Intensity (physics)In physics, the intensity or flux of radiant energy is the power transferred per unit area, where the area is measured on the plane perpendicular to the direction of propagation of the energy. In the SI system, it has units watts per square metre (W/m2), or kg⋅s−3 in base units. Intensity is used most frequently with waves such as acoustic waves (sound) or electromagnetic waves such as light or radio waves, in which case the average power transfer over one period of the wave is used.
Microscopie électronique à balayagethumb|right|Premier microscope électronique à balayage par M von Ardenne thumb|right|Microscope électronique à balayage JEOL JSM-6340F thumb|upright=1.5|Principe de fonctionnement du Microscope Électronique à Balayage La microscopie électronique à balayage (MEB) ou scanning electron microscope (SEM) en anglais est une technique de microscopie électronique capable de produire des images en haute résolution de la surface d’un échantillon en utilisant le principe des interactions électrons-matière.
Negative-index metamaterialNegative-index metamaterial or negative-index material (NIM) is a metamaterial whose refractive index for an electromagnetic wave has a negative value over some frequency range. NIMs are constructed of periodic basic parts called unit cells, which are usually significantly smaller than the wavelength of the externally applied electromagnetic radiation. The unit cells of the first experimentally investigated NIMs were constructed from circuit board material, or in other words, wires and dielectrics.
Canis lupus italicusLe Loup d'Italie (Canis lupus italicus), ou Loup des Abruzzes ou encore Loup des Apennins est une sous-espèce de Loups gris originaire d'Italie. Elle a été menacée d’extinction dans le courant du , seule une petite population se maintient maintenant dans le parc national des Abruzzes et en Calabre. Dans les années 1970, grâce à la protection et à l'exode rural qui a permis la reforestation et l'instauration de plans de chasse ainsi que la création d'espaces protégés, le loup a occupé de nouveau l'Apennin du Nord.
Lipid polymorphismPolymorphism in biophysics is the ability of lipids to aggregate in a variety of ways, giving rise to structures of different shapes, known as "phases". This can be in the form of spheres of lipid molecules (micelles), pairs of layers that face one another (lamellar phase, observed in biological systems as a lipid bilayer), a tubular arrangement (hexagonal), or various cubic phases (Fdm, Imm, Iam, Pnm, and Pmm being those discovered so far). More complicated aggregations have also been observed, such as rhombohedral, tetragonal and orthorhombic phases.
3D scanning3D scanner is the process of analyzing a real-world object or environment to collect three dimensional data of its shape and possibly its appearance (e.g. color). The collected data can then be used to construct digital 3D models. A 3D scanner can be based on many different technologies, each with its own limitations, advantages and costs. Many limitations in the kind of objects that can be digitised are still present. For example, optical technology may encounter many difficulties with dark, shiny, reflective or transparent objects.
LycanthropeUn lycanthrope , plus connu en français sous le nom de loup-garou , est, dans les mythologies, les légendes et les folklores principalement issus de la civilisation européenne, un humain qui a la capacité de se transformer, partiellement ou complètement, en loup, ou en créature anthropomorphe proche du loup. Cette transformation peut être due à plusieurs causes, comme une malédiction ou un rituel volontaire, et plus récemment la morsure ou griffure d'un loup ou d'un autre lycanthrope.
Index-matching materialIn optics, an index-matching material is a substance, usually a liquid, cement (adhesive), or gel, which has an index of refraction that closely approximates that of another object (such as a lens, material, fiber-optic, etc.). When two substances with the same index are in contact, light passes from one to the other with neither reflection nor refraction. As such, they are used for various purposes in science, engineering, and art.
Fluid mosaic modelThe fluid mosaic model explains various observations regarding the structure of functional cell membranes. According to this biological model, there is a lipid bilayer (two molecules thick layer consisting primarily of amphipathic phospholipids) in which protein molecules are embedded. The phospholipid bilayer gives fluidity and elasticity to the membrane. Small amounts of carbohydrates are also found in the cell membrane. The biological model, which was devised by Seymour Jonathan Singer and Garth L.
Diffusion des ondesLa diffusion est le phénomène par lequel un rayonnement, comme la lumière, le son ou un faisceau de particules, est dévié dans diverses directions par une interaction avec d'autres objets. La diffusion peut être isotrope, c'est-à-dire répartie uniformément dans toutes les directions, ou anisotrope. En particulier, la fraction de l'onde incidente qui est retournée dans la direction d'où elle provient est appelée rétrodiffusion (backscatter en anglais). La diffusion peut s'effectuer avec ou sans variation de fréquence.