In this report, we study the ordering of C60, Sc3N@C80, and Dy2ScN@C80 molecules on different metallic and dielectric surfaces such as Ag(100), Au(111), and MgO(100). By using DFT techniques, we can ...classify different types of cage‐to‐surface arrangements and their relative energies. Using a proposed homogenous sampling of the conformational space for the M3N cluster, we determine a potential energy map that is capable of providing a structural distribution for a given energy window. We find that Coulomb interaction is a dominant force that governs the system's stability and order. However, a deep analysis of the charge density rearrangements reveals that even though the integral charges may be considered as a qualitative control parameter, it fails to provide quantitative data due to the importance of spatial characteristics of charge densities.
This work outlines a computational strategy for conformational analysis of cluster fullerenes in proximity to metal and dielectric surfaces.
We present a search for f{sub J}(2220) production in radiative J/{psi} {yields} {gamma}f{sub J}(2220) decays using 460 fb{sup -1} of data collected with the BABAR detector at the SLAC PEP-II e{sup ...+}e{sup -} collider. The f{sub J}(2220) is searched for in the decays to K{sup +}K{sup -} and K{sub S}{sup 0}K{sub S}{sup 0}. No evidence of this resonance is observed, and 90% confidence level upper limits on the product of the branching fractions for J/{psi} {yields} {gamma}f{sub J}(2220) and f{sub J}(2220) {yields} K{sup +}K{sup -}(K{sub S}{sup 0}K{sub S}{sup 0}) as a function of spin and helicity are set at the level of 10{sup -5}, below the central values reported by the Mark III experiment.
This article examines the issue of forecasting the time series of server systems and suggests applying the triple exponential smoothing model to solve this problem. It presents a mathematical ...formulation of the problem and describes the specifics of forecasting the time series of server systems. After this the article gives a comparative analysis of the autoregressive, neural network and exponential smoothing models in terms of their application to this problem. It argues that the triple exponential smoothing model (Holt-Winters method) offers a number of advantages when modelling the time series of server systems. It then provides experimental research to evaluate the accuracy of the Holt-Winters method with respect to the indicated time series. The research shows that the triple exponential smoothing model exhibits high results and can be applied to the solution of practical problems.
•High quality single crystal of Co3(BO3)2 was grown by the flux method.•The low temperature XRD experiments were performed and no evidences of the magneto-structural phase transition were ...observed.•The lattice dynamics of Co3(BO3)2 were investigated by IR and Raman spectroscopies, and supplemented by the DFT calculations.•Infrared- and Raman-active phonons were registered and assigned.
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Transition metal oxyborates M3(BO3)2 (M = Mn, Co, Ni) belong to a group of materials with the kotoite structure and many of them demonstrate complex magnetic behavior as a result of competing interactions between magnetic ions in nonequivalent crystallographic positions. In this paper, we report results of the detailed infrared and Raman spectroscopic studies of a Co3(BO3)2 single crystal. Most of the phonons are observed and identified. Unusually large phonon shifts, in comparison to isostructural compound Ni3(BO3)2, were registered in the low- and mid-infrared frequency range (100–700 cm−1) of the spectra. The experimental findings are supported by the ab initio simulations of the lattice dynamics, which allow us to propose the normal-mode assignments. We argue that the large phonon shift between cobalt and nickel compounds are associated with changes of force constants induced by the changes of M–O bond lengths within the two types of octahedral MO6 groups. In addition to the first-order Raman scattering, intense second-order Raman scattering was detected due to the resonant enhancement regime. Furthermore, we performed the single crystal XRD experiments which did not show any detected evidences of magneto-structural phase transition previously observed in Ni3(BO3)2.
The structural study of plant viruses is of great importance to reduce the damage caused by these agricultural pathogens and to support their biotechnological applications. Nowadays, X-ray ...crystallography, NMR spectroscopy and cryo-electron microscopy are well accepted methods to obtain the 3D protein structure with the best resolution. However, for large and complex supramolecular structures such as plant viruses, especially flexible filamentous ones, there are a number of technical limitations to resolving their native structure in solution. In addition, they do not allow us to obtain structural information about dynamics and interactions with physiological partners. For these purposes, small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM) are well established. In this review, we have outlined the main principles of these two methods and demonstrated their advantages for structural studies of plant viruses of different shapes with relatively high spatial resolution. In addition, we have demonstrated the ability of AFM to obtain information on the mechanical properties of the virus particles that are inaccessible to other experimental techniques. We believe that these under-appreciated approaches, especially when used in combination, are valuable tools for studying a wide variety of helical plant viruses, many of which cannot be resolved by classical structural methods.
Observation of the Decay B⁻→Ds()+K⁻l⁻ν⁻⁻l Prencipe, E.; Hooberman, B.; Kolomensky, Yu. G. ...
Physical review letters,
07/2011, Letnik:
107, Številka:
4
Journal Article
Recenzirano
We report the observation of the decay B⁻→Ds(*)+K⁻l⁻ν¯l based on 342fb⁻¹ of data collected at the Υ(4S) resonance with the BABAR detector at the PEP-II e⁺e⁻ storage rings at SLAC. A simultaneous fit ...to three D+s decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay B⁻→Ds(*)+K⁻l⁻ν¯l with a significance greater than 5 standard deviations (including systematic uncertainties) and measure its branching fraction to be B(B⁻→Ds(*)+K⁻l⁻ν¯l)=6.13+1.04-1.03(stat)±0.43(syst)±0.51(B(Ds))×10⁻⁴, where the last error reflects the limited knowledge of the Ds branching fractions.
Abstract
Unified model of the automated information data system (AIS) at the commercial enterprises (UMAIS CE) as a protected AIS for the provision of the commercial activity of the enterprises with ...the common structure and configuration of equipment is examined in the article. Information integrity control (IIC) is an integral part of this model, and its functioning has an impact on the contingent profit of the commercial enterprise considered in the frameworks of UMAIS CE. Mathematical model of IIC UMAIS CE presented within this context, just as a number of computing experiment that allow determining of a strategy of the effective usage of IIC UMAIS CE and specified ways for increase of the contingent profit at the commercial enterprise.
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