102 research outputs found
Magnetic Field Dependence Of The Curie-weiss Paramagnetism In Crv Alloys
The determination of the magnetic properties of antiferromagnetic Cr alloys requires careful consideration of the influence of the applied magnetic field. In this work we show that alloys of Cr-x at. % V present a Curie-Weiss paramagnetism above the Néel temperature, which is suppressed by a characteristic field HL. Samples with x=0.1, 0.2, and 0.4 were investigated through measurements of the magnetic susceptibility as a function of temperature, for different values of the magnetic field. A magnetic phase diagram showing the characteristic line HL vs x at. % V is proposed. © 1997 American Institute of Physics.818 PART 2A42094211Suzuki, T., Takaki, H., (1964) J. Phys. Soc. Jpn., 19, p. 1241Suzuki, T., (1966) J. Phys. Soc. Jpn., 21, p. 442Aidun, R., Arajs, S., Moyer, C.A., (1985) Phys. Status Solidi B, 128, p. 133Hill, P., Ali, N., De Oliviera, A.J.A., Ortiz, W.A., De Camargo, P.C., Fawcett, E., (1994) J. Phys. Condens. Matter., 6, p. 1761De Oliveira, A.J.A., Otriz, W.A., De Camargo, P.C., Galkin, V.Yu., (1996) J. Magn. Magn. Mater., 152, p. 86De Oliveira, A.J.A., De Lima, O.F., De Camargo, P.C., Ortiz, W.A., Fawcett, E., (1996) J. Phys. Condens. Matter., 8, pp. L403Benediktsson, G., Hedman, L., Aström, H.U., Rao, K.V., (1982) J. Phys. F, 12, p. 1439Booth, J.G., (1964) Phys. Status Solidi, 7 K, p. 157Bender, D., Müller, J., (1970) Phys. Kondens. Mater., 10, p. 342Buzdin, A.I., Men'shov, V.N., Tugushev, V.V., (1986) Zh. Eksp. Teor. Fiz., 91, p. 2204(1986) Sov. Phys. JETP, 64. , Engl. TranslTugushev, V.V., (1992) Modulated and Localized Structures of the Spin-Density Wave in Itinerant Antiferromagnets in Electronic Phase Transitions, p. 237. , edited by W. Hanke and Yu. Koapev Elsevier, AmsterdamDe Oliveira, A.J.A., De Lima, O.F., Ortiz, W.A., De Camargo, P.C., (1995) Solid State Commun., 96, p. 383De Oliveira, A.J.A., (1996), PhD. thesis, Universidade Federal de São Carlo
Efeito de fontes e de aditivos na absorção de 35S via foliar pelo feijoeiro
A greenhouse experiment was carried out with the aim of evaluating the effect of sulphur sources, in the presence or absence of additives (urea and glucose), on the sulphur uptake by bean leaves. The treatments: solutions of sulphuric acid, ammonium, potassium, magnesium, manganese and zinc sulphates labelled with 35S, containing or not the additives, were applied to the first trifoliate of the plants to assess the sulphur uptake and translocation. The results enable to conclude that 33% of the added sulphur was absorved, and 27% out of this total was translocated. The additives did not have any influence on uptake and translocation. The sulphuric acid and ammonium sulphate solutions were the best sulphur suppliers for the bean plant.Foi conduzido em casa de vegetação um experimento com o objetivo de avaliar o efeito de fontes de enxofre, na presença ou não de aditivos (uréia e glicose), sobre a absorção do demento pelas folhas de feijoeiro. Os tratamentos: soluções de ácido sulfúrico e de sulfates de amonio, potássio, magnésio, manganês e zinco marcadas com 35S, contendo ou não os aditivos, foram aplicados ao primeiro trifólio das plantas para avaliar a absorção e translocação de enxofre. Os resultados permitiram concluir que 33% do S adicionado foi absorvido, e desse total 27% foi translocado, não havendo influência dos aditivos sobre esses processos. O ácido sulfúrico e o sulfato de amonio destacaram-se como os melhores fornecedores de enxofre, via foliar, para o feijoeiro
A concentração de fósforo na tolerância de cultivares de trigo à toxicidade de alumínio em soluções nutritivas
Spanning forests and the q-state Potts model in the limit q \to 0
We study the q-state Potts model with nearest-neighbor coupling v=e^{\beta
J}-1 in the limit q,v \to 0 with the ratio w = v/q held fixed. Combinatorially,
this limit gives rise to the generating polynomial of spanning forests;
physically, it provides information about the Potts-model phase diagram in the
neighborhood of (q,v) = (0,0). We have studied this model on the square and
triangular lattices, using a transfer-matrix approach at both real and complex
values of w. For both lattices, we have computed the symbolic transfer matrices
for cylindrical strips of widths 2 \le L \le 10, as well as the limiting curves
of partition-function zeros in the complex w-plane. For real w, we find two
distinct phases separated by a transition point w=w_0, where w_0 = -1/4 (resp.
w_0 = -0.1753 \pm 0.0002) for the square (resp. triangular) lattice. For w >
w_0 we find a non-critical disordered phase, while for w < w_0 our results are
compatible with a massless Berker-Kadanoff phase with conformal charge c = -2
and leading thermal scaling dimension x_{T,1} = 2 (marginal operator). At w =
w_0 we find a "first-order critical point": the first derivative of the free
energy is discontinuous at w_0, while the correlation length diverges as w
\downarrow w_0 (and is infinite at w = w_0). The critical behavior at w = w_0
seems to be the same for both lattices and it differs from that of the
Berker-Kadanoff phase: our results suggest that the conformal charge is c = -1,
the leading thermal scaling dimension is x_{T,1} = 0, and the critical
exponents are \nu = 1/d = 1/2 and \alpha = 1.Comment: 131 pages (LaTeX2e). Includes tex file, three sty files, and 65
Postscript figures. Also included are Mathematica files forests_sq_2-9P.m and
forests_tri_2-9P.m. Final journal versio
IPR 126 white oat forage potential under free growth, cutting and grazing at two management heights
Desempenho e características de carcaça de novilhos de origem leiteira, alimentados com diferentes níveis de concentrado e de cama de frango
Bromatological and mycotoxin analysis on soybean meal before and after the industrial process of micronization
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