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铌和钛微合金化超级马氏体不锈钢在海水中点蚀机制的研究(英文)

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热处理 2010年第1期25卷 25-29页

作者： C.A.picon F.A.P.Fernandes C.A.D.Rodrigues G.Tremiliosi-Filho L.C.Casteletti Faculdade de Engenharia de Ilha Solteira-FEIS-UNESP Escola de Engenharia de So carlos-EESC-USP Instituto de Química de So carlos-IQSC-USP

超级马氏体不锈钢(SMSS)在较高温度下具有良好的力学性能,并具有高的应力腐蚀断裂抗力和良好的可焊性,因此其在苛刻环境下的应用正日趋广泛。用于石油勘探的材料要求其具有优良的综合性能,双相不锈钢和超级双相不锈钢尽管价格昂贵,但仍... 详细信息

超级马氏体不锈钢(SMSS)在较高温度下具有良好的力学性能,并具有高的应力腐蚀断裂抗力和良好的可焊性,因此其在苛刻环境下的应用正日趋广泛。用于石油勘探的材料要求其具有优良的综合性能,双相不锈钢和超级双相不锈钢尽管价格昂贵,但仍在该领域得到了广泛应用,而具有技术和经济优势的SMSS能取代上述两种钢在石油勘探领域获得应用。通常,SMSS在许多加工行业也有望得到应用。本文研究了添加与未添加Nb或Ti的SMSS的点蚀机制和形貌。添加Nb和Ti是为了使敏化的影响减至最小,促进晶粒细化,并研究其对钢在海水中点蚀的影响,重点在于点蚀的形貌和腐蚀电位。添加与未添加Nb和Ti的钢具有相近的显微硬度和类似的回火马氏体组织。阳极极化曲线表明,用Nb微合金化的钢的腐蚀电位高于其他钢。对不同电位下点蚀的形成和扩展进行了重复试验,并采用光学显微镜进行观察。在工业用钢中,添加Ti的钢显示出了最佳的耐蚀性能——具有最高的腐蚀电位和较低的点蚀电位。添加Nb的钢尽管腐蚀电位较高,但其点蚀电位比未添加Nb的钢低。

关键词：超级马氏体不锈钢点蚀海水

Deep convolutional neural network for damaged vegetation segmentation from RGB images based on virtual NIR-channel estimation

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Artificial Intelligence in Agriculture 2022年第1期6卷 199-210页

作者： Artzai picon Arantza Bereciartua-Perez Itziar Eguskiza Javier Romero-Rodriguez carlos Javier Jimenez-Ruiz Till Eggers Christian Klukas Ramon Navarra-Mestre TECNALIA Basque Research and Technology Alliance(BRTA)Parque Tecnológico de BizkaiaC/Geldo.Edificio 700E-48160 Derio-BizkaiaSpain University of the Basque Country Plaza Torres Quevedo48013 BilbaoSpain BASF Espanola S.L.Carretera A376 41710 Utrera SevillaSpain BASF SE Speyererstrasse 267117 LimburgerhofGermany

Performing accurate and automated semantic segmentation of vegetation is a first algorithmic step towards more complex models that can extract accurate biological information on crop health,weed presence and phenological state,among ***,models based on normalized difference vegetation index(NDVI),near infrared channel(NIR)or RGB have been a good indicator of vegetation ***,these methods are not suitable for accurately segmenting vegetation showing damage,which precludes their use for downstream phenotyping *** this paper,we propose a comprehensive method for robust vegetation segmentation in RGB images that can cope with damaged *** method consists of a first regression convolutional neural network to estimate a virtual NIR channel from an RGB ***,we compute two newly proposed vegetation indices from this estimated virtual NIR:the infrared-dark channel subtraction(IDCS)and infrared-dark channel ratio(IDCR)***,both the RGB image and the estimated indices are fed into a semantic segmentation deep convolutional neural network to train a model to segment vegetation regardless of damage or *** model was tested on 84 plots containing thirteen vegetation species showing different degrees of damage and acquired over 28 *** results show that the best segmentation is obtained when the input image is augmented with the proposed virtual NIR channel(F1=0:94)and with the proposed IDCR and IDCS vegetation indices(F1=0:95)derived from the estimated NIR channel,while the use of only the image or RGB indices lead to inferior performance(RGB(F1=0:90)NIR(F1=0:82)or NDVI(F1=0:89)channel).The proposed method provides an end-to-end land cover map segmentation method directly from simple RGB images and has been successfully validated in real field conditions.

关键词： Vegetation indices estimation Vegetation coverage map Near infrared estimation Convolutional neural network Deep learning

Attosecond twisted beams from high-order harmonicgeneration driven by optical vortices

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High Power Laser Science and Engineering 2017年第1期5卷 12-19页

作者： carlos Hernandez-Garcia Laura Rego Julio San Roman Antonio picon Luis Plaja Grupo de Investigacion en Aplicaciones del Laser y Fotonica Departamento de Fisica AplicadaUniversity of SalamancaE-37008SalamancaSpain Argonne National Laboratory Argonne1L 60439USA

Optical vortices are structures of the electromagnetic field with a spiral phase ramp about a point-phase singularity,carrying orbital angular momentum(OAM). Recently, OAM has been imprinted to short-wavelength radiation through high-order harmonic generation(HHG), leading to the emission of attosecond twisted beams in the extreme-ultraviolet(XUV) regime. We explore the details of the mapping of the driving vortex to its harmonic spectrum. In particular, we show that the geometry of the harmonic vortices is convoluted, arising from the superposition of the contribution from the short and long quantum paths responsible of HHG. Finally, we show how to take advantage of transverse phase-matching to select twisted attosecond beams with different spatiotemporal properties.

关键词： attosecond science extreme-ultraviolet vortices high harmonic generation orbital angular momentum twisted beams vortexbeams

添加硬质颗粒的NiCrBSiC自熔涂层的耐磨性和耐蚀性

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热处理 2013年第1期28卷 18-21页

作者： Gladston T M Alencar Frederico A P Fernandes carlos A picon George E Totten Luiz C Casteletti Department of Materials Aeronautical and Automotive EngineeringSo Carlos School of EngineeringUniversity of So Paulo Engineering School of Ilha Solteira Department of Mechanical and Materials Engineering Portland State UniversityPortland

工程零件通常都是由于其表面产生甚至会波及整个机械结构的缺陷而失效。采用热喷涂保护涂层可以满足某些苛刻服役环境的要求,化学和石油化工行业就有这样的情况。合金基体中加入硬质颗粒能均匀地提高其硬度和耐磨性。本文研究了添加两... 详细信息

工程零件通常都是由于其表面产生甚至会波及整个机械结构的缺陷而失效。采用热喷涂保护涂层可以满足某些苛刻服役环境的要求,化学和石油化工行业就有这样的情况。合金基体中加入硬质颗粒能均匀地提高其硬度和耐磨性。本文研究了添加两种硬质颗粒的热喷涂自熔NiCrBSiC合金的微磨料磨损性能和耐蚀性能,其中,一种添加碳化硼(B4C),另一种添加以氧化钇稳定化的氧化锆(ZrO2/Y2O3)。磨损试验用氧化铝和金刚石作磨料在自由球磨损试验机上进行,腐蚀试验在天然海水中用动电位极化法进行。研究结果表明,与未加硬质颗粒的材料相比,添加硬质颗粒强化了合金的基体,提高了涂层的耐磨性和耐蚀性。添加碳化硼的NiCrBSiC合金耐磨性高于添加氧化锆的合金。添加氧化锆和碳化硼后,合金的耐蚀性均有所提高,但添加氧化锆的合金耐蚀性更好。

关键词：自熔 NiCrBSiC合金热喷涂磨损腐蚀

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含铌沉淀硬化不锈钢的耐蚀性评估(英文)

热处理 2009年第4期24卷 25-28页

作者： L.C.Casteletti F.A.P.Fernandes A.Lombardi-Neto C.A.picon G.E.Totten Escola de Engenharia de Sāo carlos-EESC-USP Faculdade de Engenharia de Ilha Solteira-FEIS-UNESP Portland State University-Oregon-USA

应航空航天工业的需求,沉淀硬化不锈钢自1945年起即开始研发。这类钢具有置换型马氏体组织,随后能产生沉淀硬化。本文研究了两种含沉淀相形成元素铌的钢的力学性能和耐蚀性,并与PH13-8Mo钢进行了比较。结果表明,一种钢的耐蚀性与PH13-8M... 详细信息

应航空航天工业的需求,沉淀硬化不锈钢自1945年起即开始研发。这类钢具有置换型马氏体组织,随后能产生沉淀硬化。本文研究了两种含沉淀相形成元素铌的钢的力学性能和耐蚀性,并与PH13-8Mo钢进行了比较。结果表明,一种钢的耐蚀性与PH13-8Mo钢类似,另一种钢的力学性能与PH13-8Mo钢相近。

关键词：不锈钢沉淀硬化腐蚀

AISI316L不锈钢等离子氮碳共渗层的表征(英文)

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热处理 2009年第3期24卷 17-20页

作者： L.C.Casteletti F.A.P.Fernandes A.Lombardi-Neto C.A.picon G.Tremiliosi-Filho G.E.Totten Escola de Engenharia de Sāo carlos-EESC-USP Escola de Engenharia de Ilha Solteira-FEIS-UNESP Instituto de Química de Sāo carlos-IQSC-USP Portland State University-Oregon

奥氏体不锈钢通过等离子氮碳共渗可显著提高其表面硬度,从而提高耐磨性而又不损害其抗腐蚀性能。本文采用光学显微镜、显微硬度和微磨损试验对经于450℃等离子氮碳共渗的AISI 316L不锈钢和所获得的渗层进行了表征。结果证明,等离子氮碳... 详细信息

奥氏体不锈钢通过等离子氮碳共渗可显著提高其表面硬度,从而提高耐磨性而又不损害其抗腐蚀性能。本文采用光学显微镜、显微硬度和微磨损试验对经于450℃等离子氮碳共渗的AISI 316L不锈钢和所获得的渗层进行了表征。结果证明,等离子氮碳共渗层由氮化铬析出相和富氮奥氏体基体组成,其硬度约850 HV;渗层总深度平均约为45μm,且很均匀;渗层的耐磨性大大高于基体。

关键词：不锈钢等离子氮碳共渗磨损