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1.
The time delay experiment proposed by I.I. Shapiro in 1964 and conducted in the seventies was the most precise experiment
of general relativity until that time. Further experimentation has improved the accuracy level of both the time delay and
the light deflection experiments. A simulation model is proposed that involves only a simple mass and time transformation
factor involving velocity of light. The light deflection and the time delay experiments are numerically simulated using this
model that does not use the general relativistic equations. The computed values presented in this paper compare well with
recent levels of accuracy of their respective experimental results. 相似文献
2.
Rahul P. Dixit Chandrashekhar R. Barhate Mangal S. Nagarsenker 《Chromatographia》2008,67(1-2):101-107
Simvastatin and ezetimibe are used to treat hyperlipidemia. A simple, selective and stability-indicating HPTLC method has
been established for analysis of simvastatin and ezetimibe. The method has been validated so that both drugs can routinely
be analyzed simultaneously. The method uses aluminum-backed silica gel 60F254 TLC plates as stationary phase with n-hexane–acetone 6:4 (v/v) as mobile phase. Densitometric analysis of both drugs was carried out in absorbance mode at 234 nm. This system was found
to give compact bands for simvastatin and ezetimibe (R
F 0.39 ± 0.05 and 0.50 ± 0.05, respectively). Linear relationships were obtained between response and amount of drug in the
range 200–1,600 ng per band with high correlation coefficients (r
2 = 0.9917 ± 0.0018 for simvastatin and r
2 = 0.9927 ± 0.0021 for ezetimibe). The method was validated for precision, robustness, and recovery. The limits of detection
and quantitation were 25 and 150 ng per band, respectively. Simvastatin and ezetimibe were subjected degradation by acid,
pH 6.8 phosphate buffer, oxidation, dry heat, and wet heat. The degradation products were well resolved from the pure drug
with significantly different R
F values. Because the method could effectively separate the drug from its degradation products, it can be used for stability-indicating
analysis. 相似文献
3.
Desai Neha S. Barhate Chandrashekhar R. Biyani Sheetal O. Kulkarni Savita R. Nagarsenker Mangal S. 《平面色谱法杂志一现代薄层色谱法》2011,24(4):306-311
JPC – Journal of Planar Chromatography – Modern TLC - Annona squamosa, commonly known as custard apple, possesses various medicinal properties such as antimicrobial, insecticidal,... 相似文献
4.
A nucleoside carrying a perfluorinated tert-butyl group ( 4) was prepared by a Sonogashira coupling of 5-iodo-2'-deoxyuridine with 4,4,4-trifluoro-3,3-bis(trifluoromethyl)-1-butyne in nearly quantitative yield and subsequently incorporated into DNA oligomers. Thermal denaturation studies showed that 4 had a negligible effect on duplex stability when compared to thymidine. Transition from single strand to duplex was monitored by (19)F NMR spectroscopy at micromolar concentrations of oligomers, demonstrating the sensitivity of 4 as an NMR reporter nucleoside. 相似文献
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We present two new variants of Schur complement domain decompositionpreconditioners suitable for 2D anisotropic problems. Thesevariants are based on adaptations of the probing idea, describedby Chan et al (1992 Fifth Int. Symp. on Domain DecompositionMethods for Partial Differential Equations, Philadelphia: SIAM,pp 236-249), used in conjunction with a coarse grid approximationas introduced by Bramble et al (1986 Math. Comput. 47, 103-134).The new methods are specifically designed for situations wherethe coupling between neighbouring interfaces is stronger thanthe coupling within an interface. Taking into account this strongcoupling, one variant uses a multicolour probing technique toavoid distortion in the probe approximations that appear whenusing the method proposed by Chan et al. The second techniqueuses additional probe matrices to approximate not only the couplingwithin the interfaces but also the coupling between interfacepoints across the subdomains. This latter procedure looks somewhatlike an alternating line relaxation method for anisotropic problems,see Brandt (1977 Math. Comput.. 31, 333-390). To assess therelevance of the new preconditioners, we compare their numericalbehaviour with well known robust preconditioners such as thebalanced Neumann-Neumann method proposed by Mandel (1993 Commun.Numer. Methods Eng.. 9, 233-241). 相似文献
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9.
The ‘anomalous perihelion precession’ of Mercury, announced by Le Verrier in 1859, was a highly controversial topic for more
than half a century and invoked many alternative theories until 1916, when Einstein presented his theory of general relativity
as an alternative theory of gravitation and showed perihelion precession to be one of its potential manifestations. As perihelion
precession was a directly derived result of the full General Theory and not just the Equivalence Principle, Einstein viewed
it as the most critical test of his theory. This paper presents the computed value of the anomalous perihelion precession
of Mercury's orbit using a new relativistic simulation model that employs a simple transformation factor for mass and time,
proposed in an earlier paper. This computed value compares well with the prediction of general relativity and is, also, in
complete agreement with the observed value within its range of uncertainty. No general relativistic equations have been used
for computing the results presented in this paper. 相似文献
10.
Extraction using aqueous two-phase systems (ATPSs) is a versatile technique for the downstream processing of various proteins/enzymes. The study of drop formation deals with the fundamental understanding of the behavior of liquid drops under the influence of various external body as well as surface forces. These studies provide a basis for designing of the extractions in column contactors in which liquid drops play a major role. Most of the drop formation studies reported so far is restricted to aqueous-organic systems. ATPSs, differ from aqueous-organic systems in their physical properties. In view of this, an attempt was made to develop a model for drop formation in ATPSs adopting the information available on aqueous-organic systems. In order to validate the model, experiments were performed by using polyethylene glycol (PEG)/salt systems of different phase compositions at various flow rates. At low flow rates the single stage model and at high flow rates the two stage model are able to predict the drop volume during its formation from tip of capillary. The experimental results were found to agree reasonably well with those predicted by the model. 相似文献