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On the Set of grouplikes of a Coring

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Acta Mathematica Sinica,English Series 2012年第1期28卷 195-204页

作者： L.EL KAOuTIT j.góMEZ-TORRECILLAS Departamento de lgebra.Facultad de Educación y Humanidades Universidad de GranadaEl Greco No 10E-51002 CeutaEspaa Departamento de lgebra.Facultad de Ciencias Universidad de GranadaE18071 GranadaEspaa

We focus our attention to the set gr（ξ） of grouplike elements of a coring ξover a ring A. We do some observations on the actions of the groups u（A） and Aut（ξ~） of units of A and of automorphisms of corings of ξ, respectively, on gr（ξ）, and on the subset gal（ξ）of all galois grouplike elements. Among them, we give conditions on ξ under which gal（ξ） is a group, in such a way that there is an exact sequence of groups u → u（Ag） → u（A） → gal（ξ） → u, where Ag is the subalgebra of coinvaxiants for some g ∈ gal（ξ）.

关键词： galois corings division ring extensions non-abelian cohomology

Delamination Testing of AlSi10Mg Sandwich Structures with Pyramidal Lattice Truss Core made by Laser Powder Bed Fusion

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Chinese journal of Mechanical Engineering 2021年第6期34卷 51-62页

作者： M.Nuño j.Bühring M.N.Rao K.-u.Schröder Institute of Structural Mechanics and Lightweight Design RWTH Aachen UniversityWüllnerstraβe 752072 AachenGermany

Sandwich structures possess a high bending stiffness compared to monolithic structures with a similar *** makes them very suitable for lightweight applications,where high stiffness to weight ratios are *** common manufacturing methods of sandwich structures involve adhesive bonding of the core material with the ***,adhesive bonding is prone to delamination,a failure mode that is often difficult to *** paper presents the results of delamination testing of fully additive manufactured(AM)AlSi10Mg sandwich structures with pyramidal lattice truss core using Laser Powder Bed Fusion(LPBF).The faces and struts are 0.5 mm thick,while the core is 2 mm *** inclination of the struts is 45°.To characterise the bonding strength,climbing drum peel tests and out-of-plane tensile tests are *** formulas are derived to predict the expected failure loads and *** analytics and tests are supported by finite element(FE)*** the analytic approach,design guidelines to avoid delamination in AM sandwich structures are *** study presents a critical face sheet thickness to strut diameter ratio for which the structure can *** ratio is mainly influenced by the inclination of the *** peel tests resulted in face yielding,which can also be inferred from the analytics and *** out-of-plane tensile tests didn’t damage the structure.

关键词： Additive Manufacturing Sandwich Structures Pyramidal Lattice Core

Acoustic Measurements for Determination of the Materials Damping using A Sound Source Localisation System

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Acta Metallurgica Sinica(English Letters) 2013年第2期26卷 113-121页

作者： j. gken j. Swiostek H. Hurdelbrink u. Keil Faculty of Maritime Studies University of Applied Sciences Emden/Leer Bergmannstr. 36 26789 LeerGermany Stalomax TM Company of High-Precision Mechanics ul. Parkingowa 45 37450 Stalowa WolaPoland

Noise measurements are especially a problem when the object under investigation is largely dimensioned and can only be measured from the distance. To obtain information about the location of noise generation, a measurement technique which makes sound visible in order to introduce further specific technical measures is advantageous. The question is if the time dependence of the signal got from such a non touching and non destructive acoustic method has the potential to calculate the materials damping from. using a small sound source localization system （Microflown^TM probe）, specimens of magnesium alloys with different grain sizes obtained by hydrostatic extrusion were investigated. It has been demonstrated that the fine grained microstructure led to a lower damping and its dependence on the strain was reduced. In this context, acoustic measurements by a sound source localisation system which makes materials characterization possible could be used as a quality tool to detect changes in highly stressed components. This approach allows to promote a selective substitution of conventional materials by more innovative ones. The offshore sector is considered to be a field of application： Wind turbines produce noise emission which stems mainly from turbulences at the tips of the rotor blades and vibrations of components inside the nacelle （e.9. gearbox, generator, ...）. If the vibration amplitudes are too high, microcracks of components can lead to failure over the long term. The monitoring of microstructural changes using a larger type of a sound source localisation system is considered as an innovative technical approach with respect to maintenance activities.

关键词： Magnesium Noise measurements MicroflownTM Damping

Magnetohydrodynamics with Implicit Plasma Simulation

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Communications in Computational Physics 2008年第8期4卷 433-456页

作者： j.u.Brackbill g.Lapenta Los Alamos National Laboratory(retired) Los AlamosNM 87544USA Centrum voor Plasma-Astrofysica DepartementWiskundeKatholieke Universiteit LeuvenCelestijnenlaan 200B3001 LeuvenBelgium

We considerwhether implicit simulation techniques can be extended in time and space scales to magnetohydrodynamics without any change but the addition of *** goal is to couple fluid and kinetic models together for application to multi-scale *** a simulation framework,transition from one model to the other would occur not by a change of algorithm,but by a change of *** would greatly simplify the *** the way,we have found new ways to impose consistent boundary conditions for the field solver that result in charge and energy conservation,and establish that numerically-generated stochastic heating is the problem to *** an MHD-like problem,collisions are clearly necessary to reduce the stochastic *** collisions,the heating rate is *** collisions,the heating rate is significantly reduced.

关键词： Plasma simulation MHD particle-in-cell implicit methods

Study on Ship Automatic Berthing System with Mooring Lines

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China Ocean Engineering 2017年第1期31卷 19-29页

作者： K.u.Yang j.g.Hur M.S.Choi D.j.Yeo j.H.Byun Department of Power System Engineering Chonnam National UniversityYeosu 550-749Korea College of Fisheries and Ocean Science Chonnam National UniversityYeosu 550-749Korea Departrnent of Maritime Police Science Chonnam National UniversityYeosu 550-749Korea

This study describes an automatic berthing system with mooring lines. It is designed to be berthed by using mooring device on the upper deck of a ship. It is to berth once maintaining parallel with the quay by controlling both forward and aft breast lines. Berthing method is used through length adjustment of mooring lines connected between ship and quay by controlling the angular velocity and the torque of hydraulic motor in mooring device. The study is conducted under three changing conditions of draft, such as even-keel, rise of the gravity center and trim to stern. Variables affecting berthing stability are determined based on the control performance of each condition. Bond graphs method is used to model the system. Controller is designed as PID control method of reference-model algorithm. The control program is composed of synchronous control system based on the equations derived with the numerical analysis. The tank test is conducted to verify the usefulness of the control program.

关键词： hydraulic maintain affecting berth torque adjustment draft attitude gravity verify

Slip flow of MHD Casson fluid in an inclined channel with variable transport properties

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Communications in Theoretical Physics 2020年第9期72卷 21-38页

作者： K V Prasad Hanumesh Vaidya C Rajashekhar Sami ullah Khan g Manjunatha j u Viharika Department of Mathematics Vijayanagara Sri Krishnadevaraya UniversityVinayaka NagarBallari-583105KarnatakaIndia Bhaskaracharya Study Chair Karnataka State Akkamahadevi Women's UniversityVijayapuraKarnatakaIndia Department of Mathematics COMSTAS University IslamabadSahiwal Campus 54000Pakistan Department of Mathematics Manipal Institute of TechnologyManipal Academy of Higher EducationManipalKarnataka576104-India

Due to the instructive role of the peristaltic phenomenon in the human body, interests have been developed in recent years towards peristaltic transport with various thermo-physical *** current investigation reveals the effects of the magnetic field and variable transport properties on the peristaltic transport of a Casson fluid slip flow through an inclined *** coupled partial differential equations regulate the fluid flow. Through the perturbation method, the momentum and energy equations are solved for small values of variable viscosity and thermal conductivity, and the closed-form solution is obtained for mass transfer. The impact on physiological quantities of related parameters of interest is evaluated and discussed via graphs. The results obtained for the current flow represent some interesting behaviors which have applications in the biomedical field.

关键词： velocity slip thermal slip concentration slip variable viscosity yield stress

Superstatistics of Modified Rosen-Morse Potential with Dirac Delta and uniform Distributions

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Communications in Theoretical Physics 2019年第10期71卷 1246-1252页

作者： u.S.Okorie A.N.Ikot g.j.Rampho R.Sever Department of Physics AkwaIbom State UniversityIkotAkpadenUyo.Nigeria Department of Physics University of Port HarcourtChobaNigeria Department of Physics University of South AfricaFlorida Park1710South Africa Department of Physics Middle East Technical University06800AnkaraTurkey

We discuss the thermodynamic properties of a modified Rosen-Morse potential using the q-deformed superstatistics approaches. We obtain the partition function with the help of the generalized Boltzmann factor from the modified Dirac delta distribution and uniform distribution. Other thermodynamic function is obtained for the superstatistics of the two distributions considered. We also discuss our results graphically and obtain the ordinary statistical quantities when the deformation parameter tends to zero.

关键词： superstatistics partition function thermodynamic function

Instantaneous frequency and wave mode identification in a magnetosheath using few spatial points

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Chinese Physics B 2013年第8期22卷 496-501页

作者： Nathaniel E u Beloff N george N j Department of Physics Akwa Ibom State UniversityNigeria university of Sussex Brighton UK

Observational data such as those obtained from the magnetosheath in the downstream of Earth＇s bow shock have waveforms that differ from those of sinusoidal signals. In practice, they are not even aggregates of sinusoidal signals. Therefore, the frequency decomposition for the data requires technique that will account for the time-varying features of the data that will lead to deduction of physical meaning of the observations. The combination of empirical mode decompo- sition （EMD） and Hilbert transform has been used for extracting the various contributing oscillatory modes （EMDs） and the instantaneous frequency determination （Hilbert transform） of every physically meaningful mode called intrinsic mode func- tion （IMF）. The resulting instantaneous frequencies are used to determine instantaneous wave vectors. The combination of the instantaneous frequencies and wave vectors is useful in the identification of wave modes based on the characteristics of the waves. The results show that EMD-Hilbert can be more reliable than simple Hilbert transform alone.

关键词： EMD-Hilbert transform instantaneous frequency and wave vector

Inter-relationship of Various Results in Analysis of （14.0 MeV／u） Pb＋Pb Reaction using Mica and CN-85 Track Detectors

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Chinese Physics Letters 2005年第1期22卷 69-71页

作者： F.N.Khattak E.u.Khan TabassumNasir j.j.Baluch F.u.Khan u.W.C. GomalUniversityDeraIsmailKhanPakistan RadiationPhysicsDivision PINSTECHNiloreIslamabadPakistan DepartmentofPhysics GomalUniversityDeraIsmailKhanPakistan

Two detector materials mica and cellulose-nitrate(CN)-85 have been used to study (14.0MeV/u) Pb + Pb reaction. Events of different multiplicities were registered in mica and CN-85 detectors using the 2π-geometry technique of solid state nuclear track detection. After removing the target material from the detectors the damaged trails in the detectors were revealed as tracks by proper chemical etching. The irradiated area of each sample was scanned and events of different multiplicities were traced. The binary events were bifurcated into elastic and inelastic events. The elastic binary events and three prong events, observed in the reaction, have been used to search out coefficients Cμν in the presence of both the detectors, for the reaction under study. using these coefficients 3- and 4-prong events have been analysed. From the detailed analysis of the results of (14.0MeV/u) Pb+Pb reaction, obtained from mica and CN-85 track detectors we observed a great resemblance of results obtained from the two detectors. Combining the results of both the detectors, we report some important outcomes.

关键词： CN-85轨迹探测器高能物理学铅原子碰撞反应固态