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A legendre orthogonal moment based 3D edge operator

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Science China(Physics,Mechanics & Astronomy) 2005年第1期48卷 1-13页

作者： j.l.Dillenseger lTSI University of Rennes IFrance

This paper presents a new 3D edge operator based on legendre orthogonal moments. This operator can be used to extract the edge of 3D object in any window size,with more accurate surface orientation and more precise surface location. It also has full geometry meaning. Process of calculation is considered in the moment based *** can greatly speed up the computation by calculating out the masks in advance. We integrate this operator into our rendering of medical image data based on ray casting algorithm. Experimental results show that it is an effective 3D edge operator that is more accurate in position and orientation.

关键词： legendre moment, 3D edge operator, surface location, surface orientation, ray casting.

Development and Electrochemical Studies of Ruthenium Based Mixed Oxide Catalyst Electrodes for Chlorine Evolution

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Chemical Research in Chinese Universities 2002年第2期18卷 133-138页

作者： l.X.Yang j.P.G.Farr Department of Chemical and Processing Engineering University of Newcastle Merz CourtNewcastle upon Tyne NE17RU School of Metallurgy and Materials The University of Birmingham EdgbastonBirmingham B152TTUK

Experimental results are presented which allow comparison of the electrochemical performance of RuO 2/Ti, Ru 0 3 Sn 0 7 O 2/Ti and Ru 0 3 V 0 7 O 2/Ti catalysts prepared on a titanium substrate by thermal decomposition from respective precursors. The highest activity for chlorine evolution is observed on the Ru 0 3 V 0 7 O 2/Ti electrode, lower on Ru 0 3 Sn 0 7 O 2/Ti and least on RuO 2/Ti. Voltammograms obtained in the polarisable region are used to characterize the different electrodes. Further more an analysis of the catalytic activity and reaction kinetics of the developed electrodes in NaCl are presented.

关键词： Catalyst Cl_(2) evolution Ruthenium oxide

Hilbert Space of Probability Density Functions Based on Aitchison Geometry

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Acta Mathematica Sinica,English Series 2006年第4期22卷 1175-1182页

作者： j.j.EGOZCUE j.l.DIAZ-BARRERO V.PAWlOWSKY-GlAHN Applied Mathematics Ⅲ Universitat Politàcnica de CatalunyaJordi Girona 1-3C208034BarcelonaSpain Applied Mathematics Ⅲ Universitat Politàcnica de CatalunyaJordi Girona 13C208034BarcelonaSpain Informatics and Applied Mathematics Universitat de GironaCampus MontiliviP417071GironaSpain

The set of probability functions is a convex subset of l1 and it does not have a linear space structure when using ordinary sum and multiplication by real constants. Moreover, difficulties arise when dealing with distances between densities. The crucial point is that usual distances are not invariant under relevant transformations of densities. To overcome these limitations, Aitchison＇s ideas on compositional data analysis are used, generalizing perturbation and power transformation, as well as the Aitchison inner product, to operations on probability density functions with support on a finite interval. With these operations at hand, it is shown that the set of bounded probability density functions on finite intervals is a pre-Hilbert space. A Hilbert space of densities, whose logarithm is square-integrable, is obtained as the natural completion of the pre-Hilbert space.

关键词： Bayes' theorem Fourier coefficients Haar basis Aitchison distance Simplex least squares approximation

Advances in additively manufactured titanium alloys by powder bed fusion and directed energy deposition:Microstructure,defects,and mechanical behavior

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journal of Materials Science & Technology 2024年第16期183卷 32-62页

作者： H.Y.Ma j.C.Wang P.Qin Y.j.liu l.Y.Chen l.Q.Wang l.C.Zhang Centre for Advanced Materials and Manufacturing School of EngineeringEdith Cowan University270 Joondalup DriveJoondalupPerthWA 6027SA School of Engineering M050The University of Western Australia35 Stirling HighwayCrawleyPerthWA 6009SA Institute of Metals College of Material Science and EngineeringChangsha University of Science&TechnologyChangsha 410004China School of Material Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China State Key laboratory of Metal Matrix Composites School of Material Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Ti and its alloys have been broadly adopted across various industries owing to their outstanding proper-ties,such as high strength-to-weight ratio,excellent fatigue performance,exceptional corrosion resistance and so *** manufacturing(AM)is a complement to,rather than a replacement for,traditional manufacturing *** enhances flexibility in fabricating complex components and resolves machin-ing challenges,resulting in reduced lead times for custom ***,owing to distinctions among various AM technologies,Ti alloys fabricated by different AM methods usually present differences in mi-crostructure and defects,which can significantly influence the mechanical performance of built ***,having an in-depth knowledge of the scientific aspects of fabrication and material properties is crucial to achieving high-performance Ti alloys through different AM *** article reviews the mechanical properties of Ti alloys fabricated by two mainstream powder-type AM techniques:powder bed fusion(PBF)and directed energy deposition(DED).The review examines several key aspects,en-compassing phase formation,grain size and morphology,and defects,and provides an in-depth analysis of their influence on the mechanical behaviors of Ti *** review can aid researchers and engi-neers in selecting appropriate PBF or DED methods and optimizing their process parameters to fabricate high-performance Ti alloys for a wide range of industrial applications.

关键词： Powder bed fusion Directed energy deposition Titanium alloys Phase transformation Defects Mechanical property

Effect of long-term Thermal Exposure on Microstructure and Stress Rupture Properties of GH3535 Superalloy

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journal of Materials Science & Technology 2015年第3期31卷 269-279页

作者： T.liu j.S.Dong l.Wang Z.j.li X.T.Zhou l.H.lou j.Zhang School of Materials Science and Engineering Dalian University of Technology Institute of Metal Research Chinese Academy of Sciences Shanghai Institute of Applied Physics Chinese Academy of Sciences Shenyang National laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences

The evolution of microstructure and the stress rupture properties of long term thermally exposed GH3535 alloy have been investigated. It was found that M6 C carbides presented in the solid solution heat treated samples. During long term thermal exposure at 700 C, fine M12 C carbides precipitated preferentially at grain boundaries. These carbides coexisted with the pre-exiting M6 C. The stress rupture life of700 C/1000 h exposed sample under creep testing at 650 C/324 MPa is 93 h. It is much longer than that of the solid solution samples. No noticeable changes could be detected in both the microstructure and stress rupture lives when the samples were exposed for time longer than 1000 h M12 C carbides were found to be beneficial to the creep properties. The cracks initiated at the interface of M6 C carbides and matrix, which led to a lower creep rupture life.

关键词： GH3535 superalloy long term thermal exposure Micro

Structural evolution of Al–8%Si hypoeutectic alloy by ultrasonic processing

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journal of Materials Science & Technology 2017年第11期33卷 1235-1239页

作者： j.Y.Wang B.j.Wang l.F.Huang Department of Applied Physics Northwestern Polytechnical University Xi'an 710072 China

High intensity power ultrasound was respectively introduced into three different solidification stages of Al–8%Si hypoeutectic alloy, including the fully liquid state before nucleation, the nucleation and growth process of primary α（Al） phase and l →（Al）＋（Si） eutectic transformation period. It is found that both the primary α（Al） phase and（Al ＋ Si） eutectic structure were refined by different degrees with various growth morphologies depending on the ultrasonic treatment stage. Based on the experimental results,the cavitation-induced nucleation due to the high undercooling caused by the collapse of tiny cavities was proposed as the major reason for refining the primary α（Al） phase. Meanwhile, obvious eutectic morphological change was observed only when ultrasound was directly introduced in the eutectic transformation stage, in which typical divorced eutectics and（Al ＋ Si） eutectic cells with symmetrical flower shape were formed at the top of the alloy sample. The introduction of ultrasound in each solidification stage also improves the yield strength of Al–8% Si alloy to a diverse extent.

关键词： Solidification Microstructure Metals and alloys Power ultrasound Refinement

[Recent progress in mass spectrometry imaging using nanospray desorption electrospray ionization]

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Se pu = Chinese journal of chromatography 2025年第1期43卷 43-49页

作者： jing-Bo Wang Xiao-lan li Rui-Xia Fan Ping lü Rui-Chuan Yin West China School of Pharmacy Sichuan University Chengdu 610041 China.

Ambient mass spectrometry imaging (MSI) enables hundreds of analytes in tissue sections to be directly mapped at atmospheric pressure with minimal sample preparation. This field is currently experiencing rapid growth, with numerous reported ambient ionization techniques resulting in a "hundred flowers bloom" situation. Nanospray desorption electrospray ionization (nano-DESI), developed by the laskin group in 2010, is a widely used liquid-extraction-based ambient ionization technique that was first used for mass spectrometry imaging of tissue in 2012. The nano-DESI probe comprises a primary capillary and a nanospray capillary, with the latter efficiently transferring analyte-containing droplets via a tiny liquid bridge formed between the probe and sample surface, thereby enabling nanoelectrospray ionization (nano-ESI) in front of the inlet of a mass spectrometer. The advantages of nano-DESI MSI include minimal sample preparation, high spatial resolution, and high sensitivity. These features are well-suited for imaging various sample types, including frozen tissue sections, microbial communities, and environmental samples. A PubMed-database search using the "nano-DESI" keyword revealed 72 related articles in the 2010-2024 period, with 34 of them published between 2021 and 2024, which indicates that nano-DESI has rapidly developed as an ambient ionization technique over recent years. Herein, we briefly introduce key nano-DESI-MSI research progress reported in the past three years with the aim of better understanding and facilitating the use of this technology. We first discuss advances in ion-source development. Since no commercial nano-DESI source exists, designing and constructing ion sources remain technical challenges that limit its development. Nano-DESI has been successfully coupled with various types of mass spectrometer, including lTQ Orbitrap, quadrupole-Orbitrap (Q Exactive), 6560 IM QTOF, timsTOF Pro2, triple quadrupole, and FTICR. These couplings have signi

关键词： ambient mass spectrometry imaging nanospray desorption electrospray ionization spatial proteomics structural characterization of lipid

Cleaning Radio Frequency Interference in Pulsar-Folded Data Based on the Conditional Random Fields with an Adaptive Prior

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Research in Astronomy and Astrophysics 2023年第10期23卷 184-191页

作者： Xue Chen j.l.Han W.Q.Su Z.l.Yang D.j.Zhou National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China CAS Key laboratory of FAST NAOCChinese Academy of SciencesBeijing 100101China

Radio astronomy observations are frequently impacted by radio frequency interference(RFI).We propose a novel method,named 2σCRF,for cleaning RFI in the folded data of pulsar observations,utilizing a Bayesian-based model called conditional random fields(CRFs).This algorithm minimizes the“energy”of every pixel given an initial *** standard deviations(i.e.,rms values)of the folded pulsar data are utilized as pixels for all subintegrations and ***-RFI data without obvious interference is treated as“background noise,”while RFI-affected data have different classes due to their exceptional rms *** initial labeling can be automated and is adaptive to the actual *** CRF algorithm optimizes the label category for each pixel of the image with the prior initial *** demonstrate the efficacy of the proposed method on pulsar folded data obtained from Five-hundred-meter Aperture Spherical radio Telescope *** can effectively recognize and tag various categories of RFIs,including broadband or narrowband,constant or instantaneous,and even weak RFIs that are unrecognizable in some pixels but picked out based on their *** results are comparable to those obtained via manual labeling but without the need for human intervention,saving time and effort.

关键词： methods:data analysis techniques:image processing (stars:)pulsars:general

Effect of Silver Content on Microstructure and Properties of Brass/steel Induction Brazing joint Using Ag-Cu-Zn-Sn Filler Metal

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journal of Materials Science & Technology 2011年第4期27卷 377-381页

作者： j. Cao l.X. Zhang H.Q. Wang l.Z. Wu j.C. Feng State Keylab of AdvanCed Welding Production Technology Harbin Instituteof Technology Harbin 150001 China Center for Composite Materials and Structures Harbin Institute of Technology Harbin 150001 China

The induction brazing of brass to steel using Ag-Cu-Zn-Sn filler metal was investigated in this study. The influence of A8 content on the microstructure and properties were analyzed by means of optical microscopy, scanning electron microscopy and electron probe microanalysis. Defect free joint was achieved using Ag- Cu-Zn-Sn filler metal. The microstructure of the joint was mainly composed of Ag-based solid solution and Cu-based solid solution. The increase of A8 content and the cooling rate both led to the increase of the needle like eutectic structure. The tensile strength decreased with the increase of Ag content. The tensile strength at room temperature using Ag25CuZnSn filler metal reached 445 MPa. All fractures using Ag-Cu-Zn-Sn filler metal presented ductile characteristic.

关键词： Induction brazing Brass Steel Microstructure Tensile strength