244 research outputs found

    Erratum to: The hyperfine excitation of OH radicals by He

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    Hyperfine-resolved collisions between OH radicals and He atoms are investigated using quantum scattering calculations and the most recent ab initio potential energy surface, which explicitly takes into account the OH vibrational motion. Such collisions play an important role in astrophysics, in particular in the modelling of OH masers. The hyperfine-resolved collision cross sections are calculated for collision energies up to 2500 cm-1 from the nuclear spin free scattering S-matrices using a recoupling technique. The collisional hyperfine propensities observed are discussed. As expected, the results from our work suggest that there is a propensity for collisions with ΔF = Δj. The new OH−He hyperfine cross sections are expected to significantly help in the modelling of OH masers from current and future astronomical observations

    Family enterprise and technological innovation

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    Family enterprises in China have significant impact on China’s social and economic development. Yet did technological innovation in Chinese family enterprise play a role on this impact? We examine the role that technology innovation played in the rise in importance of Chinese family businesses. We analyze the impact of family enterprises on companies’ technological innovation through both family ownership and family management involvement. We further scrutinize how Chinese family-owned business internationalization strategies affected their technological innovation activities. The authors show that family ownership without family management involvement has a negative relations with companies’ technical innovation. We further demonstrate that family ownerships with family management involvement have a positive relations with enterprises’ technical innovation. Our study provides some effective measures to increase the investment in firms’ technical innovation and minimize the disadvantages of family business. The research result has practical significance in the governance of family enterprises

    Collisional excitation of CH(X-2 Pi) by He: new ab initio potential energy surfaces and scattering calculations

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    S.M. and F.L. greatly acknowledge the financial support of ANR project ‘HYDRIDES’. This research utilized Queen Mary's MidPlus computational facilities, supported by QMUL Research-IT and funded by EPSRC grant EP/K000128/1. J.K. acknowledges the financial support by the National Science Foundation Grant No. CHE-121333

    Collisional excitation of interstellar PO(X-2 Pi) by He: new ab initio potential energy surfaces and scattering calculations

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    We acknowledge the financial support from the COST Action CM1401 “Our Astrochemical History”. This research utilized Queen Mary's Mid-Plus computational facilities, supported by QMUL Research-IT and funded by EPSRC grant EP/K000128/1. S. M. acknowledges Indigo Dean for very useful discussions. I. J.-S. acknowledges the financial support received from the STFC through an Ernest Rutherford Fellowship (proposal number ST/L004801)

    A study of Ar-N₂ supercritical mixtures using neutron scattering, molecular dynamics simulations and quantum mechanical scattering calculations

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    The microscopic structure of Ar-N₂ supercritical mixtures was obtained using neutron scattering experiments at temperatures between 128.4 - 154.1 K, pressures between 48.7 - 97.8 bar and various mole fractions. Molecular Dynamics simulations (MD) were used to study the thermodynamics, microscopic structure and single molecule dynamics at the same conditions. The agreement between experimental and theoretical results on the intermolecular structure was very good. Furthermore, a new explicitly-correlated coupled cluster potential energy surface was obtained for the Ar-N₂ van der Waals complex. The ab initio potential energy surface (PES) was found in agreement with the MD interaction potential. The global minimum of the ab initio PES Dₑ = 98.66 cm⁻¹ was located at the T-shaped geometry and at the intermolecular equilibrium distance of Rₑ = 7.00a₀. The dissociation energy of the complex was determined to be D₀ = 76.86 cm⁻¹. Quantum mechanical (QM) calculations on the newly obtained PES were used to provide the bound levels of the complex. Finally, integral and differential QM cross sections in Ar + N₂ collisions were calculated at collision energy corresponding to the average temperature of the experiments and at room temperature

    Microscopic Structure of Liquid Nitric Oxide

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    The microscopic structure of nitric oxide is investigated using neutron scattering experiments. The measurements are performed at various temperatures between 120 and 144 K and at pressures between 1.1 and 9 bar. Using the technique of empirical potential structure refinement (EPSR), our results show that the dimer is the main form, around 80%, of nitric oxide in the liquid phase at 120 K, but the degree of dissociation to monomers increases with increasing temperature. The reported degree of dissociation of dimers, and its trend with increasing temperature, is consistent with earlier measurements and studies. It is also shown that nonplanar dimers are not inconsistent with the diffraction data and that the possibility of nitric oxide molecules forming longer oligomers, consisting of bonded nitrogen atoms along the backbone, cannot be ruled out in the liquid. A molecular dynamics simulation is used to compare the present EPSR simulations with an earlier proposed intermolecular potential for the liquid

    An investigation of thermodynamics, microscopic structure, depolarized Rayleigh scattering, and collision dynamics in Xe-N-2 supercritical mixtures

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    We would like to dedicate this work to the late Professor W. A. Steele (W.A.S.), Penn State University, USA. NATO Research-Project SA 5-2-05(CRG 950087) JARC (97) 288 is acknowledged for project funding to J.S., H.V. and W.A.S. The Greek State Scholarships Foundation (IKY) is acknowledged for an award based on performance to S. M. This work was supported by computational time granted from the Greek Research & Technology Network (GRNET) in the National HPC facility ARIS. The CPU time of the Computing Centre of the University of Athens (Greece) is gratefully acknowledged. This research utilized Queen Mary’s Mid-Plus computational facilities, supported by QMUL Research-IT and funded by EPSRC grant EP/K000128/1. J.K. acknowledges financial support from the NSF Grant No. CHE-1565872 to Millard Alexander
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