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1.
Nanosized Fe0.2Ni0.8 particles were prepared by reducing their salts with sodium borohydride (NaBH4) in cationic water-in-oil (w/o) microemulsions of water/cetyl-trimethyl-amonium bromide (CTAB) and n-butanol/isooctane at 25 °C. According to the TEM and X-ray diffraction analyses, the synthesized particles were around 4–12 nm in size. Due to their nanodimensions, the particles had a primitive cubic (pc) structure rather than the body-centered cubic (BCC) structure of the bulk material. An examination of the synthesis from the reverse micelle reveals that the morphology of the iron–nickel alloy nanoparticles depends mainly on the microemulsion's composition. The magnetization of the nanoparticles was much lower than that of the bulk material, reflecting the influence of the nanodimensions on the particles’ magnetizations. 相似文献
2.
We study the tangent space at a monomial point M in the Hilbert scheme that parameterizes all ideals with the same Hilbert function as M over an exterior algebra. 相似文献
3.
4.
John Cagnol Irena Lasiecka Catherine Lebiedzik Richard Marchand 《Comptes Rendus Mathematique》2006,342(9):711-716
This note is concerned with the non-linear shallow shell model introduced in 1966 by W.T. Koiter, and later studied by M. Bernadou and J.T. Oden. We show the uniqueness of the solution to the dynamical model and that this solution is continuous with respect to the initial data. To cite this article: J. Cagnol et al., C. R. Acad. Sci. Paris, Ser. I 342 (2006). 相似文献
5.
An inductively coupled plasma atomic emission spectrometry (ICP-AES) procedure has been developed and examined for the determination of boron content (0.01 up to about 2% B) in boron-alloyed steels such as POLDI ATA BOR (65% Fe, 19%Cr, 12% Ni, 1.5% Mn, 1% B), POLDI ATA BOR EXTRA (62% Fe, 18% Cr, 13% Ni, 2.5% Mo, 1.5% Mn, 1% B) and POLDI ATA BOR-R (75% Fe, 18% Cr, 3.5% Ti, 1.8% B). The steel sample is dissolved with a mixture of hydrochloric, nitric, sulfuric and phosphoric acids in a quartz vessel. Borides of alloyed metals, especially of iron and chromium, are quantitatively decomposed. The presence of phosphoric acid in a sample solution reduces the volatility of boric acid with water vapour.Presented in part at the 1989 European Winter Conference on Plasma Spectrochemistry, Reutte, Austria 相似文献
6.
Berezkin Victor G. Mardanov Robert G. Moiseew Aleksey A. Malinowska Irena Różyło Jan K. 《平面色谱法杂志一现代薄层色谱法》2002,15(5):377-379
JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
7.
Katarzyna Samson Anna Klisiska Irena Gressel Barbara Grzybowska 《Reaction Kinetics and Catalysis Letters》2002,77(2):309-315
VOx/TiO2 and MoOx/TiO2 catalysts with the addition of Re (Re/V or Mo = 0.5) were synthetized and tested in oxidative dehydrogenation of propane and in reduction by propane. XPS measurements showed depletion of the surface in Re. The Re additive does not affect the total conversion of propane, but increases the selectivity to propene. The effect is more pronounced for the MoOx/TiO2 catalyst. The increase in the selectivity to propene is accompanied with the increase in the reducibility of the catalysts. 相似文献
8.
Teplý F Stará IG Starý I Kollárovic A Saman D Vyskocil S Fiedler P 《The Journal of organic chemistry》2003,68(13):5193-5197
A nonphotochemical synthetic route to 3-hexahelicenol is reported. It involves a key [2+2+2] cycloisomerization of CH(3)O-substituted triyne that is readily available from 1-methoxy-3-methylbenzene and 1-bromo-2-(bromomethyl)naphthalene. Further functional group transformations led to 3-CO(2)CH(3), 3-NH(2), 3-PPh(2), and 3-SC(O)N(CH(3))(2) substituted hexahelicenes. 相似文献
9.
Stará IG Alexandrová Z Teplý F Sehnal P Starý I Saman D Budesínský M Cvacka J 《Organic letters》2005,7(13):2547-2550
[reaction: see text] A new approach to nonracemic [7]helicene-like molecules has been developed. Stereoselective Co(I)-mediated [2 + 2 + 2] cycloisomerization of aromatic triynes containing an asymmetric carbon atom produces [7]helicene-like scaffolds in diastereomeric ratios up to 100:0. This central-to-helical chirality transfer can be controlled by the absolute configuration at the asymmetric center and by the presence of carbon substituents. 相似文献
10.
Penna Thereza Christina Vessoni Marques Marcelo Machoshvili Irena A. Ishii Marina 《Applied biochemistry and biotechnology》2002,98(1-9):539-551
Large-volume parenteral solutions were submitted to heat treatments after being inoculated with Bacillus stearothermophilus ATCC 7953 (T
r
=121°C) and Bacillus subtilis ATCC 9372 (T
r
=104.5°C) spores. The average decimal reduction time for B. stearothermophilus ranged from a D
121°C value of 1.31 to 3.14 min, in glucophysiologic and Ringer’s solutions respectively. For B. subtilis, D
104.5°C value increased from 0.69 to 1.37 min, in Ringer’s (pH=5.91) and 50% glucose (pH 3.05) solutions respectively. The z value ranged from 7.95°C (20% mannitol solution) to 13.14°C (50% glucose solution), corresponding to an activation energy
(Ea) of 81.48 and 49.30 kcal/mol, respectively. 相似文献