Results from Super-Kamiokande-I’s entire 1496 live days of solar neutrino data are presented, including the absolute flux,
energy spectrum, zenith angle (day/night) and seasonal variation. The possibility of MSW and vacuum oscillations is discussed
in light of these results. Results from the first 1289 days of Super-K-I’s atmospheric neutrino analysis are also presented,
including the evidence for νμ →ντ oscillations, against νμ → νsterile oscillations, and the current limits on proton decay. Finally, results based on 56 × 1019 protons on target are given for the K2K long-baseline neutrino oscillation experiment. 相似文献
We present an interpretation of the recent neutron data on the commensurate and incommensurate spin fluctuations found in YBa2Cu3O6+y based on a special configuration of the electronic dispersion and intervention from the dx2−y2-wave superconducting phase. The observed switch-over between the commensurate and incommensurate fluctuation spectra at the change of frequency or temperature is naturally accounted within this scenario. 相似文献
We have investigated numerically the plasmonic effect on a two-dimensional periodic array of metallic nanostructures. The unit cell of the array has an Ag nanosphere and nanorod pair formed in a single structure. Three-dimensional finite element method is used for the study on the sensing performance within the optical spectra. The study takes into account the influences of the structural and material parameters, the rotational angle of the metal nanostructure, the number of metal nanostructure per unit cell, and the localized surface plasmon resonances. The proposed nanostructures function as a refractive index sensor with a sensitivity of 400 nm/RIU (RIU is the refractive index unit), showing the characteristics of low transmittance (T?=?3.90%), high absorptance (A?=?94.5%), and near-zero reflectance (R?=?0.15%), could be achieved by a triangular arrangement of nanostructures within a unit cell. We also show how the tailoring of the structural parameters relates to the specific sensing schematics of the sensor.
Graphical abstractx-y sectional plane of electric field intensity, electric force lines (pink lines), energy flows (green arrows) and surface charge density of type 2, corresponding to the surrounding testing medium of (a) n=1.00 and (b) n=1.33 around the PMNSs.
Rare earth element substituted bismuth ferrites (BiFeO3) are of enormous importance as magnetoelectric materials. The polycrystalline samples of BixLa1−xFeO3 (x=0, 0.2, 0.4, 0.6, 0.8) were prepared by solid-state reaction using standard ceramic method. The single-phase formation of
these compounds was confirmed by X-ray diffraction (XRD) studies. The samples with x=0, 0.2, 0.4, 0.6 are found to be orthorhombic while the sample with x=0.8 is triclinic. The dielectric constant (ε′) and dissipation factor (tan δ) were measured in the frequency range 100 Hz
to 1 MHz at room temperature and as a function of temperature at certain fixed frequencies (1 kHz, 10 kHz, 100 kHz, 1 MHz).
All the samples showed dielectric dispersion. The dielectric constant with temperature shows a broad peak; the peak temperature
shifts with frequency which reflects the relaxor-type behavior. The peak above 600 K in the measured temperature range corresponds
to antiferromagnetic ordering temperature (Néel temperature). The broadness of the peak changes with composition. The ac conductivity
as well as ε′ are found to be maximum for the sample x=0.2 at room temperature. 相似文献
CoFe2O4-BaTiO3 composites were prepared using conventional ceramic double sintering process with various compositions. Presence of two phases
in the composites was confirmed using X-ray diffraction. The dc resistivity and thermoemf as a function of temperature in
the temperature range 300 K to 600 K were measured. Variation of dielectric constant (ɛ′) with frequency in the range 100 Hz to 1 MHz and also with temperature at a fixed frequency of 1 kHz was studied. The ac
conductivity was derived from dielectric constant (ɛ′) and loss tangent (tan δ). The nature of conduction is discussed on the basis of small polaron hopping model. The static value of magnetoelectric
conversion factor has been studied as a function of magnetic field. 相似文献
The absorbance spectra of thin-film solar cells (TFSCs) can be enhanced by constructing the tunable periodic Ag-shell nano-bead (PASNB) arrays in the active material. In this paper, we investigated a plasmonic thin-film solar cell (TFSC) which composed of the arrays of PASNB deposited onto a crystalline silicon layer. By performing three-dimensional finite element method, we demonstrate that near field coupling among the PASNB arrays results in SPR modes with enhanced absorbance and field intensity. The proposed structure can significantly enhance the plasmonic activity in a wide range of incident light and enlarge working wavelength of absorbance in the range of near-UV, visible and near-infrared. We show that the sensitivity of the PASNB arrays reveals a linear relationship with the thickness of Ag-shell nano-bead (ASNB) for both the anti-bonding and bonding modes in the absorbance spectra. The broadband of absorbance spectra could be expanded as a wide range by varying the thickness of ASNB while the particle size is kept constant. Simulation results suggest this alternative scheme to the design and improvements on plasmonic enhanced TFSCs can be extended to other nanophotonic applications. 相似文献
The LAR family Protein Tyrosine Phosphatase sigma (PTPσ) has been implicated in neuroendocrine and neuronal development, and
shows strong expression in specific regions within the CNS, including the subventricular zone (SVZ). We established neural
stem cell cultures, grown as neurospheres, from the SVZ of PTPσ knockout mice and sibling controls to determine if PTPσ influences
the generation and the phenotype of the neuronal, astrocyte and oligodendrocyte cell lineages. 相似文献
Extended t-t'-t"-J-U models in which the second-nearest-neighbor hopping (t') and third-nearest-neighbor hopping (t") are included are studied using renormalized mean field theory. The models are meant to be low-energy effective models for the Hubbard models, and hence the Heisenberg exchange integral J and Hubbard repulsion U are related by J = 4t(2)/U. The trial wavefunctions for the ground states are partially Gutzwiller projected Hartree-Fock states. The Gutzwiller projection is implemented by means of a Gutzwiller approximation, and the site double occupancy d is taken as a variational parameter. It is found that a large |t'/t| narrows the band filling range that sustains antiferromagnetism (AFM) in the ground state, enhances the d-wave singlet superconductivity (dSC) in hole overdoped systems, but suppresses the dSC in electron overdoped systems. For a system that has large |t'/t| and |t"/t'|, the superconductivity (SC) at the onset of AFM in hole doped band filling is strongly suppressed. On the excitation occurring, when an electron doped system simultaneously contains SC and AFM, the system is found to have a nodeless gap at the Fermi level. Finally, the result of this study is related to experiments on the superconducting cuprates. 相似文献
Inertial confinement fusion, frequently referred to as ICF, inertial fusion, or laser fusion, is a means of producing energy
by imploding small hollow microspheres containing thermonuclear fusion fuel. Polymer microspheres, which are used as fuel
containers, can be produced by solution-based micro-encapsulation technique better known as density-matched emulsion technique. The specifications of these microspheres are very rigorous, and various aspects of the emulsion hydrodynamics associated
with their production are important in controlling the final product. This paper describes about the optimization of various
parameters associated with density-matched emulsion method in order to improve the surface smoothness, wall thickness uniformity
and sphericity of hollow polymer microspheres. These polymer microshells have been successfully fabricated in our lab, with
3–30 μm wall thickness and 50–1600 μm diameters. The sphericity and wall thickness uniformity are better than 99%. Elimination
of vacuoles and high yield rate has been achieved by adopting the step-wise heating of W1/O/W2 emulsion for solvent removal. 相似文献