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Characterization of machine tools and measurement system for micromilling

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Nanotechnology and Precision Engineering 2019年第1期2卷 23-28页

作者： andrea Abeni Matteo Lancini Aldo Attansio Department of Mechanical and Industrial Engineering University of Brescia

Technological progress has led to increased demand for small components with tiny features, which cannot be achieved through conventional machining. Industrial application of processes based on microcutting is limited by some issues concerning the geometrical scale. The process performance is significantly affected by milling machine, tool holder, tool, workpiece material microstructure, workpiece fixtures, and process parameters. At present, an ultimate micromachining assessment procedure is not available. This study aims to propose and conduct an experiment on a testing procedure for micromilling. The set up to be implemented and the output to be considered are defined and described. Three major stages are identified: estimation of the effective bandwidth of the load cell–tool holder system, the milling machine natural frequency measurement, and micromilling test execution. The entire procedure is performed, and its robustness is demonstrated.

关键词： Micromilling Machine tool performance test Tool run-out Force analysis Modal analysis

Female-borne cues affecting Psyttalia concolor （Hymenoptera： Braconidae） male behavior during courtship and mating

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Insect Science 2013年第3期20卷 379-384页

作者： Angelo Canale Giovanni Benelli andrea Lucchi Department of Tree Science Entomology and Plant Pathology University of Pisa Pisa Italy

Knowledge of the mechanisms that regulate courtship and mating behavior in Psyttalia concolor （Sz6pligeti）-a koinobiont endophagous solitary parasitoid of the olive fruit fly, Bactrocera oleae （Rossi）, and of other fruit flies-is essential to its mass rearing and management, Augmentative releases ofP. concolor for olive fruit fly control started in the Mediterranean areas in the 1950s and still continue with limited success. We determined the influence of visual and chemical cues on courtship and mating behavior of this braconid and the possible effect of the mating status of males and females in the perception of these cues. Our results suggest that integration of visual and chemical stimuli are fundamental for mate location and courtship. Indeed, the optimal response of the male was achieved when physical and chemical cues were simultaneously presented and vision and olfaction worked synergistically.

关键词： Bactrocera oleae biological control Ceratitis capitata IPM Opiinae sexual communication

Time-crystal ground state and production of gravitational waves from QCD phase transition

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Chinese Physics C 2019年第6期43卷 115-125页

作者： andrea Addazi Antonino Marcianò Roman Pasechnik Department of Physics &Center for Field Theory and Particle Physics Fudan University Shanghai 200433 China Department of Astronomy and Theoretical Physics Lund University Lund SE-223 62 Sweden

We propose a novel mechanism for the production of gravitational waves in the early Universe that originates from the relaxation processes induced by the QCD phase transition. While the energy density of the quark-gluon mean-field is monotonously decaying in real time, its pressure undergoes a series of violent oscillations at the characteristic QCD time scales that generate a primordial multi-peaked gravitational waves signal in the radio frequencies’ domain. The signal is an echo of the QCD phase transition that is accessible by planned measurements at the FAST and SKA telescopes.

关键词： primordial gravitational waves homogeneous gluon condensate effective Yang-Mills theory QCD phase tran sition

Randomness and Nonlinear Evolution Equations

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Acta Mathematica Sinica,English Series 2019年第6期35卷 903-932页

作者： andrea R.NAHMOD Gigliola STAFFILANI Department of Mathematics University of Massachusetts Amherst Department of Mathematics Massachusetts Institute of Technology

In this paper we survey some results on existence, and when possible also uniqueness, of solutions to certain evolution equations obtained by injecting randomness either on the set of initial data or as a perturbative... 详细信息

关键词： Probabilistic well-posedness Gibbs measure invariance

Coulomb Friction Driving Brownian Motors

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Communications in Theoretical Physics 2014年第10期61卷 505-513页

作者： Alessandro Manacorda andrea Puglisi Alessandro Sarracino Dipartimento di Fisica Università "Sapienza"p.le A.Moro 200185 RomeItaly Istituto dei Sistemi Complessi - CNR and Dipartimento di Fisica Università "Sapienza"p.le A.Moro 200185 RomeItaly Kavli Institute for Theoretical Physics China the Chinese Academy of Sciences Laboratoire de Physique Théorique de la Matière Condensée CNRS UMR 7600case courrier 121Université Paris 64Place Jussieu75255 Paris CedexFrance

We review a family of models recently introduced to describe Brownian motors under the influence of Coulomb friction, or more general non-linear friction laws. It is known that, if the heat bath is modeled as the usual Langevin equation(linear viscosity plus white noise), additional non-linear friction forces are not sufficient to break detailed balance, i.e. cannot produce a motor effect. We discuss two possibile mechanisms to elude this problem. A first possibility, exploited in several models inspired to recent experiments, is to replace the heat bath's white noise by a "collisional noise", that is the effect of random collisions with an external equilibrium gas of particles. A second possibility is enlarging the phase space, e.g. by adding an external potential which couples velocity to position, as in a Klein–Kramers equation. In both cases, non-linear friction becomes sufficient to achieve a non-equilibrium steady state and, in the presence of an even small spatial asymmetry, a motor effect is produced.

关键词： Brownian motors ratchet effect Coulomb friction

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

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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

Visual communication in social play of a hierarchical carnivore species:the case of wild spotted hyenas

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Current Zoology 2022年第4期68卷 411-421页

作者： andrea Paolo Nolfo Grazia Casetta Elisabetta Palagi Department of Biology Unit of EthologyUniversity of PisaVia A.Volta 6Pisa56126Italy Natural History Museum University of PisaVia Roma 79CalciPisa56011Italy

Communication relies on signals that can be produced via different sensory modalities to modify receivers’*** social interactions,the possibility to perceive subtle visual cues enhances the use of facial expressions to exchange *** of the most appropriate fields to explore the specific design features of visual signals is play ***,we explored the production and potential role of Relaxed Open Mouth(ROM)and Head Bobbing(HB)in regulating play fighting of wild spotted hyenas Crocuta crocuta,a highly hierarchical carnivore *** accordance with the assumptions of the signal optimization theory,wild hyenas produced ROM and HB almost exclusively when the sender was in direct visual contact with the receiver thus suggesting that senders were attentive to the playmates’*** to HB,the sequential analysis revealed that ROM often anticipated offensive patterns such as play biting thus supporting the hypothesis that ROM,but not HB,is a metacomunicative ***,when the offensive patterns were biased toward one of the 2 players,the session was punctuated by a higher number of *** findings support the general hypothesis that these 2 visual signals can play different roles in the management of play fighting in this carnivore *** complementary use of ROM and HB would suggest that spotted hyenas are highly competent and fast in processing facial displays of different nature to correctly“read others’intentions”and respond with appropriate motor actions to avoid misunderstanding during one of the most multifaceted and risky social interaction.

关键词： Crocuta crocuta head and facial signals head bobbing metacommunication play fighting relaxed open mouth display

Pettifor maps of complex ternary two-dimensional transition metal sulfides

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npj Computational Materials 2022年第1期8卷 1692-1702页

作者： andrea Silva Jiangming Cao Tomas Polcar Denis Kramer Faculty of Engineering and Physical Sciences University of SouthamptonUniversity RoadSO171BJSouthamptonUK National Centre for Advanced Tribology Study University of SouthamptonSouthamptonUK Faculty of Mechanical and Civil Engineering Helmut-Schmidt-Universität/Universität der Bundeswehr HamburgHolstenhofweg 8522043HamburgGermany Advanced Materials Group Department of Control EngineeringFaculty of Electrical EngineeringCzech Technical University in Prague(CTU)PragueCzech Republic Department of Heterogeneous Catalysis Helmholtz-Zentrum HereonMax-Planck-Strasse 1GeesthachtGermany

Alloying is an established strategy to tune the properties of bulk compounds for desired *** the advent of nanotechnology,the same strategy can be applied to 2D materials for technological applications,like single-layer transistors and solid *** we present a systematic analysis of the phase behaviour of substitutional 2D alloys in the Transition Metal Disulfides(TMD)*** phase behaviour is quantified in terms of a metastability metric and benchmarked against many-body expansion of the energy *** show how the metastability metric can be directly used as starting point for setting up rational search strategies in phase space,thus allowing for targeted further computational prediction and analysis of *** results presented here also constitute a useful guideline for synthesis of TMDs binary alloys via a range of synthesis techniques.

关键词： alloys sulfide behaviour

Dynamical Criticality:Overview and Open Questions

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Journal of Systems Science & Complexity 2018年第3期31卷 647-663页

作者： ROLI andrea VILLANI Marco FILISETTI Alessandro SERRA Roberto Department of Computer Science and Engineering (DISI) Campus of Cesena University of Bologna Italy Department of Physics Informatics and Mathematics University of Modena and Reggio Emilia Italy European Centre for Living Technology Venezia Italy Explora s.r.l. Roma Italy & European Centre for Living Technology Venezia Italy

Systems that exhibit complex behaviours are often found in a particular dynamical con- dition, poised between order and disorder. This observation is at the core of the so-called criticality hypothesis, which states that systems in a dynamical regime between order and disorder attain the highest level of computational capabilities and achieve an optimal trade-off between robustness and flexibility. Recent results in cellular and evolutionary biology, ueuroscience and computer science have revitalised the interest in the criticality hypothesis, emphasising its role as a viable candidate general law in adaptive complex systems. This paper provides an overview of the works on dynamical criticality that are -- To the best of our knowledge -- Particularly relevant for the criticality hypothesis. The authors review the main contributions concerning dynamics and information processing at the edge of chaos, and illustrate the main achievements in the study of critical dynamics in biological systems. Finally, the authors discuss open questions and propose an agenda for future work.

关键词： Attractors criticality dynamical regimes edge of chaos phase transitions.