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Structure of low-head two-phase flow in flat nozzlesduring outflow of the liquid into rarefied medium

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航空动力学报 2011年第10期26卷 2188-2192页

作者： Kochenkov A g Tonkonog V g Kazan State Technical University named after A. N. Tupolev Kazan Russian Federation

Outcomes of experimental researches of the low-pressure adiabatic flow of the boiling liquid through two-dimensional Laval nozzles in a vacuum atmosphere were *** of critical conditions of flow were *** forms of a stream were investigated and their connection with crisis of flow was *** was established periodic non-stationary macrostructures of a stream which was stipulated by the rotational gear of origin of a vapor phase.

关键词： component low-head flow flow structure flat nozzle rarefied medium the mechanizm of vaporization mass flow rate

Radiation force and torque on a two-dimensional circular cross-section of a non-viscous eccentric layered compressible cylinder in acoustical standing waves

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Chinese Physics B 2021年第2期30卷 355-366页

作者： F g Mitri Santa Fe NM 87508USA

The purpose of this study is to develop an analytical formalism and derive series expansions for the time-averaged force and torque exerted on a compound coated compressible liquid-like cylinder,insonified by acoustic standing waves having an arbitrary angle of incidence in the polar(transverse)*** host medium of wave propagation and the eccentric liquid-like cylinder are *** computations illustrate the theoretical analysis with particular emphases on the eccentricity of the cylinder,the angle of incidence and the dimensionless size parameters of the inner and coating cylindrical fluid *** method to derive the acoustical scattering,and radiation force and torque components conjointly uses modal matching with the addition theorem,which adequately account for the multiple wave interaction effects between the layer and core fluid *** results demonstrate that longitudinal and lateral radiation force components ***,an axial radiation torque component is quantified and computed for the non-absorptive compound cylinder,arising from geometrical asymmetry considerations as the eccentricity *** computational results reveal the emergence of neutral,positive,and negative radiation force and torque depending on the size parameter of the cylinder,the eccentricity,and the angle of incidence of the insonifying ***,based on the law of energy conservation applied to scattering,numerical verification is accomplished by computing the extinction/scattering energy *** results may find some related applications in fluid dynamics,particle trapping,mixing and manipulation using acoustical standing waves.

关键词： radiation force radiation torque liquid compound cylinder multiple scattering acoustical standing waves

Recent research in mechanical properties of geopolymer-based ultrahigh-performance concrete:A review

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Defence Technology（防务技术） 2024年第2期32卷 67-88页

作者： g.Murali Division of Research&Innovation Uttaranchal UniversityDehradun 248007India

Due to the growing need for sustainable and ultra-high-strength construction materials,scientists have created an innovative ultra-high-performance concrete called geopolymer based ultra-highperformance concrete(gUHPC).Besides,in the last few decades,there have been a lot of explosions and ballistic attacks around the world,which have killed many civilians and fighters in border *** this context,this article reviews the fresh state and mechanical properties of ***,the ingredients of gUHPC and fresh properties such as setting time and flowability are briefly ***,the review of compressive strength,flexure strength,tensile strength and modulus of elasticity of fibrous ***,the blast and projectile impact resistance performance was ***,the microstructural characteristics were reviewed using the scanning electron microscope and X-ray Powder *** review outcome reveals that the mechanical properties were increased when 30%silica fume was added to a higher dose of steel fibre to improve the microstructure of *** is hypothesized that the brittleness of gUHPC was mitigated by adding 1.5%steel fibre reinforcement,which played a role in the decrease of contact explosion cratering and *** the need for cement in gUHPC was a key factor in the review,indicating a promising potential for lowering carbon ***,gUHPC research is still in its early stages,so more study is required before its full potential can be utilized.

关键词： Mechanical properties Blast Projectile impact Fibre geopolymer Silica fume Alkaline activators

New method for rekindling the explosive waves in Maxwellian space plasmas

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Plasma Science and Technology 2020年第12期22卷 48-58页

作者： g C DAS Kalikadas Road Byelane HazraparaCoochbehar-736101West BengalIndia

Our interest is to study the nonlinear wave phenomena in complex plasma constituents with Maxwellian electrons and ions. The main aim is to use a new method known as the(g′/g)method to exhibit the effects of dust charge fluctuations on the evolution of nonlinear waves. The coherent features of the shock and solitary waves along with the generation of high-energy waves have been amplified through the solution of the Korteweg–de Vries–Burgers equation,and the different natures of the waves were found successfully. Results are discussed graphically with the thoughtful choice of typical plasma parameters from different space plasma environments, exactly those found in cosmic dusty plasmas laden in ionospheric auroral region,radial spokes of Saturn's rings, planetary nebulae and solar F-corona region. All conclusions are in good accordance with the actual occurrences and could be of interest to further investigations of space. Moreover, the applicability of the present method is hoped to be a great enhancement by its use as ingenious mechanism used to evaluate the soliton dynamics and Burgers shock waves.

关键词： Maxwellian complex plasma nonlinear waves soliton and shock propagation (g′/g)method space plasmas

Acoustic radiation force and torque on a lossless eccentric layered fluid cylinder

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Chinese Physics B 2020年第11期29卷 140-145页

作者： F g Mitri Santa Fe NM 87508USA

Exact analytical equations and computations for the longitudinal and transverse acoustic radiation force and axial torque components for a lossless eccentric liquid cylinder submerged in a nonviscous fluid and insonified by plane waves progressive waves(of arbitrary incidence in the polar plane)are established and computed *** modal matching method and the translational addition theorem in cylindrical coordinates are used to derive exact mathematical expressions applicable to any inner and outer cylinder sizes without any approximations,and taking into account the interaction effects between the waves propagating in the layer and those scattered from the cylindrical *** results show that longitudinal and transverse radiation force components arise,in addition to the emergence of an axial radiation torque component acting on the non-absorptive compound cylinder due to geometrical asymmetry as the eccentricity *** computations demonstrate that the axial torque component,which arises due to a geometrical asymmetry,can be positive(causing counterclockwise rotation in the polar plane),negative(clockwise rotation)or neutral(rotation cancellation)depending on the size parameter of the cylinder and the amount of ***,verification and validation of the results have been accomplished from the standpoint of energy conservation law applied to scattering,and based on the reciprocity theorem.

关键词： acoustic radiation force acoustic radiation torque non-viscous liquid eccentric cylinder

Nonlinear vibration analysis of laminated composite Mindlin micro/nano-plates resting on orthotropic Pasternak medium using DQM

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Applied Mathematics and Mechanics(English Edition) 2015年第8期36卷 1033-1044页

作者： A.g.ARANI g.S.JAFARI Faculty of Mechanical Engineering University of Kashan Institute of Nanoscience & Nanotechnology University of Kashan

The nonlocal nonlinear vibration analysis of embedded laminated micro- plates resting on an elastic matrix as an orthotropic Pasternak medium is investigated. The small size effects of micro/nano-plate are considered based on the Eringen nonlocal theory. Based on the orthotropic Mindlin plate theory along with the von Kármán geo- metric nonlinearity and Hamilton＇s principle, the governing equations are derived. The differential quadrature method （DQM） is applied for obtaining the nonlinear frequency of system. The effects of different parameters such as nonlocal parameters, elastic me- dia, aspect ratios, and boundary conditions are considered on the nonlinear vibration of the micro-plate. Results show that considering elastic medium increases the nonlinear frequency of system. F^lrthermore, the effect of boundary conditions becomes lower at higher nonlocal parameters.

关键词： nonlinear vibration laminated micro-plate orthotropic Pasternak medium,differential quadrature method

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基于非侵入式的事件检测方法统计评估

电测与仪表 2020年第1期57卷 106-112,120页

作者：张露 Francois auger 荆朝霞 Sarra Houidi Huu Kien Bui 肖江华南理工大学广州510640 法国南特大学法国南特44600

非侵入式负荷监测是负荷监测的重要发展方向,事件检测是非侵入式负荷监测的重点研究内容。多维信号相比一维信号可以提供多源信息,若信号不同维度间相关度大,则可以提高检测精度。文章基于统计假设首次推导BIC、CUSUM和gLRT三种算法的... 详细信息

非侵入式负荷监测是负荷监测的重要发展方向,事件检测是非侵入式负荷监测的重点研究内容。多维信号相比一维信号可以提供多源信息,若信号不同维度间相关度大,则可以提高检测精度。文章基于统计假设首次推导BIC、CUSUM和gLRT三种算法的决策函数,并以二维信号为例进行仿真实验,比较了三种算法的检测结果。仿真实验证明补充合适的第二维信号可以提高整体检测精度,且得到不同算法的适用条件,即CUSUM算法适用于高阈值检测,gLRT算法适用于低阈值检测。

关键词：非侵入式负荷监测事件检测二维信号决策函数统计评估

Quantum statistical properties of photon-added spin coherent states

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Chinese Physics B 2017年第11期26卷 206-209页

作者： g Honarasa Department of Physics Shiraz University of Technology

The photon-added spin coherent state as a new kind of coherent state has been defined by iterated actions of the proper raising operator on the ordinary spin coherent state. In this paper, the quantum statistical properties of photon-added spin coherent states such as photon number distribution, second-order correlation function and Wigner function are studied. It is found that the Wigner function shows the negativity in some regions and the second-order correlation function is less than unity. Therefore, the photon-added spin coherent state is a nonclassical state.

关键词： photon-added spin coherent states photon number distribution Wigner function

Dielectric behavior of Cu-Zn ferrites with Si additive

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Chinese Physics B 2014年第5期23卷 553-555页

作者： Uzma g Department of Physics University of Wah

Since ferrites are highly sensitive to the additives present in or added to them, extensive work, to improve the properties of basic ferrites, has been carded out on these aspects. The present paper reports the effects of composition, frequency, and temperature on the dielectric behavior of a series of CuxZn1-xFe2O4 ferdte samples prepared by the usual ceramic technique. In order to improve the properties of the samples, low cost Fe2O3 having 0.5 wt.% Si as an additive is selected to introduce into the system. The dielectric constant increases by increasing the Cu content, as the electron exchange of Cu^2＋〈=〉 Cu^＋ is responsible for the conduction and the polarization. However, the addition of Si could decrease the dielectric constant as it suppresses the ceramic grain growth and promotes the quality factor at higher frequencies. Dielectric constant ε′ and loss tangent tan δ of the mixed Cu-Zn ferrite decrease with increasing frequency, attributed to the Maxwell-Wagner polarization, which increases as the temperature increases.

关键词： Cu-Zn ferrite dielectric behavior Si additive