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151.
Evi Vinck Damien M. Murphy Ian A. Fallis Sabine Van Doorslaer 《Applied magnetic resonance》2010,37(1-4):289-303
We recently demonstrated how the aerobic addition of acetic acid to N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexane-diamino CoII, [Co(1)], leads to the formation of an unusual coordinated CoIII-phenoxyl radical. In this work, some of the structural aspects associated with the Schiff-base-derived ligand (1) that are crucial for the acid-mediated formation of the phenoxyl radical are investigated. For comparison with [Co(1)], we therefore studied the influence of acetic acid on two complexes: (1) the N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-ethane-diamino CoII complex, [Co(2)], that lacks the cyclohexyl group of [Co(1)], and (2) the N′-disalicylidene-ethylenediamine CoII salen complex, [Co(3)], that lacks both the tertiary butyl groups and the cyclohexyl groups. It is shown that the cyclohexyl group of [Co(1)] is not involved in the formation or stabilization of the phenoxyl radical, whereas the tertiary butyl groups of [Co(1)] play a crucial role. In addition, the characteristics of the phenoxyl radical, formed after aerobic addition of acetic acid to [Co(2)], are analyzed in detail by pulsed electron paramagnetic resonance, in combination with isotopic labeling. The experimental data are compared to density functional theory computations and to previous data on the acid-mediated phenoxyl radical of [Co(1)]. 相似文献
152.
A new type of semi-active hydraulic engine mount using controllable area of inertia track 总被引:1,自引:0,他引:1
Thanh Quoc Truong 《Journal of sound and vibration》2010,329(3):247-4446
Automotive engine mounts function to constrain the engine shake motion resulting at low-frequencies, as well as to isolate noises and vibrations generated by the engine with unbalanced disturbances at the high frequencies. The property of the mount depends on vibration amplitude and excitation frequency. It means that the excitation amplitude is large in low excitation frequency range and small in high frequency range. In this paper, a new hydraulic engine mount with a controllable area of inertia track is proposed and investigated. Theoretical works with the mount model to isolate the engine-related vibrations were conducted by an optimal algorithm to control the area of the inertia track under shocks and multi-signal force excitations. This research clearly gives an analysis of the considerable changes in the mount dynamic properties according to the changes in the inertia track area. Consequently, when the inertia track area is tuned, the transmissibility of the mount is effectively reduced. 相似文献
153.
154.
I. V. Ajinenko Y. A. Belokopitov A. A. Borovikov P. V. Chliapnikov Z. C. Garutchava L. N. Gerdyukov S. A. Gumenuk V. V. Kniazev A. I. Kurnosenko L. V. Orekhova L. P. Petrovikh V. N. Riadovikov A. G. Tomaradse V. A. Uvarov A. P. Vorobjev N. S. Amaglobely Ch. S. Chochiachvili M. Barth E. A. De Wolf M. Van Immerseel F. Verbeure CERN - USSR Collaboration 《Zeitschrift fur Physik C Particles and Fields》1984,25(2):103-114
We present final results on inclusive production ofK *+(890),K *+(1430) andK *?(890) in \(\bar K^ + p\) interactions at 32 GeV/c, based on a statistics of ~27 events/μb. Total cross sections,p T -andx-dependence of inclusive distributions are compared with experiments at other energies and with the Lund fragmentation model. Spin density matrix elements of theK *+(890) are also discussed. The results suggest that “recombination” of both initial state valence quarks \(\bar s\) andu of theK + intoK *+(890), responsible in the Lund model for ~45% of theK *+(890) cross section, is strongly suppressed. 相似文献
155.
M. Barth E. A. De Wolf P. Theocharopoulos H. Drevermann Y. Goldschmidt-Clermont M. Spyropoulou-Stassinaki R. T. Ross G. Vassiliadis C. Caso R. Contri F. Fontanelli J. F. Baland J. Beaufays F. Grard L. Gatignon A. Stergiou R. T. Van de Walle P. V. Chliappnikov A. B. Fenyuk L. N. Gerdyukov I. A. Gritsaenko T. C. Makharadze V. I. Nikolaenko Y. L. Petrovikh V. M. Ronjin 《Zeitschrift fur Physik C Particles and Fields》1984,22(1):23-31
Inclusive and semi-inclusive cross sections and distributions of γ's and π0's inK + p interactions at 70 GeV/c are presented. The results are compared to other experiments and to the Lund model for low-p T hadron collisions. 相似文献
156.
Kevin M. Dunn Péter Pulay Christian Van Alsenoy James E. Boggs 《Journal of Molecular Spectroscopy》1984,103(2):268-280
The geometry, complete harmonic force field, and dipole moment derivatives of cubane, C8H8, have been calculated at the Hartree-Fock level using a 4–21 Gaussian basis set. The infrared and Raman spectra of cubane and four deuterated derivatives were calculated and compared with previously observed spectra. A set of five scale factors for the calculated force constants was then derived by least-squares fitting of the fundamental vibrational frequencies calculated from the scaled force field to the frequencies obtained by direct experimental measurement. The resulting scaled quantum-mechanical (SQM) force field, containing 73 unique elements, is believed to give an accurate representation of the harmonic vibrational potential of cubane. In most cases, the spectral assignments previously made from purely empirical considerations were confirmed, but a few corrections are proposed. The only major alteration is for an A2u mode revised to appear at 1030 cm?1 in the undeuterated molecule. Coriolis constants and approximate infrared intensities are also calculated. 相似文献
157.
158.
M. Van Hove G. Borghs P. De Bisschop R. E. Silverans 《Zeitschrift für Physik A Hadrons and Nuclei》1985,321(2):215-219
The hyperfine structure of the metastable 5d 2 D 3/2 state has been measured with high precision by collinear laser-rf double resonance spectroscopy on fast135,137Ba ion beams. The present data are about 100 times more accurate than those obtained by classical fast beam laser spectroscopy. 相似文献
159.
Nonlinear Elastic Wave Spectroscopy (NEWS) relies on the activation of defects by wave energy that propagates through the medium. In general, the response of activated defects will not scale linearly with the excitation amplitude, and the resulting nonlinear signatures can be identified and used for quality inspection. The efficiency of NEWS based inspection methods is therefore intrinsically linked to the locally deposited activation energy at the defect zone and the ability to generate nonlinear signatures that exceed the noise level of acquisition. Time Reversal techniques allow focusing of high levels of energy in small areas, and are consequently very useful for the local activation of defected zones. In this report, numerical simulations are reported showing the potential of a combination consisting of dual energy reciprocal Time Reversal and nonlinearity filtering using the Scaling Subtraction Method. The method is applied to the detection of planar near-surface defects parallel to the surface in a 2D domain. The results are evaluated for sweep excitation at different frequency ranges; for point-like receiver as well as extended transducers, and for in-plane as well as out-of-plane focusing. The observable nonlinear response at the surface is linked to an effective nonlinearity within the medium based on the defect geometry and the distribution of the local stresses. 相似文献
160.
Evelyne Van Houtte Sofie Claeys Floris Wuyts Kristiane Van Lierde 《Journal of voice》2011,25(5):570-575