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101.
Summary We report the measurements of the3
D(3s4d)-3
P(3s3p)3
D(3s5d)-3
P(3s3p), and3
P(3p
2)-3
P(3s3p) transition frequency of MgI, the fine-structure separation and isotope shift between24Mg and26Mg. The measurements have been performed in a metastable atomic beam; a good agreement is found for data already existing
in the literature. The accuracy of the measurements reported in this paper is mainly limited by the Doppler broadening of
theI
2 transitions used as a reference and by the precision in the knowledge of the related wavelengths. 相似文献
102.
Fernando Cobos Christian Richter Tino Ullrich 《Journal of Mathematical Analysis and Applications》2009,352(2):773-787
We study spaces generated by applying the interpolation methods defined by a polygon Π to an N-tuple of real interpolation spaces with respect to a fixed Banach couple {X,Y}. We show that if the interior point (α,β) of the polygon does not lie in any diagonal of Π then the interpolation spaces coincide with sums and intersections of real interpolation spaces generated by {X,Y}. Applications are given to N-tuples formed by Lorentz function spaces and Besov spaces. Moreover, we show that results fail in general if (α,β) is in a diagonal. 相似文献
103.
N. Poli M. G. Tarallo M. Schioppo C. W. Oates G. M. Tino 《Applied physics. B, Lasers and optics》2009,97(1):27-33
Existing optical lattice clocks demonstrate a high level of performance but they remain complex experimental devices. In order
to address a wider range of applications including those requiring transportable devices, it will be necessary to simplify
the laser systems and reduce the amount of support hardware. Here we demonstrate two significant steps towards this goal:
demonstration of clock signals from a Sr lattice clock based solely on semiconductor laser technology, and a method for finding
the clock transition (based on a coincidence in atomic wavelengths) that removes the need for extensive frequency metrology
hardware. Moreover, the unexpected high contrast in the signal revealed evidence of density dependent collisions in 88Sr atoms. 相似文献
104.
The application of learning machine techniques to the interpretation of mass spectra is investigated. An attempt to improve the characteristic ratio of the number of training points to the number of adjustable parameters is made by the use of reduced spectra. The ensuing results are corrected for the unequal representation of the different substances in the data bank. Reasonable performance is obtained for spectra of simple (monofunctional) substances, but predictive abilities are poor for more complicated substances. 相似文献
105.
The molar volumes of mixtures of perdeuteriated and protiated heptane have been measured between -10° and 40° and expressed as a second order polynomial of the weight fraction. The difference in molar volumes of about 0.4 ml/mol decreases with temperature. The possibility of using the density measurement to determine the degree of deuteriation of mixtures of partially deuteriated heptanes was examined. The percent deuteriation calculated by this method deviates systematically from the true values. 相似文献
106.
Tino Ahrens 《International Journal of Theoretical Physics》1984,23(2):185-194
Spin-1 fields are constructed automatically using the regular representation of the three-dimensional complex orthogonal group and the group's isomorphism with the Lorentz group. The fields and potentials are examined as one lets their mass go to zero. Going to masslessness after the differentiation of potentials results in a consistent formulation of the fields. The behavior of the massive and massless potentials under rotations in the particle frame is examined. The loss of global degrees of freedom as one goes from one to the other is made up by the appearance of gradient terms. 相似文献
107.
The relative rates of competing metastable decompositions of fourteen isomeric C7H14 monoolefins were measured and compared. In every case except one the most important metastable reaction was loss of either CH3 or C2H4, but the rates of these and the other reactions observed varied over a wide range. It was concluded that the molecular ions of these compounds probably do not isomerize to a common structure prior to metastable decay. It was found that a terminal double bond strongly enhances metastable loss of C2H4 and that the additional presence of a 2-methyl substituent favours this reaction still more. Several possible mechanisms for this transition are discussed, but none was found to explain the observed results satisfactorily. 相似文献
108.
A method, using the radiolysis of an alkane, for the obtention of a great number of branched hydrocarbons is given. The retention index at 100° as well as its variation with temperature is determined on Apiezon L for 200 alcanes containing between seven and twenty four carbons. It is shown that for branched hydrocarbons the decrease of the retention index is mainly due to the length of the substituent group but also to its position on the chain. Some rules between retention index and molecular structure are deduced that allow the determination of the index of higher branched hydrocarbons. It is also shown that the variation of the retention index with temperature is only a function of the length of the substituent group. 相似文献
109.
Hydrogen, cycloalkene, and bicycloalkyl were found to be the principal products which account for ≈?97% of all products formed in the gas-phase radiolysis of water vapor containing low concentrations of cycloalkanes. From the ratios of cycloalkene-to-bicycloalkyl yields extrapolated to the zero dose, the self- and cross-disproportionation-to-recombination rate constant ratios Δ = kd/kc were determined for the following 12 reactions: Δ(c-C5H9, c-C5H9) = 0.73; Δ(c-C5D9, c-C5D9) = 0.58; Δ(c-C6H11, cC6H11) = 0.59; Δ(c-C6D11, c-C6D11) = 0.46; Δ(c-C5H9, c-C6H11) = 0.28; Δ(c-C5D9, c-C6H11) = 0.28; Δ(c-C5H9, c-C6D11) = 0.24; Δ(c-C5D9, c-C6D11) = 0.24; Δ(c-C6H11, c-C5H9) = 0.33; Δ(c-C6H11, c-C5D9) = 0.25; Δ(c-C6D11, c-C5H9) = 0.35; and Δ(c-C6D11, c-C5D9) = 0.28, where in the case of the cross-disproportionation the symbol Δ(R1,R2) is used to represent kd/kc for the disproportionation in which radical R1 captures a hydrogen (deuterium) atom from radial R2. The geometrical mean rule holds in the cross-combination reactions of cyclopentyl and cyclohexyl radicals. The kinetic isotope effect in the disproportionation reaction was determined as 1.24 ± 0.06. 相似文献
110.
Contributions of radical and non-radical processes have been determined in the formation of radiolysis products of n-heptane, n-octane, n-nonane and n-decane in a large range of temperature. Calculations are based on the combination and the dismutation of radicals, both reactions having nearly the same importance. Hydrogen abstraction reactions become important above – 25°. Intermediate molecular weight products and dimers are formed by statistical combination of the various radicals resulting from C? C and C? H scission. At low temperature, low molecular weight products are formed by both radical and non-radical processes, the second one being more important (3/4 for alcanes and 2/3 for olefins). The yield of radicals increases with the chain length of the irradiated n-alkane and amounts to 4.5 for n-heptane and 6.8 for n-decane at – 25°. This increase is due only to radicals from C? H scission, while the yield of radicals from C? C scission remains constant. Scission of CH2? CH2 bonds is favored for bonds inside the molecule, but this affect diminishes with chain length and CH2? CH2 rupture is equally probable at all positions for n-alcanes heavier than decane. Methyl C? H scission is 2.7 times less probable than methylene C? H scission. The radiolysis of mixtures of protonated and deuterated n-alcanes is shown to be able to give information concerning basic processes in radiation chemistry. 相似文献