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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 →ν
τ 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
2.
Rare earth element substituted bismuth ferrites (BiFeO3) are of enormous importance as magnetoelectric materials. The polycrystalline samples of Bi
x
La1−x
FeO3 (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
3.
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
4.
David L Kirkham Laura KK Pacey Michelle M Axford Roberta Siu Daniela Rotin Laurie C Doering 《BMC neuroscience》2006,7(1):50-9
Background
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5.
Fabrication of polystyrene hollow microspheres as laser fusion targets by optimized density-matched emulsion technique and characterization 总被引:3,自引:0,他引:3
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
6.
Tatineni R Doddapaneni KK Potumarthi RC Mangamoori LN 《Applied biochemistry and biotechnology》2007,141(2-3):187-201
A two-step response surface methodology (RSM) study was conducted for the optimization of keratinase production and enzyme
activity from poultry feather byStreptomyces sp7. Initially different combinations of salts were screened for maximal production of keratinase at a constant pH of 6.5
and feather meal concentration of 5 g/L. A combination of K2HPO4, KH2PO4, and NaCl gave a maximum yield of keratinase (70.9 U/mL) production. In the first step of the RSM study, the selected five
variables (feather meal, K2HPO4, KH2PO4, NaCl, and pH) were optimized by a 25 full-factorial rotatable central composite design (CCD) that resulted in 95 U/mL of keratinase production. The results of
analysis of variance and regression of a second-order model showed that the linear effects of feather meal concentration (p<0.005) and NaCl (p<0.029) and the interactive effects of all variables were more significant and that values of the quadratic effects of feather
meal (p<1.72e-5), K2HPO4 (p<4.731e-6), KH2PO4 (p<1.01e-10), and pH (p 7.63e-7) were more significant than the linear and interactive effects of the process variables. In the second step, a 23 rotatable full-factorial CCD and response surface analysis were used for the selection of optimal process parameters (pH,
temperature, and rpm) for keratinase enzyme activity. These optima were pH 11.0, 45°C, and 300 rpm. 相似文献
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