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51.
D. R. S. Somayajulu Narendra Patel Mukesh Chawda Mitesh Sarkar K. C. Sebastian 《Hyperfine Interactions》2005,160(1-4):241-246
Hyperfine interaction techniques like Mossbauer spectroscopy are very sensitive tools to study the local probe interactions
in dilute magnetic semiconductors. We report here a Mossbauer study on the concentration dependence in Fe0.008Ge1 − x
Te
x
for x = 0, 0.008, 0.016, 0.03 and 0.05. At room temperature magnetic interactions were observed for all concentrations of Te and
the population of magnetic site was found to increase gradually with the Te concentration. A constant magnetic hyperfine field
of 136 KOe was found. A quadrupole doublet due to the FeTe2 compound phase was also seen. 相似文献
52.
In his study of combined finite extension and torsion of a nonlinear, incompressible, isotropic elastic circular cylinder, Rivlin [1] established a relation for the torsional stiffness which depends only on the axial force, the axial extension ratio and the radius of the undeformed cylinder, in the case of small twist. The relationship did not depend on the structure of the stored energy function and is hence a universal relation. In this paper, we extend Rivlin's result to the case of combined extension and torsion of a cylindrical mixture of a nonlinear elastic solid and fluid. 相似文献
53.
A thermodynamic analysis of sorption and transport in elastic solids is presented. The penetrant's chemical potential in the solid is calculated from the free energy changes that accompany deformation of the solid to accommodate the penetrant and mixing of the deformed solid and penetrant. Sorption isotherms are obtained by equating this chemical potential to that of that of the gas phase. The penetrant diffusivity is determined from a statistical mechanical analysis described in the literature. Both pure and mixed gas solubility, diffusivity and permeability are predicted. Mixed gas behavior is predicted using material parameters obtained from pure gas data only. The results suggest certain relationships between the dual mode model parameters that are found experimentally. Comparison with several experimental gas–polymer systems indicate the elastic solid analysis can reproduce pure gas data and predict mixed gas data well with physically realistic material parameters. The results provide a basis for investigating the relationships between the mechanical, volumetric, gravimetric and thermodynamic processes that give rise to transport. 相似文献
54.
In many scientific disciplines, measurements are taken from films that have been exposed to energetic sources. Examples include radiographs where the source is an X-ray tube, autoradiography where the source is a radioactive isotope and electrophoresis gels where the source is an enhanced chemiluminescence reaction. In these situations it is of interest to quantify the darkening of the film and compute the strength of the source which in the cases of autoradiography and electrophoresis can be used to compute unknown concentrations of biochemicals. We developed a simple mathematical model of the darkening of films in radiography, autoradiography and electrophoresis bands disclosed by enhanced chemiluminescence, and present formulae to calculate the strength of the source from measurement of film blackening by image analysis. A simple model is used in two examples to predict blackening of film exposed to electromagnetic radiation. This blackening is measured by image analysis. Results show reasonable agreement between predictions of the model and blackening of film for the examples chosen. This model is proposed as an aid to quantification of electrophoresis gels. 相似文献
55.
56.
Bhagyashri B. Kamble Tawade Anita K. Kamble Pravin Padavi Mukesh N. Sharma Kiran Kumar K. Ajalkar Balu D. Tayade Shivaji N. 《Russian Journal of Electrochemistry》2020,56(9):766-774
Russian Journal of Electrochemistry - A micro-bricks shaped tungsten oxide (WO3) was prepared by hydrothermal method. The prepared material was characterized by field emission scanning electron... 相似文献
57.
58.
Sandeep Goyal Anang Pal Mangilal Chouhan Mukesh Gangar Sharad Sarak Vipin A. Nair 《Tetrahedron letters》2017,58(4):346-348
An efficient strategy for a one-pot, single step synthesis of β-lactams employing an imidazolidinone based chiral auxiliary with various aldimines via asymmetric Mannich-type reaction has been described. 相似文献
59.
60.
Levulinic acid (LA) is an industrially important product that can be catalytically valorized into important value-added chemicals. In this study, hydrothermal conversion of glucose into levulinic acid was attempted using Brønsted acidic ionic liquid catalyst synthesized using 2-phenyl-2-imidazoline, and 2-phenyl-2-imidazoline-based ionic liquid catalyst used in this study was synthesized in the laboratory using different anions (NO3, H2PO4, and Cl) and characterized using 1H NMR, TGA, and FT-IR spectroscopic techniques. The activity trend of the Brønsted acidic ionic liquid catalysts synthesized in the laboratory was found in the following order: [C4SO3HPhim][Cl] > [C4SO3HPhim][NO3] > [C4SO3HPhim][H2PO4]. A maximum 63% yield of the levulinic acid was obtained with 98% glucose conversion at 180 °C and 3 h reaction time using [C4SO3HPhim][Cl] ionic liquid catalyst. The effect of different reaction conditions such as reaction time, temperature, ionic liquid catalyst structures, catalyst amount, and solvents on the LA yield were investigated. Reusability of [C4SO3HPhim][Cl] catalyst up to four cycles was observed. This study demonstrates the potential of the 2-phenyl-2-imidazoline-based ionic liquid for the conversion of glucose into the important platform chemical levulinic acid. 相似文献