2,288 research outputs found
Sc, Cr, Co, Ni, Th and rare earth elements systematics in black shales of Murav’inskaya and Velsovskaya formations (Lyapin-Kutim anticlinorium, the Northern Urals): to the provenance reconstructions
The features of the Sc, Cr, Co, Ni, Th and rare earth elements distribution in the black shales of the Riphean Murav’inskaya and Velsovskaya formations in southern part of the Lyapin-Kutim anticlinorium (Northern Ural) are analyzed. The contents of the listed elements in 20 samples of black shales are determined by the ICP-MS method at the IGG UB RAS (Ekaterinburg). Samples of the shales of the Murav’insky formation are selected from the outcrops along the river Vels, below the mouth of Pos’mak River, as well as along Pravaya Rassokha River. The selection was made from outcrops more or less evenly distributed over the studied area. The shales of the Velsovskaya formation were studied from the drilling holes in the basin of Sur’ya Vagranskaya River, as well as in outcrops along the Sibiryakovskaya Martayka and Pravaya Rassokha rivers. In the Sc-Th/Sc diagram, the data points of the black shales of the Murav’inskaya and Velsovskaya formations are fairly compact located between the points of the average composition of the Archean and Proterozoic granites, on the one hand, and tonalite-trondhjemite-granite (TTG) associations of the same age. Approximately the same distribution of the data points of the black shales of these formations can be seen in the La/Sc-Th/Co and La/Sm-Sc/Th diagrams. The average value of ΣРЗЭ in black shales of the Murav’inskaya formation is 316 ± 90 ppm, in the shales of the Velsovskaya Formation it is noticeably lower - 200 ± 47 ppm. The black shales of the Murav’inskaya Formation are substantially enriched with light lanthanides (La/Yb)Nmean = 40, and noticeably depleted by heavy lanthanides, (Gd/Yb)Nmean = 5.4. For the black shales of the Velsovsky formation (La/Yb)Nmean = 22, (Gd/Yb)Nmean = 3.1. This ones and a number of the other data make it possible to conclude that the complexes of rock-sources of fine aluminosiliciclastics for black shales of Murav’inskaya and Velsovskaya formations had a rather specific composition. On the basis of a comparison of the geochemical features of the black shales of the southern part of the Lyapin-Kutim anticlinorium and potential sources of fine aluminosiliciclastics, the conclusion is based that such rock complexes could be, from one side, the Archean and/or Proterozoic TTG associations and granites of the same age of the Eastern European platform, and, from another side, certain local rocks with high Cr contents and significant differentiation of REE, similar in composition to the products of kimberlite magmatism
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The electronic structure and the nature of the chemical bond in CeO2.
The X-ray photoelectron spectral structure of CeO2 valence electrons in the binding energy range of 0 to ∼50 eV was analyzed. The core-electron spectral structure parameters and the results of relativistic discrete-variational calculations of CeO8 and Ce63O216 clusters were taken into account. Comparison of the valence and the core-electron spectral structures showed that the formation of the inner (IVMO) and the outer (OVMO) valence molecular orbitals contributes to the spectral structure more than the many-body processes. The Ce 4f electrons were established to participate directly in chemical bond formation in CeO2 losing partially their f character. They were found to be localized mostly within the outer valence band. The Ce 5p atomic orbitals were shown to participate in the formation of both the inner and the outer valence molecular orbitals (MOs). A large part in the IVMO formation is taken by the filled Ce 5p1/2, 5p3/2 and O 2s atomic shells, while the Ce 5s electrons participate weakly in the chemical bond formation. The composition and the sequent order of the molecular orbitals in the binding energy range of 0 to ∼50 eV were established. A quantitative scheme for the molecular orbitals of CeO2 was built. This scheme is fundamental for understanding the nature of chemical bonding and also for the interpretation of other X-ray spectra of CeO2. Evaluations revealed that the IVMO electrons weaken the chemical bond formed by the OVMO electrons by 37%.The work was supported by the RFBR grant № 17-03-00277a. M.V. Ryzhkov acknowledges financial support of FASO of Russia ISSC of the Ural Branch of RAS № AAAA-A16-116122810214-9. A.J. Popel acknowledges funding from the UK EPSRC (grant EP/I036400/1) and Radioactive Waste Management Ltd (formerly the Radioactive Waste Management Directorate of the UK Nuclear Decommissioning Authority, contract NPO004411A-EPS02), a maintenance grant from the Russian Foundation for Basic Research (projects 13-03-90916) and CSAR bursary
Superlattices of Gadolinium and Bismuth Based Thallium Dichalcogenides as Potential Magnetic Topological Insulators
Using relativistic spin-polarized density functional theory calculations we investigate magnetism, electronic structure and topology of the ternary thallium gadolinium dichalcogenides TlGdZ2 (Z= Se and Te) as well as superlattices on their basis. We find TlGdZ2 to have an antiferromagnetic exchange coupling both within and between the Gd layers, which leads to frustration and a complex magnetic structure. The electronic structure calculations reveal both TlGdSe2 and TlGdTe2 to be topologically trivial semiconductors. However, as we show further, a three-dimensional (3D) magnetic topological insulator (TI) state can potentially be achieved by constructing superlattices of the TlGdZ2/(TlBiZ2)n type, in which structural units of TlGdZ2 are alternated with those of the isomorphic TlBiZ2 compounds, known to be non-magnetic 3D TIs. Our results suggest a new approach for achieving 3D magnetic TI phases in such superlattices which is applicable to a large family of thallium rare-earth dichalcogenides and is expected to yield a fertile and tunable playground for exotic topological physics.M.M.O. and M.B. acknowledge the support by Spanish Ministerio de Ciencia e Innovación (Grant No. PID2019-103910GB-I00) and the University of the Basque Country (Grant no. IT1527-22). A.Yu.V. and E.K.P. acknowledge support from the Ministry of Education and Science of the Russian Federation within State Task No. FSWM-2020-0033 (in the part of bulk and surface electronic structure calculations). E.V.C. acknowledges support from Saint Petersburg State University (Grant ID No. 90383050). Yu.M.K. acknowledges support from the Government research assignment for ISPMS SB RAS, project FWRW-2022-0001 (in the part of the topological classification of bulk band structure)
Microstructured optical waveguide-based endoscopic probe coated with silica submicron particles
Microstructured optical waveguides (MOW) are of great interest for chemical and biological sensing. Due to the high overlap between a guiding light mode and an analyte filling of one or several fiber capillaries, such systems are able to provide strong sensitivity with respect to variations in the refractive index and the thickness of filling materials. Here, we introduce a novel type of functionalized MOWs whose capillaries are coated by a layer-by-layer (LBL) approach, enabling the alternate deposition of silica particles (SiO2) at different diameters—300 nm, 420 nm, and 900 nm—and layers of poly(diallyldimethylammonium chloride) (PDDA). We demonstrate up to three covering bilayers consisting of 300-nm silica particles. Modifications in the MOW transmission spectrum induced by coating are measured and analyzed. The proposed technique of MOW functionalization allows one to reach novel sensing capabilities, including an increase in the effective sensing area and the provision of a convenient scaffold for the attachment of long molecules such as protein
Recommended reading list of early publications on atomic layer deposition-Outcome of the "Virtual Project on the History of ALD"
Atomic layer deposition (ALD), a gas-phase thin film deposition technique based on repeated, self-terminating gas-solid reactions, has become the method of choice in semiconductor manufacturing and many other technological areas for depositing thin conformal inorganic material layers for various applications. ALD has been discovered and developed independently, at least twice, under different names: atomic layer epitaxy (ALE) and molecular layering. ALE, dating back to 1974 in Finland, has been commonly known as the origin of ALD, while work done since the 1960s in the Soviet Union under the name "molecular layering" (and sometimes other names) has remained much less known. The virtual project on the history of ALD (VPHA) is a volunteer-based effort with open participation, set up to make the early days of ALD more transparent. In VPHA, started in July 2013, the target is to list, read and comment on all early ALD academic and patent literature up to 1986. VPHA has resulted in two essays and several presentations at international conferences. This paper, based on a poster presentation at the 16th International Conference on Atomic Layer Deposition in Dublin, Ireland, 2016, presents a recommended reading list of early ALD publications, created collectively by the VPHA participants through voting. The list contains 22 publications from Finland, Japan, Soviet Union, United Kingdom, and United States. Up to now, a balanced overview regarding the early history of ALD has been missing; the current list is an attempt to remedy this deficiency. (C) 2016 Author(s).Peer reviewe
Report of the 2021 U.S. Community Study on the Future of Particle Physics (Snowmass 2021) Summary Chapter
The 2021-22 High-Energy Physics Community Planning Exercise (a.k.a.
``Snowmass 2021'') was organized by the Division of Particles and Fields of the
American Physical Society. Snowmass 2021 was a scientific study that provided
an opportunity for the entire U.S. particle physics community, along with its
international partners, to identify the most important scientific questions in
High Energy Physics for the following decade, with an eye to the decade after
that, and the experiments, facilities, infrastructure, and R&D needed to pursue
them. This Snowmass summary report synthesizes the lessons learned and the main
conclusions of the Community Planning Exercise as a whole and presents a
community-informed synopsis of U.S. particle physics at the beginning of 2023.
This document, along with the Snowmass reports from the various subfields, will
provide input to the 2023 Particle Physics Project Prioritization Panel (P5)
subpanel of the U.S. High-Energy Physics Advisory Panel (HEPAP), and will help
to guide and inform the activity of the U.S. particle physics community during
the next decade and beyond.Comment: 75 pages, 3 figures, 2 tables. This is the first chapter and summary
of the full report of the Snowmass 2021 Workshop. This version fixes an
important omission from Table 2, adds two references that were not available
at the time of the original version, fixes a minor few typos, and adds a
small amount of material to section 1.1.
Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires
The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of , and is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 0.02 \mbox{fb}^{-1}. The bosons are reconstructed in the decays , where denotes muon or electron, while the and quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions
Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV
Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an
Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
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