“resistance”的概念、定义、翻译、参考文献-科学参考

resistance

Physics

Symbol R. The ratio of the potential difference across an electrical component to the current passing through it. It is thus a measure of the component’s opposition to the flow of electric charge. In general, the resistance of a metallic conductor increases with temperature, whereas the resistance of a semiconductor decreases with temperature.

Chemical Engineering

1. A force, such as friction, that opposes the direction of motion having the effect of slowing a body such as fluid flowing in a pipe.

2. The ability of the human body to withstand the harmful effects of chemical pollutants, viruses, microorganisms, and physical conditions such as extremes of temperature and pressure.

Electronics and Electrical Engineering

1. (symbol: R; unit: ohm) The tendency of a material to resist the passage of an electric current and to convert electrical energy into heat energy. It is the ratio of the applied potential difference across a conductor to the current flowing through it (see Ohm’s law). If the current is an alternating current the resistance is the real part – the resistive component – of the electrical impedance, Z:
$Z = R + j X$
where j is equal to √−1 and X is the reactance.
2. See resistor.

Biology

1. (in microbiology) The degree to which pathogenic microorganisms remain unaffected by antibiotics and other drugs. Resistance to antibiotics is a growing and serious problem in human and veterinary medicine, to the extent that some strains of pathogen are now susceptible to very few drugs. Genes for antibiotic resistance are often carried on plasmids or transposons, which can spread across species barriers.
2. (in ecology)
1. a. The degree to which a pest can withstand the effects of a pesticide. It depends on the selection and spread within a pest population of genes that confer the ability to destroy, or minimize the effects of, a pesticide.
2. b. See environmental resistance.
3. (in immunology) The degree of immunity to infection that an animal possesses.

Geography

The ability of a system to avoid or minimize responses to externally imposed changes. Resistance has two main aspects: some indication or measure of strength, chemical or mechanical stability, or susceptibility to modification; and absorption, generally assessed as some measure of capacity (A. Goudie and K. J. Gregory 2011). In hydrology, resistance is the friction force counterbalancing the downslope gravitational force (L. B. Leopold et al. 1964). Resistance is a function of the surface area in contact with the flow, and so flow becomes more efficient when the ratio of the flow cross-sectional area A to the wetted perimeter P is high (defining the hydraulic radius R). See Smith et al. (2007) PPG 31, 4 on applying flow resistance equations to overland flows.

单词	resistance
释义	resistance Physics Symbol R. The ratio of the potential difference across an electrical component to the current passing through it. It is thus a measure of the component’s opposition to the flow of electric charge. In general, the resistance of a metallic conductor increases with temperature, whereas the resistance of a semiconductor decreases with temperature. Chemical Engineering 1. A force, such as friction, that opposes the direction of motion having the effect of slowing a body such as fluid flowing in a pipe. 2. The ability of the human body to withstand the harmful effects of chemical pollutants, viruses, microorganisms, and physical conditions such as extremes of temperature and pressure. Electronics and Electrical Engineering 1. (symbol: R; unit: ohm) The tendency of a material to resist the passage of an electric current and to convert electrical energy into heat energy. It is the ratio of the applied potential difference across a conductor to the current flowing through it (see Ohm’s law). If the current is an alternating current the resistance is the real part – the resistive component – of the electrical impedance, Z: $Z = R + j X$ where j is equal to √−1 and X is the reactance. 2. See resistor. Biology 1. (in microbiology) The degree to which pathogenic microorganisms remain unaffected by antibiotics and other drugs. Resistance to antibiotics is a growing and serious problem in human and veterinary medicine, to the extent that some strains of pathogen are now susceptible to very few drugs. Genes for antibiotic resistance are often carried on plasmids or transposons, which can spread across species barriers. 2. (in ecology) a. The degree to which a pest can withstand the effects of a pesticide. It depends on the selection and spread within a pest population of genes that confer the ability to destroy, or minimize the effects of, a pesticide. b. See environmental resistance. 3. (in immunology) The degree of immunity to infection that an animal possesses. Geography The ability of a system to avoid or minimize responses to externally imposed changes. Resistance has two main aspects: some indication or measure of strength, chemical or mechanical stability, or susceptibility to modification; and absorption, generally assessed as some measure of capacity (A. Goudie and K. J. Gregory 2011). In hydrology, resistance is the friction force counterbalancing the downslope gravitational force (L. B. Leopold et al. 1964). Resistance is a function of the surface area in contact with the flow, and so flow becomes more efficient when the ratio of the flow cross-sectional area A to the wetted perimeter P is high (defining the hydraulic radius R). See Smith et al. (2007) PPG 31, 4 on applying flow resistance equations to overland flows.
随便看	Cape Canaveral Capella Cape Photographic Durchmusterung Cape photometry Cape RI photometry Cape St Vincent, Battle of (14 February 1797) Capetian (987–1328) Cape Verde capex Cape York meteorite Caph capillarity capillary capillary action capillary bound water capillary electrophoresis capillary flow capillary flow number capillary fringe capillary gel electrophoresis capillary moisture capillary water capillary wave capillary zone capillary zone electrophoresis