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Full-Text Articles in Physics

A New Dynamic Mechanism Of Topological Charge Creation In A Commensurate One-Dimensional Charge Density Wave Near The Contact With A Normal Metal, A. S. Rozhavsky, Yuriy V. Pershin Dr, A. S. Kovalev Dec 1997

A New Dynamic Mechanism Of Topological Charge Creation In A Commensurate One-Dimensional Charge Density Wave Near The Contact With A Normal Metal, A. S. Rozhavsky, Yuriy V. Pershin Dr, A. S. Kovalev

Faculty Publications

The dynamics of conversion of conduction electrons into topological solitons of a charge density wave (CDW) commensurability in an external electric field is investigated. A novel mechanism of initiation of a nonlinear CDW current in the vicinity of the interface between a CDW and a normal metal is revealed and explained. The nonlinear current is produced by the conduction solitons created by the moving profile of the order parameter, formed during the conversion of electrons into collective phase excitations of a CDW. The field dependence of the current is of threshold nature and has no analogs in the bulk mechanisms …


A Novel Laboratory Course On Advanced Chemical Engineering Experiments, Jochen A. Lauterbach, S. White, X. Lui, G. M. Bodner, W. N. Delgass Oct 1997

A Novel Laboratory Course On Advanced Chemical Engineering Experiments, Jochen A. Lauterbach, S. White, X. Lui, G. M. Bodner, W. N. Delgass

Faculty Publications

The chemical engineering curriculum in the United States has trained generations of technical experts who have successfully optimized chemical processes and products once they entered the chemical industry. The U.S. chemical industry, however, has entered a critical stage in which it must be able to create new and differentiated value through technical innovations that arc essential for long-term survival. This innovation process will require new skills that go far beyond the traditional expertise for the optimization of tasks possessed by young chemical engineers. The innovators must be able to identify new opportunities, explore the boundaries of technology, evaluate critical issues, …


Intrinsic Decoherence In Mesoscopic Systems, P. Mohanty, E. M.Q. Jariwala, Richard A. Webb Apr 1997

Intrinsic Decoherence In Mesoscopic Systems, P. Mohanty, E. M.Q. Jariwala, Richard A. Webb

Faculty Publications

We present measurements of the phase coherence time τφ in six quasi-1D Au wires and clearly show that τφ is temperature independent at low temperatures. We suggest that zero-point fluctuations of the phase coherent electrons are responsible for the observed saturation of τφ. We introduce a new functional form for the temperature dependence and present the results of a calculation for the saturation value of τφ. This explains the observed temperature dependence of our samples as well as many 1D and 2D systems reported to date.


Lithium Bonding Interaction In H2Cy⋯Lif (Y=O,S) Complexes: A Theoretical Probe, Salai Cheettu Ammal, P. Venuvanalingam, S. Pal Jan 1997

Lithium Bonding Interaction In H2Cy⋯Lif (Y=O,S) Complexes: A Theoretical Probe, Salai Cheettu Ammal, P. Venuvanalingam, S. Pal

Faculty Publications

Ab initio calculations at 6-31++G(d,p) level have been done on H2CY⋯LiF (Y=O,S) complexes choosing ten possible orientations in each complex. The effect of correlation on complex binding energies has been studied via single point MP2 (full) calculations done on 6-31++G(d,p) geometry. Binding energies have been corrected for basis set superposition error. Frequency calculations confirm that H2CO⋯LiF and H2CS⋯LiF complexes have three and two stable forms, respectively. The most stable form in each complex has been found to have a strong lithium bonding interaction and a secondary hydrogen bondinginteraction. NBO analysis has revealed that in this form oxygen donates nσ lone …


Semiclassical Approach To The Hydrogen-Exchange Reaction Reactive And Transition-State Dynamics, Sophya V. Garashchuk, F. Grossmann, D. Tannor Jan 1997

Semiclassical Approach To The Hydrogen-Exchange Reaction Reactive And Transition-State Dynamics, Sophya V. Garashchuk, F. Grossmann, D. Tannor

Faculty Publications

Scattering matrix elements and symmetric transition-state resonances for the collinear H 2 + H → H + H 2 reaction are obtained using a time-dependent approach. The correlation function between reactant channel wavepackets and product channel wavepackets is used to determine the S-matrix elements. In a similar fashion, autocorrelation functions are used to extract the positions and widths of transition-state resonances. The time propagation of the wavepackets is performed by the improved semiclassical frozen Gaussian method of Herman and Kluk, which is an initial value, uniformly converged method. The agreement between the quantum and semiclassical results is far better …