2,603 research outputs found

    Supereulerian Locally Semicomplete Multipartite Digraphs

    Get PDF
    In this paper, we generalized the above known results and show that this conjecture holds for every strong locally semicomplete multipartite digraph

    Full-heavy tetraquark states and their evidences in the LHCb di-J/ψJ/\psi spectrum

    Full text link
    In the framework of a nonrelativistic potential quark model (NRPQM) for heavy quark system, we investigate the mass spectrum of the PP-wave tetraquark states of cccˉcˉcc\bar{c}\bar{c} and bbbˉbˉbb\bar{b}\bar{b}. The Hamiltonian contains a linear confinement potential and parameterized one-gluon-exchange potential which includes a Coulomb type potential and spin-dependent potentials. The full-heavy tetraquark system is solved by a harmonic oscillator expansion method. With the same parameters fixed by the charmonium and bottomonium spectra, we obtained the full spectra for the SS and PP-wave heavy tetraquark states. We find that the narrow structure around 6.9 GeV recently observed at LHCb in the di-J/ψJ/\psi invariant mass spectrum can be naturally explained by the PP-wave cccˉcˉcc\bar{c}\bar{c} states. Meanwhile, the observed broad structure around 6.26.86.2\sim 6.8 GeV can be consistently explained by the SS-wave states around 6.5 GeV predicted in our previous work. Some contributions from those suppressed low-lying PP-wave states around 6.7 GeV are also possible. Other decay channels are implied in such a scenario and they can be investigated by future experimental analysis. Considering the large discovery potential at LHCb, we give our predictions of the PP-wave bbbˉbˉbb\bar{b}\bar{b} states which can be searched for in the future.Comment: 5 page, 1 figur

    All-heavy pentaquarks in a nonrelativistic potential quark model

    Full text link
    In a nonrelativistic potential quark model framework, we carry out a serious calculation of the all-heavy pentaquarks by adopting the explicitly correlated Gaussian method.A complete mass spectrum for the 1S1S states is obtained. For the cccccˉcccc\bar{c}, ccccbˉcccc\bar{b}, bbbbcˉbbbb\bar{c}, bbbbbˉbbbb\bar{b}, ccbbcˉccbb\bar{c}, and bbccbˉbbcc\bar{b} systems, the obtained states are compact and lie far above the lowest dissociation baryon-meson threshold. While, in the cccbcˉcccb\bar{c}, cccbbˉcccb\bar{b}, bbbccˉbbbc\bar{c}, and bbbcbˉbbbc\bar{b} systems with {123}45ˉ\{123\}4\bar{5} symmetry, the two low-lying configurations with JP=5/2J^P=5/2^- and 3/23/2^- have a typical molecular structure due to the special role of the color-Coulomb interactions, they may be good candidates of stable states below the dissociation baryon-meson thresholds.Comment: 12 pages, 3 figure

    Tris{2-meth­oxy-6-[(4-methyl­phenyl)­iminiometh­yl]phenolato-κ2 O,O′}tris­(thio­cyanato-κN)cerium(III)

    Get PDF
    The asymmetric unit of the title compound, [Ce(NCS)3(C15H15NO2)3], contains three Schiff base 2-methoxy-6-[(4-methyl­phenyl)iminometh­yl]­phenol (HL) ligands and three independent thio­cyanate ions that coordinate the cerium ion via their N atoms. The protonated imine N atoms are involved in an intra­molecular hydrogen bond with the respective phenoxide group. The Ce(III) ion exhibits a coordination number of nine

    Diagnostic value of two dimensional shear wave elastography combined with texture analysis in early liver fibrosis.

    Get PDF
    BACKGROUND: Staging diagnosis of liver fibrosis is a prerequisite for timely diagnosis and therapy in patients with chronic hepatitis B. In recent years, ultrasound elastography has become an important method for clinical noninvasive assessment of liver fibrosis stage, but its diagnostic value for early liver fibrosis still needs to be further improved. In this study, the texture analysis was carried out on the basis of two dimensional shear wave elastography (2D-SWE), and the feasibility of 2D-SWE plus texture analysis in the diagnosis of early liver fibrosis was discussed. AIM: To assess the diagnostic value of 2D-SWE combined with textural analysis in liver fibrosis staging. METHODS: This study recruited 46 patients with chronic hepatitis B. Patients underwent 2D-SWE and texture analysis; Young\u27s modulus values and textural patterns were obtained, respectively. Textural pattern was analyzed with regard to contrast, correlation, angular second moment (ASM), and homogeneity. Pathological results of biopsy specimens were the gold standard; comparison and assessment of the diagnosis efficiency were conducted for 2D-SWE, texture analysis and their combination. RESULTS: 2D-SWE displayed diagnosis efficiency in early fibrosis, significant fibrosis, severe fibrosis, and early cirrhosis (AUC \u3e 0.7, P \u3c 0.05) with respective AUC values of 0.823 (0.678-0.921), 0.808 (0.662-0.911), 0.920 (0.798-0.980), and 0.855 (0.716-0.943). Contrast and homogeneity displayed independent diagnosis efficiency in liver fibrosis stage (AUC \u3e 0.7, P \u3c 0.05), whereas correlation and ASM showed limited values. AUC of contrast and homogeneity were respectively 0.906 (0.779-0.973), 0.835 (0.693-0.930), 0.807 (0.660-0.910) and 0.925 (0.805-0.983), 0.789 (0.639-0.897), 0.736 (0.582-0.858), 0.705 (0.549-0.883) and 0.798 (0.650-0.904) in four liver fibrosis stages, which exhibited equivalence to 2D-SWE in diagnostic efficiency (P \u3e 0.05). Combined diagnosis (PRE) displayed diagnostic efficiency (AUC \u3e 0.7, P \u3c 0.01) for all fibrosis stages with respective AUC of 0.952 (0.841-0.994), 0.896 (0.766-0.967), 0.978 (0.881-0.999), 0.947 (0.835-0.992). The combined diagnosis showed higher diagnosis efficiency over 2D-SWE in early liver fibrosis (P \u3c 0.05), whereas no significant differences were observed in other comparisons (P \u3e 0.05). CONCLUSION: Texture analysis was capable of diagnosing liver fibrosis stage, combined diagnosis had obvious advantages in early liver fibrosis, liver fibrosis stage might be related to the hepatic tissue hardness distribution
    corecore