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A type of quasiparticle in physics, [1] a phonon is an excited state in the quantum mechanical quantization of the modes of vibrations for elastic structures of interacting particles. Phonons can be thought of as quantized sound waves, similar to photons as quantized light waves. [2] The study of phonons is an important part of condensed matter ...
A theory that is asymmetric with respect to chiralities is called a chiral theory, while a non-chiral (i.e., parity-symmetric) theory is sometimes called a vector theory. Many pieces of the Standard Model of physics are non-chiral, which is traceable to anomaly cancellation in chiral theories.
The term "chiral" in general is used to describe the object that is non-superposable on its mirror image. [18] In chemistry, chirality usually refers to molecules. Two mirror images of a chiral molecule are called enantiomers or optical isomers. Pairs of enantiomers are often designated as "right-", "left-handed" or, if they have no bias ...
In stereochemistry, a chiral auxiliary is a stereogenic group or unit that is temporarily incorporated into an organic compound in order to control the stereochemical outcome of the synthesis. [ 1 ] [ 2 ] The chirality present in the auxiliary can bias the stereoselectivity of one or more subsequent reactions.
A related notation for crystal structures given a letter and index: A Elements (monatomic), B for AB compounds, C for AB 2 compounds, D for A m B n compounds, (E, F, ..., K More complex compounds), L Alloys, O Organic compounds, S Silicates. Some structure designation share the same space groups. For example, space group 225 is A 1, B 1, and C 1.
Chirality with hands and two enantiomers of a generic amino acid The direction of current flow and induced magnetic flux follow a "handness" relationship. The term chiral / ˈ k aɪ r əl / describes an object, especially a molecule, which has or produces a non-superposable mirror image of itself.
Chiral purity is a measure of the purity of a chiral drug. Other synonyms employed include enantiomeric excess , enantiomer purity, enantiomeric purity, and optical purity. Optical purity is an obsolete term since today most of the chiral purity measurements are done using chromatographic techniques (not based on optical principles).
If the mass in graphene can be controlled, electrons can be confined to massless regions by surrounding them with massive regions, allowing the patterning of quantum dots, wires and other mesoscopic structures. It also produces one-dimensional conductors along the boundary.