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Universalities of earthquake-network characteristics

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Chinese Science Bulletin 2011年第34期56卷 3697-3701页

作者： ABE Sumiyoshi PASTN Denisse MUOZ Víctor SUZUKI Norikazu Department of Physical Engineering Mie University Institut Supérieur des Matériaux et Mécaniques Avancés Departamento de Física Facultad de Ciencias Universidad de Chile College of Science and Technology Nihon University

The scale-free and small-world properties are studied in detail for the complex earthquake networks constructed from the seismic data sets taken from California (USA), Japan, Iran and Chile. It is found that, in all these geographical regions, both the exponent / of the power-law connectivity distribution and the clustering coefficient C take the universal invariant values /≈1 and C≈0.85, respectively, as the cell size, which is the scale of coarse graining needed for construction of network, becomes larger than a certain value. A possible physical interpretation is given to the emergence of such remarkable invariance.

关键词：地震网络普遍性加利福尼亚州构造复杂聚类系数地理区域网络建设物理解释

Understanding root-zone soil moisture in agricultural regions of Central Mexico using the ensemble Kalman filter,satellite-derived information,and the ThEXMEX-18 dataset

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International Journal of Digital Earth 2022年第1期15卷 52-78页

作者： héctor Ernesto huerta-Bátiz Daniel Enrique Constantino-Recillas Alejandro Monsiváis-huertero Juan Carlos hernández-Sánchez Jasmeet Judge Ramón Sidonio Aparicio-García Escuela Superior de Ingeniería Mecánica y Eléctrica Unidad Ticomán Instituto Politécnico NacionalMexico CityMexico Escuela Superior de Ingeniería Mecánica y Eléctrica Unidad Zacatenco Instituto Politécnico NacionalMexico CityMexico Tecnológico Nacional de México-TESE EcatepecMexico Department of Agricultural and Biological Engineering University of FloridaGainesvilleFLUSA

An Ensemble Kalman Filter(EnKF)-based assimilation algorithm was implemented to estimate root-zone soil moisture(RZSM)using a Soil-Vegetation-Atmosphere Transfer(SVAT)model during a complete growing season of corn in Central *** and field soil moisture(SM)observations and NASA SMAP SM retrievals were used to understand the effect of vertically spatial updates and uncertainties in meteorological forcings on RZSM *** of RZSM every 3 days using SM observations at 4 depths lowered the averaged standard deviation(ASD)and the root mean square error(RMSE)by 60%and 50%,respectively,compared to the open-loop *** assimilation of synthetic SM at the top 0-5 cm obtained RZSM closer to observations compared to ThEXMEX-18 SM measurements and SMAP SM *** between EnKF estimates and SM observations and SMAP SM retrievals are mainly due to misrepresentation of vegetation *** results improved SM estimates up to 10-cm depth using SMAP SM retrievals;however,additional studies are needed to improve SM at deeper *** implemented methodology can estimate SM at the top 10 cm of the soil every 3 days to mitigate the impact of the climate change on agricultural production over rainfed areas,particularly in developing countries.

关键词： Root-zone soil moisture SVAT model ensemble kalman filter soil moisture active-Passive(SMAP)mission agricultural region ThEXMEX-18 central Mexico

MgO-based adsorbents for CO2 adsorption:Influence of structural and textural properties on the CO_2 adsorption performance

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Journal of Environmental Sciences 2017年第7期29卷 418-428页

作者： Gutiérrez-Bonilla Elvira Granados-Correa Francisco Sánchez-Mendieta Víctor Morales-Luckie Raúl Alberto National Institute of Nuclear Research Department of ChemistryA.P.18-1027Col.EscandonMigud Hidalgo DelegationZip Code 1180 Mexico D.F.Mexico Autonomous University of Mexieo State Faculty of ChemistryColon avenueintersection with ride Tollocan s/n TolucaMexicoMexico

A series of MgO-based adsorbents were prepared through solution–combustion synthesis and ball-milling *** prepared MgO-based powders were characterized using X-ray diffraction,scanning electron microscopy,N_2 physisorption measurements,and employed as potential adsorbents for CO_2 *** influence of structural and textural properties of these adsorbents over the CO_2 adsorption behaviour was also *** results showed that MgO-based products prepared by solution–combustion and ball-milling processes,were highly porous,fluffy,nanocrystalline structures in nature,which are unique physico-chemical properties that significantly contribute to enhance their CO_2 *** was found that the MgO synthesized by solution combustion process,using a molar ratio of urea to magnesium nitrate（2：1）,and treated by ball-milling during 2.5 hr（MgO-BM2.5h）,exhibited the maximum CO_2 adsorption capacity of 1.611 mmol/g at 25℃ and 1 atm,mainly via *** CO_2 adsorption behaviour on the MgO-based adsorbents was correlated to their improved specific surface area,total pore volume,pore size distribution and *** reusability of synthesized MgO-BM2.5h was confirmed by five consecutive CO_2adsorption–desorption times,without any significant loss of performance,that supports the potential of MgO-based *** results confirmed that the special features of MgO prepared by solution–combustion and treated by ball-milling during 2.5 hr are favorable to be used as effective MgO-based adsorbent in post-combustion CO_2 capture technologies.

关键词： CO_2 adsorption MgO-based adsorbents Porous materials Solution–combustion synthesis Ball-milling process Textural properties

Survival and growth of dominant tree seedlings in seasonally tropical dry forests of Yucatan: site and fertilization effects

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Journal of Plant Ecology 2014年第5期7卷 470-479页

作者： Luis Salinas-Peba Víctor Parra-Tabla Julio Campo Miguel A.Munguía-Rosas Departamento de Ecología Tropical Campus de Ciencias Biológicas y AgropecuariasUniversidad Autónoma de YucatánKm.15.5 Carretera Mérida-XmatkuilYucatán 97000México Instituto de Ecología Universidad Nacional Autónoma de MéxicoA.p.70-275México D.F.04510México Departamento de Ecología humana Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional(CINVESTAV)Km.6 Antigua carretera a ProgresoMérida 97310México

Aims Seasonally tropical dry forests of the Yucatan Peninsula are typically found in sites with nutrient-poor soils because of the recent geologi-cal origin of the *** landscape is dominated by extensive karstic plates that shape environments where vegetation regenera-tion through seed germination may be limited by the availability of suitable *** this study,we documented the survival and growth of seedlings from three dominant tree species(Bursera simaruba,Piscidia piscipula and Lysiloma latisiliquum)in seasonally tropical dry forests in ***,we evaluated the effect of nutrient addition(N and P,separately and in combination)on seedling survival and growth across three sites with differing levels of *** We conducted a nutrient addition experiment,whereby we estab-lished 12 plots of dimensions 10×10 m(100 m^(2))at each site,from which three plots were randomly selected to receive one of four treatments:N addition,P addition,N and P addition and no nutri-ent addition(controls).Prior to treatment application,in each plot,we planted 10 seedlings of each species in October 2010 and sub-sequently conducted surveys of plant growth and survival every 20 days from November 2010 to April *** Findings Overall,nutrient addition increased seedling survival and the mag-nitude of this effect was similar among *** did not observe an additive effect of the N+P treatment on ***,we observed a positive effect of nutrient addition on seedling growth,but this effect was contingent upon site;regarding survival,the effects of N and P on seedling growth were not *** results suggest that seedling recruitment and growth in the three dominant species of trees in Yucatan are limited by nutrient avail-ability but that the magnitude of this effect,particularly on seedling growth,is specific for species and site.

关键词： growth nitrogen nutrient addition phosphorus seedling survival seasonally tropical dry forest

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

Removal of Aqueous Lead and Copper Ions by Using Natural hydroxyapatite Powder and Sulphide Precipitation in Cyanidation Process

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Materials Sciences and Applications 2013年第4期4卷 231-237页

作者： José Refugio Parga Jesús Leobardo Valenzuela Víctor Vazquez Mario Rodriguez héctor Moreno Departament of Chemical Engineering and Metallurgy University of Sonora Hermosillo Mexico Department of Chemistry Institute Technology of Laguna Torreon Mexico Department of Metallurgy and Materials Science Institute Technology of Saltillo Saltillo Mexico

Mining, ore processing, and smelting activities have contaminated soil and water resources with cyanide and heavy metals throughout the world. In-situ chemical immobilization is a remediation technology that decreases the concentrations of dissolved ions of copper cyanide and lead hydroxides by adsorption or precipitation. This study deals, with a process to recover lead hydroxides with natural hydroxyapatite powder and copper cyanide ions with sulphide precipitation from solutions of the cyanidation process. This technology is based on inducing nucleated precipitation of copper and silver in a serpentine reactor, using sodium sulfide as the precipitator, and sulfuric acid for ph control. Results show that ph value has a significant effect on copper cyanide removal efficiency, and it was determined the optimal ph range to be 2.5 - 3. At this ph value, the copper cyanide removal efficiency achieved was up to 99% with 60 percent of copper purity and the cyanide ions associated with this complex the recovery was 90%. For the elimination of lead hydroxides ions from the aqueous cyanidation process with natural hydroxiapatite powder the recovery was 99%. The abundance of cow bones, its low price and non-aggressive nature towards the environment are advantages for its utilization in point of view of wastewater cleanup and Dore with higher quality.

关键词： Natural hydroxyapatite Sulphide Precipitation Zinc Cementation

Variable exponent hardy spaces associated with discrete Laplacians on graphs

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Science China Mathematics 2019年第1期62卷 73-124页

作者： Víctor Almeida Jorge J.Betancor AlejANDro J.Castro Lourdes Rodríguez-Mesa Departamento de Análisis Matemático Universidad de La Laguna Department of Mathematics Nazarbayev University

In this paper we develop the theory of variable exponent hardy spaces associated with discrete Laplacians on infinite graphs. Our hardy spaces are defined by square integrals, atomic and molecular decompositions. Also we study boundedness properties of Littlewood-Paley functions, Riesz transforms, and spectral multipliers for discrete Laplacians on variable exponent hardy spaces.

关键词： graphs discrete Laplacian hardy spaces variable exponent square functions spectral multipliers

Detection of integron integrase genes on King George Island, Antarctica

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Advances in Polar Science 2015年第1期26卷 30-37页

作者： Verónica Antelo héctor Romero Silvia Batista Unidad de Microbiología Molecular Biogem Instituto de Investigaciones Biológicas Clemente Estable (MEC) Departamento de Ecología y Evolución Facultad de Ciencias UDeLaR Montevideo C.P.11400 Uruguay

The presence and diversity of class 1 integrase gene （intl） sequences were evaluated by PCR using previously designed primers. Two clone libraries were constructed from DNA in sediment and microbial mat samples collected on Fildes Peninsula, King George Island, *** libraries constructed from samples collected at halfthree Point （hP） and Norma Cove （NC） contained 62 and 36 partial intl sequences, respectively. These sequences clustered into 10 different groups with 〈 95% amino acid identity. Alignment of the deduced amino acid sequences with those from recognized integron-encoded integrases demonstrated the presence of highly conserved motifs characteristic of intl integrases. The hP library contained 42 nucleotide sequences identical to the class 1 intl gene found in a collection of trimethoprim-resistant （Tmpr） Antarctic Enterobacter sp. isolates, previously collected in the same area. These integrons, located on plasmids, had a genetic organization similar to that of pKOX105 from Klebsiella oxytoca. The 20 remaining hP and NC library sequences were similar to integrase sequences previously determined in a metagenomic analysis of environmental samples. We have demonstrated the presence of integron integrase genes in Antarctic sediment samples. About half these genes were very similar to the class 1 integrons found in human- associated microbiota, suggesting that they originated from human-dominated ecosystems. The remaining integrase genes were probably associated with endemic bacteria.

关键词： integrase amplicon library maritime Antarctica

Complementary examinations other than neuroimaging and neurosonology in acute stroke

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World Journal of Clinical Cases 2017年第6期5卷 191-202页

作者： Adrià Arboix Víctor Obach Maria José Sánchez Joan Massons Cerebrovascular Division Department of Neurology Hospital Universitari del Sagrat Cor University of Barcelona Acute Stroke Unit Department of Neurology Hospital Clínic University of Barcelona

The etiologic diagnosis of cerebrovascular diseases requires non-routine complementary examinations to be performed. Thus, in specific cases, after neuroimaging(computed tomography/magnetic resonance imaging cerebral scan sequences) and neurosonology(Doppler test of the supra-aortic trunks, transcranial echography and echocardiography), which academically allow us to classify the patients according to their etiologic stroke subtype, further examinations must be used to make a correct etiologic diagnostic. The present review aims to update knowledge about the usefulness of the different tests of blood and urine, plain chest radiography, X-ray of the spine, skull and abdomen, lumbar puncture, electroencephalography, evoked potentials, polysomnography, and pathologic examination after biopsy of the artery, skin, muscles, nerves, meninges, and brain, in the management of patients who have suffered an acute stroke.

关键词： Complementary examinations Cerebrovascular disorders Acute stroke Diagnostic techniques Blood biochemistry Polysomnography