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Tourmalinization at the Darasun goldfield,Eastern Transbaikalia:Compositional,fluid inclusion and isotopic constraints

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Geoscience Frontiers 2012年第1期3卷 59-71页

作者： Vsevolod Prokofiev Ivan Baksheev Lidiya Zorina Boris Belyatsky vladimir ustinov Nadezhda Krivitskaya Institute of Geology of Ore Deposits Petrography Mineralogy & GeochemistryRussian Academy of SciencesMoscowRussia Lomonosov Moscow State University MoscowRussia Lomonosov Moscow State University Moscow Russia Vinogradov Institute of Geochemistry Irkutsk Russia Institute of Precambrian Geology and Geochronology RAS Saint-PetersburgRussia Vernadsky Institute of Geochemistry and Analytical Chemistry RAS MoscowRussia

Zoned tourmaline （schorl-dravite） in the matrix of hydrothermal explosive breccia and ore veins in gold deposits, Chita region, Eastern Transbaikalia, Russia, are associated with Na- and K-rich porphyry-type subvolcanic intrusives. 61So values of tourmaline from three gold deposits （Darasun, Talatui, Teremkinskoye） are ＋8.3%, ＋7.6%, and --6.0% and calculated 6180 values of fluids respon- sible for the tourmalinization are ＋7.3%, ＋7.7%, and ＋4.2%, respectively. These data imply an igneous fluid source, except at the Teremkin deposit where mixing with meteoric water is indicated. Wide ranges of Fe3＋/Fetot and the presence of vacancies characterize the Darasun deposit tourmaline indicating wide ranges off（O2） and pH of mineralizing fluids. Initial stage tourmalines from the gold deposits of the Darasun ore district are dravite or high mg schorl. Second stage tourmaline is characterized by oscillatory zoning but with Fe generally increasing towards crystal rims indicating decreasing temperature. Third stage tourmaline formed unzoned crystals with XMg （mole fraction of Mg） close to that of the first stage tourmaline, due to a close association with pyrite and arsenopyrite. From Fe^3＋/Fetot values, chemical composition and crystallization temperatures, logf（O2） of mineralizing fluids ranged from ca. -25 to 20, much higher than for the gold-bearing beresite-listvenite association, indicating that tourmalinization was not related to gold mineralization.

关键词： Tourmaline composition Fluid inclusions Oxygen isotopes Gold deposits Transbaikalia Russia

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Incubation time fracture criterion for FEM simulations

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Acta Mechanica Sinica 2011年第4期27卷 541-549页

作者： vladimir Bratov Institute for Problem in Mechanical Engineering of the Russian Academy of Sciences Bolshoj pr.V.O.61199178St.-PetersburgRussia

The paper is discussing problems connected with embedment of the incubation time criterion for brittle fracture into finite element computational schemes. Incubation time fracture criterion is reviewed; practical questions of its numerical implementation are extensively discussed. Several examples of how the incubation time fracture criterion can be used as fracture condition in finite element computations are given. The examples include simulations of dynamic crack propagation and arrest, impact crater formation （i.e. fracture in initially intact media）, spall fracture in plates, propagation of cracks in pipelines. Applicability of the approach to model initiation, development and arrest of dynamic fracture is claimed.

关键词： Fracture dynamics Incubation time Crack dy-namics Finite element method Fracture arrest

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Features of Electroplastic Effect in Alloys with Martensite Transformation

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Acta Metallurgica Sinica(English Letters) 2018年第12期31卷 1305-1310页

作者： vladimir Stolyarov Mechanical Engineering Research Institute RussianAcademy of SciencesM.Kharitonievsky4MoscowRussia 101990 National Research Nuclear University MEPhI MoscowRussia

Influence of different electric current modes （pulse and direct） on occurrence of the electroplastic effect under uniaxialtension in the coarse-grained alloys with martensite transformations is investigated. The materials are shape memoryTi49.3Niso.7 alloy and metastable austenite transformation-induced plasticity （TRIP） steel. The paper contains experimentalresults of current impact on the ＂stress-strain＂ curves of the material. It has been taken an experimental measurement ofthe sample temperature during the test. It is shown that the shape of a stress-strain curves and type of the serrate plasticflow, connected with the martensitic transformation and electroplastic effect, depend on the current modes. Impact of pulsecurrent and direct current suppresses shape memory and TRIP effect.

关键词： Electroplastic effect TRIP effect Pulse current Deformation Martensite transformation Tension

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Thermoelectric and electrical characteristics of SmS ceramic samples after exposure to a pulsed magnetic field

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Journal of Rare Earths 2022年第11期40卷 1778-1784,I0004页

作者： Ivan Volchkov Evgeniy Baskakov vladimir Strelov vladimir Kanevskii FSRC"Crystallography and Photonics"RAS Leninskiy Prospekt 59119333MoscowRussia

Samarium monosulfide(SmS)is a promising material for creating thermoelectric generators(TEG),gas sensors and strain *** the high values of the generated thermo electromotive force(TEMF)(α≈170-350μV/K),methods for increasing the efficiency of TEGs based on SmS are of considerable *** of these methods can be short-term effects of magnetic fields,including pulsed ones,on these *** action of a pulsed magnetic field(PMF)leading to an increase in TEMF(U)of SmS ceramic samples is *** that are not subjected to high frequency currents(HFC)annealing show an increase in UT of 44.54%-62.18%(from 11.9 to 17.2-19.3 mV).The conductivity(σ)of the samples is~22 Q/cm and is insensitive to short-term exposure to a *** that undergo HFC annealing show an increase in Uof 23.47%-41.31%(from 21.3 to 26.3-30.1 mV)after exposure to a *** conductivity of the samples is~15Ω^(-1)/cm and after a short exposure to the PMF is changing nonmo notonically,with an increase in the overall *** difference in the values of Uand a can be explained by presence of an ordered grain structure and a significant amount of the Sm_(2)O_(2)S phase in the samples subjected to HFC *** mechanisms of the observed changes are discussed.

关键词： Rare earths Thermoelectric Electric properties Magnetically induced changes Samarium monosulfide

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Integer Codes Correcting Single Errors and Random Asymmetric Errors within a Byte

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Journal of Systems Science & Complexity 2020年第6期33卷 2103-2113页

作者： RADONJIC Aleksandar VUJICIC vladimir Institute of Technical Sciences of the Serbian Academy of Sciences and Arts BelgradeSerbia

In optical networks without optical amplifiers(ONWOAs) photons may fade or fail to be detected, but new photons cannot be generated. Hence, under normal conditions, only 1 → 0 errors can occur. However, in some situations, the photodetector may generate a false 0 → 1 error. This mostly occurs in cases when the dark current is higher than specified. With this in mind, in this paper,the authors present a class of codes suitable for use in ONWOAs using self-synchronous *** presented codes can correct single errors and random asymmetric(1 → 0) errors within a b-bit byte. Unlike classical codes, these codes use integer and lookup table operations. As a result, their interleaved version, implemented on a dual-core 3.0 GHz processor, achieves the theoretical throughput above the operating rate of 10 G networks.

关键词： Asymmetric errors decoding throughput integer codes optical networks single errors

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Advanced virtual prototyping for cyber-physical systems using RISC-V: implementation, verification and challenges

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Science China(Information Sciences) 2022年第1期65卷 5-21页

作者： vladimir HERDT Rolf DRECHSLER Institute of Computer Science University of Bremen Cyber-Physical Systems DFKI Gmb H

Virtual prototypes(VPs) are crucial in today’s design flow. VPs are predominantly created in System C transaction-level modeling(TLM) and are leveraged for early software development and other system-level use cases. Recently, virtual prototyping has been introduced for the emerging RISC-V instruction set architecture(ISA) and become an important piece of the growing RISC-V ecosystem. In this paper, we present enhanced virtual prototyping solutions tailored for RISC-V. The foundation is an advanced open source RISC-V VP implemented in System C TLM and designed as a configurable and extensible *** scales from small bare-metal systems to large multi-core systems that run applications on top of the Linux operating system. Based on the RISC-V VP, this paper also discusses advanced VP-based verification approaches and open challenges. In combination, we provide for the first time an integrated and unified overview and perspective on advanced virtual prototyping for RISC-V.

关键词： virtual prototyping RISC-V SystemC TLM verification

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Technological lubricating means： Evolution of materials and ideas

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Frontiers of Mechanical Engineering 2016年第1期11卷 101-107页

作者： vladimir A. GODLEVSKIY Department of Physics Ivanovo State University Ivanovo 153025Russia

The main stages of technological lubricating material development from ancient times to date are described. How the chemical composition of these products changed with time, how new ideas revealing the physical and chemical basics of external media that influence the mechanical processing of materials appeared, how these ideas explained the differences between traditional tribology and specific technology of metal processing are discussed. The question of the possible realization of Rehbinder＇s adsorption effect in contact zone is also stated. The description of a very captivating problem is related to the explanation of the mechanism of lubricant penetration into the contact zone between the material being processed and the tool. The birth and development of the hypothesis of microcapillary penetra- tion of the lubricant into the dynamically changed intersurface clearance that has finally led to formulating the ＂necessary kinetic condition of the lubricating activity＂ is relayed.

关键词： technological lubrication and cooling metal cutting grinding lubrication action tribology

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Effect of Y_2O_3 and Total Oxide Addition on Mechanical Properties of Pressureless Sintered β-SiC

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Journal of Materials Science & Technology 2003年第3期19卷 193-196页

作者： vladimir D.Krstic Centre for Manufacturing of Advanced Ceramics and Nanomaterials Queen’s UniversityNicol HallKingstonOntarioCanada K7L 3N6

The effect of Y203 and the total oxide volume fraction (Y203+AI203) on density and mechanical properties of low temperature (1770-1940℃) pressureless sintered β-SiC ceramics were presented. The optimum temperature for pressureless sintering of β-SiC was found to be -1850℃ and the optimum content of Y203 in the oxides was found to be between 40 and 57 wt pct. The highest sintered density was achieved by adding oxides at 14 vol. pct. Both of the highest strength and fracture toughness were achieved at -14 vol. pct oxide addition and yttria concentrations between 40 and 57 wt pct in the oxides. Hardness, on the other hand, was found to be the highest for samples with 14 vol. pct oxide addition and -64 wt pct Y2O3 in oxides.

关键词： Y_2O_3 SiC Mechanical properties Sintering

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Elaboration of a conceptual solution for the development of the Arctic shelf from seasonally flooded coastal areas

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International Journal of Mining Science and Technology 2022年第1期32卷 113-119页

作者： vladimir S.Litvinenko Mikhail V.Dvoynikov vladimir L.Trushko Saint-Petersburg Mining University Saint-Petersburg 199106Russia

Currently,construction of facilities in the Arctic is carried out on sand islands,but there are limitations for remote coastal *** restrictions are associated with the lack of quarries with construction sand in the immediate vicinity of the work site,as well as the risk of seasonal flooding of the *** article includes conceptual solutions for construction of modular piling in Arctic nearshore conditions,upon which drilling rigs and auxiliary equipment can be placed for the purpose of subsequent wildcatting,development and exploratory extended reach drilling wells(with measured depth about 15000 m).During the construction of the modular piling foundations,a mathematical simulation of the thermodynamic condition of the frozen ground was conducted,and the bearing capacity of the foundations was *** proposed solutions will solve these problems by constructing modular pile foundations and placing the necessary infrastructure on them,taking into account the distribution of loads during operation in seasonally flooded areas.

关键词： Drilling&drillholes Stress analysis Offshore engineering Infrastructure planning Geotechnical engineering Extended reach drilling

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A theory to link relationships of stand volume,density,mean diameter and height in forestry data

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Journal of Forestry Research 2021年第1期32卷 15-20页

作者： vladimir L.Gavrikov Chair of Ecology and Environmental Studies Institute Ecology and GeographySiberian Federal University79 pr.SvobodnyiKrasnoyarskRussian Federation 660041

In this study,a geometric model of a growing forest stand has been *** basic relationships considered link stand volume and stand density,diameter at breast height(DBH),mean DBH and mean *** model provides simple formulas connecting the exponents of all the *** of the formulas to real forestry data provided a high level of predictions of an exponent from two others measured through regressions from empirical *** Pinus sylvestris *** were of a static nature,a collection of individual stands,while the Pseudotsuga menziesii(Mirb.)Franco data were dynamic,representing forest stand development over *** ability of the model to predict exponents in the empirical data implies,on the one hand,a substantial level of similarity between the model and the forestry ***,on the other hand,the model gives an example in which parameters of one relationship may be linked to parameters of *** this kind of‘relationship between relationships’may be observed in forest stands undergoing active growth and competition-induced self-thinning.

关键词： Relationship between relationships Selfthinning Forestry data Allometry Scots pine Douglasfir

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