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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 5217-5221 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ni–P–B ultrafine amorphous alloy particles have been prepared by chemical reaction of nickel chloride, sodium hypophosphite, and potassium borohydride in aqueous solution. Two samples prepared at different initial pH values (pH=5 and 9) have been characterized by different experimental methods. X-ray and electron diffraction indicated that both samples were amorphous in nature, and transmission electron microscopy gave average diameters of 50 and 30 nm for particles prepared at pH=5 and 9, respectively. X-ray photoelectron spectroscopy revealed that nickel and phosphorus existed exclusively in their elemental states, while boron existed mainly in its elemental state but with some trace of its oxide on the surface. The crystallization process of the amorphous samples was investigated by differential scanning calorimetry and by x-ray diffraction after annealing the samples at various temperatures. The results are correlated with the microstructure of the as-prepared samples. It is found that when the initial pH of the reaction mixture is adjusted to 9, the pH value can be maintained automatically throughout the reaction and the sample thus formed has a fairly homogeneous microstructure.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 3849-3851 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A novel small-period wiggler constructed of edgy-wound bifilar-helical conducting sheets with ferromagnetic cores, intended for free-electron lasers (FELs), is presented, and the performance characteristics of the wiggler prototype with 10-mm period are measured. A field as high as 500–1000 G has been obtained. It is feasible to make a Raman FELs with this type of wiggler operating in the wavelength range of millimeters and submillimeters with a low electron energy (〈500 keV) beam.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 59 (1991), S. 3545-3546 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ni-P ultrafine amorphous alloy particles have been prepared by reacting nickel chloride and sodium hypophosphite in an aqueous solution. X-ray diffraction revealed the amorphous structure of the particles and transmission electron microscopy showed that the particles are spherical, with an average diameter of about 150 nm. X-ray photoelectron spectroscopy confirmed that all nickel and phosphorus atoms are in the elementary state on the surface of the particles, which implied the alloying state of the particles. The dynamic process of the reaction has been studied. It is found that the reaction ended within 65 min at a pH value of 10 and 351 K when the sodium hypophosphite was exhausted, and the unreacted solid residue Ni(OH)2 should be washed out with ammonia solution to obtain "pure'' Ni-P ultrafine amorphous alloy particles.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Berkeley, Calif. : Berkeley Electronic Press (now: De Gruyter)
    International journal of chemical reactor engineering 3.2005, 1, A9 
    ISSN: 1542-6580
    Source: Berkeley Electronic Press Academic Journals
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The dynamic behavior of a multistage agitated contactor has been numerically studied for its potential use for catalytic hydrogenation of nitrile butadiene rubber. A model consisting of stirred tanks in series with back flow is applied to describe the flow behavior in the presence of hydrogenation within a multistage agitated contactor of six stages. The coupled behavior between kinetics and mass transfer is analyzed by manipulating parameters involved in the model. The model predicted that the performance of the reactor is completely governed by the ability of the catalyst in activating hydrogen, the loading level of C=C double bonds, the relative capacity of the reaction to mass transfer, and the backmixing. Mass transfer and backmixing are important factors for the hydrogenation process and enhancing mass transfer and minimizing backmixing helps in increasing hydrogenation conversion. The effects of backmixing and the number of stages for the hydrogenation are discussed, and optimal operation conditions are suggested.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Macromolecules 28 (1995), S. 6055-6066 
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Catalysis letters 12 (1992), S. 51-62 
    ISSN: 1572-879X
    Keywords: Incorporation model ; r-alumina ; hydroxyl group density ; dispersion capacity ; MoO3 ; NiO ; CuO
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract An incorporation model has been proposed and used to discuss the interaction between various metal oxides and γ-alumina. The dispersion capacities of various metal oxides are predicted and the surface hydroxyl group density on γ-alumina estimated, based on the assumption that the (110) plane is preferentially exposed on the surface of γ-alumina. These results are in good agreement with the available experimental data.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The crystallization process of a−Fe35Ni15B26 ultrafine alloy particles prepared by chemical reduction with borohydride was investigated mainly by Mössbauer spectroscopy. The experimental results exhibit some new characteristics which were attributed to the microstructure of the sample.
    Type of Medium: Electronic Resource
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