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941.
A relativistic analysis of the rate of spin flips in ionization of an ensemble of Dirac H atoms subjected to intense circularly polarized laser fields is made. A remarkable intensity-dependent asymmetry between the spin up and spin down electron currents is found. It is nonzero even when the retardation effect, hence the magnetic component of the field, as well as the spin-orbit interaction responsible for the well-known Fano effect, is negligible. Transformation properties of the amplitudes show that the sign of asymmetry can be controlled by changing the helicity of the laser photons from outside. 相似文献
942.
In accordance with the US Code of Federal Regulations 21CFR 211.84 (6)(d)(1), a specific identity test must be performed for the release of chromatography media (stationary phase) before use in production of human pharmaceuticals. Due to the complexity of the physical and chemical properties of these media, i.e., variable particle morphology, insolubility, and chemical inertness, the development of specific identity tests presents a challenge. In this paper we report a new strategy for media identification that uses a combination of three relatively simple techniques: Fourier transform infrared (FT-IR) and near infrared (NIR) spectroscopy in conjunction with search libraries, and particle size distribution analysis. The methods are well established and suitable for routine application in a quality control laboratory. A hierarchical selection procedure utilizing these methods permits assignment of a unique identity for each of the chromatography media in use at a given facility, and form the basis of release tests for the media. Although this strategy was developed using specific media, the generic nature of the technology and the selection strategy proposed would permit its application to other chromatography media as well. 相似文献
943.
Anindita Bhattacharyya G. P. Raja Sekhar 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2005,56(3):475-496
An arbitrary Stokes flow of a viscous, incompressible fluid inside a sphere with internal singularities, enclosed by a porous spherical shell, using Brinkmans equation for the flow in the porous region is discussed. At the interface of the clear fluid and porous region stress jump boundary condition for tangential stresses is used. The drag and torque are found by deriving the corresponding Faxens laws. It is found that drag and torque not only change with the varying permeability, but also change for different values of stress jump coefficient. Critical permeability is found for which drag and torque change their behavior. As a limiting case the corresponding Faxens laws for the rigid spherical shell with internal singularities has been obtained.Received: December 17, 2002; revised: February 3, 2004 相似文献
944.
Bhattacharyya P Daly PJ Zhang CT Grabowski ZW Saha SK Broda R Fornal B Ahmad I Seweryniak D Wiedenhöver I Carpenter MP Janssens RV Khoo TL Lauritsen T Lister CJ Reiter P Blomqvist J 《Physical review letters》2001,87(6):062502
Prompt and delayed gamma-ray cascades in doubly magic 132Sn and its neighbor 131Sn have been studied at Gammasphere using a 248Cm fission source. Isotopic assignments of unknown gamma rays were based on coincidences with known transitions in A = 112-116 Pd fission partners. The yrast level spectra of both tin nuclei are interpreted using empirical nucleon-nucleon interactions from the 132Sn and 208Pb regions. Results include identification of the (nuf(7/2)h(-1)(11/2))9(+) aligned state in 132Sn and of extensive (nuf(7/2)h(-2)(11/2)), (nuf(7/2)d(-1)(3/2)h(-1)(11/2)) and (nuh(-1)(11/2)x3(-)) multiplets in 131Sn. The previously reported beta(-) decay of an unusual 131In high-spin isomer to levels in 131Sn is also elucidated. 相似文献
945.
Suppose thatA
1,A
2, ...,A
n are compact commuting self-adjoint linear maps on a Pontryagin spaceK of indexk and that their joint root subspaceM
0 at the zero eigenvalue in
n
is a nondegenerate subspace. Then there exist joint invariant subspacesH andF inK such thatK=FH,H is a Hilbert space andF is finite-dimensional space withkdimF(n+2)k. We also consider the structure of restrictionsA
j|F in the casek=1. 相似文献
946.
Dipankar Bhattacharyya Ayan Ray Bibhas K. Dutta Pradip N. Ghosh 《Optics & Laser Technology》2002,34(1):93-96
It is shown that Fizeau interferometry provides an accurate optical method to measure the refractive index and wedge angle of transparent plates used as optical components in different experiments. A near IR external cavity diode laser having spectral resolution up to 10−7 has been employed to measure the refractive index of the test plates by introducing amplitude modulation technique in the detection system of our phase shifting Fizeau interferometry. Detection of spatial fringes has been performed to find out the wedge angles of the plates by using a He–Ne laser along with the CCD-image sensor. 相似文献
947.
Costunolide, the new sesquiterpene lactone isolated from costus root oil (Saussurea lappa Clarke) is shown to have the structure I on the basis of dehydrogenation, ozonolyses and the formation of santanolide 'C' under mild conditions. 相似文献
948.
949.
This note reports the detection of fluorescence from unrelaxed S1 state of benzil using Boxcar gating technique. The new emission exhibits mirror image relationship with absorption and blue shift in hydroxylic solvent. In order to ascertain wheter geometrical relaxation occurs in S1 state, intensities of fluorescence from relaxed and unrelaxed state have been compared at various temperatures. 相似文献
950.
B.S. Shaibu M.L.P. Reddy A. Bhattacharyya V.K. Manchanda 《Journal of magnetism and magnetic materials》2006
In the magnetically assisted chemical separation (MACS) process, tiny ferromagnetic particles coated with solvent extractant are used to selectively separate radionuclides and hazardous metals from aqueous waste streams. The contaminant-loaded particles are then recovered from the waste solutions using a magnetic field. The contaminants attached to the magnetic particles are subsequently removed using a small volume of stripping agent. In the present study, Cyanex 923 (trialkylphosphine oxide) coated magnetic particles (cross-linked polyacrylamide and acrylic acid entrapping charcoal and iron oxide, 1:1:1, particle size=1–60 μm) are being evaluated for the possible application in the extraction and separation of lanthanides and actinides from nuclear waste streams. The uptake behaviour of Th(IV), U(VI), Am(III) and Eu(III) from nitric acid solutions was investigated by batch studies. The effects of sorption kinetics, extractant and nitric acid concentrations on the uptake behaviour of metal ions were systematically studied. The influence of fission products (Cs(I), Sr(II)) and interfering ions including Fe(III), Cr(VI), Mg(II), Mn(II), and Al(III) were investigated. The recycling capacity of the extractant-coated magnetic particles was also evaluated. 相似文献