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991.
992.
The collapse in a quantum-mechanical measurement is treated as a physical process, described by a superoperator mapping states into states and depending only on the measured observable. The assumption that the states with a sharp value of the measured observable remains unchanged yields the Lüders-Von Neuman formula. 相似文献
993.
W. Ruckstuhl B. Aas W. Beer I. Beltrami K. Bos G. De Chambrier P.F.A. Goudsmit H.J. Leisi G. Strassner A. Vacchi J.M. Van Der Velden B. Jeckelmann U. Kiebele R. Weber 《Nuclear Physics A》1985,433(4):634-648
The magnetic hyperfine splitting (h.f.s.) in the 1s state of 7Li has been measured with a precision of 1% using the bent-crystal spectrometer facility at the SIN muon channel. With an instrumental resolution of 2.5 eV FWHM the h.f.s. was completely resolved in the 2p-1s transition. The result is ΔE(M1) = 4684 ± 49meV. A comparison of this result with the electromagnetic value yields a new upper limit for the strength of a possible muon-nucleon interaction mediated by an axial-vector boson, which is much lower than those that can be derived from other present data. 相似文献
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998.
Gennady I. Nikishin Emmanuil I. Troyansky Igor V. Svitanko Oleg S. Chizhov 《Tetrahedron letters》1984,25(1):97-98
N-Methylpentanehydroxamic acid (N-methyl-N-pentanoylhydroxylamine) 1 rearranges into N-methyl-O-pentanoylhydroxylamine 2 through spontaneous N→O acyl migration. 相似文献
999.
Andreas Weber Gabriele Sabbioni Roberto Galli Urs Stmpfli Markus Neuenschwander 《Helvetica chimica acta》1988,71(8):2026-2033
Synthesis of Triafulvene-Precursors from Trisubstituted Cyclopropanes Trisubstituted cyclopropanes 5a–f are prepared by carbene addition to the appropriate olefins. While 5a (Y = OAc) and 5c (Y = Cl) rearrange in the presence of BuLi, 5d (Y = SPh) is stable enough to allow the envisaged sequence for triafulvene (Scheme 2) : halogen-Li exchange, followed by methylation of 6d , gives 7d in a 93% yield; after base-induced elimination of HB r from 7d , the key precursor 1-methylene-2-(phenylthio)cyclopropane ( 9 , 70% yield) is isolated. Compound 9 is transformed into the corresponding sulfoxide 10 (83%), sulfone 11 (80%), and sulfonium fluoroborate 12 (95% yield) by subsequent oxidation and methylation, respectively. Some 1H-NMR results of cyclopropanes 5a–f and 7d as well as of methylidene-cyclopropanes 9–11 are discussed. 相似文献
1000.
Complex Formation of N-(Thiocarbamoyl) benzamidines N-(Thiocarbamoyl)benzamidines 1 and N-(Thiocarbamoyl)-N′-phenyl-benzamidines 2 form in alcoholic solutions with Ni2+, Cu2+, Pd2+, Co3+, and Ag+ ions well crystallized chelates 1a ? h and 2a? h , respectively, with N/S coordination. The X-ray photoelectron spectra evidence the NH group as ligator in the case of chelates of 1 and the increased donor capacity compared with the isosteric oxygen ligator atom bound to nickel. This is confirmed by d-1H-n.m.r. spectroscopy analyzing the value of ΔGc≠ for the rotational barrier for the Et2N group of 1a 相似文献