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91.
The multiphoton ionization (MPI) spectrum of toluene arising from the 1B2 (1Lb) valence state has been investigated. The state participates as a two-photon resonance. A total of nine excited state fundamentals have been characterized, including three non-totally symmetric vibrations. The toluene MPI spectrum shows a strong resemblance to the two-photon fluorescence excitation spectrum with the strongest transitions taking place to the origin and excited state modes ν1(a1), ν12(a1) and ν14(b)2). The intensities of the observed fundamentals are rationalized in terms of Franck-Condon and vibronic coupling effects. A major conclusion is, that the primary mechanism for the activity of ν12 is vibronic coupling. 相似文献
92.
93.
W M Hartmann 《The Journal of the Acoustical Society of America》1984,75(2):528-535
A central spectrum explanation of the existence of the binaural edge pitch [Klein and Hartmann, J. Acoust. Soc. Am. 70, 51-61 (1981)] appears to require central lateral inhibition in the human auditory system. We have looked for this effect in central masking experiments. Using the binaural-edge noise, which creates the binaural edge pitch, as a masker (in standard notation: No below and N pi above a phase boundary frequency), we measured pulsation thresholds for sine tones in two frequency ranges where the binaural edge pitch exists. We also obtained reference data, using the same pulsation threshold technique, for standard binaural conditions NoSo, NoS pi, N pi So, and N pi S pi. These data revealed masking level differences. Theoretically the difference between the binaural-edge thresholds and the reference data should show the peak and valley signature of lateral inhibition. No such structure was found. We suggest that this negative result does not exclude the possibility of central lateral inhibition, but that the time course of central lateral inhibition makes the pulsation threshold technique an inappropriate means for observing the effect. 相似文献
94.
β-Amino-vinyl-selenoketones 9 react with aryl acetic acidchlorides 11, N-iminoformyl-arylacetic-imidchlorides 15 or derivatives of cyano acetic acid to give unknown 6-aryl-2-selenopyrones 14, 6-aryl-2-(N-formamidino)-selenopyrylium salts 16 or 6-aryl-2-amino-selenopyrylium salts 19. The compounds 19 were prepared from 3-(β-chloro-vinyl)-acrylonitriles 3 and NaHSe, too. 相似文献
95.
Luuk H. Karsten 《Physics letters. [Part B]》1981,104(4):315-319
A very short proof of a no-go theorem for putting fermions on a lattice is given using the Poincaré-Hopf theorem. The no-go theorem forbids the lattice formulation of theories with handed fermions without species doubling. Examples of such theories are chiral invariant QCD and the Weinberg-Salam-Glashow model. We give arguments why it could be possible to circumvent the no-go theorem by relaxing one of the assumptions, viz. bilinearity of the action in the fermion fields. 相似文献
96.
97.
Yaschenko S Dymov S Kacharava A Komarov V Macharashvili G Rathmann F Barsov S Gebel R Hartmann M Khoukaz A Kulessa P Kulikov A Kurbatov V Lang N Lehmann I Lorentz B Mersmann T Merzliakov S Mikirtytchiants S Mussgiller A Nioradze M Ohm H Prasuhn D Schleichert R Seyfarth H Steffens E Stein HJ Ströher H Uzikov Y Zalikhanov B Zhuravlev N 《Physical review letters》2005,94(7):072304
A measurement of the analyzing power A(y) of the p-->d--> (p p) + n reaction was carried out at the ANKE spectrometer at COSY at beam energies of 0.5 and 0.8 GeV by detection of a fast forward proton pair of small excitation energy E(pp) < 3 MeV. The S-wave dominance in the fast diproton is experimentally demonstrated in this reaction. While at T(p) = 0.8 GeV the measured analyzing power almost vanishes, it rises to nearly unity at T(p) = 0.5 GeV for neutrons emitted at theta(c.m.)(n) = 167 degrees. The results are compared with a model taking into account one-nucleon exchange, single scattering, and Delta(1232) excitation in the intermediate state. The model describes fairly well the unpolarized cross section obtained earlier and the analyzing power at 0.8 GeV; it fails to reproduce A(y) at 0.5 GeV. 相似文献
98.
Reisdorf W Andronic A Gobbi A Hartmann ON Herrmann N Hildenbrand KD Kim YJ Kirejczyk M Koczoń P Kress T Leifels Y Schüttauf A Tymiński Z Xiao ZG Alard JP Barret V Basrak Z Bastid N Benabderrahmane ML Caplar R Crochet P Dupieux P Dzelalija M Fodor Z Grishkin Y Hong B Kecskemeti J Korolija M Kotte R Lebedev A Lopez X Merschmeyer M Mösner J Neubert W Pelte D Petrovici M Rami F de Schauenburg B Seres Z Sikora B Sim KS Simion V Siwek-Wilczyńska K Smolyankin V Stockmeier M Stoicea G Wagner P 《Physical review letters》2004,92(23):232301
We present a complete systematics (excitation functions and system-size dependences) of global stopping and side flow for heavy ion reactions in the energy range between 0.09A and 1.93A GeV. For the heaviest system, Au+Au, we observe a plateau of maximal stopping extending from about 0.2A to 0.8A GeV with a fast drop on both sides. The degree of stopping, which is shown to remain significantly below the expectations of a full stopping scenario, is found to be highly correlated to the amount of side flow. 相似文献
99.
Using electron holography in a transmission electron microscope, we obtained direct evidence for the reduction of negative charge at grain boundary dislocations in Ca-doped YBa2Cu3O7 (YBCO) when compared to undoped YBCO. Because of the finite width of the valence band in the superconducting CuO2 planes, the negative grain boundary charge can lead to a depletion of electron holes available for superconductivity. A significant reduction in the size of the perturbed region in the Ca-doped samples appears to be the principal mechanism for the improved interfacial superconductivity. 相似文献
100.
Hartmann T Babilon M Kamerdzhiev S Litvinova E Savran D Volz S Zilges A 《Physical review letters》2004,93(19):192501
The electric dipole strength distribution in 44Ca has been measured up to 10 MeV in high resolution photon scattering experiments for the first time. The data obtained have been compared to earlier measurements on (40,48)Ca in order to view the evolution of the electric pygmy dipole resonance (PDR). Calculations that were performed within the framework of the microscopic extended theory of finite Fermi systems, which adds contributions of the quasiparticle-phonon coupling to random phase approximation calculations, give a qualitative agreement with the experimental data for all three isotopes. We have shown that it is necessary to include this coupling to describe the PDR. 相似文献