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Analysis and Validation for an Inverter-side Current Controller in LCL Grid-connected Power Systems

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Journal of Modern Power Systems and Clean Energy 2020年第2期8卷 387-398页

作者： Jose MSosa Panfilo R.martinez-Rodriguez gerardo Escobar gerardo Vazquez Andres A.Valdez-Fernandez Juan F.martinez-Garcia the Tecnologico Nacional de Mexico/ITS de Irapuato(TecNM/ITESI) IrapuatoGTO 36821Mexico the School of Sciences Autonomous University of San Luis Potosi(UASLP)San Luis PotosiSLP 78290Mexico Tecnologico de Monterrey N.L.64849Mexico

Transformerless grid-connected inverters offer greater efficiencies when transferring power from renewable energy sources to the electrical *** the grid-inverter connection is done with an LCL filter,high attenuation of switching harmonics is achieved while preserving a small-size output ***,damping must be included in the controller to assure closed-loop *** paper proposes a reference computation methodology for the inverter-side current feedback in a photovoltaic(PV)generation system connected to the grid through an LCL *** analysis of the closed-loop system stability and of the steady-state performance are presented as well as experimental validation of the closed-loop *** feedback controller includes active damping and relies on a resonant control structure which improves the ability of dealing with grid harmonic *** controller uses a reduced set of measurements,which requires the inverter-side current and grid voltage only,and assures a power factor close to unity.

关键词： LCL filter transformerless inverter grid connection inverter-side current feedback

Chromium Differentially Affects Hydrogen Peroxide Distribution in Primary and Adventitious Roots of Arabidopsis thaliana L.

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Phyton-International Journal of Experimental Botany 2020年第1期89卷 35-43页

作者： Aaron Giovanni Munguia-Rodriguez Jose Lopez-Bucio gerardo Rangel Sanchez Leon Francisco Ruiz-Herrera Yazmin Carreon-Abud Miguel martinez-Trujillo Instituto de Investigaciones Quimico-Biológicas Universidad Michoacana de San Nicolas de HidalgoEdificio B3Ciudad UniversitariaC.P58030MoreliaMichoacanMexico Facultad de Biologia Universidad Michoacana de San Nicolas de Hidalgo.Edificio RCiudad UniversitariaC.P58030 MoreliaMichoacanMexico

The post-embryonic growth of the Arabidopsis thaliana root system can be modified by different types of stress,such as sublethal concentrations of metals,which may induce the production of reactive oxygen species(ROS).In this study,the effects of different concentrations of potassium chromate(K_(2)CrO_(4))on the distribution and relative quantity of hydrogen peroxide(H_(2)O_(2))were determined in primary and adventitious roots in *** HyPer line *** line has a biosensor that specifically reports H_(2)O_(2) levels within tissues as *** root growth was inhibited at 100μM Cr(VI);in contrast,adventitious root formation was induced over the main root growth *** structures proliferated from 100-160μM Cr(VI),and much higher concentrations(180-200μM)of K_(2)CrO_(4) were required to affect their *** H_(2)O_(2) distributions were observed in the columella and lateral root cap of primary roots of plants grown in medium lacking dichromate,but following the development of toxicity symptoms,H_(2)O_(2) changed its distribution to the meristem and differentiation ***,adventitious roots had comparable H_(2)O_(2) distribution patterns in untreated plants and those exposed to Cr(VI)***,differential H_(2)O_(2) distribution correlates with the resistance of adventitious roots,but not primary roots,to dichromate and underlies cell reorganization at the apex to support growth.

关键词： Chromate hydrogen peroxide root growth meristem ion toxicity adaptation

Characterization by Thermogravimetric Analysis of Polymeric Concrete with High Density Polyethylene Mechanically Recycled

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Journal of Minerals and Materials Characterization and Engineering 2014年第4期2卷 259-263页

作者： Alma Delia Rodriguez martinez Martha Lilia Dominguez Patino Rosa Maria Melgoza Aleman gerardo Antonio Rosas Trejo Graduate Engineering and Applied Science Autonomus University of the State of MorelosChamilpaMorelosMexico Faculty of Chemical Sciences and Engineering Autonomus University of the State of MorelosChamilpaMorelosMexico Metallurgical Research Institute University Michoacana de San Nicolas de HidalgoMoreliaMichoacanMexico

This paper presents the results of the characterization by thermogravimetric analysis of a new composite material called polymeric concrete. The polymeric concrete contains micro-particles obtained from High Density Poly-Ethylene (HDPE) mechanically recycled (post-consumer bottles);the official Mexican standard NMX-E-232-SCFI-1999 considers the HDPE as the recyclable plastic material. Thermo-grams based on weight lost were obtained from the raw material (HDPE) and the polymer concrete in order to obtain the glass transition temperature (Tg) and melting temperature (Tf). The analysis conditions were defined from 20°C to 180°C and the heat rate of 1°C/minute. The results show that the glass transition temperature of polymeric concrete is 46°C and the HDPE is 38°C. These results mean that the polymeric concrete is more resistant to decomposition. With respect to the melting temperature, the results show that the 2°C difference between polymeric concrete and HDPE is not significant. The polymeric concrete with HDPE recycled can be considered as composite material thermoplastic. The new material melts when it is heated to 146°C and has the ability to be softened, processed and reprocessed with temperature and pressure changes, which make it possible to obtain molded pieces in the desired shape.

关键词： Polymer Concrete High Density Poly-Ethylene Thermogravimetric Analysis

Sequestration of a transposon-derived siRNA by a target mimic imprinted gene induces postzygotic reproductive isolation in Arabidopsis

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Sequestration of a transposon-derived siRNA by a target mimi...

Association between Aspergillus flavus Colonization and Aflatoxins Production in Immature Grains of Maize Genotypes

2018全国植物生物学大会

作者： Guifeng Wang Hua Jiang gerardo Del Toro de León German martinez Claudia K?hler Department of Plant Biology Swedish University of Agricultural SciencesLinnean Center for Plant Biology Key Laboratory of Wheat and Maize Crops Science Collaborative Innovation Center of Henan Grain CropsCollege of AgronomyHenan Agricultural University

Genomic imprinting is an epigenetic phenomenon occurring in mammals and flowering plants causing genes to be expressed depending on their *** plants,genomic imprinting is mainly confined to the endosperm,a nutritive tissue supporting embryo growth,similar to the placenta in *** we show that the paternally expressed imprinted gene PEG2 transcript is a small RNA sponge and sequesters the transposable element-derived small interfering RNA siRNA854 in the ***854 is present in the vegetative cell of pollen and transferred to the central cell of the female gametophyte after fertilization,where it is captured by *** of siRNA854 as a consequence of increased PEG2 transcript levels establishes a reproductive barrier and prevents successful hybridizations between plants differing in chromosome number(ploidy).Thus,the balance of a male gamete accumulating TEderived siRNA and a paternally-expressed imprinted gene regulate triploid seed viability,revealing a transgenerational epigenetic speciation mechanism.

关键词： transposable elements siRNAs target mimic hybridization barrier plant endosperm ploidy

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Journal of Food Science and Engineering 2013年第12期3卷 688-698页

作者： Maria Carolina de Luna-Lopez Arturo gerardo Valdivia-Flores Fernando Jaramillo-Juarez Jose Luis Reyes Raul Ortiz-martinez Teodulo Quezada-Tristfin Agricultural Sciences Centre Mycotoxicology Aguascalientes Autonomous University Aguascalientes 20131 Mexico Basic Sciences Centre Toxicology Aguascalientes Autonomous University Aguascalientes 20131 M~xico Department of Physiology and Biophysics Toxicology Center for Research and Advanced Studies-l. P. N. Mdxico D. F. 07360Mexico

Aspergillus flavus maize colonization leads to crop contamination by toxic secondary metabolites and carcinogens called aflatoxins （AF）; it has negative effects in public health and has caused economic losses in agricultural activities. Eleven genotypes of immature maize grain frequently used in Mexico were inoculated in vitro with two indigenous toxigenic strains ofA. flavus. The size of inoculum, temperature, humidity and presence of other phytopathogens were assessed. Genotypes Popcorn, C-526, Garst 8366, As910 and 30G40 showed resistance to rating of fungal colonization （FC） and AF accumulation, while 3002W, 30R39, Creole, C-922, HV313 and P3028W genotypes were less resistant. AFB~ had the highest concentrations （26.1 mg/kg ± 14.7 mg/kg）, while AFB2, AFG1 and AFG2 showed only residual concentrations 1.6, 2.0 and 4.0 ~tg/kg, respectively. Concerning FC and AF, there were significant differences （P 〈 0.01） between strains and genotype. Both strains showed significant association （P 〈 0.01） between FC and the concentrations of AFB1 and AFB2 （R2： 99.5% and 93.2%; 87.2% and 73.2%, respectively）. Results suggest that the level of resistance to fungus infection and AF accumulation is related to maize genotype. It emphasizes the relevance of developing A. flavus resistant maize genotypes as an alternative to control contamination in foodstuff intended for human and animal consumption.

关键词： AF Aspergillusflavus immature maize grain resistance Mexico.

Portal hypertensive colopathy is associated with portal hypertension severity in cirrhotic patients

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World Journal of Gastroenterology 2009年第38期15卷 4781-4787页

作者： Antonio Diaz-Sanchez Oscar Nuez-martinez Cecilia Gonzalez-Asanza Ana Matilla Beatriz Merino Diego Rincon Inmaculada Beceiro Maria Vega Catalina Magdalena Salcedo Rafael Baares gerardo Clemente Liver Unit-CIBEREHD.Hospital General Universitario Gregorio Maraón Madrid 28007Spain Gastroenterology Unit Hospital Infanta Leonor Gastroenterology Unit Hospital Infanta Sofia Department of Gastroenterology Hospital Universitario Príncipe de Asturias

AIM： To assess the prevalence of portal hypertension （PH） related colorectal lesions in liver transplant candidates, and to evaluate its association with the severity of PH. METHODS： Between October 2004 and December 2005, colonoscopy was performed in 92 cirrhotic liver transplant candidates. We described the lesions resulting from colorectal PH and their association with the grade of PH in 77 patients who underwent measurement of hepatic venous pressure gradient （HVPG）. RESULTS： Mean age was 55 years and 80.7% of patients were men. The main etiology of cirrhosis wasalcoholism （45.5%）. Portal hypertensive colopathy （PHC） was found in 23.9%, colonic varices in 7.6% and polyps in 38% of patients （adenomatous type 65.2%）. One asymptomatic patient had a well-differentiated adenocarcinoma. The manifestations of colorectal PH were not associated with the etiology of liver disease or with the Child-Pugh grade. Ninety percent of patients with colopathy presented with gastroesophageal varices （GEV）, and 27.5% of patients with GEV presented with colopathy （P = 0.12）. A relationship between higher values of HVPG and presence of colopathy was observed （19.9：1：6.2 mmHg vs 16.8 ± 5.4 mmHg, P = 0.045）, but not with the grade of colopathy （P = 0.13）. Preneoplastic polyps and neoplasm （P = 0.02） and spontaneous bacterial peritonitis （P = 0.006） were more prevalent in patients with colopathy. We did not observe any association between previous β-blocker therapy and the presence of colorectal portal hypertensive vasculopathy. CONCLUSION： PHC is common in cirrhotic liver transplant candidates and is associated with higher portal pressure.

关键词： Liver cirrhosis Portal hypertension Polyps Colopathy Liver transplantation

Refractive errors among children, adolescents and adults attending eye clinics in Mexico

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International Journal of Ophthalmology(English edition) 2017年第5期10卷 796-802页

作者： Francisco Gomez-Salazar Abraham Campos-Romero Humberto Gomez-Campana Cinthia Cruz-Zamudio Mariano Chaidez-Felix Nidia Leon-Sicairos Jorge Velazquez-Roman Hector Flores-Villasenor Secundino Muro-Amador Alma Marlene Guadron-Llanos Javier J.martinez-Garcia Joel Murillo-Llanes Jaime Sanchez-Cuen Alejando Llausas-Vargas gerardo Alapizco-Castro Ana Irineo-Cabrales Enrique Graue-Hernandez Tito Ramirez-Luquin Adrian Canizalez-Roman Salud Digna Para Todos I.A.P Culiacan Sinaloa 80000Mexico CIASaP School of Medicine Autonomous University of Sinaloa Culiacan Sinaloa 80246 Mexico Pediatric Hospital of Sinaloa Culiacan Sinaloa 80200Mexico The Women's Hospital Secretariat of Health Culiacan Sinaloa 80127 Mexico Department of Gastroenterology Regional Hospital ISSSTECuliacan 80230 Sinaloa Mexico Education and Research Department Regional general Hospital No. 1 IMSS Culiacan Sinaloa 80220 Mexico Department of Cornea and Refractive Surgery Institute of Ophthalmology 'Conde de Valenciana' Mexico City 06800Mexico

AIM：To assess the proportion of refractive errors in the Mexican population that visited primary care optometry clinics in fourteen states of Mexico. METHODS：Refractive data from 676 856 patients aged 6 to 90 y were collected from optometry clinics in fourteen states of Mexico between 2014 and 2015. The refractive errors were classified by the spherical equivalent（SE）, as follows：sphere＋？ cylinder. Myopia（SE〉-0.50 D）, hyperopia（SE〉＋0.50 D）, emmetropia（-0.50≤SE≤＋0.50）, and astigmatism alone（cylinder≥-0.25 D）. A negative cylinder was selected as a ***：The proportion（95% confidence interval） among all of the subjects was hyperopia 21.0%（20.9-21.0）, emmetropia 40.7%（40.5-40.8）, myopia 24.8%（24.7-24.9） and astigmatism alone 13.5%（13.4-13.5）. Myopia was the most common refractive error and frequency seemed to increase among the young population（10 to 29 years old）, however, hyperopia increased among the aging population（40 to 79 years old）, and astigmatism alone showed a decreasing trend with age（6 to 90y; from 19.7% to 10.8%）. There was a relationship between age and all refractive errors（approximately 60%, aged 50 and older）. The proportion of any clinically important refractive error was higher in males（61.2%） than in females（58.3%; P〈0.0001）. From fourteen states that collected information, the proportion of refractive error showed variability in different geographical areas of ***：Myopia is the most common refractive error in the population studied. This study provides the first data on refractive error in Mexico. Further programs and studies must be developed to address the refractive errors needs of the Mexican population.

关键词： refractive errors hyperopia myopia astigmatism

Microstructure evolution in low carbon boron steels

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Baosteel Technical Research 2010年第S1期4卷 48-页

作者： Eloy martinez R J gerardo CABAAS M SvMet Engineering S.A. Puebla Mexico Instituto Politecnico Nacional CNMN Mexico D.F.

Low carbon steels for long products either for automotive applications and others have been added with *** addition of boron has improved the mechanical properties such lower hardness,lower yield strength and higher *** added steels varied both in residual elements and most importantly in nitrogen content. The microstructure of B-added steels reveals very fine *** optimum cooling of B-added steels is related to the thermodynamics of boron reaction with nitrogen and other elements such as *** understanding of these reactions is key to control the final mechanical properties.

关键词： boron boron nitride thermodynamics of boron temperature

Marine turtle hatchlings use multiple sensory cues to orient their crawling towards the sea:biological and conservation policy implications

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Advances in Bioscience and Biotechnology 2011年第2期2卷 47-51页

作者： Alma Lilia Fuentes-Farias Gabriel Gutierrez-Ospina Esperanza Melendez Herrera Veronica Camarena-Ramirez gerardo Ochoa-Tovar Julieta Mendoza-Torreblanca Armida Baez-Saldana Raquel martinez-Mendez Jaime Urrutia-Fucugauchi Maria Luisa Garcia Zepeda Laboratorio de Ecofisiologia Facultad de BiologiaUniversidad Michoacana de San Nicolas de HidalgoCiudad UniversitariaMorelia MichoacanMexico58230 Laboratorio de Biologia de Sistemas Instituto de Investigaciones BiomedicasUniversidad Nacional Autonoma de MexicoCiudad UniversitariaMexico D.F.04510 Laboratorio de Paleomagnetismo Instituto de GeofisicaUniversidad Nacional Autonoma de MexicoCiudad UniversitariaMexico D.F.04510 Laboratorio de Paleontologia Facultad de BiologiaUniversidad Michoacana de San Nicolas de HidalgoCiudad UniversitariaMorelia MichoacanMexico58230 Laboratorio de Neuromorfometría Instituto Nacional de PediatríaMéxico D.F.04530

The ability of sea turtle hatchlings to find the seashore soon after hatching is thought to be exclusively dependent upon visual information. Target-oriented movements in most vertebrates, however, relay on combining information gathered through different sensory systems. Hence, in this work, we investigated whether olfactory and/or magnetic information might complement visual cues during hatchling’s seaward crawling. Acute olfactory deprivation and distorted magnetic sensation in visually competent hatchlings resulted in a scattering of seaward crawling routes among cardinal points, some of them being different from those strongly preferred by control hatchlings. In addition, blindfolded hatchlings also displayed a striking misrouting while crawling on the beach surface in spite of having intact olfactory and magnetic senses. Together these results support the notion that visual information is crucial for seaward crawling, but also that olfactory and magnetic information complement visual cues when turtle hatchlings display this behavior. Hence, the present observations suggest that multisensory cues are used by turtle hatchlings while crawling towards the sea. This work also has important implications on the design of species conservation measures and policies. In the near future, efforts must be made to identify and preserve the local natural sources of odors and magnetic cues, in addition to preventing the perturbing effects of artificial lighting on adult and hatchling turtle crawling behavior.

关键词： Olfaction Magnetoreception Vision Chelonia aggasizi Seaward orientation Reptiles Intermodal interactions Multisensory integration