1,338 research outputs found

    An Anomaly-Based Method for Identifying Signals of Spring and Autumn Low-Temperature Events in the Yangtze River Valley, China

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    June 2015 QIAN ET AL. Vol. 54 1216-123

    Excited Heavy Quarkonium Production at the LHC through WW-Boson Decays

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    Sizable amount of heavy-quarkonium events can be produced through WW-boson decays at the LHC. Such channels will provide a suitable platform to study the heavy-quarkonium properties. The "improved trace technology", which disposes the amplitude M{\cal M} at the amplitude-level, is helpful for deriving compact analytical results for complex processes. As an important new application, in addition to the production of the lower-level Fock states (QQˉ)[1S]>|(Q\bar{Q'})[1S]> and (QQˉ)[1P]>|(Q\bar{Q'})[1P]>, we make a further study on the production of higher-excited (QQˉ)>|(Q\bar{Q'})>-quarkonium Fock states (QQˉ)[2S]>|(Q\bar{Q'})[2S]>, (QQˉ)[3S]>|(Q\bar{Q'})[3S]> and (QQˉ)[2P]>|(Q\bar{Q'})[2P]>. Here (QQˉ)>|(Q\bar{Q'})> stands for the (ccˉ)>|(c\bar{c})>-charmonium, (cbˉ)>|(c\bar{b})>-quarkonium and (bbˉ)>|(b\bar{b})>-bottomonium respectively. We show that sizable amount of events for those higher-excited states can also be produced at the LHC. Therefore, we need to take them into consideration for a sound estimation.Comment: 7 pages, 9 figures and 6 tables. Typo errors are corrected, more discussions and two new figures have been adde

    Doubly Heavy Baryon Production at A High Luminosity e+ee^+ e^- Collider

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    Within the framework of nonrelativistic QCD, we make a detailed discussion on the doubly heavy baryon production through the e+ee^+ e^- annihilation channel, e+eγ/Z0ΞQQ+Qˉ+Qˉe^{+}e^{-}\rightarrow\gamma/Z^0 \rightarrow \Xi_{QQ^{\prime}} +\bar{Q} +\bar{Q^{\prime}}, at a high luminosity e+ee^{+}e^{-} collider. Here Q()Q^{(\prime)} stands for the heavy bb or cc quark. In addition to the channel through the usually considered diquark state (QQ)[3S1]3ˉ(QQ^{\prime})[^3S_1]_{\bf\bar{3}}, contributions from the channels through other same important diquark states such as (QQ)[1S0]6(QQ^{\prime})[^1S_0]_{\bf 6} have also been discussed. Uncertainties for the total cross sections are predicted by taking mc=1.80±0.30m_c=1.80\pm0.30 GeV and mb=5.10±0.40m_b=5.10\pm0.40 GeV. At a super ZZ-factory running around the Z0Z^0 mass and with a high luminosity up to L10341036cm2s1{\cal L} \propto 10^{34}\sim 10^{36}{\rm cm}^{-2} {\rm s}^{-1}, we estimate that about 1.1×10571.1\times10^{5 \sim 7} Ξcc\Xi_{cc} events, 2.6×10572.6\times10^{5 \sim 7} Ξbc\Xi_{bc} events and 1.2×10461.2\times 10^{4 \sim 6} Ξbb\Xi_{bb} events can be generated in one operation year. Such a ZZ-factory, thus, will provide a good platform for studying the doubly heavy baryons in comparable to the CERN large hadronic collider.Comment: 9 pages, 4 figures. To be published in Phys.Rev.

    Optimized Nonlinear PRI Variation Strategy Using Knowledge-Guided Genetic Algorithm for Staggered SAR Imaging

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    Staggered synthetic aperture radar (SAR), which operates with variable pulse repetition interval (PRI), staggers blind areas to solve the blind range problem caused by constant PRI in conventional high-resolution wide-swath SAR imaging. The PRI variation strategy determines the blind area distribution, and thus has a significant influence on the imaging performance in staggered mode. Generally, the existing strategies based on linear PRI variation can control the blind areas in a straightforward way, which has achieved impressive results. However, the linearity of the PRI variation imposes regularity or even periodicity on the locations of the blind areas, which limits the distribution of the blind areas. The imaging performance has the potential to be further improved by introducing much more irregularity into the PRI sequences. To this end, this article proposes an optimized nonlinear PRI variation strategy for staggered SAR mode. First, a novel objective function is defined that quantitatively measures the uniformity of the blind area distribution along the slant range and the discontinuity of the blind area distribution along the azimuth. Subsequently, the optimum nonlinear PRI variation strategy is found using an optimization problem and the proposed objective function. A knowledge-guided genetic algorithm is proposed to solve the optimization problem. Comparisons with the existing linear variation strategies show that the proposed strategy can provide a superior imaging performance after reconstruction with a lower objective function value. Simulations and experiments on raw data generated in staggered SAR mode are performed to verify the effectiveness of the optimized nonlinear PRI variation strategy

    Heavy Quarkonium Production at LHC through WW Boson Decays

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    The production of the heavy (ccˉ)(c\bar{c})-quarkonium, (cbˉ)(c\bar{b})-quarkonium and (bbˉ)(b\bar{b})-quarkonium states ((QQˉ)(Q\bar{Q'})-quarkonium for short), via the W+W^+ semi-inclusive decays, has been systematically studied within the framework of the non-relativistic QCD. In addition to the two color-singlet SS-wave states, we also discuss the production of the four color-singlet PP-wave states (QQˉ)(1P1)1>|(Q\bar{Q'})(^1P_1)_{\bf 1}> and (QQˉ)(3PJ)1>(Q\bar{Q'})(^3P_J)_{\bf 1}> (with J=(1,2,3)J=(1,2,3)) together with the two color-octet components (QQˉ)(1S0)8>|(Q\bar{Q'})(^1S_0)_{\bf 8}> and (QQˉ)(3S1)8>|(Q\bar{Q'})(^3S_1)_{\bf 8}>. Improved trace technology is adopted to derive the simplified analytic expressions at the amplitude level, which shall be useful for dealing with the following cascade decay channels. At the LHC with the luminosity L1034cm2s1{\cal L}\propto 10^{34}cm^{-2}s^{-1} and the center-of-mass energy S=14\sqrt{S}=14 TeV, sizable heavy-quarkonium events can be produced through the W+W^+ boson decays, i.e. 2.57×1062.57\times10^6 ηc\eta_c, 2.65×1062.65\times10^6 J/ΨJ/\Psi and 2.40×1062.40\times10^6 PP-wave charmonium events per year can be obtained; and 1.01×1051.01\times10^5 BcB_c, 9.11×1049.11\times10^4 BcB^*_c and 3.16×1043.16\times10^4 PP-wave (cbˉ)(c\bar{b})-quarkonium events per year can be obtained. Main theoretical uncertainties have also been discussed. By adding the uncertainties caused by the quark masses in quadrature, we obtain ΓW+(ccˉ)+csˉ=524.8258.4+396.3\Gamma_{W^+\to (c\bar{c})+c\bar{s}} =524.8^{+396.3}_{-258.4} KeV, ΓW+(cbˉ)+bsˉ=13.53.29+4.73\Gamma_{W^+\to (c\bar{b})+b\bar{s}} =13.5^{+4.73}_{-3.29} KeV, ΓW+(cbˉ)+ccˉ=1.740.73+1.98\Gamma_{W^+\to (c\bar{b})+c\bar{c}}= 1.74^{+1.98}_{-0.73} KeV and ΓW+(bbˉ)+cbˉ=38.69.69+13.4\Gamma_{W^+\to (b\bar{b})+c\bar{b}}= 38.6^{+13.4}_{-9.69} eV.Comment: 24 pages, 12 figures. References updated. To be published in Phys.Rev. D. To match the published versio

    Transcriptome Analysis of Metapenaeus affinis Reveals Genes Involved in Gonadal Development

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    Metapenaeus affinis is a crustacean with important commercial value in the fishery of the South China Sea. Overfishing has resulted in the decline of the wild population and germplasm degradation. However, there is little background knowledge about its gonadal development, and there is a lack of research on the development of this species. To better understand the molecular regulatory mechanisms during gonadal development, here, we performed RNA-Seq on immature and mature ovaries and compared their transcriptomic signatures. 126,930,488 and 122,677,356 clean sequencing reads were obtained from the Illumina sequencing platform, respectively. 394 differentially expressed genes (DEGs) were identified, of which 136 were up-regulated, and 258 were down-regulated. Further analysis revealed rich transcriptional sequences, which have homology with genes related to reproduction and development. Expression patterns of COX, GPX, E3s, PCNA, STPK, and other genes were changed during ovarian development. Validation by qRT-PCR demonstrated the reliability of RNA-Seq. This study has made a significant contribution to the currently available sequence data of M. affinis and provided reference data for the development of genetic and breeding work

    Dynamical tunneling-assisted coupling of high-Q deformed microcavities using a free-space beam

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    We investigate the efficient free-space excitation of high-Q resonance modes in deformed microcavities via dynamical tunneling-assisted coupling. A quantum scattering theory is employed to study the free-space transmission properties, and it is found that the transmission includes the contribution from (1) the off-resonance background and (2) the on-resonance modulation, corresponding to the absence and presence of high-Q modes, respectively. The theory predicts asymmetric Fano-like resonances around high-Q modes in background transmission spectra, which are in good agreement with our recent experimental results. Dynamical tunneling across Kolmogorov-Arnold-Moser tori, which plays an essential role in the Fano-like resonance, is further studied. This efficient free-space coupling holds potential advantages to simplify experimental conditions and excite high-Q modes in higher-index-material microcavities

    Poly[[(μ3-5,6-dicarboxy­bicyclo­[2.2.2]oct-7-ene-2,3-dicarboxyl­ato)(1,10-phenanthroline)copper(II)] monohydrate]

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    In the title compound, {[Cu(C12H10O8)(C12H8N2)]·H2O}n, the CuII ion is five-coordinated by two N atoms from one phenanthroline ligand and three O atoms from three different H2 L 2− anions (H4 L is bicyclo­[2.2.2]oct-7-ene-2,3,5,6-tetra­carboxylic acid) in a distorted square-pyramidal geometry. Each H2 L 2− ion bridges three CuII atoms to form a zigzag sheet parallel to the ab plane. The crystal structure is consolidated by O—H⋯O hydrogen bonds

    International Journal of Smart Grid and Clean Energy 3D visualized data management for network devices based on multilevel caches

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    Abstract Three dimensional visualization technologies are dramatically improving convenience and efficiency in modern industrial managements. In this paper, a novel multilevel caches-based 3D visualization system for managing device data, which could be applied for displaying 3D scenes and processing device data simultaneously, is investigated. The system is fast-response, compared to conventional strategies. This work may provide helpful references and inspirations for applications about computer based visualization, complex data management and network communications
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