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Redox behavior of gold supported on ceria and ceria-zirconia based catalysts

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Journal of Rare Earths 2009年第2期27卷 196-203页

作者： Michela Vicario Jordi Llorca Marta Boaro Carla de Leitenburg Alessandro Trovarelli Dipartimento di Scienze e Tecnologie Chimiche Università di UdineVia del Cotonificio 10833100 UdineItaly Institut de Tècniques Energètiques Universitat Politècnica de CatalunyaDiagonal 647ed. ETSEIB08028 BarcelonaSpain

A series of gold-based catalysts were prepared by deposition precipitation or incipient wetness impregnation on CexZ1-xO2 solid solutions （0.28≤x≤1.00）. The morphological and structural characterization of these catalysts were carried out with X-ray diffraction, trans- mission electron microscopy （TEM） analysis and physical adsorption technique, and their redox properties were studied by temperature programmed reduction using both H2 and CO as probe molecules. Two cycles of oxidation/reduction were carried out in order to evaluate the effects of redox aging and gold sintering on the oxygen exchange capability. As observed with other noble metals, gold enhanced and promoted the ceria reduction at lower temperatures. Reduction by CO was shown to be dependent on the fine dispersion of gold and to be nega- tively affected by the ageing process more than reduction with hydrogen. This might have implications in reactions like water gas shift and CO-PROX which involve CO as a main reactant.

关键词： gold ceria zirconia catalysis reduction behaviour nanoparticles temperature programmed reduction X-ray diffraction rare earths

Large-area patterning of substrate-conformal MoS2 nano-trenches

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Nano Research 2019年第8期12卷 1851-1854页

作者： Christian Martella Luca Ortolani Elena Cianci Alessio Lamperti Vittorio Morandi Alessandro Molle IMM-CNR via C. Olivetti 2Agrate Brianza (MB) 1-20864Italy ISC-CNR U.O.S. SapienzaRoma 1-00185Italy IMM-CNR via Gobetti 101Bologna (BO) 1-40129Italy

Within the class of two-dimensional materials, transition metal dichalcogenides (TMDs), are extremely appealing for a variety of technological applications. Moreover, the manipulation of the layered morphology at the nanoscale is a knob for further tailoring their physical and chemical properties towards target applications. Here, the combination of atomic layer deposition (ALD) and chemical vapour deposition (CVD) is presented as a general approach for the fabrication of TMD layers arranged in arbitrary geometry at the nanoscale. Indeed, following such all-chemical based approach, high-resolution electron microscopy shows the conformal growth of MoS2 to nano-trench pattern obtained in SiO2 substrates on large area. Growth is uniform not only in the flat region of the pattern but also at the hinges and throughout vertical faces, without rupture, all along the rectangular shape profile of the trenches. Furthermore, MoS2 bending dramatically affects the electron-phonon coupling as demonstrated by resonant Raman scattering. The proposed approach opens the door to the on-demand manipulation of the TMDs properties by large-scale substrate pattern design.

关键词： two-dimensional (2D) materials transition metal dichalcogenides nano-trenches conformal growths high-resolution electron microscopy

Laser generation of iron-doped silver nanotruffles with magnetic and plasmonic properties

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Nano Research 2015年第12期8卷 4007-4023页

作者： Vincenzo Amendola Stefano Scaramuzza Stefano Agnoli Gaetano Granozzi Moreno Meneghetti Giulio Campo Valentina Bonanni Francesco Pineider Claudio Sangregorio Paolo Ghigna Stefano Polizzi Piero Riello Stefania Fiameni Luca Nodari Department of Chemical Sciences Universita di Padova Padova 1-35131 Italy Department of Chemistry University of Florence & INSTM Florence 1-50019 Italy ICCOM-CNR Sesto Fiorentino Florence 1-50019 Italy Department of Chemistry Universitta di Pavia Pavia 1-27100 Italy Department of Molecular Sciences and Nanosystems Universita Ca' Foscari Venezia and INSTM UdR Venezia Venezia-Mestre 1-30172 Italy CNR - IENI Padova 1-35127 Italy

A frontier topic in nanotechnology is the realization of multifunctional nanoparticles （NPs） via the appropriate combination of different elements of the periodic table. The coexistence of Fe and Ag in the same nanostructure, for instance, is interesting for nanophotonics, nanomedicine, and catalysis. However, alloying of Fe and Ag is inhibited for thermodynamic reasons. Here, we describe the synthesis of Fe-doped Ag NPs via laser ablation in liquid solution, bypassing thermodynamics constraints. These NPs have an innovative structure consisting of a scaffold of face-centered cubic metal Ag alternating with disordered Ag-Fe alloy domains, all arranged in a truffle-like morphology. The Fe-Ag NPs exhibit the plasmonic properties of Ag and the magnetic response of Fe-containing phases, and the surface of the Fe-Ag NPs can be functionalized in one step with thiolated molecules. Taking advantage of the multiple properties of Fe-Ag NPs, the magnetophoretic amplification of plasmonic properties is demonstrated with proof-of-concept surface-enhanced Raman scattering and photothermal heating experiments. The synthetic approach is of general applicability and virtually permits the preparation of a large variety of multi-element NPs in one step.

关键词： silver nanotruffles iron nanoparticles laser ablation laser ablation synthesis in solution(LASiS) nanoalloys

Persistent pollutants and the patchiness of urban green areas as drivers of genetic richness in the epiphytic moss Leptodon smithii

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Journal of Environmental Sciences 2014年第12期26卷 2493-2499页

作者： Valeria Spagnuolo Flavia De Nicola Stefano Terracciano Roberto Bargagli Daniela Baldantoni Fabrizio Monaci Anna Alfani Simonetta Giordano Department of Biology University of Naples Federico II via Cinthia 4 Naples 80126 Italy Department of Science and Technology University of Sannio Via Port'Arsa 11 Benevento 82100 Italy Department of Environmental Sciences University of Siena Via Mattioli 4 Siena 53100 Italy Department of Chemistry and Biology University of Salerno Via Giovanni Paolo II 132 84084 Fisciano SA Italy

We determined genetic variation and metal and polycyclic aromatic hydrocarbon concentrations in Leptodon smithii moss collected in holm oak stands at cities, outskirts and remote areas of Campania and Tuscany（Italy） to investigate if anthropogenic pressure（pollutant emissions and land use change） affects moss genetic richness. In both regions, metal and polycyclic aromatic hydrocarbon concentrations reflected the trend urban 〉 outskirts 〉 remote areas, excepting Tuscany remote site. In both regions,the moss gene diversity increased from urban to remote areas. The findings suggest the extent and the fragmentation of urban green areas, as drivers of moss genetic richness.

关键词： Gene diversity Metals Polycyclic aromatic hydrocarbons Habitat fragmentation Environmental disturbance

Efficient light harvesting from flexible perovskite solar cells under indoor white light-emitting diode illumination

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Nano Research 2017年第6期10卷 2130-2145页

作者： Giulia Lucarelli Francesco Di Giacomo Valerio Zardetto Mariadriana creatore Thomas M. Brown Centre for Hybrid and Organic Solar Energy (CHOSE) Department of Electronic Engineering University of Rome Tor Vergata Via del Politecnico 100133 Rome Italy Hoist Centre/TNO - Solliance 5655AE Eindhoven the Netherlands Department of Applied Physics Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven the Netherlands

This is the first report of an investigation on flexible perovskite solar cells for artificial light harvesting by using a white light-emitting diode （LED） lamp as a light source at 200 and 400 Ix, values typically found in indoor environments. Flexible cells were developed using either low-temperature sol-gel or atomic- layer-deposited compact layers over conducting polyethylene terephthalate （PET） substrates, together with ultraviolet （UV）-irradiated nanoparticle TiO2 scaffolds, a CH3NHBPbI3xClx perovskite semiconductor, and a spiro-MeOTAD hole transport layer. By guaranteeing high-quality carrier blocking （via the 10-40 nm-thick com- pact layer） and injection （via the nanocrystalline scaffold and perovskite layers） behavior, maximum power conversion efficiencies （PCE） and power densities of 10.8% and 7.2 pW-cm-2, respectively, at 200 lx, and 12.1% and 16.0 -tW＇cm-2, respectively, at 400 lx were achieved. These values are the state-of-the-art, comparable to and even exceeding those of flexible dye-sensitized solar cells under LED lighting, and significantly greater than those for flexible amorphous silicon, which are currently the main flexible photovoltaic technologies commercially considered for indoor applications. Furthermore, there are significant margins of improvement for reaching the best levels of efficiency for rigid glass-based counterparts, which we found was a high of PCE -24% at 400 lx. With respect to rigid devices, flexibility brings the advantages of being low cost, lightweight, very thin, and COlfformal, which is especially important for seamless integration in indoor environments.

关键词： flexible perovskite solar cells indoor light harvesting atomic layer deposition nanocrystalline scaffolds flexible photovoltaics energy harvesting

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

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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

Groups Whose Proper Subgroups of Infinite Rank Have Polycyclic Conjugacy Classes

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Algebra Colloquium 2015年第2期22卷 181-188页

作者： Francesco de Giovanni Marco Trombetti Dipartimento di Matematica e Applicazioni Universita di Napoli Federico II Complesso Universitario Monte S. Angelo Via Cintia I- 80126 Napoli Italy

A group G is called a PC-group if the factor group G/CG（〈X）^G） is polycyclic for each element x of G. It is proved here that if G is a group of infinite rank whose proper subgroups of infinite rank have the property PC, then G itself is a PC-group, provided that G has an abelian non-trivial homomorphic image. Moreover, under the same assumption, a complete classification of minimal non-PC groups is obtained.

关键词： PC-group minimal non-PC group group of infinite rank

Small heat shock protein B8:from cell functions to its involvement in diseases and potential therapeutic applications

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Neural Regeneration Research 2025年第10期20卷 2872-2886页

作者： Marta Chierichetti Riccardo Cristofani Valeria Crippa Veronica Ferrari Marta Cozzi Elena Casarotto Paola Pramaggiore Laura Cornaggia Guglielmo Patelli Ali Mohamed Margherita Piccolella Mariarita Galbiati Paola Rusmini Barbara Tedesco Angelo Poletti Laboratory of Experimental Biology Dipartimento di Scienze Farmacologiche e Biomolecolari“Rodolfo Paoletti”(DiSFeB)Universitàdegli Studi di MilanoMilanItaly

Heat shock protein family B(small)member 8(HSPB8)is a 22 kDa ubiquitously expressed protein belonging to the family of small heat shock ***8 is involved in various cellular mechanisms mainly related to proteotoxic stress response and in other processes such as inflammation,cell division,and ***8 binds misfolded clients to prevent their aggregation by assisting protein refolding or degradation through chaperone-assisted selective *** line with this function,the pro-degradative activity of HSPB8 has been found protective in several neurodegenerative and neuromuscular diseases characterized by protein misfolding and *** cancer,HSPB8 has a dual role being capable of exerting either a pro-or an anti-tumoral activity depending on the pathways and factors expressed by the model of cancer under ***,HSPB8 exerts a protective function in different diseases by modulating the inflammatory response,which characterizes not only neurodegenerative diseases,but also other chronic or acute conditions affecting the nervous system,such as multiple sclerosis and intracerebellar *** note,HSPB8 modulation may represent a therapeutic approach in other neurological conditions that develop as a secondary consequence of other *** is the case of cognitive impairment related to diabetes mellitus,in which HSPB8 exerts a protective activity by assuring mitochondrial *** review aims to summarize the diverse and multiple functions of HSPB8 in different pathological conditions,focusing on the beneficial effects of its ***-based and alternative therapeutic approaches targeting HSPB8 and its regulated pathways will be discussed,emphasizing how new strategies for cell and tissue-specific delivery represent an avenue to advance in disease treatments.

关键词： aggregation autophagy cancer chaperone chaperone-assisted selective autophagy cognitive impairment HSPB8 neuroinflammation neuromuscular diseases therapy

An Iterative Multigrid Regularization Method for Toeplitz Discrete Ill-Posed Problems

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Numerical Mathematics(Theory,Methods and Applications) 2012年第1期5卷 43-61页

作者： Marco Donatelli Dipartimento di Fisica e Matematica Universitàdell’InsubriaVia Valleggio11Como 22100Italia

Iterative regularization multigrid methods have been successful applied to signal/image deblurring *** zero-Dirichlet boundary conditions are imposed the deblurring matrix has a Toeplitz structure and it is potentially full.A crucial task of a multilevel strategy is to preserve the Toeplitz structure at the coarse levels which can be exploited to obtain fast *** smoother has to be an iterative regularization *** grid transfer operator should preserve the regularization property of the *** paper improves the iterative multigrid method proposed in[11]introducing a wavelet soft-thresholding denoising *** postsmoother avoids the noise amplification that is the cause of the semi-convergence of iterative regularization methods and reduces ringing *** resulting iterative multigrid regularization method stabilizes the iterations so that and imprecise(over)estimate of the stopping iteration does not have a deleterious effect on the computed *** examples of signal and image deblurring problems confirm the effectiveness of the proposed method.

关键词： Multigrid methods Toeplitz matrices discrete ill-posed problems