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1. chinaXiv:201705.00413 [pdf]

Understanding the unusual friction behavior of hydrogen-free diamond-like carbon films in oxygen atmosphere by first-principles calculations

Wang, LP [Wang, Liping][ 1,3 ]; Cui, LC [Cui, Longchen][ 2,3 ]; Lu, ZB [Lu, Zhibin][ 3 ]; Zhou, H [Zhou, Hui][ 2 ]
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

The friction coefficients of diamond and hydrogen-free diamond-like carbon films were reported to be in an intermediate range, from 0.2 to 0.4, in oxygen atmosphere, but the mechanism has not been explored. Herein, by using first-principles calculations, we attempt to fill this gap by providing atomistic insights into the bonding behaviors of oxygen atom(s) at interfaces constructed by two self-mated diamond (001) or (111) surfaces. The effect of the interfacial oxygen coverage on the optimized interfacial structures is highlighted. The results show that if the oxygen coverage is not higher than 0.5, the two surfaces tend to be connected by oxygen atoms by formation of CeOeC bonds, and thus high friction is expected. Otherwise, the two surfaces keep being separated, and thus low friction is expected. The interfacial electron distributions are manifested to underlie the structural optimizations. Insights gained here together with the findings of T. E. Derry et al. concerning oxygen coverage on diamond surfaces contribute to understanding the unusual frictional behavior of hydrogen-free diamond-like carbons in oxygen atmosphere.

submitted time 2017-05-02 Hits578Downloads341 Comment 0

2. chinaXiv:201612.00391 [pdf]

Strong supersymmetric quantum effects on top quark production at the Fermilab Tevatron

Li,C; Zhou,H; Zhu,Y; Yang,J
Subjects:

The supersymmetric QCD corrections to top quark pair production by qq ? anni- hilation in pp ? collisions are calculated in the minimal supersymmetric model. We consider effects of the mixing of the scalar top quarks on the corrections to the total tt ?production cross section at the Fermilab Tevatron. We found that such correction is less sensitive to squark mass and gluino mass than in no-mixing case, and in both cases the corrections can exceed 10% even if we consider the recent CDF limit on squark and gluino masses.

submitted time 2016-12-28 Hits1197Downloads659 Comment 0

3. chinaXiv:201612.00389 [pdf]

Yukawa corrections to top pair production in photon-photon collision

Li,C; Yang,J; Zhu,Y; Zhou,H
Subjects:

The O(αmt 2/mW 2)O(αmt 2/mW 2)O(\alpha m_t~2/m_W~2) Yukawa corrections to top pair production in photon-photon collision are calculated in the standard model (SM), the general two-Higgs-doublet model (2HDM) as well as the minimal supersymmetric model (MSS

submitted time 2016-12-28 Hits1114Downloads612 Comment 0

4. chinaXiv:201612.00382 [pdf]

Supersymmetric QCD corrections to single top quark production at the Fermilab Tevatron

Li,C; Oakes,RJ; Yang,J; Zhou,H
Subjects:

We evaluate the supersymmetric QCD corrections to single top quark production via qq?′→tb?qq?′→tb?q \bar q'\to t \bar b at the Fermilab Tevatron in the minimal supersymmetric model. We find that within the allowed range of squark and gluino masses the sup

submitted time 2016-12-28 Hits1321Downloads752 Comment 0

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