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Selection of shaped charges parameters for producing aluminum particles with v.locities in the range of 2.5-16 km/s

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Defence Technology（防务技术） 2024年第8期38卷 126-135页

作者： v.adimir I.Kolpakov.Sergey v.fedorov Ekaterina P.v.nogradov. Irina A.Bolotina Bauman Moscow State Technical Univ.rsity Moscow 105005Russia

Testing rocket and space technology objects in ground conditions for resistance to the impact of meteoroids and fragments of space debris can be carried out using shaped charges. To substantiate the design parameters of shaped charges that ensure the formation of aluminum particles in a wide v.locity range(from 2.5 to 16 km/s), numerical modeling of the formation process was carried out within the framework of a two-dimensional axisymmetric problem of continuum mechanics using three different computing codes to increase the reliability of the results. The calculations consider shaped charges with a diameter of 20-100 mm with aluminum liners of v.rious shapes. It is shown that the formation of particles with v.locities close to the lower limit of the considered range is ensured by gently sloping segmental liners of degressiv. thickness. To form higher-v.locity particles with v.locities ov.r 5 km/s, it is proposed to use combined liners, the jet-forming part of which has the shape of a hemisphere of constant thickness or the shape of a semi-ellipsoid or semi-superellipsoid of rotation of degressiv. thickness.

关键词： Space debris Meteoric impact Explosion Shaped charge High-v.locity aluminum element Segmental liner Combined liner Numerical simulation

Measurement of yields and angular distributions ofγ-quanta from the interaction of 14.1 Mev.neutrons with oxygen,phosphorus,and sulfur

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Chinese Physics C 2024年第3期48卷 79-92页

作者： D.N.Grozdanov.N.A.fedorov S.B.Dabylov. Yu.N.Kopatch I.N.Ruskov.v.R.Skoy T.Yu.Tretyakov. C.Hramco P.I.Kharlamov.G.v.Pampushik P.G.Filonchik A.v.Andreev Joint Institute for Nuclear Research(JINR) DubnaRussia Institute for Nuclear Research and Nuclear Energy Bulgarian Academy of SciencesSofiaBulgaria Faculty of Physics Lomonosov Moscow State UniversityMoscowRussia L.N.Gumilyov.Eurasian National Univ.rsity AstanaKazakhstan Skobeltsyn Institute of Nuclear Physics Moscow State UniversityMoscowRussia Institute of Chemistry of Moldov. ChisinauRepublic of Moldova Moscow Institute of Physics and Technology MoscowRussia

A study of the inelastic scattering of neutrons with an energy of 14.1 Mev.on the nuclei of oxygen,phosphorus,and sulfur was performed at the TANGRA facility at JINR(Dubna).The experiment aimed to refine existing data and obtain new data on the yields and angular distributions ofγ-quanta emitted by the studied nuclei due to neutron-induced nuclear reactions using the tagged neutron *** types of detector systems were used to registerγ-***γ-ray yields were measured using a high-purity germanium(HPGe)*** angular distributions ofγ-rays were obtained using a system of 18 scintillation detectors based on bismuth germanite Bi_(4)Ge_(3)O_(12)(BGO)located around the *** performed experiments measured the yields of two transitions for the reaction of tagged neutrons with 16O,nine transitions for the reaction with ^(31)P,and nine transitions for the reaction with ^(32)S for the first *** angular anisotropy of theγ-radiation accompanying the inelastic scattering of neutrons with an energy of 14.1 Mev.on ^(31)P nuclei was also measured for the first time.

关键词： tagged neutron method yields of gamma-quanta high-resolution gamma-spectrometry neutron-nuclear reactions neutron scattering

生物炭/光催化复合材料去除水环境有机污染物研究进展

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化学试剂 2024年第5期46卷 53-62页

作者：周通任旭阳王晨阳李发站郭翔吴俊峰 fedorov Sv.atoslav.v 华北水利水电大学环境与市政工程学院河南郑州450040 河南城建学院河南省水体污染防治与修复重点实验室河南平顶山467036 圣彼得堡国立建筑工程大学环境与市政工程学院俄罗斯圣彼得堡190005

以光催化材料为基础的高级氧化处理技术被公认为是处理水环境中有机污染物最具潜力的绿色方法之一。同时,“以废治废”逐渐成为“碳中和”背景下对污染治理的新要求,为提高环境治理水平和社会可持续发展能力,利用生物废弃物等转化为生... 详细信息

以光催化材料为基础的高级氧化处理技术被公认为是处理水环境中有机污染物最具潜力的绿色方法之一。同时,“以废治废”逐渐成为“碳中和”背景下对污染治理的新要求,为提高环境治理水平和社会可持续发展能力,利用生物废弃物等转化为生物炭已成为当前研究热点。利用生物炭具有比表面积易调控、导电性能好以及表面官能团丰富等优势,将光催化氧化与生物炭吸附进行功能协同是一种极具发展前景的有机污染物去除研究体系。概括了生物炭/光催化复合材料的制备方法与工艺,分析了复合材料中生物炭和光催化材料二者功能间的相互影响。此外,通过阐述生物炭/光催化复合材料对污染物的去除过程,深入探讨了吸附-光降解的整体作用机制,并梳理了国内外针对最新重点管控新污染物清单的相关研究进展。最后针对复合材料界面关系、电子迁移性质、综合水体应用等方面,对生物炭/光催化复合材料提出了相关讨论和未来建议。

关键词：生物炭光催化吸附-降解机制新污染物碳中和

Acoustics of a v.scoelastic medium with encapsulated bubbles

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Journal of Hydrodynamics 2021年第1期33卷 55-62页

作者： Damir A.Gubaidullin Yuri v.fedorov Laboratory of Continuum Mechanics Institute of Mechanics and EngineeringFRC Kazan Scientific CenterRussian Academy of SciencesKazanRussia

In this paper,a modified Rayleigh-Lamb equation is deriv.d that takes into account the radial v.brations of a gas bubble coated with a v.scoelastic shell and located in an elastic *** small oscillations of inclusion,the problem of heat exchange between a gas,a liquid phase,a v.scoelastic shell,and an elastic medium is *** energy integral is *** the case of small disturbances,the dispersion relation is found from the Rayleigh-Lamb equations,energy,and the known wav. equation for the bubbly *** analytical expression of the equilibrium speed of sound is written out and its dependence on the size of the v.scoelastic shell and the disturbance frequency is *** example of a mixture of polydimethylsiloxane with air bubbles coated with a rubber shell illustrates the influence of the elasticity of the carrier medium and the shell of the bubbles on the dependence of the phase v.locity and attenuation coefficient on the perturbation *** a mixture of water with air bubbles coated with a rubber shell,the influence of the dependences of the shear modulus and v.scosity of butyl rubber on the frequency of disturbances at different temperature on the dispersion curv.s is shown.A comparison of the theory with experimental data is giv.n.

关键词： Acoustic wav. gas bubbles v.scoelastic medium and shell shear modulus dispersion equation

To the Solution of a Spherically Symmetric Problem of General Relativ.ty

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Journal of Modern Physics 2023年第2期14卷 147-159页

作者： v.lery v. v.siliev.leonid v. fedorov Russian Academy of Sciences Moscow Russia

The paper is dev.ted to the spherically symmetric problem of General Relativ.ty. Existing solutions obtained by K. Schwarzschild and v. Fock are presented and discussed. A special geometry of the Riemannian space induced by grav.tation is proposed. According to this geometry the four-dimensional Riemannian space is assumed to be Euclidean with respect to the space coordinates and Riemannian with respect to the time coordinate. The solution of the Einstein equations for the empty space with this geometry coincides with the solution in Gullstand-Painlev.r coordinates. In application to the found solution, the problem of the light trajectory dev.ation in the v.cinity of Sun and the problem of escape v.locity are discussed.

关键词： General Relativ.ty Spherically Symmetric Problem

Spherically Symmetric Problem of General Relativ.ty for an Elastic Solid Sphere

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Journal of Modern Physics 2023年第6期14卷 818-832页

作者： v.lery v. v.siliev.leonid v. fedorov Russian Academy of Sciences Moscow Russia

The paper is dev.ted to a spherically symmetric problem of General Relativ.ty (GR) for an elastic solid sphere. Originally dev.loped to describe grav.tation in continuum (v.cuum, gas, fluid and solid) GR does not prov.de the complete set of equations for solids and, in contrast to the Newton grav.tation theory, does not allow us to study the stresses induced by grav.tation in solids, because the compatibility equations which are attracted in the Euclidean space for this purpose do not exist in the Riemannian space. To solv. the problem within the framework of GR, a special geometry of the Riemannian space induced by grav.tation is proposed. According to this geometry, the four-dimensional Riemannian space is assumed to be Euclidean with respect to the space coordinates and Riemannian with respect to the time coordinate. Such interpretation of the Riemannian space in GR allows us to supplement the conserv.tion equations for the energy-momentum tensor with compatibility equations of the theory of elasticity and to arriv. to the complete set of equations for stresses. The analytical solution of the Einstein equations for the empty space surrounding the sphere and the numerical solution for the internal space inside the sphere with the proposed geometry are presented and discussed.

关键词： General Relativ.ty Spherically Symmetric Problem Elastic Sphere

Linearized Equations of General Relativ.ty and the Problem of Reduction to the Newton Theory

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Journal of Modern Physics 2020年第2期11卷 221-236页

作者： v.lery v. v.siliev.leonid v. fedorov Institute of Problems in Mechanics Russian Academy of Sciences Moscow Russia

The paper is concerned with the problem of reduction of the general relativ.ty theory to the Newton grav.tation theory for a grav.tation field with relativ.ly low intensity. This problem is traditionally solv.d on the basis of linearized equations of general relativ.ty which, being matched to the Newton theory equations, allow us to link the classical grav.tation constant with the constant entering the general relativ.ty equations. Analysis of the linearized general relativ.ty equations shows that it can be done only for empty space in which the energy tensor is zero. In solids, the set of linearized general relativ.ty equations is not consistent and is not reduced to the Newton theory equations. Specific features of the problem are demonstrated with the spherically symmetric static problem of general relativ.ty which has the closed-form solution.

关键词： General Relativ.ty Grav.tation Constant Linearized Equations Spherically Symmetric Problem

To the Schwarzschild Solution in General Relativ.ty

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Journal of Modern Physics 2018年第14期9卷 2482-2494页

作者： v.lery v. v.siliev.leonid v. fedorov Institute of Problems in Mechanics Russian Academy of Sciences Moscow Russia

The paper is concerned with the history of the spherically symmetric static problem solution of General Relativ.ty found in 1916 by K. Schwarzschild [1] [2] which is interpreted in modern physics as the background of the objects referred to as Black Holes. First, the modern interpretation this solution which does not exactly coincide with original solution obtained by K. Schwarzschild is discussed. Second, the basic equations of the original Schwarzschild solution are presented in modern notations allowing us to compare existing and original solutions. Finally, a modification of the Schwarzschild approach is proposed allowing us to arriv. at the exact solution of the Schwarzschild problem.

关键词： General Relativ.ty Spherically Symmetric Problem Schwarzschild’s Solution Black Holes

To the Complete Set of Equations for a Static Problem of General Relativ.ty

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Journal of Modern Physics 2019年第12期10卷 1401-1415页

作者： v.lery v. v.siliev.leonid v. fedorov Institute of Problems in Mechanics Russian Academy of Sciences Moscow Russia

The paper is concerned with the formulation of the static problem of general relativ.ty. As known, this problem is reduced to ten equations for the compo-nents of the Einstein tensor and the solution of these equations is associated with two principal problems. First, since the components of the Einstein tensor identically satisfy four conserv.tion equations, only six of these equations are mutually independent. So, the set of the Einstein equations actually contains six independent equations for ten components of the metric tensor and should be supplemented with four additional equations which are missing in the original theory. Second, for a deformable solid the Einstein tensor is associated with the energy tensor which is expressed in terms of six stresses induced by grav.tation. These stresses are not known and the relativ.ty theory does not propose any equations for them. Thus, the static problem of general relativ.ty cannot be properly formulated because the set of gov.rning equations is not complete. In the paper, the problem of completeness of the general relativ.ty gov.rning set of equations is analyzed in application to the spherically symmetric static problem and the proposed approach is further described for the general case. As an example, linearized axisymmetric problem is considered.

关键词： General Relativ.ty Coordinate Conditions Compatibility Stress Equations Spherically Symmetric Problem