Lead–lag compensatorA lead–lag compensator is a component in a control system that improves an undesirable frequency response in a feedback and control system. It is a fundamental building block in classical control theory. Lead–lag compensators influence disciplines as varied as robotics, satellite control, automobile diagnostics, LCDs and laser frequency stabilisation. They are an important building block in analog control systems, and can also be used in digital control. Given the control plant, desired specifications can be achieved using compensators.
Serveur webvignette|Serveurs de la Wikimedia Foundation. Un serveur web est soit un logiciel de service de ressources web (serveur HTTP), soit un serveur informatique (ordinateur) qui répond à des requêtes du World Wide Web sur un réseau public (Internet) ou privé (intranet), en utilisant principalement le protocole HTTP. Un serveur informatique peut être utilisé à la fois pour servir des ressources du Web et pour faire fonctionner en parallèle d'autres services liés, comme l'envoi de courriers électroniques, l'émission de flux en streaming, le stockage de données dans des bases de données, le transfert de fichiers par .
Superfluid helium-4Superfluid helium-4 is the superfluid form of helium-4, an isotope of the element helium. A superfluid is a state of matter in which matter behaves like a fluid with zero viscosity. The substance, which looks like a normal liquid, flows without friction past any surface, which allows it to continue to circulate over obstructions and through pores in containers which hold it, subject only to its own inertia. The formation of the superfluid is known to be related to the formation of a Bose–Einstein condensate.
Macroscopic quantum phenomenaMacroscopic quantum phenomena are processes showing quantum behavior at the macroscopic scale, rather than at the atomic scale where quantum effects are prevalent. The best-known examples of macroscopic quantum phenomena are superfluidity and superconductivity; other examples include the quantum Hall effect and topological order. Since 2000 there has been extensive experimental work on quantum gases, particularly Bose–Einstein condensates. Between 1996 and 2016 six Nobel Prizes were given for work related to macroscopic quantum phenomena.
