関連する実験動画
Updated: Jun 30, 2026

08:48
Stretching Short Sequences of DNA with Constant Force Axial Optical Tweezers
Published on: October 13, 2011
牽引式非弾性衝突による振動刺激
Stuart J Greaves1, Eckart Wrede, Noah T Goldberg
1Laser Chemistry, Spectroscopy and Dynamics Group, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
Nature
|July 4, 2008
まとめ
水素原子とデウテリウム分子の不弾性散乱は予想外にも前方散乱を引き起こし,従来の理論に異議を唱える. これは,新しい"引きずる戦いの"メカニズムを通じて発生し,結合拡張を通して分子振動を刺激します.
科学分野:
- 物理化学 物理化学
- 化学物理 化学物理
- 分子ダイナミクス 分子ダイナミクス
背景:
- 振動不弾性散布は,分子衝突におけるエネルギー転送に不可欠である.
- 従来のモデルは,高衝撃パラメータでの弾性散乱と低衝撃パラメータでの非弾性散乱を予測しています.
- これらのプロセスを理解することは,化学反応とエネルギー状態を制御するための鍵です.
研究 の 目的:
- 基本的なH + D (((2) 衝突システムにおける散乱の振る舞いを調査する.
- 振動不弾性散乱の既存のモデルに挑戦し,改良する.
- このシステムにおける振動刺激に起因する根本的なメカニズムを解明する.
主な方法:
- H + D ((2) の非弾性散射過程の実験観察.
- 衝突ダイナミクスをモデル化するための準古典的な軌道の計算.
- 振動と回転による量子状態変化 (v,j) の分析.
主要な成果:
- 予想に反して,H + D ((2)) の非弾性衝突で支配的な前方散乱が観察されました.
- 振動刺激 (v=0からv'=3) は,圧縮ではなく,主にD-D結合の拡張によって発生します.
- このプロセスは,複合体の形成に吸引力が不十分である"挫折反応"に似ています.
結論:
- H + D ((2) システムは,振動刺激のための新しい"引き寄せ戦"メカニズムを示しています.
- このメカニズムは,H-D-Dの伸縮の外向きの段階の興奮を伴う.
- この発見は,中性-中性衝突における振動エネルギー伝達の新しい経路を示唆しています.
関連する概念動画
Types Of Collisions - I
When two objects come in direct contact with each other, it is called a collision. During a collision, two or more objects exert forces on each other in a relatively short amount of time. A collision can be categorized as either an elastic or inelastic collision. If two or more objects approach each other, collide and then bounce off, moving away from each other with the same relative speed at which they approached each other, the total kinetic energy of the system is said to be conserved. This...
Types of Collisions - II
When two or more objects collide with each other, they can stick together to form one single composite object (after collision). The total mass of the object after the collision is the sum of the masses of the original objects, and it moves with a velocity dictated by the conservation of momentum. Although the system's total momentum remains constant, the kinetic energy decreases, and thus such a collision is an inelastic collision. Most of the collisions between objects in daily life are...
Elastic Collisions: Introduction
An elastic collision is one that conserves both internal kinetic energy and momentum. Internal kinetic energy is the sum of the kinetic energies of the objects in a system. Truly elastic collisions can only be achieved with subatomic particles, such as electrons striking nuclei. Macroscopic collisions can be very nearly, but not quite, elastic, as some kinetic energy is always converted into other forms of energy such as heat transfer due to friction and sound. An example of a nearly...
Elastic Collisions: Case Study
Elastic collision of a system demands conservation of both momentum and kinetic energy. To solve problems involving one-dimensional elastic collisions between two objects, the equations for conservation of momentum and conservation of internal kinetic energy can be used. For the two objects, the sum of momentum before the collision equals the total momentum after the collision. An elastic collision conserves internal kinetic energy, and so the sum of kinetic energies before the collision equals...
IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
A covalently bonded heteronuclear diatomic molecule can be modeled as two vibrating masses connected by a spring. The vibrational frequency of the bond can be expressed using an equation derived from Hooke's law, which describes how the force applied to stretch or compress a spring is proportional to the displacement of the spring. In this case, the atoms behave like masses, and the bond acts like a spring.
According to Hooke's law, the vibrational frequency is directly proportional to the...
According to Hooke's law, the vibrational frequency is directly proportional to the...
Elastic Strain Energy for Shearing Stresses
As discussed in previous lessons, strain energy in a material is the energy stored when it is elastically deformed, a concept crucial in materials science and mechanical engineering. This energy results from the internal work done against the cohesive forces within the material. When a material undergoes shearing stress and corresponding shearing strain, the strain energy density, which is the energy stored per unit volume, is calculated. Within the elastic limit, where the stress is...

