6,656 research outputs found

    Correlation Analysis of Chinese Pork Concept Stocks Based on Big Data

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    This article conducts an empirical study on the correlation between Chinese pork price and the fluctuation of the pork concept index. The first is to use Tushare financial data interface, crawler tools and other technologies to obtain initial data, then use machine learning SVM sentiment analysis to convert text data into structured data to pre-process and standardize the data, which is beneficial to SPSS.24 for correlation and multiple linear regression analysis. Finally came to the following conclusions: Firstly, the Chinese pork price has a significant positive correlation at the level of 0.01 with the pork concept index, and upstream and midstream companies in the pork industry chain are more affected by changes in pork prices. Therefore, investors can focus on pork price changes to guide investment decisions. Secondly, from the long-term analysis, investor sentiment has little effect on the stock price of pork stocks. Thirdly, weak correlation between Chinese macroeconomic factors and Chinese pork stock price

    A Novel Visual Word Co-occurrence Model for Person Re-identification

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    Person re-identification aims to maintain the identity of an individual in diverse locations through different non-overlapping camera views. The problem is fundamentally challenging due to appearance variations resulting from differing poses, illumination and configurations of camera views. To deal with these difficulties, we propose a novel visual word co-occurrence model. We first map each pixel of an image to a visual word using a codebook, which is learned in an unsupervised manner. The appearance transformation between camera views is encoded by a co-occurrence matrix of visual word joint distributions in probe and gallery images. Our appearance model naturally accounts for spatial similarities and variations caused by pose, illumination & configuration change across camera views. Linear SVMs are then trained as classifiers using these co-occurrence descriptors. On the VIPeR and CUHK Campus benchmark datasets, our method achieves 83.86% and 85.49% at rank-15 on the Cumulative Match Characteristic (CMC) curves, and beats the state-of-the-art results by 10.44% and 22.27%.Comment: Accepted at ECCV Workshop on Visual Surveillance and Re-Identification, 201

    PEG Branched Polymer for Functionalization of Nanomaterials with Ultralong Blood Circulation

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    Nanomaterials have been actively pursued for biological and medical applications in recent years. Here, we report the synthesis of several new poly(ethylene glycol) grafted branched-polymers for functionalization of various nanomaterials including carbon nanotubes, gold nanoparticles (NP) and gold nanorods (NRs), affording high aqueous solubility and stability for these materials. We synthesize different surfactant polymers based upon poly-(g-glutamic acid) (gPGA) and poly(maleic anhydride-alt-1-octadecene) (PMHC18). We use the abundant free carboxylic acid groups of gPGA for attaching lipophilic species such as pyrene or phospholipid, which bind to nanomaterials via robust physisorption. Additionally, the remaining carboxylic acids on gPGA or the amine-reactive anhydrides of PMHC18 are then PEGylated, providing extended hydrophilic groups, affording polymeric amphiphiles. We show that single-walled carbon nanotubes (SWNTs), Au NPs and NRs functionalized by the polymers exhibit high stability in aqueous solutions at different pHs, at elevated temperatures and in serum. Morever, the polymer-coated SWNTs exhibit remarkably long blood circulation (t1/2 22.1 h) upon intravenous injection into mice, far exceeding the previous record of 5.4 h. The ultra-long blood circulation time suggests greatly delayed clearance of nanomaterials by the reticuloendothelial system (RES) of mice, a highly desired property for in vivo applications of nanomaterials, including imaging and drug delivery

    Angle-dependent modulated spectral peaks of proton beams generated in ultrashort intense laser-solid interactions

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    Proton acceleration from 4μm thick aluminum foils irradiated by 30-TW Ti:sapphire laser pulses is investigated using an angle-resolved proton energy spectrometer. We find that a modulated spectral peak at ∼0.82MeV is presented at 2.5° off the target normal direction. The divergence angle of the modulated zone is 3.8°. Two-dimensional particle-in-cell simulations reveal that self-generated toroidal magnetic field at the rear surface of the target foil is responsible for the modulated spectral feature. The field deflects the low energy protons, resulting in the modulated energy spectrum with certain peaks

    Study of χcJ\chi_{cJ} radiative decays into a vector meson

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    The decays χcJγV\chi_{cJ}\to\gamma V (V=ϕ,ρ0,ωV=\phi, \rho^0, \omega) are studied with a sample of radiative \psip\to\gamma\chi_{cJ} events in a sample of (1.06\pm0.04)\times 10^{8} \psip events collected with the BESIII detector. The branching fractions are determined to be: B(χc1γϕ)=(25.8±5.2±2.3)×106{\cal B}(\chi_{c1}\to \gamma\phi)=(25.8\pm 5.2\pm 2.3)\times 10^{-6}, B(χc1γρ0)=(228±13±22)×106{\cal B}(\chi_{c1}\to \gamma\rho^0)=(228\pm 13\pm 22)\times 10^{-6}, and B(χc1γω)=(69.7±7.2±6.6)×106{\cal B}(\chi_{c1}\to \gamma\omega)=(69.7\pm 7.2\pm 6.6)\times 10^{-6}. The decay χc1γϕ\chi_{c1}\to \gamma\phi is observed for the first time. Upper limits at the 90% confidence level on the branching fractions for χc0\chi_{c0} and \chict decays into these final states are determined. In addition, the fractions of the transverse polarization component of the vector meson in χc1γV\chi_{c1}\to \gamma V decays are measured to be 0.290.120.09+0.13+0.100.29_{-0.12-0.09}^{+0.13+0.10} for χc1γϕ\chi_{c1}\to \gamma\phi, 0.158±0.0340.014+0.0150.158\pm 0.034^{+0.015}_{-0.014} for χc1γρ0\chi_{c1}\to \gamma\rho^0, and 0.2470.0870.026+0.090+0.0440.247_{-0.087-0.026}^{+0.090+0.044} for χc1γω\chi_{c1}\to \gamma\omega, respectively. The first errors are statistical and the second ones are systematic.Comment: 8 pages, 3 figure

    Observation of χc1\chi_{c1} decays into vector meson pairs ϕϕ\phi\phi, ωω\omega\omega, and ωϕ\omega\phi

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    Decays of χc1\chi_{c1} to vector meson pairs ϕϕ\phi\phi, ωω\omega\omega and ωϕ\omega\phi are observed for the first time using (106±4)×106(106\pm4)\times 10^6 \psip events accumulated at the BESIII detector at the BEPCII e+ee^+e^- collider. The branching fractions are measured to be (4.4±0.3±0.5)×104(4.4\pm 0.3\pm 0.5)\times 10^{-4}, (6.0±0.3±0.7)×104(6.0\pm 0.3\pm 0.7)\times 10^{-4}, and (2.2±0.6±0.2)×105(2.2\pm 0.6\pm 0.2)\times 10^{-5}, for χc1ϕϕ\chi_{c1}\to \phi\phi, ωω\omega\omega, and ωϕ\omega\phi, respectively. The observation of χc1\chi_{c1} decays into a pair of vector mesons ϕϕ\phi\phi, ωω\omega\omega and ωϕ\omega\phi indicates that the hadron helicity selection rule is significantly violated in χcJ\chi_{cJ} decays. In addition, the measurement of χcJωϕ\chi_{cJ}\to \omega\phi gives the rate of doubly OZI-suppressed decay. Branching fractions for χc0\chi_{c0} and χc2\chi_{c2} decays into other vector meson pairs are also measured with improved precision.Comment: 4 pages, 2 figure

    First Observation of the Decays chi_{cJ} -> pi^0 pi^0 pi^0 pi^0

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    We present a study of the P-wave spin -triplet charmonium chi_{cJ} decays (J=0,1,2) into pi^0 pi^0 pi^0 pi^0. The analysis is based on 106 million \psiprime decays recorded with the BESIII detector at the BEPCII electron positron collider. The decay into the pi^0 pi^0 pi^0 pi^0 hadronic final state is observed for the first time. We measure the branching fractions B(chi_{c0} -> pi^0 pi^0 pi^0 pi^0)=(3.34 +- 0.06 +- 0.44)*10^{-3}, B(chi_{c1} -> pi^0 pi^0 pi^0 pi^0)=(0.57 +- 0.03 +- 0.08)*10^{-3}, and B(chi_{c2} -> pi^0 pi^0 pi^0 pi^0)=(1.21 +- 0.05 +- 0.16)*10^{-3}, where the uncertainties are statistical and systematical, respectively.Comment: 7 pages, 3 figure

    Study of J/ψJ/\psi and ψ(3686)Σ(1385)0Σˉ(1385)0\psi(3686)\rightarrow\Sigma(1385)^{0}\bar\Sigma(1385)^{0} and Ξ0Ξˉ0\Xi^0\bar\Xi^{0}

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    We study the decays of J/ψJ/\psi and ψ(3686)\psi(3686) to the final states Σ(1385)0Σˉ(1385)0\Sigma(1385)^{0}\bar\Sigma(1385)^{0} and Ξ0Ξˉ0\Xi^0\bar\Xi^{0} based on a single baryon tag method using data samples of (1310.6±7.0)×106(1310.6 \pm 7.0) \times 10^{6} J/ψJ/\psi and (447.9±2.9)×106(447.9 \pm 2.9) \times 10^{6} ψ(3686)\psi(3686) events collected with the BESIII detector at the BEPCII collider. The decays to Σ(1385)0Σˉ(1385)0\Sigma(1385)^{0}\bar\Sigma(1385)^{0} are observed for the first time. The measured branching fractions of J/ψJ/\psi and ψ(3686)Ξ0Ξˉ0\psi(3686)\rightarrow\Xi^0\bar\Xi^{0} are in good agreement with, and much more precise, than the previously published results. The angular parameters for these decays are also measured for the first time. The measured angular decay parameter for J/ψΣ(1385)0Σˉ(1385)0J/\psi\rightarrow\Sigma(1385)^{0}\bar\Sigma(1385)^{0}, α=0.64±0.03±0.10\alpha =-0.64 \pm 0.03 \pm 0.10, is found to be negative, different to the other decay processes in this measurement. In addition, the "12\% rule" and isospin symmetry in the J/ψJ/\psi and ψ(3686)ΞΞˉ\psi(3686)\rightarrow\Xi\bar\Xi and Σ(1385)Σˉ(1385)\Sigma(1385)\bar{\Sigma}(1385) systems are tested.Comment: 11 pages, 7 figures. This version is consistent with paper published in Phys.Lett. B770 (2017) 217-22

    VHL substrate transcription factor ZHX2 as an oncogenic driver in clear cell renal cell carcinoma

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    Inactivation of the von Hippel-Lindau (VHL) E3 ubiquitin ligase protein is a hallmark of clear cell renal cell carcinoma (ccRCC). Identifying how pathways affected by VHL loss contribute to ccRCC remains challenging. We used a genome-wide in vitro expression strategy to identify proteins that bind VHL when hydroxylated. Zinc fingers and homeoboxes 2 (ZHX2) was found as a VHL target, and its hydroxylation allowed VHL to regulate its protein stability. Tumor cells from ccRCC patients with VHL loss-of-function mutations usually had increased abundance and nuclear localization of ZHX2. Functionally, depletion of ZHX2 inhibited VHL-deficient ccRCC cell growth in vitro and in vivo. Mechanistically, integrated chromatin immunoprecipitation sequencing and microarray analysis showed that ZHX2 promoted nuclear factor κB activation. These studies reveal ZHX2 as a potential therapeutic target for ccRCC

    Observation of an anomalous line shape of the ηπ+π\eta^{\prime}\pi^{+}\pi^{-} mass spectrum near the ppˉp\bar{p} mass threshold in J/ψγηπ+πJ/\psi\rightarrow\gamma\eta^{\prime}\pi^{+}\pi^{-}

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    Using 1.09×1091.09\times10^{9} J/ψJ/\psi events collected by the BESIII experiment in 2012, we study the J/ψγηπ+πJ/\psi\rightarrow\gamma\eta^{\prime}\pi^{+}\pi^{-} process and observe a significant abrupt change in the slope of the ηπ+π\eta^{\prime}\pi^{+}\pi^{-} invariant mass distribution at the proton-antiproton (ppˉp\bar{p}) mass threshold. We use two models to characterize the ηπ+π\eta^{\prime}\pi^{+}\pi^{-} line shape around 1.85 GeV/c21.85~\text{GeV}/c^{2}: one which explicitly incorporates the opening of a decay threshold in the mass spectrum (Flatt\'{e} formula), and another which is the coherent sum of two resonant amplitudes. Both fits show almost equally good agreement with data, and suggest the existence of either a broad state around 1.85 GeV/c21.85~\text{GeV}/c^{2} with strong couplings to ppˉp\bar{p} final states or a narrow state just below the ppˉp\bar{p} mass threshold. Although we cannot distinguish between the fits, either one supports the existence of a ppˉp\bar{p} molecule-like state or bound state with greater than 7σ7\sigma significance
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