サインイン

第7章

核磁気共鳴の原理

核磁気共鳴(NMR):概要
核磁気共鳴(NMR):概要
Nuclear magnetic resonance (NMR) is a phenomenon exhibited by certain nuclei that can absorb characteristic radio frequency radiation under certain ...
原子核:核スピン
原子核:核スピン
All atomic particles possess an intrinsic angular momentum, or 'spin'. Electrons, protons, and neutrons each have a spin value of ½, although ...
原子核:核磁気モーメント
原子核:核磁気モーメント
All atomic nuclei are positively charged. When they have a nonzero spin, they behave like rotating charges. As a consequence of their charge and spin, ...
原子核:核スピン状態の概要
原子核:核スピン状態の概要
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the ...
原子核:核スピン状態の集団分布
原子核:核スピン状態の集団分布
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy ...
原子核:ラーマー歳差運動周波数
原子核:ラーマー歳差運動周波数
The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) ...
原子核:磁気共鳴
原子核:磁気共鳴
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external ...
原子核:核緩和過程
原子核:核緩和過程
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin ...
原子核:核緩和の種類
原子核:核緩和の種類
Relaxation in NMR systems is a first-order exponential decay and can occur by either spin–lattice or spin–spin mechanisms. Spin–lattice ...
NMR分光計:概要
NMR分光計:概要
NMR spectrometers consist of a strong magnet, a radiofrequency transmitter, and a detector attached to a computer console for recording spectra of samples ...
NMR分光計:高周波パルスとパルスシーケンス
NMR分光計:高周波パルスとパルスシーケンス
A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a ...
NMR分光計:分解能と誤差補正
NMR分光計:分解能と誤差補正
When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction ...
原子核の反磁性シールド:局所反磁性電流
原子核の反磁性シールド:局所反磁性電流
An applied magnetic field causes the electrons present in the molecule to circulate, setting up a local diamagnetic current within the molecule. The local ...
JoVE Logo

個人情報保護方針

利用規約

一般データ保護規則

研究

教育

JoVEについて

Copyright © 2023 MyJoVE Corporation. All rights reserved