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journal of Wuhan University of Technology(Materials Science) 2015年第5期30卷 873-881页

作者： Galaviz-pérez j A CHEN Fei SHEN Qiang vargas-garcía j r 张联盟 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Dept.of Materials and Metallurgical Eng. National Polytechnic Institute

Sb-doped Sn O2(ATO) thin films have been prepared using the spin coating method by selecting the proper amount of acetylacetone as solution modifier. All ATO powders and films exhibited the cassiterite rutile-like structure in a crystal size below 10 nm under all the experimental conditions and a nonpreviously reported crystal structure was observed at high acetylacetone loads. The acetylacetone molar ratio influenced notably the optical and electrical properties of ATO films. When prepared at an acetylacetone molar ratio of 4, ATO films exhibited optical transparencies above 90% in the visible region and above 40% in the UV region for thicknesses of 100 and 300 nm. Films in a thickness of 100 nm and at an annealing temperature of 650 ℃ accounted for a high transparency of 97% in the visible wavelength. Films prepared at an acetylacetone molar ratio of 4 exhibited an electric resistivity of 1.33×10-3 Ω·cm at an annealing temperature of 650 ℃. The optimal Sb content for ATO films was found to be 8 at%. The relationships among the properties of starting solutions, the experimental parameters, and properties of ATO films are discussed.

关键词： tin oxide films antimony doping acetylacetone optical transparency electric properties

Preparation,Characterization and Electronic Properties of Fluorine-doped Tin Oxide Films

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journal of Wuhan University of Technology(Materials Science) 2016年第1期31卷 48-51页

作者： Velázquez-Nevárez G A vargas-garcía j r Lartundo-rojas L CHEN Fei SHEN Qiang ZHANG Lianmeng Deptartment of Materials and Metallurgical Engineering National Polytechnic Institute Nanosciences and Micro and Nanotechnology Center National Polytechnic Institute State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology

Tin oxide（SnO2） and fluorine doped tin oxide（FTO） films were prepared on glass substrates by sol-gel spin-coating using SnCl4 and NH4F *** doping concentration was fixed at 4 at%and 20 at%by controlling precursor sol *** exhibited the tetragonal rutile-type crystal structure regardless of fluorine *** and highly transparent FTO films,with more than 85%of optical transmittance,were obtained by annealing at 600℃.Florine doping of films was verified by analyzing the valence band region obtained by *** was found that the fluorine doping affects the shape of valence band of SnO2 *** addition,it was observed that the band gap of SnO2 is reduced as well as the Fermi level is upward shifted by the effect of fluorine doping.

关键词： tin oxide films fluorine doping energy band diagram

Population dynamics of three lizard species from the genus Sceloporus:short-term changes in demographic parameters

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Integrative Zoology 2019年第6期14卷 542-560页

作者： Selene vargas-garcÍA Víctor ArGAEZ Israel SOLANO-ZAVALETA j.jaime ZÚÑIGA-VEGA Graduate Program in Biological Sciences National Autonomous University of MexicoUniversity CityMexico CityMéxico Department of Ecology and Natural resources Faculty of SciencesNational Autonomous University of MexicoUniversity CityMexico CityMéxico.

Most demographic studies focus on numerical changes that occur within populations across ***,typically studies at an interannual scale do not provide information on the particular times of the year(particular months or seasons)when rates of survival,recruitment,or migration increase or decrease due to physiological,behavioral or ecological *** monthly or seasonal changes in demographic parameters may lead to substantial variations in population *** this study,we collected capture-mark-recapture data on 3 species of lizards of the genus Sceloporus(Sceloporus torquatus,Sceloporus grammicus and Sceloporus megalepidurus)found in ecologically similar habitats to examine potential changes in demographic rates among 3 different climatic seasons:rainy,cold-dry and warm-dry *** tested different hypotheses about the effect of these seasons on survival,recruitment of new adults,and temporary *** found that during the season with severe thermal constraints,the cold-dry season,survival of *** decreased *** also detected a considerable increase in the recruitment rate of *** during the rainy season,when these lizards are establishing territories and finding *** contrast,we found no evidence of intra-annual changes in the rate of temporary *** addition,we calculated abundance and population growth rates for each species and for each *** study represents a significant contribution to the understanding of intra-annual demographic variation in lizards.

关键词： abundance recruitment Sceloporus lizards survival temporary emigration

Effect of Multipoint Heterogeneity on Nonlinear Transformations for Geological Modeling: Porosity-Permeability relations revisited

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journal of China University of Geosciences 2008年第1期19卷 85-92页

作者： j A vargas-Guzmán Saudi Aramco Dhahran 31311 KSA

An analysis of statistical expected values for transformations is performed in this study to quantify the effect of heterogeneity on spatial geological modeling and evaluations. Algebraic transformations are frequently applied to data from logging to allow for the modeling of geological properties. Transformations may be powers, products, and exponential operations which are commonly used in well-known relations （e.g., porosity-permeability transforms）. The results of this study show that correct computations must account for residual transformation terms which arise due to lack of independence among heterogeneous geological properties. In the case of an exponential porosity-permeability transform, the values may be positive. This proves that a simple exponential model back-transformed from linear regression underestimates permeability. In the case of transformations involving two or more properties, residual terms may represent the contribution of heterogeneous components which occur when properties vary together, regardless of a pair-wise linear independence. A consequence of power- and product-transform models is that regression equations within those transformations need corrections via residual cumulants. A generalization of this result is that transformations of multivariate spatial attributes require multiple-point random variable relations. This analysis provides practical solutions leading to a methodology for nonlinear modeling using correct back transformations in geology.

关键词： reservoir static model intrinsic permeability non-Gaussian nonlinear residual moment cumulant unbiased simulation parameter.

Depth to the bottom of magnetic layer in South America and its relationship to Curie isotherm,Moho depth and seismicity behavior

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Geodesy and Geodynamics 2018年第1期9卷 93-107页

作者： javier Idárraga-garcía Carlos A.vargas research Group on Geophysics Universidad Nacional de ColombiaBogotáColombia Deportment of Geosciences.Universidad Nacional de Colombia.Bogota.Colombia

We have estimated the DBML（depth to the bottom of the magnetic layer） in South America from the inversion of magnetic anomaly data extracted from the EMAG2 grid. The results show that the DBML values, interpreted as the Curie isotherm, vary between -10 and -60 km. The deepest values（〉-45） are mainly observed forming two anomalous zones in the central part of the Andes Cordillera. To the east of the Andes, in most of the stable cratonic area of South America, intermediate values（between -25 and-45 km） are predominant. The shallowest values（〈-25 km） are present in northwestern corner of South America, southern Patagonia, and in a few sectors to the east of the Andes Cordillera. Based on these results, we estimated the heat flow variations along the study area and found a very good correlation with the DBML. Also striking is the observation that the thermal anomalies of low heat flow are closely related to segments of flat subduction, where the presence of a cold and thick subducting oceanic slab beneath the continent, with a virtual absence of hot mantle wedge, leads to a decrease in the heat transfer from the deeper parts of the *** comparing our results with the Moho depths reported by other authors, we have found that the Curie isotherm is deeper than Moho in most of the South American Platform（northward to -20°S）, which is located in the stable cratonic area at the east of the Andes. This is evidence that the lithospheric mantle here is magnetic and contributes to the long wavelength magnetic signal. Also, our results support the hypothesis that the Curie isotherm may be acting as a boundary above which most of the crustal seismicity is concentrated. Below this boundary the occurrence of seismic events decreases dramatically.

关键词： Magnetic layer depth Curie isotherm Heat flow Crustal seismicity Flat subduction South America

relative toxicity of three wheat herbicides to two species of Coccinellidae

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Insect Science 2010年第5期17卷 434-438页

作者： j. P. Michaud German vargas Department of Entomology Kansas State University Hays Kansas USA

On the High Plains of the USA, herbicides specific for broad-leaf weeds are regularly applied to winter wheat in the early spring, sometimes late enough to coincide with the colonization of fields by cereal aphids and their natural enemies. We tested the toxicity of three such herbicides, Ally （Dupont）, rave （Syngenta） and 2,4-D ester （generic）, to neonate larvae of two coccinellid species important in cereal aphid biocontrol, Coleomegilla maculata DeGeer and Hippodamia convergens Gurrin-Mrneville. Topical treatment of larvae with 2,4-D resulted in 25% and 60% mortality in the two species, respectively, with surviving C. maculata larvae experiencing a 5% increase in developmental time. No significant effects were noted for the other two materials, save for a 2.5% increase in developmental time for C. maculata larvae exposed to rave. No material caused significant mortality in either species when larvae were fed on prey （Schizaphis graminum rondani） treated with herbicide 24 h earlier, although 2,4-D reduced developmental time slightly in C. maculata. When herbicide applications are delayed enough in spring to coincide with aphid activity in wheat, farmers can reduce the risk of disrupting biological control by selecting an alternative to 2,4-D.

关键词： 2,4-D Coleomegilla maculata dicamba Hippodamia convergens Schizaphis graminum thifensulfuron methyl

Inflow and outflow permeability tests in a very soft clay under low stresses

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journal of rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3270-3283页

作者： j.W.S.vargas F.A.B.Danziger F.r.Lopes T.Lunne Federal University of rio de janeiro Rio de JaneiroBrazil Norwegian Geotechnical Institute OsloNorway

In situ inflow and outflow permeability tests with the BAT probe at SarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low *** pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the *** role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe *** show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early *** inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading *** sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests *** are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases.

关键词： Permeability test Soft clay BAT probe Inflow and outflow tests

Guest Editorial: Power Systems with Increasing renewable Penetration: Market, Operations, Planning and regulation

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journal of Modern Power Systems and Clean Energy 2021年第4期9卷 I0001-I0002页

作者： Antonio j.Conejo jianhui Wang Angel Arcos vargas Ohio State University ColumbusOhioUSA Southern Methodist University DallasTexasUSA University of Seville SevilleSpain

Our goal in putting together this special section is to contribute to the conversation on control,operations,planning and regulation of power systems with increasing renewable *** a conversation will hopefully involve regulators,operators,producers,consumers,and the research *** hope that this special section will spur innovative ideas that will contribute to ensuring a secure,efficient,and environmentally friendly supply of electrical ener-gy,and to eventually achieve a carbon-free electricity *** special section includes 15 research articles on control,operations,regulation,planning,forecasting,and estimation of power systems with increasing renewable penetration.

关键词： Market operations eventually

Efficiency and effectiveness of systems for the treatment of domestic wastewater based on subsurface flow constructed wetlands in jarabacoa, Dominican republic

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Water Science and Engineering 2024年第2期17卷 118-128页

作者： Yvelisse Pérez Enmanuel vargas Daniel garcia-Cortes William Hernandez Humberto Checo Ulises jauregui-Haza Area de Ciencias Basicas y Ambientales Instituto Tecnologico de Santo Domingo(INTEC)Avenida de Los Proceres 49Los Jardines del NorteSanto Domingo 10602Dominican Republic Ministry of Environment and Natural resources Calle Cayetano Germosen esq.Ave.LuperonEl PedregalSanto Domingo 11107Dominican Republic Plan Yaque Calle Estela Geraldino 14 AltosJarabacoa 41000Dominican Republic Institute of Technologies and Applied Sciences University of HavanaHavana 10400Cuba

Constructed wetlands(CwW)are well known nature-based systems for water *** study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in jarabacoa,the Dominican *** results showed that the CWs were efficient in reducing the degree of contamination of wastewater to levels below the Dominican wastewater discharge standards for parameters such as the 5-day biochemical oxygen demand(BOD5)and chemical oxygen demand,but not for the removal of phosphorus and fecal *** addition,a horizontal flow subsurface wetland in the peri-urban area El Dorado was evaluated in terms of the performance of wastewater treatment in tropical climatic *** concentrations of heavy metals,such as zinc,copper,chromium,and iron,were found to decrease in the effluent of the wetland,and the concentrations for nickel and manganese tended to *** levels of heavy metals in the effluent were lower than the limit values of the Dominican wastewater discharge *** construction cost of these facilities was around 200 USD per population equivalent,similar to the cost in other countries in the same *** study suggested some solutions to the improved performance of CWs:selection of a microbial flora that guarantees the reduction of nitrates and nitrites to molecular nitrogen,use of endemic plants that bioaccumulate heavy metals,combination of constructed wetlands with filtration on activated carbon,and inclusion of water purification processes that allow to evaluate the reuse of treated water.

关键词： Domestic wastewater Constructed wetland BOD COD Pathogens Heavy metals

Investigating lodging in spearmint with overhead sprinklers compared to drag hoses using entropy values from low altitude rGB-imagery

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Information Processing in Agriculture 2022年第2期9卷 335-341页

作者： Behnaz Molaei Abhilash Chandel r.Troy Peters Lav r.Khot juan Quiros vargas Center for Precision and Automated Agricultural Systems Department of Biological Systems EngineeringWashington State University24106 North Bunn RoadProsserWA 99350USA Institute of Bio-and Geosciences Plant Sciences(IBG-2)Forschungszentrum Julich GmbH52428 JulichGermany

Lodging occurs when the crop canopy is too heavy for the strength of the stem and it fallsover onto the ground. This decreases crop yield and quality, and it makes harvest difficult.A research experiment was set up in a spearmint field on a center pivot with mid elevationspray application (MESA) overhead sprinklers, where the water was applied from a “midelevation” of 2 m above the ground level (AGL), and low elevation precision application(LEPA) sprinklers, where the water was emitted directly onto the soil surface through draghoses without wetting the crop canopy. Every-other span of this full-size center pivot wasconfigured with MESA and LEPA sprinklers alternatively. In 2018, imagery was collectedwith an unmanned aerial vehicle (UAV) from a cross section of this field. In 2019, a crosssection was again collected, but in addition UAV imagery was collected from marked lodgedand un-lodged areas of the field to validate the lodging detection method. These UAV-basedimagery data were captured with a ground sample distance (GSD) of 0.03 m. This researchintroduces using the texture feature, which is based on image entropy, was used to evaluate the degree of lodging. The results from 2018 showed that the average entropy of thegrayscale image from LEPA (5.5 (mean) ± 0.27 (standard deviation)) was significantly(P reater than the average entropy (5.0 ± 0.25) of MESA. Also, the entropy valueextracted from the images in 2019 from the marked un-lodged locations were significantlyhigher compared to that of the lodged areas. Overall, the LEPA irrigation treatment was significantly less lodged compared to MESA. Moreover, the entropy value, or texture feature, isa viable method for estimating lodging using low altitude rGB imagery.

关键词： Lodging Spearmint Entropy value Texture feature LEPA and MESA irrigation systems