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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

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

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

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

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 mboxRISC-V SystemC TLM verification

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Measurement of trace element content in bone samples using long-lived neutron activation products and high-resolution gamma-ray spectrometry

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Nuclear Science and Techniques 2016年第1期27卷 21-28页

作者： vladimir Zaichick Sofia Zaichick Radionuclide Diagnostics Department Medical Radiological Research Centre Department of Medicine University of Illinois College of Medicine at Chicago

A nondestructive instrumental neutron activation analysis with high-resolution gamma-ray spectrometry of long-lived radionuclides was developed and used for measurement of trace element contents in samples of bone to determine health and diseases. Using this method, the silver(Ag), cobalt(Co), chromium(Cr), iron(Fe), mercury(Hg), rubidium(Rb), antimony(Sb), selenium(Se), and zinc(Zn) mass fractions were estimated in bone samples from 27 patients with intact bone(12 females and 15 males, aged from 16 to 49 years) who had died from various non-bone-related causes, mainly unexpected traumas,and from 5 patients with chondroma(2 females and 3males, 15–42 years old), obtained from open biopsies or after operation. The reliability of the differences in the results between intact bone and bone affected by chondroma was evaluated by a parametric Student's t test and a nonparametric Mann–Whitney U test. It was found that in the bone affected by chondroma, the mean mass fractions of Co, Cr, Fe, Se, Sb, and Zn were significantly higher than in normal bone tissues. In the neoplastic bone, many correlations between trace elements found in the control group were no longer evident. This work revealed that there is asignificant disturbance of the trace element metabolism in bone affected by chondroma.

关键词：微量元素含量高分辨率中子活化长寿命 γ能谱法活化产物样品测定

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

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

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