Examples of using Electron density in English and their translations into Arabic
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Electron density.
It also measured ionosphere electron density and temperature using a Langmuir probe.
Electron density is the measure of the probability of an electron being present at a specific location.
Medical application: Iodine, as an element with high electron density and atomic number, absorbs X-rays well.
The"electron density" is related to this by the average charge state formula_5 of the ions through formula_6, where formula_7 is the number density of electrons. .
The programs used were NHPC(inversion of ionograms to electron density profile), version 4.30, and CARP(computation of average representative profiles), version 2.00.
Electron density calculated for aniline, high density values indicate atom positions, intermediate density values emphasize bonding, low values provide information on a molecule's shape and size.
A study was carried out of the variability of electron density for the bottomside profile of electron concentration, Ne(h), at fixed altitudes over Havana.
Field effects can arise from the electric dipole field of a bond containing an electronegative atom or electron-withdrawing substituent, as well as from an atom or substituent bearing a formal charge.[1] The directionality of a dipole, and concentration of charge, can both define the shape of a molecule'selectric field which will manipulate the localization of electron density toward or away from sites of interest, such as an acidic hydrogen.
Morpholine undergoes most chemical reactions typical for other secondary amines,though the presence of the ether oxygen withdraws electron density from the nitrogen, rendering it less nucleophilic(and less basic) than structurally similar secondary amines such as piperidine.
NeQuick, a quick-run ionospheric electron density model designed for transionosphere propagation applications, was demonstrated and its performance as the Galileo single-frequency ionospheric correction algorithm was evaluated.
Lloyd Viel Berkner(February 1, 1905 in Milwaukee, Wisconsin- June 4, 1967[1] in Washington, D.C.) was an American physicist and engineer. He was one of the inventors of the measuring device that since has become standard at ionospheric stations[2]because it measures the height and electron density of the ionosphere. The data obtained in the worldwide net of such instruments[3] were important for the developing theory of short wave radio propagation to which Berkner himself gave important contributions.
In quantum chemical calculations, the electron density, ρ(r), is a function of the coordinates r, defined so ρ(r)dr is the number of electrons in a small volume dr. For closed-shell molecules, ρ( r){\displaystyle\rho(\mathbf{r})} can be written in terms of a sum of products of basis functions.
The effect is a result of an electric field produced by charge localization in a molecule.[1] This field, which is substituent and conformation dependent,can influence structure and reactivity by manipulating the location of electron density in bonds and/or the overall molecule.[2] The polarization of a molecule through its bonds is a separate phenomenon known as induction.[3] Field effects are relatively weak, and diminish rapidly with distance, but have still been found to alter molecular properties such as acidity.
Spin density is electron density applied to free radicals. It is defined as the total electron density ofelectrons of one spin minus the total electron density of the electrons of the other spin. One of the ways to measure it experimentally is by electron spin resonance,[6] neutron diffraction allows direct mapping of the spin density in 3D-space.
The scientific mission:High-resolution measurements of electrical and magnetic fields in the auroral region, electron density measurements, high- resolution measurements of the electron and ion distribution functions and ultraviolet auroral imaging and atmospheric ultra violet-absorption measurements.
Most molecular modeling softwarepackages allow the user to choose a value for the electron density, often called the IsoValue. Some software[3] also allows for specification of the electron density in terms of percentage of total electrons enclosed. Depending on the IsoValue(typical units are electrons per cubic bohr), or the percentage of total electrons enclosed, the electron density surface can be used to locate atoms, emphasize electron densities associated with chemical bonds, or to indicate overall molecular size and shape.[4].
In compounds with multiple ring systems which are interconnected, this is no longer accurate, so alternating single and double bonds are used. In compounds such as chlorophyll and phenol, some diagrams show a dotted ordashed line to represent the de-localization of areas where the electron density is higher next to the single bonds.[1] Conjugated systems can sometimes represent regions where electromagnetic radiation is absorbed at different wavelengths resulting in compounds appearing coloured. In polymers, these areas are known as chromophores.
For example, in aniline(see image at right). Graphical models,including electron density are a commonly employed tool in chemistry education.[2] Note in the left-most image of aniline, high electron densities are associated with the carbons and nitrogen, but the hydrogens with only one proton in their nuclei, are not visible. This is the reason that X-ray diffraction has a difficult time locating hydrogen positions.
In de-localized or conjugated systems, such as phenol,benzene and compounds such as hemoglobin and chlorophyll, the electron density covers an entire region, i.e., in benzene they are found above and below the planar ring. This is sometimes shown diagrammatically as a series of alternating single and double bonds. In the case of phenol and benzene, a circle inside a hexagon shows the de-localized nature of the compound.
Mulliken population analysis is based on electron densities in molecules and is a way of dividing the density between atoms to give an estimate of atomic charges.
Where P is the density matrix. Electron densities are often rendered in terms of an isosurface(an isodensity surface) with the size and shape of the surface determined by the value of the density chosen, or in terms of a percentage of total electrons enclosed.
Focus electrical FR can also change the location of cell cross section andit will also influence the density of electron and ion around the cell then it will improve the penetration of the cell.
Electrodeless plasma thrusters use the ponderomotive force which acts on any plasma orcharged particle when under the influence of a strong electromagnetic energy density gradient to accelerate both electron and ions of the plasma in the same direction, thereby able to operate without neutralizer.
Analytical electron microscopy at the Natural History Museum has been used for crater measurements, giving a robust size calibration for impacting particle size and a wide range of density and composition.
Fluxes of charged particles, magnetic and electric fields and currents,electron and ion densities, plasma waves and irregularities,electron, ion and neutron temperatures and so on were measured on board and analysed during both calm and turbulent periods in solar-terrestrial relationships.
But mostly electrons stay close to their nucleus as clouds of negative charged density that shift and move with time.
So now we know the density of ALLOWED energy states of mobile electrons and holes.
TPMU will measure the ambient ion and electron temperature, the ion density and composition and the floating potential of the satellite body.
Space environmental exploration andresearch has been carried out on energy electrons, protons, heavy ions and their single particle effects, radiation dosage effects, space thermal plasma, upper atmospheric density and components and solar energy electromagnetic radiation.