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51.
Triple differential cross-sections for the electron and positron impact ionization of atomic hydrogen and helium are calculated
in a first order model using a product of two Coulomb wavefunctions for the final state continuum electrons supplemented by
post-collision interaction effects. 相似文献
52.
53.
Using a spot size based optimization technique, a bend loss versus dispersion diagram has been obtained theoretically for the most widely used step-index disper sion compensated optical fibers (DCF). The Rayleigh scattering loss can be incorpo rated with bend loss to calculate figure of merit (FOM), thus giving an FOM versus dispersion curve on a single diagram. The plot of the FOM-dispersion curve on a single diagram is useful from the designer's point of view, as it provides a quick reference for choosing the best suitable DCF, which should have large negative dispersion as well as maximum possible value of FOM. The effect of fiber manufac turing losses such as absorption loss on the maximum value of FOM has also been estimated. 相似文献
54.
Changes of electronic charge distribution following the lowest singlet n–π* transitions of benzaldehyde, benzamide, benzoic acid, the phthalaldehydes, pyridine, and the diazines have been examined using the CNDO -S /CI method. A Singlet n–π* transition is found as a general rule to direct electronic charges to the para position of the atom in the ring that carries the lone pair or to which the substituent carrying the lone pair is attached. 相似文献
55.
Somenath Sarkar Arun Kumar I.C. Goyal Enakshi K. Sharma Ramanand Tewari 《Optics Communications》1985,53(2):91-94
We present an analytical method to evaluate the auxiliary function and spot sizes determining microbending loss in single mode fibers with arbitrary refractive index profiles. Comparison with the exact numerical results shows that the present method gives very accurate results for spot sizes. The method is simple and requires relatively less computational effort. 相似文献
56.
The linear condensed phosphates inhibit the development of color due to orthophosphatc by the method of LOWRY AND LOPEZ. The higher members of the scries (the polymetaphosphates) have more effect than the lower members (pyrophosphate, tripoly-and tetrapolyphosphates). The two cyclic metaphosphates, trimeta- and tetrametaphosphate, do not inhibit. The inhibition by polymetaphosphate is partly overcome by storing the developed color for about 90 min. Low concentrations of copper and nickel and higher concentrations of iron(III) remove either partially or completely the inhibition due to polymetaphosphates. None of the metaphosphates interferes in the estimation of orthophosphate by the isobutanol extraction method of BERENBLUM AND CHAIN 相似文献
57.
The calculated value of γ11, a neutron-condensed system energy observable, using the recent neutron scattering kernel proposed by the authors which incorporates explicitly chemical binding amongst the water molecules, turns out to be in much better agreement with the experimental result than that given by the widely used Nelkin kernel. Low energy collective oscillations, thus, play an important role in the dynamics of water. 相似文献
58.
Let G be a locally compact group with a fixed right Haar measure andX a separable Banach space. LetL
p
(G, X) be the space of X-valued measurable functions whose norm-functions are in the usualL
p
. A left multiplier ofL
p
(G, X) is a bounded linear operator onB
p
(G, X) which commutes with all left translations. We use the characterization of isometries ofL
p
(G, X) onto itself to characterize the isometric, invertible, left multipliers ofL
p
(G, X) for 1 ≤p ∞,p ≠ 2, under the assumption thatX is not thel
p
-direct sum of two non-zero subspaces. In fact we prove that ifT is an isometric left multiplier ofL
p
(G, X) onto itself then there existsa y ∃ G and an isometryU ofX onto itself such thatTf(x) = U
(R
y
f)(x). As an application, we determine the isometric left multipliers of L1 ∩L
p
(G, X) and L1 ∩C
0
(G, X) whereG is non-compact andX is not the lp-direct sum of two non-zero subspaces. If G is a locally compact abelian group andH is a separable Hubert space, we define
where г is the dual group of G. We characterize the isometric, invertible, left multipliers ofA
p
(G, H), provided G is non-compact. Finally, we use the characterization of isometries ofC(G, X) for G compact to determine the isometric left multipliers ofC(G, X) providedX
*
is strictly convex. 相似文献
59.
60.
Swarup Narain Tewari 《Fresenius' Journal of Analytical Chemistry》1961,180(2):109-110
Summary A paper chromatographic technique for the detection of arsenic, antimony and tin as applied to toxicological analysis has been described. 相似文献