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21.
An isoelectric focusing method capable of resolving all groups of storage protein of the wheat seed, including the most basic low molecular weight glutenin (LMWG), was developed. Ultrathin polyacrylamide gels were used after drying and rehydration with 8 M urea, 50 mM DTE and 2.4% carrier ampholytes (pH 4-9). Densitometric scanning of the isoelectric focusing gels permitted a more accurate and specific quantitation of LMWG components among various cultivars than patterns based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The two main genetic types (i.e. 'gamma-42' and 'gamma-45') of durum wheats were separated on the basis of the proportion in LMWG in storage proteins, but no significant difference was found within these groups. Advantages of the system as regards reliability, high resolution, ability to abolish protein oxidation and preventing reaggregation of LMWG were also discussed. 相似文献
22.
Josette Olivier-Fourcade Costana Mihaela Ionica-Bousquet Pierre-Emmanuel Lippens Jean-Claude Jumas 《Hyperfine Interactions》2012,207(1-3):33-36
Due to their high storage capacity Sn-based materials are of considerable interest as negative electrode for Li-ion batteries. However the strong volume change occurring during the alloy formation strongly limits the electrochemical performances (cycle and time life). Analysis by M?ssbauer spectroscopy using model compounds (Sn, Sn-Li and transition metal-Sn alloys) shows that the volume expansion is related to the structural change from a Sn based network to a Li based network. Two types of materials are proposed here to overcome this problem: tin dispersion in an electrochemically inactive oxide matrix with buffer role to absorb volume changes or tin alloying with an inactive transition metal to minimize the volume expansion. The use of M?ssbauer spectroscopy (in situ operando mode) allows a dynamic approach which is essential to understand the fundamental causes of ageing on cycling and to define then the key issues to be solved for material’s application. 相似文献
23.
M. E. Carlotti E. Ugazio S. Sapino D. Vione B. Fubini S. Morel 《Journal of Dispersion Science and Technology》2013,34(7):994-1003
Titanium dioxide is a sunscreen pigment with photocatalytic activity. We studied the behavior of different TiO2 specimens used in cosmetic products on the UVB-induced peroxidation of linoleic acid as model substrate and of porcine skin, at different pH values. Lipoperoxidation of linoleic acid occurred to a lower extent with the coated compared to the uncoated TiO2, and it decreased at pH 7.0 compared to 4.0. The addition of organic additives such as propylene glycol and ethanol induced a significant reduction of the lipoperoxidation activity, particularly with the most reactive TiO2 specimens. Similar results were obtained with the porcine skin. 相似文献
24.
Jean-Michel Morel Filippo Santambrogio 《Archive for Rational Mechanics and Analysis》2010,195(2):499-531
A branched structure is observable in draining and irrigation systems, in electric power supply systems, and in natural objects
like blood vessels, the river basins or the trees. Recent approaches of these networks derive their branched structure from
an energy functional whose essential feature is to favor wide routes. Given a flow s in a river, a road, a tube or a wire, the transportation cost per unit length is supposed in these models to be proportional
to s
α with 0 < α < 1. The aim of this paper is to prove the regularity of paths (rivers, branches,...) when the irrigated measure
is the Lebesgue density on a smooth open set and the irrigating measure is a single source. In that case we prove that all
branches of optimal irrigation trees satisfy an elliptic equation and that their curvature is a bounded measure. In consequence
all branching points in the network have a tangent cone made of a finite number of segments, and all other points have a tangent.
An explicit counterexample disproves these regularity properties for non-Lebesgue irrigated measures. 相似文献
25.
Metal phosphorothioates are titrated in acetone, acetonitrile and dimethylformamide with potassium hydroxide, with potentiometric detection. They can be titrated in the presence of the corresponding phosphorothioic acids in the dimethylformamide. 相似文献
26.
Synthesis of 5-aryl[3,2-b]thieno-7-pyranones or thiopyranones and [3,2-b]thieno-9-chromenones from 3-methoxy or 3-thiomethoxy thiophenes is described, involving the use of pyridinium chlorhydrate as a cyclising and demethylating agent. 相似文献
27.
A method is proposed to identify gluon jets in the planar hadronic events recently found in e+e? annihilation. If a fast hadron is detected at a given angle θh ? 30° with respect to the axis opposite to the thrust axis, it is most probably a quark (or antiquark) fragment. An explicit formula then predicts the angle and energy of the unbiased accompanying gluon. 相似文献
28.
Intergranular and transgranular fracture surfaces obtained in a face centered cubic alloy are studied using 3D maps reconstructed by scanning electron microscopy stereo imaging. The roughness exponents measured in the intergranular and transgranular surfaces, respectively, zeta = 0.83 +/- 0.05 and zeta = 0.75 +/- 0.05, are in agreement with the universal roughness value of 3D fractures. However, the slightly smaller value related to the transgranular surface could be a consequence of crystallographic transgranular zones disseminated on the surface whose roughness exponent zeta = 0.65 +/- 0.07 is close to the one usually measured on 2D fractures. 相似文献
29.
Robert Morel Ariel BrenacCéline Portemont Thierry DeutschLucien Notin 《Journal of magnetism and magnetic materials》2007
Magnetic anisotropy has been measured in multiply twinned, icosahedral cobalt clusters. It is found that the low-temperature magnetization of deposited cluster layers is well defined with the Stoner–Wohlfarth model by averaging over clusters with a range of anisotropy energy. Anisotropy energy calculation based on Néel's pair model shows that the icosahedral structure and the layer-by-layer growth of the clusters induce oscillations of the magnetic anisotropy as a function of the filling of the outer surface of the particle. The magnetization measurement at room temperature indicates a weakly correlated cluster glass, as deduced from the approach to saturation that is well described with 2D random anisotropy model. 相似文献
30.
Jean-Claude Tabet Chantal Prevost Anne Bouillot Josette Bastard Due Do Khae Manh Yves Tondeur 《Helvetica chimica acta》1986,69(4):806-815
A stereospecific and regioselective SN2 mechanism (Walden inversion) is observed during studies involving modified terpenoid epimeric diols in a high-pressure ion source using ammonia as a reagent gas. 相似文献