Jove
Visualize
联系我们
JoVE
x logofacebook logolinkedin logoyoutube logo
关于 JoVE
概览领导团队博客JoVE 帮助中心
作者
出版流程编辑委员会范围与政策同行评审常见问题投稿
图书馆员
用户评价订阅访问资源图书馆顾问委员会常见问题
研究
JoVE JournalMethods CollectionsJoVE Encyclopedia of Experiments存档
教育
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab Manual教师资源中心教师网站
使用条款与条件
隐私政策
政策

相关概念视频

Time and frequency -Domain Interpretation of Phase-lag Control01:21

Time and frequency -Domain Interpretation of Phase-lag Control

92
Phase-lag controllers are widely used in control systems to improve stability and reduce steady-state errors. A dimmer switch controlling the brightness of a light bulb serves as a practical example of phase-lag control, gradually adjusting the bulb's brightness. Mathematically, phase-lag control or low-pass filtering is represented when the factor 'a' is less than 1.
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
92
Time and frequency -Domain Interpretation of Phase-lead Control01:24

Time and frequency -Domain Interpretation of Phase-lead Control

84
Phase-lead controllers are commonly used in various control systems to enhance response speed and stability. Adjusting the brightness on a television screen offers a practical example of phase-lead control. When contrast is enhanced, a phase-lead controller is employed. Mathematically, phase-lead control is identified when the first parameter is smaller than the second.
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...
84
Aliasing01:18

Aliasing

136
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...
136
Linear Approximation in Frequency Domain01:26

Linear Approximation in Frequency Domain

89
Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar.
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
89
IR Frequency Region: X–H Stretching01:24

IR Frequency Region: X–H Stretching

972
In IR spectroscopy, signals produced by the X−H bonds (such as C−H, O−H, or N−H) can be observed in the frequency range of  2700–4000 cm–1. The C−H stretching vibration forms sharp bands in the region 2850–3000 cm–1. The presence of the O−H stretching vibration leads to the forming of an absorption band in the frequency range 3650–3200 cm−1. At the same time, N−H stretching can be confirmed by absorption bands in...
972
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations01:08

IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations

1.0K
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...
1.0K

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序
Same author

Preliminary EEG microstate changes following regulation-focused psychotherapy in adolescents with externalizing disorders.

Asian journal of psychiatry·2026
Same author

Cognitive, Electrophysiological, and Behavioral Presentation of First-Episode Psychosis With or Without Cannabis Exposure.

The American journal of psychiatry·2026
Same author

The first global case of SPINK-1 Gene mutation in adolescent bipolar disorder.

Asian journal of psychiatry·2026
Same author

Cerebral Chromoblastomycosis: A Clinico-Pathological Feature of a Single Case.

Neurology India·2026
Same author

Future of neuromodulation: Biomarker-guided treatment of treatment resistant young-onset mania by precision HD-tDCS.

Asian journal of psychiatry·2026
Same author

An international, double-blind, randomized, placebo-controlled clinical trial of adjunctive trimetazidine to treat people with bipolar depression (the TIDE trial) protocol.

BMC psychiatry·2026

相关实验视频

Updated: Jul 1, 2025

Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization
10:28

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

Published on: July 5, 2016

10.3K

对于相位物体的数字全息图的载波频率估计.

Nishant Goyal, Kedar Khare

    Applied optics
    |March 4, 2024
    PubMed
    概括

    准确的载波边缘频率估计对于离轴数字全息图解调节至关重要. 使用功率光谱中心的新定义提高了准确性,特别是对于相位物体,并提高了噪声强度.

    科学领域:

    • 光学和光子学 在光学和光子学.
    • 数字全息图 (Digital Holography) 是一个数字全息图.
    • 信号处理 信号处理

    背景情况:

    • 离轴数字全息需要精确的载波边缘频率估计,以获得准确的物体波解调.
    • 当前的方法通常依赖于里埃变换中的振幅峰值,对于相位物体来说,这些是不够的.
    • 载体信封的表示是理解全息图解调制忠实性的关键.

    研究的目的:

    • 调查和提出一个更强大的定义,载波边缘频率在数字全息图.
    • 解决现有方法的局限性,特别是对于相位对象.
    • 为了提供一个适用于各种全息图类型的定义,并且对噪声强大.

    主要方法:

    • 使用载体信封表示的数字全息图的分析.
    • 应用曼德尔标准来评估全息画质量.
    • 传统的基于振幅峰值的频率估计与拟议的基于中心点的方法的比较.
    • 使用模拟和实验性的离轴全息图进行验证.

    主要成果:

    • 载波频率的振幅峰值定义被证明对相位物体来说不够.
    • 交叉术语功率频谱的中心点被确定为更合适的载波频率定义.

    更多相关视频

    Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping
    09:43

    Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping

    Published on: March 20, 2017

    9.9K
    Digital Inline Holographic Microscopy DIHM of Weakly-scattering Subjects
    10:16

    Digital Inline Holographic Microscopy DIHM of Weakly-scattering Subjects

    Published on: February 8, 2014

    12.3K

    相关实验视频

    Last Updated: Jul 1, 2025

    Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization
    10:28

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

    Published on: July 5, 2016

    10.3K
    Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping
    09:43

    Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping

    Published on: March 20, 2017

    9.9K
    Digital Inline Holographic Microscopy DIHM of Weakly-scattering Subjects
    10:16

    Digital Inline Holographic Microscopy DIHM of Weakly-scattering Subjects

    Published on: February 8, 2014

    12.3K
  • 这种新的定义证明了对相位对象的统一适用性.
  • 中心式方法提供了对噪声的更好的稳定性,并导致更光滑的包裹表示.
  • 结论:

    • 对于离轴数码全息图,提出了一种基于载体边缘频率的新的,以中心点为基础的定义.
    • 这种方法克服了以前方法的局限性,特别是对于相位对象.
    • 拟议的定义提高了解调精度,噪声弹性和整体波浪表示质量.