|
ISO 31
ISO 31 (Physical quantity, Quantities and Physical unit, units, International Organization for Standardization, 1992) is a superseded international standard concerning physical quantities, units of measurement, their interrelationships and their presentation. It was revised and replaced by ISO/IEC 80000. Parts The standard comes in 14 parts: *ISO 31-0: General principles (replaced by ISO/IEC 80000-1:2009) *ISO 31-1: Space and time (replaced by ISO/IEC 80000-3:2007) *ISO 31-2: Periodic and related phenomena (replaced by ISO/IEC 80000-3:2007) *ISO 31-3: Mechanics (replaced by ISO/IEC 80000-4:2006) *ISO 31-4: Heat (replaced by ISO/IEC 80000-5) *ISO 31-5: Electricity and magnetism (replaced by ISO/IEC 80000-6) *ISO 31-6: Light and related electromagnetic radiations (replaced by ISO/IEC 80000-7) *ISO 31-7: Acoustics (replaced by ISO/IEC 80000-8:2007) *ISO 31-8: Physical chemistry and molecular physics (replaced by ISO/IEC 80000-9) *ISO 31-9: Atomic and nuclear physics (replac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Quantity
A physical quantity (or simply quantity) is a property of a material or system that can be Quantification (science), quantified by measurement. A physical quantity can be expressed as a ''value'', which is the algebraic multiplication of a ''numerical value'' and a ''unit of measurement''. For example, the physical quantity mass, symbol ''m'', can be quantified as ''m'n''kg, where ''n'' is the numerical value and kg is the unit symbol (for kilogram). Quantities that are vectors have, besides numerical value and unit, direction or orientation in space. Components Following ISO 80000-1, any value or Magnitude (mathematics), magnitude of a physical quantity is expressed as a comparison to a unit of that quantity. The ''value'' of a physical quantity ''Z'' is expressed as the product of a ''numerical value'' (a pure number) and a unit [''Z'']: :Z = \ \times [Z] For example, let Z be "2 metres"; then, \ = 2 is the numerical value and [Z] = \mathrm is the unit. Conversely, the nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetism
Magnetism is the class of physical attributes that occur through a magnetic field, which allows objects to attract or repel each other. Because both electric currents and magnetic moments of elementary particles give rise to a magnetic field, magnetism is one of two aspects of electromagnetism. The most familiar effects occur in ferromagnetic materials, which are strongly attracted by magnetic fields and can be magnetized to become permanent magnets, producing magnetic fields themselves. Demagnetizing a magnet is also possible. Only a few substances are ferromagnetic; the most common ones are iron, cobalt, nickel, and their alloys. All substances exhibit some type of magnetism. Magnetic materials are classified according to their bulk susceptibility. Ferromagnetism is responsible for most of the effects of magnetism encountered in everyday life, but there are actually several types of magnetism. Paramagnetic substances, such as aluminium and oxygen, are weakly attracted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionizing Radiation
Ionizing (ionising) radiation, including Radioactive decay, nuclear radiation, consists of subatomic particles or electromagnetic waves that have enough energy per individual photon or particle to ionization, ionize atoms or molecules by detaching electrons from them. Some particles can travel up to 99% of the speed of light, and the electromagnetic waves are on the high-energy portion of the electromagnetic spectrum. Gamma rays, X-rays, and the higher energy vacuum ultraviolet, ultraviolet part of the electromagnetic spectrum are ionizing radiation; whereas the lower energy ultraviolet, visible light, infrared, microwaves, and radio waves are non-ionizing radiation. Nearly all types of laser light are non-ionizing radiation. The boundary between ionizing and non-ionizing radiation in the ultraviolet area cannot be sharply defined, as different molecules and atoms ionize at Ionization energies of the elements (data page), different energies. The energy of ionizing radiation starts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Reaction
In nuclear physics and nuclear chemistry, a nuclear reaction is a process in which two atomic nucleus, nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides. Thus, a nuclear reaction must cause a transformation of at least one nuclide to another. If a nucleus interacts with another nucleus or particle, they then separate without changing the nature of any nuclide, the process is simply referred to as a type of nuclear scattering, rather than a nuclear reaction. In principle, a reaction can involve more than two particles collision, colliding, but because the probability of three or more nuclei to meet at the same time at the same place is much less than for two nuclei, such an event is exceptionally rare (see triple alpha process for an example very close to a three-body nuclear reaction). The term "nuclear reaction" may refer either to a change in a nuclide induced by collision with another particle or to a spontaneous change of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO 31-10
ISO 31-10 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to ''nuclear reactions and ionizing radiation Ionizing (ionising) radiation, including Radioactive decay, nuclear radiation, consists of subatomic particles or electromagnetic waves that have enough energy per individual photon or particle to ionization, ionize atoms or molecules by detaching ...s''. It gives names and symbols for 70 quantities and units. Where appropriate, conversion factors are also given. The standard was withdrawn in 2009 and replaced by ISO 80000-10. Its definitions include: External links ISO 31-10:1992 - Quantities and units - Part 10: Nuclear reactions and ionizing radiations #00031-10 Radioactivity quantities {{measurement-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Physics
Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions, in addition to the study of other forms of nuclear matter. Nuclear physics should not be confused with atomic physics, which studies the atom as a whole, including its electrons. Discoveries in nuclear physics have led to applications in many fields such as nuclear power, nuclear weapons, nuclear medicine and magnetic resonance imaging, industrial and agricultural isotopes, ion implantation in materials engineering, and radiocarbon dating in geology and archaeology. Such applications are studied in the field of nuclear engineering. Particle physics evolved out of nuclear physics and the two fields are typically taught in close association. Nuclear astrophysics, the application of nuclear physics to astrophysics, is crucial in explaining the inner workings of stars and the origin of the chemical elements. History The history of nuclear physics as a discipline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO 31-9
ISO 31 (Quantities and units, International Organization for Standardization, 1992) is a superseded international standard concerning physical quantities, units of measurement, their interrelationships and their presentation. It was revised and replaced by ISO/IEC 80000. Parts The standard comes in 14 parts: * ISO 31-0: General principles (replaced by ISO/IEC 80000-1:2009) *ISO 31-1: Space and time (replaced by ISO/IEC 80000-3:2007) * ISO 31-2: Periodic and related phenomena (replaced by ISO/IEC 80000-3:2007) * ISO 31-3: Mechanics (replaced by ISO/IEC 80000-4:2006) *ISO 31-4: Heat (replaced by ISO/IEC 80000-5) * ISO 31-5: Electricity and magnetism (replaced by ISO/IEC 80000-6) * ISO 31-6: Light and related electromagnetic radiations (replaced by ISO/IEC 80000-7) * ISO 31-7: Acoustics (replaced by ISO/IEC 80000-8:2007) *ISO 31-8: Physical chemistry and molecular physics (replaced by ISO/IEC 80000-9) * ISO 31-9: Atomic and nuclear physics (replaced by ISO/IEC 80000-10) * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Physics
Molecular physics is the study of the physical properties of molecules and molecular dynamics. The field overlaps significantly with physical chemistry, chemical physics, and quantum chemistry. It is often considered as a sub-field of atomic, molecular, and optical physics. Research groups studying molecular physics are typically designated as one of these other fields. Molecular physics addresses phenomena due to both molecular structure and individual atomic processes within molecules. Like atomic physics, it relies on a combination of classical and quantum mechanics to describe interactions between electromagnetic radiation and matter. Experiments in the field often rely heavily on techniques borrowed from atomic physics, such as spectroscopy and scattering. Molecular structure In a molecule, both the electrons and nuclei experience similar-scale forces from the Coulomb interaction. However, the nuclei remain at nearly fixed locations in the molecule while the electrons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during chemical reaction, reactions with other chemical substance, substances. Chemistry also addresses the nature of chemical bonds in chemical compounds. In the scope of its subject, chemistry occupies an intermediate position between physics and biology. It is sometimes called the central science because it provides a foundation for understanding both Basic research, basic and Applied science, applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant growth (botany), the formation of igneous rocks (geology), how atmospheric ozone is formed and how environmental pollutants are degraded (ecology), the prop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO 31-8
ISO 31-8 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to ''physical chemistry and molecular physics''. Quantities and units Notes In the tables of quantities and their units, the ISO 31-8 standard shows symbols for substances as subscripts (e.g., ''c''B, ''w''B, ''p''B). It also notes that it is generally advisable to put symbols for substances and their states in parentheses on the same line, as in ''c''(H2SO4). Normative annexes Annex A: Names and symbols of the chemical elements This annex contains a list of elements by atomic number, giving the names and standard symbols of the chemical elements from atomic number 1 (hydrogen, H) to 109 ( unnilennium, Une). The list given in ISO 31-8:1992 was quoted from the 1998 IUPAC "Green Book" Quantities, Units and Symbols in Physical Chemistry and adds in some cases in parentheses the Latin name for information, where the standard symbol has no relation to the English ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acoustics
Acoustics is a branch of physics that deals with the study of mechanical waves in gases, liquids, and solids including topics such as vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics technology may be called an Acoustical engineering, acoustical engineer. The application of acoustics is present in almost all aspects of modern society with the most obvious being the audio and noise control industries. Hearing (sense), Hearing is one of the most crucial means of survival in the animal world and speech is one of the most distinctive characteristics of human development and culture. Accordingly, the science of acoustics spreads across many facets of human society—music, medicine, architecture, industrial production, warfare and more. Likewise, animal species such as songbirds and frogs use sound and hearing as a key element of mating rituals or for marking territories. Art, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO 31-7
ISO 31-7 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to acoustics Acoustics is a branch of physics that deals with the study of mechanical waves in gases, liquids, and solids including topics such as vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician .... It is superseded by ISO 80000-8. Its definitions include: References Acoustics #00031-07 {{Standard-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
