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Rydberg Matter
Rydberg matter is an exotic phase of matter formed by Rydberg atoms; it was predicted around 1980 by É. A. Manykin, M. I. Ozhovan and P. P. Poluéktov. It has been formed from various elements like caesium, potassium, hydrogen and nitrogen; studies have been conducted on theoretical possibilities like sodium, beryllium, magnesium and calcium. It has been suggested to be a material that diffuse interstellar bands may arise from. Circular Rydberg states, where the outermost electron is found in a planar circular orbit, are the most long-lived, with lifetimes of up to several hours, and are the most common. Physical Rydberg matter consists of usually hexagonal planar clusters; these cannot be very big because of the retardation effect caused by the finite velocity of the speed of light. Hence, they are not gases or plasmas; nor are they solids or liquids; they are most similar to dusty plasmas with small clusters in a gas. Though Rydberg matter can be studied in the laborator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase (matter)
In the physical sciences, a phase is a region of space (a thermodynamic system), throughout which all physical properties of a material are essentially uniform. Examples of physical properties include density, index of refraction, magnetization and chemical composition. A simple description is that a phase is a region of material that is chemically uniform, physically distinct, and (often) mechanically separable. In a system consisting of ice and water in a glass jar, the ice cubes are one phase, the water is a second phase, and the humid air is a third phase over the ice and water. The glass of the jar is another separate phase. (See ) The term ''phase'' is sometimes used as a synonym for state of matter, but there can be several immiscible phases of the same state of matter. Also, the term ''phase'' is sometimes used to refer to a set of equilibrium states demarcated in terms of state variables such as pressure and temperature by a phase boundary on a phase diagram. Bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review A
''Physical Review A'' (also known as PRA) is a monthly peer-reviewed scientific journal published by the American Physical Society covering atomic, molecular, and optical physics and quantum information. the editor was Jan M. Rost (Max Planck Institute for the Physics of Complex Systems). History In 1893, the ''Physical Review'' was established at Cornell University. It was taken over by the American Physical Society (formed in 1899) in 1913. In 1970, ''Physical Review'' was subdivided into ''Physical Review A'', ''B'', ''C'', and ''D''. At that time section ''A'' was subtitled ''Physical Review A: General Physics''. In 1990 a process was started to split this journal into two, resulting in the creation of ''Physical Review E'' in 1993. Hence, in 1993, ''Physical Review A'' changed its statement of scope to ''Atomic, Molecular and Optical Physics.'' In January 2007, the section of ''Physical Review E'' that published papers on classical optics was merged into ''Physical Review ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principal Quantum Number
In quantum mechanics, the principal quantum number (symbolized ''n'') is one of four quantum numbers assigned to each electron in an atom to describe that electron's state. Its values are natural numbers (from 1) making it a discrete variable. Apart from the principal quantum number, the other quantum numbers for bound electrons are the azimuthal quantum number ''ℓ'', the magnetic quantum number ''ml'', and the spin quantum number ''s''. Overview and history As ''n'' increases, the electron is also at a higher energy and is, therefore, less tightly bound to the nucleus. For higher ''n'' the electron is farther from the nucleus, on average. For each value of ''n'' there are ''n'' accepted ''ℓ'' (azimuthal) values ranging from 0 to ''n'' − 1 inclusively, hence higher-''n'' electron states are more numerous. Accounting for two states of spin, each ''n''- shell can accommodate up to 2''n''2 electrons. In a simplistic one-electron model described bel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decay Schematic
Decay may refer to: Science and technology * Bit decay, in computing * Software decay, in computing * Distance decay, in geography * Decay time (fall time), in electronics Biology * Decomposition of organic matter * Tooth decay (dental caries), in dentistry * Mitochondrial decay, in genetics Physics * Orbital decay, the process of prolonged reduction in the height of a satellite's orbit * Particle decay * Radioactive decay * Optical decay, in quantum physics Mathematics * Exponential decay Psychology and sociology * Decay theory, in psychology and memory * Social decay (decadence), in sociology * Urban decay, in sociology Entertainment * Network decay (channel drift), in television programming * Decay (DC Comics), a comic book character * '' Half-Life: Decay'', a 2001 video game add-on * Deekay, a Danish production team * Decay (professional wrestling), a professional wrestling stable in TNA Wrestling Film * ''Decay'' (2012 film), a 2012 zombie film set at the La ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raman Spectroscopy
Raman spectroscopy () (named after Indian physicist C. V. Raman) is a spectroscopic technique typically used to determine vibrational modes of molecules, although rotational and other low-frequency modes of systems may also be observed. Raman spectroscopy is commonly used in chemistry to provide a structural fingerprint by which molecules can be identified. Raman spectroscopy relies upon inelastic scattering of photons, known as Raman scattering. A source of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range is used, although X-rays can also be used. The laser light interacts with molecular vibrations, phonons or other excitations in the system, resulting in the energy of the laser photons being shifted up or down. The shift in energy gives information about the vibrational modes in the system. Infrared spectroscopy typically yields similar yet complementary information. Typically, a sample is illuminated with a laser beam. Electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delocalisation
In chemistry, delocalized electrons are electrons in a molecule, ion or solid metal that are not associated with a single atom or a covalent bond.IUPAC Gold Boo''delocalization''/ref> The term delocalization is general and can have slightly different meanings in different fields: * In organic chemistry, it refers to resonance in conjugated systems and aromatic compounds. * In solid-state physics, it refers to free electrons that facilitate electrical conduction. * In quantum chemistry, it refers to molecular orbital electrons that have extended over several adjacent atoms. Resonance In the simple aromatic ring of benzene, the delocalization of six π electrons over the C6 ring is often graphically indicated by a circle. The fact that the six C-C bonds are equidistant is one indication that the electrons are delocalized; if the structure were to have isolated double bonds alternating with discrete single bonds, the bond would likewise have alternating longer and shorter le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Probing
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light which is ''coherent''. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers and lidar (light detection and ranging). Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum. Alternatively, temporal coherence can be used to produce ultrashort pulses of ligh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dusty Plasma
A dusty plasma is a plasma containing micrometer (10−6) to nanometer (10−9) sized particles suspended in it. Dust particles are charged and the plasma and particles behave as a plasma. Dust particles may form larger particles resulting in "grain plasmas". Due to the additional complexity of studying plasmas with charged dust particles, dusty plasmas are also known as complex plasmas. Dusty plasmas are encountered in: * Space plasmas * The mesosphere of the Earth * Specifically designed laboratory experiments Dusty plasmas are interesting because the presence of particles significantly alters the charged particle equilibrium leading to different phenomena. It is a field of current research. Electrostatic coupling between the grains can vary over a wide range so that the states of the dusty plasma can change from weakly coupled (gaseous) to crystalline. Such plasmas are of interest as a non-Hamiltonian system of interacting particles and as a means to study generic fundament ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retardation Effect
Retardation is the act or result of delaying; the extent to which anything is retarded or delayed; that which retards or delays. Retardation or retarded or similar may refer to: Medicine and biology * Mental retardation, also known as intellectual disability, a disorder characterized by significantly impaired cognitive functioning and deficits in adaptive behaviors * Psychomotor retardation, a slowing-down of thought and a reduction of physical movements in an individual * A form of heterochrony, able to cause effects such as neoteny, retention by adults of traits previously seen only in the young Physics and engineering * Retardation factor, in chromatography, the fraction of an analyte in the mobile phase of a chromatographic system * Retarded potential, in electrodynamics, electromagnetic potentials generated by time-varying electric current or charge distributions in the past * Retarded time, time when an electromagnetic field began to propagate from a point in a charge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cluster (physics)
In physics, the term clusters denotes small, polyatomic particles. As a rule of thumb, any particle made of between 3×100 and 3×107 atoms is considered a cluster. The term can also refer to the organization of protons and neutrons within an atomic nucleus, e.g. the alpha particle (also known as "α-cluster"), consisting of two protons and two neutrons (as in a helium nucleus). Overview Although first reports of cluster species date back to the 1940s, cluster science emerged as a separate direction of research in the 1980s, One purpose of the research was to study the gradual development of collective phenomena which characterize a bulk solid. For example, these are the color of a body, its electrical conductivity, its ability to absorb or reflect light, and magnetic phenomena such as ferro-, ferri-, or antiferromagnetism. These are typical collective phenomena which only develop in an aggregate of a large number of atoms. It was found that collective phenomena break down for v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WS Unit Cell
WS, Ws, or ws may refer to: Businesses and organizations * Ware Shoals Railroad (reporting mark WS) * WestJet (IATA airline code WS) * Society of Writers to Her Majesty's Signet, in post-nomial abbreviation * Williams Street, the production arm for Cartoon Network’s nighttime programming block, Adult Swim. * Warm Showers, a non-profit hospitality exchange network for world cyclists. * Williams-Sonoma, Inc., American kitchenware and home furnishings retailer. Places * WS postcode area, West Midlands, UK * Samoa (ISO 3166-1 country code WS) * Winschoten railway station, the Netherlandsm station code Science and technology * .ws, the Internet country code top-level domain for Samoa * ws:// WebSocket protocol prefix in a URI * Watt second (Ws) or Joule, a unit of energy * Web service, software system designed to support machine-to-machine interaction over the Web * Werner syndrome, premature aging * Williams syndrome, a developmental disorder * WonderSwan, handheld game console ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
