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Transient near tip fields in crack dynamics

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Science China(Physics,Mechanics & Astronomy) 2011年第7期54卷 1309-1318页

作者： BRATOV Vladimir PETROV yuri UTKIN Alexander Institute of Problems of Mechanical Engineering Russian Academy of SciencesSt.-Petersburg 199178Russia St.-Petersburg State University St.-Petersburg 198504Russia

Transient effects of stress-strain fields in the vicinity of a stationary crack tip under high rate loads are *** analytical solutions to near tip stresses are compared to fields prescribed by leading terms(one or several) of williams asymptotic *** of load application mode,time(or,which is the same,distance from a crack tip) and Poisson's ratio on this discrepancy is extensively *** effects connected with crack tip propagation speed are also *** inconsistencies between real(or received in numerical solutions of state *** element computations) crack tip fields and stress intensity factor(SIF) singular field observed by numerous researchers are *** scope of problems where SIF field can be used for correct prediction of dynamic stress-strain fields in the crack tip region is *** to correctly approximate fields that are not SIF dominated,accounting additional terms of williams expansion,is studied.

关键词： transient crack tip fields dynamic fracture high-rate loads asymptotic expansions

Critical regular components of IT strategy:Decision making model and efficiency measurement

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Journal of Management Analytics 2015年第2期2卷 95-110页

作者： yuri Zelenkov NPO Saturn RybinskRussia Department of Applied Informatics Financial University under the Governmant of the Russian FederationMoscowRussia

Existing approaches suggest that IT strategy should be a reflection of business ***,actually organizations do not often follow business strategy even if it is formally *** these conditions,IT strategy can be viewed not as a plan,but as an organizational shared view on the role of information *** approach generally reflects only a top-down perspective of IT *** it can be supplemented by a strategic behavior pattern(*** or less standard response to a change that is formed as result of previous experience)to implement a bottom-up *** critical regular components that establish the behavioral pattern regarding IT are proposed here:a model of IT-related decision making,and an efficiency measurement metric to estimate the maturity of business processes and appropriate *** of proposed tools is demonstrated in practical cases.

关键词： information systems decision analysis general management operations management engineering management

Incubation time approach in rock fracture dynamics

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Science China(Physics,Mechanics & Astronomy) 2012年第1期55卷 78-85页

作者： SMIRNOV V PETROV yuri V BRATOV V St.-Petersburg State Transport University 198103 St.-Petersburg Russia St.-Petersburg State University 198504 St.-Petersburg Russia Institute of Problems of Mechanical Engineering Russian Academy of Sciences 199178 St.-Petersburg Russia

The paper is summarizing latest results connected with application of the incubation time approach to problems of dynamic fracture of rock materials. Incubation time based fracture criteria for intact media and media with cracks are discussed. Available experimental data on high rate fracture of different rock materials and incubation time based fracture criteria are used in order to evaluate critical parameters of causing fracture in these materials. Previously discovered possibility to optimize (minimize) energy input for fracture is discussed in connection to industrial rock fracture processes. It is shown that optimal value of momentum associated with critical load in order to initialize fracture in rock media does strongly depend on the incubation time and the impact duration. Existence of optimal load shapes minimizing momentum for a single fracturing impact or a sequence of periodic fracturing impacts is demonstrated.

关键词： incubation time dynamic fracture rocks dynamic strength fracture toughness crack resistance energy and momentum input fracture process optimization

Short-term microbial responses to soluble inorganic P input in a tropical lowland rain forest in Amazonia

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Pedosphere 2021年第6期31卷 964-972页

作者： yuri w.L.DE SOUSA Erika BUSCARDO Carlos A.N.QUESADA Henrique E.M.NASCIMENTO Laszlo NAGY National Research Institute for Amazonia Manaus 69067-375(Brazil) Department of Forestry University of BrasiliaBrasilia 70910-900(Brazil) Centre for Functional Ecology University of CoimbraCoimbra 3000-456(Portugal) Department of Animal Biology University of CampinasCampinas 13083-862(Brazil)

In non-flooded lowland rain forests with low soil phosphorus(P)in parts of Amazonia,P cycling largely occurs via leaf litter recycling by arbuscular mycorrhizal(AM)fungal *** high input of P into these ecosystems occurs during drought years with increased *** the length and frequency of drought events are projected to increase in the region,a single-dose nutrient addition experiment was carried out to test how this would impact P *** application rate of 4 kg P ha^(-1) was used,which corresponds to twice the amount of litter-derived P in an average *** was hypothesized that i)the added mineral P would be immobilized by soil microorganisms,leading to measurable increase in soil microbial biomass carbon(C)and P and ii)AM colonization rate would be reduced by the pulse in mineral P available for plant *** results did not support either of our *** addition of P did not have an effect on AM root colonization,nor was P immobilized by soil microbiota during the experimental *** lack of a difference between the control and treatment at our study site could be attributed to the relatively low one-off dose of P applied that did not change either the colonization rate of roots by AM fungi or the amount of soil available labile *** obtain a mechanistic understanding of the availability,capture,and use of P by plant-symbiont associations in tropical rain forest ecosystems,further integrated studies of the soil-plant system combining long-term nutrient manipulations,modeling,and experimental approaches are required.

关键词： Amazon basin arbuscular mycorrhizal fungi nutrient addition phosphorus cycling soil microbial biomass

Intelligent metaphotonics empowered by machine learning

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Opto-Electronic Advances 2022年第3期5卷 1-24页

作者： Sergey Krasikov Aaron Tranter Andrey Bogdanov yuri Kivshar Nonlinear Physics Center Research School of PhysicsThe Australian National UniversityCanberra ACT 2601Australia School of Physics and Engineering ITMO UniversitySt.Petersburg 197101Russia Centre for Quantum Computation and Communication Technology Department of Quantum ScienceResearch School of PhysicsThe Australian National UniversityCanberraACT 2601Australia

In the recent years,a dramatic boost of the research is observed at the junction of photonics,machine learning and artifi-cial intelligence.A new methodology can be applied to the description of a variety of photonic systems including optical waveguides,nanoantennas,and *** novel approaches underpin the fundamental principles of light-matter interaction developed for a smart design of intelligent photonic *** intelligence and machine learn-ing penetrate rapidly into the fundamental physics of light,and they provide effective tools for the study of the field of metaphotonics driven by optically induced electric and magnetic *** we overview the evaluation of meta-photonics induced by artificial intelligence and present a summary of the concepts of machine learning with some specif-ic examples developed and demonstrated for metasystems and metasurfaces.

关键词： metaphotonics machine learning artificial intelligence

cell2mol:encoding chemistry to interpret crystallographic data

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npj Computational Materials 2022年第1期8卷 1787-1794页

作者： Sergi Vela Ruben Laplaza yuri Cho Clémence Corminboeuf Laboratory for Computational Molecular Design(LCMD) Institute of Chemical Sciences and Engineering(ISIC)École Polytechnique Fédérale de Lausanne(EPFL)CH-1015LausanneSwitzerland National Centre for Computational Design and Discovery of Novel Materials(NCCR MARVEL) Ecole Polytechnique Fédérale de Lausanne1015LausanneSwitzerland National Centre for Competence in Research“Sustainable chemical processes through catalysis(NCCR Catalysis)” École Polytechnique Fédérale de Lausanne1015LausanneSwitzerland

The creation and maintenance of crystallographic data repositories is one of the greatest data-related achievements in *** such as the Cambridge Structural Database host what is likely the most diverse collection of synthesizable *** properly mined,they could be the basis for the large-scale exploration of new regions of the chemical space using quantum chemistry(QC).Yet,it is currently challenging to retrieve all the necessary information for QC codes based exclusively on the available structural data,especially for transition metal *** overcome this limitation,we present cell2mol,a software that interprets crystallographic data and retrieves the connectivity and total charge of molecules,including the oxidation state(OS)of metal *** demonstrate that cell2mol outperforms other popular methods at assigning the metal OS,while offering a comprehensive interpretation of the unit *** code is made available,as well as reliable QC-ready databases totaling 31k transition metal complexes and 13k ligands that contain incomparable chemical diversity.

关键词： offering overcome properly

Control of light scattering by nanoparticles with optically-induced magnetic responses

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Chinese Physics B 2014年第4期23卷 41-51页

作者：刘伟 Andrey E. Miroshnichenko yuri S. Kivshar College of Optoelectronic Science and Engineering National University of Defence Technology Nonlinear Physics Center and Center for Ultrahigh-bandwidth Devices for Optical Systems CUDOS) Research School of Physics and EngineeringAustralian National University

Conventional approaches to control and shape the scattering pattems of light generated by different nanostructures are mostly based on engineering of their electric response due to the fact that most metallic nanostructures support only electric resonances in the optical frequency range. Recently, fuelled by the fast development in the fields of metamaterials and plasmonics, artificial optically-induced magnetic responses have been demonstrated for various nanostructures. This kind of response can be employed to provide an extra degree of freedom for the efficient control and shaping of the scattering patterns of nanoparticles and nanoantennas. Here we review the recent progress in this research direction of nanoparticle scattering shaping and control through the interference of both electric and optically-induced magnetic responses. we discuss the magnetic resonances supported by various structures in different spectral regimes, and then summarize the original results on the scattering shaping involving both electric and magnetic responses, based on the interference of both spectrally separated （with different resonant wavelengths） and overlapped dipoles （with the same resonant wavelength）, and also other higher-order modes. Finally, we discuss the scattering control utilizing Fano resonances associated with the magnetic responses.

关键词： optically-induced magnetic response scattering control Mie resonance Fano resonance

The Immersed Boundary Method: Application to Two-Phase Immiscible Flows

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Communications in Computational Physics 2019年第1期25卷 107-134页

作者： Avihai Spizzichino Sharone Goldring yuri Feldman Department of Mechanical Engineering Ben-Gurion University of the NegevP.O.Box 653Beer-Sheva 84105Israel Nonlinear Optics Group-Soreq NRC 81800 YavneIsrael

In this paper we present an extended formulation of the immersed boundary(IB)method that facilitates simulation of incompressible immiscible two-phase *** the developed formulation the pressure field and the surface tension forces associated with interface curvature are implicitly introduced in the form of distributed Lagrange *** approach provides for impermeability between both phases and exhibits accurate mass conservation without the need for additional correction ***,we present a grid independence study and extensive verification of the developed method for representative 2D two-phase flows dominated by buoyancy,shear stress,and surface tension forces.

关键词： Immersed boundary method two-phase immiscible flow distributed Lagrange mul-tiplier

Impulse controls in optimal harvesting of age-structured populations

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International Journal of Biomathematics 2023年第7期16卷 197-218页

作者： Natali Hritonenko Nobuyuki Kato yuri Yatsenko Department of Mathematics Prairie View A&M University PrairieViewTX77446USA Faculty of Electrical and Computer Engineering Kanazawa University Kanazawa920-1192Japan Dunham College of Business Houston Baptist University 7502FondrenHouston TX 77074USA

A nonlinear optimal control problem in the Lotka-McKendrick population model is *** describes rational management of age-structured farmed populations in aquaculture and indoor *** generalized functions,we prove the impulse nature of optimal *** analytic solutions for sustainable harvesting strategies are obtained and used to analyze the optimal dynamics of harvesting age and rotation under technological innovations.

关键词： Age-structured populations aquaculture optimal harvesting relaxed optimal controls Dirac measure