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Do different kinds of photon-pair sources have the same indistinguishability in quantum silicon photonics?

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Photonics Research 2023年第11期11卷 1820-1837页

作者： JONG-MOO LEE ALESSIO BALDAZZI MATTEO SANNA STEFANO AZZINI JOON TAE AHN MYUNG-LAE LEE YOUNGIK SOHN LORENZO PAVESI Electronics and Telecommunications Research Institute(ETRI) Daejeon 34129Republic of Korea department of Physics University of Trento38123 TrentoItaly Korea Advanced Institute of Science and Technology(KAIST) Daejeon 34141Republic of Korea

In the same silicon photonic integrated circuit,we compare two types of integrated degenerate photon-pair sources(microring resonators and waveguides)using Hong–Ou–Mandel(HOM)interference *** nominally identical microring resonators are coupled to two nominally identical waveguides,which form the arms of a Mach–Zehnder *** is pumped by two lasers at two different wavelengths to generate,by spontaneous four-wave mixing,degenerate photon *** particular,the microring resonators can be thermally tuned in or out of resonance with the pump wavelengths,thus choosing either the microring resonators or the waveguides as photon-pair sources,*** this way,an on-chip HOM visibility of 94%with microring resonators and 99%with straight waveguides is measured upon *** compare our experimental results with theoretical simulations of the joint spectral intensity and the purity of the degenerate photon *** verify that the visibility is connected to the sources’indistinguishability,which can be quantified by the overlap between the joint spectral amplitudes(JSA)of the photon pairs generated by the two *** estimate a JSA overlap of 98%with waveguides and 89%with microring resonators.

关键词： interferometer pumped pump

Ultrathin Wood Laminae–Thermoplastic Starch Biodegradable Composites

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Journal of Renewable Materials 2018年第5期6卷 493-503页

作者： Andrea Dorigato Martino Negri Alessandro Pegoretti university of trento Department of Industrial Engineering and INSTM Research UnitVia Sommarive 938123 TrentoItaly Trees&Timber Institute CNR IVALSAI-38010 San Michele all’AdigeTrentoItaly

Novel fully biodegradable thermoplastic composite laminates reinforced with ultrathin wood laminae were prepared through a hot-pressing process by using two different thermoplastic starch(TPS)*** microstructure and physical properties of the resulting unidirectional and bidirectional laminates were *** investigated materials presented a complex microstructure,in which the porosity of the wood laminae was almost entirely occluded by the polymer *** mechanical behavior of the laminates was strongly affected by the obtained microstructure,and matrix penetration in wood pores led to biodegradable composites with elastic modulus and tensile strength higher than those of their ***,thermal welding and thermoformability tests proved how these materials possess features typical of thermoplastic materials.

关键词： Starch ultrathin wood laminae composites mechanical properties

A Finite Volume Upwind-Biased Centred Scheme for Hyperbolic Systems of Conservation Laws:Application to Shallow Water Equations

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Communications in Computational Physics 2012年第9期12卷 1183-1214页

作者： Guglielmo Stecca Annunziato Siviglia Eleuterio F.Toro department of Civil and Environmental Engineering University of TrentoVia Mesiano 77I-38100 TrentoItaly Laboratory of AppliedMathematics University of TrentoVia Mesiano 77I-38100 TrentoItaly.

We construct a new first-order central-upwind numerical method for solving systems of hyperbolic equations in conservative *** applies in multidimensional structured and unstructured *** proposed method is an extension of the UFORCEmethod developed by Stecca,Siviglia and Toro[25],in which the upwind bias for the modification of the staggered mesh is evaluated taking into account the smallest and largest wave of the entire Riemann *** proposed first-order method is shown to be identical to the Godunov upwindmethod in applications to a 2×2 linear hyperbolic *** method is then extended to non-linear systems and its performance is assessed by solving the two-dimensional inviscid shallow water *** to second-order accuracy is carried out using an ADER-WENO approach in the finite volume framework on unstructured ***,numerical comparison with current competing numerical methods enables us to identify the salient features of the proposed method.

关键词： Conservative hyperbolic systems centred schemes unstructured meshes numerical fluxes shallow water equations FORCE upwind-biased

Applying an ecosystem services approach to support land-use planning:a case study in Koboko district,Uganda

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Ecological Processes 2014年第1期3卷 159-171页

作者： Lighea Speziale Davide Geneletti department of Civil Environmental and Mechanical EngineeringUniversity of TrentoVia Mesiano 7738123 TrentoItaly UNESCO Chair in Engineering for Human and Sustainable Development University of TrentoVia Mesiano 7738123 TrentoItaly

Introduction:This paper presents a case study of the application of an ecosystem services framework to support land-use *** district of Koboko,in northwestern Uganda,formed the study *** overall purpose was to improve the understanding of links between human actions,their impact on ecosystems and the services they provide,and,ultimately,consequences for human *** framework developed by the Millennium Ecosystem Assessment was used as a main conceptual *** analysis comprised four main stages:(1)identification of the main ecosystems and their services;(2)analysis of human wellbeing components,focusing on poverty issues;(3)assessment of the interrelations between ecosystem services and human wellbeing;(4)identification of the main drivers of change and development of future spatial development ***:The scenarios were developed starting from the main drivers of change and show the dependency of human wellbeing on ecosystems services,identifying how spatial development strategies can affect that *** information was not easily available,therefore scenario development made use of both quantitative and qualitative *** results of qualitative and quantitative approaches were consistent,proving the strength and flexibility of the ***:Scenario results aim to provide guidance for local government land-use planning,focusing on the promotion of sustainability through ecosystem services *** spatially explicit analysis illustrated how different policies affect urban development;it was clearly shown that even with very different demographic outcomes,the impact of sectorial policies guaranteed a good level of suitability for new residential areas.

关键词： qualitative starting consequences

A Novel Staggered Semi-implicit Space-Time Discontinuous Galerkin Method for the Incompressible Navier-Stokes Equations

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Communications on Applied Mathematics and Computation 2021年第4期3卷 607-647页

作者： F.L.Romeo M.Dumbser M.Tavelli department of Civil Environmental and Mechanical EngineeringUniversity of TrentoVia Mesiano 7738123 TrentoItaly

A new high-order accurate staggered semi-implicit space-time discontinuous Galerkin(DG)method is presented for the simulation of viscous incompressible flows on unstructured triangular grids in two space *** staggered DG scheme defines the discrete pressure on the primal triangular mesh,while the discrete velocity is defined on a staggered edge-based dual quadrilateral *** this paper,a new pair of equal-order-interpolation velocity-pressure finite elements is *** the primary triangular mesh(the pressure elements),the basis functions are piecewise polynomials of degree N and are allowed to jump on the boundaries of each *** the dual mesh instead(the velocity elements),the basis functions consist in the union of piecewise polynomials of degree N on the two subtriangles that compose each quadrilateral and are allowed to jump only on the dual element boundaries,while they are continuous *** other words,the basis functions on the dual mesh arc built by continuous finite elements on the *** choice allows the construction of an efficient,quadrature-free and memory saving *** our coupled space-time pressure correction formulation for the incompressible Navier-Stokes equations,the arbitrary high order of accuracy in time is achieved through tire use of time-dependent test and basis functions,in combination with simple and efficient Picard *** numerical tests on classical benchmarks confirm that the proposed method outperforms existing staggered semi-implicit space-time DG schemes,not only from a computer memory point of view,but also concerning the computational time.

关键词： Incompressible Navier-Stokes equations Semi-implicit space-time discontinuous Galerkin schemes Staggered unstructured meshes Space-time pressure correction method High-order accuracy in space and time

Curl Constraint-Preserving Reconstruction and the Guidance it Gives for Mimetic Scheme Design

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Communications on Applied Mathematics and Computation 2023年第1期5卷 235-294页

作者： Dinshaw S.Balsara Roger Käppeli Walter Boscheri Michael Dumbser Physics and ACMS departments University of Notre DameNotre DameINUSA Seminar for Applied Mathematics(SAM) Department of MathematicsETH ZürichCH-8092 ZurichSwitzerland department of Mathematics and Computer Science University of FerraraFerraraItaly Laboratory of Applied Mathematics Department of CivilEnvironmental and Mechanical EngineeringUniversity of TrentoTrentoItaly

Several important PDE systems,like magnetohydrodynamics and computational electrodynamics,are known to support involutions where the divergence of a vector field evolves in divergence-free or divergence constraint-preserving ***,new classes of PDE systems have emerged for hyperelasticity,compressible multiphase flows,so-called firstorder reductions of the Einstein field equations,or a novel first-order hyperbolic reformulation of Schrödinger’s equation,to name a few,where the involution in the PDE supports curl-free or curl constraint-preserving evolution of a vector *** study the problem of curl constraint-preserving reconstruction as it pertains to the design of mimetic finite volume(FV)WENO-like schemes for PDEs that support a curl-preserving involution.(Some insights into discontinuous Galerkin(DG)schemes are also drawn,though that is not the prime focus of this paper.)This is done for two-and three-dimensional structured mesh problems where we deliver closed form expressions for the *** importance of multidimensional Riemann solvers in facilitating the design of such schemes is also *** two dimensions,a von Neumann analysis of structure-preserving WENOlike schemes that mimetically satisfy the curl constraints,is also *** shows the tremendous value of higher order WENO-like schemes in minimizing dissipation and dispersion for this class of *** results are also presented to show that the edge-centered curl-preserving(ECCP)schemes meet their design *** paper is the first paper that invents non-linearly hybridized curl-preserving reconstruction and integrates it with higher order Godunov *** its very design,this paper is,therefore,intended to be forward-looking and to set the stage for future work on curl involution-constrained PDEs.

关键词： PDEs Numerical schemes Mimetic

Ordering and disordering of in situ grown MgAl-layered double hydroxide and its effect on the structural and corrosion resistance properties

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International Journal of Minerals,Metallurgy and Materials 2019年第12期26卷 1570-1577页

作者： Muhammad Ahsan Iqbal Michele Fedel department of Industrial Engineering University of Trento

A MgAl-layered double hydroxide(MgAl-LDH)protective film was developed on AA6082 substrates via the in situ hydrothermal growth method to obtain a distinct cauliflower-like LDH structure,and coated substrates were further heat-treated in air at temperatures from 100 to 250℃ to further improve the corrosion resistance of MgAl-LDH by taking advantage of the LDH memory effect;also,the effect of calcination on MgAl-LDH structural stability and the corresponding corrosion resistance properties were *** structural characterization of uncalcined and calcined LDH films were examined using scanning electron microscopy,energy-dispersive spectroscopy,X-ray diffraction,thermogravimetric analysis,differential scanning calorimetry,and Fourier transform infrared *** corresponding corrosion protection efficiency of the developed coating was studied through potentiodynamic polarization experiments and by electrochemical impedance *** with uncalcined MgAl-LDH,the calcined film showed a relatively lower corrosion current density and a higher impedance value,especially after heat treatment at 250℃.The findings demonstrate that calcination strongly affects the oriented growth of the LDH and causes an increase in the surface area and contraction of the basal spacing,which in turn caused a compact structure that substantially influenced the LDH corrosion resistance properties.

关键词： layered double hydroxide calcination in situ growth thin films corrosion protection

σ-Phase in Lean Duplex Stainless Steel Sheets

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Acta Metallurgica Sinica(English Letters) 2015年第3期28卷 331-337页

作者： Marco Breda Massimo Pellizzari Marco Frigo Industrial Engineering department(DII) University of PadovaVia Marzolo 9Int.435131 PaduaItaly Industrial Engineering department(DII) University of TrentoVia Mesiano 7738123 TrentoItaly Outokumpu S.p.A. Piazza Piccapietra 916121 GenoaItaly

The precipitation kinetics of secondary phases in two austeno-ferritic lean duplex stainless steels（lean DSS）were examined after aging the materials at 800 ℃.Owing to the instability of ferrite,all DSS are known to be sensitive to solid-state phase transformations in the critical temperature range 600-1,000 ℃ and different secondary phases may form,depending on composition and *** performed thermodynamic simulations revealed the proneness to the precipitation of such phases also have been done in lean DSS,but only information on the equilibrium microstructures were ***,the materials were aged at various times,in order to verify the simulations and determine the precipitation *** occurred structural modifications were observed and quantified by scanning electron microscope and X-ray diffraction measurements,determining phase type,composition and volumetric *** 800 ℃,grade 2101 was found to be only affected by Cr_2N nitrides precipitation,whereas a significant amount of σ-phase was found to form in LDX 2404 for treatment longer than 1 h,almost totally replacing ferrite after 50 *** to now,the intermetallic σ-phase has been observed only in the high alloyed DSS,and the unexpected precipitation in grade 2404 highlighted that the increased content of molybdenum in this steel might be considered as determinant for the formation.

关键词： Lean duplex stainless steels Isothermal heat treatments σ-Phase Chromium nitrides Precipitation kinetics

Silicon nanocrystals to enable silicon photonics

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Chinese Optics Letters 2009年第4期7卷 319-324页

作者： Lorenzo Pavesi Nanoscience Laboratory Department of PhysicsUniversity of Trento

Low dimensional silicon, where quantum size effects play significant roles, enables silicon with new photonic functionalities. In this short review, we discuss the way that silicon nanocrystals are produced, their optoelectronic properties and a few device applications. We demonstrate that low dimensional silicon is an optimum material for developing silicon photonics.

关键词： Nanocrystals Photonic devices