Search results
Results from the WOW.Com Content Network
In nuclear physics, a Borromean nucleus is an atomic nucleus comprising three bound components in which any subsystem of two components is unbound. [1] This has the consequence that if one component is removed, the remaining two comprise an unbound resonance , so that the original nucleus is split into three parts.
This implies that each nucleon binds with another one to form a pair, consequently the system cannot be described as independent particles subjected to a common mean field. When the nucleus has an even number of protons and neutrons, each one of them finds a partner. To excite such a system, one must at least use such an energy as to break a pair.
A model of an atomic nucleus showing it as a compact bundle of protons (red) and neutrons (blue), the two types of nucleons.In this diagram, protons and neutrons look like little balls stuck together, but an actual nucleus (as understood by modern nuclear physics) cannot be explained like this, but only by using quantum mechanics.
it is a version without text of the File:Diagram human cell nucleus.svg: Date: 17 jun 2006 (original 27 april 2006) Source: edited with adobe ilustrator: Author: Mariana LadyofHats: Permission (Reusing this file)
Each nucleosome consists of 8 histone protein subunits, around which roughly 147 DNA base pairs are wrapped in 1.67 left-handed turns. Nucleosomes provide about 7-fold initial linear compaction of DNA. [15] The concentration and specific composition of histones used can determine local chromatin structure.
Diagram of the nucleus showing the ribosome-studded outer nuclear membrane, nuclear pores, DNA (complexed as chromatin), and the nucleolus. The nucleus contains nearly all of the cell's DNA , surrounded by a network of fibrous intermediate filaments called the nuclear matrix , and is enveloped in a double membrane called the nuclear envelope .
The isospin and spin quantum numbers of the nucleon have two states each, resulting in four combinations in total. An alpha particle is composed of four nucleons occupying all four combinations, namely, it has two protons (having opposite spin) and two neutrons (also having opposite spin), and its net nuclear spin is zero.
A comprehensive diagram of a human cell nucleus. Date: 27 April 2006: Source: I did it myself with adobe ilustrator using the information found here , ,, and : Author: Mariana Ruiz LadyofHats: Permission (Reusing this file)