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阿尔卑斯山南部与欧洲地学断面交会地区的地壳结构

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地球物理学进展 1987年第1期 39-52页

作者： n.deichmann J.Ansorge St.Mueller 熊绍柏

根据1977年阿尔卑斯山南部的一系列折射试验资料,最近重新绘制了可控振幅的数字化记录剖面。这使我们可以对伦巴第(Lombardy)西部与Giudicaria断层之间地区的地壳结构重新进行解释。所得到的模型表明有相当大的横向不均匀性:在西部,7.5k... 详细信息

根据1977年阿尔卑斯山南部的一系列折射试验资料,最近重新绘制了可控振幅的数字化记录剖面。这使我们可以对伦巴第(Lombardy)西部与Giudicaria断层之间地区的地壳结构重新进行解释。所得到的模型表明有相当大的横向不均匀性:在西部,7.5km厚的伦巴第盆地沉积层之下,地壳厚度只有31km;而向东部的多山地区,地壳增厚,在Adamello地块之下,达到46km.尽管相应的反射波信号特征稍微有些不稳定,但这些资料足以确定上地壳中的一个低速区,在大约20km深处的中地壳内还发现一个小的速度间断面,其速度值从6.2变为6.4km/s.过去只根据走时资料解释,认为在这个深度上有一个速度大约为7km/s的层。这个高速层曾被解释为是阿尔卑斯造山运动时期逆冲到欧洲板块之上的亚得里亚—非洲板块的下地壳物质,以此来解释阿尔卑斯山南部地区的隆起。然而,这种双重地壳的模型是有问题的,因为这样一个中地壳内的高速层与振幅资料不符。根据地质方面的证据,伦巴第盆地下方地壳中较薄的结晶部分被解释为是晚海西期一个裂谷事件的遗迹。

关键词：地学断面地壳结构阿尔卑斯山测线测网炮点非洲板块结晶基底地台基底阿尔卑斯造山运动里阿斯统伦巴第沉积盆地欧洲

观测到的小震与大震之间M_L/M_W标度突然改变的理论基础

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世界地震译丛 2019年第1期50卷 1-20页

作者： n.deichmann 杨国栋(译) 曾文浩(译) 许忠淮(校) 不详甘肃省地震局中国地震局地球物理研究所

对完全弹性介质中的一组地震,如果应力降和破裂速度不随震级系统变化,进行仪器响应校正后,在可以确定M_L的整个范围内,M_L∝M_W。然而,实际上我们观察到,M_L和M_W偏离了1:1的标度关系。天然地震序列和诱发地震活动实例的详细分析结果表... 详细信息

对完全弹性介质中的一组地震,如果应力降和破裂速度不随震级系统变化,进行仪器响应校正后,在可以确定M_L的整个范围内,M_L∝M_W。然而,实际上我们观察到,M_L和M_W偏离了1:1的标度关系。天然地震序列和诱发地震活动实例的详细分析结果表明:对小地震(通常M_W小于2~3),M_L∝1.5 M_W,这和其他研究结果一致。由独立测定若干Q值确定的因果算子Q和合成地震震源时间函数褶积可以再生这一比例关系。数据分析和模拟试验的一个重要结果是,观察到的低于某一确定震级的小地震的脉冲宽度及其相应的拐角频率实际上是不变的。因此,在衰减介质中,小地震信号本质上构成了由地震矩来量度其尺度的介质的脉冲响应。简单的理论分析结果表明,在这种情况下,观察到的M_L和M_W之间的比例系数1.5是矩率函数振幅和持续时间对地震矩固有标度特征和衰减介质频率响应的自然结果。因为这个结果和伍德—安德森地震仪响应对大地震引入的偏差,基于M_L的古登堡—里克特关系失去了物理上的合理性,相对于M_W导致了大地震和小地震不同的b值。

关键词：标度关系震源时间函数弹性介质基础大震小震观测小地震

Chebyshev polynomial-based Ritz method for thermal buckling and free vibration behaviors of metal foam beams

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 891-910页

作者： n.D.nGUYEn T.n.nGUYEn Faculty of Civil Engineering Ho Chi Minh City University of Technology and EducationHo Chi Minh City 71309Viet Nam Faculty of Engineering and Technology Kien Giang UniversityChau Thanh 92000Viet Nam

This study presents the Chebyshev polynomials-based Ritz method to examine the thermal buckling and free vibration characteristics of metal foam *** analyses include three models for porosity distribution and two scenarios for thermal *** material properties are assessed under two conditions,i.e.,temperature dependence and temperature *** theoretical framework for the beams is based on the higher-order shear deformation theory,which incorporates shear deformations with higher-order *** governing equations are established from the Lagrange equations,and the beam displacement fields are approximated by the Chebyshev *** simulations are performed to evaluate the effects of thermal load,slenderness,boundary condition(BC),and porosity distribution on the buckling and vibration behaviors of metal foam *** findings highlight the significant influence of temperature-dependent(TD)material properties on metal foam beams'buckling and vibration responses.

关键词： Ritz method Chebyshev function buckling vibration metal foam beam higher-order beam theory(HOBT)

Compression properties of cost-efficient porous expanded clay reinforced AA7075 syntactic foams fabricated by industrial-oriented die casting technology

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China Foundry 2024年第1期21卷 60-70页

作者： İsmail Cem Akgün Çağın Bolat Ali Gökşenli Faculty of Mechanical Engineering Istanbul Technical University34437İstanbulTurkey Faculty of Engineering Samsun University55420SamsunTurkey

In today’s manufacturing industries,hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and *** this point,aluminum syntactic foams(ASFs)are new-generation engineering composites and come into the upfront as a *** to their features like low density,sufficient elongation,and perfect energy absorption ability,these advanced foams have been considerably seductive for many industrial sectors *** this study,an industrial-oriented automatic die casting technology was used for the first time to manufacture the combination of AA7075/porous expanded clay(PEC).Micro evaluations(optical and FESEM)reveal that there is a homogenous particle distribution in the foam samples,and inspections are compatible with the other ASF ***,T6 aging heat treatment was operated on one half of the produced foams to explore the probable impact of aging on the compressive *** results show that PEC particles can be an alternative to expensive hollow spheres used in the previous ***,a favorable relationship is ascertained between the aging treatment and mechanical properties such as compression strength and plateau strength.

关键词： die casting porous materials metal matrix sytanctic foams expanded clay compressive deformation

Towards defining soil quality of Mediterranean calcareous agricultural soils:Reference values and potential core indicator set

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International Soil and Water Conservation Research 2024年第1期12卷 145-155页

作者： Germán A.Durán Daniel Sacristán Edelweis Farrús Jaume Vadell Institut de Recerca i FormacióAgrària i Pesquera de les Illes Balears C/Eusebi Estada14507009PalmaSpain Plant Biology Department University of Valencia46100BurjassotValenciaSpain Soil and Environmental Quality Department Centro de Investigaciones sobre Desertificación-CIDE(CSIC-Universitat de València-Generalitat Valenciana)Carretera Moncada-Náquera km 4.546113MoncadaValenciaSpain Universitat de les Illes Balears Cra.De Valldemossakm 7507122PalmaSpain

To avoid soil degradation,adapt to climate change and comply with the Sustainable Development goals 2030(Un General Assembly),establishing the quality/fertility of the agricultural soils of the Mediterranean region and evaluate how these evolve with time is *** enables adequate management practices to be *** Mediterranean calcareous region has received little attention in this sense,in spite its soil ***,24 different representative calcareous agricultural soils of the Mediterranean region,including the main management strategies of agricultural soils(rainfed and irrigated),were sampled from the island of Mallorca;and their physical,chemical and biological properties *** values obtained for most of the soil characteristics allowed to establish an initial approach to the reference values for the type of calcareous agricultural soils considered,and to clearly distinguish the effect of rainfed or irrigation management practices on soils properties and *** enzyme activities were not stimulated by the irrigation conditions assayed or they were only in dry conditions,suggesting optimum enzyme activities could be obtained when alternating dry and humid soil *** organic carbon,calcium carbonate and active lime revealed of significant importance in the collection of ***,the results obtained clearly indicate the heterogeneity of the region and its implications on the different soil ***,this study could serve as a starting point to adequately establish the quality(fertility)for Mediterranean calcareous agricultural soils and their reference values by conducting further research in this region and including more type of soils.

关键词： Soil fertility Mediterranean agricultural soils Calcareous soils Soil enzymes Soil management

Weather influenced nestling growth of an insectivorous but not a granivorous grassland passerine in Argentina

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Avian Research 2024年第2期15卷 156-162页

作者： Martín Alejandro Colombo Adrian Jauregui Luciano n.Segura Laboratorio de Ecología de Aves.Institute“Dr.Raúl A.Ringuelet”(ILPLA)-UnLP/COnICET Boulevard 1201437La PlataB1900Buenos AiresArgentina

nestling growth of birds can be affected by weather *** general,it is expected that higher temper-atures favor growth by improving food availability and nestling metabolism,while rain hinders it by reducing foraging ***,most of these patterns have been described in insectivorous cavity-nesting birds in temperate *** tested these predictions in two neotropical grassland ground-nesting birds with contrasting nestling diets and therefore potentially different responses to *** measured nestlings of the Hellmayr’s Pipit(Anthus hellmayri,an insectivorous passerine)and the Grassland Yellow-Finch(Sicalis luteola,which feeds its nestlings exclusively with seeds)during three breeding seasons(2017-2020)in central-eastern *** took measurements of tarsus and body mass,modeled growth curves using nonlinear mixed-effects models,and evaluated the effects of minimum daily temperature and precipitation during the growth period and the 30 days prior to *** pipits(60 nestlings from 21 nests),minimum temperatures during the growth period were positively associated with tarsus and body mass ***,there was a positive association between precipitation during the pre-hatching period and tarsus ***,none of the weather variables analyzed had significant effects on nestling growth of finches(131 nestlings from 35 nests).Dietary contrast between species may explain the different *** activity and abundance can be affected by weather variations within the span of a breeding season,whereas seeds may depend on conditions from previous years,making the effects harder to *** with reduced asymptotic size can have reduced chances of ***,pipit populations could be impacted if they experience cold and dry conditions during their breeding season,which is of major relevance in the current context of climate change.

关键词： Finches Grassland birds neotropical birds Pipits Precipitation Temperature

Marinoan glaciation in the Indian subcontinent——Anatomy and global implications

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Journal of Palaeogeography 2024年第2期13卷 293-308页

作者： H.n.Bhattacharya Department of Earth Sciences Techno India UniversityWest BengalSector VSalt LakeKolkata700091India

Detailed sedimentological analysis of the Pokaran Boulder Bed,representing the most basal unit of the neoproterozoic-Lower Cambrian Marwar Supergroup,clearly indicates its glacial *** glacial sediments are interpreted as an ice-contact submarine fan *** on the detrital and inherited zircon population of the Marwar Supergroup sediments and interlayered pyroclastic deposits,a Marinoan cryochron of the Cryogenian Period is envisaged for the Pokaran Boulder *** well-preserved Ediacaran elements in the post-glacial sedimentary succession also support a Cryogenian to Early Cambrian age of the Marwar *** glacial deposition at the base of the Marwar Supergroup strengthens the regional correlation between the studied sediments with the Lesser Himalayan Blaini-Krol-Tal sediments and the Haqf Supergroup of *** available zircon ages and paleomagnetic data of the Malani Igneous suite,along with the Marinoan glacial deposits,detrital zircon ages,and Ediacaran fossil elements of the Marwar Supergroup add significant information to the neoproterozoic Earth history.

关键词： neoproterozoic Marinoan glaciation Diamictites Pokaran Boulder Bed Marwar Supergroup

5-Bromo-2'-deoxyuridine labeling:historical perspectives,factors infiuencing the detection,toxicity,and its implications in the neurogenesis

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neural Regeneration Research 2024年第2期19卷 302-308页

作者： Joaquín Martí-Clúa Unidad de Citología e Histología.Departament de Biologia Cel·lular de Fisiologia i d’Immunologia.Facultad de Biociencias.Institut de Neurociències.Universidad Autónoma de Barcelona08193 BellaterraBarcelonaSpain

The halopyrimidine 5-bromo-2′-deoxyuridine(BrdU)is an exogenous marker of DnA *** the introduction of monoclonal antibodies against BrdU,an increasing number of methodologies have been used for the immunodetection of this synthesized bromine-tagged base analogue into replicating *** labeling is widely used for identifying neuron precursors and following their fate during the embryonic,perinatal,and adult neurogenesis in a variety of vertebrate species including birds,reptiles,and *** to BrdU toxicity,its incorporation into replicating DnA presents adverse consequences on the generation,survival,and settled patterns of *** may lead to false results and misinterpretation in the identification of proliferative *** this review,I will indicate the detrimental effects of this nucleoside during the development of the central nervous system,as well as the reliability of BrdU labeling to detect proliferating ***,it will show factors influencing BrdU immunodetection and the contribution of this nucleoside to the study of prenatal,perinatal,and adult *** adult neurogenesis will also be *** is my hope that this review serves as a reference for those researchers who focused on detecting cells that are in the synthetic phase of the cell cycle.

关键词： 5-bromo-2′-deoxyuridine adult neurogenesis human adult neurogenesis labeling pitfalls prenatal neurogenesis proliferation S-phase suturing S-phase toxicity

Influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 563-580页

作者： n.HUMnEKAR D.SRInIVASACHARYA Department of Mathematics National Institute of TechnologyWarangal 506004TelanganaIndia

The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is *** DarcyBrinkman model is used to characterize the fluid flow dynamics in porous *** analytical solutions are obtained for the unidirectional and completely developed *** on a normal mode analysis,the generalized eigenvalue problem under a perturbed state is *** eigenvalue problem is then solved by the spectral ***,the critical Rayleigh number with the corresponding wavenumber is evaluated at the assigned values of the other flow-governing *** results show that increasing the Darcy number,the Lewis number,the Dufour parameter,or the Soret parameter increases the stability of the system,whereas increasing the inclination angle of the channel destabilizes the ***,the flow is the most unstable when the channel is vertically oriented.

关键词： nanofluid inclined channel variable viscosity linear stability double dif-fusion porous medium