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Taenidium barretti ichnofabric and rainfall seasonality:Insights into dryland suites of Scoyenia ichnofacies

Journal of Palaeogeography 2023年第1期12卷 28-49页

作者： Diego Luciano Nascimento Renata Guimaraes Netto Alessandro Batezelli francisco sergio bernardes ladeira Daniel Sedorko ICHNOS Research Group Geology Graduate ProgramUnisinos UniversityAv.Unisinos95010 Sao LeopoldoRS93022-750Brazil Campinas State University Geology and Natural Resources DepartmentZeferino Vaz University CityBarao GeraldoCampinasSP13083-970Brazil Laboratory of Pedology(LABPED) Department of GeographyGeosciences InstituteGeosciencesState University of CampinasCampinasSP13083-855Brazil Museu Nacional Departamento de Geologia e PaleontologiaUniversidade Federal do Rio de Janeiro.Horto BotanicoParque Quinta da Boa VistaR.Gen.Herculano Gomes1340Sao CristovaoRio de JaneiroRJ20940-040Brazil

The present work analyzes the monotypic Taenidium barretti ichnofabric developed in abandoned channels and floodplains to understand its paleoecological significance in highly seasonal fluvial *** data come from the Cretaceous paleosols of the Marília Formation(Bauru Basin,SE Brazil),in which the *** ichnofabric and rhizoliths represent the biotic *** larvae are considered to be the most likely *** tracemakers in these *** intensity and recurrence of bioturbation suggest that the windows of opportunity for beetle population growth were very short and controlled by the progressive substrate desiccation after flood *** characteristics of the trace fossil assemblage suggest soil colonization by r-strategic organisms triggered by flooding events that provided the resource inputs necessary for their living during rainy *** results also show that in fluvial systems with high discharge variations,the boundaries between a“pre-desiccation suite”and a“desiccation suite”in the Scoyenia ichnofacies can be diffuse due to the short duration of colonization windows and progressive terrestrialization of floodplains and ***,the frequency of flooding events,the lowered water table,and the rapidity of substrate desiccation constrained colonization by other burrowers and may be considered as firstorder factors controlling the generation of a monotypic *** ***,the monotypic Taenidium ichnofabric in the Scoyenia ichnofacies context is an ichnomarker of brief windows for colonization in highly seasonal environments.

关键词： Ichnology Paleopedology Continental ichnofacies Meniscate burrows Ichnofabric

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Stress tensors and quantification of fracture patterns to analyze connectivity and potential fluid flow in a mesa landform of the Northern Andes

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Journal of Mountain Science 2024年第1期21卷 271-291页

作者： GARCÍA-ARIAS sergio VELANDIA francisco ALVAREZ Angélica SANABRIA-GÓMEZ JoséD TARAZONA Yessenia VARGAS María Camila Escuela de Geología Universidad Industrial de SantanderCra.27 Calle 9BucaramangaColombia Escuela de Física Universidad Industrial de SantanderCra.27 Calle 9BucaramangaColombia

This work applies stress tensors inversions and quantification of fracture patterns along the Mesa de Los Santos, in the Eastern Cordillera of Colombia, to better understand the potential fluid flow. It thus contributes to the conceptual hydrogeological model. The area was subdivided into three blocks, separated by the NW Potreros and the Los Santos faults, having minor inner faults of different orientations. This separation facilitates the analysis of the fractures measured in the field, which in general show high dip angles and a conjugate geometry in the northern block, tension fractures(Mode I) in the central block, and a random distribution in the southwestern block. WinTensor treatment of slickensides yielded a maximum horizontal stress(SHmax) of 111o, which coincides with the WNW-ESE tensor observed from the conjugate and tension joints. We then used Frac Pa Q to generate interpolation maps of fracture intensity and density. The maps show the highest values in the central block and the lowest in the northern block,where the precipitation is higher, causing intensive rock weathering and homogenization of the fracture planes. Although the highest values of connectivity by line are found to the south of the mesa, we suggest the possibility of greater flow from the recharge zone(NE) along bedding planes and open NW-SE fractures.

关键词： Mesa de Los Santos Colombia Win-Tensor FracPaQ Strike-slip faults Fractured aquifers

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Decoupled Photovoltaic Power Ramp-rate Calculation Method for Perturb and Observe Algorithms

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Journal of Modern Power Systems and Clean Energy 2022年第4期10卷 932-940页

作者： Jose Miguel Riquelme-Dominguez francisco M.Gonzalez-Longatt sergio Martinez Electrical Engineering Department Escuela Tecnica Superior de Ingenieros IndustrialesUniversidad Politecnica de Madrid28006 MadridSpain Department of Electrical Engineering Information Technology and CyberneticsUniversity of South-Eastern Norway3918 PorsgrunnNorway

As photovoltaic energy increasingly penetrates in power systems,transmission system operators have started to request its participation in providing ancillary *** of the demanded services is the power ramp-rate control(PRRC),which attempts to limit the power ramps produced by intermittent irradiance *** order to achieve the desired objective,solutions based on storage systems or modifying the maximum power point tracking(MPPT)in perturb and observe(P&O)algorithms are commonly *** starting point in PRRC is the determination of the instantaneous power ramprate,and different methods have been proposed in the literature for its ***,the accuracy and computational speed of existing procedures can be improved,which may be critical in situations with rapid irradiance *** this paper,a decoupled photovoltaic power ramp-rate calculation method is presented,in which the effect of variable irradiance and the P&O algorithm are computed *** proposed method has been theoretically demonstrated and tested through simulation and experimental *** results show that it can improve the previous methods in terms of accuracy and computation *** validation with hardware-inthe-loop demonstrates the suitability of the proposed method for real-time applications,even in presence of noisy measurements.

关键词： Hardware-in-the-loop maximum power point tracking perturb and observe photovoltaic power ramp-rate control ramp-rate calculation method

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香椿的树木年轮宽度与超年生殖行为的相互关系:对树轮学研究的警示

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Journal of Plant Ecology 2024年第1期17卷 165-171页

作者： Monique Silva Costa Thaís Jorge de Vasconcellos Claudio sergio Lisi Arno Fritz Neves Brandes Mario Tomazello-Filho Cátia Henriques Callado Instituto de Aplicação Fernando Rodrigues da Silveira Universidade do Estado do Rio de JaneiroRua Barão de Itapagipe96.Rio Comprido 20261-005Rio de JaneiroBrazil Laboratório de Anatomia Vegetal Universidade do Estado do Rio de JaneiroRua São Francisco Xavier524Maracanã20550-013Rio de JaneiroBrazil Departamento de Biologia Universidade Federal de SergipeAv.Marechal Rondon s/n-Rosa Elze.São Cristóvão 49100-000SergipeBrazil Departamento de Biologia Geral Universidade Federal FluminenseRua Prof.Marcos Waldemar de Freitas ReisS/N.Gragoatá24210-201Rio de JaneiroBrazil Escola Superior de Agricultura Luiz de Queiroz Universidade de São PauloAv.Pádua Dias11.Piracicaba 13418-900São PauloBrazil

资源分配到生殖过程涉及到生态和进化因素,可能会减少植物的营养生长。这种相互关系在自然界中不容易观察到,因为有许多参数可以限制生殖结构的产生或生物量的增加。我们将香椿(Cedrela odorata L.,楝科)在里约热内卢州大西洋森林中的... 详细信息

资源分配到生殖过程涉及到生态和进化因素,可能会减少植物的营养生长。这种相互关系在自然界中不容易观察到,因为有许多参数可以限制生殖结构的产生或生物量的增加。我们将香椿(Cedrela odorata L.,楝科)在里约热内卢州大西洋森林中的树木年轮宽度与超年生殖行为相关联。总体而言,生殖结构的发育发生在湿润的年份,在生长季初期没有出现水分亏缺。然而,在这些年份,树木年轮宽度较小。这些结果可能与树木年轮宽度与当地气候之间缺乏相关性有关。因此,我们强调在径向生长研究中纳入生殖数据的重要性,以扩大对热带森林生长变异性的理解。

关键词：植物生长策略树木年轮学树木生态学生殖权衡

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Late Maastrichtian–Paleocene chronostratigraphy from Seymour Island,James Ross Basin,Antarctic Peninsula:Eustatic controls on sedimentation

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Advances in Polar Science 2019年第3期30卷 303-327页

作者： Manuel MONTES Elisabet BEAMUD francisco NOZAL sergio SANTILLANA Instituto Geológico y Minero de Espana(IGME) área de GeologíaGeomorfología y Cartografía GeológicaCalera 128760-Tres CantosMadridSpain Paleomagnetic Laboratory CCiTUB-Instituto de Ciencias de la Tierra'Jaume Almera’-CSIC Sole i Sabariss/n08028-BarcelonaSpain Instituto Antártico Argentino 25 de Mayo 1143San Martínprovincia de Buenos AiresArgentina

The Paleocene(66–56 Ma)was a critical time interval for understanding the geological history in high palaeolatitudes after the end of Cretaceous event(recovery from mass extinction,palaeoclimate,global sea level changes,among others).The sedimentary succession from Seymour Island(Antarctic Peninsula)provides key reference material from this important phase of the early Cenozoic.A detailed age model is proposed for the López de Bertodano Formation(LBF),Sobral Formation(SF)and Cross Valley–Wiman Formation(CVWF)based on a new magnetostratigraphic section which integrates previous dinoflagellate cyst biostratigraphy,Iridium anomaly(K-Pg boundary),U-Pb zircon dating(airfall tuff)and strontium isotope values from *** new composite magnetostratigraphic section,which includes the Cretaceous–Paleogene boundary,has been correlated to the GPTS from C29r up to *** top of the LBF is confirmed as latest Maastrichtian to earliest Danian(~65.4 Ma)in *** overlying SF is mostly Danian in age(~65.2–~63 Ma)and CVWF is Selandian–Thatenian(~61.3–56.9 Ma).LBF,SF and CVWF are unconformity-bounded units(alloformations)that record the geological evolution of the James Ross Basin during a period of relative decreasing tectonism but coeval with volcanic *** based internal units have been recognized,dividing each formation into allomembers(LBF:Molluscan and Cenozoic;SF:A,B and C;CVWF:Díaz,Ara?ado,Bahía Pingüino).The new age model allows correlation of base-level changes with eustatic sea-level *** bases of the SF and CVWF are correlated with the 65.3 and 61.5 Ma sea level lowstands.

关键词： Paleocene magnetostratigraphy Antarctic Peninsula James Ross Basin Seymour Island

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Nanostructured 3-D Collagen/Nanotube Biocomposites for Future Bone Regeneration Scaffolds

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Nano Research 2009年第6期2卷 462-473页

作者： Edelma E.da Silva Heloisa H.M.Della Colleta Andre S.Ferlauto Roberto L.Moreira Rodrigo R.Resende sergio Oliveira Gregory T.Kitten Rodrigo G.Lacerda Luiz O.ladeira Universidade Federal de Minas Gerais Departamento de FísicaLaboratório de NanomateriaisAv.Antônio Carlos662730123-970Belo HorizonteMGBrazil Universidade Federal de Minas Gerais Departamento de MorfologiaAv.Antônio Carlos662730123-970Belo HorizonteMGBrazil

The fi eld of bionanotechnology has been rapidly growing during the last few years and we can now envision a controllable integration between biological and artificial matter,where new biomimetic structures with a wide range of chemical and physical properties will promote the development of a novel generation of medical *** this work we describe a collagen/carbon nanotube composite which has the potential to be used as a scaffold for tissue *** this biocomposite incorporates the advantageous properties of both collagen and carbon nanotubes,it has most of the characteristics that an ideal biomaterial requires in order to be used as an osteoinductive *** biocomposite is bioresorbable and biodegradable and has the desired mechanical rigidity while maintaining a three-dimensional(3-D)nanostructured *** stability and swelling were achieved under fluid environments by varying the amount of carbon nanotubes(CNTs)incorporated into the *** variations can dictate the degree of interaction between fibroblastic cells and the ***-of-concept was shown by performing an in vitro induced mineralization of hydroxylapatite crystals under physiological ***,the ability to attach biofunctional groups to the CNT walls can open a new road for tissue regeneration since the combination of CNTs with specific growth factors or cellular ligands can create an environment capable of signaling and infl uencing specifi c cell *** observations suggest that collagen/carbon nanotube biocomposites will have important uses in a wide range of biotechnological areas.

关键词： Biomaterials carbon nanotubes collagen tissue engineering biocompatibility

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Effect of Nd3+doping on structure,microstructure,lattice distortion and electronic properties of TiO_2 nanoparticles

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Journal of Rare Earths 2017年第3期35卷 259-270页

作者： Balter Trujillo-Navarrete María del Pilar Haro-Vázquez Rosa María Félix-Navarro francisco Paraguay-Delgado Henry Alvarez-Huerta sergio Pérez-Sicairos Edgar Alonso Reynoso-Soto institute technology of tijuana(itt) blvd.alberto limón padillaP.O.B 1166.Tijuana B.C.Mexico university autonomous of baja california(uabc) roadway university14418P.O.B 22390Tijuana B.C.Mexico investigations center of advanced materials(cimav).miguel de cervantes 120.P.O.B31109ChihuahuaMexico

Doped and undoped TiCh nanoparticles were prepared by Stober method and thermally treated at 600 ℃.The effect of Nd^（3＋） ion on the structure and micro structure of anatase-phase TiCh nanocrystals was studied by Rietveld refinement method using X-ray powder diffraction *** lengths,bond angles,and edges distances were *** phase formation was confirmed by high-resolution transmission electron *** adjustment of Ti-0 bond length induced by the addition of Nd^（3＋） ions,reduced the octahedral distortion and altered the octahedral array in the anatase-phase TiCh *** changes of structure and microstructure were mainly observed for TiCh nanoparticles doped with 0.1 at.%of Nd^（3＋） ions and attributed to the cationic substitution of Ti^（4＋） ions which promoted changes in the density of states and gap band of *** dopant insertion resulted in a better structural stability of the nanocrystals that enhanced their charge transference and photocatalytic efficiency.

关键词： neodymium TiO_2 nanoparticles microstructure lattice distortion photocatalytic activity optical properties Rietveld refinement rare earths

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Innovative circular path harvester for mechanical harvesting of irregular and large-canopy olive trees

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International Journal of Agricultural and Biological Engineering 2018年第3期11卷 86-93页

作者： Rafael R.Sola-Guirado Gregorio L.Blanco-Roldan sergio Castro-Garcia francisco J.Castillo-Ruiz Jesus A.Gil-Ribes Department of Rural Engineering E.T.S.I.Agronomos y MontesUniversity of CordobaCampus de RabanalesCtra.Nacional IV Km 396CordobaSpain

The harvesting process of the olive tree is mainly performed by manual means,because traditional olive orchards(the main planting typology)are formed of irregular,large-canopy trees that are very difficult to harvest *** that reason,the cost of harvesting is very high,and it threatens the future of these plantations whose conversion to other more modern layouts is not always possible due to several *** introduction of a harvester may represent the technological change that is the key factor for improved *** main purpose of this work was to develop a harvester based on canopy shaker technology for work on irregular,large trees in a circular *** design of the harvester was based on a determination of tree geometry,together with tree *** tests were used to determine machine-tree interaction,and to evaluate the removal,catch frame and driven *** proposed innovation allowed the fully mechanical harvest of previously planted trees with a removal efficiency of over 84%,achieving an effective field capacity of 0.21 hm^(2)/*** the results so far have been promising,further improvements are advisable in machine and tree adaptation.

关键词： olive tree olive fruit canopy shaker harvester machinery design

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Development of a Multi-DOF Robotic Controller for Academic Purposes

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Journal of Mechanics Engineering and Automation 2015年第5期5卷 269-277页

作者： francisco Mota Munoz sergio Martinez de la Piedra Ingenierla Robotica Universidad Politecnica de Guanajuato Cortazar 38483 Mexico

This article presents the development of a robotic controller for technical training, academic teaching, and research. The controller was designed to interact from 1 to 6 DOF （degrees of freedom） serial robotic arms, actuated by brushed DC （direct current） servomotors equipped with incremental encoders. Controller architecture is based on four components： a processor, a reconfigurable FPGA （field-programmable gate array）, measurement I/O hardware and software. Functionality of the robotic controller has been proved by means of the interaction with an SCARA （selective compliance assembly robot arm）. The proposed controller presents the potential to teach technical courses （like robotics, control, electronics and programming） and to implement and validate advanced control algorithms.

关键词： Open architecture robot control FPGA control implementation academic robot controller.

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A Decade of Changes in the Transportation of Passengers： What Are the Factors That Affected the Demand？

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Journal of Traffic and Transportation Engineering 2016年第6期4卷 299-311页

作者： francisco Gildemir Ferreira Da Silva sergio Aquino de Souza Curso de Finanvas--FEAAC Universidade Federal do Ceara Vila Uniao CEP: 60410-691 Brazil Curso de P6s-Graduaao em Economia Universidade Federal do Ceara Segundo Andar CEP: 60.020-181 Brazil

Ten years of financial stability in Brazilian economy have gone. In this period, the regional transportation of passengers suffered exogenous impacts： economical crises, airport crises and great proportions＇ accidents, as well as impacts which were intern to the system： institutional changes （liberation of tariff promotions, many companies establishing themselves and also coming to bankruptcy）, creation of regulating institutions in the air transportation as well as the land transportation. Theoretically, it is expected that these changes have generated impacts in the demand for trips, since an environment regulated with more flexible prices and higher amounts of companies would generate a competitive environment in which the companies could struggle to attract their demand. On the other hand, the impacts which are exogenous to the system can generate responses in the sense of restoring the balance of demand. Thus, based on the theoretical experience, this article aims at analyzing empirically, through categorical variables, if there were impacts on the demand for regional trips in Brazil due to the internal or external changes. In order to perform this, monthly data from January, 1999 to December, 2009 are utilized and estimates are calculated making use of SUR （seemingly unrelated regressions）. As a result, we have the meaning of the internal and external impacts related to air and land transports, identifying that the worldwide economic crisis generated an impact at the level of the demand for transportation and also that the flexibility of tariffs allowed by ANTT （Ag^ncia Nacional de Transportes Terrestres） had an equal impact on the demand for land transportation.

关键词： Seemingly unrelated regressions passengers transport demand analysis.

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