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Detection of Proper Motion in OQ208

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Chinese Physics Letters 2000年第4期17卷 307-309页

作者：刘祥 C.Stanghellini D.Dallacasa M.Bondi Urumqi Astronomical Observatoryj National Astronomical Observatories Chinese Academy of SciencesUrumqi 830011 istituto di Radioastronomia del cnrt Notot Italy Uhiversita di Bolognaf Italy istituto di Radioastronomia del cnr Bolognat Italy

We report on an ongoing work aimed to detect the separation speed of the two hot-spots of the compact symmetric object *** images at 8.4 GHz taken in 6 epoches between 1994 and 1997 we obtain an estimate of 0.058±-0.038 mas/year as the relative motions between two components of the radio *** the red-shift of OQ208 I mas correspond to 1pc,thus we obtain a projected jet speed of 0.095±*** an inclination of 45°between the jets and the line of sight,we have an actual jet velocity of 0.134±0.088c and therefore the kinematic age of the source is so young of 320±210 years.

关键词： OQ epoch separation

The HEPD particle detector of the CSES satellite mission for investigating seismo-associated perturbations of the Van Allen belts

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Science China(Technological Sciences) 2018年第5期61卷 643-652页

作者： AMBROSI Giovanni BARTOCCI Simona BASARA Laurent BATTISTON Roberto BURGER William J. CARFORA Luca CASTELLINI Guido CIPOLLONE Piero CONTI Livio CONTIN Andrea DE DONATO Cinzia DE SANTIS Cristian FOLLEGA Francesco M. GUANDALINI Cristina IONICA Maria IUPPA Roberto LAURENTI Giuliano LAZZIZZERA Ignazio LOLLI Mauro MANEA Christian MARCELLI Laura MASCIANTONIO Giuseppe MERGE Matteo OSTERIA Giuseppe PACINI Lorenzo PALMA Francesco PALMONARI Federico PANICO Beatrice PATRIZII Laura PERFETTO Francesco PICOZZA Piergiorgio POZZATO Michele PUEL Matteo RASHEVSKAYA Irina RICCI Ester RICCI Marco RICCIARINI Sergio Bruno SCOTTI Valentina SOTGIU Alessando SPARVOLI Roberta SPATARO Bruno VITALE Vincenzo istituto Nazionale di Fisica Nucleare (infn) Sezione di Perugia Perugia 06123 Italy Uninettuno University Rome 00186 Italy istituto Nazionale di Fisica Nucleare (infn) Sezione di Roma Tor Vergata Rome 00133 Italy istituto Nazionale di Fisica Nucleare (infn) TIFPA Povo (TN) 38123 Italy dipartimento di Fisica Universita di Trento Povo (TN) 38123 Italy dipartimento di Fisica Universita di Roma Tor Vergata Rome 00133 Italy IFAC-cnr Sesto Fiorentino (FI) 50019 Italy dipartimento di Fisica e Astronomia Universita di Bologna Bologna 40127 Italy istituto Nazionale di Fisica Nucleare (infn) Sezione di Bologna Bologna 40127 Italy istituto Nazionale di Fisica Nucleare (infn) Sezione di Napoli Naples 80126 Italy istituto Nazionale di Fisica Nucleare (infn) LNE Frascati (RM) 00044 Italy Agenzia Spaziale Italiana (ASI) SSDC Rome 00133 Italy

CSES(China Seismo-Electromagnetic Satellite) is a mission developed by CNSA(Chinese National Space Administration) and ASI(Italian Space Agency), to investigate the near-Earth electromagnetic, plasma and particle environment, for studying the seismo-associated disturbances in the ionosphere-magnetosphere transition zone. The anthropogenic and electromagnetic noise,as well as the natural non-seismic electromagnetic emissions is mainly due to tropospheric activity. In particular, the mission aims to confirming the existence of possible temporal correlations between the occurrence of earthquakes for medium and strong magnitude and the observation in space of electromagnetic perturbations, plasma variations and precipitation of bursts with highenergy charged particles from the inner Van Allen belt. In this framework, the high energy particle detector(HEPD) of the CSES mission has been developed by the Italian LIMADOU Collaboration. HEPD is an advanced detector based on a tower of scintillators and a silicon tracker that provides good energy and angular resolution and a wide angular acceptance, for electrons of 3–100 Me V, protons of 30–200 Me V and light nuclei up to the oxygen. CSES satellite has been launched on February 2^(nd), 2018 from the Jiuquan Satellite Launch Center(China).

关键词： earthquake seismic-precursors particle detector Van Allen belts magnetosphere ionosphere space weather cosmic rays

Fault on-off versus strain rate and earthquakes energy

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Geoscience Frontiers 2015年第2期6卷 265-276页

作者： C.Doglioni S.Barba E.Carminati F.Riguzzi dipartimento di Scienze della Terra Università Sapienza istituto di Geologia Ambientale e Geoingegneria CNR istituto Nazionale di Geofisica e Vulcanologia

We propose that the brittle-ductile transition （BDT） controls the seismic cycle. In particular, the movements detected by space geodesy record the steady state deformation in the ductile lower crust, whereas the stick-slip behavior of the brittle upper crust is constrained by its larger friction. GPS data allow analyzing the strain rate along active plate boundaries. In all tectonic settings, we propose that earthquakes primarily occur along active fault segments characterized by relative minima of strain rate, segments which are locked or slowly creeping. We discuss regional examples where large earthquakes happened in areas of relative low strain rate. Regardless the tectonic style, the interseismic stress and strain pattern inverts during the coseismic stage. Where a dilated band formed during the interseismic stage, this will be shortened at the coseismic stage, and vice-versa what was previously shortened, it will be dilated. The interseismic energy accumulation and the coseismic expenditure rather depend on the tectonic setting （extensional, contractional, or strike-slip）. The gravitational potential energy dominates along normal faults, whereas the elastic energy prevails for thrust earthquakes and performs work against the gravity force. The energy budget in strike-slip tectonic setting is also primarily due elastic energy. Therefore, precursors may be different as a function of the tectonic setting. In this model, with a given displacement, the magnitude of an earthquake results from the coseismic slip of the deformed volume above the BDT rather than only on the fault length, and it also depends on the fault kinematics.

关键词： Earthquake generation mode Strain rate Brittle-ductile transition Earthquake energy

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

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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

High-speed flow of interacting organic polaritons

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Light(Science & Applications) 2016年第1期5卷 235-240页

作者： Giovanni Lerario Dario Ballarini Antonio Fieramosca Alessandro Cannavale Armando Genco Federica Mangione Salvatore Gambino Lorenzo Dominici Milena De Giorgi Giuseppe Gigli Daniele Sanvitto cnr NANOTEC-istituto di Nanotecnologia Via Monteroni73100 LecceItaly dipartimento di matematica e fisica‘Ennio De Giorgi’ Universitàdel Salento73100 LecceItaly

The strong coupling of an excitonic transition with an electromagnetic mode results in composite quasi-particles called exciton polaritons,which have been shown to combine the best properties of their individual components in semiconductor ***,the physics and applications of polariton flows in organic materials and at room temperature are still unexplored because of the poor photon confinement in such ***,we demonstrate that polaritons formed by the hybridization of organic excitons with a Bloch surface wave are able to propagate for hundreds of microns showing remarkable third-order nonlinear interactions upon high injection *** findings pave the way for the study of organic nonlinear light–matter fluxes and for a technologically promising route of the realization of dissipation-less on-chip polariton devices operating at room temperature.

关键词： optical nonlinearity organic materials polaritons surface waves 2D optics

Planarized THz quantum cascade lasers for broadband coherent photonics

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Light(Science & Applications) 2022年第12期11卷 3098-3108页

作者： Urban Senica Andres Forrer Tudor Olariu Paolo Micheletti Sara Cibella Guido Torrioli Mattias Beck Jerome Faist Giacomo Scalari Quantum Optoelectronics Group Institute of Quantum ElectronicsETH Zurich8093 ZürichSwitzerland istituto di Fotonica e Nanotecnologie CNRVia del Fosso del Cavaliere 10000133 RomeItaly

Recently,there has been a growing interest in integrated THz photonics for various applications in communications,spectroscopy and *** present a new integrated photonic platform based on active and passive elements integrated in a double-metal,high-confinement waveguide layout planarized with a low-loss *** extended top metallization keeps waveguide losses low while improving dispersion,thermal and RF properties,as it enables to decouple the design of THz and microwave ***-running on-chip quantum cascade laser combs spanning 800 GHz,harmonic states with over 1.1 THz bandwidth and RF-injected broadband incoherent states spanning over nearly 1.6 THz are observed using a homogeneous quantum-cascade active *** a strong external RF drive,actively mode-locked pulses as short as 4.4 ps can be produced,as measured by *** demonstrate as well passive waveguides with low insertion loss,enabling the tuning of the laser cavity boundary conditions and the cointegration of active and passive elements on the same THz photonic chip.

关键词： waveguide passive tuning

Post-synthesis phase and shape evolution of CsPbBr3 colloidal nanocrystals: The role of ligands

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Nano Research 2019年第5期12卷 1155-1166页

作者： Elisabetta Fanizza Francesca Cascella Davide Altamura Cinzia Giannini Annamaria Panniello Leonardo Triggiani Francesca Panzarea Nicoletta Depalo Roberto Grisorio Gian Paolo Suranna Angela Agostiano M.Lucia Curri Marinella Striccoli dipartimento di Chimica Università degli Studi di Bari "A.Moro"Via Orabona 470126 BariItaly cnr-istituto per i Processi Chimico Fisici S.S.BariVia Orabona470126 BariItaly cnr-istituto di Cristallografia Via Amendola122/O70126 BariItaly ydipartimento di Ingegneria Civile Ambientaledel TerritorioEdile e di Chimica(DICATECh)Politecnico di BariVia Orabona 470125Italy cnr-NANOTEC-istituto di Nanotecnologia Via Monteroni 73100 LecceItaly

The surface chemistry of colloidal cesium lead bromide (CsPbBr3) nanocrystals is decisive in determining the stability and the final morphology of this class of materials,characterized by ionic structure and a high defect tolerance ***,the high sensitivity of purified colloidal nanocubes of CsPbBr3 to diverse environmental condition (solvent dilution,ageing,ligands post synthetic treatment) in ambient atmosphere is investigated by means of a comprehensive morphological (electron microscopy),structural (θ/2θ X-ray diffraction (XRD) and grazing incidence wide angle scattering (GIWAXS)),and spectroscopic chemical (1H nuclear magnetic resonance (NMR),nuclear Overhauser effect spectroscopy (NOESY),absorption and emission spectroscopy) *** aging and solvent dilution contribute to modify the nanocrystal morphology,due to a modification of the ligand ***,we establish the ability of aliphatic carboxylic acids and aikyl amines ligands to induce,even in a post preparative process at room temperature,structural,morphological and spectroscopic *** post synthesis alkyl amine addition,in particular of oleyl amine and octyl amine,the highly green emitting CsPbBr3 nanocubes effectively tum into one-dimensional (1 D) thin tetragonal nanowires or lead halide deficient rhombohedral zero-dimensional (0D) Cs4PbBr6 structures with a complete loss of *** addition of an alkyl carboxylic acid,as oleic and nonanoic acid,produces the transformation of nanocubes into still emitting orthorombic two-dimensional (2D) *** acid/base equilibrium between the native and added ligands,the edsorbed/free ligands dynamic in solution and the ligand solubility in non-polar solvent contribute to render CsPbBr3 particularly sensitive to environmental and processing conditions and,therefore prone to undergo to structural,morphological and,hence spectroscopic,transformations.

关键词： lead halide perovskite nanocrystals surface chemistry ligands equilibria long term stability

A preliminary simulation study of influence of backsplash on the plastic scintillator detector design in HERD experiment

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Radiation Detection Technology and Methods 2021年第3期5卷 332-338页

作者： Peng Hu Zhi-gang Wang Fabio Gargano Francesca Alemanno Corrado Altomare Tian-wei Bao Yong-wei Dong Valerio Formato dimitrios Kyratzis Nicola Mori Lorenzo Pacini Zheng Quan Davide Serini Jun-jing Wang Rui-jie Wang Ming Xu Bo-bing Wu Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China istituto Nazionale di Fisica Nucleare(infn) Sezione di Bari70126 BariItaly Gran Sasso Science Institute(GSSI) 67100 L’AquilaItaly istituto Nazionale di Fisica Nucleare(infn) Laboratori Nazionali del Gran Sasso67100 L’AquilaItaly dipartimento Interateneo di Fisica dell’Universitàe del Politecnico di Bari 70125 BariItaly istituto Nazionale di Fisica Nucleare(infn) Sezione di Roma Tor Vergata00133 RomeItaly istituto Nazionale di Fisica Nucleare(infn) Sezione di Firenze50019 Sesto FiorentinoItaly

Background The plastic scintillator detector(PSD)is one of the detectors in the high energy cosmic radiation detection(HERD)facility,which is designed for gamma-ray detection and a redundant charge *** will lead to a decrease in PSD’s performance of gamma-ray detection and charge measurement,which should be carefully *** Two preliminary segmentation schemes of the PSD and two veto strategies have been proposed to suppress the backsplash *** this paper,we focus on the influence of the backsplash caused by gamma *** gamma-ray trigger efficiency and identification efficiency were studied in the case of different cell sizes and veto strategies,which can provide guidance on the PSD *** A Monte Carlo simulation based on Geant4 has been *** simplify the simulation,the PSD is segmented into 1 cm3 cubes which can be easily aggregated into cells with different sizes during *** and conclusion Side_Veto can be used as a baseline design of veto strategy,whereas Smart_Veto can be selected as an upgraded *** the PSD bar cell with a width of less than 11 cm and the PSD tile cell with a width of less than 20 cm can achieve a sufficiently high gamma-ray trigger efficiency(>80%),which realizes the primary goal of the ***,both the PSD bar cell with a width of less than 3 cm and the PSD tile cell with a width of less than 20 cm can ensure a sufficiently high gamma-ray identification efficiency(>80%)for photons up to 800 GeV.

关键词： Plastic scintillator detector Gamma-ray detection Backsplash Veto

Marine propellers performance and flow-field prediction by a free-wake panel method

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Journal of Hydrodynamics 2014年第5期26卷 780-795页

作者： GRECO Luca MUSCARI Roberto TESTA Claudio di MASCIO Andrea cnr-INSEAN Italian Ship Model BasinRomeItaly cnr-IAC Istituto per le Applicazioni del Calcolo "M. Picone"RomeItaly

A Boundary Element Method （BEM） hydrodynamics combined with a flow-alignment technique to evaluate blades shed vorticity is presented and applied to a marine propeller in open water. Potentialities and drawbacks of this approach in capturing propeller performance, slipstream velocities, blade pressure distribution and pressure disturbance in the flow-field are highlighted by comparisons with available experiments and RANSE results. In particular, correlations between the shape of the convected vortex- sheet and the accuracy of BEM results are discussed throughout the paper. To this aim, the analysis of propeller thrust and torque is the starting point towards a detailed discussion on the capability of a 3-D free-wake BEM hydrodynamic approach to describe the local features of the flow-field behind the propeller disk, in view of applications to propulsive configurations where the shed wake plays a dominant role.

关键词： BEM hydrodynamics free-wake analysis BEM-RANSE comparison