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  • 1
    Electronic Resource
    Electronic Resource
    Hydrogen/deuterium exchange reaction between chloroform and water-d2 in two-liquid-phase system (1989)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 93 (1989), S. 5139-5143 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100350a023
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  • 2
    Electronic Resource
    Electronic Resource
    Dissociation of cyclohexene and 1,4-cyclohexadiene in a molecular beam (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 4118-4127 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Molecular-beam photofragmentation translational spectroscopy of cyclohexene and 1,4-cyclohexadiene was carried out using 193 nm and IR multiphoton excitation. At 193 nm, both the retro-Diels–Alder reaction of cyclohexene and H2 elimination from both molecules were observed in the ground electronic state, indicating the occurrence of internal conversion from the initially excited electronic states. The retro-Diels–Alder reaction is shown to be concerted up to an internal energy higher than 148 kcal/mol. Hydrogen-atom elimination was also observed for both molecules following 193 nm excitation. The H atom is eliminated from an excited state of cyclohexene and is assigned to be from a carbon adjacent to the double bond, with a corresponding C–H bond energy of 87±3 kcal/mol. It is shown that the peak of the translational energy distribution for concerted dissociation in the ground state is determined mainly by the dynamics of the potential-energy release along the reaction coordinate, and is not sensitive to either the amount of internal energy or the form of excitation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.456841
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  • 3
    Electronic Resource
    Electronic Resource
    Preferential C–Cl bond rupture from 1-bromo-2-chloro-1,1,2-trifluoroethane following photoabsorption via n(Cl)→σ*(C–Cl) transition (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 1710-1713 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The photodissociation mechanism and dynamics of the title molecule have been studied at excitation wavelengths of 157 and 193 nm by using a photofragmentation translational spectroscopy. In the case of the excitation at 157 nm, the C–Cl and C–Br bond ruptures occur competitively with the branching ratio of 1.0:0.3, indicating the preferential C–Cl bond rupture over the weaker C–Br bond. The C–Br bond rupture occurred via two pathways; the dissociation on the excited repulsive potential energy surface and the dissociation of the vibrationally excited molecule in the ground electronic state following the internal conversion. In the case of 193 nm, only the C–Br bond rupture on the repulsive potential energy surface was observed. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.469741
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  • 4
    Electronic Resource
    Electronic Resource
    Infrared multiphoton dissociation of 2-chloro-1,1,1,2-tetrafluoroethane in a molecular beam (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 100 (1994), S. 6487-6491 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Mechanism and dynamics of the infrared multiphoton dissociation of 2-chloro-1, 1,1,2-tetrafluoroethane have been studied using a photofragmentation translational spectroscopy. The molecule dissociates competitively through three-centered elimination of HCl and C–Cl bond rupture. The HCl elimination reaction accounts for 74% of the total primary dissociation yields. The center-of-mass translational energy distribution for the HCl elimination indicates that an exit barrier of several kcal/mol exists along the reaction coordinate on the potential energy surface. The infrared multiphoton dissociation of CF3CF produced by the HCl elimination from CF3CHClF also occurs as a secondary process through its dissociation into two CF2 molecules. The average excitation energy of dissociating CF3CHClF has been determined to be about 20 kcal/mol above the C–Cl dissociation threshold of the molecule by comparing the observed center-of-mass translational energy distribution for the C–Cl bond rupture reaction with that calculated by Rice–Ramsperger–Kassel–Marcus (RRKM) theory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.467057
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  • 5
    Electronic Resource
    Electronic Resource
    Infrared multiphoton dissociation of CBrF2CHClF, CBrF2CHBrF, and CBrClFCBrF2 in a molecular beam (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 10602-10608 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Dynamics and mechanisms of infrared multiphoton dissociation of CBrF2CHClF, CBrF2CHBrF, and CBrClFCBrF2 have been studied using a photofragmentation translational spectroscopy. All molecules dissociated through C–Br bond rupture reactions. At high laser fluence, the halogenated ethyl radicals produced by the primary dissociation reactions dissociated through carbon–halogen bond ruptures. Center-of-mass product translational energy distributions for the C–Br and C–Cl bond ruptures of all halogenated ethanes and ethyl radicals studied are essentially consistent with those calculated by Rice–Ramsperger–Kassel–Marcus (RRKM) theory. This indicates that there exists essentially no exit channel barrier on the potential energy surface for the C–Br or C–Cl bond rupture of the halogenated ethanes and ethyl radicals. © 1994 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.468442
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  • 6
    Electronic Resource
    Electronic Resource
    The mechanism of the unimolecular dissociation of trichloroethylene CHCl=CCl2 in the ground electronic state (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 102 (1995), S. 7902-7909 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The unimolecular dissociation of trichloroethylene in its electronic ground state has been investigated using an infrared multiphoton dissociation combined with photofragmentation translational spectroscopy to measure product translational energies. The main reaction channel was found to be HCl elimination on the basis of observed product time-of-flight (TOF) spectra. A center-of-mass translational energy distribution for this channel provides direct evidence for competition between two channels, three- and four-centered HCl eliminations. Cl elimination was found to be a minor but significant channel from observed Cl+ and C2HCl+TOF spectra. The branching ratios were determined as 0.28, 0.55, and 0.17 for the three- and four-centered HCl eliminations and the Cl elimination, respectively. The three-centered channel exhibits a "statistical'' translational energy distribution which is typical for a reaction with no potential energy barrier in the reverse reaction, that is to say, no exit barrier reaction. In contrast, the four-centered channel exhibits a "nonstatistical'' translational energy distribution having a peak at around 2 kcal/mol in energy, indicating that a significant exit barrier exists in the channel. The fraction of potential energy converted to translational energy was estimated to be around 10%. Ab initio calculations at the QCISD(T)/6-311+G**//MP2(FC)/6-31G* level were employed to confirm the reaction mechanism. The agreement in the energetics is quite good. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.468989
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  • 7
    Electronic Resource
    Electronic Resource
    Photodissociation dynamics of CBrClF2 at 157.6 nm. I. Experimental study using photofragment translational spectroscopy (2001)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 114 (2001), S. 1617-1623 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Photofragment translational spectroscopy of CBrClF2 at 157.6 nm was carried out using a crossed laser-molecular beams technique. Detected species are Br, Cl, and CF2. From the analyses of time-of-flight (TOF) spectra for these three species, the molecules were found to dissociate competitively through CBrF2+Cl, CClF2+Br, and CF2+Br+Cl channels with the branching ratio of 1.0:1.6−0.22+0.13:0.87−0.18+0.13. All of the CClF2 and CBrF2 radicals were found to dissociate spontaneously to produce Cl or Br+CF2, respectively. The angular distributions of these secondary products were found to be anisotropic. These fast secondary reactions are discussed on the basis of the calculated dissociation rates and rotational frequencies. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1333007
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  • 8
    Electronic Resource
    Electronic Resource
    Photodissociation dynamics of CBrClF2 at 157.6 nm. II. A theoretical study using wave packet propagation (2001)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 114 (2001), S. 1624-1630 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Photodissociation dynamics from the repulsive nσC−X* (X=Cl,Br) states of CBrClF2 has been studied by propagating wave packets on the two diabatic potential energy surfaces obtained by an approximate diabatization of ab initio complete active space self-consistent field (CASSCF) potential energy surfaces. The diabatization was carried out so as to eliminate the transition-dipole moment between the two excited states. The results have confirmed the occurrence of simultaneous triple dissociation CBrClF2→Br+Cl+CF2 observed in the 157.6 nm photolysis of CBrClF2. The triple dissociation has been found to occur on both the upper and lower adiabatic surfaces with oscillation in the population in between. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1333016
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  • 9
    Electronic Resource
    Electronic Resource
    Strength analysis for three-dimensional fiber reinforced composites (1995)
    Springer
    Advanced performance materials 2 (1995), S. 161-176 
    Details
    ISSN: 1572-8765
    Keywords: finite-element method ; strength analysis ; three-dimensional composite material ; unit cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Three-dimensional fiber reinforced composite materials produced by impregnating resin into woven fabric have superior interlaminar and impact strength and are capable of being formed into complex shapes. Consequently it is expected in the future that they will be used for various structural members which have to date been difficult to make with conventional composite materials. With the growth in their fabrication technoloy, the development of a strength analysis method is being demanded. This paper describes a strength analysis method for three-dimensional composite materials on the basis of a micro-mechanical analysis of a unit cell. The unit cell is a small geometrical unit of fiber architecture. A feature of the present analysis method is to represent a unit cell as a rigid frame structure constructed of fiber-beam elements and matrix-beam and matrix-rod elements. Strength analyses are made for orthogonal weave and 5-axial weave three-dimensional carben/epoxy composite materials; the tensile, compressive, and shear moduli and strengths, and Poisson's ratio are calculated. The analytical results show fairly good agreement with experimental results; 11%, 21%, and 20% differences between them on the average for elastic moduli, strengths, and Poisson's ratios, respectively. It is also understood that the present idealized analysis model cannot accurately predict the characteristics of undulated fiber composites, especially in respect to the compressive strength.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00711269
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  • 10
    Electronic Resource
    Electronic Resource
    Basic Study of Progressive Crushing Mechanism (2000)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 177-180 (Apr. 2000), p. 321-326 
    Details
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/45/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.177-180.321.pdf
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