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Influence of velocity profile on calibration function of Lorentz force flowmeter

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Applied Mathematics and Mechanics(English Edition) 2014年第8期35卷 993-1004页

作者： c.StELIAN 于洋李本文 A.tHESS Institute of thermodynamics and Fluid Mechanics Ilmenau University of TechnologyIlmenau 98684Germany Department of Physics West University of TimisoaraTimisoara 300233Romania Key Laboratory of Electromagnetic Processing of Materials Northeastern University Institute of Engineering thermodynamics German Aerospace CenterStuttgart 70569Germany

A Lorentz force flowmeter is a noncontact electromagnetic flow-measuring device based on exposing a flowing electrically conducting liquid to a magnetic field and measuring the force acting on the magnet system. the measured Lorentz force is proportional to the flow rate via a calibration coefficient which depends on the velocity distribution and magnetic field in liquid. In this paper, the influence of different velocity profiles on the calibration coefficient is investigated by using numerical simulations. the Lorentz forces are computed for laminar flows in closed and open rectangular channels, and the results are compared with the simplified case of a solid conductor moving at a constant velocity. the numerical computations demonstrate that calibration coefficients for solid bodies are always higher than for liquid metals. Moreover, it can be found that for some parameters the solid-body calibration coefficient is almost twice as high as for a liquid metal. these differences are explained by analyzing the patterns of the induced eddy currents and the spatial distributions of the Lorentz force density. the result provides a first step for evaluating the influence of the laminar velocity profiles on the calibration function of a Lorentz force flowmeter.

关键词： laminar flow numerical simulation electromagnetic velocimetry

P2X7 receptor signaling during adult hippocampal neurogenesis

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Neural Regeneration Research 2019年第10期14卷 1684-1694页

作者： Hannah c. Leeson tailoi chan-Ling Michael D. Lovelace Jeremy c. Brownlie ben J. Gu Michael W. Weible II Australian Institute for Bioengineering and Nanotechnology The University of QueenslandBrisbaneQueenslandAustralia Griffith Institute for Drug Discovery Griffith UniversityBrisbaneQueenslandAustralia Discipline of Anatomy and Histology School of Medical ScienceThe University of SydneySydneyNew South WalesAustralia Bosch Institute The University of SydneySydneyNew South WalesAustralia Applied Neurosciences Program Peter Duncan Neurosciences Research UnitSt. Vincent’s Centre for Applied Medical ResearchSydneyNew South WalesAustralia Faculty of Medicine St. Vincent’s Clinical SchoolUniversity of New South Wales SydneySydneyNew South WalesAustralia School of Environment and Science Griffith UniversityBrisbaneQueenslandAustralia Florey Institute of Neuroscience and Mental Health University of MelbourneMelbourneVictoriaAustralia

Neurogenesis is a persistent and essential feature of the adult mammalian *** neurons generated from resident pools of stem or progenitor cells provide a mechanism for the formation and consolidation of new *** of hippocampal neurogenesis is complex and multifaceted,and numerous signaling pathways converge to modulate cell proliferation,apoptosis,and clearance of cellular debris,as well as synaptic integration of newborn immature *** expression of functional P2X7 receptors in the central nervous system has attracted much interest and the regulatory role of this purinergic receptor during adult neurogenesis has only recently begun to be explored.P2X7 receptors are exceptionally versatile:in their canonical role they act as adenosine triphosphate-gated calcium channels and facilitate calcium-signaling cascades exerting control over the cell via calcium-encoded sensory proteins and transcription factor activation.P2X7 also mediates transmembrane pore formation to regulate cytokine release and facilitate extracellular communication,and when persistently stimulated by high extracellular adenosine triphosphate levels large P2X7 pores form,which induce apoptotic cell death through cytosolic ion ***,as a scavenger receptor P2X7 directly facilitates phagocytosis of the cellular debris that arises during neurogenesis,as well as during some disease *** how P2X7 receptors regulate the physiology of stem and progenitor cells in the adult hippocampus is an important step towards developing useful therapeutic models for regenerative *** review considers the relevant aspects of adult hippocampal neurogenesis and explores how P2X7 receptor activity may influence the molecular physiology of the hippocampus,and neural stem and progenitor cells.

关键词： P2X7 P2X7R adult neurogenesis neural stem cells neural progenitor cells hippocampus SGZ calcium signaling purinergic signaling

Effect of thermal Refining on Mechanical Properties of Annealed SAE 4130 by Multilayer GtAW

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Journal of Iron and Steel Research International 2012年第7期19卷 71-78页

作者： I K Lee c L chung Y t Lee Y t chien Department of Materials Science and Engineering Da-Yeh University

During the first welding process in manufacturing a precise seam container, the steel material must first undergo a full annealing treatment. Multilayer welding operations are conducted and then applied with refining treatment to obtain the goal by hardening. the influence of thermal refining on mechanical properties of annealed SAE 4130 by multilayer GtAW （gas tungsten arc welding） was discussed. the AW （annealing＋welding） and AWSt （annealing＋welding＋solution＋tempering） occurred with a minimum hardness value at GGHAZ （grain growth heat affected zone） due to coarse grain growth~ the hardness occurred with sudden drops between the multilayer welding, but was still larger than the minimum value at HAZ （heat affected zone）. the welded joint efficiency of the AWSt was 89.9%, with the elongation reduced to 77.2% of ASt （annealing＋solution＋tempering）. the cross section of the tensile samples both appeared with a uniform dimple-shaped structure, and however the necking for ASt was greater than that for AWSt. the impact value for AWSt was 166.5% of ASt. Moreover, from microstructure observations, it was found that AWSt had a greater tendency to ductile failure than ASt. these results can be inferred., the process of steady pressure and the initial position of the precision tube breakage HAZ. However, when stress occurs instantly, HAZ can absorb more energy, therefore the initial damage does not occur.

关键词： thermal refining SAE 4130 multilayer welding GtAW

three-dimensional modelling of shear keys in concrete gravity dams using an advanced grillage method

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Water Science and Engineering 2020年第3期13卷 223-232页

作者： Mahdi ben Ftima Steephane Lafrance Pierre Leeger Polytechnique Montreal Montreal University CampusMontrealH3C 3A7Canada

contraction joint shear keys are resilient features of gravity dams that can be considered to increase the sliding safety factors or minimise seismic residual sliding displacements,allowing costly remedial actions to be *** paper presents a novel,robust,and computationally efficient three-dimensional(3D)modelling and simulation strategy of gravity dams,using a series of adjacent cantilever beam elements to represent individual *** monoliths are interconnected in the longitudinal direction by 3D no-tension link elements representing the lumped shear key stiffness contributions at a particular *** objective is to assess the shear key internal force demands,including the axial force,shear,and moment *** key demand-capacity ratios can then be assessed with related multi-axial failure *** 3D link element stiffness coefficients were derived from a series of 3D finite element(FE)solid models with a detailed representation of geometrical features of multiple shear *** results from the proposed method based on advanced grillage analysis show strong agreement with reference solutions from 3D FE solid models,demonstrating high accuracy and performance of the proposed *** application of the proposed advanced grillage method to a dam model with two monoliths clearly shows the advantage of the proposed method,in comparison to the classical approach used in practise.

关键词： Gravity dam Shear keys Seismic analysis Grillage analysis Finite element model Multi-scale approach

Bulk nanocrystalline W-ti alloys with exceptional mechanical properties and thermal stability

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Journal of Materials Science & technology 2022年第19期114卷 16-28页

作者： H.X.Xue X.c.cai B.R.Sun X.Shen c.c.Du X.J.Wang t.t.Yang S.W.Xin t.D.Shen clean Nano Energy center State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao 066004China cSSc 723rd Research Institute China State Shipbuilding Corporation LimitedYangzhou 225000China

Nanocrystalline(Nc)W metals and alloys often exhibit higher radiation tolerance and strength than their coarse-grained ***,their thermal stability is low,making it difficult to achieve bulk Nc W metals and alloys by consolidation using conventional techniques such as pressure-less sintering,hot-explosive-compaction sintering,and spark plasma *** we report the synthesis and mechanical properties of bulk Nc W_(100-x)ti_(x)(x=10 at.%-30 at.%)alloys prepared by consolidating mechanically alloyed Nc powders under a high-temperature/high-pressure *** 20 at.%-30 at.%ti largely improves the sinterability of Nc W-ti alloy *** room-temperature microhardness and compressive yield strength of consolidated bulk Nc W_(80)ti_(20) alloy are∼16.9 and 6.0 GPa,respectively,which are mainly caused by grain boundary strengthening and significantly higher than those of previously reported W and W *** ultimate compressive strength of bulk Nc W_(80)ti_(20) measured between 900 and 1100°c deceases with increasing *** behavior can be explained by the activation of Rachinger grain boundary *** grain growth is observed in bulk Nc W_(80)ti_(20) after compression at 1000°*** calculation suggests that it is the segregation of ti at grain boundaries that decreases the specific grain boundary free energy and makes the Nc W_(80)ti_(20) alloy thermodynamically stable.

关键词： Nanocrystalline W-ti alloys Segregation Grain boundary energy Strength Hardness

Unified FPGA Design for the HEVc Dequantization and Inverse transform Modules

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computers, Materials & continua 2022年第6期71卷 4319-4335页

作者： turki M.Alanazi Ahmed ben Atitallah Department of Electrical Engineering Jouf UniversitySakakaAljouf2014Saudi Arabia

As the newest standard,the High Efficiency Video coding(HEVc)is specially designed to minimize the bitrate for video data transfer and to support High Definition(HD)and ULtRA HD video resolutions at the cost of increasing computational complexity relative to earlier standards like the ***,real-time video decoding with HEVc decoder becomes a challenging ***,the Dequantization and Inverse transform(DE/It)are one of the computationally intensive modules in the HEVc decoder which are used to reconstruct the residual ***,in this paper,a unified hardware architecture is proposed to implement the HEVc DE/It module for all transform Unit(tU)block size,including 4×4,8×8,16×16 and 32×*** architecture is designed using the High-Level Synthesis(HLS)and the Low-Level Synthesis(LLS)methods in order to compare and determine the best method to implement in real-time the DE/It *** fact,the c/c++programming language is used to generate an optimized hardware design for DE/It module through the Xilinx Vivado HLS *** the other hand,the LLS hardware architecture is designed by the VHSIc Hardware Description language(VHDL)and using the pipeline technique to decrease the processing *** experimental results on the Xilinx Xc7Z020 FPGA show that the LLS design increases the throughput in term of frame rate by 80%relative to HLS design with a 4.4%increase in the number of Look-Up tables(LUts).compared with existing related works in literature,the proposed architectures demonstrate significant advantages in hardware cost and performance improvement.

关键词： HEVc decoder dequantization IDct/IDSt LLS design HLS design FPGA

Numerical simulation of a sheet metal extrusion process by using thermal-mechanical coupling EAS FEM

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Journal of University of Science and technology Beijing 2002年第5期9卷 378-382页

作者： Zhanghuachen t.c.Lee 等 AppliedScienceSchool UniversityofScienceandTechnologyBeijingBeijing100083China DepartmentofIndustrialsystemEngineering TheHongKongPolytechnicunivetsityChina

the thermal-mechanical coupling finite element method(FEM)was usedto simulate a non-isothermal sheet metal extrusion process. On thebasis of the finite plasticity consistent with multiplicativedecomposition of the deformation gradient, the enhanced as- sumedstrain(EAS)FEM was applied to carry out the numerical simulation. Inorder to make the computation reliable ad avoid hour- glass mode inthe EAS element under large compressive strains, an alterative formof the original enhanced deformation gradient was employed. Inaddition, reduced factors were used in the computation of the elementlocal internal parameters and the enhanced part of elementalstiffness.

关键词： enhanced assumed strain element thermal-mechanical coupling process houyrglass mode

Effect of temperature and pH value on cation exchange performance of a natural clay for selective(cu2+,co2+) removal:Equilibrium,sorption and kinetics

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Progress in Natural Science:Materials International 2013年第1期23卷 23-35页

作者： Ramzi chalghaf Walid Oueslati Marwa Ammar Hafsia ben Rhaiem Abdesslem ben Haj Amara UR05/13-01:Physique des Matériaux Lamellaires et Nanomatériaux Hybrides(PMLNMH) Facultédes Sciences de BizerteZarzouna 7021Tunisia

this work aims at investigating the strain effect,created by varying pH solution and continuous heating cycle,on the cation exchange process in the case of Na-rich montmorillonite sample in contact with bi-ionic solution with variable concentration,saturated respectively by co2+ and cu2+ *** ionic exchange process is characterized using XRD analysis obtained through the comparison of experimental XRD patterns with calculated ones,which allowed us to determine several structural parameters related to the nature,abundance,size,position and organization of exchangeable cation and water molecule in the interlamellar space along the ***,the proposed theoretical models,for the stressed samples,show that the structure presents an interstratified hydration character and proves the coexistence of more than two ''crystallite'' specie in the *** perturbation types have an obvious effect on the selective exchange process for all stressed samples,where the interlayer space is characterized by the coexistence of more one exchangeable cation.

关键词： Geological membrane Soil decontamination Alkaline strain thermal stress Quantitative XRD analysis Ionic exchange process

Fullwave Doppler reflectometry simulations for density turbulence spectra in ASDEX Upgrade using GENE and IPF-FD3D

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Plasma Science and technology 2020年第6期22卷 41-48页

作者： c LEcHtE G D cONWAY tGÖRLER t HAPPEL the ASDEX Upgrade team Institute of Interfacial Process Engineering and Plasma technology IGVP Universität StuttgartD-70569 StuttgartGermany Max-Planck-Institute for Plasma Physics D-85748 GarchingGermany 不详

Doppler reflectometry is an important microwave diagnostic for turbulent fusion plasmas.A microwave beam is scattered off density fluctuations,with wavenumbers according to incident frequency and relative *** way,a density fluctuation spectrum is ***,the correspondence between fluctuation power and scattered microwave power is strongly *** these processes numerically therefore requires fullwave simulations(IPF-FD3 D),with density fluctuations supplied by a separate plasma turbulence code(GENE).Earlier such attempts suffered from the low number of data points in the‘interesting’part of the spectrum,where a power law had to be fitted to 4 or 5 *** has been overcome with recent simulations,which now show a much better agreement with experimental data.

关键词： plasma diagnostics Doppler reflectometry simulation microwaves