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排序方式: 共有372条查询结果,搜索用时 15 毫秒
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Shilton JM Talyanskii VI Pepper M Ritchie DA Frost JE Ford CJ Smith CG Jones GA 《J Phys Condens Matter》1996,8(38):L531-L539
We report on an experimental investigation of the direct current induced by transmitting a surface acoustic wave (SAW) with frequency 2.7 GHz through a quasi-one-dimensional (1D) channel defined in a GaAs - AlGaAs heterostructure by a split gate, when the SAW wavelength was approximately equal to the channel length. At low SAW power levels the current reveals oscillatory behaviour as a function of the gate voltage with maxima between the plateaux of quantized 1D conductance. At high SAW power levels, an acoustoelectric current was observed at gate voltages beyond pinch-off. In this region the current displays a step-like behaviour as a function of the gate voltage (or of the SAW power) with the magnitude corresponding to the transfer of one electron per SAW cycle. We interpret this as due to trapping of electrons in the moving SAW-induced potential minima with the number of electrons in each minimum being controlled by the electron - electron interactions. As the number of electrons is reduced, the classical Coulomb charging energy becomes the Mott - Hubbard gap between two electrons and finally the system becomes a sliding Mott insulator with one electron in each well. 相似文献
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James P. Ritchie 《Tetrahedron letters》1982,23(48):4999-5002
Vibrational frequency calculations at the 6–31G*, 6–31G and STO-3G levels in addition to an STO-3G basis set with only a 1s orbital on lithium reveal that both bridged and linear dilithioacetylenes are minima on the potential energy surface. 相似文献
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B. Ormsby G. Foster T. Learner S. Ritchie M. Schilling 《Journal of Thermal Analysis and Calorimetry》2007,90(2):503-508
After improvements were made to a modified Polymer Labs MkIII DMTA instrument to facilitate repeatable controlled humidity
(RH) experiments using isothermal and thermal scanning conditions, the viscoelastic properties of titanium white pigmented
artists’ acrylic emulsion films were measured in tensile mode. The effects of temperature, relative humidity and accelerated
ageing regimes on two brands of titanium white paints were explored. These paints are highly responsive to changes in temperature
and relative humidity, formulation differences affect properties slightly, and while light ageing had a negligible effect,
thermal ageing resulted in decreased storage modulus and increased film density. 相似文献