检索结果-南通市图书馆

How toxic are gold nanoparticles？ The state-of-the-art

在线全文

学校读者我要写书评

暂无评论

Nano Research 2015年第6期8卷 1771-1799页

作者： Ilaria Fratoddi Iole Venditti Cesare cametti Maria Vittoria Russo dipartimento di Chimica Universita' di Roma 'La Sapienza' Piazzale A. Moro 5 1-00185 Rome Italy dipartimento di fisica and INFM CNR-SOFT Universita' di Roma 'La Sapienza' Piazzale A. Moro 51-00185 Rome Italy

With the growing interest in the applications of gold nanoparticles in biotechnology and their physiological effects, possible toxicity of gold nanoparticles is becoming an increasingly important issue. A large number of studies carried out over the past few years under a variety of experimental conditions and following different protocols have produced conflicting results, leading to divergent views about the actual safety of gold nanoparticles in human applications. This work is intended to provide an overview of the most recent experimental results and thereby summarize current state-of-the-art. Rather than presenting a comprehensive review of the available literature in this field, which would be impractically broad, we have selected representative examples of both in vivo and in vitro studies, which clearly demonstrate the need for urgent and rigorous standardization of experimental protocols. Despite their significant potential, the safety of gold nanoparticles is highly controversial at this time, and important concerns have been raised that need to be properly addressed. Factors such as shape, size, surface charge, coating, and surface functionalization are expected to influence the interactions of particles with biological systems to a different extent, resulting in different outcomes and influencing the potential of gold nanoparticles for biomedical applications. Moreover, despite continuous attempts to establish a correlation between structure of the particles and their interactions with biological systems, we are still far from elucidating the toxicological profile of gold nanoparticles in an indisputable manner. This review is intended to contribute towards this goal, offering a number of suggestions on how to achieve the systematization of data on the most relevant physico-chemical parameters, which govern and control the toxicity of ~old nanot^articles at cellular and whole-organism levels.

关键词： gold nanoparticles nanospheres nanorods nanocages nanostars toxicity

Exact Electronic Bands for a Periodic Pschl–Teller Potential

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2016年第11期65卷 491-495页

作者： Francesco di Filippo Canio Noce CNR-SPIN 1-84084 Fisciano(Salerno)Italy and Dipartimento di Fisica"E.R.Caianiello"Universit~di Salerno1-84084Fisciano(Salerno)Italy

We show that supersymmetry is a simple but powerful tool to exactly solve quantum mechanics problems. Here, the supersymmetric approach is used to analyse a quantum system with periodic Poschl-Teller potential, and to... 详细信息

关键词： supersymmetric quantum mechanics periodic Poschl-Teller potential SchrSdinger equation en-ergy bands

Two-flavor hybrid stars with the Dyson-Schwinger quark model

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2017年第11期41卷 110-116页

作者：魏金标陈欢 H.-J.Schulze School of Mathematics and Physics China University of Geosciences INFN Sezione di Catania Dipartimento di FisicaUniversitá di Catania

We study the properties of two-flavor quark matter in the Dyson-Schwinger model and investigate the possible consequences for hybrid neutron stars,with particular regard to the two-solar-mass *** find that with some extreme values of the model parameters,the mass fraction of two-flavor quark matter in heavy neutron stars can be as high as 30 percent and the possible energy release during the conversion from nucleonic neutron stars to hybrid stars can reach 1052 erg.

关键词： hybrid stars quark matter equation of state Dyson-Schwinger equations

A Second Order Finite-difference Ghost-Point Method for Elasticity Problems on Unbounded Domains with Applications to Volcanology

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2014年第9期16卷 983-1009页

作者： Armando Coco Gilda Currenti Ciro Del Negro Giovanni Russo dipartimento di Scienze della Terra e Geoambientali Universita di Bari Aldo MoroBariItaly. Bristol University Queens RoadBristol BS81RJUnited Kingdom. Istituto Nazionale di Geofisica e Vulcanologia Italy. dipartimento di Matematica e Informatica Universita di CataniaCataniaItaly

We propose a finite-difference ghost-point approach for the numerical solution of Cauchy-Navier equations in linear elasticity problems on arbitrary unbounded *** technique is based on a smooth coordinate transformation,which maps an unbounded domain into a unit *** geometries are defined by suitable level-set *** equations are discretized by classical nine-point stencil on interior points,while boundary conditions and high order reconstructions are used to define the field variables at ghost-points,which are grid nodes external to the domain with a neighbor inside the *** linear system arising from such discretization is solved by a multigrid *** approach is then applied to solve elasticity problems in volcanology for computing the displacement caused by pressure *** method is suitable to treat problems in which the geometry of the source often changes(explore the effects of different scenarios,or solve inverse problems in which the geometry itself is part of the unknown),since it does not require complex re-meshing when the geometry is *** numerical tests are successfully performed,which asses the effectiveness of the present approach.

关键词： Linear elasticity Cauchy-Navier equations ground deformation unbounded domain coordinate transformation method Cartesian grid ghost points level-set methods multigrid.

Characterisation of Photocathodes Based on Pb Thin Film Deposited by UV Pulsed Laser Ablation

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 Materials Science & Technology 2014年第1期30卷 37-40页

作者： Francisco Gontad Antonella Lorusso Giancarlo Gatti Massimo Ferrario Laura Gioia Passione Luana Persano Nicola Lovergine Alessio Perrone Istituto Nazionale di fisica Nucleare e Università del Salento Università del Salento Dipartimento di Matematica e Fisica "E.De Giorgi" Laboratori Nazionali di Frascati Istituto Nazionale di Fisica Nucleare Center for Biomolecular Nanotechnologies Istituto Italiano di Tecnologia dipartimento di Ingegneria dell'Innovazione Università del Salento National Nanotechnology Laboratory(NNL)

This work deals with the deposition of lead （Pb） thin films by the UV pulsed laser ablation technique, for their further use as photocathode devices in superconducting radio frequency guns. Scanning electron microscopy and atomic force microscopy analyses were performed to study the morphological features of Pb thin films deposited on Si （100） and Nb substrates. The films showed a granular structure with a nearly fully covered surface only for that one deposited on Nb substrate. X-ray diffraction measurements indicate the growth of polycrystalline Pb thin films with a preferential orientation along （111） planes. Results of the photoemission performance of Pb thin film deposited on Nb substrate showed a very encouraging average value of quantum efficiency of 6 x 10-5 through a single-photon absorption process, promoting further studies in the realisation of Pb photocathodes by this technique.

关键词： Pulsed laser deposition Lead thin film Metallic photocathodes Quantum efficiency

Groups with Finitely Many Homomorphic Images of Finite Rank

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2016年第2期23卷 181-187页

作者： Francesco de Giovanni Alessio Russo dipartimento di Matematica e Applicazioni Universitg di Napoli Federico II Complesso Universitario Monte S. Angelo Via Cintia 1-80126 Napoli Italy dipartimento di Matematica e fisica Seconda Universitg di Napoli Via Lincoln 5 1-81100 Caserta Italy

A group is called a Cernikov group if it is abelian-by-finite and satisfies the minimal condition on subgroups. A new characterization of Cernikov groups is given here, by proving that in a suitable large class of generalised soluble groups they coincide with the groups having only finitely many homomorphic images of finite rank （up to isomorphisms） and admitting an ascending normal series whose factors have finite rank.

关键词： Prufer rank Cernikov group homomorphic image

Thermally reconfigurable quantum photonic circuits at telecom wavelength by femtosecond laser micromachining

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2015年第1期4卷 72-78页

作者： Fulvio Flamini Lorenzo Magrini Adil S Rab Nicolo Spagnolo Vincenzo D’Ambrosio Paolo Mataloni Fabio Sciarrino Tommaso Zandrini Andrea Crespi Roberta Ramponi Roberto Osellame dipartimento di fisica-Sapienza Universita di Roma P.le Aldo Moro 5I-00185 RomaItaly Istituto di Fotonica e Nanotecnologie-Consiglio Nazionale delle Ricerche(IFNCNR) P.za Leonardo da Vinci32I-20133 MilanoItaly dipartimento di fisica-Politecnico di Milano P.za Leonardo da Vinci32I-20133 MilanoItaly

The importance of integrated quantum photonics in the telecom band is based on the possibility of interfacing with the optical network infrastructure that was developed for classical *** this framework,femtosecond laser-written integrated photonic circuits,which have already been assessed for use in quantum information experiments in the 800-nm wavelength range,have great *** fact,these circuits,being written in glass,can be perfectly mode-matched at telecom wavelength to the in/out coupling fibers,which is a key requirement for a low-loss processing node in future quantum optical *** addition,for several applications,quantum photonic devices must be dynamically ***,we experimentally demonstrate the high performance of femtosecond laser-written photonic circuits for use in quantum experiments in the telecom band,and we demonstrate the use of thermal shifters,which were also fabricated using the same femtosecond laser,to accurately tune such ***-of-the-art manipulation of single-and two-photon states is demonstrated,with fringe visibilities greater than 95%.The results of this work open the way to the realization of reconfigurable quantum photonic circuits based on this technological platform.

关键词： femtosecond laser micromachining integrated quantum photonics thermal shifters tunable optical circuits

Infrared synchrotron radiation spectroscopy and microspectroscopy: new tools for interdisciplinary applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2003年第2期14卷 93-103页

作者： A.MARCELLI P.CALVANI Laboratori Nazionali di Frascati -INFN Via E. Fermi 4000044 FrascatiItalyIstituto Nazionale di Fisica della Materia and Dipartimento di FisicaUniversit La SapienzaP.le A.Moro20O185 RomaItaly

Synchrotron radiation sources, whose number is steadily increasing, are undoubtedly the most powerful and brilliant sources in the X-ray range. Although the synchrotron emission covers with high brilliance also the infrared region, its use in this energy range has developed at a much slower rate. Nowadays, after a couple of decades of attempts, the aim of extending the unique performances of the synchrotron source to the infrared domain is achieved by several dedicated beamlines in different countries. With their high-brilliance, polarized and broad-band radiation one may perform experiments that are out of the range of conventional sources from the near-IR up to the far-IR range.

关键词：红外同步加速器辐射光谱微波光谱 Fourier变换

Efficient GW calculations in two dimensional materials through a stochastic integration of the screened potential

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2023年第1期9卷 1912-1919页

作者： Alberto Guandalini Pino D’Amico Andrea Ferretti Daniele Varsano S3 Centre Istituto NanoscienzeCNRVia Campi 213/aModenaItaly Present address:dipartimento di fisica Universitàdi Roma La SapienzaPiazzale Aldo Moro 5I-00185 RomaItaly

Many-body perturbation theory methods,such as the G0W0 approximation,are able to accurately predict quasiparticle(QP)properties of several classes of ***,the calculation of the QP band structure of two-dimensional(2D)semiconductors is known to require a very dense BZ sampling,due to the sharp q-dependence of the dielectric matrix in the long-wavelength limit(q→0).In this work,we show how the convergence of the QP corrections of 2D semiconductors with respect to the BZ sampling can be drastically improved,by combining a Monte Carlo integration with an interpolation scheme able to represent the screened potential between the calculated grid *** method has been validated by computing the band gap of three different prototype monolayer materials:a transition metal dichalcogenide(MoS2),a wide band gap insulator(hBN)and an anisotropic semiconductor(phosphorene).The proposed scheme shows that the convergence of the gap for these three materials up to 50meV is achieved by using k-point grids comparable to those needed by DFT calculations,while keeping the grid uniform.

关键词： materials integration potential