Download or read book Vibrational Translational Energy Transfer in Atom Polyatomic Molecule Collisions in Thermal Reaction Systems written by I. Oref and published by . This book was released on 1977 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vibrational-translational energy transfer probabilities and collisional efficiencies are calculated for atom-polyatomic molecule collisions. It is assumed that a collision complex is formed and that the total internal vibrational energy is statistically distributed among all the modes of the complex. An attractive potential is assumed and account is taken of the centrifugal barrier. Conservation of system angular momentum is imposed. Convolution of the several thermal distribution functions is carried out and completeness and detailed balance are observed. Comparison of calculated quantum statistical quantities with experiment is made for the thermal isomerization of methyl and ethyl isocyanide in the presence of heavy atomic bath gases, such as Xe or Ar, and semiquantitative agreement is found. (Author).
Download or read book Charge and Energy Transfer Dynamics in Molecular Systems written by Volkhard May and published by John Wiley & Sons. This book was released on 2023-08-28 with total page 549 pages. Available in PDF, EPUB and Kindle. Book excerpt: Charge and Energy Transfer Dynamics in Molecular Systems Comprehensive resource offering knowledge on charge and energy transfer dynamics in molecular systems and nanostructures Charge and Energy Transfer Dynamics in Molecular Systems provides a unified description of different charge and energy transfer phenomena in molecular systems with emphasis on the theory, bridging the regimes of coherent and dissipative dynamics and thus presenting classic rate theories as well as modern treatments of ultrafast phenomena. Starting from microscopic models, the common features of the different transfer processes are highlighted, along with applications ranging from vibrational energy flow in large polyatomic molecules, the motion of protons in solution, up to the concerted dynamics of electronic and nuclear degrees of freedom in molecules and molecular aggregates. The newly revised and updated Fourth Edition contains a more detailed coverage of recent developments in density matrix theory, mixed quantum-classical methods for dynamics simulations, and a substantially expanded treatment of time-resolved spectroscopy. The book is written in an easy-to-follow style, including detailed mathematical derivations, thus making even complex concepts understandable and applicable. Charge and Energy Transfer Dynamics in Molecular Systems includes information on: Electronic and vibrational molecular states, covering molecular Schrödinger equation, Born—Oppenheimer separation and approximation, Hartree-Fock equations and other electronic structure methods Dynamics of isolated and open quantum systems, covering multidimensional wave packet dynamics, and different variants of density operator equations Interaction of molecular systems with radiation fields, covering linear and nonlinear optical response using the correlation function approach Intramolecular electronic transitions, covering optical transition and internal conversion processes Transfer processes of electrons, protons, and electronic excitation energy Providing in-depth coverage of the subject, Charge and Energy Transfer Dynamics in Molecular Systems is an essential resource for anyone working on timely problems of energy and charge transfer in physics, chemistry and biophysics as well as for all engaged in nanoscience and organic electronics.
Download or read book Data Index for Energy Transfer Collisions of Atoms and Molecules 1970 1979 written by and published by . This book was released on 1981 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1976 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book State Resolved Collisional Energy Transfer in Highly Vibrationally Excited Polyatomic Molecules written by and published by . This book was released on 1992 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transfer of energy in isolated or colliding molecules is a fundamental process with practical consequences for complex phenomena occurring in atmospheric chemistry, combustion, molecular lasers, plasmas, and a host of other environments containing energetic species. We have developed a technique that combines vibrational overtone excitation, to prepare highly vibrationally excited initial states, and time-resolved spectroscopic detection, to probe the evolution of the prepared state, for studying energy transfer in vibrationally energized molecules. We have used this approach to determine directly, for the first time, the frequencies of the three ungerade vibrations in the first electronically excited state of acetylene. Using this information we have characterized highly vibrationally excited states of acetylene and directly the frequencies and rotational constants of the perturbing vibrational states at these energies. Combining these spectroscopic insights on the vibrationally and electronically excited states of acetylene has allowed us to determine the energy transfer rates and pathways in the collisional relaxation of a polyatomic molecule containing 10,000 cm-1 of vibrational energy, Rotational energy transfer is very rapid, occurring on about every other collision, but is essentially unaffected by the identity of the vibrational state in which the rotational relaxation occurs.
Download or read book NBS Special Publication written by and published by . This book was released on 1981 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Collisional Energy Transfer in Highly Vibrationally Excited Polyatomic Molecules written by F. F. Crim and published by . This book was released on 1988 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: The three objectives of this work are to determine the nature of highly vibrationally excited polyatomic molecule, to determine the rate constants and pathways for the collisional relaxation of these molecules, and to probe the electronic spectroscopy of these molecules. We have created and implemented approaches for accomplishing these objectives and have demonstrated their feasibility by studying the collisional energy transfer in highly vibrational excited acetylene. We have found that the collisional self relaxation rates of single angular momentum states with 10,000/cm of vibrational energy are a substantial fraction of the gas kinetic collision rates. The rate constant is about a factor of two smaller for relaxation by atomic partners. Molecular energy transfer, Vibrational energy transfer. (MJM).
Download or read book The Transfer of Molecular Energies by Collision Recent Quantum Treatments written by F. A. Gianturco and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: I I These Lecture Notes are intended as an introduction to the theoretical formulation and computational aspects of the molecular energy transfer processes which take place in an increasingly sophisticated range of molecular scattering experiments. They are directed to chemistry graduate students and emphasize the quantum mechanical approach, with little or no attention to classical and semi classical treatments or to formal presentations. Several Sections of the first Chapters are based on lectures given at the Graduate School of Physics of the University of Genoa a few years ago and I thank the students for their sense of duty in following to the end all those no tation-filled blackboards and transparencies. The kind patience of my wife Carolyn in reading the whole manuscript and improving its form is gratefully acknowledged. Franco A. Gianturco Bari, September 1978 CON TEN T S FOREWORD I NTRODUCTI ON Page 1. A RESUME OF QUANTUM MECHANICAL POTENTIAL SCATTERING 1. 1. General formulation of the problem Page 5 1. 2. Solutions of the radial equation 10 " 1. 3. The method of partial waves 13 1. 4. Some properties of 61. The Born appro~imation 18 1. 5. Properties of the S-matrix: bound states and resonances 23 1. 6. Classical and semiclassical scattering,a set of defi- tions 34 References 44 2. POTENTIAL ENERGY HYPERSURFACE CALCULATIONS FOR SIMPLE SYSTEMS 2. 1. Kinematic considerations 45 2. 2. General development of a priori method 52 2. 3. Some approximate treatments 68 2. 4.
Download or read book Vibrational Energy Transfer in Polyatomic Molecules written by Sarah Margaret Anne Wright and published by . This book was released on 2000 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fiscal Year 1986 Department of Energy Authorization basic Research Programs written by United States. Congress. House. Committee on Science and Technology. Subcommittee on Energy Development and Applications and published by . This book was released on 1985 with total page 1160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research in Progress written by and published by . This book was released on 1973 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1992 with total page 1812 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lasers and Masers a Continuing Bibliography written by United States. National Aeronautics and Space Administration and published by . This book was released on 1965 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reaction Dynamics written by I. Smith and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last 30 years our knowledge and understanding of molecular processes has followed the development of increasingly sophisticated tech niques for studying fast reactions. Although the results are reported in papers and reviews, it is sometimes difficult for those not themselves active in these fields to find their way through the mass of published material. We hope that each book in this series will present a clear account of the present state of knowledge in a particular field of physical chemistry to research workers in related fields, to research students, and for the preparation of undergraduate and post-graduate lectures. Each chapter describes the theoretical develop ment of one area of study and the appropriate experimental techniques; the results presented are chosen to illustrate the theory rather than to attempt a comprehensive review. The first volume published in 1972 was concerned with the reactions of small molecules and free radicals in the gas phase. The development of flash photolysis in the 1950s paved the way by making it possible to generate free radicals in sufficient concentration for a spectroscopic" snapshot" to reveal their molecular structure. Their role in kinetic systems could then be followed directly, rather than be inferred from mechanism. The shock tube enabled gas mixtures to be heated to any desired temperature in a time which was shorter than subsequent chemical reactions. Discharge-flow methods enabled the reactions of atoms and free radicals to be studied directly.
Download or read book Studies in Collisional Energy Transfer of Highly Rotationally and Vibrationally Excited Molecules written by Trevor C. Brown and published by . This book was released on 1988 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the studies made on several unimolecular reaction systems in order to obtain collisional energy transfer information on highly excited polyatomic molecules. Pressure-dependant very low-pressure pyrolysis (VLPP) and infrared multiphoton decomposition (IRMPD) experimental techniques are used.
Download or read book Vibrational Energy Transfer in Small Polyatomic Molecules written by N. J. G. Smith and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tracer based Planar Laser induced Fluorescence Diagnostics written by Brian Ho-yin Cheung and published by Stanford University. This book was released on 2011 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two advances to tracer-based planar laser-induced fluorescence (PLIF) diagnostics are presented in this work. The first improvement is the development of a 3-pentanone fluorescence quantum yield (FQY) database and model for a wide range of conditions in support of quantitative PLIF diagnostics. In addition, this work presents a sensitive, time-resolved tracer-based PLIF diagnostic, accomplished by using a continuous-wave (CW) laser with the high-FQY tracer toluene. Because of its ease of use and desirable photophysical properties, PLIF diagnostics using 3-pentanone as a tracer are common, particularly for internal combustion engine (ICE) diagnostics. Thus, there is a need for 3-pentanone FQY measurements and modeling over a wide range of temperatures, pressures, and excitation wavelengths. For insight into the collisionless process in the FQY model, measurements were made in 3-pentanone vapor at low-pressures across a range of temperatures using a flowing cell. Laser excitation with 248, 266, 277, 308 nm wavelengths were utilized, and Rayleigh scattering of the laser beam was used to calibrate the optical efficiency of the collection optics and detector. This low-pressure data allows calculation of the 3-pentanone fluorescence rate and non-radiative de-excitation rate in the fluorescence model. The vibrational relaxation cascade parameter for 3-pentanone collisions was also determined. Measurements of 3-pentanone FQY were also made over a range of temperatures and pressures relevant to diagnostic applications, and, in particular, combined high-temperature and high-pressure conditions applicable to internal combustion engines (ICE). These data were collected in a custom-built optical cell capable of simultaneous high-pressure and high-temperature conditions. The behavior of the FQY in nitrogen for temperatures up to 745 K and in air up to 570 K was examined for pressures from 1 to 25 bar. These data were used to further optimize the parameters in the FQY model representing collisional processes. The large quantity of data with 308 nm excitation allowed optimization of the nitrogen quenching rate, and data in air were used to optimize the oxygen quenching rate. These data were also used to optimize the vibrational relaxation parameters for nitrogen and oxygen. The model with the updated parameters is consistent with the data collected in the current work, as well as with fluorescence measurements made in optical ICEs up to 1100 K and 28 bar. Another area of tracer-based PLIF diagnostics development is time-resolved imaging. Because PLIF diagnostics are often performed using pulsed lasers, the time resolution of measurements is limited to the pulse rate of laser. Use of a high-powered visible laser with an off-the-shelf cavity frequency doubler is shown to produce a moderate-power CW beam in the ultraviolet wavelength regime. Application of this CW source to excite toluene, a high-FQY tracer, yields a sensitive, time-resolved tracer-based PLIF diagnostic. Fluctuation detection limits for tracer mole fraction were investigated by applying the diagnostic to an atmospheric temperature and pressure nitrogen jet seeded with 4% toluene, and detection limits of better than 1% of the maximum toluene mole fraction were achieved for detection of fluorescence signal at a point, along a line, and over a plane. The diagnostic was also demonstrated on a turbulent jet for line and planar detection and demonstrated the potential for toluene time-resolved PLIF diagnostics with CW lasers.
