Des agents fédéraux repoussent les badauds près du lieu où Alex Pretti a été abattu par des agents fédéraux qui tentaient de l'arrêter, à Minneapolis, Minnesota, États-Unis, le 24 janvier 2026.
Le monde du doublage en deuil : Michel Barbey, voix française de Bud Spencer et de nombreux personnages de films et dessins animés, est décédé à l’âge de 98 ans.
OTTAWA — Alberta and Ontario are two of Canada's biggest provincial economies, but they're going in opposite directions when it comes to building homes for their residents.Read More
California Post launches Monday as new digital and print newspaper under New York Post Media Group, bringing "plain-spoken journalism" to California's 39 million residents.
Volodymyr Zelensky a de nouveau plaidé, dimanche 25 janvier, en Lituanie pour plus de moyens de défense antiaérienne contre les frappes russes qui ont privé des centaines de milliers d'habitants de Kiev d'électricité et de chauffage au plus fort de l'hiver.
Volodymyr Zelensky a de nouveau plaidé, dimanche 25 janvier, en Lituanie pour plus de moyens de défense antiaérienne contre les frappes russes qui ont privé des centaines de milliers d'habitants de Kiev d'électricité et de chauffage au plus fort de l'hiver.
A new sensor detects helium leaks by monitoring how sound waves propagate through a topological material – no chemical reactions required. Developed by acoustic scientists at Nanjing University, China, the innovative, physics-based device is compact, stable, accurate and capable of operating at very low temperatures.
Helium is employed in a wide range of fields, including aerospace, semiconductor manufacturing and medical applications as well as physics research. Because it is odourless, colourless, and inert, it is essentially invisible to traditional leak-detection equipment such as adsorption-based sensors. Specialist helium detectors are available, but they are bulky, expensive and highly sensitive to operating conditions.
A two-dimensional acoustic topological material
The new device created by Li Fan and colleagues at Nanjing consists of nine cylinders arranged in three sub-triangles with tubes in between the cylinders. The corners of the sub-triangles touch and the tubes allow air to enter the device. The resulting two-dimensional system has a so-called “kagome” structure and is an example of a topological material – that is, one that contains special, topologically protected, states that remain stable even if the bulk structure contains minor imperfections or defects. In this system, the protected states are the corners.
To test their setup, the researchers placed speakers under the corners that send sound waves into the structure and make the gas within it vibrate at a certain frequency (the resonance frequency). When they replaced the air in the device with helium, the sound waves travelled faster, changing the vibration frequency. Measuring this shift in frequency enabled the researchers to calculate the concentration of helium in the device.
Many advantages over traditional gas sensors
Fan explains that the device works because the interface/corner states are impacted by the properties of the gas within it. This mechanism has many advantages over traditional gas sensors. First, it does not rely on chemical reactions, making it ideal for detecting inert gases like helium. Second, the sensor is not affected by external conditions and can therefore work at extremely low temperatures – something that is challenging for conventional sensors that contain sensitive materials. Third, its sensitivity to the presence of helium does not change, meaning it does not need to be recalibrated during operation. Finally, it detects frequency changes quickly and rapidly returns to its baseline once helium levels decrease.
As well as detecting helium, Fan says the device can also pinpoint the direction a gas leak is coming from. This is because when helium begins to fill the device, the corner closest to the source of the gas is impacted first. Each corner thus acts as an independent sensing point, giving the device a spatial sensing capability that most traditional detectors lack.
Other gases could be detected
Detecting helium leaks is important in fields such as semiconductor manufacturing, where the gas is used for cooling, and in medical imaging systems that operate at liquid helium temperatures. “We think our work opens an avenue for inert gas detection using a simple device and is an example of a practical application for two-dimensional acoustic topological materials,” says Fan.
While the new sensor was fabricated to detect helium, the same mechanism could also be employed to detect other gases such as hydrogen, he adds.
Spurred on by these promising preliminary results, which they report in Applied Physics Letters, the researchers plan to extend their fabrication technique to create three-dimensional acoustic topological structures. “These could be used to orientate the corner points so that helium can be detected in 3D space,” says Fan. “Ultimately, we are trying to integrate our system into a portable structure that can be deployed in real-world environments without complex supporting equipment.,” he tells Physics World.
WASHINGTON, D.C. — Andrew Hale, an economist and trade expert based in Washington, D.C., is a citizen of both the United Kingdom and the United States, and a former resident of Canada, where he attended the former Grenville Christian College boarding school as a teen, and later CEGEP and Western University. Hale led a campaign to expose abuses against pupils at Grenville, having experienced them firsthand under the tenure of the headmaster, Rev. Charles R. Farnsworth. Read More
La dernière mise à jour de Samsung s'avère bien problématique. En effet, une faille dans One UI 8 fait que les Galaxy Watch ignorent la fonctionnalité "Ne pas déranger". Les utilisateurs sont donc frustrés par des réveils intempestifs pendant leur sommeil.
Si vous n'avez pas encore craqué pour un nouveau smartphone depuis le début des soldes, cette offre à 479,99 euros chez Carrefour comprenant un Google Pixel 8 et une Nest Cam filaire est franchement alléchante.
Le Conseil de la Paix que Donald Trump vient d’instituer correspond pleinement à sa vision de la diplomatie, qui repose avant tout sur des relations personnelles et des intérêts immédiats, bien plus que
Moins de deux ans après une première restructuration financière, Accell Group pourrait de nouveau devoir renégocier sa dette. Selon plusieurs sources citées par The Financial Times, la situation financière du fabricant européen de vélos reste fragile malgré les mesures déjà engagées.
Déjà leader mondial de la voiture électrique, le géant chinois BYD veut accélérer la cadence. Il prévoit désormais d’exporter pas moins de 1,3 million de véhicules en dehors de son pays natal en 2026.
Le ministère de la fonction publique présentera, mardi 27 janvier, ses premières pistes de travail. Les syndicats dénoncent une réduction des droits en matière de garde d’enfants.
Down break point at 0-2 1-2, Darderi locates an ace, but he must soon handle another, Sinner dashing in to put away a volley having cracked a forehand to the corner. But a netted return restores deuce and from there he closes out the game before celebrating by petulantly throwing down a towel next to his coach. Meantime, Swiatek is doing all she can to prevent Inglis getting on the board, an overhead dispatched with prejudice saving game point at 3-0.
Swiatek breaks Inglis immediately for 2-0 and though, as she seeks to consolidate, she’s taken to deuce, she eventually prevails. She can play a lot better than this – and if she wins, against Rybakina, she’ll have to.
Commons seat campaign by Greater Manchester mayor mid-term would drain resources, says Douglas Alexander
Labour’s decision to bar Andy Burnham from standing in a Westminster byelection was about “focus than about factionalism”, so the party would not be distracted ahead of vital elections in May, Douglas Alexander, the Scotland secretary, has said.
Defending the decision by the party’s national executive committee (NEC) to block the Greater Manchester mayor from being a candidate for the Gorton and Denton byelection, Alexander said this was not because Keir Starmer was scared of a leadership challenge.
Votre boîte de réception Gmail a débordé ce week-end ? Vous n'étiez pas seul face à cette soudaine avalanche de messages promotionnels et d'alertes de spam. Un problème avec les filtres anti-spam et de tri par onglets.
Votre boîte de réception Gmail a débordé ce week-end ? Vous n'étiez pas seul face à cette soudaine avalanche de messages promotionnels et d'alertes de spam. Un problème avec les filtres anti-spam et de tri par onglets.
On pensait avoir épuisé le réservoir de collaborations nostalgiques avec les derniers invités d'Epic Games chez Fortnite, mais l'arrivée de The Office sur l'île vient de prouver le contraire, non sans un certain sens du malaise.
On pensait avoir épuisé le réservoir de collaborations nostalgiques avec les derniers invités d'Epic Games chez Fortnite, mais l'arrivée de The Office sur l'île vient de prouver le contraire, non sans un certain sens du malaise.
Michel Drucker était de retour aux commandes de Vivement dimanche sur France 3 ce 25 janvier 2026. Au cours de l'émission, l'animateur a fait face à une grande première en 60 ans de carrière…
The UK is losing more jobs than it is creating because of artificial intelligence and is being hit harder than rival large economies, new research suggests.
British companies reported that AI had resulted in net job losses over the past 12 months, down 8% – the highest rate among other leading economies including the US, Japan, Germany and Australia, according to a study by the investment bank Morgan Stanley.
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