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361.
N. P. Andreeva V. Bradnova S. Vokal A. Vokalova A. Sh. Gaitinov S. G. Gerasimov L. A. Goncharova V. A. Dronov P. I. Zarubin I. G. Zarubina A. D. Kovalenko A. Kravchakova V. G. Larionova O. V. Levitskaya F. G. Lepekhin A. I. Malakhov A. A. Moiseenko G. I. Orlova N. G. Peresadko N. G. Polukhina P. A. Rukoyatkin V. V. Rusakova N. A. Salmanova V. R. Sarkisyan B. B. Simonov E. Stan R. Stanoeva M. M. Chernyavsky M. Haiduc S. P. Kharlamov I. Tsakov T. V. Schedrina 《Physics of Atomic Nuclei》2005,68(3):455-465
Experimental observations of the multifragmentation of relativistic light nuclei by means of emulsions are surveyed. Events that belong to the type of “white stars” and in which the dissociation of relativistic nuclei is not accompanied by the production of mesons and target-nucleus fragments are considered. An almost complete suppression of the binary splitting of nuclei to fragments of charge in excess of two, Z > 2, is a feature peculiar to charge topology in the dissociation of Ne, Mg, Si, and S nuclei. An increase in the degree of nuclear fragmentation manifests itself in the growth of the multiplicity of singly and doubly charged fragments (Z = 1, 2) as the charge of the unexcited fragmenting-nucleus part (which is the main part) decreases. Features of the production of systems formed by extremely light nuclei α, d, and t are studied in the dissociation of the stable isotopes of Li, Be, B, C, N, and O to charged fragments. Manifestations of 3He clustering can be observed in “white stars” in the dissociation of neutron-deficient isotopes of Be, B, C, and N. 相似文献
362.
We have theoretically investigated the electronic properties and nonlinear optical rectification spectra of GaAs/AlGaAs anisotropic quantum ring, modelled by an outer ellipsis and an inner circle, in connection to the presence of a donor off-centre impurity, structural distortions and in-plane electric field. The one-electron energy spectrum and wave functions are found using the adiabatic approximation and the finite element method within the effective-mass model. The energy spectrum of concentric ring reveals an anomalous oscillatory behaviour in the region of relatively small values of the electric field (< 12?kV/cm) followed by linear Stark effect at higher field values. We showed that this unusual behaviour is strongly affected by the ratio of the outer/inner ring radii, the displacement of the inner circle (eccentricity) along the x or y axis and the impurity presence. The related nonlinear optical rectification spectra present maxima whose positions mirror this oscillatory behaviour and consequently can be used as an excellent tool to distinguish the presence of an impurity or the direction of the eccentricity. 相似文献
363.
We provide several inequalities for the ? q (𝒫)-norm of the Wick product of random variables. These estimates are based on a Jensen's type inequality for the Wick multiplication, which we derive via a positivity argument. As an application we study a certain type of anticipating stochastic differential equation whose solution is shown to be an element of ? q (𝒫) for some q ≥ 1. 相似文献
364.
The cleavage of a set of phosphate mono-, di-, and triesters having a Cu(II)-complexed 2-phenanthrolyl group at the ortho-position of a departing phenoxide was studied in water and ethanol. Experimentally observed pH/rate profiles, solvent deuterium kinetic isotope effects, and activation parameters are compared with those obtained in methanol. The pH/rate profile in each solvent exhibits an extended plateau due to solvent attack on forms designated as [Cu(II):1b/c](0) for the monoester, [Cu(II):2b](+), for the diester, and [Cu(II):3a](2+) for the triester. The solvent dkie values (k(H)/k(D)) for the three complexes are 0.91, 0.95, and 0.83 for decomposition of [Cu(II):1b/c](0) in water (W), methanol (M), and ethanol (E), 1.22, 1.09, and 1.29 for [Cu(II):2b](+) in W, M, and E, and 1.94, 2.2, and 1.96 for [Cu(II):3a](2+) in W, M, and E. Near unit, or slightly inverse values for the monoester are taken as evidence for little involvement of solvent in a highly dissociative TS for P-OAr cleavage, with slightly higher solvent dkie values for the diester signifying the onset of some solvent participation in assisting the nucleophilic displacement. The larger primary dkie for the triester gives evidence for a solvent-assisted delivery of ROH in the cleavage through a more associative mechanism. Activation parameters for each substrate in the solvents are compared, indicating that the transition from methanol to ethanol for each substrate involves a near cancellation of the ΔΔH(?) and -TΔΔS(?) values (25 °C) so that the respective rates in both solvents are very similar. The transition from alcohol to water produces variable effects, with ΔΔH(?) and -TΔΔS(?) values canceling for cleavage of the triester and being additive for the mono and diester, explaining their 100-500 rate reduction in passing from methanol to water. The rate enhancing effects of the Cu(II)-promoted leaving group assistance in all three solvents are substantial and estimated at 10(12)-10(15) for the monoester, 10(12)-10(14) for the diester, and 10(5) for the triester relative to their background reactions. 相似文献
365.
Mechatronics consists in integration of three fields in engineering: mechanics, electronics and information technology. The paradigm of mechatronics is the integration concept, being the first step in the design of complex mechatronic systems. The need for an integrated approach to the design of complex engineering system involving electronic engineering, mechanical engineering and computing has led to the growth of the concept of mechatronics. The paper presents details regarding the integration process for the kinematic axis in mechatronic. The example of the positioning system based on dc motor and screw–nut transmission is analysed. This actuator is further used for driving a 2 DOF PRRRP parallel robot. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
366.
P. A. Holstein M. Casanova A. Casner C. Cherfils E. Dattolo L. Disdier D. Galmiche J. Giorla M. Houry J. P. Jadaud S. Laffite S. Liberatore P. Loiseau L. Lours L. Masse M. C. Monteil O. Morice M. Naudy F. Philippe F. Poggi F. Renaud G. Riazuelo Y. Saillard P. Seytor M. Vandenboomgaerde F. Wagon 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):239-247
This article sums up the theoretical and experimental studies about
ignition. Three experiments are salient this year on the Omega laser in
collaboration with DOE laboratories (1) 3 cones of beams allow to mimic the
LMJ configuration and to get symmetry measurements. (2) We measured
perturbations due to hydro-instability in CHGe planar samples with face-on
and side-on radiographs. (3) We improved our nuclear diagnostics,
particularly the neutron image system tested on direct drive implosions. As far as LMJ target design is concerned, we defined
a preliminary domain
corresponding to the possible operation at 2ω. At 3ω we studied the low mode
instability effects on the DT deformation (due to the laser or to the
target) and on the yield. The stability is clearly improved with graded
doped CH for our nominal capsule L1215. 相似文献
367.
The title sesquiterpenes are synthesized in one step from the common intermediate 4-(6-methyl-5-hepten-2-yl)-2-cyclohexen-1-one, which is prepared using a one-pot tandem arylation-multistep reduction-hydrolysis sequence. 相似文献
368.
S. Staněk 《Archiv der Mathematik》2000,74(6):452-466
A class of nonlinear functional boundary conditions for the system of functional differential equations x"(t)=(F(x,y))(t)x'(t)=(F(x,y))(t), y"(t)=(H(x,y))(t)y'(t)=(H(x,y))(t) is introduced. Here F, H:C1([a,b]) ×C1([a,b]) ? L1([a,b])F,\,H:C^1([a,b]) \times C^1([a,b]) \rightarrow L_1([a,b]) are nonlinear continuous operators. Sufficient conditions for the existence of at least four solutions are given. Results are proved by the Bihari lemma, the Leray-Schauder degree theory and the Borsuk theorem. 相似文献
369.
JPC – Journal of Planar Chromatography – Modern TLC - A high-performance thin-layer chromatography (HPTLC) method has been established for the analysis of α-phellandrene and... 相似文献
370.
The development and optimization of on-line microdistillation for free and total sulfite (S(IV)) in grape juice and wine is reported. The microstill used both heat and an air stream to separate sulfur dioxide from the wine samples; the distillation product was captured in a peroxide solution, and converted to sulfuric acid, mirroring accepted industry practice. Measured from 1 to 300 mg L−1 as SO2 by conductance, sample throughputs of 60 h−1 for free and 20 h−1 for total sulfite were achieved. Data for bound S(IV) emphasises the slow kinetics of release reactions in some wines. The microstill method is more efficient for total sulfite than the accepted manual technique. Good correlation was found between the microstill and manual methods under specified control conditions. 相似文献