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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 17 of 17 for “"Electron attachment"”.
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Electron Attachment To Small Molecular Clusters
A large number of secondary electrons with low energies (< 20 eV) is produced during irradiation of biological matter. It is known that such electrons lead to fragmentation of DNA via dissociative electron attachment (DEA). DEA happens via the formation of a resonance (transient negative ion). …
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Low energy electron attachment to buckminsterfullerene in Rydberg atom-buckminsterfullerene collisions
… $\rm35\leq n\leq125,$ which corresponds to electrons with mean energies in the range $\sim$2 meV to $\sim$170 $\mu$eV, and $C\sb{60}$ molecules. This results from Rydberg electron transfer and has permitted study of the low energy electron attachment properties of Buckminsterfullerene, which …
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CHARACTERIZATION OF BCl₃, SF₆, and BCl₃/SF₆ PLASMAS USING LANGMUIR PROBE MEASUREMENTS
… In this study, energy distribution functions, electron temperatures (and average electron energy) and electron, positive ion, and negative ion densities were determined as a function of process conditions such as RF power, chamber pressure, and SF6 percentage in the total flow. With the …
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A STUDY OF LOW ENERGY ELECTRON-MOLECULE AND ION-MOLECULE COLLISIONS USING RYDBERG ATOMS (IONIZATION, ASSOCIATION, ATTACHMENT, OXYGEN, WATER)
… The results have been used to validate the free-electron, independent particle model of Rydberg atom collisions. Comparison between theory and experiment show that at large values of n, ionization of Rb(nS,nD) Rydberg atoms in the reaction: (UNFORMATTED TABLE FOLLOWS) Rb(nS,nD) + SF(,6) (--->) …
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Ionisation studies of chlorinated and fluorinated compounds
… molecules have been studied using threshold photoelectron photoion coincidence and selected ion flow tube techniques for cations and an electron attachment mass spectrometer for anions. Cation formation has been studied for fluoroform (CHF\(_3\)), octafluorocyclobutane (\(c\)-C\(_4\)F\(_8\)), …
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Low-energy electron diffraction effects at complex interfaces
Low-energy electron scattering was used as a tool to study electron-stimulated processes at complex interfaces. The electron diffraction in each complex interface is theoretically treated by a multiple scattering formalism for quantitative analysis. Mathematical descriptions of electron-stimulated …
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Tddft Derivative Couplings And Other Topics In Quantum Chemistry
… which involve both the ground and excited electronic states of a molecule, can promote processes otherwise inaccessible by normal reactions. In general, photochemical reactions may be classified as adiabatic or nonadiabatic depending on whether the reaction takes place on the same adiabatic …
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Fourier spectral methods for numerical modeling of ionospheric processes
… density depletion (due to late times effects of electron attachment material releases) in the presence of a neutral wind. The evolution of the irregularities is monitored and discussed. The simulation results agree with similar results obtained using finite difference methods. A comparison is …
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Etude par Spectrométrie de Masse de la formation d'Ions Négatifs par Attachement Electronique Dissociatif et par le processus de Paire d'Ions.
… ions by both the mechanism of Dissociative Electron Attachment (DEA) and Ion Pair processes (IPP) by electron impact. Using the appropriate instrumentation (a conventional Nier type mass spectrometer) the best conditions are chosen to ensure ion-molecule collision free ion production (sample …
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Conformational behaviour of selected silicon- and germanium-containing ring systems
… temperature-dependent Raman spectroscopy and gas electron diffraction (GED). Attempts to observe directly the axial and equatorial conformers by freezing the inversion on the NMR time scale failed because of the low barrier for inversion and the flexibility of the compounds. The …
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Positronium formation in organic liquids and studies of micelle, liposome and polymer systems by position annihilation technique
… nuclear decay process (β+) can interact with an electron resulting in a positronium formation (Ps). In the first part of this thesis the formation of positronium in benzene solutions containing various halogenated compounds was studied in the presence and absence of C₆F₆ additives. The observed …
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Improved mass spectrometry characterization of organic compounds using analyte preconcentration and radio-frequency ionization.
… ionization technique. The possibility of electron emission in RFI, using both direct charged particle current measurements and indirect electron detection, was also studied. We show that RF-generated electrons can be captured by high electron affinity molecules (e.g., hexafluorobenzene) in …
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UV Induced Processes in Biomolecules, Hydrated Clusters and Stark Deflected Beams
… of isolated and clustered nucleobases in neutral electronic excited states and ionic states. Furthermore, it presents a new <i>laser thermal desorption</i> facility and reports advances in applying <i>Stark deflection</i> to narrow the range of molecular and cluster configurations in continuous …
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Generation and Characterization of Energetic Neutral Beams for Surface Modification
… and plasma imaging was used to study the electron temperature, electron density and electromagnetic structure in the capacitive and inductive modes of operation. Measured average energies in the tail of the electron energy distribution function ranged between 7 and 9 eV in a pressure range …
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Interaction of the potential DNA-radiosensitizer 8-bromoadenine with free and plasmonically generated electrons
… to their interaction with secondary low energy electrons (LEEs) that are generated along the track of the ionizing radiation. In the therapy of cancer DNA is an important target, as severe DNA damage like double strand breaks induce the cell death. As there is only a limited number of …
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Photoelectron Imaging of Iodide Centered Alkyl Halide Cluster Anions
… iodide anion as a means of investigating electron molecule interaction. Due to the localization of the excess charge on the iodine atom, these experiments proceed analogously to electron scattering experiments, in that exposure to sufficient photon energy detaches the electron, which may …
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Thermal and electron stimulated chemistry of complex adsorbates on metal surfaces
… Mo(IV) oxide “shell” which encapsulates two electronically active pyramidal sulfite (SIVO32-) groups, and has the ability to reversibly interconvert between two electronic states. In the passive state, at cryogenic temperatures (77 K), the two SO32- groups are non-bonding with respect to the …