symbol density

См. также в других словарях:

• Density — This article is about mass density. For other uses, see Density (disambiguation). The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ (the Greek letter rho). In some cases… …   Wikipedia

• density — 1. The compactness of a substance; the ratio of mass to unit volume, usually expressed as g/cm3 (kg/m3 in the SI system). 2. The quantity of electricity on a given surface or in a given time per unit of volume. 3. In radiological p …   Medical dictionary

• Levi-Civita symbol — Not to be confused with Levi Civita connection. The Levi Civita symbol, also called the permutation symbol, antisymmetric symbol, or alternating symbol, is a mathematical symbol used in particular in tensor calculus. It is named after the Italian …   Wikipedia

• Number density — In physics, astronomy, and chemistry, number density (symbol: n) is an intensive quantity used to describe the degree of concentration of countable objects (particles, molecules, phonons, galaxies, etc.) in the three dimensional physical space.… …   Wikipedia

• Potential density — The potential density of a fluid parcel at pressure P is the density that the parcel would acquire if adiabatically brought to a reference pressure P {0}, often 1 bar (100 kPa). Whereas density changes with changing pressure, potential density of …   Wikipedia

• Paper density — The paper density of a type of paper or cardboard is the mass of the product per unit of area. Two ways of expressing paper density are commonly used: * Expressed in grams per square metre (g/m²), paper density is also known as… …   Wikipedia

• Sound energy density — The sound energy density or sound density (symbol E or w ) is an adequate measure to describe the sound field at a given point as a sound energy value. The letter lower case w sign w is easily mixed with the sign omega (omega), therefore we… …   Wikipedia

• Schnirelmann density — In additive number theory, the Schnirelmann density of a sequence of numbers is a way to measure how dense the sequence is. It is named after Russian mathematician L.G. Schnirelmann, who was the first to study it. Contents 1 Definition 2… …   Wikipedia

• High-density polyethylene — HDPE has SPI resin ID code 2 High density polyethylene (HDPE) or polyethylene high density (PEHD) is a polyethylene thermoplastic made from petroleum. It takes 1.75 kilograms of petroleum (in terms of energy and raw materials) to make one… …   Wikipedia

• Low-density polyethylene — LDPE has SPI resin ID code 4 Low density polyethylene (LDPE) is a thermoplastic made from petroleum. It was the first grade of polyethylene, produced in 1933 by Imperial Chemical Industries (ICI) using a high pressure process via free radical… …   Wikipedia

• Noise spectral density — In communications, noise spectral density No is the noise power per unit of bandwidth; that is, it is the power spectral density of the noise. It has dimension of power/frequency (see dimensional analysis), whose SI coherent unit is watts per… …   Wikipedia