“desert”的概念、定义、翻译、参考文献-科学参考

desert

Biology

A major terrestrial biome characterized by low rainfall. Hot deserts, such as the Sahara and Kalahari deserts of Africa, have a rainfall of less than 25 cm a year and extremely high daytime temperatures (in some cases up to 50°C). Vegetation is sparse, and desert plants are adapted to conserve water and take advantage of the rain when it falls. The perennials include xerophytic trees and shrubs (see xerophyte) and succulents, such as cacti; many succulents show crassulacean acid metabolism. Annual plants are ephemerals, lying dormant as seeds for most of the year and completing their life cycle in the brief rainy periods. Desert animals are typically nocturnal or active at dawn and dusk, thus avoiding the extreme daytime temperatures. In cold deserts, such as the high plateau of Antarctica, winter temperatures can fall as low as –80°C.

Geology and Earth Sciences

A term which has no precise definition. Deserts may be thought of in terms of biomes in which evaporation exceeds the average precipitation. The rate of evaporation varies with temperature, but desert conditions are likely to develop wherever precipitation is less than 250 mm/yr. Typically, precipitation in deserts is very erratic. Plants and animals are either absent or sparsely distributed, and are adapted to long droughts or to a lack of access to free water.

Geography

An area of very low precipitation, sometimes specified as below 250 mm/yr⁻¹ or where evapotranspiration exceeds precipitation. A desert pavement is a continuous mantle of flat-lying, densely packed, partially overlapping pebbles, typically overlying a soft, silty layer (Quaid (2001) Geology 29, 9). Most desert soils lack clear soil horizons, as the climate is too dry for chemical weathering or humus formation. Leaching occurs only after occasional rain, and is soon reversed by evaporation. Desert varnish is a film of iron oxide or quartz on desert rocks. Silica, slowly dissolved from other minerals, gels together to form a glaze on the rock face. Detrital grains, organic compounds, and pollutants from local environments become entombed in the coating as it forms (Perry (2006) Geology 34, 7).

Philosophy

a Treating persons as they deserve to be treated is a central exercise of justice, proportioning happiness to virtue, or unhappiness to vice. Problems include the distinction between moral and non-moral desert, and the question of whether the variations of treatment have a fundamental place in ethics, or whether they are to be justified, for instance on consequentialist grounds. See also free will, resentment

单词	desert
释义	desert Biology A major terrestrial biome characterized by low rainfall. Hot deserts, such as the Sahara and Kalahari deserts of Africa, have a rainfall of less than 25 cm a year and extremely high daytime temperatures (in some cases up to 50°C). Vegetation is sparse, and desert plants are adapted to conserve water and take advantage of the rain when it falls. The perennials include xerophytic trees and shrubs (see xerophyte) and succulents, such as cacti; many succulents show crassulacean acid metabolism. Annual plants are ephemerals, lying dormant as seeds for most of the year and completing their life cycle in the brief rainy periods. Desert animals are typically nocturnal or active at dawn and dusk, thus avoiding the extreme daytime temperatures. In cold deserts, such as the high plateau of Antarctica, winter temperatures can fall as low as –80°C. Geology and Earth Sciences A term which has no precise definition. Deserts may be thought of in terms of biomes in which evaporation exceeds the average precipitation. The rate of evaporation varies with temperature, but desert conditions are likely to develop wherever precipitation is less than 250 mm/yr. Typically, precipitation in deserts is very erratic. Plants and animals are either absent or sparsely distributed, and are adapted to long droughts or to a lack of access to free water. Geography An area of very low precipitation, sometimes specified as below 250 mm/yr⁻¹ or where evapotranspiration exceeds precipitation. A desert pavement is a continuous mantle of flat-lying, densely packed, partially overlapping pebbles, typically overlying a soft, silty layer (Quaid (2001) Geology 29, 9). Most desert soils lack clear soil horizons, as the climate is too dry for chemical weathering or humus formation. Leaching occurs only after occasional rain, and is soon reversed by evaporation. Desert varnish is a film of iron oxide or quartz on desert rocks. Silica, slowly dissolved from other minerals, gels together to form a glaze on the rock face. Detrital grains, organic compounds, and pollutants from local environments become entombed in the coating as it forms (Perry (2006) Geology 34, 7). Philosophy a Treating persons as they deserve to be treated is a central exercise of justice, proportioning happiness to virtue, or unhappiness to vice. Problems include the distinction between moral and non-moral desert, and the question of whether the variations of treatment have a fundamental place in ethics, or whether they are to be justified, for instance on consequentialist grounds. See also free will, resentment
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