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101.
Unsaturated Polyester resins were prepared by the reaction of cinnamylsuccinic acid with saturated diols, namely, ethylene, diethylene, propylene, dipropylene, tetramethylene, and hexamethylene glycols, and the unsaturated diols, namely, 1,4-butene- and 1,4-butynediols. All the polyester resins obtained have been characterized and were found to cure with styrene, with relatively low conversions. The properties of the cured polyesters in the form of films were determined. IR and 1H-NMR spectroscopy were used for both qualitative and quantitative analyses of the polyesters and their hydrolyzate products, after curing with styrene. 相似文献
102.
G. BEN ABDERRAZIK F. MILLOT G. MOULIN A. M. HUNTZ 《Journal of the American Ceramic Society》1985,68(6):302-306
To determine the transport properties of oxide scales growing on an alloy, a laboratory apparatus was developed which allows plotting of characteristic V = f (i) curves and oxidation with an applied electric field. The apparatus and formalism used are described; it appears that such experimental procedures allow determination of the mean ionic transport number, ti; the conductivity values σ, σi , and σ,e ; and the effective charge, Z*, of the moving species in the oxide scale (A12 O3 in the present case). 相似文献
103.
G. F. Miralamov 《Petroleum Chemistry》2006,46(6):447-449
A mixture of vanadyl porphyrin complexes was obtained from a metal-porphyrin concentrate (MPC) isolated from crude petroleum by selective extraction. The petroleum MPC was subjected to demetallization and the subsequent introduction of the vanadyl cation into the porphyrin ring. It was shown that the mixture of vanadyl-porphyrin complexes obtained from MPC catalyzes the cyclohexene epoxidation reaction. On the basis of experimental data, it was assumed that the mechanism of olefin oxygenation in the presence of vanadyl porphyrin complexes is similar to the mechanism of the Prilezhaev epoxidation reaction of unsaturated compounds. 相似文献
104.
Sarto M.S. Voti R.L. Sarto F. Larciprete M.C. 《Electromagnetic Compatibility, IEEE Transactions on》2005,47(3):602-611
New nanolayered coatings are designed and deposited on flexible plastic substrate having the thickness of 100 /spl mu/m, in order to realize lightweight ultrathin transparent shielding foils. The structure of the coating is optimized considering three figures of merit: the average transmittance in the visible range for normal incidence, the normalized average transmittance for oblique incidence at 550 nm, and the transmittance quality factor. The nanotechnology exploited for the deposition of the transparent metals is the dual ion beam sputtering. Tests of durability, optical transmission, and shielding effectiveness demonstrate that the film has a high adhesion under mechanical solicitation, high resistance against aging, peak transmittance in the visible range higher than 70%, omnidirectional properties in the range 0/spl deg/-60/spl deg/, and shielding effectiveness of 40 dB up to 6 GHz. 相似文献
105.
106.
P. Papet N. Le Bars J. F. Baumard A. Lecomte A. Dauger 《Journal of Materials Science》1989,24(11):3850-3854
Transparent yttria-stabilized zirconia monolithic gels were synthesized under controlled conditions for hydrolysis and chemical polymerization. The influence of acetylacetone on the previous chemical reactions was explored, and a plausible explanation was proposed concerning the outstanding role of this additive during the gelation process. Small-angle X-ray scattering was used to estimate the size of the polymeric species and to investigate the influence of acetylacetone on the structure of the gels prepared. 相似文献
107.
108.
Kitakami O. Ogawa Y. Fujiwara H. Kugiya F. Suzuki M. 《IEEE transactions on magnetics》1989,25(3):2607-2611
A Co-Cr film deposited directly on a substrate has an initial growth layer with low coercivity. However, the existence of a Ti underlayer prevents the formation of such a layer. As a result, Co-Cr film deposited on a Ti underlayer has high perpendicular anisotropy and coercivity even in cases of extremely thin film thickness (200 Å). As for the read-write characteristics of Co-Cr thin-film media, the existence of such an initial growth layer greatly improves the reproduced output level. The cause for this is considered to be that the free charges which appear on the back surface of the perpendicular recording layer are reduced and the demagnetization field acting on the recorded magnetization subsequently decreases due to the existence of the initial growth layer 相似文献
109.
Pilot simplex experiments for improving the tablet strength of three aspirin tablet formulations based on precompression and compression forces were presented. As each simplex moved towards the direction of the optimum, the friability was being minimized and the crushing strength was concomittantly being maximized. Because it followed a systematic direction, simplex process would locate a local optimum rapidly. The appropriate levels of precompression and compression forces that produced tablets with the desired strength were attained in five trials. By contrast, random search for this force combination required at least ten trials. Simplex technique is a cost and time effective means for determining the precompression and compression forces that will reduce the friability or increase the hardness of a tablet formulation. Results appeared to also indicate that crushing strength might be a more reliable measure of tablet strength than friability. 相似文献
110.
This paper derives the governing equations for the thermomechanical behaviour of composites. When the basic equations for the thermoelastic behaviour of solids were first derived in the nineteenth century several approximations were made. The effect of these assumptions are discussed and illustrated by the results of a simple laboratory test. The implications of this work on the analysis of impact damaged laminates are then discussed. 相似文献