检索结果-南通市图书馆

Incubation time approach in rock fracture dynamics

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

SIMULATION MODEL OF TECHNOLOGICAL MINErAL DrESSING PrOCESSES

在线全文

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific Computing 2012年第3期3卷 36-42页

作者： NGUYEN vAN CHI A.v.petrov Department of Automated Systems Irkutsk State Technical University Lermontova 83 Irkutsk664074Russian Federation

The authors worked out a simulation model of technological mineral dressing processes,in which two simulations of technological mineral dressing processes methods are used:transformed structural graph method and method of separation *** first method makes it possible to simulate technological mineral dressing processes at the design stage in conditions of feedstock,equipment and control information *** second method is an effective instrument for operating plant simulation at the reengineering *** and economic efficiency evaluations of the mineral dressing plant are appended to the model.

关键词： Simulation mineral dressing structural graph separation characteristics reengineering efficiency

Magnetic and XPS studies of lithium lanthanide tetraphosphates LiLnP_4O_(12)(Ln=Nd,Gd,Er)

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of rare Earths 2013年第5期31卷 485-489页

作者： D.petrov B.Angelov v.Lovchinov Department of Physical Chemistry Plovdiv University"Paisii Hilendarski" 24 Tsar Asen Str. 4000 Plovdiv Bulgaria Department of Inorganic and Physical Chemistry University of Food Technologies-Plovdiv26 Maritsa Blvd. 4002 Plovdiv Bulgaria Institute of Solid State Physics Bulgarian Academy of Sciences72Tsarigradsko Chaussee Blvd.1784 SofiaBulgaria

Magnetic susceptibilities of flux-grown single crystals of LitnP4012 （Ln=Nd, Gd, Er） were measured in the temperature range of 2-300 K. The compounds were paramagnetic, and obeyed the Curie-Weiss law in the entire temperature interval, without magnetic phase transitions, and with effective magnetic moments close to those of the corresponding free Ln3＋ ions. X-ray photoelec- tron spectroscopy was applied to determine the positions of core-level electrons relative to the Fermi level： Li is; Ln 4f, 5p, 5s, 4d, 3d; P 2s, 2p; O 1s, 2s. The binding energies in these compounds were found slightly shifted compared to the respective values of the same elements.

关键词： lithium lanthanide tetraphosphates single crystals magnetic properties XPS spectroscopy rare earths

Energy of a solid sphere under nonstationary oscillations

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2014年第3期57卷 469-476页

作者： petrov Yu. SMIrNOv v. UTKIN A. BrATOv v. St.-Petersburg State University Institute of Problems of Mechanical Engineering Russian Academy of Sciences St.-Petersburg State Transport University

Analytical solution for spherically symmetric nonstationary oscillations of acoustic and elastic solid sphere is *** dependence of potential,kinetic and internal energy of a solid sphere is *** received results are of practical importance for a wide range of problems connected to testing of material dynamic strength parameters and to the problems of optimizing(minimizing)energy needed for fracture of solids.

关键词： nonstationary oscillations analytical solution material dynamics dynamic elastisity kinetic energy potential energy internal energy energy exchange

Ambiguity of Polystyrene Aerosol Beads Properties Found with Mie Spectra Analysis

在线全文

学校读者我要写书评

暂无评论

光谱学与光谱分析 2020年第1期40卷 324-327页

作者： petrov D v Zhuzhulina E A Crimean Astrophysical Observatory(CrAO rAS)

Broadband Mie scattering is used to determine the parameters of polystyrene aerosol beads in air,such as size and wavelength dependence of refractive *** method consists in the selection of such parameters of the scattering object,which reproduce observed spectrum *** is why it is very sensitive and hence very *** found that there is an ambiguity of polystyrene aerosol beads properties,determined with this *** combinations of polystyrene particle size and its refractive index can give the same position of Mie *** ambiguity leads to an increase in the error in determining the size and refractive index of the *** refined errors are calculated and the way of their reduction is indicated.

关键词： Nanomaterials Mie theory Polystyrene beads Size refractive index

Spectral Dependence of Quasi-rayleigh Polarization Leap of Nonspherical Particles:Polystyrene Beads Application

在线全文

学校读者我要写书评

暂无评论

光谱学与光谱分析 2021年第2期41卷 654-657页

作者： petrov D v Zhuzhulina E A Crimean Astrophysical Observatory(CrAO rAS) 298409 Nauch nyjRussia

Solid particles in Earth’s atmosphere,such as polystyrene beads,are an important factor affecting the processes of absorption and scattering of light in the *** processes affect on the solar energy transfer in the Earth’s atmosphere,consequently they have influence on the regional and global climate changes and atmospheric *** particular,great interest to study the scattering properties of small particles compared with wavelength,because of such particles experience low gravitational settlement and may have long time of life in the *** scattering particle is much smaller than the wavelength of the scattered or absorbed light,this is the case of rayleigh *** properties of these particles(such as intensity and the degree of linear polarization)at the rayleigh scattering are simply derived from electromagnetic Maxwell’s *** when the particles are large enough to be comparable with the wavelength,the deviations from rayleigh scattering law are *** of the clear manifestations of such deviations is the recently discovered quasi-rayleigh polarization leap of monodisperse spherical *** quasi-rayleigh polarization leap allows remote sensing of the sizes of distant particles,based on the spectral position of quasi-rayleigh polarization leap at different phase angles of *** this paper,we studied the effect of the non-sphericity of a scattering polystyrene particle on the magnitude and position of the quasi-rayleigh polarization *** is established that the non-sphericity shifts the position of the quasi-rayleigh polarization leap shorter *** is shown that for non-sphericity of particles makes the quasi-rayleigh polarization leap becomes less ***,it was found,that increasing of the phase angle and degree of non-sphericity shift the quasi-rayleigh polarization leap position to shorter ***,in the case of not very elongated particles,the quasi-

关键词： Nanomaterials Polarization T-matrix Quasi-rayleigh polarization leap

Diclofenac sodium aqueous systems at low concentrations: Interconnection between physicochemical properties and action on hydrobionts

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2020年第2期32卷 177-186页

作者： Irina S.ryzhkina Yuliya v.Kiseleva Lyaisan I.Murtazina Tatyana v.Kuznetsova Erik r.Zainulgabidinov Igor v.Knyazev Andrew M.petrov Sergey E.Kondakov Alexander I.Konovalov Arbuzov Institute of Organic and Physical Chemistry FRC Kazan Scientific CenterRussian Academy of Sciences8 Arbuzov str.Kazan 420088Russia Institute for Problems of Ecology and Mineral Wealth Use of Tatarstan Academy of Sciences 28 Daurskaya Str.Kazan 420087Russia Lomonosov Moscow State University Chemistry Dept.1/3 Lenin HillsMoscow 119899Russia

Diclofenac sodium(DS) is a widely used nonsteroidal anti-inflammatory drug(NSAIDs).NSAIDs are poorly removed during standard wastewater *** consequences of the presence of NSAIDs in rivers and lakes at 10-11–10-8 mol/L are not yet established;therefore, ecotoxicologists have focused their efforts on studying the effect of lowconcentration NSAIDs on fish and hydrobionts, and also on predicting the potential risks to *** provides some information about the bioeffects of some NSAID solutions in low concentrations but there is no physicochemical explanation for these *** the physicochemical patterns of DS solutions in the low range of concentrations and establishing an interconnection between the solutions’ physicochemical properties and bioeffects can provide a conceptually new and important source of information regarding the unknown effects of *** physicochemical properties and action of DS solutions on Ceriodaphnia affinis cladocerans,Paramecium caudatum infusoria, Chlorella vulgaris unicellular green algae, as well as on the growth of the roots of Triticum vulgare wheat seeds, were studied in the calculated concentration range of 1 × 10-3–1 × 10-18 mol/*** relationship between these phenomena was established using the certified procedures for monitoring the toxicity of natural water and *** was shown for the first time that water solutions of DS are dispersed systems in which the dispersed phase undergoes a rearrangement with dilution, accompanied by changes in its size and properties, which affects the nonmonotonic dependences of the system’s physicochemical properties and could cause nonmonotonic changes in action on hydrobionts in the low concentration range.

关键词： Diclofenac sodium Low concentration Aqueous solutions Physicochemical properties Hydrobionts Toxicity

Post-pancreatitis diabetes mellitus and excess intra-pancreatic fat deposition as harbingers of pancreatic cancer

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2021年第17期27卷 1936-1942页

作者： Maxim S petrov School of Medicine The University of AucklandAuckland 1142New Zealand

Progress in the fight against pancreatic cancer has been hampered by many *** of them is the inability to detect the disease early in overwhelming majority of *** present paper outlines a novel way in which progress could be *** includes a focus on two harbingers—post-pancreatitis diabetes mellitus and excess intra-pancreatic fat deposition—that converge at affecting the tumor macroenvironment and microenvironment specifically in the pancreas,not other *** two entities have the potential to be incorporated into future screening strategies with a view to early detecting of pancreatic cancer.

关键词： Pancreatic cancer Post-pancreatitis diabetes mellitus Intra-pancreatic fat Pancreatitis Early detection Screening

Development of Zeff diagnostic system on the Globus-M（M2） tokamak and the first experimental results

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2019年第10期21卷 33-39页

作者： E A TUKHMENEvA S Yu TOLSTYAKOv G S KUrSKIEv v K GUSEv v B MINAEv Yu v petrov N v SAKHArOv A Yu TELNOvA N N BAKHArEv P B SHEGOLEv E O KISELEv Ioffe Institute

Studying the behavior of effective ion charge Zeff, which indicates the degree of pollution of plasma and can provide valuable information about many processes taking place in plasma, mechanisms of the releasing impurities, transport, etc is of great interest. This paper describes the development of the Zeff diagnostic system for the Globus-M2 tokamak. The effective ion charge is determined on the basis of measurements of the bremsstrahlung intensity and Thomson scattering data-Te and ne profiles. The results of the first Zeff measurements obtained for several discharges on the Globus-M tokamak are presented in this paper. The results have been validated by simulation using the ASTrA transport code for the same discharges, and it has demonstrated a good agreement with the experimental results.

关键词： tokamak effective ion charge magnetic confinement