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1.
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.
A least-squares method in the matrix form is described for the simultaneous determination of rifampicin and isoniazid in a mixture. The method allows the rapid analysis of binary pharmaceutical formulations with minimum error. The concentration of each component in the mixture has been determined spectrophotometrically by measuring the absorbance of the mixture at 5-nm intervals from 230 to 290 nm. To calculate the matrix of the proportionality constant a standard mixture was used for each component. All data analyses were performed on a personal computer. 相似文献
3.
G.B. Mpango K.K. Mahalanabis Z. Mahdavi-Damghani V. Snieckus 《Tetrahedron letters》1980,21(50):4823-4826
1,4-Addition of RLi, RMgX, and (RS) 2CHLi reagents to unsaturated amides 2a-c followed by α-alkylation is shown to constitute a general and efficient synthetic procedure for the formation of two CC bonds in a single step. 相似文献
4.
Acid catalysed dehydration of the diols 5 , derived from the cyclohexenone 3 affords mixtures of 8 and 11 . The product ratio 8/11 , although strongly dependent on both the reaction conditions and the substituent R, is independent of the diol configuration; this indicates a cationic intermediate 6 . Conditions were found, which allow the sequence A → B → C → D (Scheme 2) to be applied to the syntheses of the enones 8, 21 and 25 in fair to good yields from the corresponding cyclohexenones 3, 18 and 22 . 相似文献
5.
H. J. Pirner B. Kerbikov J. Mahalanabis 《Zeitschrift für Physik A Hadrons and Nuclei》1991,338(1):111-112
Low energyN¯N scattering is reanalyzed using the new data on annihilation cross-sections from CERN [1], the¯np-absorption measurement from BNL [2] and the annihilation width of the 2p state in antiprotonic hydrogen [3]. Imposing the condition that the imaginary part of the effective range is negative we find low energy scattering parameters which interpolate between the existing ITEP [4] and CERN/Heidelberg [5] values.Supported by the BMFT-grant 06 HD 756 相似文献
6.
7.
The racemic spirosesquiterpenes β-acorenol ( 1 ), β-acoradiene ( 2 ), acorenone-B ( 3 ) and acorenone ( 4 ) (Scheme 2) have been synthesized in a simple, flexible and highly stereoselective manner from the ester 5 . The key step (Schemes 3 and 4), an intramolecular thermal ene reaction of the 1,6-diene 6 , proceeded with 100% endo-selectivity to give the separable and interconvertible epimers 7a and 7b . Transformation of the ‘trans’-ester 7a to (±)- 1 and (±)- 2 via the enone 9 (Scheme 5) involved either a thermal retro-ene reaction 10 → 12 or, alternatively, an acid-catalysed elimination 11 → 13 + 14 followed by conversion to the 2-propanols 16 and 17 and their reduction with sodium in ammonia into 1 which was then dehydrated to 2 . The conversion of the ‘cis’-ester 7b to either 3 (Scheme 6) or 4 (Scheme 7) was accomplished by transforming firstly the carbethoxy group to an isopropyl group via 7b → 18 → 19 → 20 , oxidation of 20 to 21 , then alkylative 1,2-enone transposition 21 → 22 → 23 → 3 . By regioselective hydroboration and oxidation, the same precursor 20 gave a single ketone 25 which was subjected to the regioselective sulfenylation-alkylation-desulfenylation sequence 25 → 26 → 27 → 4 . 相似文献
8.
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
9.
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
10.
Jayanti Mahalanabis 《Zeitschrift für Physik A Hadrons and Nuclei》1992,342(1):101-105
The elementary ¯p-neutron amplitude has been obtained from Glauber's model analysis of ¯p-d elastic scattering data at 600 MeV/c, taking into account theD-state component of the deuteron. The results are compared with the ¯p-nucleus analysis and the ¯NN potential model predictions. 相似文献