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激光冲击工艺对6061-T6铝合金侵蚀性能的影响（英文）

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Transactions of Nonferrous Metals Society of China 2016年第6期26卷 1522-1530页

作者： J.IBARRA E.RoDRíGUEZ O.JIMéNEZ G.GóMEZ-RoSAS M.FLoRES J.VERDUZCo J.CHáVEZ Universidad de Guadalajara Departamento de Ingeniería de Proyectos Universidad de Guadalajara Departamento de Física Centro Universitario de Ciencias Exactas e Ingenierías

采用激光冲击工艺处理6061-T6铝合金,研究了二氧化硅砂对其侵蚀磨损性能的影响。其中冲击角为15°、30°、60°、90°,粒子速率为37和58 m/s,采用两种激光进行辐照。采用3D轮廓测量法表征了侵蚀形貌,并采用SEM研究其侵蚀机理。结果表明... 详细信息

采用激光冲击工艺处理6061-T6铝合金,研究了二氧化硅砂对其侵蚀磨损性能的影响。其中冲击角为15°、30°、60°、90°,粒子速率为37和58 m/s,采用两种激光进行辐照。采用3D轮廓测量法表征了侵蚀形貌,并采用SEM研究其侵蚀机理。结果表明,冲击角较小时,侵蚀磨损最大。侵蚀强度和侵蚀机理不受激光冲击工艺的影响,而与侵蚀的高应变速率有关。侵蚀图之间的差异是由于激光冲击工艺造成的表面粗糙度不同。最大质量损失和最大侵蚀深度分别出现在冲击角度为15°和30°时。最后,发现了明显的侵蚀机理的转移,从低角度的切割机制到90°时的凹坑形成。

关键词： 6061-T6铝合金侵蚀磨损激光冲击工艺

Cu-WC复合材料涂层的受限烧结和磨损性能（英文）

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Transactions of Nonferrous Metals Society of China 2017年第10期27卷 2214-2224页

作者： J.L.CABEZAS-VILLA L.oLMoS H.J.VERGARA-HERNáNDEZ O.JIMéNEZ P.GARNICA D.BoUVARD M.FLoRES División de Estudios de Posgrado e Investigación Tec NM/Instituto Tecnológico de Morelia INICIT Universidad Michoacana de San Nicolás de HidalgoFco.J.Mujica S/N Universidad de Guadalajara Departamento de Ingeniería de Proyectos Univ.Grenoble Alpes CNRS SIMa P

采用固态烧结法制备Cu-WC金属基复合材料涂层。将不同体积分数(5%-30%)的WC增强颗粒与Cu颗粒混合,然后在还原性气氛和垂直膨胀计中于1000°C进行烧结。结果表明,复合材料涂层的烧结动力学受基体材料和WC颗粒的影响,WC颗粒能减缓粉末径... 详细信息

采用固态烧结法制备Cu-WC金属基复合材料涂层。将不同体积分数(5%-30%)的WC增强颗粒与Cu颗粒混合,然后在还原性气氛和垂直膨胀计中于1000°C进行烧结。结果表明,复合材料涂层的烧结动力学受基体材料和WC颗粒的影响,WC颗粒能减缓粉末径向和轴向的致密化。复合材料涂层紧实地粘附于基体上,而WC颗粒随机分布在基体中。与未添加增强剂的样品相比,添加了WC增强剂的样品的显微硬度增加,磨损量降低至原来的1/17。样品在载荷为5 N条件下的主要磨损机理为磨粒磨损,当WC增强剂的体积分数为20%时复合涂层的性能最优。

关键词：受限烧结膨胀法干滑动磨损显微硬度金属基复合材料涂层

机械球磨制备Ni_2FeSb合金的烧结动力学（英文）

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Transactions of Nonferrous Metals Society of China 2016年第8期26卷 2126-2135页

作者： F.ALVARADo-HERNáNDEZ O.JIMéNEZ G.GoNZALEZ-CASTANEDA V.BALTAZAR-HERNáNDEZ J.CABEZAS-VILLA M.ALBITER H.VERGARA-HERNáNDEZ L.oLMoS Unidad Académica de Ingeniería I Universidad Autónoma de ZacatecasJardín Juárez 147 Centro Histórico Zacatecas Zacatecas C. P. 98000 México Departamento de Ingeniería de Proyectos CUCEI Universidad de GuadalajaraBlvd. Marcelino García Barragán 1421 Olímpica Guadalajara Jalisco C. P. 44430 Mexico INICIT Universidad Michoacana de San Nicolás de HidalgoFco. J. Mujica S/N C.U. Morelia Michoacán C. P. 58060 México División de Estudios de Posgrado e Investigación TecNM/Instituto Tecnológico de MoreliaAv. Tecnológico # 1500 Colonia Lomas de Santiaguito Morelia Michoacán C. P. 58120 México

采用粉末冶金工艺制备Ni2FeSb三元形状记忆合金。利用膨胀实验研究合金的烧结动力学；采用XRD和SEM分别考察粉末样品和烧结样品的显微组织和形貌；测定烧结样品表面的显微硬度。结果表明：研磨时间对粉末样品的形状、晶粒尺寸和晶体结... 详细信息

采用粉末冶金工艺制备Ni2FeSb三元形状记忆合金。利用膨胀实验研究合金的烧结动力学；采用XRD和SEM分别考察粉末样品和烧结样品的显微组织和形貌；测定烧结样品表面的显微硬度。结果表明：研磨时间对粉末样品的形状、晶粒尺寸和晶体结构的均匀性具有显著影响。经较长时间研磨的样品具有较高的相对密度和较均匀的元素分布，且为L21和马氏体相，这些性能使合金具有形状记忆功能。在温度为750~1273K条件下，合金的激活能为109~283kJ/mol，这表明烧结过程主要由体积扩散控制。增加研磨时间和加热速率，合金的显微硬度得到提高。

关键词： Ni基形状记忆合金机械球磨固态烧结显微硬度

放电等离子烧结添加TiC开孔钛基复合材料的磨损模式（英文）

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Transactions of Nonferrous Metals Society of China 2019年第8期29卷 1653-1664页

作者： I. FARíAS L. oLMoS o. jiménez M. FLoRES A. BRAEM J. VLEUGELS Departamento de Ingeniería de Proyectos Universidad de Guadalajara 45100 Zapopan Jalisco México Instituto de Investigaciones en Ciencias de la Tierra - INICIT Universidad Michoacana de San Nicolás de Hidalgo 58060 Morelia Michoacán México KU Leuven Department of Materials Engineering Kasteelpark Arenberg 44 B-3001 Heverlee Belgium

采用放电等离子烧结法制备具有开孔隙的钛基复合材料(TMCs),研究添加TiC增强颗粒对材料摩擦性能的影响。材料中含有同等摩尔比的Ti和TiH2以及不同体积分数的TiC(0、3%、10%和30%),烧结温度为850℃。采用纳米压痕和磨损试验评估材料的纳... 详细信息

采用放电等离子烧结法制备具有开孔隙的钛基复合材料(TMCs),研究添加TiC增强颗粒对材料摩擦性能的影响。材料中含有同等摩尔比的Ti和TiH2以及不同体积分数的TiC(0、3%、10%和30%),烧结温度为850℃。采用纳米压痕和磨损试验评估材料的纳米硬度和耐磨性能,摩擦试验采用球-平面接触往复滑动模式。结果显示,随着TiC含量的增加,材料的纳米硬度从5 GPa增加到14 GPa。当TiC含量为10%时,材料的摩擦因数最低(0.2),磨损率也最低。当TiC含量较低时,样品发生粘着磨损,并伴随严重的塑性变形;当TiC含量适中时,样品表面形成机械混合层(MML);当TiC含量较高时,样品的主要磨损机制为磨粒磨损。总之,随着TiC含量的变化,材料的磨损机制、摩擦因数和磨损量也随之变化。

关键词：多孔钛放电等离子烧结磨损钛基复合材料

Multi-temporal NDVI analysis using UAV images of tree crowns in a northern Mexican pine-oak forest

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林业研究:英文版 2023年第6期34卷 1855-1867页

作者： JoséLuis Gallardo-Salazar Marcela Rosas-Chavoya Marín Pompa-García Pablito Marcelo López-Serrano Emily García-Montiel Arnulfo Meléndez-Soto Sergio Iván jiménez-jiménez Instituto de Investigaciones Agropecuarias y Forestales Universidad Michoacana de San Nicolás de Hidalgo(UMSNH)58330 MoreliaMichoacánMexico Programa Institucional de Doctorado en Ciencias Agropecuarias y Forestales Universidad Juárez del Estado de DurangoRío Papaloapan y Blvd.DurangoValle del Sur s/n34120 DurangoDurangoMéxico Facultad de Ciencias Forestales Universidad Juárez del Estado de DurangoRío Papaloapan y Blvd.DurangoValle del Sur s/n34120 DurangoDurangoMéxico Instituto de Silvicultura e Industria de la Madera Universidad Juárez del Estado de DurangoBoulevard del Guadiana 501Ciudad UniversitariaTorre de Investigación34120 DurangoMéxico INIFAP-CENID RASPA Centro Nacional de Investigación Disciplinaria en Relación Agua-Suelo-Planta-Atmósfera Margen derecha canal Sacramento km 6.5Zona industrial35140 Gómez PalacioDurangoMexico

The use of unmanned aerial vehicles(UAV)for forest monitoring has grown significantly in recent years,providing information with high spatial resolution and temporal versatility.UAV with multispectral sensors allow the use of indexes such as the normalized difference vegetation index(NDVI),which determines the vigor,physiological stress and photo synthetic activity of vegetation.This study aimed to analyze the spectral responses and variations of NDVI in tree crowns,as well as their correlation with climatic factors over the course of one year.The study area encompassed a 1.6-ha site in Durango,Mexico,where Pinus cembroides,Pinus engelmannii,and Quercus grisea coexist.Multispectral images were acquired with UAV and information on meteorological variables was obtained from NASA/PoWER database.An ANoVA explored possible differences in NDVI among the three species.Pearson correlation was performed to identify the linear relationship between NDVI and meteorological variables.Significant differences in NDVI values were found at the genus level(Pinus and Quercus),possibly related to the physiological features of the species and their phenology.Quercus grisea had the lowest NDVI values throughout the year which may be attributed to its sensitivity to relative humidity and temperatures.Although the use of UAV with a multispectral sensor for NDVI monitoring allowed genera differentiation,in more complex forest analyses hyperspectral and LiDAR sensors should be integrated,as well other vegetation indexes be considered.

关键词： Multispectral images Normalized diff erence Vegetation index Phenology Unmanned aerial vehicles Multitemporal analysis

Astrocyte evolution and human specificity

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Neural Regeneration Research 2023年第1期18卷 131-132页

作者： Carmen Falcone Verónica Martínez-Cerdeño Department of Pathology and Laboratory Medicine UC Davis School of Medicine Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children of Northern California SacramentoCAUSA

The cerebral cortex is one of the most complex structures of the mammalian central nervous system and accounts for the extraordinary cognitive abilities in primates and humans.Since the 19th century,neur ons have been believed to be the main players in the building of the brain,yet astrocytes also play a crucial role as fundamental building blocks of the cerebral cortex complexity.

关键词： cortex specificity cerebral

origin of light emission and enhanced Eu^(3+) photoluminescence in tin-containing glass

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Journal of Rare Earths 2015年第1期33卷 27-32页

作者： José A.jiménez Esteban Rosim Fachini Department of Chemistry University of North FloridaJacksonville FL 32224 USA Department of Physical Sciences General Studies Faculty University of Puerto RicoRío Piedras PR 00931 USA

A barium-phosphate glass matrix was co-doped with Sn o and Eu2o3 for investigating on material luminescent properties. optical absorption and X-ray photoelectron spectroscopy（XPS） were employed in the characterization of tin species. The prevalence of divalent tin was indicated by the XPS data in accord with a conspicuous absorption band detected around 285 nm ascribed to twofold-coordinated Sn centers（isoelectronic with Sn^2＋）. Photoluminescence（PL） excitation spectra obtained by monitoring Eu^3＋ emission from the 5D0 state revealed a broad excitation band from about 250 to 340 nm, characteristic of donor/acceptor energy transfer. Under excitation of such at 290 nm, the co-doped material exhibited a bright whitish luminescence, and a four-fold enhanced Eu3＋ emission relative to a purely Eu-doped reference. Time-resolved PL spectra recorded under the excitation at 290 nm exposed a broad band characteristic of the twofold-coordinated Sn centers and emission bands of Eu^3＋ ions, which appeared well separated in time in accord with their emission decay dynamics. The data suggested that light absorption took place at the Sn centers（donors） followed by energy transfer to Eu^3＋ ions（acceptors） which resulted in populating the 5D0 emitting state. Energy transfer pathways likely resulting in the enhanced Eu3＋ photoluminescence and the consequential light emission were discussed.

关键词： energy transfer glasses luminescence optical materials rare earths

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四平方言中元音声学研究

中国语音学报 2022年第2期 158-169页

作者：唐安琪 jiménez Jesús 湖南师范大学外国语学院西班牙瓦伦西亚大学加泰罗尼亚语系

本文从声学上分析四平方言的中元音变体。通过研究该地区女性发音人的中元音的第一、第二共振峰频率、音长和音强,讨论中元音变体数量及其特性。结果表明,四平方言区中元音存在最多的五个元音是[o],[ɣ],[ə],[■]和[e],但对于某些发音人... 详细信息

本文从声学上分析四平方言的中元音变体。通过研究该地区女性发音人的中元音的第一、第二共振峰频率、音长和音强,讨论中元音变体数量及其特性。结果表明,四平方言区中元音存在最多的五个元音是[o],[ɣ],[ə],[■]和[e],但对于某些发音人来说,[■]和[e]被视为同一个元音的变体。在学界,尽管有些学者根据互补分布规则认为中元音只需一个音位,但由于这五个变体之间较远的声学距离,大部分学者根据唇形的圆展和发音部位的不同,普遍认为中元音需多个独立的音位。

关键词：中元音四平方言共振峰音长音强

New approaches in the treatment of hepatitis C

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World Journal of Gastroenterology 2016年第4期22卷 1421-1432页

作者： rocío gonzález-grande miguel jiménez-pérez carolina gonzález arjona josémostazo torres Liver Transplantation and Hepatology Unit UGC de Aparato DigestivoHospital Regional Universitario29010 MalagaSpain

About 130-170 million people, is estimated to be infected with the hepatitis C virus(HCV). Chronic HCV infection is one of the leading causes of liverrelated death and in many countries it is the primaryreason for having a liver transplant. The main aim of antiviral treatment is to eradicate the virus. Until a few years ago the only treatment strategy was based on the combination of pegylated interferon and ribavirin(PEG/RBV). However, in genotypes 1 and 4 the rates of viral response did not surpass 50%, reaching up to 80% in the rest. In 2011 approval was given for the first direct acting antiviral agents(DAA), boceprevir and telaprevir, for treatment of genotype 1, in combination with traditional dual therapy. This strategy managed to increase the rates of sustained viral response(SVR) in both naive patients and in retreated patients, but with greater toxicity, interactions and cost, as well as being less safe in patients with advanced disease, in whom this treatment can trigger decompensation or even death. The recent, accelerated incorporation since 2013 of new more effective DAA, with pan-genomic properties and excellent tolerance, besides increasing the rates of SVR(even up to 100%), has also created a new scenario: shorter therapies, less toxicity and regimens free of PEG/RBV. This has enabled their almost generalised applicability in all patients. However, it should be noted that most of the scientific evidence available is based on expert opinion, case-control series, cohort studies and phase 2 and 3 trials, some with a reduced number of patients and select groups. Few data are currently available about the use of these drugs in daily clinical practice, particularly in relation to the appearance of side effects and interactions with other drugs, or their use in special populations or persons with the less common genotypes. This situation suggests the need for the generalised implementation of registries of patients receiving antiviral therapy. The main inconvenience of these new drugs is their high cost.

关键词： Hepatitis C Treatment Direct acting antiviralagents Patients outcome