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871.
Rosa P Mézailles N Ricard L Mathey F Le Floch P Jean Y 《Angewandte Chemie (International ed. in English)》2001,40(7):1251-1253
872.
Bronowska A Chilmonczyk Z Leś A Edvardsen O Ostensen R Sylte I 《Journal of computer-aided molecular design》2001,15(11):1005-1023
In the present study experimentally determined ligand selectivity of three methylated buspirone analogues (denoted as MM2, MM5 and P55) towards 5-HT1A and 5-HT2A serotonin receptors was theoretically investigated on a molecular level. The relationships between the ligand structure and 5-HT1A and 5-HT2A receptor affinities were studied and the results were found to be in agreement with the available site-directed mutagenesis and binding affinity data. Molecular dynamics (MD) simulations of ligand-receptor complexes were performed for each investigated analogue, docked twice into the central cavity of 5-HT1A/5-HT2A, each time in a different orientation. Present results were compared with our previous theoretical results, obtained for buspirone and its non-methylated analogues. It was found that due to the presence of the methyl group in the piperazine ring the ligand position alters and the structure of the ligand-receptor complex is modified. Further, the positions of derivatives with pyrimidinyl aromatic moiety and quinolinyl moiety are significantly different at the 5-HT2A receptor. Thus, methylation of such derivatives alters the 3D structures of ligand-receptor complexes in different ways. The ligand-induced changes of the receptor structures were also analysed. The obtained results suggest, that helical domains of both receptors have different dynamical behaviour. Moreover, both location and topography of putative binding sites for buspirone analogues are different at 5-HT1A and 5-HT2A receptors. 相似文献
873.
G. Tabacaru B. Borderie P. Désesquelles M. Pârlog M. F. Rivet R. Bougault B. Bouriquet A. M. Buta E. Galichet B. Guiot P. Lautesse N. Le Neindre L. Manduci E. Rosato B. Tamain M. Vigilante J. P. Wieleczko 《The European Physical Journal A - Hadrons and Nuclei》2003,18(1):103-116
Enhanced production of events with almost equal-sized fragments is experimentally revealed by charge correlations in the multifragmentation of a finite nuclear system selected in 129Xe central collisions on
nat
Sn. The evolution of their weight with the incident energy: 32, 39, 45, 50 AMeV, is measured. Dynamical stochastic mean-field simulations performed at 32 AMeV, in which spinodal instabilities are responsible for multifragmentation, exhibit a similar enhancement of this kind of events. The above experimental observation evidences the spinodal decomposition of hot finite nuclear matter as the origin of multifragmentation in the Fermi energy regime.Received: 22 November 2002, Revised: 22 April 2003, Published online: 30 September 2003PACS:
25.70.Pq Multifragment emission and correlations - 24.60.Ky Fluctuation phenomenaG. Tabacaru: Present address: Cyclotron Institute, Texas A&M University, College station, Texas 77845, USA.N. Le Neindre: Permanent address: Institut de Physique Nucléaire, IN2P3-CNRS, F-91406 Orsay cedex, France. 相似文献
874.
E. Galichet F. Gulminelli D. C. R. Guinet M. F. Rivet J. F. Lecolley R. Bougault G. Auger B. Borderie B. Bouriquet A. Buta J. L. Charvet A. Chbihi J. Colin D. Cussol R. Dayras D. Durand J. D. Frankland B. Guiot S. Hudan P. Lautesse F. Lavaud N. Le Neindre O. Lopez L. Manduci J. Marie L. Nalpas J. Normand M. Pârlog P. Paw lowski E. Plagnol E. Rosato J. C. Steckmeyer B. Tamain A. Van Lauwe E. Vient C. Volant J. P. Wieleczko INDRA Collaboration 《The European Physical Journal A - Hadrons and Nuclei》2003,18(1):75-86
The transport properties of the 36Ar +58Ni system at
measured with the INDRA array, are studied within the BNV kinetic equation. A general protocol of comparison between the N-body experimental fragment information and the one-body distribution function is developed using global variables, with a special focus on charge density. This procedure avoids any definition of sources and any use of an afterburner in the simulation. We shall discuss the feasibility of such an approach and the distortions induced by the finite detection efficiency and the completeness requirements of the data selection. The sensitivity of the different global observables to the macroscopic parameters of the effective nuclear interaction will be studied in detail.Received: 21 January 2003, Published online: 5 August 2003PACS:
25.70.-z Low and intermediate energy heavy-ion reactions - 24.10.-i Nuclear reaction models and methodsN. Le Neindre: Permanent address: Institut de Physique Nuclaire, IN2P3-CNRS, F-91406 Orsay cedex, France. 相似文献
875.
David Blecher Christian Le Merdy 《Proceedings of the American Mathematical Society》2001,129(3):833-844
Let be a unital Banach algebra. We give a characterization of the left Banach -modules for which there exists a commutative unital -algebra , a linear isometry , and a contractive unital homomorphism such that for any . We then deduce a ``commutative" version of the Christensen-Effros-Sinclair characterization of operator bimodules. In the last section of the paper, we prove a -version of the latter characterization, which generalizes some previous work of Effros and Ruan.
876.
Labiche M Orr NA Marqués FM Angélique JC Axelsson L Benoit B Bergmann UC Borge MJ Catford WN Chappell SP Clarke NM Costa G Curtis N D'Arrigo A de Góes Brennand E Dorvaux O Fazio G Freer M Fulton BR Giardina G Grévy S Guillemaud-Mueller D Hanappe F Heusch B Jones KL Jonson B Le Brun C Leenhardt S Lewitowicz M Lopez MJ Markenroth K Mueller AC Nilsson T Ninane A Nyman G de Oliveira F Piqueras I Riisager K Saint Laurent MG Sarazin F Singer SM Sorlin O Stuttgé L 《Physical review letters》2001,86(4):600-603
The two-neutron halo nucleus (14)Be has been investigated in a kinematically complete measurement of the fragments ((12)Be and neutrons) produced in dissociation at 35 MeV/nucleon on C and Pb targets. Two-neutron removal cross sections, neutron angular distributions, and invariant mass spectra were measured, and the contributions from electromagnetic dissociation (EMD) were deduced. Comparison with three-body model calculations suggests that the halo wave function contains a large nu(2s(1/2))(2) admixture. The EMD invariant mass spectrum exhibited enhanced strength near threshold consistent with a nonresonant soft-dipole excitation. 相似文献
877.
Quantitative measurement of low propagation losses at 1.55 mum on planar photonic crystal waveguides
The Fabry-Perot resonance technique has been used to determine the propagation losses of planar photonic crystal (PC) waveguides. The structures are patterned into a GaInAsP confining layer on an InP substrate. Losses as low as 11 dB/mm have been measured on a guiding structure with three missing rows. The influence of the PC guide width and air-filling factor is demonstrated. 相似文献
878.
We have analyzed the constant loss contribution to the ac conductivity in the frequency range 10 Hz-1 MHz and temperatures down to 8 K, for two Li ionic conductors, one crystalline (Li(0.18)La(0.61)TiO(3)) and the other glassy (61SiO(2);35Li(2)O.3Al(2)O3.P(2)O(5)). As temperature is increased a crossover is observed from a nearly constant loss to a fractional power law frequency dependence of the ac conductivity. At any fixed frequency omega, this crossover occurs at a temperature T such that omega approximately nu(0)exp(-E(m)/k(B)T), where nu(0) is the attempt frequency and E(m) is identified with the barrier for Li+ ions to leave their wells. 相似文献
879.
We demonstrate that the interaction between atoms and a Gaussian beam changes the Lorentzian resonance into a so-called Rabi-Lorentzian resonance profile. The existence of such profiles is experimentally evidenced in a dark resonance situation for metastable (4) He, in the absence of any external perturbation. A topological mechanism is shown theoretically to account for the measured profiles. We observe a 3% systematic residual with respect to a pure Lorentzian profile, which could play a role in the search of high precision in the measurement of fundamental constants. 相似文献
880.
Critical-point phase separation in laser ablation of conductors 总被引:1,自引:0,他引:1
Vidal F Johnston TW Laville S Barthélemy O Chaker M Le Drogoff B Margot J Sabsabi M 《Physical review letters》2001,86(12):2573-2576
Laser ablation due to an ultrashort laser pulse on a massive aluminum target was investigated by means of a one-dimensional fluid code. Clear separation between the ablated matter and the unablated target is seen to occur through spinodal decomposition involving thermodynamic instabilities near the critical point of aluminum. The code also shows that the end of the ablation process is preceded by the ejection of droplets, which form about 15% of the total ejected mass. 相似文献