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991.
The distribution of property is established through various mechanisms. In this paper we study the acreage distribution of land plots owned by natural persons in the Zlín Region of the Czech Republic. We show that the data are explained in terms of a simple model in which the inheritance and market behavior are combined. 相似文献
992.
Nicolas Delerue Sudhir Dixit Fred Gannaway David Howell Myriam Qurshi Grahame Blair Stewart Boogert Gary Boorman Chafik Driouichi Lawrence Deacon Alexander Aryshev Pavel Karataev Nobuhiro Terunuma Junji Urakawa Axel Brachmann Joe Frisch Marc Ross 《Pramana》2007,69(6):1147-1150
A new laser-wire has been installed in the extraction line of the ATF at KEK. It aims at demonstrating that laser-wires can
be used to measure micrometre scale beam size. In parallel, studies have been made to specify a laser suitable for the ILC
laser-wires.
相似文献
993.
Rulísek L Sebek P Havlas Z Hrabal R Capek P Svatos A 《The Journal of organic chemistry》2005,70(16):6295-6302
The stereoselectivity of the reaction of furan (1) with maleic anhydride (2) and maleimide (3) was studied experimentally and theoretically. Although the two reactions are highly similar with regard to their preference for endo and exo steroisomers, notable differences were experimentally observed and explained on the basis of calculated reaction-free energies and transition-state barriers. The experimental values of rate constants (k(1+2endo) = (1.75 +/- 0.48) x 10(-5); mol(-1) l s(-1); k(1+2exo) = (3.10 +/- 0.55) x 10(-5); mol(-1) l s(-1); k(1+3endo) = (1.93 +/- 0.082) x 10(-5); mol(-1) l s(-1), k(1+3exo) = (1.38 +/- 0.055) x 10(-5); mol(-1) l s(-1) all at 300 K) and the observed reaction course clearly confirm that neither of these reactions are prototypical examples of Diels-Alder [4 + 2] cycloadditions, whose dominant preference is for endo isomers. However, only by comparing their energetics-calculated at the CCSD(T) level of theory-with the analogous reactions involving cyclopentadiene (8) as a diene can these observations be understood. The low thermodynamic stability of furan [4 + 2] adducts opens retro-Diels-Alder reaction channels and overrules the very small kinetic preference (calculated and measured here) of initial formation for endo stereoisomers. On a macroscopic scale "an irregular"-thermodynamically more stable-exo stereoisomer was consequently observed as a dominant species. 相似文献
994.
Surface Brillouin spectroscopy (SBS) has been widely used for elastic property characterization of thin films. For films thicker than 500 nm, however, the wavelength of surface acoustic wave in the frequency range available for SBS is smaller than film thickness, and the SBS measures only the Rayleigh wave of the film. The laser-SAW technique, on the other hand, measures only the low-frequency portion of the surface acoustic wave dispersion and can estimate only one elastic modulus of the film (typically Young's modulus). In this work, we have combined the two methods to determine both Young's modulus and Poisson's ratio of a diamond-like carbon (DLC) film. It was found that reasonable estimates can be obtained for the longitudinal wave velocity, shear wave velocity, and Young's modulus of the film. The Poisson's ratio, however, still has a relatively large measurement error. 相似文献
995.
The 2S electron bubble placed in liquid helium has been previously believed to be spherical. We show that the 2S bubble is morphologically unstable at pressures above -1.23 bars. The 2S state being known to be radially unstable at pressures below -1.33 bars, the result leaves only a very narrow pressure range in which it can be found in a spherical configuration. Our stability analysis indicates that the 2S bubble is unstable against perturbations proportional to any of the third spherical harmonics Y(3m). Our numerical simulations show that there exist nonspherical stable configurations, such as the ones Maris and Konstantinov predicted for the 1P, 1D, and 2P electron bubbles and confirmed experimentally for the 1P. We believe that the 2S bubbles can also be produced and that our prediction will yield itself to experimental verification. 相似文献
996.
It is believed that a disordered one-dimensional (1D) wire with coherent electronic conduction is an insulator with the mean resistance approximately equal e(2L/xi) and resistance dispersion Delta(rho) approximately equal e(L/xi), where L is the wire length and xi is the electron localization length. Here we show that this 1D insulator undergoes at full coherence the crossover to a 1D "metal," caused by thermal smearing and resonant tunneling. As a result, Delta(rho) is smaller than unity and tends to be L/xi independent, while grows with L/xi first nearly linearly and then polynomially, manifesting the so-called medium localization. 相似文献
997.
Vondrásek J Bendová L Klusák V Hobza P 《Journal of the American Chemical Society》2005,127(8):2615-2619
The formation of a hydrophobic core of globular proteins is believed to be the consequence of exterior hydrophobic forces of entropic nature. This, together with the low occurrence of hydrogen bonds in the protein core, leads to the opinion that the energy contribution of core formation to protein folding and stability is negligible. We show that stabilization inside the hydrophobic core of a small protein, rubredoxin, determined by means of high-level correlated ab initio calculations (complete basis set limit of MP2 stabilization energy + CCSD(T) correction term), amounted to approximately 50 kcal/mol. These results clearly demonstrate strong attraction inside a hydrophobic core. This finding may lead to substantial changes in the current view of protein folding. We also point out the inability of the DFT/B3LYP method to describe a strong attraction between studied amino acids. 相似文献
998.
We prove a product formula which involves the unitary group generated by a semibounded self-adjoint operator and an orthogonal projection P on a separable Hilbert space
with the convergence in
It gives a partial answer to the question about existence of the limit which describes quantum Zeno dynamics in the subspace Ran P. The convergence in
is demonstrated in the case of a finite-dimensional P. The main result is illustrated in the example where the projection corresponds to a domain in
and the unitary group is the free Schrödinger evolution.submitted 21/06/04, accepted 12/10/04 相似文献
999.
Liliana Pavel 《Comptes Rendus Mathematique》2005,341(8):475-480
Let K be a hypergroup with Haar measure. We relate Reiter's condition to positive definite measures and associated representations, induced representations from a subgroup of K and convolution operators on . To cite this article: L. Pavel, C. R. Acad. Sci. Paris, Ser. I 341 (2005). 相似文献
1000.
Schmid C Trojek P Bourennane M Kurtsiefer C Zukowski M Weinfurter H 《Physical review letters》2005,95(23):230505
We present a simple and practical protocol for the solution of a secure multiparty communication task, the secret sharing, and its proof-of-principle experimental realization. In this protocol, a secret is split among several parties in a way that its reconstruction requires the collaboration of the participating parties. In our scheme the parties solve the problem by sequential transformations on a single qubit. In contrast with recently proposed schemes involving multiparticle Greenberger-Horne-Zeilinger states, the approach demonstrated here is much easier to realize and scalable in practical applications. 相似文献