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21.
Wolfgang Reich Terry S. Bright Wolfgang Malisch Carl Kruger 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract The reaction of the metal phosphorus double bonded species Cp(CO)2M=PR2 (M = Mo, W; R = aryl, alkyl) (1)1) with diverse diazoalkanes, alkenes, alkines and dienes results in the facile formation of the [2+1]-, [2+2]1- and [2+4]-cycloaddition products 2a-c. 相似文献
22.
Oppenauer oxidation constitutes a mild, often selective, procedure for the conversion of alcohols to aldehydes or ketones.1 In many instances a ketone higher boiling than acetone must be used to facilitate the reaction. The excess ketone and the corresponding alcohol, owing to a relatively low volatility and high solubility in organic solvents, are frequently difficult to separate from the desired product. For example, cyclohexanone and cyclo-hexanol are commonly removed by steam distillation, a somewhat tedious procedure not amenable to certain sensitive compounds. 相似文献
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Simeon Reich Alexander J. Zaslavski 《Journal of Fixed Point Theory and Applications》2010,8(2):395-403
We use the concept of porosity in order to establish a generic stable convergence theorem for infinite products of nonexpansive
mappings in Banach spaces. 相似文献
25.
We present several results concerning the asymptotic behavior of (random) infinite products of generic sequences of positive linear operators on an ordered Banach space. In addition to a weak ergodic theorem we also obtain convergence to an operator of the formf(·) wheref is a continuous linear functional and is a common fixed point. 相似文献
26.
R.C. Greenwood C.W. Reich H.A. Baader H.R. Koch D. Breitig O.W.B. Schult B. Fogelberg A. B?cklin W. Mampe T. Von Egdy K. Schreckenbach 《Nuclear Physics A》1978,304(2):327-428
The level structure of 158Gd has been studied using the prompt γ-rays and conversion electrons emitted following neutron capture in 157Gd. The γ-ray energy and intensity measurements were made using both Ge(Li) detectors and a curved-crystal spectrometer. Conversion-electron energy and intensity measurements were made using two separate magnetic spectrometers: one to measure the primary electron spectrum and the other to measure the lower energy secondary electron spectrum. Some γ-γ coincidence measurements were also made among the secondary γ-rays. From these data, a neutron separation energy of 7937.1 ± 0.5 keV has been determined for 158Gd. A level scheme containing 59 excited states with energies < 2.25 MeV, for which de-excitation modes have been identified, is proposed for 158Gd. Many of these states have been grouped into rotational bands. A total of thirteen excited rotational bands with band-head energies below 2.0 MeV are contained in the level scheme. Features of the proposed level scheme include: the Kπ = 0?, 1? and 2? octupole-vibrational bands with band-head energies of 1263, 977 and 1793 keV, respectively; the γ-vibrational band at 1187 keV; three excited Kπ = 0+ bands with band-head energies of 1196, 1452 and 1743 keV; several two-quasiparticle bands with band-head energies in keV (and Kπ assignments) of 1380 (4+), 1636 (4?), 1847 (1+), 1856 (1?), 1920 (4+) and 1930 (1+). An analysis of (d, p) reaction data is presented which permits definite two-quasiparticle configuration assignments to be made to most of these latter bands. Evidence is presented which suggests strong mixing of some two-neutron and two-proton bands. A phenomenological four-band mixing analysis is made of the energy and E2 transition-probability data for the ground-state band and the three lowest-lying excited collective positive-parity bands. Good agreement with experiment is obtained. A Coriolis-mixing analysis of the octupole bands has been carried out and good agreement with the data on level energies and E1 transition probabilities to the ground-state band has been achieved. Values of Z, the ratio of the E1 transition matrix element with ΔK = 1 to that with ΔK = 0, involving the octupole bands and the first four 0+ bands are derived. For three of these 0+ bands, absolute values of these matrix elements are deduced. An interesting alternation in the sign of Z is observed for these four 0+ bands. 相似文献
27.
The β-spectrum of the second non-unique forbidden 9/2+?5/2+ transition in the decay of99Tc has been investigated with a 4π – Si (Li)-semiconductor-spectrometer. The shape factor has been determined: S(W)=k (1?3.97 W+1.15/W+3.05 W2). It was also possible to fit the data with the normal ξ-Approximation to the theoretical shape factorS(W)=k(q12+0.54 p2). The second forbidden 2+? 0+ β?-transition in the decay of36Cl was reinvestigated to test the spectrometer as well as the fitting-technique. 相似文献
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29.
Stohlker T Mokler PH Bosch F Dunford RW Franzke F Klepper O Kozhuharov C Ludziejewski T Nolden F Reich H Rymuza P Stachura Z Steck M Swiat P Warczak A 《Physical review letters》2000,85(15):3109-3112
The Lyman- alpha transitions of hydrogenlike uranium associated with electron capture were measured in collisions of stored bare U (92+) ions with gaseous targets at the storage ring ESR. By applying the deceleration technique, the experiment was performed at slow collision energies in order to reduce the uncertainties associated with Doppler corrections. From the measured centroid energies, a ground state Lamb shift of 468 eV+/-13 eV is deduced which gives the most precise test of quantum electrodynamics for a single electron system in the strong field regime. In particular, the technique applied paves the way towards the 1 eV precision regime. 相似文献
30.