Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 42 for “"Ultrafast Dynamics"”.
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Ultrafast dynamics of [NiFe] hydrogenase models
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-05-01
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Ultrafast dynamics of Fullerene thin films
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.
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Ultrafast Dynamics and Interactions During Growth at Surfaces
… technique capable of studying nanoscopic surface dynamics in thermal equilibrium. The energy resolution, which greatly exceeds that of alternative methods, makes it possible to probe motion on picosecond to nanosecond timescales. The present thesis is concerned with 3HeSE measurements and …
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Ultrafast Dynamics in Quasi-One-Dimensional Organic Molecular Crystals
Der erste Teil der Arbeit beschäftigt sich mit ultraschnellen Relaxationsprozessen in quasi-eindimensionalen organischen Molekülkristallen. Als Modellsystem wird das Perylenderivat MePTCDI untersucht. Mit verschiedenen Methoden der optischen Ultrakurzzeit-Spektroskopie werden Prozesse der …
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Ultrafast Dynamics of Flavin Cofactor in Photolyase/Cryptochrome Family
… presents a systematic investigation on the ultrafast dynamics of flavin cofactor in four redox states in photolyase/cryptochrome family proteins. In photolyase, the antenna molecule MTHF absorbs a photon and transfer the excitation energy to the catalytic cofactor FADH¯ to enhance the …
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Ultrafast Dynamics of Individual Air-Suspended Single-Walled Carbon Nanotube
… allows us to study the intrinsic exciton dynamics of a SWCNT. To gain insight into exciton nonlinear decay processes, PL saturation in pump power dependence measurement is investigated and compared to the simulated results from stochastic models of exciton dynamics. Femtosecond excitation …
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Ultrafast Dynamics and Nonlinear Interactions in Alkali Atoms and Diatomics
Ultrafast laser pump-probe techniques have been used to study the rovibrational dynamics of the B, C, and D states of the Cesium dimer and to study atomic wavepackets and nonlinear effects in Rubidium and Potassium. Two color, pump-probe techniques have been used to probe the time evolution of …
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Ultrafast dynamics of molecular liquids investigated by femtosecond light scattering
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1990.
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ULTRAFAST DYNAMICS IN NITRO- AND (ORGANOPHOSPHINE)GOLD(I)-POLYCYCLIC AROMATIC HYDROCARBONS
… The population of the triplet states occurs ultrafast, with lifetimes in the hundreds of femtoseconds in most cases. Kinetic mechanisms explaining the excited-state dynamics and photochemistry of these molecules are proposed. The experimental findings are reinforced with ground- and …
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Ultrafast dynamics in quantum materials probed by time-and-momentum-resolved techniques
… utilizing several multi-resolution techniques. Ultrafast electron diffraction (UED) and time-and-angle-resolved photoemission spectroscopy (trARPES) are tools that I co-developed with my colleagues at MIT in the past several years. Supplemented by the time-resolved X-ray diffraction (trXRD) …
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The study of ultrafast dynamics behind a solid-state shock front using optical nanogauges
Photothermal laser ablation is studied using poly-(methyl methacrylate) films doped with a dye, IR-165, which functions as a molecular heater and thermometer. Direct optical measurements of temperature are performed on samples heated by 100 ns near-IR pulses at 1.064 $\mu\rm m,$ at rates dT/dt …
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Frequency-resolved ultrafast dynamics of phonon polariton wavepackets in the ferroelectric crystals LiNbO₃ and LiTaO₃
… wavepackets of phonon polaritons. Thus, the dynamics of these wavepackets was separately studied. Based on these findings, I develop the mathematical description of the so-called homodyne detection of light for the case of light scattering from counter propagating phonon polaritons. Further, …
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The impact of iron concentration on strontium titanate oxide materials as shown through ultrafast dynamics
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-05-01
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Probing the Ultrafast Dynamics of Higher-Lying Excited States of Molecular Switches with Femtosecond Stimulated Raman Spectroscopy
… critical role in the optical control of reaction dynamics and product yield of many photoactive molecular systems. However, due to their short lifetimes and high density of states, the initial dynamics and molecular motions within the upper states is less understood. In this dissertation, the …
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Development and Construction of a new Photoelectron Imaging Spectrometer for Studying the Spectroscopy and Ultrafast Dynamics of Molecular Anions
… new experiment for studying the spectroscopy and ultrafast dynamics of molecular anions in the gas phase. The new instrument incorporates: an electrospray ionisation source, which is capable of generating a vast class of molecular anions; a Wiley-McLaren time-of-flight mass spectrometer; and a …
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Ultrafast dynamics in complex molecular solids: Ultrafast imaging of laser ablation of PMMA and theory of mechanical energy flow in ultrahot crystalline naphthalene
In a molecular solid, there is an ultrafast transfer of energy between the internal molecular vibrations and the external modes or lattice vibrations. Two interesting examples involving this energy transfer are presented in this thesis. First, an ultrafast imaging apparatus is constructed and used …
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Characterizing Ultrafast Equilibrium Dynamics Using Third-Order Nonlinear Mid-Infrared Spectroscopies
Characterizing equilibrium dynamics provides new insight into examining structure-function relationship in chemical reactions and understanding physical properties and processes in various systems. Third-order nonlinear mid-infrared spectroscopic techniques are powerful tools for investigating …
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Ultrafast reaction dynamics of polyatomic molecules probed by ionization
In the present work, the ultrafast dynamics of the photoinitiated electrocyclic ring-opening reactions of 1,3,5-cyclooctatriene and 7-dehydrocholesterol are investigated in a fs pump-probe experiment using ionization as the probe step. Concerning the 1,3,5-cyclooctatriene photoreaction, there are …
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Photoinduced phase transitions studied by femtosecond single-shot spectroscopy
… (NOPA) and a conventional pump-probe instrument, ultrafast dynamics of coherent lattice vibrations and photo-induced phase transitions were examined in two different systems. Ultrafast dynamics such as coherent lattice vibrations and bond softening were investigated for Bi thin films and bulk …
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