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Topological optimization of ballistic protective structures through genetic algorithms in a vulnerability-driven environment

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Defence Technology（防务技术） 2024年第10期40卷 125-137页

作者： Salvatore Annunziata Luca Lomazzi Marco Giglio andrea Manes Politecnico di Milano Department of Mechanical EngineeringVia Giuseppe La Masa120156Italy

Reducing the vulnerability of a platform,i.e.,the risk of being affected by hostile objects,is of paramount importance in the design process of vehicles,especially aircraft.A simple and effective way to decrease vulnerability is to introduce protective structures to intercept and possibly stop ***,this type of solution can lead to a significant increase in weight,affecting the performance of the *** this reason,it is crucial to study possible solutions that allow reducing the vulnerability of the aircraft while containing the increase in structural *** possible strategy is to optimize the topology of protective solutions to find the optimal balance between vulnerability and the weight of the added *** the many optimization techniques available in the literature for this purpose,multiobjective genetic algorithms stand out as promising *** this context,this work proposes the use of a in-house software for vulnerability calculation to guide the process of topology optimization through multi-objective genetic algorithms,aiming to simultaneously minimize the weight of protective structures and *** addition to the use of the in-house software,which itself represents a novelty in the field of topology optimization of structures,the method incorporates a custom mutation function within the genetic algorithm,specifically developed using a graph-based approach to ensure the continuity of the generated *** tool developed for this work is capable of generating protections with optimized layouts considering two different types of impacting objects,namely bullets and fragments from detonating *** software outputs a set of non-dominated solutions describing different topologies that the user can choose from.

关键词： Topological optimization Protective structure Genetic algorithm Survivability Vulnerability

Numerical study on fatigue crack propagation behaviors in lubricated rolling contact

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Chinese Journal of Aeronautics 2021年第9期34卷 24-36页

作者： Haifeng HE Huaiju LIU Caichao ZHU andrea MURA State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China Department of Mechanical and Aerospace Engineering Politecnico di TorinoTorino 10129Italy

The surface-initiated Rolling Contact Fatigue(RCF)including pitting and micro-pitting is one of the key issues affecting the reliability of tribological components such as gears and bearings used in various *** this work,a surface-initiated crack Finite Element(FE)model which considers the effect of lubricant on crack faces was developed to investigate surface-initiated RCF using an automatic crack propagating Python *** lubricating states,initial crack parameters and loading conditions were simulated to analyze the evolution of crack propagation and the Stress Intensity Factors(SIFs).The RCF crack propagation path and life were predicted by employing the Maximum Tangential Stress(MTS)criterion coupled with the Paris’s law.A typical RCF failure is predicted in the numerical *** reveal that the lubricating pressurization dominates the surface-initiated *** addition,the initial crack angle has a significant effect on the RCF crack propagation path and the fatigue life.

关键词： Fatigue crack propagation Finite element Life prediction Lubricating states Rolling Contact Fatigue(RCF) Stress Intensity Factors(SIFs)

Simple experimental procedures to distinguish photothermal from hot-carrier processes in plasmonics

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Light(Science & Applications) 2020年第1期9卷 974-989页

作者： Guillaume Baffou Ivan Bordacchini andrea Baldi Romain Quidant Institut Fresnel CNRSAix Marseille UniversityCentrale MarseilleMarseilleFrance ICFO-Institut de Ciencies Fotoniques The Barcelona Institute of Science and Technology08860CastelldefelsBarcelonaSpain DIFFER-Dutch Institute for Fundamental Energy Research De Zaale 205612 AJ EindhovenThe Netherlands Vrije Universiteit Amsterdam De Boelelaan 10811081 HV AmsterdamThe Netherlands ICREA-Institucio Catalana de Recerca i Estudis Avancats 08010 BarcelonaSpain Nanophotonic Systems Laboratory Department of Mechanical and Process EngineeringETH Zurich8092ZurichSwitzerland

Light absorption and scattering of plasmonic metal nanoparticles can lead to non-equilibrium charge carriers,intense electromagnetic near-fields,and heat generation,with promising applications in a vast range of fields,from chemical and physical sensing to nanomedicine and photocatalysis for the sustainable production of fuels and *** the relative contribution of thermal and non-thermal contributions in plasmon-driven processes is,however,*** temperature measurements are technically challenging,and macroscale experiments are often characterized by collective heating effects,which tend to make the actual temperature increase *** work is intended to help the reader experimentally detect and quantify photothermal effects in plasmon-driven chemical reactions,to discriminate their contribution from that due to photochemical processes and to cast a critical eye on the current *** this aim,we review,and in some cases propose,seven simple experimental procedures that do not require the use of complex or expensive thermal microscopy *** proposed procedures are adaptable to a wide range of experiments and fields of research where photothermal effects need to be assessed,such as plasmonic-assisted chemistry,heterogeneous catalysis,photovoltaics,biosensing,and enhanced molecular spectroscopy.

关键词： collective photochemical intense

Galectin-3 prospects as a therapeutic agent for multiple sclerosis

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Neural Regeneration Research 2019年第8期14卷 1380-1382页

作者： Laura Thomas Laura andrea Pasquini Department of Biological Chemistry School of Pharmacy and Biochemistry Institute of Chemistry Biological Physicochemistry (IQUIFIB) University of Buenos Aires and National Research Council (CONICET)

Galectin-3 (Gal-3) in oligodendrocyte (OLG) differentiation: OLGs are the cells in charge of myelination in the central nervous system (CNS), allowing rapid conduction of the neural action potential and giving trophic support to axons. OLGs undergo a series of changes throughout their life cycle: first, upon neural stem cell comm让ment to the OLG lineage, cells referred to as OLG precursor cells (OPC) present a bipolar morphology, have proliferative and migratory capacity and express molecular markers like platelet-derived growth factor receptor alpha and neural/glial antigen 2.

关键词： multiple sclerosis therapeutic agent Galectin-3 prospects

Proteomic Analysis of the Proplastid Envelope Membrane Provides Novel Insights into Small Molecule and Protein Transport across Proplastid Membranes

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Molecular Plant 2009年第6期2卷 1247-1261页

作者： andrea Brautigam andreas RM. Weber Institut fur Biochemie der Pflanzen Heinrich Heine Universitat Universitatsstrasse 1 D-40225 Dusseldorf Germany Genetics Program Michigan State University East Lansing MI USA Department of Plant Biology Michigan State University East Lansing MI USA

Proplastids are undifferentiated plastids of meristematic tissues that synthesize amino acids for protein synthesis, fatty acids for membrane lipid production, and purines and pyrimidines for DNA and RNA synthesis. Unlike chloroplasts, proplastids depend on supply, with reducing power, energy, and precursor metabolites from the remainder of the cell. Comparing proplastid and chloroplast envelope proteomes and the corresponding transcriptomes of leaves and shoot apex revealed a clearly distinct composition of the proplastid envelope. It is geared towards import of metabolic precursors and export of product metabolites for the rapidly dividing cell. The analysis also suggested a new role for the triosephosphate translocator in meristematic tissues, identified the route of organic nitrogen import into proplastids, and detected an adenine nucleotide exporter. The protein import complex contains the import receptors Toc120 and Toc132 and lacks the redox sensing complex subunits of Tic32, Tic55, and Tic62, which mirrors the expression patterns of the corresponding genes in leaves and the shoot apex. We further show that the protein composition of the internal membrane system is similar to etioplasts, as it is dominated by the ATP synthase complex and thus remarkably differs from that of chloroplast thylakoids.

关键词： Membrane biochemistry proteomics transporters chloroplast biology membrane proteins transcriptome analysis.

Gravitational wave astronomy

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Frontiers of physics 2013年第6期8卷 771-793页

作者： Gabriela Gonzalez andrea Vicere Linqing Wen Department of Physics and Astronomy Louisiana State University Baton Rouge LA 70803 USA INFN Sezione di Firenze 1-50019 Sesto Fiorentino and Universitd degli Studi di Urbino 'Carlo Bo' 1-61029 Urbino Italy School of Physics The University of Western Australia 35 Stirling Hwy Crawley WA 6009 Australia

We are entering a new era of gravitational-wave astronomy. The ground-based interferometers have reached their initial design sensitivity in the audio band. Several upper limits have been set for anticipated astrophysical sources from the science data. The advanced detectors in the US and in Europe are expected to be operational around 2015. New advanced detectors are also planned in Japan and in India. The first direct detections of gravitational waves are expected within this decade. In the meanwhile, three pulsar timing array projects are forming an international collaboration to detect gravitational waves directly in the nanoHertz range using timing data from millisecond pulsars. The first direct detection of nanoHertz gravitational waves are also expected within this decade. In this paper, we review the status of current gravitational-wave detectors, possible types of sources, observational upper limits achieved, and future prospects for direct detection of gravitational waves

关键词： gravitational waves gravitational-wave detectors gravitional astronomy

Experimental characterization of the 3D linear viscoelastic behavior of cold recycled bitumen emulsion mixtures

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Journal of Traffic and Transportation Engineering(English Edition) 2019年第4期6卷 324-336页

作者： andrea Graziani Carlotta Godenzoni Francesco Canestrari Dipartimento di Ingegneria Civile Edile e Architettura Università Politecnica delle Marche

Cold mixtures with bitumen emulsion are produced at ambient temperature, leading to substantial reductions of energy consumption and atmospheric emissions. In cold recycling applications, cement is normally used to improve the mixture performance. Thus, the rheological behavior of cold recycled mixtures is different from that of conventional hot mixtures because it is due to the interaction of fresh bitumen, aged bitumen and cementitious bonds. In this study, we investigated the three-dimensional(3 D) linear viscoelastic(LVE) behavior of a cement-bitumen treated material(CBTM) mixture fabricated using bitumen emulsion and cement. For comparison, we also investigated the 3 D LVE behavior of hot-mix asphalt containing 25% of reclaimed asphalt and fabricated using polymermodified binder. Sinusoidal axial tests on cylindrical specimens, were carried out at various temperatures(from 0℃ to 50℃) and frequencies(from 0.1 to 12 Hz). The complex Young’s modulus E~*and the complex Poisson’s ratio v~*were determined through the measurement of axial and transverse strain. We show that when considering E*, CBTM mixtures may be considered thermo-rheologically simple and the Huet-Sayegh model can be used to simulate the frequencyetemperature dependence. On the other hand, when considering v*the behavior of CBTM mixtures is very different from that of hot mix asphalt. In particular, its absolute value is almost constant and very close to 0.15.

关键词： Bitumen emulsion Cold recycling Complex modulus Complex Poisson’s ratio Huet-Sayegh model

The Behavior of Solutions of Multidimensional Aggregation Equations with Mildly Singular Interaction Kernels

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Chinese Annals of Mathematics,Series B 2009年第5期30卷 463-482页

作者： andrea L.BERTOZZI Thomas LAURENT Department of Mathematics University of California-Los AngelesLos Angeles

The authors consider the multidimensional aggregation equation tp-div（p K＊ ρ） = 0 in which the radially symmetric attractive interaction kernel has a mild singularity at the origin （Lipschitz or better）, and review recent results on this problem concerning well-posedness of nonnegative solutions and finite time blowup in multiple space dimensions depending on the behavior of the kernel at the origin. The problem with bounded initial data, data in L^p ∩ L^1, and measure solutions are also considered.

关键词： Well-posedness Blowup Osgood condition

The role of the serum testosterone levels as a predictor of prostate cancer in patients with atypical small acinar proliferation at the first prostate biopsy

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Asian Journal of Andrology 2018年第1期20卷 15-18页

作者： Lucio DelrAtti andrea B Galosi Department of Urology University Hospital St. Anna Ferrara 44124 Italy Department of Urology Polytechnic University of Marche Ancona 60126 Italy

The current literature does not support the usefulness of clinical markers on predicting which patients with atypical small acinar proliferation （ASAP） are more likely to progress to prostate cancer （PCa）. Androgens have long been considered to be the potential risk factors for PCa. However, the role of testosterone is controversial. The present study aims to analyze the relationship between serum testosterone （TS） levels and the diagnosis of PCa after a first prostate biopsy in patients affected by ASAP. This retrospective study included 143 patients diagnosed with ASAP in an initial transrectal ultrasound-guided prostate biopsy for suspicious PCa according to the European Association of Urology guidelines. Their TS levels, age, PSA, prostate volume, digital rectal examination, and prostate biopsy Gleason score （GS） were collected retrospectively for statistical analysis. All patients included in the study had a second biopsy and were suitable for further analysis. Re-biopsy was carried out 3-6 months after the first diagnosis of ASAP. Low and normal TS groups were composed of 29 （20.3%） and 114 （79.7%） patients, respectively. The diagnosis of the second biopsy was ASAP in 25.2% and PCa in 36.4% of patients. The comparison between patients with PCa and those with negative or an ASAP result in the second biopsy reported that men with cancer had significantly higher levels of TS （P 〈 0.001）. However, there was no statistically significant association between GS postbiopsy and TS （P = 0.324）. Our experience demonstrated that eugonadal patients may be a clinical risk factor for the diagnosis of PCa on re-biopsy after ASAP diagnosis than hypogonadal.

关键词： atypical small acinar proliferation prostate biopsy prostate cancer testosterone