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  • 1
    Electronic Resource
    Electronic Resource
    The Cs(7P)+H2→CsH+H reaction. I. Angular scattering measurements by Doppler analysis (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 434-444 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The Cs(7P)+H2→CsH (X 1Σ+) (v‘=0,J‘)+H reaction has been studied in a crossed-beam experiment, with electronic excitation of Cs atoms and laser-induced fluorescence detection of CsH products. The Doppler technique has been applied to determine the center of mass angular scattering probability of CsH products, for all rotational levels between 1 and 14 (in v‘=0) and for various values of the collision energy between 0.03 and 0.13 eV. We have used two complementary arrangements of the analysis laser beam: With a "parallel'' arrangement (the laser beam is along the collision axis), the shape analysis of fluorescence profiles leads directly to the angular scattering probability but experimental constraints limit the range of measurements; with a "perpendicular'' arrangement (the laser beam is perpendicular to the collision plane), fluorescence profiles are symmetrical and "forward'' contributions cannot be separated from "backward'' ones. However, extensive shape analyses have been performed with this perpendicular arrangement, since the direction of scattering was determined earlier by recording several profiles with the parallel arrangement. For the title reaction, it is shown unambiguously that, in the center of mass, CsH products scatter preferentially at small angle, in the forward direction with respect to the Cs initial velocity. The angular scattering probability varies with the collision energy but is independent of the rotational level of the product molecule (thus of its recoil velocity). These results are compatible with the harpooning mechanism which was suggested for the reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.459543
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  • 2
    Electronic Resource
    Electronic Resource
    The Cs(7P)+H2→CsH+H reaction. II. Rotationally resolved total cross sections (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 95 (1991), S. 3347-3360 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The Cs(7P)+H2→CsH(X 1Σ+)(v‘=0,J‘)+H harpooning reaction has been studied in a crossed-beam experiment, with electronic excitation of Cs atoms and laser-induced fluorescence detection of CsH products performed in a coherent saturation regime. Measurements of reactive cross sections have been achieved as a function of two parameters: The collision energy Ec (0.015≤Ec≤0.15 eV) and the rotational quantum number J‘ of CsH products (0≤J‘≤16, in v‘=0). For Ec=0.09 eV, the total reactive cross sections corresponding to the two 7P fine structure levels of Cs are σ(Cs(7P1/2)+H2)=4.2×10−16 cm2 and σ(Cs(7P3/2)+H2)=10−16 cm2. These cross sections are much smaller than expected for a harpooning reaction. This is interpreted from ab initio potential energy and quantal dynamics calculations which show that the efficiency of the photochemical reaction (Cs atoms in the 7P state) is limited by the quenching processes associated with the underlying potential energy surfaces connected with Cs atoms in the 6S, 6P, 5D, and 7S states. From the present measurements, one deduces that the rate of these quenching processes is larger than 90%. The rotational distributions of products in v‘=0 measured at two collision energies (Ec=0.045 and 0.09 eV) are close to "prior'' statistical distributions, with the same "surprisal.'' The energy dependence of rotationally resolved cross sections (J‘ fixed, Ec variable) confirms the reaction thresholds and shows that there is no potential barrier higher than 0.015 eV on the entrance valley and the exit valley of the reactive system; it is in agreement with the dependence predicted by hemiquantal dynamical calculations performed in the frame of a harpooning model. The uncertainty on the measurement of absolute cross sections is larger than 70%, but of the order of 20% for relative cross sections.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.460840
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  • 3
    Electronic Resource
    Electronic Resource
    Ab initio study of the potential energy surfaces of doublet valence and Rydberg states of FCO (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 3973-3980 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Multireference configuration interaction calculations (MRD-CI) were carried out in order to obtain the bending and stretching potential energy curves of several low-lying electronic states of the fluoroformyl radical FCO. The study of interactions between valence and Rydberg states as well as that of the dissociative behavior is included in the investigation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.467515
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  • 4
    Electronic Resource
    Electronic Resource
    Ab initio investigation of the vibrational structure of absorption and emission spectra of FCO (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 3981-3988 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Results of an ab initio study of the vibrational structure of several electronic spectral systems of FCO are presented. An interpretation of hitherto recorded spectra, as well as a prediction of features of yet unobserved electronic transitions is given. The absorption spectra observed in the uv spectral region are ascribed to the transitions involving the first excited states of 2A' and 2A‘ character. The emission spectrum obtained by Toby and Toby [J. Phys. Chem. 85, 4071 (1981)] is assigned to the transition X 2A'←2 2A‘. Reassignment of some observed vibrational bands is proposed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.467516
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  • 5
    Electronic Resource
    Electronic Resource
    η Production in proton-nucleus reactions (1991)
    Springer
    The European physical journal 340 (1991), S. 51-57 
    Details
    ISSN: 1434-601X
    Keywords: 25.40.−h
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The production ofη-mesons in proton-nucleus reactions is analysed with respect to primary nucleon-nucleon (NN→NNη) and secondary pion-nucleon (πN→ηN) production processes on the basis of Hartree-Fock groundstate momentum distributions and free on-shell production processes. The folding model adopted compares well for meson production with more involved simulations based on VUU transport equations. Similar to K+ production in proton-nucleus reactions theη-mesons are primarily produced by theπN →ηN channel. However,η-mesons are absorbed in nuclei via excitation of the N* (1535) resonance which leads to strong distortions of the primordial spectra. On the other hand, the experimental mass dependence of the differential cross sections might yield information about the in-medium properties of this resonance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01284480
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  • 6
    Electronic Resource
    Electronic Resource
    Hotspots of benthic production (1994)
    [s.l.] : Nature Publishing Group
    Nature 372 (1994), S. 47-47 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] SIR - Topographical features that accu-mulate organic debris, such as submarine canyons, are common along many coasts and can support hotspots of secondary production. The floor of the La Jolla sub-marine canyon (32° 52' N, 117° 15' W) is covered by a persistent mat of surfgrass and kelp ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/372047a0
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  • 7
    Electronic Resource
    Electronic Resource
    Osteogenesis imperfecta: A clinical study of the first ten years of life (1992)
    Springer
    Calcified tissue international 50 (1992), S. 36-41 
    Details
    ISSN: 1432-0827
    Keywords: O.I. childhood ; Clinical course ; Classification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary One hundred twenty-seven children with osteogenesis imperfecta (O.I.) were studied during the first 10 years of life. According to Sillence, 40 patients were assigned to type I, 39 to type III, and 48 to type IV O.I. Centiles for height, weight, and the annual number of fractures could be established for the different types of O.I. The development of the skeletal changes could be documented for the different forms of the disease. At birth, the skeletal changes were significantly more severe in type III than in type IV patients. During the first 10 years of life the number of fractures, extent of skeletal deformities, and growth retardation did not differ between types III and IV. Only fracture nonunion, dentinogenesis imperfecta, and congenital cardiac malformations were more frequent in type III than in type IV. Papillary calcifications of the kidney and kidney stones were diagnosed in 4 type III and 2 type IV patients. Hemihypertrophy of the body developed, in 2 type I patients. Although types III and IV patients suffered from severe short stature, serum insulin-like growth factor (IGF) I was in the normal range.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00297295
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  • 8
    Electronic Resource
    Electronic Resource
    Transient field measurements on32S(21 +) ions in Gd at the 1s electron Bohr velocity (1993)
    Springer
    The European physical journal 345 (1993), S. 1-5 
    Details
    ISSN: 1434-601X
    Keywords: 21.10.Ky ; 25.70.-z ; 27.30. + t
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract With the knowng-factor of the Coulomb excited first 2+-state in32S the transient magnetic field was determined for sulphur ions traversing Gd at a mean velocity of 16ν 0 (ν 0=c/137). The degree of polarization deduced for the dominating H-like ions, ¯p1s =0.10(3), agrees very well with that obtained at lower velocities. In addition, an upper limit of a transient electric field gradient was deduced from the particle-γ-angular correlation which is expected on theoretical grounds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01290332
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  • 9
    Electronic Resource
    Electronic Resource
    Isotope shift measurements in titanium I (1992)
    Springer
    The European physical journal 24 (1992), S. 161-164 
    Details
    ISSN: 1434-6079
    Keywords: 32.70.Jz ; 31.30.Gs ; 35.10.Bg
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The use of an effusive beam of titanium atoms crossed with a CW single-mode tunable dye laser has allowed the high-resolution, Doppler-free study of the isotope shifts between50Ti,48Ti and46Ti, for seven 3d 2 4s 2 a3 F J → 3d 2 4s 4p z 5 D J , visible transitions of Ti I. The measurements show without ambiguity the existence of a non-negligible field shift. Using the values of the nuclear radii of titanium (coming from muonic X-ray measurements), it is possible to determine the respective values of the field and mass shifts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01426701
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  • 10
    Electronic Resource
    Electronic Resource
    Isotope shift and hyperfine structure measurements in titanium I (1994)
    Springer
    The European physical journal 31 (1994), S. 145-148 
    Details
    ISSN: 1434-6079
    Keywords: 32.70.Jz ; 31.30.Gs ; 35.10.Bg
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract High accuracy measurements of hyperfine structure due to47Ti and49Ti in the 3d 2 4s 2 a 3 F 2−3d 2 4s4p z 5 D 1 absorption line at σ=18482.772 cm−1 have been performed by use of a Doppler-free experiment, where a beam of titanium atoms is crossed by a CW single mode tunable dye laser. They have allowed for the determination of isotope shifts between46Ti,47Ti,48Ti,49Ti and50Ti. By use of accurate values of mean square nuclear charge radii for the even isotopes, it has been possible to separate mass shifts from field shifts and to determine accurate values for the mean square nuclear charge radii of47Ti and49Ti. The field shift presents a marked odd-even staggering.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01437828
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