498 research outputs found

    Three Dimensional Imaging of the Nucleon and Semi-Inclusive High Energy Reactions

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    We present a short overview on the studies of transverse momentum dependent parton distribution functions of the nucleon. The aim of such studies is to provide a three dimensional imagining of the nucleon and a comprehensive description of semi-inclusive high energy reactions. By comparing with the theoretical framework that we have for the inclusive deep inelastic lepton-nucleon scattering and the one-dimensional imaging of the nucleon, we summarize what we need to do in order to construct such a comprehensive theoretical framework for semi-inclusive processes in terms of three dimensional gauge invariant parton distributions. After that, we present an overview of what we have already achieved with emphasize on the theoretical framework for semi-inclusive reactions in leading order perturbative QCD but with leading and higher twist contributions. We summarize in particular the results for the differential cross section and the azimuthal spin asymmetries in terms of the gauge invariant transverse momentum dependent parton distribution functions. We also briefly summarize the available experimental results on semi-inclusive reactions and parameterizations of transverse momentum dependent parton distributions extracted from them and make an outlook for the future studies.Comment: 20 pages, 7 figure

    4,4′-Bis(benzimidazol-1-yl)biphen­yl

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    The mol­ecule of the title compound, C26H18N4, resides on a crystallographic inversion centre with a dihedral angle of 44.94 (5)° between the benzimidazole ring system and the benzene ring. The primary hydrogen bond is C—H⋯N and inversion-related pairs of these generate a chain of rings along the c-axis direction; π⋯π stacking involving the benzimidazole groups with inter­planar separations of ca 3.4 Å complete the inter­actions

    The Spin Alignment of Vector Mesons in High Energy pp Collisions

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    The spin alignment of vector meson produced in high energy reactions is determined by the spin-dependent fragmentation function D1LL(z,μf)D_{1LL} (z,\mu_f) that is shown to be independent of the polarization of the fragmenting quark. In this paper, we extract the spin-dependent fragmentation function D1LL(z,μf)D_{1LL} (z,\mu_f) from data on the spin alignment of K0K^{*0} in e+ee^+e^- annihilation at LEP in two different scenarios and apply them to make predictions in pppp collisions. We make detailed analysis of contributions from different sub-processes and show that the spin alignment should be quite significant also in high energy pppp collisions.Comment: 12 pages, 16 fgiures,version printed in PR

    Quantitative analysis and pharmacokinetic study of a novel diarylurea EGFR inhibitor (ZCJ14) in rat plasma using a validated LC-MS/MS method

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    1-(4-(Pyrrolidin-1-yl-methyl)phenyl)-3-(4-((3-(trifluoromethyl)phenyl)amino)quinazolin-6-yl)urea (ZCJ14), a novel epidermal growth factor receptor (EGFR) inhibitor, with diarylurea moiety, displays anticancer effect. In the present study, an LC-MS/MS method was established to determine the concentration of ZCJ14 in rat plasma. Furthermore, the method was applied to investigate the pharmacokinetic characteristics of ZCJ14. Chromatographic separation of ZCJ14 and internal standard (IS) [1-phenyl-3-(4-((3-(trifluoromethyl)phenyl)amino)quinazolin-6-yl)urea] was accomplished by gradient elution using the Kromasil C18 column. The selected reaction monitoring transitions were performed at m/z 507.24→436.18 and 424.13→330.96 for ZCJ14 and IS, resp. The established method was linear over the concentration range of 10–1000 ng mL–1. The intra- and inter-day precisions were < 11.0 % (except for LLOQ which was up to 14.3 %) and the respective accuracies were within the range of 87.5–99.0 %. The extraction recovery and matrix effect were within the range of 88.4–104.5 % and 87.3–109.9 %, resp. ZCJ14 was stable under all storage conditions. The validated method was successfully applied to the pharmacokinetic study of ZCJ14 in rats, and the pharmacokinetic parameters have been determined. The oral bioavailability of ZCJ14 was found to be 46.1 %. Overall, this accurate and reliable quantification method might be useful for other diarylurea moiety-containing drugs

    Origin of the Oligocene Tuolangla porphyry-skarn Cu-W-Mo deposit in Lhasa terrane, southern Tibet

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    Although some porphyry-skarn deposits occur in post-collisional extensional settings, the post-collisional deposits remain poorly understood. Here the authors describe the igneous geology, and mineralization history of Tuolangla, a newly-discovered porphyry-skarn Cu-W-Mo deposit in southern Tibet that belongs to the post-collisional class. The deposit is associated with Lower Cretaceous Bima Formation. It was intruded by granodiorite porphyry intrusions at about 23.1 Ma. Field investigation indicated that mineralization is spatially and temporally associated with granodiorite porphyry. Molybdenite yielded a Re-Os weighted mean age of 23.5 +/- 0.3 Ma and is considered to represent the age of skarn mineralization at the deposit. The delta S-34 values of sulfides, concentrated in a range between 0.6 parts per thousand to 3.4 parts per thousand, show that the sulfur has a homogeneous source with characteristics of magmatic sulfur. The Pb isotopic compositions of sulfides indicate that ore-forming metal materials were derived from the mantle and ancient crust. The granodiorite porphyry displays high SiO2 (68.78%-69.75%) and K2O (3.40%-3.56%) contents, and relatively lower Cr (2.4x10(-6) -4.09x10(-6) ), Ni (2.79x10(-6)-3.58x10(-6)) contents, and positive epsilon(Hf)(t) values (7.7-12.9) indicating that the mineralization porphyry was derived from the partial melting of juvenile lower crust. The Tuolangla deposit is located in the central part of Zedang terrane. This terrane was once considered an ancient terrane. This terrane is in tectonic contact with Cretaceous ophiolitic rocks to its south and Mesozoic continental margin arc volcanics and intrusions of the Gangdese batholith of the Lhasa terrane to its north. Thus, the authors proposed that the Oligocene porphyry skarn Cu-W-Mo mineralization is probably associated with the Zedang terrane. This finding may clarify why the Oligocene (about 23 Ma) deposits are found only in the Zedang area and why mineralization types of the Oligocene mineralization are considerably different from those of the Miocene (17-14 Ma) mineralization. (C) 2020 China Geology Editorial Office
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