检索结果-南通市图书馆

A coupled fluid FEM-DEM technique for predicting blasting operations in tunnels

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Underground Space 2018年第4期3卷 310-316页

作者： Francisco Zarate Jose M.Gonzalez Juan Miquel Rainald Lohner eugenio Onate Centre Internacional de Metodes Numerics en Enginyeria(CIMNE) Spain Universitat Politecnica de Catalunya(UPC) Gran Capitan s/nCampus Nord08034 BarcelonaSpain George Mason University USA1

We present recent developments in the coupling of the finite element method(FEM)and the discrete element method(DEM)for the analysis of rock blasting operations in *** coupled FEM-DEM technique has been proven to be an efficient procedure for pre-dicting the multiple fractures of rock induced by the loads generated in *** coupled FEM-DEM procedure is applied in tunnel construction,as well as to gas pressure blasting pyrotechnics to break rocks for the excavation of the tunnel *** the latter case,the effect of gas explosion is modeled by solving the equations of gas dynamics in the analysis domain using *** effect of gas forces in the underlying rock mass is modeled via an embedded fluid-structure interaction *** efficiency of the coupled FEM-DEM tech-nique is demonstrated in several examples of fracture tests and rock blasting problems related to tunnel *** examples pre-sented indicate that the combination of the DEM with simple three-node linear triangular elements(for two-dimensional problems)captures the onset of fractures and their evolution accurately,accounting for the penetration of gas in the failure domain(Zarate&Onate,2015;Zarate,Cornejo,&Onate,2018).

关键词： Discrete elements Finite elements Fracture mechanics FEM-DEM Gas dynamics

Soil organic carbon stocks in native forest of Argentina:a useful surrogate for mitigation and conservation planning under climate variability

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ecological Processes 2024年第1期13卷 3-24页

作者： Pablo L.Peri Juan Gaitán Matías Mastrangelo Marcelo Nosetto Pablo E.Villagra Ezequiel Balducci Martín Pinazo Roxana P.Eclesia Alejandra Von Wallis Sebastián Villarino Francisco Alaggia Marina González Polo Silvina Manrique Pablo A.Meglioli Julián Rodríguez-Souilla Martín Mónaco Jimena E.Chaves Ariel Medina Ignacio Gasparri eugenio Alvarez Arnesi María Paula Barral Axel von Müller Norberto M.Pahr Josefina Uribe Echevarria Pedro Fernández Marina Morsucci Dardo López Juan Manuel Cellini Leandro Alvarez Ignacio Barberis Hernán Colomb Ludmila La Manna Sebastián Barbaro Cecilia Blundo Ximena Sirimarco Laura Cavallero Gualberto Zalazar Guillermo Martínez Pastur Instituto Nacional de Tecnología Agropecuaria (INTA) Universidad Nacional de la Patagonia Austral (UNPA) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Universidad Nacional de Luján Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Grupo de Estudio de Agroecosistemas y Paisajes Rurales (GEAP) Universidad Nacional de Mar del Plata Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET ) CCT San Luis Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Instituto Argentino de Nivología Glaciología y Ciencias Ambientales (IANIGLA) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Universidad Nacional de Cuyo Instituto de Investigaciones en Biodiversidad y Medioambiente (INIBIOMA) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Instituto de Investigaciones en Energía No Convencional CCT Salta-JujuyConsejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Laboratorio de Recursos Agroforestales Centro Austral de Investigaciones Científicas (CADIC) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Dirección Nacional de Bosques Ministerio de Ambiente y Desarrollo Sostenible de la Nación Instituto de Ecología Regional Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET )Universidad Nacional de Tucumán Universidad Nacional de Rosario Instituto de Investigaciones en Ciencias Agrarias de Rosario Centro Científico Tecnológico CONICET Grupo de Estudio de Agroecosistemas y Paisajes Rurales (GEAP) Universidad Nacional de Mar del Plata Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Laboratorio de Investigaciones en Maderas (LIMAD) Universidad Nacional de La Plata (UNLP) Administración de Parques Nacionales (APN) Parque Nacional Los Alerces Centro de Estudios Ambientales Integrados (CEAI) Universidad Nacional de la Patagonia San Juan Bosco (UNPASJB) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET )

Background The nationally determined contribution（NDC） presented by Argentina within the framework of the Paris Agreement is aligned with the decisions made in the context of the United Nations Framework Conven-tion on Climate Change（UNFCCC） on the reduction of emissions derived from deforestation and forest degradation, as well as forest carbon conservation（REDD+）. In addition, climate change constitutes one of the greatest threats to forest biodiversity and ecosystem services. However, the soil organic carbon（SOC） stocks of native forests have not been incorporated into the Forest Reference Emission Levels calculations and for conservation planning under cli-mate variability due to a lack of information. The objectives of this study were:（i） to model SOC stocks to 30 cm of native forests at a national scale using climatic, topographic and vegetation as predictor variables, and（ii） to relate SOC stocks with spatial–temporal remotely sensed indices to determine biodiversity conservation concerns due to threats from high inter-annual climate *** We used 1040 forest soil samples（0–30 cm） to generate spatially explicit estimates of SOC native forests in Argentina at a spatial resolution of approximately 200 m. We selected 52 potential predictive environmental covari-ates, which represent key factors for the spatial distribution of SOC. All covariate maps were uploaded to the Google Earth Engine cloud-based computing platform for subsequent modelling. To determine the biodiversity threats from high inter-annual climate variability, we employed the spatial–temporal satellite-derived indices based on Enhanced Vegetation Index（EVI） and land surface temperature（LST） images from Landsat *** SOC model（0–30 cm depth） prediction accounted for 69% of the variation of this soil property across the whole native forest coverage in Argentina. Total mean SOC stock reached 2.81 Pg C（2.71–2.84 Pg C with a probability of 90%） for a total area of 460,790 km2,

关键词： Soil organic carbon Biodiversity Native forest Climate change mitigation Modelling Resilience

How the optical timing system,the longitudinal diagnostics and the associated feedback systems provide femtosecond stable operation at the FERMI free electron laser

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

High Power Laser Science and Engineering 2016年第2期4卷 14-28页

作者： Mario Ferianis Enrico Allaria eugenio Ferrari Giulio Gaio Giuseppe Penco Fabio Rossi Marco Veronese Elettra-Sincrotrone Trieste S.C.p.A.

FERMI, the seeded free electron laser(FEL) in operation in Italy, is providing the User Community with unique fully coherent radiation, in the wavelength range 100–4 nm. FERMI is the first FEL fully synchronized by means of optical fibers. The optical timing system ensures an ultra-stable phase reference to its distributed clients. Several femtosecond longitudinal diagnostics verify the achieved performance; the bunch length monitor(BLM) and the bunch arrival monitor(BAM) will be presented in this paper. Feedback systems play a crucial role to guarantee the needed longterm electron beam stability. A real-time infrastructure allows shot-to-shot communication between front-end computers and the servers. Orbit feedbacks are useful in machine tuning, whereas longitudinal feedbacks control electron energy,compression and arrival time. A flexible software framework allows a rapid implementation of heterogeneous multiinput–multi-output(MIMO) longitudinal loops simply by selecting the appropriate sensors and actuators.

关键词： feedback system femtosecond longitudinal diagnostics optical timing

维普期刊数据库

Tectonically asymmetric Earth:From net rotation to polarized westward drift of the lithosphere

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2015年第3期6卷 401-418页

作者： Carlo Doglioni eugenio Carminati Mattia Crespi Marco Cuffaro Mattia Penati Federica Riguzzi Dipartimento di Scienze della Terra Sapienza Universita di Roma DITS-Area di Geodesia e Geomatica Sapienza Universita di Roma Istituto di Geologia Ambientale e Geoingegneria CNR MOX-Dipartimento di Matematica Politecnico di Milano Istituto Nazionale di Geofisica e Vulcanologia Sez.CNTRomeItaly

The possibility of a net rotation of the lithosphere with respect to the mantle is generally overlooked since it depends on the adopted mantle reference frames, which are arbitrary. We review the geological and geophysical signatures of plate boundaries, and show that they are markedly asymmetric worldwide. Then we compare available reference frames of plate motions relative to the mantle and discuss which is at best able to fit global tectonic data. Different assumptions about the depths of hotspot sources （below or within the asthenosphere, which decouples the lithosphere from the deep mantle） predict different rates of net rotation of the lithosphere relative to the mantle. The widely used no-net-rotation （NNR） reference frame, and low （〈0.2°-0.4°/Ma） net rotation rates （deep hotspots source） predict an average net rotation in which some plates move eastward relative to the mantle （e.g., Nazca）. With fast （〉1°/Ma） net rotation （shallow hotspots source）, all plates, albeit at different velocity, move westerly along a curved trajectory, with a tectonic equator tilted about 30° relative to the geographic equator. This is consistent with the observed global tectonic asymmetries.

关键词： Asymmetric plate tectonics Plate motions Westward drift Mantle convection

维普期刊数据库

Sustainable water resource management in steep-slope agriculture

在线全文

学校读者我要写书评

暂无评论

Geography and Sustainability 2022年第3期3卷 214-219页

作者： Wendi Wang eugenio Straffelini Anton Pijl Paolo Tarolli Department of Land EnvironmentAgriculture and ForestryUniversity of PadovaAgripolisViale dell’Università16Legnaro 35020PDItaly

Steep-slope agricultural landscapes are under threat due to climate *** the one hand,the growing fre-quency of extreme high-intensity rainfall events concentrated in both temporal and spatial scales are causing flash floods or slope failure risk *** the other hand,future climate projections indicate a significant expansion of arid zones in the steep slope agricultural *** is evidence that these landscapes face a high risk of growing water *** their unique role in crop production,ecosystem diversity,and crop production,ecosystem diversity,and cultural heritage,understanding sustainable water resource manage-ment for mitigating climate change-induced drought has never been more urgent than *** these landscapes,unique indigenous knowledge of water conservation is adopted to manage water resources improving their re-silience *** is,therefore,necessary to promote water storage to mitigate floods or increase the resilience to prolonged drought(creating at the same time favourable conditions for biodiversity).Modern technological advances(e.g.,high-resolution remote sensing and GIS-based modelling)are crucial in supporting these activities and understanding earth’s surface processes.

关键词： Steep slope agriculture Water Climate change SDG

Probability distributions of arsenic in soil from brownfield sites in Beijing （China）： statistical characterization of the background populations and implications for site assessment studies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2015年第3期9卷 465-474页

作者： Marina ACCORNERO Lin JIANG eugenio NAPOLI Marco CREMONINI Giovanni FERRO Federica BELLORO Maosheng ZHONG D'Appolonia S.p.A. Genoa 16145 Italy Beijing Municipal Institute of Environmental Protection Beijing 100037 China Ingegneria e Servizi Ambientali Ferro S.r.l. Savorta 17100 Italy

A probabilistic analysis was performed on soil arsenic concentration data from 4 brownfield sites at Beijing （Chaoyang and Haidian Districts）, involved in environmental assessment studies. The available data sets were processed to provide a statistical characterization of the background populations and differentiate ＂anomalous data＂ from the natural range of variation of arsenic concentrations in soil. The site-specific background distributions and the existing wide-scale background values defined for the Beijing area were compared, discussing related implications for the definition of metal contamination soil screening levels （SSLs） in site assess- ment studies. The statistical analysis of As data sets discriminated site-specific background populations, encompassing 88% to 94% of the sample data, from oufliers values, associated with either subsoil natural enrichments or possible anthropogenic releases. Upper Baseline Concentration （UBC） limits （＋ 2σ level）, including most of the site-specific metal background variability, were derived based on the statistical characterization of the background populations. Sites in the Chaoyang South District area had UBC values in the range 10.4-12.6mg·kg^-1. These ranges provide meaningful SSL values to be adopted for As in local site assessment studies. Using the wide-scale background value for the Beijing area would have erroneously classified most of the areas in the subject sites as potentially contaminated.

关键词： arsenic probability plot upper baseline con-centration site assessment

维普期刊数据库

A flexible ECG patch compatible with NFC RF communication

在线全文

学校读者我要写书评

暂无评论

npj Flexible Electronics 2020年第1期4卷 126-133页

作者： Mohammad Zulqarnain Stefano Stanzione Steve Smout Myriam Willegems Kris Myny eugenio Cantatore Integrated Circuits Group Eindhoven University of TechnologyEindhovenThe Netherlands Holst Centre/imec EindhovenThe Netherlands imec LeuvenBelgium

With the advent of the internet of things,flexible wearable devices are gaining significant research interest,as they are unobtrusive,comfortable to wear and can support continuous observation of physiological signals,helping to monitor wellness or diagnose *** Indium Gallium Zinc Oxide(a-IGZO)Thin Film Transistors(TFTs)fabricated on flexible substrates are an attractive option to build such bio-signal monitoring systems due to their flexibility,conformability to the human body,and low *** paper presents a flexible electrocardiogram(ECG)patch implemented on foil with self-aligned IGZO TFTs,which is capable to acquire the ECG signals,amplify them and convert them to a sequence of *** analogue frontend has a measured input-referred noise of 8μV_(rms) in the 1-100 Hz *** system achieves experimentally 67.4 dB CMRR,58.9 dB PSRR,and 16.5 MΩinput impedance at 50 Hz while using 1 kHz *** signal from the electrodes is transformed to a 105.9-kb/s Manchester-encoded serial bit stream which could be sent wirelessly to a smart phone via Near Field Communication(NFC)for further *** consumption is 15.4 mW for the digital and 280μW for the analogue *** contribution shows the fundamental steps to demonstrate intelligent plasters for biomedical applications based on flexible electronics providing an NFC-compatible digital output bit stream.

关键词： NFC communication patch

Differential diagnosis in inflammatory bowel disease colitis:State of the art and future perspectives

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2015年第1期21卷 21-46页

作者： Gian eugenio Tontini Maurizio Vecchi Luca Pastorelli Markus F Neurath Helmut Neumann Gastroenterology and Digestive Endoscopy Unit IRCCS Policlinico San Donato20097 San Donato MilaneseItaly Department of Medicine I University of Erlangen-Nuremberg91054 ErlangenGermany Department of Biomedical Sciences for Health University of Milan20122 MilanoItaly

Distinction between Crohn's disease of the colonrectum and ulcerative colitis or inflammatory bowel disease(IBD) type unclassified can be of pivotal importance for a tailored clinical management,as each entity often involves specific therapeutic strategies and ***,no gold standard is available and the uncertainty of diagnosis may frequently lead to misclassification or repeated ***,we have performed a literature search to address the problem of differential diagnosis in IBD colitis,revised current and emerging diagnostic tools and refined disease classification ***,the differential diagnosis is an untangled issue,and the proper diagnosis cannot be reached in up to 10% of patients presenting with IBD *** topic is receiving emerging attention,as medical therapies,surgical approaches and leading prognostic outcomes require more and more disease-specific strategies in IBD *** optimization of standard diagnostic approaches based on clinical features,biomarkers,radiology,endoscopy and histopathology appears to provide only marginal ***,emerging diagnostic techniques in the field of gastrointestinal endoscopy,molecular pathology,genetics,epigenetics,metabolomics and proteomics have already shown promising *** advanced endoscopic imaging techniques and biomarkers can shed new light for the differential diagnosis of IBD,better reflecting diverse disease behaviors based on specific pathogenic pathways.

关键词： Crohn’s disease Ulcerative colitis Inflammatory bo

Multiple cells of origin in cholangiocarcinoma underlie biological,epidemiological and clinical heterogeneity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2012年第5期4卷 94-102页

作者： Vincenzo Cardinale Guido Carpino Lola Reid eugenio Gaudio Domenico Alvaro Department of MedicoSurgical Sciences and Biotechnologies Polo PontinoSapienza University of Rome00137 RomeItaly Department of Health Sciences University of Rome "Foro Italico"000135 RomeItaly Department of Anatomical HistologicalForensic Medicine and Orthopedics SciencesSapienza University of Rome000137 RomeItaly Department of Cell and Molecular Physiology Biomedical EngineeringProgram in Molecular Biology and BiotechnologyUNC School of MedicineChapel HillNC 27599United States Eleonora Lorillard Spencer-Cenci Foundation 00156 RomeItaly

Recent histological and molecular characterization of cholangiocarcinoma(CCA) highlights the heterogeneity of this cancer that may emerge at different sites of the biliary tree and with different macroscopic or morphological ***,different stem cell niches have been recently described in the liver and biliarytree,suggesting this as the basis of the heterogeneity of intrahepatic(IH)-and extrahepatic(EH)-CCAs,which are two largely different tumors from both biological and epidemiological points of *** complexity of the organization of the liver stem cell compartments could underlie the CCA clinical-pathological heterogeneity and the criticisms in classifying primitive liver *** recent advances highlight a possible new classification of CCAs based on cells of origin and this responds to the need of generating homogenous diagnostic,prognostic and,hopefully,therapeutic categories of IH-and EH-CCAs.

关键词： Intrahepatic cholangiocarcinoma Extrahepatic cholangiocarcinoma Cholangiocarcinoma classification Cholangiolocarcinoma Cells of origin Cancer stem cells Peribiliary glands Biliary tree stem/progenitor cells Human hepatic stem cells Risk factors Targeted therapies