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91.
92.
Annabelle Scarpaci Clement Cabanetos Errol Blart Véronique Montembault Laurent Fontaine Vincent Rodriguez Fabrice Odobel 《Journal of polymer science. Part A, Polymer chemistry》2009,47(21):5652-5660
A one‐pot synthetic route based on copper‐catalyzed Huisgen reaction has been developed to functionalize a methacrylate propargylic polymer with azido‐substituted moieties. This procedure was used for the preparation of electro‐optic materials containing well‐known Disperse Red One (DR1) chromophores along with bulky adamantyl moieties (Adam). The postfunctionalization of the propargylic polymer was successfully achieved using different molar ratios of DR1/Adam. These novel polymers exhibit high glass transition temperature owing to the rigid structure of adamantyl units. Moreover, the second harmonic generation measurements demonstrated the effectiveness of adamantyl groups to act as insulating shield limiting thus the electrostatic interactions between chromophores. Indeed, higher optimal chromophore concentration (50 mol %) than in conventional DR1‐containing polymers (30 mol %) allowed us to increase the d33 coefficient up to 92 pm/V. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5652–5660, 2009 相似文献
93.
M. Abdel-Bary S. Abdel-Samad R. Bilger K.-Th. Brinkmann H. Clement S. Dshemuchadse E. Dorochkevitch H. Dutz W. Eyrich A. Erhardt D. Filges A. Filippi H. Freiesleben M. Fritsch R. Geyer A. Gillitzer D. Hesselbarth B. Jakob L. Karsch K. Kilian H. Koch J. Kreß E. Kuhlmann S. Marcello S. Marwinski S. Mauro W. Meyer P. Michel K. Möller H. P. Morsch L. Naumann N. Paul M. Richter E. Roderburg M. Rogge A. Schamlott M. Schmitz P. Schönmeier M. Schulte-Wissermann W. Schroeder T. Sefzick F. Stinzing G.Y. Sun G.J. Wagner M. Wagner A. Wilms P. Wintz S. Wirth P. Zupranski 《The European Physical Journal A - Hadrons and Nuclei》2003,16(1):127-137
The reaction pp → ppη was measured at excess energies of 15 and 41 MeV at an external target of the Jülich Cooler Synchrotron COSY with the time-of-flight
spectrometer. About 25000 events were measured for the excess energy of 15 MeV and about 8000 for 41 MeV. Both protons of
the process ppη were detected with an acceptance of nearly 100% and the η was reconstructed by the missing-mass technique. For both excess
energies the angular distributions are found to be nearly isotropic. In the invariant-mass distributions strong deviations
from the pure phase space distributions are seen.
Received: 24 May 2002 / Accepted: 20 September 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: e.roderburg@fz-juelich.de
Communicated by M. Gar?on 相似文献
94.
Atmospheric gas concentrations were measured at 1 s intervals in the upper troposphere during a flight through and near the anvil of a storm. The observed very high correlations between the concentrations of CO and CH4 are interpreted as arising from the mixing of two distinct air masses with differing concentrations of each species, and is due to the nearly identical diffusivities of CO and CH4 in air. We find that the correlations depend on the period over which each concentration measurement was made. Correlations in measurements made over short periods decay with time, while correlations over larger scales remain high. We interpret this using a simple mixing model. 相似文献
95.
Matrix elements of multipole operators, defined separately for neutrons and protons, are related to spin-dependent sums of spectroscopic factors. A clarification of their relation to the matrix elements of single-particle operators enables the overlap representation to be formally extended to a stripping form for J ≠ 0 operators. Multipole moments obtained from transfer data are found to be dominated by the quadrupole moments when the final nucleus is odd-odd.A previously found (2J + 1) rule for spectroscopic sums, which arises when the odd-J multipole moments vanish, is shown to lead to approximate sum rules which apply separately to stripping and pickup data. The sum rules are generally well satisfied for transfers leading to odd-odd nuclei in the s-d shell. 相似文献
96.
Excitation curves for the elastic and the inelastic scattering of polarized protons on the target nuclei 138Ba, 140Ce, 142Nd and 144Sm have been measured in the energy region of prominent isobaric analog resonances. A detailed analysis of the data is presented. Definite Jπ assignments are given for a number of parent analog states. Spectroscopic factors and amplitudes for configurations with the core in the ground state or in the 21+ excited state are derived from the elastic and inelastic proton decay amplitudes. They show consistency with sum rules including orthogonality conditions. Different methods for the-calculation of single particle decay widths have been applied. The qualitative agreement with present unified model calculations is remarkable; an overestimattion of the weak coupling structure, however, becomes apparent. 相似文献
97.
Total neutron cross sections, using a continuous-energy source of neutrons, were measured for hydrogen and deuterium. The neutron energy range covered was from less than 1 MeV, to about 30 MeV. No structure is observed for either isotope. The precision of the cross-section magnitudes appears to be within 1 % over much of the measured energy interval. 相似文献
98.
Let G be an additive group and C
k
be the additive group of the ring Z
k
of residues modulo k. If there exist a (G, k, ) difference family and a (G, k, ) perfect Mendelsohn difference family, then there also exists a
difference family. If the (G, k, ) difference family and the (G, k, ) perfect Mendelsohn difference family are further compatible, then the resultant
difference family is elementary resolvable. By first constructing several series of perfect Mendelsohn difference families, many
difference families and elementary resolvable
difference families are thus obtained. 相似文献
99.
Loh BG Hyun S Ro PI Kleinstreuer C 《The Journal of the Acoustical Society of America》2002,111(2):875-883
Acoustic streaming induced by ultrasonic flexural vibrations and the associated convection enhancement are investigated. Acoustic streaming pattern, streaming velocity, and associated heat transfer characteristics are experimentally observed. Moreover, analytical analysis based on Nyborg's formulation is performed along with computational fluid dynamics (CFD) simulation using a numerical solver CFX 4.3. Two distinctive acoustic streaming patterns in half-wavelength of the flexural vibrations are observed, which agree well with the theory. However, acoustic streaming velocities obtained from CFD simulation, based on the incompressible flow assumption, exceed the theoretically estimated velocity by a factor ranging from 10 to 100, depending upon the location along the beam. Both CFD simulation and analytical analysis reveal that the acoustic streaming velocity is proportional to the square of the vibration amplitude and the wavelength of the vibrating beam that decreases with the excitation frequency. It is observed that the streaming velocity decreases with the excitation frequency. Also, with an open-ended channel, a substantial increase in streaming velocity is observed from CFD simulations. Using acoustic streaming, a temperature drop of 40 degrees C with a vibration amplitude of 25 microm at 28.4 kHz is experimentally achieved. 相似文献
100.
Let = (f, g):(Cn+ 1,0) (C2, 0) be a pair of holomorphic germswith no blowing up in codimension 0. (Two examples are the following: defines an isolated complete intersection singularity; g =lN where is a generic linear form with respect to f and N>0.) We study how the Milnor fibrations of the germs (:ß)= g-ß f are related to each other when (:ß)varies in P1. More precisely, we construct isotopic subfibrationsor subfibres of the Milnor fibrations of any two such germs.The proofs are based on the precise study of the subdiscs ofcomplex lines meeting a fixed complex plane curve germ transversally,generalizing Lê's work on the Cerf diagram. 2000 MathematicalSubject Classification: 32S55, 32S15, 32S30. 相似文献