“inversion”的概念、定义、翻译、参考文献-科学参考

inversion

Chemistry

1. A chemical reaction involving a change from one optically active configuration to the opposite configuration. The Walden inversion is an example. See also nucleophilic substitution.
2. An operation that reverses all the signs of the coordinates of a system, i.e. (x, y, z) is taken into (–x, –y, –z). If a system is invariant under this operation, it is said to have inversion symmetry. See also centrosymmetric molecule.

Electronics and Electrical Engineering

The production of a layer of opposite polarity at the surface of a semiconductor under the influence of an electric field, usually an applied one. Spontaneous inversion can occur in the surface of p-type material when it is in contact with an insulating layer due to the presence of positive ions in the insulator. Inversion can only occur when sufficient mobile minority carriers are present in the semiconductor material, otherwise a depletion layer forms. The phenomenon is utilized for formation of the channel of an insulated-gate field-effect transistor. See also MOS capacitor.

Geology and Earth Sciences

A reversal of a particular trend.
1. A rock sequence in which the younger sediments are at the bottom. Inversion can be caused by overfolding or thrusting. It is a major feature of an accretionary wedge in which progressively younger oceanic and trench sediment is underthrust, so that while each thrust slice is not inverted, each new thrust affects younger sediment, so producing the inversion. In a positive inversion, normal faults on passive margins become thrusts on collision. In a negative inversion thrusts become normal faults at the end of an orogeny. The inversion of sediments takes place during strike-slip faulting.
2. During an orogeny, the uplift that follows subsidence as a reversal of vertical direction.
3. (velocity inversion) Seismic velocity usually increases with depth, but occasionally a zone of anomalously low velocity occurs between layers of higher velocities giving rise to a velocity inversion.
4. See polarity reversal, geomagnetic.
5. See temperature inversion.

Geography

The increase of air temperatures with height. (This is the reverse of the more common situation in which air cools with height.) Inversions occur: when strong, nocturnal, terrestrial radiation cools the Earth’s surface and therefore chills the air which is in contact with the ground (Lapworth (2003) Qly. J. Royal Met. Soc. 129); when cold air flows into valley floors, displacing warmer air (LeMone et al. (2003) J. Atmos. Scis 60); where a stream of warm air crosses the cool air over a cold ocean current (Vihma et al. (2003) Boundary-Layer Met. 107); where warm air rises over a cold front (Ross and Orlanski (1978) J. Atmos. Scis 35, 3); when air from the upper troposphere, subsiding in a warm anticyclone, is compressed and adiabatically warmed. The boundary between the top of the cold air and the beginning of the inversion is an inversion lid.
See also trade wind inversion.

Philosophy

In traditional logic, producing the obverse of a proposition.

单词	inversion
释义	inversion Chemistry 1. A chemical reaction involving a change from one optically active configuration to the opposite configuration. The Walden inversion is an example. See also nucleophilic substitution. 2. An operation that reverses all the signs of the coordinates of a system, i.e. (x, y, z) is taken into (–x, –y, –z). If a system is invariant under this operation, it is said to have inversion symmetry. See also centrosymmetric molecule. Electronics and Electrical Engineering The production of a layer of opposite polarity at the surface of a semiconductor under the influence of an electric field, usually an applied one. Spontaneous inversion can occur in the surface of p-type material when it is in contact with an insulating layer due to the presence of positive ions in the insulator. Inversion can only occur when sufficient mobile minority carriers are present in the semiconductor material, otherwise a depletion layer forms. The phenomenon is utilized for formation of the channel of an insulated-gate field-effect transistor. See also MOS capacitor. Geology and Earth Sciences A reversal of a particular trend. 1. A rock sequence in which the younger sediments are at the bottom. Inversion can be caused by overfolding or thrusting. It is a major feature of an accretionary wedge in which progressively younger oceanic and trench sediment is underthrust, so that while each thrust slice is not inverted, each new thrust affects younger sediment, so producing the inversion. In a positive inversion, normal faults on passive margins become thrusts on collision. In a negative inversion thrusts become normal faults at the end of an orogeny. The inversion of sediments takes place during strike-slip faulting. 2. During an orogeny, the uplift that follows subsidence as a reversal of vertical direction. 3. (velocity inversion) Seismic velocity usually increases with depth, but occasionally a zone of anomalously low velocity occurs between layers of higher velocities giving rise to a velocity inversion. 4. See polarity reversal, geomagnetic. 5. See temperature inversion. Geography The increase of air temperatures with height. (This is the reverse of the more common situation in which air cools with height.) Inversions occur: when strong, nocturnal, terrestrial radiation cools the Earth’s surface and therefore chills the air which is in contact with the ground (Lapworth (2003) Qly. J. Royal Met. Soc. 129); when cold air flows into valley floors, displacing warmer air (LeMone et al. (2003) J. Atmos. Scis 60); where a stream of warm air crosses the cool air over a cold ocean current (Vihma et al. (2003) Boundary-Layer Met. 107); where warm air rises over a cold front (Ross and Orlanski (1978) J. Atmos. Scis 35, 3); when air from the upper troposphere, subsiding in a warm anticyclone, is compressed and adiabatically warmed. The boundary between the top of the cold air and the beginning of the inversion is an inversion lid. See also trade wind inversion. Philosophy In traditional logic, producing the obverse of a proposition.
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