检索结果-南通市图书馆

HVSR analysis of pumice sands for sediment depth characterization:A case study for Guadalajara,Mexico

Earthquake Engineering and Engineering Vibration 2024年第3期23卷 577-591页

作者： Hafid Salgado M. Alejandro Ramírez-Gaytan Adolfo Preciado Christian R.escudero Departamento de Ciencias Exactas Centro Universitario de la CostaUniversidad de GuadalajaraCP.48280 Puerto VallartaJaliscoMéxico Departamento de Ciencias Computacionales Centro Universitario de Ciencias Exactas e IngenieríaUniversidad de GuadalajaraCP.44430 GuadalajaraJaliscoMéxico Departamento del Hábitat y Desarrollo Urbano Instituto Tecnológico y de Estudios Superiores de Occidente(ITESO)CP.45604 TlaquepaqueMéxico

The horizontal to vertical spectral ratio(HVSR)methodology is used here to characterize pumice soils and to image the three-dimensional surface geometry of Guadalajara,*** to other Latin American cities,Guadalajara is exposed to high seismic risk,with the particularity of being the largest urban settlement in Latin America built on pumice *** has not yet been tested to characterize subsoil depths in pumice *** to the questionable use of traditional geotechnical tests for the analysis of pumice soils,HVSR provides an alternative for its characterization without altering its fragile and porous *** this work,resonance frequency(F0)and peak amplitude(A0)are used to constrain the depth of the major impedance contrast that represents the interface between bedrock and pumice *** were compared with borehole depths and other available geotechnical and geophysical data and show good *** of the profiles estimated on the riverbanks that cross the city,reveals different subsoil thickness that could have an impact on different site responses on riverine areas to an eventual *** and academic efforts are combined in this work to characterize depth sediments,an important parameter that impacts the regulations for construction in the city.

关键词： subsoil of Guadalajara shallow soil thickness bedrock depth pumice soil characterization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fibonacci Sequences and the Multiperiodicity of the Variable Star UW Herculis

引用

Chinese Journal of Astronomy and Astrophysics 2003年第3期3卷 235-240页

作者： Juan Garcia escudero Departamento de Fisica Universidad de Oviedo 33007 Oviedo Spain

We present an application of the methods recently developed for the study of quasicrystal structures to the analysis of multiperiodicity of semiregular variables. A light curve analysis of UW Her shows frequencies that can be included within the general scheme characterizing the Fourier spectra of Fibonacci quasiperiodic sequences. The analysed data come from the BAA Variable Star Section computerised archive.

关键词： stars: variables

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Plant ontogenetic changes in vein and stomatal traits and their relationship with economic traits in leaves of three Mediterranean oaks

引用

Journal of Plant Ecology 2021年第6期14卷 1090-1104页

作者： Sonia Mediavilla Ignacio Martin Alfonso escudero Area de Ecologia Facultad de BiologiaUniversidad de SalamancaCampus Miguel de UnamunoSalamanca 37007Spain Dpto.de Botanica y Fisiologia Vegetal Facultad de BiologiaUniversidad de SalamancaCampus Miguel de UnamunoSalamanca 37007Spain

Aims We compared vein and stomatal traits of seedlings and adults of three Mediterranean Quercus *** work suggests that gas-exchange rates tend to be higher at the seedling stage than in *** objective was to determine whether vein and stomatal traits vary throughout whole-plant ontogeny in parallel with the changes in gas-exchange *** addressed the following alternative hypotheses:hypothesis 1—seedlings show higher vein and stomatal densities than adults;and hypothesis 2—seedlings have lower investments in vascular tissues to reduce construction *** Ten specimens from each growth stage were randomly sampled for each species in a location in central-western *** measured mean stomatal and vein traits(size and number of stomata per unit of leaf area,vein density,vein volume,vein to epidermis distance),leaf mass per area and lamina *** Findings Minor vein density and vein volume per area increased with tree age,which seems inconsistent with the ontogenetic trends in gas-exchange *** discrepancy is in support of our hypothesis 2,and it suggests that,at the seedling stage,reducing investments in vascular tissues in benefit of maximizing growth rates is a *** interveinal distances in seedlings were compensated by smaller vein to epidermis *** thin leaves of the seedlings may thus constitute as a necessary trait for achieving shorter path length distances for the transport of water to evaporation sites without the need for a strong investment in costly vascular tissues.

关键词： leaf venation leaf life span plant ontogenetic changes Quercus species stomatal traits

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Phase Transformation under Continuous Cooling Conditions in Medium Carbon Microalloyed Steels

引用

Journal of Materials Science & Technology 2014年第5期30卷 511-516页

作者： Manuel Gomez Lucia Rancel Esther escudero Sebastian F.Medina National Centre for Metallurgical Research CENIM-CSICAv.Gregorio del Amo 828040 MadridSpain

Several 35CrMo4 and 38MnV7 steels with different additions of Ti and V were manufactured by electroslag remelting. The influence of the alloying and microalloying elements on phase transformation at different cooling rates was studied and the continuous cooling transformation diagrams were plotted. In order to optimize the heat treatment and improve the mechanical properties, the range of cooling rates leading to a fully bainitic microstructure （without ferrite, pearlite and especially without martensite） was determined. Bainite and martensite transformation start temperatures （Bs, Ms） were also established and compared with the values predicted by empirical equations. The important role of precipitates （especially V carbonitride particles） on final microstructure and mechanical properties was assessed.

关键词： Microalloyed steel Phase transformation Precipitation Dilatometry Continuous cooling transformation diagram

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Premature losses of leaf area in response to drought and insect herbivory through a leaf lifespan gradient

引用

Journal of Forestry Research 2022年第1期33卷 39-50页

作者： Sonia Mediavilla Montserrat Martínez-Ortega Santiago Andrés Javier Bobo Alfonso escudero Departamento de Ecología Facultad de BiologíaUniversidad de Salamanca37071 SalamancaSpain Departamento de Botánica y Fisiología Vegetal Facultad de BiologíaUniversidad de Salamanca37071 SalamancaSpain

Implications of the differences in leaf life span are still subject to debate in the field of *** leaf traits associated with these differences may be decisive for determining the distribution of tree species,this topic is particularly relevant in the context of climate *** study analyzes the effects of the differences in leaf life span on premature losses of leaf area owing to insect herbivory and to abiotic *** of leaf area may be an important determinant of total leaf carbon *** Mediterranean tree species,distributed on four sites with different climates were *** species exhibited strong differences in leaf life span and in leaf traits,especially leaf mass per unit *** leaf area losses were estimated in response to insect herbivory and summer drought over two *** results revealed that,despite having older leaf cohorts with more damage,species with longer leaf duration had lower area lost to herbivores and less damage due to accelerated senescence during the summer *** respect to the predicted increase in water stress,deciduous species are at a disadvantage due to their high premature loss of leaf area and thus loss of photosynthetic capacity.

关键词： Accelerated senescence Insect herbivory Leaf life span Leaf structural reinforcement Summer drought

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Therapeutic potential of insulin-like growth factor 2 in Huntington's disease: controlling proteostasis to alleviate the load of misfolded protein

引用

Neural Regeneration Research 2021年第8期16卷 1564-1565页

作者： Paulina Troncoso-escudero Claudio Hetz Rene L.Vidal Biomedical Neuroscience Institute Faculty of MedicineUniversity of ChileSantiagoChile Center for Geroscience Brain Health and MetabolismSantiagoChile Program of Cellular and Molecular Biology Institute of Biomedical SciencesUniversity of ChileSantiagoChile Center for Integrative Biology Faculty of SciencesUniversity MayorChile Buck Institute for Research on Aging NovatoCAUSA

Huntington's disease(HD) is an inherited autosomal dominant neurodegenerative disorder characterized by the development of adult-onset motor dysfunction,psychiatric disturbances and intellectual *** is associated with an expansion of CAG repeat sequence in the huntingtin gene(Htt).Exon 1 of Htt normally contains between 6 to 35 CAG repeats,whereas in patients affected with HD it contains more than 40 trinucleotides.

关键词： Huntington Therapeutic stasis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ontogenetic transition in leaf traits: a new cost associated with the increase in leaf longevity

引用

Journal of Plant Ecology 2014年第6期7卷 567-575页

作者： Sonia Mediavilla Maria Herranz Patricia González-Zurdo Alfonso escudero Departamento de Ecología Facultad de BiologíaUniversidad de SalamancaSalamanca 37071Spain

Aims Recent work has identified a worldwide‘economics’spectrum of correlated leaf traits that mainly reflects the compromises between maximizing leaf longevity and short-term ***,during the early stages of tree growth different species tend to exhibit a common strategy,because competition for soil water and nutrients forces the maximization of short-term productivity owing to the need for rapid growth during the most vulnerable part of the tree’s life ***,our aim here was to compare the variations that occur during ontogeny in the different leaf traits(morphology and leaf chemical composition)of several coexisting Mediterranean woody species differing in their leaf life spans and to test our hypothesis that tree species with a long leaf life span should exhibit larger shifts in leaf characteristics along *** Six Mediterranean tree species differing in leaf life span,selected from three plots located in central-western Spain,were studied during three growth stages:seedlings,juveniles and mature *** life span,leaf morphology(leaf area,dry weight,thickness and mass per unit area)and chemical composition(N and fibre con-centrations)were measured in all six *** magnitude of the ontogenetic changes in the different traits was estimated and related to the mean leaf longevity of the different *** Findings Along ontogeny,strong changes were observed in all variables *** early growth stages showed lower leaf thickness,leaf thickness and mass per unit area and N,cellulose and hemi-cellulose concentrations than mature trees,but a higher lignin ***,these changes were especially marked in species with a longer leaf life span at *** dif-ferences in leaf life span,leaf morphology and chemical com-position were stronger at the mature stage than at the seedling *** conclude that greater plasticity and more intense strat-egy shifts along ontogeny are necessarily associ

关键词： leaf morphology leaf N concentration fibre content Pinus Quercus tree age class

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The assembly of plant-patch networks in Mediterranean alpine grasslands

引用

Journal of Plant Ecology 2020年第3期13卷 273-280页

作者： David S.Pescador José María Iriondo Gianalberto Losapio Adrián escudero Departamento de Biología y Geología Física y Química InorgánicaEscuela Superior de Ciencias Experimentales y TecnologíaUniversidad Rey Juan CarlosMóstolesSpain Department of Environmental Systems Science ETH ZurichZurichSwitzerland Department of Biology Stanford UniversityStanfordCAUSA

Aims Harsh environmental conditions in alpine ecosystems shape vegetation structure into patches,where many different plant species cluster and grow ***,which factors are important for the structure and dynamics of such plant–patch networks remains poorly *** aim to assess which and how environmental and biotic factors predict the assembly of plant–patch networks along a mountain *** We examined the distribution of plant species in more than 5500 vegetation patches in 37 Mediterranean alpine grasslands distributed along a 500 m altitudinal gradient(National Park of Sierra Guadarrama,Spain).We established a plant–patch network for each grassland community and analyzed how nestedness and modularity vary with environmental(altitude,insolation and soil conditions)and biotic factors(number of species per plot,mean patch area and total pasture area).Important Findings Plant–patch networks showed consistent,non-random patterns characterized by a nested,but not modular,structure,which suggests that positive associations among co-occurring specialists promote their growth within patches as subsets of a pool with more generalist *** nestedness and modularity of plant–patch networks varied among ***,nestedness decreased with increasing species per plot and increased with mean patch area,while it was independent of environmental variables;modularity increased with increasing pasture area and species per *** negative relationship between species per plot and nested patterns may be linked to the restricted number of species that can coexist within the same patch at a given ***,the positive relationship between patch size and nestedness indicates that the growth of rare plant species within vegetation patches occupied by more abundant species is facilitated in bigger rather than smaller ***,these results indicate that the nested assembly of vegetation patches may be independent of abiotic cond

关键词： alpine ecosystems community assembly ecological networks metacommunity modularity nestedness patch dynamics

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Characterization of the Xenopus homolog of animmediate early gene associated with cell activation: sequence analysis and regulation of its expression by thyroid hormone during amphibian metamorphosis

引用

Cell Research 1997年第2期7卷 179-193页

作者： vivia CT LIANG TIFFANY SEDGWICK YUN BOSHI(Laboratory of Molecular Embryology NICHD/NIH, Bldg.18T, Rm. 106 Bethesda, MD 20892-5431 USA) Laboratory of Molecular Embryology NICHD/NIH USA

The complex transformation of a tadpole to a frogduring amphibian development is under the control of thyroid hormone (T3). T3 is known to regulate gene transcription through its nuclear receptors. We have previouslyisolated many genes which are up-regulated by T3 in theintestine of Xenopus laevis tadpoles. We have now cloneda full- length cDNA for one such gene (IU12). Sequenceanalysis shows that the IU12 cDNA encodes a plasmamembrane protein with 12 transmembrane domains andhomologous to a mammalian gene associated with cell activation and organ development. Similarly, we have foundthat IU12 is activated during intestinal remodeling whenboth cell death and proliferation take place. Furthermore,IU12 is an early T3-response gene and its expression in theintestine during T3-induced metamorphosis mimics thatduring normal development. These results argue for a roleof IU12 in the signal transduction pathways leading to intestinal metamorphosis.

关键词： Thyroid hormone Xenopus laevis cell proliferation organogenesis transcription factor

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Analyses of head and thorax in Eupomphini(Meloidae)suggest that complex behaviors are not associated to changes in general shape

引用

Integrative Zoology 2023年第5期18卷 949-957页

作者： Mario GONZÁLEZ-FERREIRO Mario GARCÍA-PARÍS Lucía SAINZ-escudero E.Karen LÓPEZ-ESTRADA Museo Nacional de Ciencias Naturales(MNCN-CSIC) MadridSpain Real Jardín Botánico(RJB-CSIC) MadridSpain

INTRODUCTION Evolution of behavioral responses is often dependent on the existence of modified structures that enable the development of the behavioral suite(Kay 1978;Lundrigan 1996;Alfaro et al.2004;Goyens et al.2015;Higham et al.2015;Sharp et al.2018;Schendel et al.2019).Occasionally,structural modifications are so important that a direct link between morphology and behavior can be inferred(Fleagle 1977;Rodman 1979;Losos 1990a;Higham et al.2015).

关键词： enable structural behaviors

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：