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31.
Fe polycrystalline nanowires were electrodeposited in nanoporous anodized alumina membranes. Their magnetic properties were studied at 10 K. The behavior of the isothermal remanence Mr and the demagnetization remanence Md was determined. The corresponding ΔM plot revealed the character demagnetizing of the dominant interactions. A simple analysis suggests that curling is the reversal magnetization mode in these samples. The forms of the Mrev(Mirr)Hi curves were different from those encountered until now, and it seems that these forms are associated with the curling reversal mode. 相似文献
32.
Marina Cornejo Bashkim Ziberi Christoph Meinecke Dietmar Hirsch Jürgen W. Gerlach Thomas Höche Frank Frost Bernd Rauschenbach 《Applied Physics A: Materials Science & Processing》2011,102(3):593-599
This report focuses on the effect of simultaneous Fe incorporation in the self-organized pattern formation on Si(001) by low-energy
ion-beam sputtering. Experimental observations giving evidence for the correlation between different ion-beam parameters,
Fe concentration on the substrate, and the resulting topography are shown. It was observed that the incorporation of Fe affects
the evolution of the topography and it is a requisite for the formation of ripples at near-normal incidence. It is shown also
that Fe is not homogeneously distributed on the surface, but there is a higher concentration at the crests of the ripples
than at the valleys. For the experimental setup used for this study, the Fe flux that reaches the surface is determined mainly
by the acceleration voltage (U
acc), while the ion energy (E
ion) and ion-beam incidence angle (α) control the concentration of Fe in the steady state. The adjustment of these operational parameters of the ion source enables
the fine-tuning of surface patterns. 相似文献
33.
In this paper we investigate those subvarieties of the variety $\mathcal {SH}$ of semi-Heyting algebras which are term-equivalent to the variety $\mathcal L_{\mathcal H}$ of Gödel algebras (linear Heyting algebras). We prove that the only other subvarieties with this property are the variety $\mathcal L^{\rm Com}$ of commutative semi-Heyting algebras and the variety $\mathcal L^{\vee}$ generated by the chains in which a?<?b implies a → b?=?b. We also study the variety $\mathcal C$ generated within $\mathcal{SH}$ by $\mathcal L_{\mathcal H}$ , $\mathcal L_\vee$ and $\mathcal L_{\rm Com}$ . In particular we prove that $\mathcal C$ is locally finite and we obtain a construction of the finitely generated free algebra in $\mathcal C$ . 相似文献
34.
Salt effects on the reactions [Fe(CN)6]4? + S2O=8 and [Ru(NH3)5py]2+ + S2O have been studied in media of different dielectric constants constituted by mixtures of water with organic cosolvents. It is known that salt and solvent effects are coupled and, consequently, cannot be treated separately. This implies that salt (and solvent) effects need to be carefully analyzed before using them as a tool for mechanistic discrimination. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 582–588, 2009 相似文献
35.
A.C.F.M. Costa A.P.A. Diniz A.G.B. de Melo R.H.G.A. Kiminami D.R. Cornejo A.A. Costa L. Gama 《Journal of magnetism and magnetic materials》2008
Ni–Zn ferrites have been widely used in components for high-frequency range applications due to their high electrical resistivity, mechanical strength and chemical stability. Ni–Zn ferrite nanopowders doped with samarium with a nominal composition of Ni0.5Zn0.5Fe2−xSmxO4 (x=0.0, 0.05, and 0.1 mol) were obtained by combustion synthesis using nitrates and urea as fuel. The morphological aspects of Ni–Zn–Sm ferrite nanopowders were investigated by X-ray diffraction, nitrogen adsorption by BET, sedimentation, scanning electron microscopy and magnetic properties. The results indicated that the Ni–Zn–Sm ferrite nanopowders were composed of soft agglomerates of nanoparticles with a high surface area (55.8–64.8 m2/g), smaller particles (18–20 nm) and nanocrystallite size particles. The addition of samarium resulted in a reduction of all the magnetic parameters evaluated, namely saturation magnetization (24–40 emu/g), remanent magnetization (2.2–3.5 emu/g) and coercive force (99.3–83.3 Oe). 相似文献
36.
Rainer Richter Uwe Schrder Lothar Beyer Jorge Angulo‐Cornejo Maria Lino‐Pacheco 《无机化学与普通化学杂志》2001,627(8):1877-1881
Mononuclear Copper(II) Complexes of Dioxaalkylene and Alkylene Bridged Bis‐isoureas By reaction of N‐benzoylthiocarbamic‐O,S‐diethylester with primary diamines (oxa)alkylene bridged isoureas 1 have been prepared. They yield with CuII neutral chelates 2 with tetradentate ligand coordination. The structures of the ligand 1 a and of the related CuII complex 2 a have been determined by X‐ray crystal structure analysis. They show an enamine tautomer in the ligand and a slightly tetrahedrally distorted coordination with an (oxa)alkylene bridge between the trans arranged N ligator atoms in the complex. 相似文献
37.
Alfonso Cornejo 《Colloid and polymer science》1913,12(1):1-6
Ohne Zusammenfassung 相似文献
38.
39.
The polymerization of methyl methacrylate initiated by triethylborane-peroxides and by triethylborane-AIBN mixtures has been studied. From the dependence of rate of polymerization and molecular weight of the polymer on the triethylborane concentration. It is concluded that the initiation is complex. An initiation mechanism involving triethylborane-monomer and triethylborane-cocatalyst complexes is proposed. 相似文献
40.
Chiral Pybox-Ru catalysts can be microencapsulated into linear polystyrene as a method to recover and recycle the valuable catalyst. These catalysts allow 60-68% yields to be achieved with enantioselectivities in the range 75-85% ee in the benchmark cyclopropanation reaction between styrene and ethyl diazoacetate. The catalyst is soluble in the reaction solvent and is re-encapsulated at the end of the reaction. The great advantage of this methodology is that the chiral ligand does not need to be modified, but the recycling is highly solvent dependent—in contrast with the catalysts immobilized through covalent bonds. 相似文献