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Gurzhi Effect
The Gurzhi effect was theoretically predicted by Radii Gurzhi in 1963, and it consists of decreasing of electric resistance R of a finite size conductor with increasing of its temperature T (i.e. the situation dR/dT < 0 for some temperature interval). Gurzhi effect usually being considered as the evidence of electron transport in conducting media. The mechanism of Gurzhi effect is the following. The value of the resistance of the conductor is inverse to the — a mean free path corresponding to the momentum loss from the s+s systemwhere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gurzhi Effect
The Gurzhi effect was theoretically predicted by Radii Gurzhi in 1963, and it consists of decreasing of electric resistance R of a finite size conductor with increasing of its temperature T (i.e. the situation dR/dT < 0 for some temperature interval). Gurzhi effect usually being considered as the evidence of electron transport in conducting media. The mechanism of Gurzhi effect is the following. The value of the resistance of the conductor is inverse to the — a mean free path corresponding to the momentum loss from the s+s systemwhere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wires Gurzhi Effect
A wire is a strand of drawn metal used especially in electrical conductors and fencing. wire may also refer to: Abbreviations Note: These terms are often shortened to simply ''wire'', ''wires'' or ''wired''. * Wire, a covert listening device worn as a wire under a person's clothes * Wire, an informal term for a telegraph, or the act of using a telegraph * Wire service, a journalism-jargon term for news agency (a news''wire'' or ''wire'' service) * Wire tap, police jargon for covert telephone listening device * Wire transfer, a method of sending money directly between banks Types of wire * Barbed wire, steel fencing wire * Chicken wire, a mesh of wire * Concertina wire, a type of barbed wire or razor wire * Copper-clad aluminium wire, inner aluminium core and outer copper cladding * Electrical wiring, electrical installation of cabling and associated devices * Electroluminescent wire, thin copper wire coated in a phosphor * Glass-coated wire, fine glass-coated metal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Resistivity And Conductivity
Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows electric current. Resistivity is commonly represented by the Greek letter (rho). The SI unit of electrical resistivity is the ohm-meter (Ω⋅m). For example, if a solid cube of material has sheet contacts on two opposite faces, and the resistance between these contacts is , then the resistivity of the material is . Electrical conductivity or specific conductance is the reciprocal of electrical resistivity. It represents a material's ability to conduct electric current. It is commonly signified by the Greek letter ( sigma), but (kappa) (especially in electrical engineering) and (gamma) are sometimes used. The SI unit of electrical conductivity is siemens per metre (S/m). Resistivity and conductivity are intensi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluid Dynamics
In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids— liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) and hydrodynamics (the study of liquids in motion). Fluid dynamics has a wide range of applications, including calculating forces and moments on aircraft, determining the mass flow rate of petroleum through pipelines, predicting weather patterns, understanding nebulae in interstellar space and modelling fission weapon detonation. Fluid dynamics offers a systematic structure—which underlies these practical disciplines—that embraces empirical and semi-empirical laws derived from flow measurement and used to solve practical problems. The solution to a fluid dynamics problem typically involves the calculation of various properties of the fluid, such as flow velocity, pressure, density, and temperature, as functions of space and time. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron's mass is approximately 1/1836 that of the proton. Quantum mechanical properties of the electron include an intrinsic angular momentum ( spin) of a half-integer value, expressed in units of the reduced Planck constant, . Being fermions, no two electrons can occupy the same quantum state, in accordance with the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of both particles and waves: They can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer de Broglie wavele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phonon
In physics, a phonon is a collective excitation in a periodic, Elasticity (physics), elastic arrangement of atoms or molecules in condensed matter physics, condensed matter, specifically in solids and some liquids. A type of quasiparticle, a phonon is an excited state in the quantum mechanical Quantization (physics), quantization of the mode of vibration, modes of vibrations for elastic structures of interacting particles. Phonons can be thought of as quantized sound waves, similar to photons as quantized light waves. The study of phonons is an important part of condensed matter physics. They play a major role in many of the physical properties of condensed matter systems, such as thermal conductivity and electrical conductivity, as well as in models of neutron scattering and related effects. The concept of phonons was introduced in 1932 by Soviet Union, Soviet physicist Igor Tamm. The name ''phonon'' comes from the Ancient Greek language, Greek word (), which translates to ''so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Magnetoresistance
Giant magnetoresistance (GMR) is a quantum mechanical magnetoresistance effect observed in multilayers composed of alternating ferromagnetic and non-magnetic conductive layers. The 2007 Nobel Prize in Physics was awarded to Albert Fert and Peter Grünberg for the discovery of GMR. The effect is observed as a significant change in the electrical resistance depending on whether the magnetization of adjacent ferromagnetic layers are in a parallel or an antiparallel alignment. The overall resistance is relatively low for parallel alignment and relatively high for antiparallel alignment. The magnetization direction can be controlled, for example, by applying an external magnetic field. The effect is based on the dependence of electron scattering on spin orientation. The main application of GMR is in magnetic field sensors, which are used to read data in hard disk drives, biosensors, microelectromechanical systems (MEMS) and other devices. GMR multilayer structures are also used in m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
