检索结果-南通市图书馆

Synergistic effect between few layer graphene and carbon nanotube supports for palladium catalyzing electrochemical oxidation of alcohols

引用

Journal of Energy Chemistry 2013年第2期22卷 296-304页

作者： Bruno F. Machado andrea marchionni Revathi R. Bacsa Marco Bellini Julien Beausoleil Werner Oberhauser Francesco Vizza Philippe Serp Laboratoire de Chimie de Coordination UPR CNRS 8241 Composante ENSIACET Universit de Toulouse UPS-INP-LCC 4 alle Emile Monso BP 44362 31432 Toulouse Cedex 4 France Istituto di Chimica dei Composti Organometallici (ICCOM-CNR) Via Madonna del Piano 10 50019 Sesto Fiorentino Italy Arkema Groupement de Recherches de Lacq BP 34 RD 817 64170 Lacq France

Few layer graphene （FLG）, multi-walled carbon nanotubes （CNTs） and a nanotube-graphene composite （CNT-FLG） were used as supports for palladium nanoparticles. The catalysts, which were characterized by transmission electron microscopy, Raman spectroscopy and X-ray diffraction, were used as anodes in the electrooxidation of ethanol, ethylene glycol and glycerol in half cells and in passive direct ethanol fuel cells. Upon Pd deposition, a stronger interaction was found to occur between the metal and the nanotube-graphene composite and the particle size was significantly smaller in this material （6.3 nm）, comparing with nanotubes and graphene alone （8 and 8.4 nm, respectively）. Cyclic voltammetry experiments conducted with Pd/CNT, Pd/FLG and Pd/CNT-FLG in 10 wt% ethanol and 2 M KOH solution, showed high specific currents of 1.48, 2.29 and 2.51 mA-/zgp-d, respectively. Moreover, the results obtained for ethylene glycol and glycerol oxidation highlighted the excellent electrocatalytic activity of Pd/CNT-FLG in terms of peak current density （up to 3.70 mAgd for ethylene glycol and 1.84 mAfor glycerol, respectively）. Accordingly, Pd/CNT-FLG can be considered as the best performing one among the electrocatalysts ever reported for ethylene glycol oxidation, especially considering the low metal loading used in this work. Direct ethanol fuel cells at room temperature were studied by obtaining power density curves and undertaking galvanostatic experiments. The power density outputs using Pd/CNT, Pd/FLG and Pd/CNT-FLG were 12.1, 16.3 and 18.4 ***-2, respectively. A remarkable activity for ethanol electrooxidation was shown by Pd/CNT-FLG anode catalyst. In a constant current experiment, the direct ethanol fuel cell containing Pd/CNT-FLG could continuously deliver 20 ***-2 for 9.5 h during the conversion of ethanol into acetate of 30%, and the energy released from the cell was about 574 J.

关键词： electrooxidation alcohols fuel cells palladium graphene nanotube-graphene composites

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

Spatio-temporal coupled mode theory for nonlocal metasurfaces

引用

Light(Science & Applications) 2024年第2期13卷 267-282页

作者： Adam Overvig Sander A.Mann andrea Alù Photonics Initiative Advanced Science Research CenterCity University of New YorkNew YorkNY10031USA Physics Program Graduate Center of the City University of New YorkNew YorkNY10016USA

Diffractive nonlocal metasurfaces have recently opened a broad range of exciting developments in nanophotonics research and applications,leveraging spatially extended—yet locally patterned—resonant modes to control light with new degrees of *** conventional grating responses are elegantly captured by temporal coupled mode theory,current approaches are not well equipped to capture the arbitrary spatial response observed in the nascent field of nonlocal ***,we introduce spatio-temporal coupled mode theory(STCMT),capable of elegantly capturing the key features of the resonant response of wavefront-shaping nonlocal *** framework can quantitatively guide nonlocal metasurface design while maintaining compatibility with local metasurface frameworks,making it a powerful tool to rationally design and optimize a broad class of ultrathin optical *** validate this STCMT framework against full-wave simulations of various nonlocal metasurfaces,demonstrating that this tool offers a powerful semi-analytical framework to understand and model the physics and functionality of these devices,without the need for computationally intense full-wave *** also discuss how this model may shed physical insights into nonlocal phenomena in photonics and the functionality of the resulting *** a relevant example,we showcase STCMT’s flexibility by applying it to study and rapidly prototype nonlocal metasurfaces that spatially shape thermal emission.

关键词： theory resonant spatially

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

Proximity to corridors benefits bird communities in vegetated interrow vineyards in Mendoza, Argentina

引用

Avian Research 2024年第2期15卷 147-155页

作者： andrea Paula Goijman Agustín Zarco EEA La Consulta Instituto Nacional de Tecnología Agropecuaria(INTA)San CarlosMendozaArgentina Instituto Argentino de Investigacion en las Zonas Aridas(IADIZA)CONICET 5500MendozaArgentina

Management under ecological schemes and increasing habitat heterogeneity,are essential for enhancing biodiversity in *** provide several contributions to agriculture,for example pest control,recreation and enhancing human mental health,and have intrinsic *** are also ideal model organisms because they are easy to survey,and species respond differently to agricultural land use at different *** borders of crops are key for many species of birds,and distance to the border have been found to be an important factor in vineyard-dominated *** evaluate if there are differences in the bird assemblage,between the interior compared to borders within vineyards,using a hierarchical community occupancy *** hypoth-esized that occupancy of birds is greater in environments with greater heterogeneity,which in this study was considered to be contributed by the proximity to vegetated *** expected that vineyard borders close to corridors will have higher bird occupancy than the center of the *** research was conducted in three vineyards with biodiversity-friendly management practices,in Gualtallary,Mendoza,*** surveys were conducted over three breeding seasons from 2018 to *** and richness of the bird community was more closely associated with the borders adjacent to the corridors than with the interior of the vineyards,as we initially predicted,although the assemblage of birds did not differ *** than 75%of the registered species consume exclusively or partially ***-friendly management and ecological schemes,together with vegetated corridors provide multiple benefits for biodiversity *** ap-proaches not only minimize the use of agrochemicals but also prioritize soil cover with spontaneous vegetation,which supports a diverse community of insectivorous bird species,potentially contributing to pest control.

关键词： Avian Bayesian analysis Field scale agroecosystem Management Multi-species occupancy model Nature’s contributions to people

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

Laser-optimized Pt-Y alloy nanoparticles embedded in Pt-Y oxide matrix for high stability and ORR electrocatalytic activity

引用

Journal of Energy Chemistry 2024年第5期92卷 508-520页

作者： Riccardo Brandiele andrea Guadagnini Mattia Parnigotto Federico Pini Vito Coviello Denis Badocco Paolo Pastore Gian andrea Rizzi andrea Vittadini Daniel Forrer Vincenzo Amendola Christian Durante Department of Chemical Sciences University of PaduaVia Marzolo 135131 PadovaItaly Istituto di Chimica della Materia Condensata e di Tecnologie per l’Energia ICMATE-CNR via Marzolo 1 I-35131 PadovaItaly

The development of active yet stable catalysts for oxygen reduction reaction(ORR)is still a major issue for the extensive permeation of fuel cells into everyday *** nanostructured Pt catalysts are to date the best available systems in terms of activity,the same is not true for stability,particularly under operating *** this work,Pt_(Х)Y alloy nanoparticles are proposed as active and durable electrocatalysts for ***_(Х)Y nanoalloys are synthesized and further optimized by laser ablation in liquid followed by laser fragmentation in *** novel integrated laser-assisted methodology succeeded in producing Pt_(Х)Y nanoparticles with the ideal size(1000 A g^(-1).At the same time,the nanoalloys are embedded in a fine Pt oxide matrix,which allows a greater stability of the catalyst than the commercial Pt reference,as directly verified on a gas diffusion electrode.

关键词： Electrocatalysis GDE ORR Pt_(2)Y Pt_(3)Y LAL LFL Oxide support Pto Nanoalloys

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

Design methodology of a mini-missile considering flight performance and guidance precision

引用

Journal of Systems Engineering and Electronics 2024年第1期35卷 195-210页

作者： ZHANG Licong GONG Chunlin SU Hua andrea Da Ronch Shaanxi Aerospace Flight Vehicle Design Key Laboratory School of AstronauticsNorthwestern Polytechnical UniversityXi’an 710072China Faculty of Engineering and Physical Sciences University of SouthamptonSouthampton SO171BJUnited Kingdom

The design of mini-missiles(MMs)presents several novel *** stringent mission requirement to reach a target with a certain precision imposes a high guidance *** miniaturization of the size of MMs makes the design of the guidance,navigation,and control(GNC)have a larger-thanbefore impact on the main-body design(shape,motor,and layout design)and its design objective,i.e.,flight *** a trade-off between flight performance and guidance precision,all the relevant interactions have to be accounted for in the design of the main body and the GNC ***,a multi-objective and multidisciplinary design optimization(MDO)is *** pertinent to motor,aerodynamics,layout,trajectory,flight dynamics,control,and guidance are included in the proposed MDO *** optimization problem seeks to maximize the range and minimize the guidance *** problem is solved by using the nondominated sorting genetic algorithm *** optimum design that balances a longer range with a smaller guidance error is ***,lessons learned about the design of the MM and insights into the trade-off between flight performance and guidance precision are given by comparing the optimum design to a design provided by the traditional approach.

关键词： mini-missiles(MMs) guidance navigation and control(GNC)system multi-objective optimization multidisciplinary design optimization(MDO) flight performance guidance precision

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

Life cycle assessment as a prospective tool for sustainable agriculture and food planning at a local level

引用

Geography and Sustainability 2024年第2期5卷 251-264页

作者： andrea Lulovicova Stephane Bouissou UniversitéCôte d’Azur ESPACE Laboratory UMR730098bd Edouard Herriot06200 NiceFrance

Owing to the far-reaching environmental consequences of agriculture and food systems,such as their contribution to climate change,there is an urgent need to reduce their *** and national governments set sustainability targets and implement corresponding ***,critics of the globalized system claim that a territorial administrative scale is better suited to address sustainability ***,at the subnational level,local authorities rarely apply a systemic environmental assessment to enhance their action *** paper employs a territorial life cycle assessment methodology to improve local environmental agri-food *** objective is to identify significant direct and indirect environmental hotspots,their origins,and formulate effective mitigation *** methodology is applied to the administrative department of Finistere,a strategic agricultural region in North-Western *** environmental criteria including climate change,fossil resource scarcity,toxicity,and land use are *** findings reveal that the primary environmental hotspots of the studied local food system arise from indirect sources,such as livestock feed or diesel *** reduction and organic farming conversion emerge as the most environmentally efficient strategies,resulting in a 25%decrease in the climate change ***,the overall modeled impact reduction is insufficient following national objectives and remains limited for the land use *** results highlight the innovative application of life cycle assessment led at a local level,offering insights for the further advancement of systematic and prospective local agri-food ***,they provide guidance for local authorities to enhance the sustainability of planning strategies.

关键词： Environmental analysis Territorial life cycle assessment Prospective scenario Agri-food planning Local food system

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

Application of flame-formed carbon nanoparticle films for ethanol sensing Author links open overlay panel

引用

Particuology 2024年第8期91卷 202-210页

作者： Pegah Darvehi Luca Basta Mario Commodo Patrizia Minutolo andrea D'Anna Istituto di Scienze e Tecnologie per l’Energia e la MobilitàSostenibili Consiglio Nazionale delle RicercheP.le Tecchio 8080125NapoliItaly Dipartimento di Ingegneria Chimica dei Materiali e della Produzione IndustrialeUniversitàdegli Studi di Napoli Federico IIP.le Tecchio 8080125NapoliItaly

Carbon nanoparticles(CNPs)have received considerable attention due to their exceptional qualities and *** unique physical and chemical characteristics make them extremely intriguing as materials for numerous high-potential applications,such as electronics and gas *** study focused on producing carbon-based nanomaterial devices by deposition of flame-formed carbon nanoparticles on a suitable substrate and investigating their gas-sensing *** were produced in a fuel-rich laminar premixed ethylene/air flame and the collected CNP film was morphologically and electrically *** electrical conductivity of the film was investigated as a function of ethanol concentration and amount of deposited ***,CNP films exhibited high sensitivity to ambient ethanol gas concentrations,and rapid recovery times at room temperature,and showed a sensitivity increasing with the amount of deposited material and the surface *** findings demonstrate the high potential of combustion-generated CNPs as building materials for low-cost and portable ethanol sensors.

关键词： Flame synthesis Carbon nanoparticles Soot Nanostructured thin film Optical and electrical characterization Atomic force microscopy Sensors

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

Grasslands Response to Livestock Grazing Intensity in the Austral Pampas (Argentina): Testing the Intermediate Disturbance Hypothesis

引用

PHYTON-INTERNATIONAL JOURNAL OF EXPERIMENTAL BOTANY 2024年第8期93卷 2037-2050页

作者： de Villalobos, Ana Elena Long, Maria andrea Consejo Nacl Invest Cient & Tecn CERZOS Grp Invest Ecosistemas Pastizal RA-8000 Bahia Blanca Buenos Aires Argentina Univ Nacl Sur Dept Biol Bioquim & Farm RA-8000 Bahia Blanca Buenos Aires Argentina

Livestock grazing has a significant impact on natural grasslands, with approximately one-third of the world's land area dedicated to this industry. Around 20% of global grasslands are highly degraded due to overgrazing, affecting their productivity and conservation capacity. Best practices are required to ensure sustainable livestock production that supports biodiversity. The Intermediate Disturbance Hypothesis (IDH) suggests that environments with moderate levels of disturbance exhibit a higher species diversity. Moderate grazing can reduce the dominance of certain species, thereby enhancing plant diversity. However, concerns arise regarding the increase of exotic and unpalatable species under moderate grazing levels, complicating grassland conservation efforts. The impact of livestock grazing on the functional structure of grasslands depends on factors such as grazing intensity, livestock species, and environmental conditions. Variations in grazing intensity may increase specific and functional diversity under moderate grazing, potentially masking the presence of invasive exotic species. In the Austral Pampas (Pampean phytogeographic province, Buenos Aires, Argentina), grasslands face various pressures from domestic livestock grazing that endanger their integrity if not properly managed. Therefore, our study aims to investigate potential differences in species richness and diversity, functional diversity, exotic plant abundance, and the number and distribution of plant functional groups across varying grazing intensities. The IDH is utilized as a tool to regulate livestock pressure for grassland conservation. Species and functional diversity indices were used to assess the impact of grazing on grassland diversity. Moderate grazing increased species and functional diversity, while intensively grazed or ungrazed areas showed reduced diversity. Livestock presence influenced the balance between native and exotic plants, with ungrazed areas having higher native plant a

关键词： Natural grasslands grazing effects disturbance speci fi c and functional diversity FERAL HORSES DIVERSITY INVASION VEGETATION PLANTS FIRE RAIN

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

Model Change Active Learning in Graph-Based Semi-supervised Learning

引用

Communications on Applied Mathematics and Computation 2024年第2期6卷 1270-1298页

作者： Kevin S.Miller andrea L.Bertozzi Department of Mathematics University of CaliforniaLos Angeles520 Portola PlazaLos AngelesCA 90095USA

Active learning in semi-supervised classification involves introducing additional labels for unlabelled data to improve the accuracy of the underlying classifier.A challenge is to identify which points to label to best improve performance while limiting the number of new labels."Model Change"active learning quantifies the resulting change incurred in the classifier by introducing the additional label(s).We pair this idea with graph-based semi-supervised learning(SSL)methods,that use the spectrum of the graph Laplacian matrix,which can be truncated to avoid prohibitively large computational and storage *** consider a family of convex loss functions for which the acquisition function can be efficiently approximated using the Laplace approximation of the posterior *** show a variety of multiclass examples that illustrate improved performance over prior state-of-art.

关键词： Active learning Graph-based methods Semi-supervised learning(SSL) Graph Laplacian

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

Scalable orthogonal delay-division multiplexed OEO artificial neural network trained for TI-ADC equalization

引用

Photonics Research 2024年第1期12卷 85-105页

作者： andrea ZAZZI ARKA DIPTA DAS LUKAS HüSSEN RENATO NEGRA JEREMY WITZENS Institute of Integrated Photonics RWTH Aachen University52074 AachenGermany Chair of High-Frequency Electronics RWTH Aachen University52074 AachenGermany

We propose a new signaling scheme for on-chip optical-electrical-optical artificial neural networks that utilizes orthogonal delay-division multiplexing and pilot-tone-based self-homodyne *** scheme offers a more efficient scaling of the optical power budget with increasing network *** simulations,based on220 nm silicon-on-insulator silicon photonics technology,suggest that the network can support 31×31 neurons,with 961 links and freely programmable weights,using a single 500 m W optical comb and a signal-to-noise ratio of 21.3 d B per ***,it features a low sensitivity to temperature fluctuations,ensuring that it can be operated outside of a laboratory *** demonstrate the network’s effectiveness in nonlinear equalization tasks by training it to equalize a time-interleaved analog-to-digital converter(ADC)architecture,achieving an effective number of bits over 4 over the entire 75 GHz ADC *** anticipate that this network architecture will enable broadband and low latency nonlinear signal processing in practical settings such as ultra-broadband data converters and real-time control systems.

关键词： network delay artificial

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

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：