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Exploring the concept of castability in magnesium die-casting alloys

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journal of Magnesium and Alloys 2021年第1期9卷 102-111页

作者： j.P.Weiler Meridian Lightweight Technologies Canada

This paper provides a summary of the recent work completed and history of the measure of manufacturability in the magnesium diecasting *** most popular die-casting alloys utilized in this industry are based on the Mg-Al system,including AZ91,AM60 and *** are well-established alloys,and are generally considered to be highly ***,the concept of castability in magnesium die-casting is not a well-defined characteristic or quantitative material *** a result,the author investigates the subject of castability for magnesium die-cast alloys and how it relates to the development of alloys for innovative applications or improved *** paper provides a summary of some key findings in literature on the castability of magnesium die-cast alloys,how castability is defined and evaluated,the impact of different alloying elements on the castability of magnesium alloys,and suggestions for future work.©2020 Published by Elsevier *** behalf of Chongqing University.

关键词： casting alloys property.

Segmentations of foreland belts and their tectonic mechanism in the Southwest Tarim Basin

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Science China Earth Sciences 2005年第10期48卷 1585-1598页

作者： j. Canerot j. Deramond Lab. de Bassin Dynamique Sedimentaire Universite Paul Sabatier Toulouse III 39 Allee Jules-Guesde 31062 Toulouse FranceLab. de Bassin Dynamique Sedimentaire Universite Paul Sabatier Toulouse III 39 Allee Jules-Guesde 31062 Toulouse France

Based on lots of field investigations and comprehensive interpretations of seismic profiles with outcrop cross-sections, this paper shows that the foreland belts surrounding the Southwest Tarim Foreland Basin have the regularity of segmentation along the strike of foreland belts. There are many thin-skinned thrusting systems thrusting from mountains to the basin and the arcuate back-thrusting systems to the mountains distributed at intervals in the front of West Kunlun-Pamir and Southern Tianshan. Between thrusting and back-thrusting systems, the strike-slip faults developed. The northeast uplifts and depressions of Southwest Tarim Basin correspond with the segmentation of foreland basin. The thin-skinned thrusting system is formed in the case that the thickness of sedimentary covers is less than 10 km in depth where the basement is an uplift belt in general. The back-thrusting systems and triangle zones are formed in the case that the thickness of sedimentary covers is larger than 8 km in depth where the basement is a depression zone. The main mechanics of segmentation of foreland basin are the difference of mountain uplift and deformation rate along the longitude of the mountains, the huge sedimentary rocks in different depression centers, the uplift belts and depression zones in the basement rocks, and multi-displaced weak layers in the foreland basin. The segmentation of Southwest Tarim Foreland Basin is due to the intra-plate deformation of re-orogenies of West Kunlun-Pamir and Southwest Tianshan and the co-related deformation between mountains and basement of basin since Neocene.

关键词： Southwest Tarim Basin, foreland basin,West Kunlun-Pamir and Tianshan, tectonic segmentation,structure of basement.

Faraday rotations,ellipticity,and circular dichroism in magneto-optical spectrum of moire superlattices

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Chinese Physics B 2021年第7期30卷 18-32页

作者： j A Crosse Pilkyung Moon Arts and Sciences New York University ShanghaiShanghai 200122China NYU-ECNU Institute of Physics at NYU Shanghai Shanghai 200062China Department of Physics New York UniversityNew York 10003USA

We study the magneto-optical conductivity of a number of van der Waals heterostructures,namely,twisted bilayer graphene,AB–AB and AB–BA stacked twisted double bilayer graphene and monolayer graphene and AB-stacked bilayer graphene on hexagonal boron *** the magnetic field increases,the absorption spectrum exhibits a self-similar recursive pattern reflecting the fractal nature of the energy *** twisted bilayer graphene displays only weak circular dichroism,the other four structures display strong circular dichroism with monolayer graphene and AB-stacked bilayer graphene on hexagonal boron nitride being particularly pronounced owing to strong inversion symmetry breaking properties of the hexagonal boron nitride *** the left and right circularly polarized light interact with these structures differently,plane-polarized incident light undergoes a Faraday rotation and gains an ellipticity when *** size of the respective angles is on the order of a degree.

关键词： 2D-materials van der Waals heterostructures magneto-optical conductivity graphene

Creating and moving nanoantenna cold spots anywhere

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Light(Science & Applications) 2022年第10期11卷 2335-2344页

作者： Alex j.Vernon Francisco j.Rodriguez-Fortuno Department of Physics King's College LondonStrandLondon WC2R 2LSUnited Kingdom

Cold spots are sub-wavelength regions which might emerge near a nanoantenna,should one or more components of some far-field illumination cancel out with scattered *** show that by changing only the polarisation,amplitude,and phase of two plane waves,a unique,zero-magnitude and highly sub-wavelength cold spot can be created and moved anywhere in the space around a nanoantenna of any arbitrary *** can be achieved using ultra-fast modulated pulses,or a time-harmonic *** disturbed by a change in the nanoantenna's material or position,a manufactured cold spot is fragile and could be used in nanoscale *** technique exploits the linearity of Maxwell's equations and could be adapted to manipulate any phenomena governed by the linear wave equation,including acoustic *** is a means for potentially ultra-fast sub-wavelength electric field manipulation.

关键词： illumination scattered arbitrary

Thermoelastic Analysis of Non-uniform Pressurized Functionally Graded Cylinder with Variable Thickness Using First Order Shear Deformation Theory(FSDT) and Perturbation Method

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Chinese journal of Mechanical Engineering 2015年第6期28卷 1149-1156页

作者： KHOSHGOFTAR M j MIRZAALI M j RAHIMI G H Faculty of Mechanical Engineering Tarbiat Modares University Department of Mechanical Engineering Faculty of Engineering Arak University Department of Mechanical Engineering Politecnico di Milano

Recently application of functionally graded materials（FGMs） have attracted a great deal of interest. These materials are composed of various materials with different micro-structures which can vary spatially in FGMs. Such composites with varying thickness and non-uniform pressure can be used in the aerospace engineering. Therefore, analysis of such composite is of high importance in engineering problems. Thermoelastic analysis of functionally graded cylinder with variable thickness under non-uniform pressure is considered. First order shear deformation theory and total potential energy approach is applied to obtain the governing equations of non-homogeneous cylinder. Considering the inner and outer solutions, perturbation series are applied to solve the governing equations. Outer solution for out of boundaries and more sensitive variable in inner solution at the boundaries are considered. Combining of inner and outer solution for near and far points from boundaries leads to high accurate displacement field distribution. The main aim of this paper is to show the capability of matched asymptotic solution for different non-homogeneous cylinders with different shapes and different non-uniform pressures. The results can be used to design the optimum thickness of the cylinder and also some properties such as high temperature residence by applying non-homogeneous material.

关键词： non-homogenous cylinder First order Shear Deformation Theory matched asymptotic method perturbation method functionally graded material

Strip Casting of High Performance Structural Alloys

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journal of Rare Earths 2004年第z2期22卷 78-84页

作者： S S Park j G Lee Nack j Kim Center for Advanced Aerospace Materials Pohang University of Science and TechnologyPohang 790-784Korea Center for Advanced Aerospace MaterialsPohang University of Science and TechnologyPohang 790-784Korea Center for Advanced Aerospace MaterialsPohang University of Science and TechnologyPohang 790-784Korea

There exists a great need for the development of high performance alloys due to increasing demands for energy conservation and environmental protection. Application of strip casting shows a strong potential for the improvement of properties of existing alloys and also for the development of novel alloy systems with superior properties. The present paper reviews our Center's activities in the development of high performance alloys by strip casting. Examples include (1) Al alloys, (2) wrought Mg alloys, and (3) bulk metallic glass (BMG) alloys.

关键词： strip casting 6061 Al alloy AZ Mg alloy bulk metallic glass (BMG) alloy dispersion hardening

Crystalline compounds for remediation of rare-earth fission products:A review

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journal of Rare Earths 2022年第3期40卷 365-380,I0001页

作者： Saehwa Chong Brian j.Riley Zayne j.Nelson Pacific Northwest National Laboratory RichlandWA99352USA

Rare earth(RE)-containing crystals have been investigated as media for the immobilization of RE fission products from nuclear waste *** reprocessing of spent nuclear fuel,fission products including REs,alkalis,and alkaline earths released from the *** viable option to immobilize the RE fission products is to incorporate them into chemically durable crystalline phases in specific waste *** study summarizes the crystal structures and synthesis methods of six RE-containing compounds that have applications in remediation of RE fission *** compounds include oxyapatite(AE_(2)RE_(8)(SiO_(4))_(6)O_(2)),oxychloride(REOCl),borosilicate(RE_(3)BSi_(2)O_(10)),pyrochlore(RE_(2)M_(2)O_(7)),monazite(REPO_(4)),and perovskite(REMO_(3))where AE denotes alkaline earth metals and M denotes transition *** review provides an overview of literature on the usage of these six compounds for immobilizing RE fission products and summarizes different synthesis methods for producing these *** of structural parameters with different REs in each compound are also discussed.

关键词： Rare-earth compounds Nuclear waste forms Crystal structures Synthesis of rare-earth compounds

A hybrid multi-degree-of-freedom vibration isolation platform for spacecrafts by the linear active disturbance rejection control

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Applied Mathematics and Mechanics(English Edition) 2020年第5期41卷 805-818页

作者： Weichao CHI S.j.MA j.Q.SUN College of Science Northeastern UniversityShenyang 100819China Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines Northeastern UniversityShenyang 100819China Department of Mechanical Engineering School of EngineeringUniversity of CaliforniaMercedCA 95343U.S.A.

The hybrid vibration isolation, which takes advantages of both the passive and active approaches, has been an important solution for space missions. The objective of this paper is to design a vibration isolation platform for payloads on spacecrafts with the robust, wide bandwidth, and multi-degree-of-freedom(MDOF). The proposed solution is based on a parallel mechanism with six voice-coil motors(VCMs) as the actuators. The linear active disturbance resistance control(LADRC) algorithm is used for the active control. Numerical simulation results show that the vibration isolation platform performs effectively over a wide bandwidth, and the resonance introduced by the passive isolation is eliminated. The system robustness to the uncertainties of the structure is also verified by simulation.

关键词： hybrid vibration isolation Stewart platform linear active disturbance rejection control(LADRC) stability robustness

Two-fluid modelling for cylindrical fluidized beds using kinetic theory for rough spheres

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Particuology 2020年第3期18卷 25-34页

作者： Lei Yang j.T.Padding j.A.M.Kuipers Helmholtz Institute Erlangen-Nürnberg for Renewable Energy(IEK-11) Fürther Straβe 24890429 NurnbergGermany Department of Process and Energy Delft University of Technology2628CB DelftThe Netherlands Department of Chemical Engineering and Chemistry Eindhoven University of Technology5600MB EindhovenThe Netherlands

Recently,we have extended the kinetic theory of granular flow (KTGF) to include friction between the spherical particles and tested it in rectangular *** this study,the extended KTGF implemented in cylindrical coordinates is used to model the more-commonly employed cylindrical bubbling fluidized *** attention is paid to the anti-symmetric part of the velocity gradient in the solids stress *** verification of the implementation,a comparison of the present model in the limit of zero friction with the original (frictionless) KTGF model was ***,simulations of bubbling fluidized beds of inelastic particles were performed using our extended KTGF and an effective KTGF model for inelastic particles of jenkins and *** simulation results show good agreement for the time-averaged solids volume fraction distribution and solids circulation ***,our model is validated by predicting the individual bubble behavior in dense bubbling fluidized beds containing different granular materials in a comparison with experimental data from Verma et al.(2014).The extended KTGF leads to an improved agreement with experimental bubble *** to previous work (Yang et al.,2016b,2017c),and by introducing cylindrical coordinates,the current work demonstrates that the extended KTGF improves predictions for the temporal bubble behavior of cylindrical fluidized beds.

关键词： Fluidization Frictional collision Rough particles Cylindrical bed hydrodynamics Two-fluid model