检索结果-南通市图书馆

Nano Research 2016年第10期9卷 3018-3026页

作者： Giovanna Trevisi luca Seravalli Paola Frigeri CNR-IMEM Institute Parco Area delle Scienze 37a 43124 Parma Italy

The room-temperature light emission of uncapped III-V semiconductor quantum dots is used to investigate the properties and evolution of the surface under exposure to a humid environment. Enhanced photoluminescence intensity resulting from exposure to polar molecules has already been reported; here we demonstrate that the external environment also has a relevant effect on the emission energy of quantum dots. Experimental results are interpreted on the basis of a model of the quantum system that takes into account the formation of oxide on pristine III-V surfaces and the presence of surface states. As a result of our study, we can clearly distinguish the effect of surface oxidation from that of surface state passivation on the emission of InAs surface quantum dots. This work sheds new light on the properties of semiconductor surface quantum dots as building blocks of novel and highly efficient sensing devices based on optical transduction.

关键词： epitaxial quantum dots surface states oxide photoluminescence quantum modeling optical nanosensor

SRAM-Based FPGA Systems for Safety-Critical Applications： A Survey on Design Standards and Proposed Methodologies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2015年第2期30卷 373-390页

作者： Cinzia Bernardeschi luca Cassano Andrea Domenici Department of Information Engineering University of Pisa Pisa 56122 Italy Dipartimento di Elettronica Informazione e Bioingegneria Politecnico di Milano Milano 20133 Italy

As the ASIC design cost becomes affordable only for very large-scale productions, the FPGA technology is currently becoming the leading technology for those applications that require a small-scale production. FPGAs can be considered as a technology crossing between hardware and software. Only a small-number of standards for the design of safety-critical systems give guidelines and recommendations that take the peculiarities of the FPGA technology into consideration. The main contribution of this paper is an overview of the existing design standards that regulate the design and verification of FPCA-based systems in safety-critical application fields. Moreover, the paper proposes a survey of significant published research proposals and existing industrial guidelines about the topic, and collects and reports about some lessons learned from industrial and research projects involving the use of FPGA devices.

关键词： design verification electronic design safety-critical system SRAM-based FPGA

Diagnostic accuracy and cost-effectiveness of the CAR-OLT score in predicting cardiac risk for liver transplantation

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 Transplantation 2025年第2期15卷 138-148页

作者： Marco Biolato luca Miele Alfonso W Avolio Giuseppe Marrone Antonio Liguori Francesco Galati Anna Petti Lidia Tomasello Daniela Pedicino Antonella Lombardo Alessia D'Aiello Maurizio Pompili Salvatore Agnes Antonio Gasbarrini Antonio Grieco Department of Medical and Surgical Sciences Centro Malattie Apparato Digerente(CEMAD)Fondazione Policlinico Universitario Agostino GemelliIstituto di Ricerca e Cura a Carattere Scientifico(IRCCS)Rome 00168LazioItaly Department of Translational Medicine and Surgery Catholic University of Sacred HeartRome 00168LazioItaly General Surgery and Liver Transplantation Unit Fondazione Policlinico Universitario Agostino GemelliIstituto di Ricerca e Cura a Carattere Scientifico(IRCCS)Rome 00168LazioItaly Department of Cardiovascular Sciences Fondazione Policlinico Universitario Agostino GemelliIstituto di Ricerca e Cura a Carattere Scientifico(IRCCS)Rome 00168LazioItaly

BACKGROUND The CAR-OLT score predicts major adverse cardiovascular events 1 year after liver transplant(LT).AIM To test the hypothesis that the CAR-OLT score may help avoid cardiac stress tests in LT *** This retrospective single-center cohort study included all adult patients undergoing elective evaluation for first cadaveric donor orthotopic LT for liver cirrhosis with or without hepatocellular carcinoma at Fondazione Policlinico Universitario Agostino Gemelli Istituto di Ricerca e Cura a Carattere Scientifico in Rome,*** contraindications for LT listing were defined after a center-specific cardiac workup,which included cardiac stress tests for most *** diagnostic accuracy of the CAR-OLT score was evaluated using the area under the receiver operating characteristic(AUROC)*** A total of 342 LT candidates were evaluated between 2015 and 2019,with a moderate cardiovascular risk profile(37%diabetes,34%hypertension,22%obesity).Of these,80(23%)candidates underwent coronary ***-one(6%)candidates were given cardiac contraindications to LT listing,48%of which were due to coronary artery *** CAR-OLT score predicted cardiac contraindications to LT listing with an AUROC of *** optimal cut-off for sensitivity was a CAR-OLT score≤23,which showed a 99%negative predictive value for cardiac contraindications to LT listing.A total of 84(25%)LT candidates with a CAR-OLT score≤23 underwent 87 non-invasive cardiac tests and 13 coronary angiographies pre-listing,with estimated costs of approximately 48000€.The estimated savings per patient was€574.70 for the Italian National Health *** A CAR-OLT score≤23 can identify LT candidates who can be safely listed without the need for cardiac stress tests,providing time and cost *** findings require external validation.

关键词： Transplantation Coronary artery disease Pharmacoeconomic Listing Major adverse cardiovascular events

Blood group type antigens in pancreatic intraductal papillary mucinous neoplasms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2014年第1期13卷 74-80页

作者： Adriana Handra-luca Departments of Pathology Sydney Kimmel Comprehensive Cancer Center Johns Hopkins Medical Institutions APHP Universite Paris Nord Sorbonne Cite-Sce Anatomie Pathologique GHU Avicenne 125 rue Stalingrad Bobigny 93000 France

BACKGROUND: There are few data on blood group(BG) types and types of pancreatic cancers. The aims of this study were to study BG types and BG-antigens in pancreatic intraductal papillary mucinous neoplasms(IPMNs). METHODS: BG type and tumor BG-antigen(glycoprotein) expression(studied by immunohistochemistry on tissue microarrays) were analyzed with regard to characteristics of 101 surgically resected pancreatic IPMNs. RESULTS: Non-O BG type predicted invasive carcinoma independently from high serum CA19-9 and male gender. BG type A was observed more frequently in women than in men. Chronic pancreatitis was more frequently seen in patients with BG type B or AB. Aberrant tumor expression(with regard to BG type) of loss of A antigen expression type occurred in 15.0% of IPMNs and of loss of B antigen expression type in 62.5% of IPMNs. Intraneoplasm BG-antigen expression was not related to dysplasia grade or invasion. CONCLUSION: The results of the study suggest that in pancreatic IPMN, non-O BG type predicted invasive carcinoma, whereas for intratumor BG-antigen expression no specific patterns were detected with regard to the progression of glandular epithelial dysplasia or invasion.

关键词： blood group type blood group antigen immunohistochemistry CA19-9 prognosis invasive carcinoma pancreas intraductal papillary mucinous neoplasm

Searching for alternatives to brain regeneration

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2021年第11期16卷 2198-2200页

作者： Chiara La Rosa luca Bonfanti Neuroscience Institute Cavalieri Ottolenghi(NICO) OrbassanoItaly Department of Veterinary Sciences University of TurinGrugliascoItaly

Brain regeneration from an evolutionary perspective:Brain regeneration(the full restoration of tissue after loss from injury or disease)is the most sought after goal for researchers working in developmental *** also appears to be the most challenging to achieve when considering the mammalian *** remarkable regenerative capacities can be present in the central nervous systems of many non-mammalian vertebrates(e.g.,fish,amphibians),these kinds of processes appear to be dramatically reduced in mammals(Bonfanti,2011).

关键词： regeneration sought injury

Interpreting siliciclastic sedimentation in the upper Paleozoic Mulargia-Escalaplano Basin(Sardinia, Italy):influence of tectonics on provenance

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2024年第1期13卷 18-34页

作者： luca G.Costamagna Sara Criniti Dipartimento di Scienze Chimiche e Geologiche Citadella UniversitariaBlocco A09042 Monserrato CAItaly Dipartimento di Ingegneria dell'Ambiente Universita della Calabria87036 Arcavacata di Rende CSItaly

Late to post-Variscan molassic basins of Late Pennsylvanian-Permian age are exposed in Sardinia(Italy). Here, the compositional and stratigraphic evolution of the Mulargia-Escalaplano sedimentary basin(central Sardinia) has been investigated to highlight how the tectono-magmatic processes have influenced the sedimentation. Ruditic and arenitic samples were collected along well-characterized stratigraphic sections to provide a new insight into the impact of the tectono-magmatic processes on siliciclastic sedimentation. As a result, the conglomerates are mainly clast-supported, petromictic, and thus immature, with no defined maturity trend upwards. Nevertheless, pebble composition changes in times from Variscan basement pebble-rich to volcanic rock-rich, as a consequence of the basin widening and the dismantling and reworking of the coeval volcanic activity. The sandstone composition clearly changes from quartzolithic to feldspatholithic upwards, as a response to the same change of feeding and reworking of the volcanic rocks. Occasionally, interbedded quartzolithic arenites suggest exceptional floods carrying debris from the far borders of the basin. Also, the immature sandstone composition has been interpreted as being controlled by a continuous supply of fresh debris and to a rapid burial rate. In addition, the disappearance of metaradiolarite(lydite AA) Paleozoic grains in the sandstone mineral suite could represent a distinctive marker of a progressive unroofing of the Variscan chain and a clastic supply from deeper tectonic units.

关键词： Petrography Stratigraphy Provenance Molassic basins Sardinia

Multi-temporal modeling of road-induced overland flow alterations in a terraced landscape characterized by shallow landslides

在线全文

学校读者我要写书评

暂无评论

International Soil and Water Conservation Research 2022年第2期10卷 240-253页

作者： luca Mauri Eugenio Straffelini Paolo Tarolli Department of Land EnvironmentAgriculture and ForestryUniversity of PadovaAgripolisViale Dell’Università 1635020Legnaro(PD)Italy

The presence of roads in high steep agricultural systems is often linked with landslides *** research aims to model multi-temporal overland flow dynamics in a shallow landslides-prone terraced landscape(northern Italy).The combined use of Remotely Piloted Aircraft Systems(RPAS)and photo-grammetric techniques(e.g.,Structure from Motion-SfM)allowed to elaborate multi-temporal high-resolution Digital Elevation Models(DEMs).Hydrological analyses of water flow's depth alterations due to the road presence were carried out adopting the SIMulated Water Erosion model(SIMWE),focusing on different scenarios considering the presence of the road and assuming its absence through a specific DEM smoothing *** possibility to perform multi-temporal hydrological simulations at a hillslope scale so as to analyse the role played by the road in overland flows alteration is still a challenge to be *** proved the role played by the road in water flows change above the two observed shallow landslides,with respective maximum water depth values equal to 0.18 m and 0.14 *** the contrary,no-road simulations not revealed significant water flows deviations towards landslides,with water depth values around 0 m,underlining that the absence of the road would avoid relevant changes in water flow paths toward the collapsed *** work could be a solid starting point for analyse road impact on runoff dynamics and hillslopes stability also at a wider scale,as well as for planning efficient mitigation intervention so as to reduce the occurrence of similar future scenarios.

关键词： Terraced landscape Road Landslide Remote sensing DEM

Intra-cycle depolarization of ultraintense laser pulses focused by off-axis parabolic mirrors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Power Laser Science and Engineering 2018年第2期6卷 141-148页

作者： luca Labate Gianluca Vantaggiato Leonida A.Gizzi Istituto Nazionale di Ottica Consiglio Nazionale delle Ricerche Istituto Nazionale di Fisica Nucleare Sezione di Pisa

A study of the structure of the electric and magnetic fields of ultraintense laser pulses focused by an off-axis parabolic mirror is reported. At first, a theoretical model is laid out, whose final equations integration allows the space and time structure of the fields to be retrieved. The model is then employed to investigate the field patterns at different times within the optical cycle, for off-axis parabola parameters normally employed in the context of ultraintense laser–plasma interaction experiments. The results show that nontrivial, complex electromagnetic field patterns are observed at the time at which the electric and magnetic fields are supposed to vanish. The importance of this effect is then studied for different laser polarizations, f numbers and off-axis angles.

关键词： laser-driven particle acceleration laser focusing off-axis parabolic mirrors ultrashort laser pulses

Zeckendorf representations with at most two terms to x-coordinates of Pell equations

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2020年第4期63卷 627-642页

作者： Carlos A.Gómez Florian luca Departamento de Matematicas Universidad del ValleCali 25360Colombia School of Mathematics University of the WitwatersrandWits 2050South Africa Max Planck Institute for Mathematics Bonn 53111Germany Department of Mathematics Faculty of SciencesUniversity of OstravaOstrava 70103Czech Republic

In this paper,we find all positive squarefree integers d satisfying that the Pell equation X^2-d Y^2=±1 has at least two positive integer solutions(X,Y)and(X′,Y′)such that both X and X′have Zeckendorf representati... 详细信息

关键词： Pell equation Fibonacci numbers lower bounds for linear forms in logarithms reduction method

Well-Posedness of Stochastic Continuity Equations on Riemannian Manifolds

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2024年第1期45卷 81-122页

作者： luca GALIMBERTI Kenneth H.KARLSEN Department of Mathematical Sciences NTNU Norwegian University of Science and TechnologyN-7491 TrondheimNorway Department of mathematics University of OsloP.O.Box 1053BlindernN-0316 OsloNorway

The authors analyze continuity equations with Stratonovich stochasticity,■ρ+divh[ρo(u(t,x)+∑_(i=1)^(N)a_(i)(x)w_(i)(t))]=0defined on a smooth closed Riemannian manifold M with metric *** velocity field u is perturbed by Gaussian noise terms Wi(t),:WN(t)driven by smooth spatially dependent vector fields a1(x),...,aN(x)on *** velocity u belongs to L_(t)^(1)W_(x)^(1,2)with divh u bounded in Lf,for p>d+2,where d is the dimension of M(they do not assume div_(h) u∈L_(t,x)^(∞)).For carefully chosen noise vector fields ai(and the number N of them),they show that the initial-value problem is well-posed in the class of weak L^(2) solutions,although the problem can be ill-posed in the deterministic case because of concentration *** proof of this“regularization by noise”result is based on a L^(2) estimate,which is obtained by a duality method,and a weak compactness argument.

关键词： Stochastic continuity equation Riemannian manifold Hyperbolic equa-tion Non-smooth velocity field Weak solution Existence Uniqueness