|
NASU Institute Of Physics
The Institute of Physics (IOP) of the National Academy of Sciences of Ukraine ( uk, Інститут фізики Національної академії наук України) founded in 1926 is the oldest research institution of physical science within the academy. Being on the path of both infrastructure development and research diversification for more than 80 years, the institute has eventually originated five more specialized research institutions. Currently, the institute employs more than 300 researchers (together with two full members and eight corresponding members of the NASU) and around 200 peoples of supporting personnel. It has more than 20 scientific units (including the state-of-the-art Femtosecond Laser Complex) which are grouped around four research programs Traditionally, the institute is focused on fundamental research. At the same time, applied research on cryogenics, LC displays, laser systems, pyroelectric detectors, biophysics and plasma technologies s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Institute Of Physics Kyiv Ukraine Building1
An institute is an organisational body created for a certain purpose. They are often research organisations ( research institutes) created to do research on specific topics, or can also be a professional body. In some countries, institutes can be part of a university or other institutions of higher education, either as a group of departments or an autonomous educational institution without a traditional university status such as a "university institute" (see Institute of Technology). In some countries, such as South Korea and India, private schools are sometimes referred to as institutes, and in Spain, secondary schools are referred to as institutes. Historically, in some countries institutes were educational units imparting vocational training and often incorporating libraries, also known as mechanics' institutes. The word "institute" comes from a Latin word ''institutum'' meaning "facility" or "habit"; from ''instituere'' meaning "build", "create", "raise" or "edu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antonina Prikhot'ko
Antonina Fedorivna Prykhotko (; 26 April 1906, Pyatigorsk – 29 September 1995, Kyiv), was a Soviet and Ukrainian experimental physicist. She was an Academician of the National Academy of Sciences of Ukraine and is known for her fundamental contributions to the condensed matter spectroscopy. Career Prykhotko was accepted to the Leningrad Polytechnical Institute in 1923 and graduated in 1929. Still as a Junior, she started research on spectroscopy under the supervision of Ivan V. Obreimov, and finally earned a PhD in this field under his guidance. In 1930, she moved to the newly established Kharkiv Institute of Physics and Technology for working with Obreimov on low-temperature spectroscopy of molecular crystals, a field pioneered by him, in the first in the USSR cryogenic laboratory created by Lev Shubnikov. This research was primary focused on comparing the spectra of vapors and crystals of weakly interacting molecules that at low temperature manifest a number of narrow band ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetostriction
Magnetostriction (cf. electrostriction) is a property of magnetic materials that causes them to change their shape or dimensions during the process of magnetization. The variation of materials' magnetization due to the applied magnetic field changes the magnetostrictive strain until reaching its saturation value, λ. The effect was first identified in 1842 by James Joule when observing a sample of iron. This effect causes energy loss due to frictional heating in susceptible ferromagnetic cores. The effect is also responsible for the low-pitched humming sound that can be heard coming from transformers, where oscillating AC currents produce a changing magnetic field. Explanation Internally, ferromagnetic materials have a structure that is divided into '' domains'', each of which is a region of uniform magnetization. When a magnetic field is applied, the boundaries between the domains shift and the domains rotate; both of these effects cause a change in the material's dimensions. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Magnetic Resonance
Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are perturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with a frequency characteristic of the magnetic field at the nucleus. This process occurs near resonance, when the oscillation frequency matches the intrinsic frequency of the nuclei, which depends on the strength of the static magnetic field, the chemical environment, and the magnetic properties of the isotope involved; in practical applications with static magnetic fields up to ca. 20 tesla, the frequency is similar to VHF and UHF television broadcasts (60–1000 MHz). NMR results from specific magnetic properties of certain atomic nuclei. Nuclear magnetic resonance spectroscopy is widely used to determine the structure of organic molecules in solution and study molecular physics and crystals as well as non-crystalline materials. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-temperature Superconductivity
High-temperature superconductors (abbreviated high-c or HTS) are defined as materials that behave as superconductors at temperatures above , the boiling point of liquid nitrogen. The adjective "high temperature" is only in respect to previously known superconductors, which function at even colder temperatures close to absolute zero. In absolute terms, these "high temperatures" are still far below ambient, and therefore require cooling. The first high-temperature superconductor was discovered in 1986, by IBM researchers Bednorz and Müller, who were awarded the Nobel Prize in Physics in 1987 "for their important break-through in the discovery of superconductivity in ceramic materials". Most high-c materials are type-II superconductors. The major advantage of high-temperature superconductors is that they can be cooled by using liquid nitrogen, as opposed to the previously known superconductors which require expensive and hard-to-handle coolants, primarily liquid helium. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quasiparticle
In physics, quasiparticles and collective excitations are closely related emergent phenomena arising when a microscopically complicated system such as a solid behaves as if it contained different weakly interacting particles in vacuum. For example, as an electron travels through a semiconductor, its motion is disturbed in a complex way by its interactions with other electrons and with atomic nucleus, atomic nuclei. The electron behaves as though it has a different effective mass (solid-state physics), effective mass travelling unperturbed in vacuum. Such an electron is called an ''electron quasiparticle''. In another example, the aggregate motion of electrons in the valence band of a semiconductor or a hole band in a metal behave as though the material instead contained positively charged quasiparticles called ''electron holes''. Other quasiparticles or collective excitations include the ''phonon'', a quasiparticle derived from the vibrations of atoms in a solid, and the ''plasmo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exciton
An exciton is a bound state of an electron and an electron hole which are attracted to each other by the electrostatic Coulomb force. It is an electrically neutral quasiparticle that exists in insulators, semiconductors and some liquids. The exciton is regarded as an elementary excitation of condensed matter that can transport energy without transporting net electric charge. An exciton can form when a material absorbs a photon of higher energy than its bandgap. This excites an electron from the valence band into the conduction band. In turn, this leaves behind a positively charged electron hole (an abstraction for the location from which an electron was moved). The electron in the conduction band is then less attracted to this localized hole due to the repulsive Coulomb forces from large numbers of electrons surrounding the hole and excited electron. These repulsive forces provide a stabilizing energy balance. Consequently, the exciton has slightly less energy than the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Crystal
Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. There are many types of LC phases, which can be distinguished by their optical properties (such as textures). The contrasting textures arise due to molecules within one area of material ("domain") being oriented in the same direction but different areas having different orientations. LC materials may not always be in a LC state of matter (just as water may be ice or water vapor). Liquid crystals can be divided into 3 main types: * thermotropic, *lyotropic, and * metallotropic. Thermotropic and lyotropic liquid crystals consist mostly of organic molecules, although a few minerals are also known. Thermotropic LCs exhibit a phase transition into the LC phase as temperature changes. Lyotropic LCs exhibit phase transitions as a function of b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
