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  • 1
    Electronic Resource
    Electronic Resource
    Ion/surface interactions as a tool for characterizing isomers: [C2H4O].cntdot.+ ions (1987)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 109 (1987), S. 7597-7602 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00259a002
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  • 2
    Electronic Resource
    Electronic Resource
    Efficient stator/rotor assembly for magic-angle spinning NMR (1987)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 58 (1987), S. 755-758 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A newly designed stator assembly for cylindrical spinners used in magic-angle spinning nuclear-magnetic-resonance experiments is described. Separate driving and bearing gas chambers allow variable and stable spinning speeds, and this design permits easy starting and stopping of the rotor. Isolation of the chambers is achieved with the application of pressure screws rather than O rings or glue lines to avoid leakage at high gas pressures. The overall dimensions are optimal to facilitate easy assembly. Some significant modifications have been made to an earlier spinner design. These improvements give better efficiency and concentricity of the spinner. Applications are illustrated with carbon-13 cross polarization/magic angle spinning (CP/MAS) spectra carried out at different rotor spinning rates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1139626
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  • 3
    Electronic Resource
    Electronic Resource
    The correlations among various elements in neutron activation analysis — The evaluation of R-matrix and κ-matrix (1987)
    Springer
    Journal of radioanalytical and nuclear chemistry 113 (1987), S. 169-175 
    Details
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The production rates (numbers of atoms per gram of the respective elements per second) of 40 radioactive nuclides of 34 elements by neutron capture reactions in a reactor were determined from about 130 photopeaks of the γ-ray spectra. The ratios of these production rates were called R-matrix elements. These production rates and the respective thermal neutron capture cross sections were used to calculate the respective apparent neutron fluxes at the position of irradiation and the κ-matrix elements which were the ratios of these apparent neutron fluxes. These matrix elements express clearly the correlations among various elements and thus may be used in the mono-standard or small-number-standards method in neutron activation analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02036058
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  • 4
    Electronic Resource
    Electronic Resource
    Stability and reactivities based on moment analysis (1989)
    Springer
    Theoretical chemistry accounts 75 (1989), S. 279-297 
    Details
    ISSN: 1432-2234
    Keywords: Hückel theory ; Moments ; Molecular topology ; Aromaticity ; Reactivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The truncated expansion of a function ¦x¦ is used to obtain the total Hückel π-electron energy partitioned into various sums, in terms of moments as well as molecular fragments. The additivity is in general satisfactory for acyclic and cyclic systems, which exhibit a regularity called the generalized Hückel rule which indicates whether a fragment plays the role of stabilization or of destabilization. A unified treatment based on the energy partitioning is proposed for rationalizing aromaticity, reactivities and bond lengths of conjugated hydrocarbons. The relationships between molecular properties and topology can be deduced from inspecting, enumerating or summing the relative contributions of various fragments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00533194
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  • 5
    Electronic Resource
    Electronic Resource
    Hydrogenation catalyzed by silica-supported polystannazane-palladium and platinum complexes (1988)
    Springer
    Polymer bulletin 19 (1988), S. 347-352 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary A new kind of inorganic polymer containing no organic groups, silica-supported polystannazane (abbr. as Sn-N), and its Pd and Pt complexes (abbr. as Sn-N-Pd and Sn-N-Pt respectively) were synthesized. When these two complexes were used to catalyze the hydrogenation of nitro- and carbonyl-compounds and the compounds containing C=C double bound, it was found that they have higher catalytic activity at room temperature and under atmospheric hydrogen pressure. The hydrogenation of carbonyl-compounds can be controlled in the alcohol stage, no further hydrogenation happened.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00263935
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  • 6
    Electronic Resource
    Electronic Resource
    Catalytic behavior of silica-supported polyalumazane-Co-Ru bimetallic complex for the hydroformylation of cyclohexene (1988)
    Springer
    Polymer bulletin 19 (1988), S. 353-357 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The cobalt and ruthenium bimetallic complex of an inorganic polymer, polyalumazane (abbr. as Al-N-Co-Ru), was prepared. The catalytic behavior of this complex for the hydroformylation of cyclohexene was studied. The conversion percents were more than 90% in a certain reaction temperature and pressure. Both of the conversion and product composition was also affected by the Ru/Co ratio in catalyst and the CO/H2 ratio in reactant gas. Aldehyde was firstly formed in the hydroformylation, and then it was further hydrogenated to form the corresponding alcohol. There was no any other by-product formed in the reaction. Compared with the corresponding homogeneous catalyst system, the Al-N-Co-Ru catalyst has higher catalytic activity and stability with lower Ru/Co ratio (1.86). After reused for several times, the catalyst did not lose its activity. The total turnover number was more than 2500 (based on the amount of cobalt used).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00263936
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  • 7
    Electronic Resource
    Electronic Resource
    Moments and characteristic polynomials of bipartite Hückel graphs (1989)
    Springer
    Journal of mathematical chemistry 3 (1989), S. 357-375 
    Details
    ISSN: 1572-8897
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mathematics
    Notes: Abstract Moments (u k ) and coefficients of characteristic polynomials (a k ) have been evaluated in terms of molecular fragments up tok = 12 for bipartite Hückel graphs. Based on combinatorial analysis, each coefficient can be derived as a combination of binomial factors mapping to the corresponding multi-component graphs. The general formula becomes lengthy as k increases, but can be considerably simplified for a homologous series. This has been illustrated by dealing with the cata-condensed benzenoid hydrocarbons as a corollary where a rather compact set ofa k has been deduced. On combining the present result with Coulson's formula, one gains insight into the relative stability of isomers in relationship to the energy contribution of fragments classified as stabilized and destabilized species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01169017
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  • 8
    Electronic Resource
    Electronic Resource
    Characterization of and energy deposition in [C2H4O2]+· ions using energy-resolved mass spectrometry (1986)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 21 (1986), S. 101-103 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Energy-resolved mass spectrometry (ERMS) has been used to distinguish [C2H4O2]+· ions generated from seven precursor molecules. The low collision energy ERMS data confirm conclusions reached from previous high-energy experiments; all seven ions have different structures or mixtures of structures. Structural distinctions are at least as easy to make using the two-dimensional ERMS data as through collisional activation at high energy. The average internal energy deposited in low-energy collisions (30 eV) is shown to be similar to the internal energy deposited at 8 keV in these systems.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210210302
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