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Analysis of Wire.v.bration in Wire electric Discharge Machining Process

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仪器仪表学报 2013年第S1期34卷 208-213页

作者： Andhare A.B Jithin e.v. Department of Mechanical engineering visve.v.raya National Institute of Technology

Wire electric discharge machining(WeDM)process is used for precision *** accuracy of machining is function of various parameters like current,voltage,wire speed,gap between wire and work piece,wire oscillation,work material,wire material,*** the process parameters are selected,it is important that the wire.v.brations are less to obtain a good surface *** to the importance of wire.v.bration in obtaining the surface finish,it is necessary to study the wire *** paper discusses different models of wire.v.bration presented in the literature and simulates a closed form solution of wire.v.bration using *** transverse.v.bration of wire is analysed as forced vibration of moving wire with excitation due to the sparks during *** resulting partial differential equation is solved by using finite difference method and vibration is also simulated in the finite element package‘ANSYS’.The wire behaviour is investigated under different operating conditions and results of the two methods are

关键词： Wire vibration Wire electric Discharge Machining Finite Difference Method Finite element Method

Combined method of plastic work piece machining based on a pretreatment mechanical down

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Rare Metals 2007年第S1期26卷 20-24页

作者： eReNKOv O Y kovalchuk S A GAvRILOvA A v Woodworking Department Institute of Information TechnologyPacific National University

An analysis of polymer materials behavior under cutting forces load was *** analysis was accomplished taking into account the existence and interaction of micro cracks in *** the basis of modeling representations of a polymeric material behavior at cutting the method of preliminary mechanical destruction a superficial layer of polymeric material was *** essence of the method consists in producing micro-cracks in form of blind holes on the upper layer of blanks before *** aim of this method is a plastic deformation zones creation under stresses interaction occurring at the adjacent crack *** of experimental researches of fabric-based laminate turning processing according to the offered method were *** analysis of the rece.v.d results confirms expediency of application of the given combined method and the decrease of a roughness on the processed surface of fabric-based laminate is testifying about it.

关键词： polymer materials microcracks surface roughness stresses distribution mechanical destruction deformation zones machining methods

Accounting for Quadratic and Cubic Invariants in Continuum Mechanics–An Ove.v.ew

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Fluid Dynamics & Materials Processing 2024年第9期20卷 1925-1939页

作者： Artur v.Dmitrenko vladislav M.Ovsyannikov Department of Physics National Research Nuclear University(MEPhI)Kashirskoye Shosse 31Moscow115409Russian Federation Department of Thermal engineering and Department of Waterways Ports and Hydraulic StructuresRussian University of Transport(MIIT)Obraztsova Street 9Moscow127994Russian Federation

The differential equations of continuum mechanics are the basis of an uncountable.v.riety of phenomena and technological processes in fluid-dynamics and related *** equations contain derivatives of the first order with respect to *** derivation of the equations of continuum mechanics uses the limit transitions of the tendency of the.v.lume increment and the time increment to *** are used to derive the wave *** differential wave equation is second order in ***,increments of volume and increments of time in continuum mechanics should be considered as small but finite quantities for problems of wave *** is important for calculating the generation of sound waves and water hammer ***,the euler continuity equation with finite time increments is of *** finiteness of the time increment makes it possible to take into account the quadratic and cubic invariants of the strain rate *** is a new branch in *** and cubic invariants will be used in differential wave equations of the second and third order in time.

关键词： Quadratic invariant cubic invariant continuity equation generation of periodic waves N.e.Zhukovsky’s hydraulic shock turbulence

Myelin histology:a key tool in ne.v.us system research

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Neural Regeneration Research 2024年第2期19卷 277-281页

作者： Óscar Darío García-García víctor Carriel Jesús Chato-Astrain Department of Histology Tissue Engineering GroupUniversity of Granada&Instituto de Investigación Biosanitaria ibs.GRANADAGranadaSpain

The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated ne.v. *** to the complex structure and composition of myelin,various histological techniques have been developed over the centuries to evaluate myelin under normal,pathological or experimental ***,methods to assess myelin integrity or content are key tools in both clinical diagnosis and neuroscience *** this review,we provide an updated summary of the composition and structure of the myelin sheath and discuss some histological procedures,from tissue fixation and processing techniques to the most used and practical myelin histological staining *** the lipoprotein nature of myelin,the main features and technical details of the different available methods that can be used to evaluate the lipid or protein components of myelin are described,as well as the precise ultrastructural techniques.

关键词： fluorescence microscopy histology light microscopy lipid histochemistry metallographic techniques myelin histochemistry myelin immunohistochemistry myelin structure&composition myelin ultrastructural evaluation tissue fixation&processing

SANC Monte Carlo programs for small-angle Bhabha scattering

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Chinese Physics C 2024年第4期48卷 14-19页

作者： A.B.Arbuzov S.G.Bondarenko I.R.Boyko L.v.Kalinovskaya A.A.Kampf R.R.Sadykov v.L.Yermolchyk Bogoliubov Laboratory of Theoretical Physics JINRDubna141980 Russia Dzhelepov Laboratory of Nuclear Problems JINRDubna141980 Russia Dubna State University Dubna141982 Russia

Luminosity monitoring at e^(+)e^(−)colliders was investigated using SANC Monte Carlo event generator ReneSANCe and integrator MCSANC for simulation of Bhabha scattering at low *** are presented for center-of-mass energies of the Z boson resonance and at 240 Gev for the conditions of typical luminosity *** is shown that bremsstrahlung events with extremely low electron scattering angles are relevant to match the precision tags of future electron-positron colliders.

关键词： luminosity Bhabha scattering QeD Monte Carlo simulation

Underestimated seismic hazard in the south of the Issyk-Kul Lake region (northern Tian Shan)

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Geodesy and Geodynamics 2017年第3期8卷 169-180页

作者： A.M. Korzhenkov e.v. Deev O.Yu. Schmidr Institute of Physics of the earth. Russian Academy of Sciences Moscow Russia b.n.yeltsyn Kyrgyz-Russian Slavic University Kievskaya Str 44. Bishkek. Kyrgyzstan A.A. Trofimuk Institute of Petroleum Geology and Geophysics Siberian Branch of the Russian Academy of Sciences Novosibirsk Russia Novosibirsk State University Novosibirsk Russia

The Tian Shan Mountains were formed in the result of the India-eurasia collision, which leads to cre- ation of contrast high-mountain relief and world known seismic activity. The seismic catastrophes, recorded instrumentally, have occurred to the north of the Issyk-Kul Lake region. There are also known significant earthquakes with magnitude being about 7 in western and eastern parts of the mentioned lake region. Only in the south of the Issyk-Kul depression the strong earthquakes recorded by the seismic network were not known. Our recent study in the south of the lssyk-Kul Lake region has revealed numerous active tectonic structures related to South Issyk-I（ul Fault： faults and folds, responsible for strong earthquakes＇ occurrence. These were historical and paleoseismic defornlations which led to changes in relief： fault scarps and significant rockslides. We have also found spectacular deformations in archeological monuments. All these deformations testify the location of epicentral areas of two strong historic （about llth and 16th （？） centuries AD） and paleoearthquakes （Holocene and Late Pleistocene）. Magnitude of ancient seismic events, according to parameters of the revealed fault scarps, were Ms 〉 7 and seismic intensity I 〉 IX. All revealed seismic deformations are located to adyrs （piedmonts） of the Terskey Ala-Too range bordered of the lssyk-Kul Lake depression in the south. Their formation is described by the model of a fault which rupture plane becomes shallower southward. This model is complicated by the presence of reverse thrusts. Here, we should admit the existence of a single zone of South lssyk-Kul Fault which is a long-lived feature which separates the structures with the different regime of movements during the Neotectonic time. All obtained data led us to a conclusion of significant underestimation of the seismic hazard in southern lssyk-Kul Lake region.

关键词： Paleoseismic deformations Fault scarps Trenching Kadzhi-Say river Tossor river lssyk-Kul Lake Tian Shau Seismic hazard assessment

Pulsed THz radiation under ultrafast optical discharge of vacuum photodiode

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Frontiers of Optoelectronics 2024年第2期 100-113页

作者： Aleksandr A.Ushakov Kseniia A.Mamaeva Leonid v.Seleznev Georgy e.Rizaev vladimir Bukin Timophey v.Dolmatov Pavel A.Chizhov vladimir Bagdasarov Sergey v.Garnov Prokhorov General Physics Institute of the Russian Academy of Sciences Physical Institute Russian Academy of Sciences Moscow Institute of Physics and Technology Russian Institute for Scientific and Technical Information

In this paper, we first present an experimental demonstration of terahertz radiation pulse generation with energy up to 5 pJ under the electron emission during ultrafast optical discharge of a vacuum photodiode. We use a femtosecond optical excitation of metallic copper photocathode for the generation of ultrashort electron bunch and up to 45 kv/cm external electric field for the photo-emitted electron acceleration. Measurements of terahertz pulses energy as a function of emitted charge density, incidence angle of optical radiation and applied electric field have been provided. Spectral and polarization characteristics of generated terahertz pulses have also been studied. The proposed semi-analytical model and simulations in COMSOL Multiphysics prove the experimental data and allow for the optimization of experimental conditions aimed at flexible control of radiation parameters.

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Older Adult Compendium of Physical Activities:energy costs of human activities in adults aged 60 and older

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Journal of Sport and Health Science 2024年第1期13卷 13-17,F0003页

作者： erik A.Willis Stephen D.Herrmann Mary Hastert Chelsea L.Kracht Tiago v.Barreira John M.Schuna Jr. Zhenghua Cai Minghui Quan Scott A.Conger Wendy J.Brown Barbara e.Ainsworth Center for Health Promotion and Disease Prevention University of North Carolina at Chapel HillChapel HillNC 27599USA Kansas Center for Metabolism and Obesity Research The University of Kansas Medical CenterKansas CityKS 66160USA Division of Physical Activity and Weight Management Department of Internal MedicineUniversity of Kansas Medical CenterKansas CityKS 66160USA Clinical Science Division Pennington Biomedical Research CenterBaton RougeLA 70808USA exercise Science Department Syracuse UniversitySyracuseNY 13244USA School of exercise&Sport Science Oregon State UniversityCorvallisOR 97331USA School of exercise and Health Shanghai University of SportShanghai 200438China Department of Kinesiology Boise State UniversityBoiseID 83725USA School of Human Movement and Nutrition Sciences The University of QueenslandSt.LuciaQLD 4072Australia Faculty of Health Sciences and Medicine Bond UniversityGold CoastQLD 4229Australia College of Health Solutions Arizona State UniversityPhoenixAZ 85003USA

Purpose:To describe the development of a Compendium for estimating the energy costs of activities in adults>60 years(OA Compendium).Methods:Physical activities(PAs)and their metabolic equivalent of task(MeT)values were obtained from a systematic search of studies published in 4 sport and exercise databases(PubMed,embase,SPORTDiscus(eBSCOhost),and Scopus)and a review of articles included in the 2011 Adult Compendium that measured PA in older *** values were computed as the oxygen cost(vO_(2),mL/kg/min)during PA divided by 2.7 m L/kg/min(MeT_(60+))to account for the lower resting metabolic rate in older ***:We identified 68 articles and extracted energy expenditure data on 427 *** these,we derived 99 unique Specific Activity codes with corresponding MeT_(60+)values for older *** developed a website to present the OA Compendium MeT_(60+)values:https://***:The OA Compendium uses data collected from adults>60 years for more accurate estimation of the energy cost of PAs in older *** is an accessible resource that will allow researchers,educators,and practitioners to find MeT_(60+)values for older adults for use in PA research and practice.

关键词： energy expenditure exercise MeT Older adults

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什么样的火山会“发火”

当代学生 2024年第1期 26-28页

作者： e.v 不详

地处北大西洋和北冰洋交汇处的冰岛,本就是一个地质活动频繁的国家,前不久更是曾进入了全国紧急状态,不少城镇的居民举家搬家,去往了更为安全的地方。究竞怎样的火山容易爆发?冰岛会不会成为下一个庞贝古城?只有了解火山的“脾气”,我... 详细信息

地处北大西洋和北冰洋交汇处的冰岛,本就是一个地质活动频繁的国家,前不久更是曾进入了全国紧急状态,不少城镇的居民举家搬家,去往了更为安全的地方。究竞怎样的火山容易爆发?冰岛会不会成为下一个庞贝古城?只有了解火山的“脾气”,我们才能知道它什么时候会“发火”。

关键词：庞贝古城北冰洋紧急状态北大西洋冰岛火山发火