347 research outputs found

    On the comparative assessment of the investments’ economic efficiency in production capital

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    The article notes that in the current methodological document approved by government bodies on determining the investment projects effectiveness there are no recommendations for a comparative assessment of the economic efficiency of decisions made in the process of investment and construction activities, and at the same time their necessity is shown. The authors’ approaches to solving this problem are substantiated and presented. It is proposed to use income and property approaches in determining the economic efficiency of investment projects for the creation of new enterprises, industries, reconstruction and technical re-equipment of existing ones. The proposed methods and indicators are presented, which make it possible to give a comparative assessment of both investment projects as a whole and individual decisions on the choice of production technologies, technological and other equipment, design and construction solutions for buildings and structures

    Wave packet evolution approach to ionization of hydrogen molecular ion by fast electrons

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    The multiply differential cross section of the ionization of hydrogen molecular ion by fast electron impact is calculated by a direct approach, which involves the reduction of the initial 6D Schr\"{o}dinger equation to a 3D evolution problem followed by the modeling of the wave packet dynamics. This approach avoids the use of stationary Coulomb two-centre functions of the continuous spectrum of the ejected electron which demands cumbersome calculations. The results obtained, after verification of the procedure in the case atomic hydrogen, reveal interesting mechanisms in the case of small scattering angles.Comment: 7 pages, 8 Postscript figure

    Superaerophobic graphene nano-hills for direct hydrazine fuel cells

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    Hydrazine fuel-cell technology holds great promise for clean energy, not only because of the greater energy density of hydrazine compared to hydrogen but also due to its safer handling owing to its liquid state. However, current technologies involve the use of precious metals (such as platinum) for hydrazine oxidation, which hinders the further application of hydrazine fuel-cell technologies. In addition, little attention has been devoted to the management of gas, which tends to become stuck on the surface of the electrode, producing overall poor electrode efficiencies. In this study, we utilized a nano-hill morphology of vertical graphene, which efficiently resolves the issue of the accumulation of gas bubbles on the electrode surface by providing a nano-rough-edged surface that acts as a superaerophobic electrode. The growth of the vertical graphene nano-hills was achieved and optimized by a scalable plasma-enhanced chemical vapor deposition method. The resulting metal-free graphene-based electrode showed the lowest onset potential (-0.42 V vs saturated calomel electrode) and the highest current density of all the carbon-based materials reported previously for hydrazine oxidation

    Development of the Northern Sea Route on the Route Murmansk-Vladivostok-Shanghai (China)

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    The paper considers the development of the Northern Sea Route (NSR) in modern Russia and China. The analysis of cargo turnover and the advantages of the NSR is carried out. The importance of the nuclear icebreaker fleet in the development of the NSR is determined and specified. The route is currently considered as transcontinental and it is planned to become part of the “Silk Road”. It belongs to the number of Russian national projects. As an international transit highway, the Northern Sea Route has a huge potential for international cooperation and development of the North and East of Russia. The cluster-modular approach in the organization of NSR is considered. © 2022 The Authors. Published by ELSEVIER B.V

    Adiabatic description of nonspherical quantum dot models

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    Within the effective mass approximation an adiabatic description of spheroidal and dumbbell quantum dot models in the regime of strong dimensional quantization is presented using the expansion of the wave function in appropriate sets of single-parameter basis functions. The comparison is given and the peculiarities are considered for spectral and optical characteristics of the models with axially symmetric confining potentials depending on their geometric size making use of the total sets of exact and adiabatic quantum numbers in appropriate analytic approximations

    Imaging the square of the correlated two-electron wave function of a hydrogen molecule

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    The toolbox for imaging molecules is well-equipped today. Some techniques visualize the geometrical structure, others the electron density or electron orbitals. Molecules are many-body systems for which the correlation between the constituents is decisive and the spatial and the momentum distribution of one electron depends on those of the other electrons and the nuclei. Such correlations have escaped direct observation by imaging techniques so far. Here, we implement an imaging scheme which visualizes correlations between electrons by coincident detection of the reaction fragments after high energy photofragmentation. With this technique, we examine the H2two-electron wave function in which electron-electron correlation beyond the mean-field level is prominent. We visualize the dependence of the wave function on the internuclear distance. High energy photoelectrons are shown to be a powerful tool for molecular imaging. Our study paves the way for future time resolved correlation imaging at FELs and laser based X-ray sourcesThis work was funded by the Deutsche Forschungsgemeinschaft, the BMBF, the European Research Council under the European Union Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement 290853 XCHEM, the MINECO projects FIS2013-42002-R and FIS2016-77889-R, and the European COST Action XLIC CM1204. All calculations were performed at the CCC-UAM and Mare Nostrum Supercomputer Centers. We are grateful to the staff of PETRA III for excellent support during the beam time. K.M. and M.M. would like to thank the DFG for support via SFB925/A3. A.K. and V.S. thank the Wilhelm und Else Heraeus-Foundation for support. J.L. would like to thank the DFG for support. S.K. acknowledges support from the European Cluster of Advanced Laser Light Sources (EUCALL) project which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 654220. T.W. was supported by the U.S. Department of Energy Basic Energy Sciences under Contract No. DE-AC02-05CH11231. A.P. acknowledges a Ramón y Cajal contract from the Ministerio de Economa y Competitivida

    Measurement of Inclusive Spin Structure Functions of the Deuteron

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    We report the results of a new measurement of spin structure functions of the deuteron in the region of moderate momentum transfer (Q2Q^2 = 0.27 -- 1.3 (GeV/c)2^2) and final hadronic state mass in the nucleon resonance region (WW = 1.08 -- 2.0 GeV). We scattered a 2.5 GeV polarized continuous electron beam at Jefferson Lab off a dynamically polarized cryogenic solid state target (15^{15}ND3_3) and detected the scattered electrons with the CEBAF Large Acceptance Spectrometer (CLAS). From our data, we extract the longitudinal double spin asymmetry AA_{||} and the spin structure function g1dg_1^d. Our data are generally in reasonable agreement with existing data from SLAC where they overlap, and they represent a substantial improvement in statistical precision. We compare our results with expectations for resonance asymmetries and extrapolated deep inelastic scaling results. Finally, we evaluate the first moment of the structure function g1dg_1^d and study its approach to both the deep inelastic limit at large Q2Q^2 and to the Gerasimov-Drell-Hearn sum rule at the real photon limit (Q20Q^2 \to 0). We find that the first moment varies rapidly in the Q2Q^2 range of our experiment and crosses zero at Q2Q^2 between 0.5 and 0.8 (GeV/c)2^2, indicating the importance of the Δ\Delta resonance at these momentum transfers.Comment: 13 pages, 8 figures, ReVTeX 4, final version as accepted by Phys. Rev.
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