相关实验视频

Updated: Jan 17, 2026

Quantifying Microorganisms at Low Concentrations Using Digital Holographic Microscopy DHM
07:27

Quantifying Microorganisms at Low Concentrations Using Digital Holographic Microscopy DHM

Published on: November 1, 2017

10.9K

频率脱调分析在多声范围选择性数字全息学中,具有时间异调

Cole Hammond, R Krishna Mohan, Wm Randall Babbitt

    Applied optics
    |September 22, 2025
    PubMed
    概括

    这项研究分析了频率调制连续波 (FMCW) 范围选择性数字全息 (RSDH),当全息集成跨越多个声时. 我们发现,最佳的局部振荡器频率转移可以偏离目标距离,影响全息图的强度和范围分辨率.

    更多相关视频

    Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization10:28

    Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization

    Published on: July 5, 2016

    10.7K
    Rapid Repetition Rate Fluctuation Measurement of Soliton Crystals in a Microresonator07:42

    Rapid Repetition Rate Fluctuation Measurement of Soliton Crystals in a Microresonator

    Published on: December 15, 2021

    3.5K

    相关概念视频

    Double Resonance Techniques: Overview01:12

    Double Resonance Techniques: Overview

    Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
    Spin decoupling is usually achieved by...
    707
    IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations01:08

    IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations

    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...
    1.8K
    Discrete Fourier Transform01:15

    Discrete Fourier Transform

    The Discrete Fourier Transform (DFT) is a fundamental tool in signal processing, extending the discrete-time Fourier transform by evaluating discrete signals at uniformly spaced frequency intervals. This transformation converts a finite sequence of time-domain samples into frequency components, each representing complex sinusoids ordered by frequency. The DFT translates these sequences into the frequency domain, effectively indicating the magnitude and phase of each frequency component present...
    853
    2D NMR: Overview of Heteronuclear Correlation Techniques01:18

    2D NMR: Overview of Heteronuclear Correlation Techniques

    Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other...
    763
    2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)01:19

    2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)

    Heteronuclear single-quantum correlation spectroscopy (HSQC) is a 2D NMR technique that reveals one-bond correlations between hydrogen and a heteronucleus. The HSQC experiment is similar to the heteronuclear correlation experiment (HETCOR) but is more sensitive. In the HSQC spectrum, the proton chemical shift is plotted on the horizontal F2 axis, while the 13C chemical shift is plotted on the vertical F1 axis. The corresponding proton and 13C spectra are also shown. The HSQC contour plot does...
    1.4K
    Aliasing01:18

    Aliasing

    Accurate signal sampling and reconstruction are crucial in various signal-processing applications. A time-domain signal's spectrum can be revealed using its Fourier transform. When this signal is sampled at a specific frequency, it results in multiple scaled replicas of the original spectrum in the frequency domain. The spacing of these replicas is determined by the sampling frequency.
    If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original...
    567