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Showing 1 to 20 of 44 for “"Anharmonicity"”.
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Anharmonicity in NaCl and beta brass
Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-05-31T16:51:19Z No. of bitstreams: 1 1966_swartz.pdf: 2583055 bytes, checksum: df05144e6d301fb8165650f9eb6fb5d0 (MD5)
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Optimizing coherence and anharmonicity of superconducting qubit
… of the thesis is to analyze the tradeoff between anharmonicity and dephasing in a qubit unimon. Recently developed unimon incorporates a single Josephson junction shunted by a linear inductor and a capacitor. Unimon is tunable by external magnetic flux, and at the half flux quantum bias, the …
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Anharmonicity in Sodium-Chloride and Beta-Brass
Made available in DSpace on 2015-05-12T21:41:39Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 6706750.PDF: 2356028 bytes, checksum: 5466d21831519d9edf3b33562f4b7f03 (MD5) Previous issue date: 1966
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Lattice anharmonicity in alkali-graphite intercalation compounds
Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-03T17:46:52Z No. of bitstreams: 1 1985_hardcastle.pdf: 3045662 bytes, checksum: 2aa3c0674c38dbfb86a2a1d97f93f80e (MD5)
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Infrared Frequency Shifting in Thermally- and Mechanically-Stressed Polymers (Anharmonicity, Nonequilibrium, Ftir, Fourier, Transform, Spectrometer)
Thermal and mechanical stresses alter the spacing of the constituents of a polymer chain, usually resulting in the reduction of the molecular vibration frequency as revealed by the transmission infrared spectroscopy of stressed polymer films. The effect of stress and temperature on infrared …
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X-ray scattering and lattice dynamics studies for impurity effects on the para-to-ferroelectric phase transformation behavior in lead titanate and barium titanate
… transition in terms of lattice harmonicity and anharmonicity including the creation of the defect energy. Its role in the para-to-ferroelectric transition has been investigated on two prototypical perovskite ferroelectrics, PbTiO$\sb3$ and BaTiO$\sb3.$
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Lattice Dynamics in Temperature-driven and Photo-induced Phase Transitions
… to explain the observed effects of phonon anharmonicity without using first-principles calculations, for instance to obtain renormalized second- order and higher-order force-constants. Moreover, pump-probe experiments can now resolved femtosecond atomic dynamics by using an ultrafast laser …
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Theoretical studies of compressed xenon oxides, tin selenide thermoelectrics, and defects in graphene
… to investigate the effects of nuclear motion and anharmonicity in crystal systems, which involves a local exploration of the Born-Oppenheimer energy surface. The AIRSS crystal structure prediction method is here applied to a study of defect structures in graphene. It is also applied to a study of …
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The origin and behaviour of carbonate minerals in diverse environments: from subduction zones to asteroids
… followed by volcanic outgassing. Here, the anharmonicity and solubility of carbonates and associated metal speciation was assessed under subduction zone conditions by different in situ methods. In order to understand the anharmonicity of carbonates, the high-pressure and high-temperature …
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Calculation of thermodynamic properties of gas mixtures at high temperatures
… species, accurate evaluations of vibrational anharmonicity, vibration-rotation interaction, and rotational stretching corrections are carried out. Comparisons are made between results with and without the above corrections.
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Infrared Laser Excitation and Fluorescence Spectra: A Study of Intramolecular Vibrational Energy Relaxation
… in threshold densities reflects variations in anharmonicity. For some molecules true relaxed (non C-H stretch) fluorescence is observed.
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Thermal transport across interfaces with molecular layers
… to the vibrational spectrum of Au; and that anharmonicity does not significantly contribute to the heat transport in this system.
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Vibrational many-body methods for molecules and extended systems
… developed that can account for the effects of anharmonicity in the potential energy surfaces (PESs) on energies and other observable properties. For molecules, we present a general scheme to calculate anharmonic vibrational frequencies and vibrationally-averaged structures along with …
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Probing Solvation Shell Dynamics of Organometallic Complexes via Two-Dimensional Infrared Spectroscopy
… which had the fastest rates, had the largest anharmonicity, suggesting stronger vibrational coupling. The trend in anharmonicity also coincides with the relative angles and distances between axial carbonyls. Lastly, I performed pump-probe spectroscopy on phenyl selenocyanate (PhSeCN) in four …
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Quantum Resonant Beats and Revivals in the Morse Oscillators and Rotors
… period. Within the fundamental period, the anharmonicity of this oscillator appeared to cause interesting space-time phenomena that include relatively simple Farey-sum revival structures. In addition, a simple sum of two Morse oscillators led to a double-Morse well whose geometric symmetry …
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Towards routine modelling of condensed phases with the accuracy of quantum Diffusion Monte Carlo
… and pharmaceutical systems, incorporating anharmonicity and nuclear quantum effects. In summary, this thesis presents a robust and comprehensive framework for accurately and efficiently modelling molecular crystals, marking an important step toward routine, reliable computational approaches …
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Quantum-classical correspondence in response theory
… and is shown to be inversely proportional to anharmonicity. The effects of dissipation on the correspondence between classical and quantum response functions are studied. The quantum-classical correspondence is shown to improve if coupling to the environment is introduced. In the last part of …
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Raman scattering in heavy rare earth metals
… dependence cannot be explained by lattice anharmonicity and the related volume change. The hardening of this mode may be due in part to the coupling of the TO phonon to the ordered magnetic moments. The linewidth of this mode is observed to increase at low temperature in Dy and Er. This may …
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A tale of coupled vibrations in solution told by coherent two-dimensional infrared spectroscopy
… moments in the molecular frame, the electrical anharmonicity of the system, and the vibrational relaxation dynamics. The 2D line shapes are sensitive to the complicated system-bath interactions in solution. 2D IR spectra taken with varying polarization conditions and as a function of a variable …
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Dynamics of impurities and trapped Bose-Einstein Condensates
… by the interplay between non-linearities due to anharmonicity and non-linearities due to interactions. In the case of polaritons, we make comparison with experimentally observed features, and gain an understanding of the thermalisation process in such systems.
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