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51.
The paradigm tripartite efflux transporter AcrA-AcrB-TolC confers multiple drug resistance to Escherichia coli. Tikhonova et?al. (2011) now examine how the three components connect to unity and highlight the critical role of AcrA membrane proximal domain conformation for successful assembly. 相似文献
52.
Explicitly correlated coupled cluster theory at the CCSD(T)-F12x (x = a, b) level (Adler, T. B.; Knizia, G.; Werner, H.-J. J. Chem. Phys. 2007, 127, 221106) has been employed in a study of the benzenium ion (C6H7(+)) and its complexes with a neon or an argon atom. The ground-state rotational constants of C6H7(+) are predicted to be A0 = 5445 MHz, B0 = 5313 MHz, and C0 = 2731 MHz. Anharmonic vibrational wavenumbers of this cation were obtained by combination of harmonic CCSD(T*)-F12a values with anharmonic contributions calculated by double-hybrid density functional theory at the B2PLYP-D level. For the complexes of C6H7(+) with Ne or Ar, the lowest energy minimum is of π-bonded structure. The corresponding dissociation energies D0 are estimated to be 160 and 550 cm(-1), respectively. There is no indication of H-bonds to the aromatic or aliphatic hydrogen atoms. Instead, three nonequivalent local energy minima were found for nuclear configurations where the rare-gas atom lies in the ring-plane and approximatly points to the center of one of the six CC bonds. 相似文献
53.
Oswald S Mikhailova D Scheiba F Reichel P Fiedler A Ehrenberg H 《Analytical and bioanalytical chemistry》2011,400(3):691-696
For future Li-ion battery applications the search for both new design concepts and materials is necessary. The electrodes
of the batteries are always in contact with electrolytes, which are responsible for the transport of Li ions during the charging
and discharging process. A broad range of materials is considered for both electrolytes and electrodes so that very different
chemical interactions between them can occur, while good cycling behavior can only be obtained for stable solid-electrolyte
interfaces. X-ray photoelectron spectroscopy (XPS) was used to study the most relevant interactions between various electrode
materials in contact with different electrolyte solutions. It is shown how XPS can provide useful information on reactivities
and thus preselect suitable electrode/electrolyte combinations, prior to electrochemical performance tests. 相似文献
54.
Explicitly correlated coupled cluster theory at the CCSD(T)-F12x (x = a, b) level [T. B. Adler et al., J. Chem. Phys. 127, 221106 (2007)] has been employed in a study of the potential energy surfaces for the complexes H(2)C(3)H(+) · Ar and c-C(3)H(3)(+) · Ar. For the former complex, a pronounced minimum with C(s) symmetry was found (D(e) ≈ 780 cm(-1)), well below the local "H-bound" minimum with C(2v) symmetry (D(e) ≈ 585 cm(-1)). The absorption at 3238 cm(-1) found in the recent infrared photodissociation spectra [A. M. Ricks et al., J. Chem. Phys. 132, 051101 (2010)] is, thus, interpreted as an essentially free acetylenic CH stretching vibration of the propargyl cation. A global minimum of C(s) symmetry was also obtained for c-C(3)H(3)(+) (D(e) ≈ 580 cm(-1)), but the energy difference with respect to the local C(2v) minimum is only 54 cm(-1). 相似文献
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56.
J. Šonský J. Lančok M. Jelínek J. Oswald V. Studnička 《Applied Physics A: Materials Science & Processing》1998,66(5):583-586
3 (YAP) thin films as a promising material for application in a planar waveguide laser has been studied. The films have been
grown on sapphire(0001) and YAP(001) substrates by laser ablation. The influence of the substrate temperature and ambient
oxygen pressure on the crystalline structure, concentration of Nd incorporated into films, and consequent luminescence spectra
were investigated. The waveguiding properties were observed and refractive index of the films was evaluated.
Received: 8 February 1998/Accepted: 9 February 1998 相似文献
57.
58.
Peter Oswald. 《Mathematics of Computation》1996,65(215):923-941
We prove an abstract norm equivalence for a two-level method, which allows us to reduce the construction of preconditioners for nonconforming finite element discretizations to known cases of conforming elements.
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60.