相关实验视频
Updated: Jun 17, 2025

10:59
Analysis of SEC-SAXS data via EFA deconvolution and Scatter
Published on: January 28, 2021
9.0K
在对齐系统中圆形SAXS模式的演变.
N Sanjeeva Murthy1, David T Grubb2
1Rutgers University, New Brunswick, New JerseyUSA.
概括
微角散射揭示了聚合物和液晶中的圆形图案,这是由于不完美的层状结构造成的. 这种分析提供了对微观结构参数的见解,例如链滑和堆方向.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物物理 聚合物物理
- 液晶是一种液晶.
背景情况:
- 半晶体聚合物和液晶表现出复杂的散射模式.
- 微角X射线和中子散射 (SAXS和SANS) 揭示了结构细节.
- 有序的组件和无关的结构有助于散射配置文件.
研究的目的:
- 分析在不完美排序的状系统中观察到的明显的SAXS模式.
- 模拟从状堆中形成圆散射轨迹的过程.
- 从散射数据中提取微结构参数.
主要方法:
- 分析了四个不同的SAXS模式:两点"香",四点",眉毛"和"蝶".
- 采用链滑,堆旋转和层间剪切的板状堆的建模.
- 将中央扩散散射 (CDS) 分离为同位素和定向元件.
- 使用圆坐标调配散射数据.
主要成果:
- 观察到的SAXS模式显示圆的强度轮,而不是圆形或线性.
- 建模证实,链滑和堆旋转/剪切产生这些圆形图案.
- 变形的CDS形成了赤道条纹,形状如圆,钻石或螺旋.
- 分析结果显示了叶片间距,叶片间剪切角 (α),链滑角 (φ) 和堆大小分布.
结论:
- 圆散射分析提供了一种强大的方法来表征不完美的叶片结构.
- SAXS和SANS与建模相结合,可以快速改进微观结构参数.
- 该研究提供了一种定量方法,以了解聚合物和液晶变形.
相关概念视频
Oscillations about an Equilibrium Position
5.4K
Stability is an important concept in oscillation. If an equilibrium point is stable, a slight disturbance of an object that is initially at the stable equilibrium point will cause the object to oscillate around that point. For an unstable equilibrium point, if the object is disturbed slightly, it will not return to the equilibrium point. There are three conditions for equilibrium points—stable, unstable, and half-stable. A half-stable equilibrium point is also unstable, but is named so...
5.4K
Eccentric Axial Loading in a Plane of Symmetry
176
Eccentric axial loading occurs when an axial load is applied away from the centroidal axis of a structural member. This scenario is common in engineering, where structural elements may not be directly aligned due to various design or functional requirements.
176
Gauss's Law: Planar Symmetry
7.9K
A planar symmetry of charge density is obtained when charges are uniformly spread over a large flat surface. In planar symmetry, all points in a plane parallel to the plane of charge are identical with respect to the charges. Suppose the plane of the charge distribution is the xy-plane, and the electric field at a space point P with coordinates (x, y, z) is to be determined. Since the charge density is the same at all (x, y) - coordinates in the z = 0 plane, by symmetry, the electric field at P...
7.9K
Kepler's First Law of Planetary Motion
4.0K
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. He formulated his first two laws based on the observations of his forebears, Nikolaus Copernicus and Tycho Brahe.
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
4.0K
Gauss's Law: Spherical Symmetry
7.4K
A charge distribution has spherical symmetry if the density of charge depends only on the distance from a point in space and not on the direction. In other words, if the system is rotated, it doesn't look different. For instance, if a sphere of radius R is uniformly charged with charge density ρ0, then the distribution has spherical symmetry. On the other hand, if a sphere of radius R is charged so that the top half of the sphere has a uniform charge density ρ1 and the bottom half...
7.4K
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
954
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single...
954

