Comptes Rendus Mecanique最新文献_第4页

Experimental teaching — A tribute to Yves Couder by the example: stroboscopy and fluorescence lifetime with a fan 实验教学-通过示例向伊夫·库德致敬:频闪术和风扇的荧光寿命

IF 0.8 4区工程技术

Comptes Rendus Mecanique Pub Date : 2020-11-16 DOI: 10.5802/crmeca.39

A. Eddi, Paul Baconnier, Matthieu Blons, Samuel Pautrel, S. Protière, E. Fort

{"title":"Experimental teaching — A tribute to Yves Couder by the example: stroboscopy and fluorescence lifetime with a fan","authors":"A. Eddi, Paul Baconnier, Matthieu Blons, Samuel Pautrel, S. Protière, E. Fort","doi":"10.5802/crmeca.39","DOIUrl":"https://doi.org/10.5802/crmeca.39","url":null,"abstract":"Yves Couder created “PhyExp” at Paris Diderot University in 80s. This undergraduate course was meant to introduce experimental physics to students through projects. This approach proved fruitful both for students and teachers and has been replicated Ecole Supérieure de Physique et Chimie Industrielles (ESPCI). As a tribute to Yves, we report here the results obtained during this course about a specific project, namely the measurement of fluorescence lifetimes using stroboscopy and a fan. We obtain quantitative measurements for both Europium and Terbium that are commonly used in fluorescent tubes and we further study the variation of the lifetime with temperature. Résumé. Durant les années 80, Yves Couder a introduit une nouvelle méthode d’enseignement à l’Université Paris Diderot à travers le module “PhyExp”. Au cours de projets expérimentaux, les étudiants découvraient des problèmes originaux de physique ainsi que les méthodes permettant d’y apporter des solutions. Ce module a été reproduit à l’Ecole Supérieure de Physique et Chimie Industrielles (ESPCI) depuis 2014. En forme d’hommage à l’approche d’Yves Couder, nous pésentons ici les résultats obtenus par un groupe d’étudiants dont le projet consistait à mesurer des temps de vie de fluorescence avec des moyens limités (un ventilateur et un spectromètre). En utilisant une méthode stroboscopique, nous avons pu obtenir des mesures quantitatives pour les raies visibles de l’Europium et du Terbium, deux éléments présents dans les tubes fluorescents. Nous avons également évalué la variation de ces temps de vie avec la température.","PeriodicalId":50997,"journal":{"name":"Comptes Rendus Mecanique","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72368111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of neutral modes on the order of a transition 中性模式对跃迁阶的影响

IF 0.8 4区工程技术

Comptes Rendus Mecanique Pub Date : 2020-11-16 DOI: 10.5802/crmeca.21

S. Fauve

引用次数: 0

Tribute to an exemplary man: Yves Couder 向一个模范人物致敬:伊夫·库德

IF 0.8 4区工程技术

Comptes Rendus Mecanique Pub Date : 2020-11-16 DOI: 10.5802/crmeca.35

M. B. Amar, L. Limat, O. Pouliquen, E. Villermaux

引用次数: 0

Terra Bulla, the influence of Yves Couder on the emerging domain of arts and physics sciences Terra Bulla, Yves Couder对新兴艺术和物理科学领域的影响

IF 0.8 4区工程技术

Comptes Rendus Mecanique Pub Date : 2020-11-16 DOI: 10.5802/crmeca.20

J. Chomaz

{"title":"Terra Bulla, the influence of Yves Couder on the emerging domain of arts and physics sciences","authors":"J. Chomaz","doi":"10.5802/crmeca.20","DOIUrl":"https://doi.org/10.5802/crmeca.20","url":null,"abstract":"At the beginning of the eighties Yves Couder started to work in pattern formation field trying to observe and understand structures in complex flows. His approach was different using humble experiments to materialise simple but powerful and elegant ideas. He was establishing with Pierre Gilles De Gennes and Étienne Guyon in particular a novel way of making scientific proof by using demystified “experiences de coin de table” where the simplicity of the setting made the demonstration even more powerful. Science was becoming performative and scientists were in public talks as well as in the lab engaged physically in a tactile way with their experiments. One of Yves first contributions was to use soap films to perform hydrodynamics experiments in two dimensions. The experiments with soap films brought a sense of fragility, emotion and poetry into science; they started and entirely new field of research on bidimensional turbulence using films. This research and novel approach to science opened a pathway for some current domains like table-top sciences, frugal sciences, new types of popularisation like “la main à la pate”, but also the rapidly developing field of arts & sciences. In the present article I will draw on the affiliation of Yves’ works with the arts and sciences using several examples from my own work which is greatly inspired by his approach but also from the work of the fantastic artist duo Evelina Domnitch and Dmitry Gelfand.","PeriodicalId":50997,"journal":{"name":"Comptes Rendus Mecanique","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91045046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Instability of a swirling bubble ring 旋转气泡环的不稳定性

IF 0.8 4区工程技术

Comptes Rendus Mecanique Pub Date : 2020-11-16 DOI: 10.5802/crmeca.22

Yonghui Xu, I. Delbende, D. Fuster, M. Rossi

引用次数: 0

On three-dimensional bluff body wake symmetry breaking with free-stream turbulence and residual asymmetry 三维钝体自由流湍流尾流对称性破缺及残余不对称性

IF 0.8 4区工程技术

Comptes Rendus Mecanique Pub Date : 2020-11-16 DOI: 10.5802/crmeca.32

O. Cadot, Maha Almarzooqi, Antoine Legeai, V. Parezanović, L. Pastur

引用次数: 11

Hydrodynamic quantum field theory: the free particle 流体力学量子场论:自由粒子

IF 0.8 4区工程技术

Comptes Rendus Mecanique Pub Date : 2020-11-16 DOI: 10.5802/crmeca.34

Y. Dagan, J. M. Bush

{"title":"Hydrodynamic quantum field theory: the free particle","authors":"Y. Dagan, J. M. Bush","doi":"10.5802/crmeca.34","DOIUrl":"https://doi.org/10.5802/crmeca.34","url":null,"abstract":"We revisit de Broglie’s double-solution pilot-wave theory in light of insights gained from the hydrodynamic pilot-wave system discovered by Couder and Fort [1]. de Broglie proposed that quantum particles are characterized by an internal oscillation at the Compton frequency, at which rest mass energy is exchanged with field energy. He further proposed that the resulting pilot-wave field satisfies the Klein–Gordon equation. While he developed a guidance equation for the particle, he did not specify how the particle generates the wave. Informed by the hydrodynamic pilot-wave system, we explore a variant of de Broglie’s mechanics in which the form of the Compton-scale dynamic interaction between particle and pilot wave is specified. The particle is modeled as a localized periodic disturbance of the Klein–Gordon field at twice the Compton frequency. We simulate the evolution of the particle position by assuming that the particle is propelled by the local gradient of its pilot wave field. Resonance is achieved between the particle and its pilot wave, leading to self-excited motion of the particle. The particle locks into quasi-steady motion characterized by a mean momentum p̄ =ħk, where k is the wavenumber of the surrounding matter waves. Speed modulations along the particle path arise with the de Broglie wavelength and frequency ck. The emergent dynamics is strongly reminiscent of that arising in the hydrodynamic pilot-wave system, on the basis of which we anticipate the emergence of quantum statistics in various settings. Our results suggest the potential value of a new hydrodynamically-inspired pilot-wave theory for the motion of quantum particles.","PeriodicalId":50997,"journal":{"name":"Comptes Rendus Mecanique","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86022429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Resonant interactions in bouncing droplet chains 弹跳液滴链中的共振相互作用

IF 0.8 4区工程技术

Comptes Rendus Mecanique Pub Date : 2020-11-16 DOI: 10.5802/crmeca.30

Lauren Barnes, G. Pucci, Anand U. Oza

{"title":"Resonant interactions in bouncing droplet chains","authors":"Lauren Barnes, G. Pucci, Anand U. Oza","doi":"10.5802/crmeca.30","DOIUrl":"https://doi.org/10.5802/crmeca.30","url":null,"abstract":"In a pioneering series of experiments, Yves Couder, Emmanuel Fort and coworkers demonstrated that droplets bouncing on the surface of a vertically vibrating fluid bath exhibit phenomena reminiscent of those observed in the microscopic quantum realm. Inspired by this discovery, we here conduct a theoretical and numerical investigation into the structure and dynamics of one-dimensional chains of bouncing droplets. We demonstrate that such chains undergo an oscillatory instability as the system’s wave-induced memory is increased progressively. The predicted oscillation frequency compares well with previously reported experimental data. We then investigate the resonant oscillations excited in the chain when the drop at one end is subjected to periodic forcing in the horizontal direction. At relatively high memory, the drops may oscillate with an amplitude larger than that prescribed, suggesting that the drops eVectively extract energy from the collective wave field. We also find that dynamic stabilization of new bouncing states can be achieved by forcing the chain at high frequency. Generally, our work provides insight into the collective behavior of particles interacting through long-range and temporally nonlocal forces.","PeriodicalId":50997,"journal":{"name":"Comptes Rendus Mecanique","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86068053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Yves Couder (1941–2019): A life in search of the beauty of fluid motion 伊夫·库德(1941-2019):一生都在寻找流体运动之美

IF 0.8 4区工程技术

Comptes Rendus Mecanique Pub Date : 2020-11-16 DOI: 10.5802/crmeca.37

P. Huerre

引用次数: 0

A secure version of asymptotic numerical method via convergence acceleration 基于收敛加速的渐近数值方法的一个安全版本

IF 0.8 4区工程技术

Comptes Rendus Mecanique Pub Date : 2020-11-10 DOI: 10.5802/crmeca.48

P. Ventura, M. Potier-Ferry, H. Zahrouni

{"title":"A secure version of asymptotic numerical method via convergence acceleration","authors":"P. Ventura, M. Potier-Ferry, H. Zahrouni","doi":"10.5802/crmeca.48","DOIUrl":"https://doi.org/10.5802/crmeca.48","url":null,"abstract":"The paper deals with the numerical computation of difficult problems requiring many steps and many degrees of freedom such as the finite element analysis of wrinkling of film–substrate systems. The asymptotic numerical method (ANM) is well adapted to such computations but with a progressive loss of accuracy during step chaining. Thus, correction phases are necessary, which are rarely carried out within ANM. A convergence acceleration algorithm and a step-length adaptation have been included to limit the growth of computation time and to strengthen the reliability of the procedure. This modified version of the ANM is assessed by simulating the appearance and evolution of sinusoidal wrinkles under uniaxial compression. Résumé. L’article étudie le calcul numérique de problèmes difficiles nécessitant de nombreux pas et un grand nombre de degrés de liberté, comme l’étude par éléments finis du plissement de systèmes film– substrat. La méthode asymptotique numérique (ANM) est bien adaptée à de tels calculs, mais avec une lente perte de précision lors de l’enchainement de nombreux pas de calculs. Donc des étapes de correction sont indispensables, ce qui est rarement fait lors de calculs par ANM. L’algorithme de cheminement est complété par une méthode d’accélération de convergence et par une technique d’adaptation de la longueur de pas pour minimiser le temps de calcul et pour fiabiliser la procédure. Cette version modifiée de la méthode asymptotique numérique a été évaluée par la simulation de l’apparition de plis sinusoïdaux en compression","PeriodicalId":50997,"journal":{"name":"Comptes Rendus Mecanique","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2020-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84393555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1