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991.
Electrical resistance measurements of Ag2Te thin films of different thicknesses, vacuum deposited on clean glass substrates held at room temperature in a vacuum of 5 × 10?5 Torr, have been carried out from about 300 to 450 K. A semiconducting-to-metallic-phase transition, which takes place during heating, is indicated by a sharp change in the slope of the resistance-vs-temperature curve. For films of different thicknesses the phase transition is found to occur at different temperatures. The size-dependent phase transition is explained by taking into account the varying surface and intergrain surface (interface) energy contributions to the total energy of the stable phase as a function of thickness and the difference in specific surface and integrain surface energies of the two phases. An order of magnitude of the difference in the function of specific surface and interfacial energies of the two phases is also made. 相似文献
992.
S.N. Das 《Physics letters. A》1984,102(8):338-339
In contrast to the three-wave hypothesis (TWH) presented earlier [1], it is argued in this letter that a massive particle in motion in a Lorentz frame will actually be associated with only two types of waves: (i) a transformed Compton wave and (ii) a superluminal de Broglie wave (B-wave). The subluminal wave (D-wave or D'-wave [2]) cannot be simultaneously correlated with the particle under consideration. 相似文献
993.
Here, we refer a new proposal of binary addition as well as subtraction in all-optical domain by exploitation of proper non-linear
material-based switching technique. In this communication, the authors extend this technique for both adder and subtractor
accommodating the spatial input encoding system. 相似文献
994.
The flow of various liquids and gases over single-walled carbon nanotube bundles induces an electrical signal (voltage/current)
in the sample along the direction of the flow. The electrical response generated by the flow of liquids is found to be logarithmic
in the flow speed over a wide range. In contrast, voltage generated by the flow of gas is quadratically dependent on the gas
flow velocity. It was found that the underlying physics for the generation of electrical signals by liquids and gases are
different. For the liquid, the Coulombic interaction between the ions in the liquid and the charge carriers in the nanotube
plays a key role while electrical signal generation due to gas flow is due to an interplay of Bernoulli’s principle and Seebeck
effect. Unlike the liquid case which is specific to the nanotubes, the gas flow effect can be seen for a variety of solids
ranging from single and multi-walled carbon nanotubes, graphite and doped semiconductors. 相似文献
995.
Ruchi Das 《Periodica Mathematica Hungarica》1995,31(2):123-130
Beginning with examples, the notion ofG-expansiveness over a metric spaceX on which a topological groupG acts is introduced. Some conditions are determined under which expansiveness onX impliesG-expansiveness. A characterization of aG-expansive homeomorphism is obtained which in turn gives a sufficient condition for the homeomorphic extension of aG-expansive homeomorphism to beG-expansive. At the end, some results are stated in the form of concluding remarks. 相似文献
996.
997.
The triglyceride profiles for corn, soybean, sunflower, grapestone, olive and olive husks oils were obtained by high temperature capillary gas chromatography on HT-FS capillary columns coated with OV-17-OH. The data were treated by methods of computerized pattern analysis, involving principal component analysis, discriminant analysis, and hierarchical clustering. A graphical representation of results as “star symbol plots” allows prompt visual recognition of the characteristic profiles and straightforward qualitative identification of unknowns as well as recognition of adulterations. 相似文献
998.
Tunable mid-infra-red radiation by singly resonant optical parametric oscillation based on KTA crystal pumped by multi-axial
Gaussian shape beam from Q-switched Nd:YAG laser has been demonstrated. Threshold energy of oscillation at different idler
wavelengths for different cavity length has been demonstrated. Single pass conversion efficiency of incident pump energy to
infra-red wavelength has also been measured. 相似文献
999.
Magnetic moments of decuplet baryons have been calculated in a relativistic independent quark model with a phenomenological
potential in equally mixed scalar-vector harmonic form. Such a model has been successful in describing wide ranging hadronic
phenomena in mesonic and baryonic sectors. Using the solutions of the constituent quark orbitals with the model parameters
taken from its earlier applications, the magnetic moments of decuplet baryons Δ++ and Ω− have been obtained which are in good agreement with the available experimental data. However, the agreement is found to be
much better when the magnetic moment ratios such as μδ++/μ
p and μΩ-/μΛ are considered. Model predictions for the magnetic moments of other decuplet baryons together with the charge radii have
also been calculated which may be verified in future experiments. 相似文献
1000.
A. Poddar S. Das D. Plachke H.D. Carstanjen 《Journal of magnetism and magnetic materials》2006,300(2):263-272
We report measurements of electrical resistivity (ρ), Hall coefficient (RH), magnetization (M) and specific heat (Cp(T)) of high-quality icosahedral Al70.4Pd20.8Mn8.8 phases with different thermal treatment. An improvement in the quasi-crystallinity upon the annealing treatment caused a drastic increase in ρ up to 7000 μΩ cm accompanied by a very small electronic specific heat coefficient γ. The low temperature ρ(T) data has been analyzed in terms of weak localization and electron–electron interaction effects. The Hall resistivity (ρH) is found to be strongly temperature-dependent and varies linearly with the magnetization (M) for the same field and temperature. Magnetization measurement reveals that more conductive samples are more magnetic and vice versa. Magnetic susceptibility (χ) data of all the annealed samples agrees with the Curie–Weiss-like behavior implying the existence of localized moments. The negative Curie–Weiss temperature (θ) indicates strong antiferromagnetic coupling between individual Mn atoms. The magnetic Mn concentration is found to be small, ranging from 1.73×10-4 for the less magnetic sample studied up to 3×10-3 for the more magnetic one. The small electronic specific heat coefficient obtained for all the samples suggests a significant reduction in the electronic density of states (DOS) at the Fermi level (EF) upon thermal annealing treatment. 相似文献