and v3 have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients. 相似文献
83.
Lin Y Zhang L Mao HK Chow P Xiao Y Baldini M Shu J Mao WL 《Physical review letters》2011,107(17):175504
Compressing glassy carbon above 40 GPa, we have observed a new carbon allotrope with a fully sp(3)-bonded amorphous structure and diamondlike strength. Synchrotron x-ray Raman spectroscopy revealed a continuous pressure-induced sp(2)-to-sp(3) bonding change, while x-ray diffraction confirmed the perseverance of noncrystallinity. The transition was reversible upon releasing pressure. Used as an indenter, the glassy carbon ball demonstrated exceptional strength by reaching 130 GPa with a confining pressure of 60 GPa. Such an extremely large stress difference of >70 GPa has never been observed in any material besides diamond, indicating the high hardness of this high-pressure carbon allotrope. 相似文献
84.
Adam J Bai X Baldini AM Baracchini E Bemporad C Boca G Cattaneo PW Cavoto G Cei F Cerri C de Bari A De Gerone M Doke T Dussoni S Egger J Fratini K Fujii Y Galli L Gallucci G Gatti F Golden B Grassi M Grigoriev DN Haruyama T Hildebrandt M Hisamatsu Y Ignatov F Iwamoto T Kettle PR Khazin BI Kiselev O Korenchenko A Kravchuk N Maki A Mihara S Molzon W Mori T Mzavia D Natori H Nicolò D Nishiguchi H Nishimura Y Ootani W Panareo M Papa A Pazzi R Piredda G Popov A Renga F Ritt S Rossella M Sawada R 《Physical review letters》2011,107(17):171801
We present a new result based on an analysis of the data collected by the MEG detector at the Paul Scherrer Institut in 2009 and 2010, in search of the lepton-flavor-violating decay μ(+)e(+)γ. The likelihood analysis of the combined data sample, which corresponds to a total of 1.8×10(14) muon decays, gives a 90% C.L. upper limit of 2.4×10(-12) on the branching ratio of the μ(+)→e(+)γ decay, constituting the most stringent limit on the existence of this decay to date. 相似文献
85.
Aamodt K;ALICE Collaboration Abrahantes Quintana A Adamová D Adare AM Aggarwal MM Aglieri Rinella G Agocs AG Aguilar Salazar S Ahammed Z Ahmad N Ahmad Masoodi A Ahn SU Akindinov A Aleksandrov D Alessandro B Alfaro Molina R Alici A Alkin A Almaráz Aviña E Alt T Altini V Altinpinar S Altsybeev I Andrei C Andronic A Anguelov V Anson C Antičić T Antinori F Antonioli P Aphecetche L Appelshäuser H Arbor N Arcelli S Arend A Armesto N Arnaldi R Aronsson T Arsene IC Asryan A Augustinus A Averbeck R 《Physical review letters》2011,106(3):032301
The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions. 相似文献
86.
Analytical and Bioanalytical Chemistry - 相似文献
87.
Research findings have shown that microphones can be uniquely identified by audio recordings since physical features of the microphone components leave repeatable and distinguishable traces on the audio stream. This property can be exploited in security applications to perform the identification of a mobile phone through the built-in microphone. The problem is to determine an accurate but also efficient representation of the physical characteristics, which is not known a priori. Usually there is a trade-off between the identification accuracy and the time requested to perform the classification. Various approaches have been used in literature to deal with it, ranging from the application of handcrafted statistical features to the recent application of deep learning techniques. This paper evaluates the application of different entropy measures (Shannon Entropy, Permutation Entropy, Dispersion Entropy, Approximate Entropy, Sample Entropy, and Fuzzy Entropy) and their suitability for microphone classification. The analysis is validated against an experimental dataset of built-in microphones of 34 mobile phones, stimulated by three different audio signals. The findings show that selected entropy measures can provide a very high identification accuracy in comparison to other statistical features and that they can be robust against the presence of noise. This paper performs an extensive analysis based on filter features selection methods to identify the most discriminating entropy measures and the related hyper-parameters (e.g., embedding dimension). Results on the trade-off between accuracy and classification time are also presented. 相似文献
88.
G. Baldini Huang Fu-Hua G. Varani L. Cordone S. L. Fornili G. Onori 《Il Nuovo Cimento D》1985,6(6):618-630
Summary The isothermal denaturation of calf thymus DNA, induced by the presence of some monohydric alcohols in the solution, was investigated.
Measurements were performed at a temperature (67.2°C) at which the denaturation, in the absence of alcohols, is about 20%
and melting profiles at varying temperatures were also recorded. Results show that with increasing alcohol concentration and
alkyl group size DNA denaturation first reaches a maximum and then falls back. This behaviour, ascribed to ?unusual? water
properties as inferred also from compressibility measurements, indicates that hydrophobic and electrostatic effects are connected
in a complex way.
Partially supported by Consiglio Nazionale delle Ricerche, Italy. 相似文献
89.
D. Allasia C. Angelini A. Baldini S. Barlag L. Bertanza A. Bigi V. Bisi F. Bobisut T. Bolognese R. Bonarelli E. Calimani R. Casali P. Capiluppi S. Ciampolillo J. Derkaoui E. De Wolf M.L. Faccini-Turleur R. Wigmans 《Nuclear Physics B》1984,239(2):301-310
The total νμ and nucleon charged-current cross sections have been measured in BEBC filled with deuterium and exposed to the wide-band neutrino and antineutrino beams at the CERN-SPS. Assuming a linear energy dependence for the cross sections, σ = aE(?ν, we obtained the coefficients , where the quoted error is mainly systematic. The ratio of the cross sections is .We also determined the ratio of the charged-current cross section for neutrino interactions on neutrons and protons R = σνn/σνp = 2.10 ± 0.08 (statistical) ±0.22 (sysetmatic). The dependence of R on the variables x, y and Eν is discussed. 相似文献
90.
Multivalency is a powerful concept which explains the strong binding observed in biological systems and guides the design and synthesis of ligands for self-assembly and molecular recognition in Chemistry. The phenol-formaldehyde cyclic oligomers, called calixarenes, have been used as scaffolds for the synthesis of multivalent ligands thanks to the fact that they have a variable number of reactive positions for attaching the ligating functions, well defined conformational properties and, in some cases, cavities of molecular dimensions eventually able to encapsulate guest species. This tutorial review illustrates the fundamental aspects of multivalency and the properties of calixarene-based multivalent ligands in lectin binding and inhibition, DNA condensation and cell transfection, protein surface recognition, self-assembly, crystal engineering, and nanofabrication. 相似文献