Size Effect in Ethylene Oxidation over Silver Nanoparticles Supported on HOPG

A preparation procedure for a model catalyst – stable silver nanoparticles with a narrow size distribution supported on highly oriented pyrolytic graphite (Ag/HOPG) – is presented. This procedure is carried out under ultra high vacuum conditions and consists of three stages: 1 – surface defect formation by soft Ar+-treatment; 2 – silver deposition; 3 – defect annealing by heating at T = 300 °C. The analysis of oxygen forms on a silver surface was carried out by in-situ X-ray photoelectron spectroscopy (XPS). The simultaneous presence of two oxygen species (electrophilic and nucleophilic) on the silver surface was found to be necessary for high activity of the model catalyst in ethylene epoxidation. An alternative explanation of the size effect in ethylene oxidation has been suggested: size dependence of the reaction rate may result from the existence of a ring-shaped zone at the edge of silver particles in which the surface concentration of nucleophilic oxygen is not uniform. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3514

Energy levels in muonic helium

The energy spectrum of bound states and hyperfine structure of muonic helium is calculated on the basis of stochastic variational method. The basis wave functions of the muonic molecule are taken in the Gaussian form. The matrix elements of the Hamiltonian are calculated analytically. For numerical calculation, a computer code is written in the MATLAB system. As a result, the numerical values of bound state energies and hyperfine structure for muonic helium are obtained.The work is supported by the RSF (Grant 18-12-00128)

On the Schr\"odinger Equation for the Supersymmetric FRW Model

We consider a time-dependent Schr\"odinger equation for the Friedmann-Robertson-Walker (FRW) model. We show that for this purpose it is possible to include an additional action invariant under reparametrization of time. The last one does not change the equations of motion for the minisuperspace model, but changes only the constraint. The same procedure is applied to the supersymmetric case.Comment: 15 pages. Revtex. Accepted for publication in Phys. Lett.

Color mixing models for smart lighting systems based on RGBW and WW LEDs

Color mixing models to obtain white light with a predetermined values of correlated color temperature and brightness are presented. One model describes mathematical algorithm for combination of spectra for WW LEDs lighting systems, and other one for systems based on RGBW LEDs. Results of testing of created sample of LED light source for indoor lighting (“Amstrong” type) with implemention of presented color mixing models are shown

The theory and direct observation of controlled (suppressed) spontaneous nuclear gamma-decay

The theory of controlling and changing the spontaneous nuclear gamma-decay is discussed. The phenomenon of nuclear decay controlling is a result of the interaction of radioactive nuclei with zero-energy electromagnetic modes, which in turn interact with distant controlling and controlled screen. It was shown that the decay parameters greatly depend on the sign and magnitude of the radiation shift (radiation correction) of the resonance level position. In the experiment we have discovered the change (increase) of radiative life-time of excited nucleus Co⁵⁷ (Fe⁵⁷*) (in relation to resonant Mossbauer gamma-channel of decay) by 10-40% and total life-time (including non-controlled non-Mossbauer radiation and non-controlled electron conversion channel of nucleus decay) by 1%

Accounting for International War: The State of the Discipline

In studies of war it is important to observe that the processes leading to so frequent an event as conflict are not necessarily those that lead to so infrequent an event as war. Also, many models fail to recognize that a phenomenon irregularly distributed in time and space, such as war, cannot be explained on the basis of relatively invariant phenomena. Much research on periodicity in the occurrence of war has yielded little result, suggesting that the direction should now be to focus on such variables as diffusion and contagion. Structural variables, such as bipolarity, show contradictory results with some clear inter-century differences. Bipolarity, some results suggest, might have different effects on different social entities. A considerable number of studies analysing dyadic variables show a clear connection between equal capabilities among contending nations and escalation of conflict into war. Finally, research into national attributes often points to strength and geographical location as important variables. In general, the article concludes, there is room for modest optimism, as research into the question of war is no longer moving in non-cumulative circles. Systematic research is producing results and there is even a discernible tendency of convergence, in spite of a great diversity in theoretical orientations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69148/2/10.1177_002234338101800101.pd

Measurement of the mass difference between top quark and antiquark in pp collisions at root s=8 TeV

Peer reviewe

Measurement of the Z boson differential cross section in transverse momentum and rapidity in proton-proton collisions at 8 TeV

We present a measurement of the Z boson differential cross section in rapidity and transverse momentum using a data sample of pp collision events at a centre-of-mass energy s=8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The Z boson is identified via its decay to a pair of muons. The measurement provides a precision test of quantum chromodynamics over a large region of phase space. In addition, due to the small experimental uncertainties in the measurement the data has the potential to constrain the gluon parton distribution function in the kinematic regime important for Higgs boson production via gluon fusion. The results agree with the next-to-next-to-leading-order predictions computed with the fewz program. The results are also compared to the commonly used leading-order MadGraph and next-to-leading-order powheg generators. © 2015 CERN for the benefit of the CMS Collaboration

Search for a low-mass pseudoscalar Higgs boson produced in association with a bb⁻ pair in pp collisions at √s=8 TeV

A search is reported for a light pseudoscalar Higgs boson decaying to a pair of tau leptons, produced in association with a b (b) over bar pair, in the context of two-Higgs-doublet models. The results are based on pp collision data at a centre-of-mass energy of 8 TeV collected by the CMS experiment at the LHC and corresponding to an integrated luminosity of 19.7 fb(-1). Pseudoscalar boson masses between 25 and 80 GeV are probed. No evidence for a pseudoscalar boson is found and upper limits are set on the product of cross section and branching fraction to tau pairs between 7 and 39 pb at the 95% confidence level. This excludes pseudoscalar A bosons with masses between 25 and 80 GeV, with SM-like Higgs boson negative couplings to down-type fermions, produced in association with bb pairs, in Type II, two-Higgs-doublet models. (C) 2016 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommonnorg/licensesiby/4.01)