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81.
Malcolm S. Cresser Anthony C. Edwards 《Spectrochimica Acta Part B: Atomic Spectroscopy》1984,39(4):609-612
The operating pressure of a pneumatic nebulizer has been measured. The rsult has been used to explain the problems associated with the variation in flame spectroscopy signal with sample position when a capillary T piece is used for continuous addition of releasing agent. The way to minimize this variation is outlined. 相似文献
82.
D.M. Edwards 《Journal of magnetism and magnetic materials》1984,45(1):151-156
It is shown how disordered local-moment states, in a metal such as Fe, may be stabilized by constraining magnetic fields. Effective interaction parameters between moments are defined in terms of spin density functional theory. On removing the constraints the moments initially precess but then decay rapidly, the latter process leading to an energy width of S(q, ω) at large q of order , where TC is the Curie temperature and W is the width of the d-band. T he consequences for neutron scattering experiments are discussed and the rather different case of Ni is considered. 相似文献
83.
The high resolution phase diagram of the tetramethylammonium heptadecafluorononanoate (TMAHFN)/D2O system has been mapped out using 2H and 14NNMR spectroscopy. The 14N quadruple splittings are more than an order of magnitude larger than corresponding 2H splittings, while the line widths are only two to three times larger. Thus, 14NNMR offers an order of magnitude improvement over 2H NMR in the resolution of the spectra from coexisting phases. The 2H spectra of samples in biphasic regions are often complicated by chemical exchange of D2O molecules between coexisting phases, particularly at low TMAHFN concentrations. Analysis of the 2H line shapes of a TMAHFN/D2O sample with a weight fraction of TMAHFN of 0.230 obtained at various times following cooling of the sample into the isotropic/nematic biphasic region shows that the mean diameter for the dispersed nematic droplet grows from about 7 to about 26 μm over a period of 2 h. At a mean droplet size of 7 μm the exchange of TMA+ ions between the coexisting phases is slow on the NMR time-scale and exchange effects are not observed in 14N spectra. The TMAHFN/D2O phase diagram exhibits the generic form of those of the CsPFO/water and APFO/D2O systems, which are the only other systems composed of stable discotic micelles for which high resolution phase diagrams are currently available, but the nematic phase is displaced to smaller TMAHFN concentrations. Specifically, a discotic nematic phase ND+, intermediate between an isotropic micellar phase I and a lamellar phase L, exists for weight fractions of TMAHFN between 0.149 (φ = 0.105) and 0.420 (φa = 0.325) and temperatures between 277.3 and 327.6 K. 相似文献
84.
A stereospecific elimination process has been developed for introducing the E-ethylidene group in a transformation of tryptamine into methyl (±)-geissoschizoate. 相似文献
85.
David A. Edwards 《International Journal of Theoretical Physics》1981,20(7):503-517
In this paper we explore the mathematical foundations of quantum field theory. From the mathematical point of view, quantum field theory involves several revolutions in structure just as severe as, if not more than, the revolutionary change involved in the move from classical to quantum mechanics. Ordinary quantum mechanics is based upon real-valued observables which are not all compatible. We will see that the proper mathematical understanding of Fermi fields involves a new concept of probability theory, the graded probability space. This new concept also yields new points of view concerning ergodic theorems in statistical mechanics. 相似文献
86.
87.
P.J. Bussey C. Raine J.G. Rutherglen P.S.L. Booth L.J. Carroll G.R. Court P.R. Daniel A.W. Edwards R. Gamet C.J. Hardwick P.J. Hayman J.R. Holt J.N. Jackson W.H. Range F.H. Combley W. Galbraith V.H. Rajaratnam C. Sutton 《Nuclear Physics B》1979,154(3):492-502
The polarisation parameters Σ, P and T have been measured for the process γp→π0p in the photon energy range 1300–2100 MeV and c.m. angles between 30° and 110°, in an experiment with a polarised beam and polarised target. The results are compared with a recent theoretical analysis which fits data from threshold to 16 GeV. The new data are in general agreement with the analysis, but with some significant discrepancies in detail. 相似文献
88.
We have run the high-resolution infrared absorption spectrum of 2ν2, ν1, and ν3 of H2Se in the region 5.2 to 3.8 μm. We have identified and fitted approximately 520 transitions in 2ν2, 930 transitions in ν1, and 620 transitions in ν3. Included are transitions from the isotopic species containing selenium isotopes 82, 80, 78, 77, and 76. Using Typke's rotational Hamiltonian, we analyzed all isotopic species simultaneously. Ground-state constants were determined from a simultaneous least-squares fit of 879 distinct ground-state combination differences formed from our data and 109 microwave transitions. Upper-state constants were obtained from least-squares fits of our spectral lines analyzing 2ν2 as a single noninteracting band and analyzing the Coriolis interacting bands ν1 and ν3 simultaneously, keeping the ground-state constants fixed. 相似文献
89.
For Newtonian fluids, the engineering predictions for pressure drop in turbulent pipe flow are well established. However, in the case of non-Newtonian liquids, only a few design techniques have been proposed and these do not share a common basis with the approach for Newtonian systems. This present work attempts to provide a common basis for both Newtonian and non-Newtonian systems in situations where anomalous wall effects are absent. Previously published experimental data suggest that if the Reynolds number is calculated on the basis of the apparent viscosity at the wall then the standard Newtonian correlations can be used for the prediction of pressure drop. The use of the wall viscosity in defining the Reynolds number also serves as a test for anomalous behaviour. Any departure of the experimental data from the Newtonian turbulent friction factor correlation indicates anomalous behaviour. 相似文献
90.