“bar”的概念、定义、翻译、参考文献-科学参考

bar

Physics

A c.g.s. unit of pressure equal to 10⁶ dynes per square centimetre or 10⁵ pascals (approximately 750 mmHg or 0.987 atmosphere). The millibar (100 Pa) is commonly used in meteorology.

Mathematics

The superscript symbol, as in z̄ or x̄, is used to denote the conjugate of a complex number or the mean of a statistical variable.

Astronomy

A unit of pressure, often used to express atmospheric pressures. One bar is equal to 10⁵ pascals, approximately the Earth’s atmospheric pressure at sea level. The millibar (100 Pa) is also frequently used.

Chemistry

A c.g.s. unit of pressure equal to 10⁶ dynes per square centimetre or 10⁵ pascals (approximately 750 mmHg or 0.987 atmosphere). The millibar (100 Pa) is commonly used in meteorology.

Chemical Engineering

A c.g.s. unit of pressure equal to 10⁵ newtons per square metre (N m⁻²) or pascals (Pa). The millibar (mbar) is commonly used by meteorologists (one thousandth of a bar). Standard atmospheric pressure is 1,013 mbar.

Geology and Earth Sciences

1. (b) Unit of pressure approximately equal to one atmosphere (14 lb/in²), and precisely equal to 10⁵ Pa (10⁵ N/m²) in SI units. The pressure of the atmosphere at sea level on average is very approximately one bar, or about 1013 millibars (the bar commonly being divided into one thousand millibars, mb).
2. Geomorphologic term: (a) Low ridge of sand or shingle laid down by marine aggradation in shallow water adjacent to a coastline. There are several varieties: a bay bar joins the two flanks of a bay and may enclose a lagoon; an offshore or barrier bar runs parallel to a coastline and up to 40 km distant. (b) Rocky obstruction across a glaciated valley. See glacial stairway. (c) Lobate river bedform, typically constructed of gravel, often regularly spaced, and forming a riffle or shallow section. (d) Point bar: a low crescentic shoal on the convex side (inside) of a river bend, consisting of material that has been eroded from an outside bend, either opposite or upstream. Point-bar deposits consist of relatively coarse materials, often showing an upstream dip.

Geography

1 On a gently sloping coastline, a submarine accumulation of marine sediment, which may be exposed at low tide. Most bars form where steep, destructive waves break; such bars can be called break-point bars, with crests generally running parallel to the coast. Bay bars extend across an estuary or a bay: ‘it seems likely that [Chesil Beach, UK] began as a bay bar…when the sea level was lower’ (I. West 2007). Some bay bars entirely enclose the inlet, and a lagoon may then form on the landward side; see Roberts and Slater (2007) Holocene 17. Offshore bars, located further out to sea, are thought to result from the breaking of larger waves, which erode the sea bed and throw up material ahead of them to form ridges (Hoefel and Elgar (2003) Science 29).
2 In a glacial trough, such as the Nant Ffrancon of North Wales, a transverse rocky barrier (Embleton (1961) TIBG, 29).
3 Within a river, a deposit of alluvium, dropped where velocity and turbulence are low, and which may form temporary islands. Alternating bars develop as patches of alluvium, often regularly spaced, along opposite sides of a straight channel. Braid bars, roughly diamond shaped, are generally aligned along the channel course; Best et al. (2003) J. Sed. Res. 73, 4 provide ‘a unique [authors’ italics] insight into the process-product relationship of braid-bar’. Point bars form on the inner curves of a meandering river where discharge is low; see Pyrce and Ashmore (2005) Sedimentol. 52, 4.

单词	bar
释义	bar Physics A c.g.s. unit of pressure equal to 10⁶ dynes per square centimetre or 10⁵ pascals (approximately 750 mmHg or 0.987 atmosphere). The millibar (100 Pa) is commonly used in meteorology. Mathematics The superscript symbol, as in z̄ or x̄, is used to denote the conjugate of a complex number or the mean of a statistical variable. Astronomy A unit of pressure, often used to express atmospheric pressures. One bar is equal to 10⁵ pascals, approximately the Earth’s atmospheric pressure at sea level. The millibar (100 Pa) is also frequently used. Chemistry A c.g.s. unit of pressure equal to 10⁶ dynes per square centimetre or 10⁵ pascals (approximately 750 mmHg or 0.987 atmosphere). The millibar (100 Pa) is commonly used in meteorology. Chemical Engineering A c.g.s. unit of pressure equal to 10⁵ newtons per square metre (N m⁻²) or pascals (Pa). The millibar (mbar) is commonly used by meteorologists (one thousandth of a bar). Standard atmospheric pressure is 1,013 mbar. Geology and Earth Sciences 1. (b) Unit of pressure approximately equal to one atmosphere (14 lb/in²), and precisely equal to 10⁵ Pa (10⁵ N/m²) in SI units. The pressure of the atmosphere at sea level on average is very approximately one bar, or about 1013 millibars (the bar commonly being divided into one thousand millibars, mb). 2. Geomorphologic term: (a) Low ridge of sand or shingle laid down by marine aggradation in shallow water adjacent to a coastline. There are several varieties: a bay bar joins the two flanks of a bay and may enclose a lagoon; an offshore or barrier bar runs parallel to a coastline and up to 40 km distant. (b) Rocky obstruction across a glaciated valley. See glacial stairway. (c) Lobate river bedform, typically constructed of gravel, often regularly spaced, and forming a riffle or shallow section. (d) Point bar: a low crescentic shoal on the convex side (inside) of a river bend, consisting of material that has been eroded from an outside bend, either opposite or upstream. Point-bar deposits consist of relatively coarse materials, often showing an upstream dip. Geography 1 On a gently sloping coastline, a submarine accumulation of marine sediment, which may be exposed at low tide. Most bars form where steep, destructive waves break; such bars can be called break-point bars, with crests generally running parallel to the coast. Bay bars extend across an estuary or a bay: ‘it seems likely that [Chesil Beach, UK] began as a bay bar…when the sea level was lower’ (I. West 2007). Some bay bars entirely enclose the inlet, and a lagoon may then form on the landward side; see Roberts and Slater (2007) Holocene 17. Offshore bars, located further out to sea, are thought to result from the breaking of larger waves, which erode the sea bed and throw up material ahead of them to form ridges (Hoefel and Elgar (2003) Science 29). 2 In a glacial trough, such as the Nant Ffrancon of North Wales, a transverse rocky barrier (Embleton (1961) TIBG, 29). 3 Within a river, a deposit of alluvium, dropped where velocity and turbulence are low, and which may form temporary islands. Alternating bars develop as patches of alluvium, often regularly spaced, along opposite sides of a straight channel. Braid bars, roughly diamond shaped, are generally aligned along the channel course; Best et al. (2003) J. Sed. Res. 73, 4 provide ‘a unique [authors’ italics] insight into the process-product relationship of braid-bar’. Point bars form on the inner curves of a meandering river where discharge is low; see Pyrce and Ashmore (2005) Sedimentol. 52, 4.
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