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An SPH Framework for Earthquake-Induced Liquefaction Hazard Assessment of geotechnical Structures

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 251-277页

作者： Sourabh Mhaski g.V.Ramana Department of Civil Engineering Indian Institute of Technology DelhiNew Delhi110016India

Earthquake-induced soil liquefaction poses significant risks to the stability of geotechnical structures *** understanding of the liquefaction triggering,and the post-failure large deformation behaviour is essential for designing resilient *** present study develops a Smoothed Particle Hydrodynamics(SPH)framework for earthquake-induced liquefaction hazard assessment of geotechnical *** coupled flowdeformation behaviour of soils subjected to cyclic loading is described using the PM4Sand model implemented in a three-phase,single-layer SPH framework.A staggered discretisation scheme based on the stress particle SPH approach is adopted to minimise numerical inaccuracies caused by zero-energy modes and tensile ***,non-reflecting boundary conditions for seismic analysis of semi-infinite soil domains using the SPH method are *** numerical framework is employed for the analysis of cyclic direct simple shear test,seismic analysis of a level ground site,and liquefaction-induced failure of the Lower San Fernando *** agreement for liquefaction triggering and post-failure behaviour demonstrates that the SPH framework can be utilised to assess the effect of seismic loading on field-scale geotechnical *** present study also serves as the basis for future advancements of the SPH method for applications related to earthquake geotechnical engineering.

关键词： Earthquake seismic liquefaction stress particle PM4Sand smoothed particle hydrodynamics(SPH)

All-dielectric meta-optics and non-linear nanophotonics

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National Science Review 2018年第2期5卷 144-158页

作者： yuri Kivshar Nonlinear Physics Center Australian National University ITMO University

Most optical metamaterials fabricated and studied to date employ metallic components resulting in significant losses, heat and overall low efficiencies. A new era of metamaterial physics is associated with all-dielectric meta-optics, which employs electric and magnetic Mie resonances of subwavelength particles with high refractive index for an optically induced magnetic response, thus underpinning a new approach to design and fabricate functional and practical metadevices. Here we review the recent developments in meta-optics and subwavelength dielectric photonics and demonstrate that the Mie resonances can play a crucial role in the realization of the unique functionalities of meta-atoms, also driving novel effects in the fields of metamaterials and nanophotonics. We discuss the recent research frontiers in all-dielectric meta-optics and uncover how Mie resonances can be employed for a flexible control of light with full phase and amplitude engineering, including unidirectional metadevices, highly transparent metasurfaces,non-linear nanophotonics and topological photonics.

关键词： nanophotonics Mie resonances meta-optics metasurfaces metamaterials

Stepping up after spinal cord injury:negotiating an obstacle during walking

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Neural Regeneration Research 2025年第7期20卷 1919-1929页

作者： Alain Frigon Charly g.Lecomte Department of Pharmacology-Physiology Faculty of Medicine and Health SciencesUniversitéde SherbrookeCentre de recherche du Centre Hospitalier Universitaire de SherbrookeSherbrookeQCCanada

Every day walking consists of frequent voluntary modifications in the gait pattern to negotiate *** spinal cord injury,stepping over an obstacle becomes *** over an obstacle requires sensorimotor transformations in several structures of the brain,including the parietal cortex,premotor cortex,and motor *** information and planning are transformed into motor commands,which are sent from the motor cortex to spinal neuronal circuits to alter limb trajectory,coordinate the limbs,and maintain *** spinal cord injury,bidirectional communication between the brain and spinal cord is disrupted and animals,including humans,fail to voluntarily modify limb trajectory to step over an ***,in this review,we discuss the neuromechanical control of stepping over an obstacle,why it fails after spinal cord injury,and how it recovers to a certain extent.

关键词： biomechanics locomotion neurophysiology obstacle negotiation spinal cord injury

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LIVESTOCK PRODUCTION PLANNINg UNDER ENVIRONMENTAL RISKS AND UNCERTAINTIES

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Journal of Systems Science and Systems Engineering 2006年第4期15卷 399-418页

作者： günther FISCHER Tatiana ERMOLIEVA yuri ERMOLIEV Harrij van VELTHUIZEN International Institute for Applied Systems Analysis Schlossplatz 1 A-2361 Laxenburg Austria

In this paper we demonstrate the need for risk-adjusted approaches to planning expansion of livestock production. In particular, we illustrate that under exposure to risk, a portfolio of producers is needed where more efficient producers co-exist and cooperate with less efficient ones given that the latter are associated with lower, uncorre, lated or even negatively correlated contingencies. This raises important issues of cooperation and risk sharing among diverse producers. For large-scale practical allocation problems when information on the contingencies may be disperse, not analytically tractable, or be available on aggregate levels, we propose a downscaling procedure based on behavioral principles utilizing spatial risk preference structure, It allows for estimation of production allocation at required resolutions accounting for location specific risks and suitability constraints. The approach provides a tool for harmonization of data from various spatial levels. We applied the method in a case study of livestock production allocation in China to 2030.

关键词： Spatial production allocation sequential downscaling cross-entropy maximum likelihood risks and uncertainties.

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Polariton polarization rectifier

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Light(Science & Applications) 2019年第1期8卷 505-514页

作者： Evgeny S.Sedov yuri g.Rubo Alexey V.Kavokin Westlake University 18 Shilongshan RoadHangzhou 310024 Zhejiang ProvinceChina Institute of Natural Sciences Westlake Institute for Advanced Study18 Shilongshan RoadHangzhou 310024 Zhejiang ProvinceChina Vladimir State University Gorky str.87Vladimir 600000Russia Instituto de Energias Renovables Universidad Nacional Autonoma de Mexico62580 TemixcoMORMexico Spin Optics Laboratory Saint Petersburg State University1 UlianovskayaSt.Petersburg 198504Russia

We propose a novel photonic device,the polariton polarization rectifier,intended to transform polariton pulses with arbitrary polarization into linearly polarized pulses with controllable orientation of the polarization *** is based on the interplay between the orbital motion of the polariton wave packet and the dynamics of the polariton pseudospin governed by the spatially dependent effective magnetic *** latter is controlled by the TE-TM splitting in a harmonic *** show that the unpolarized polariton pulse acquires linear polarization in the course of propagation in a harmonic *** gives the considered structure an extra function as a linear polarizer of polariton pulses.

关键词： field polarized harmonic

Local-environment dependence of stacking fault energies in concentrated solid-solution alloys

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npj Computational Materials 2019年第1期5卷 1032-1038页

作者： Shijun Zhao yuri Osetsky g.Malcolm Stocks Yanwen Zhang Materials Science and Technology Division Oak Ridge National LaboratoryOak RidgeTN 37831USA Department of Mechanical Engineering City University of Hong KongHong KongChina Department of Materials Science and Engineering University of TennesseeKnoxvilleTN 37996USA

Concentrated solid-solution alloys(CSAs)based on 3d transition metals have demonstrated extraordinary mechanical properties and radiation resistance associated with their low stacking fault energies(SFEs).Owing to the intrinsic disorder,SFEs in CSAs exhibit distributions depending on local atomic *** this work,the distribution of SFEs in equiatomic CSAs of NiCo,NiFe,and NiCoCr are investigated based on empirical potential and first-principles *** show that the calculated distribution of SFEs in chemically disordered CSAs depends on the stacking fault area using empirical potential *** on electronic structure calculations,we find that local variations of SFEs in CSAs correlate with the charge density redistribution in the stacking fault *** further propose a bond breaking and forming model to understand and predict the SFEs in CSAs based on the local structure *** is shown that the perturbation induced by a stacking fault is localized in the first-nearest planes for NiCo,but extends up to the third nearest planes for NiFe and NiCoCr because of partially filled d electrons in Fe and Cr.

关键词： alloys fault stacking

Nitrogen and Carbon Isotope Data of Olenekian to Anisian Deposits from Kamenushka/South Primorye, Far-Eastern Russia and Their Palaeoenvironmental Significance

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Journal of Earth Science 2018年第4期29卷 837-853页

作者： yuri D Zakharov Micha Horacek Alexander M Popov Liana g Bondarenko Far Eastern geological Institute of Russian Academy of Sciences (Far Eastern Branch) Stoletiya Prospect 159 Vladivostok 690022 Russia BLT Wieselburg Research Center HBLFA Francisco-Josephinum Wieselburg 3250 Austria Institute of Lithospheric Research Vienna University Vienna 1090 Austria

The Kamenushka Formation, exposed in the northern part of South Primorye （Kamennshka-1 and Kamenushka-2 sections）, is one of the few localities in the world with richly fossiliferous Lower-Upper Olenekian sedimentary successions. Lower to Middle Triassic ammonoid-, brachiopod- and conodont-bearing silty-clayey deposits of the Kamenushka-1 and Kamenushka-2 sections have been isotope-geochemically investigated in detail. As a result, these sections, together with the previously investigated Abrek Section, exposed in the southern part of South Primorye, provide almost complete ^15Non- and ^13Corg- records for the Lower Triassic of this region. Nine N- isotope intervals and the five negative C-isotope excursions, reflecting, apparently, unstable climatic and hydrological conditions, have been distinguished in the Lower Triassic of South Primorye. On the basis of the new C-isotope data the Mesohedenstroemia bosphorensis Zone （upper part）, Shimanskyites shimanskyi and Neocolumbites insignis zones of South Primorye are correlated now with the Lower Smithian part of the Yinkeng Formation, the Upper Smithian part of the Helongshan Formation and the Middle Spathian part of the Nanlinghu Formation in South China, respectively, as has been observed in the Abrek, Kamenushka-2, West Pingdingshan and Majiashan sections.

关键词： Triassic N- and C-isotopes palaeoclimatology bio- and chemostratigraphy Pri- morye Russia.

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Approximations of the Fractional Integral and Numerical Solutions of Fractional Integral Equations

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Communications on Applied Mathematics and Computation 2021年第3期3卷 545-569页

作者： yuri Dimitrov Department of Mathematics and Physics University of Forestry1756 SofiaBulgaria Institute of Mathematics and Informatics Bulgarian Academy of Sciences1113 SofiaBulgaria

In the present paper,we derive the asymptotic expansion formula for the trapezoidal approximation of the fractional *** use the expansion formula to obtain approximations for the fractional integral of ordersα,1+α,2+α,3+αand 4+α.The approximations are applied for computation of the numerical solutions of the ordinary fractional relaxation and the fractional oscillation equations expressed as fractional integral equations.

关键词： Fractional integral Trapezoidal approximation Fractional integral equation Finite-difference scheme

Strengthening of tungsten by coherent rhenium precipitates formed during low fluence irradiation

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Tungsten 2022年第1期4卷 20-27页

作者： yuri Osetsky Materials Science and Technology Division Oak Ridge National LaboratoryOak RidgeTN 37831USA

Experimental data show that the accumulation of rhenium and osmium from transmutation reactions severely affect the microstructural evolution and property degradation of tungsten-based materials under neutron *** and modeling have confirmed that Re atom transport in W is by irradiation-produced migrating self-interstitial *** this diffusion mode in operation,a specific microstructure evolution is realized when at relatively low neutron fluence the Re-rich precipitates are formed,while the void and interstitial loop population development is suppressed,affecting the mechanical *** research shows the effect of small coherent Re-rich precipitates on the dislocation glide under stress,investigated using the molecular dynamics approach with empirical interatomic *** results are compared with an earlier simulation of void hardening in *** is demonstrated that small coherent Re-rich precipitates of less than 6 nm diameter represent relatively weak obstacles for moving edge *** implication of these results on the interpretation of experimental results is discussed.

关键词： Tungsten-rhenium alloys Molecular dynamics Re-rich precipitates Dislocation obstacle interaction Dislocation dynamics Obstacle strength