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1.
András Sütő 《Journal of statistical physics》2003,112(1-2):375-396
We study condensation of trapped bosons in the limit when the number of particles tends to infinity. For the noninteracting gas we prove that there is no phase transition in any dimension, but in any dimension, at any temperature the system is 100% condensated into the one-particle ground state. In the case of an interacting gas we show that for a family of suitably scaled pair interactions, the Gross–Pitaevskii scaling included, a less-than-100% condensation into a single-particle eigenstate, which may depend on the interaction strength, persists at all temperatures. 相似文献
2.
In this paper the distribution of the zeros of the error function for bestL
1-approximation by rational functions fromR
n,m
is considered. It is shown that the maximal distance between such zeros isO(1/(n–m)), ifn > m.Communicated by Edward B. Saff. 相似文献
3.
Summary Bhattacharya, Chernoff and Yang (1983) proposed a nonparametric estimate for the slope of a regression lineY =
o
X + V subjected to the truncationYy
0. The estimate corresponds to the zero-crossing of a random functionS
n
(). In this paper an estimate for the asymptotic variance of the estimate of the slope is proposed and the rate of convergence is given. The proofs rest heavily on the local behavior ofS
n
() in the neighborhood of the true value o. 相似文献
4.
5.
Szantai E Ronai Z Szilagyi A Sasvari-Szekely M Guttman A 《Journal of chromatography. A》2005,1079(1-2):41-49
The investigation of the genetic background and phenotype structures of complex diseases, such as cardiovascular or psychiatric disorders and tumors, is one of the most scrutinized fields of the post genomic era. Besides the multiplex analysis of genetic markers and polymorphisms throughout the whole genome, more and more attention is focused on the interaction between the etiological factors of these traits. Haplotype determination, rather than multiplex genotyping seems to be one of the first building blocks of this endeavor. This review focuses on the importance and theoretical background of haplotyping, and summarizes the recent examples of novel and emerging haplotyping techniques by capillary gel electrophoresis based DNA fragment analysis, a powerful tool for the examination of the inheritance of complex traits. 相似文献
6.
Gáti T Simon A Tóth G Magiera D Moeller S Duddeck H 《Magnetic resonance in chemistry : MRC》2004,42(7):600-604
Adducts of four phosphine chalcogenides with the chiral dirhodium complex ([Rh-Rh]) were investigated by variable-temperature 1H and 31P NMR spectroscopy in order to compare their properties as axial ligands. Whereas the selenide (1) and the sulfide (2) are strong ligands with electrostatic attraction and, in addition, a significant orbital (HOMO-LUMO) interaction, the phosphine oxide compounds (P=O) bind primarily via electrostatic attraction and are relatively weak donors. Moreover, the overall bond strength in these adducts depends on steric congestion around the P=O group. 相似文献
7.
Andersson I Gorzsás A Pettersson L 《Dalton transactions (Cambridge, England : 2003)》2004,(3):421-428
A detailed study of the quaternary aqueous H+/H2VO4-/H2O2/picolinate (Pi-) system has been performed at 25 degrees C in 0.150 M Na(Cl) medium using quantitative 51 V NMR (500 MHz) and potentiometric data (glass electrode). In the ternary H+/H2VO4-/Pi- system, six complexes have been found in the pH region 1-10. In the quaternary H+/H2VO4-/H2O2/Pi- system, eight additional complexes have been found. Generally, equilibria are fast in both systems. The rate of peroxide decomposition depends on the species in solution. Chemical shifts, compositions and formation constants for the species are given. Equilibrium conditions and the fit of the model to the experimental data are illustrated in distribution diagrams. Possible formation of mixed ligand species with imidazole, lactic acid and citric acid have been investigated and ruled out under the same experimental conditions. Structural proposals are given, based on 1)C NMR data and available crystal structures. 相似文献
8.
András Sütő 《Communications in Mathematical Physics》1987,111(3):409-415
The spectrum (H) of the tight binding Fibonacci Hamiltonian (H
mn=
m,n+1+
m+1,n
+
m,n
v(n),v(n)=
((n–1)), 1/ is the golden number) is shown to coincide with the dynamical spectrum, the set on which an infinite subsequence of traces of transfer matrices is bounded. The point spectrum is absent for any , and (H) is a Cantor set for 4. Combining this with Casdagli's earlier result, one finds that the spectrum is singular continuous for 16.On leave from the Central Research Institute for Physics, Budapest, Hungary 相似文献
9.
Briggs CR Allen MJ O'Hagan D Tozer DJ Slawin AM Goeta AE Howard JA 《Organic & biomolecular chemistry》2004,2(5):732-740
The energies of the gauche and anti conformers of 2-fluoroethylamine, 2-fluoroethanol and their protonated analogues are calculated using density functional theory. Unlike the non protonated systems, the protonated systems show a strong gauche effect where the C-F and the C-(+)NH(3) or C-F and C-(+)OH(2) bonds are gauche rather than anti to each other. Single crystal X-ray diffraction studies of 2-fluoroethylammonium compounds identify the same conformational preference. 相似文献
10.
Summary The chiral discrimination of phenoxypropionic acid herbicides by reversed-phase chromatography on a teicoplanin phase has been re-examined using the perturbation method to calculate the solute distribution isotherms. The effects of both temperature and the methanol (organic modifier) content of the mobile phase on the chiral discrimination mechanism were well described by the bi-Langmuir model. The method confirmed a change in the mechanism of enantiomer retention at a critical temperature, T*, and showed that the mechanism was independent of (i) herbicide molecular structure, i.e. the position of the chloro group on the phenol ring, and (ii) the absolute configuration of the carbon atom. Enantioselectivity was enhanced by increasing the mobile phase methanol content. Use of this approach also revealed that secondary sites on the teicoplanin surface were involved in the processes determining both retention and selectivity. It was clearly demonstrated that these secondary sites of low affinity were not affected by the temperature change and were not involved in the chiral recognition mechanism. 相似文献