通过低等级的规范化光谱光滑来降低低数STEM-EDX数据的噪声降低
1DENSO IT Laboratory, Research and Development Group, Tokyo, Japan.
概括
这项研究引入了一种新的逐步降噪方法,用于扫描传输电子显微镜-能量分散式X射线 (STEM-EDX) 数据. 该技术提高了对低数量数据的加权主要组件分析 (wPCA) 的适用性,提高了空间分辨率和降低噪音.
科学领域:
- 材料科学 材料科学 材料科学
- 显微镜的使用方法
- 数据分析 数据分析
背景情况:
- 扫描传输电子显微镜-能量分散X射线 (STEM-EDX) 光谱对于材料分析至关重要.
- 权重主要组件分析 (wPCA) 是用于STEM-EDX数据的常见降噪技术.
- 直接的wPCA应用程序在较少的STEM-EDX数据中扎,通常需要空间平均,从而降低分辨率.
研究的目的:
- 开发一种用于低数量的STEM-EDX数据的降噪方法,以保持空间分辨率.
- 为了提高加权主要成分分析 (wPCA) 对于噪音频谱数据集的适用性.
- 改进EDX光谱平滑性和数据低等级性的表征.
主要方法:
- 一种新的逐步降噪方法,结合光谱光滑和wPCA.
- 数字优化,同时描述EDX光谱的平滑性和数据的低等级性.
- 低数量的数据首先被光谱平滑,然后使用wPCA投射到严格跨越的子空间来表示无效.
主要成果:
- 在具有挑战性的低计数STEM-EDX数据上表现出更好的降噪性能.
- 拟议的方法有效地消除了数据,同时保持了空间分辨率.
- 与现有的光谱光滑技术进行比较,显示出优异的性能.
结论:
- 开发的方法增强了对低数量的STEM-EDX数据的wPCA,保持了空间分辨率.
- 这种方法在高分辨率显微镜的传统降噪技术上提供了显著的改进.
- 这些发现对于从噪音频谱数据中准确地表征材料至关重要.
相关概念视频
Downsampling
177
When considering a sampled sequence with zero values between sampling instants, one can replace it by taking every N-th value of the sequence. At these integer multiples of N, the original and sampled sequences coincide. This process, known as decimation, involves extracting every N-th sample from a sequence, thereby creating a more efficient sequence.
The Fourier transform of the decimated sequence reveals a combination of scaled and shifted versions of the original spectrum. This...
The Fourier transform of the decimated sequence reveals a combination of scaled and shifted versions of the original spectrum. This...
177
Upsampling
254
Managing signal sampling rates is essential in digital signal processing to maintain signal integrity. A decimated signal, characterized by a reduced frequency range due to its lower sampling rate, can be upsampled by inserting zeros between each sample. This upsampling process expands the original spectrum and introduces repeated spectral replicas at intervals dictated by the new Nyquist frequency. To refine this zero-inserted sequence, it is passed through a lowpass filter with a cutoff...
254
NMR Spectrometers: Resolution and Error Correction
719
When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
719
Electron Microscope Tomography and Single-particle Reconstruction
2.4K
Transmission electron microscopy (TEM) can be used to determine the 3D structure of biological samples with the help of techniques such as electron microscope tomography and single-particle reconstruction. While single-particle reconstruction can examine macromolecules and macromolecular complexes in vitro conditions only, tomography permits the study of cell components or small cells in vivo.
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
2.4K
¹³C NMR: ¹H–¹³C Decoupling
1.1K
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
1.1K
Quantifying and Rejecting Outliers: The Grubbs Test
1.6K
Sometimes, a data set can have a recorded numerical observation that greatly deviates from the rest of the data. Assuming that the data is normally distributed, a statistical method called the Grubbs test can be used to determine whether the observation is truly an outlier. To perform a two-tailed Grubbs test, first, calculate the absolute difference between the outlier and the mean. Then, calculate the ratio between this difference and the standard deviation of the sample. This...
1.6K


