Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

¹H NMR: Long-Range Coupling01:27

¹H NMR: Long-Range Coupling

1.7K
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
1.7K
VSEPR Theory and the Effect of Lone Pairs04:01

VSEPR Theory and the Effect of Lone Pairs

41.8K
Effect of Lone Pairs of Electrons on Molecule Geometry
41.8K
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule01:10

Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule

1.1K
In the AX proton spin system, proton A can sense the two spin states of a coupled proton X, resulting in a doublet NMR signal with two peaks of equal (1:1) intensity. When proton A is coupled to two equivalent protons (AX2 spin system), the spin states of each X can be aligned with or against the external field, creating three possible scenarios. This results in a 1:2:1  triplet signal, where the central peak corresponds to the chemical shift of A and is twice as large or intense as the...
1.1K
Spin–Spin Coupling Constant: Overview01:08

Spin–Spin Coupling Constant: Overview

869
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
869
¹H NMR Signal Multiplicity: Splitting Patterns01:13

¹H NMR Signal Multiplicity: Splitting Patterns

4.9K
When protons A and X are coupled, their nuclear spin energy levels are slightly modified. This is because the energy required to excite proton A to a spin state parallel to proton X is slightly different from the energy required for it to become anti-parallel to spin X. Consequently, there are two possible excitation frequencies for A (A1 and A2), depending on the spin state of X, and vice versa. The mutual nature of coupling implies that the difference between frequencies A1 and A2, indicated...
4.9K
¹H NMR: Complex Splitting01:13

¹H NMR: Complex Splitting

1.2K
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
1.2K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

MIS12 Is Required for Kinetochore-Microtubule Attachment in Oocyte Meiosis.

Advanced science (Weinheim, Baden-Wurttemberg, Germany)·2026
Same author

[Chlorella enhances the resistance of wheat to sulfamethoxazole].

Ying yong sheng tai xue bao = The journal of applied ecology·2026
Same author

A gelatin-stabilized nanosilver particle for visual freshness monitoring of braised chicken meat.

NPJ science of food·2026
Same author

Heterometallic incorporation to promote the catalytic activity of polyoxoniobate toward selective oxidation of 5-hydroxymethylfurfural.

Dalton transactions (Cambridge, England : 2003)·2026
Same author

Silver nanoflower SERS substrate incorporating polyoxometalate as an internal standard for selective quantification of cationic dyes.

Talanta·2026
Same author

Decoding Biodiversity in Baiyangdian Lake: A DNA Barcode Reference Library for Aquatic Insects.

Insects·2026

Related Experiment Video

Updated: Jun 2, 2025

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
00:07

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference

Published on: September 5, 2019

8.4K

Optimization analysis for the maximum pairing length of mode-pairing quantum key distribution.

Xing-Yu Zhou, Jia-Rui Hu, Chun-Hui Zhang

    Optics Letters
    |January 16, 2025
    PubMed
    Summary

    Mode-pairing quantum key distribution (MP-QKD) offers practical security by avoiding phase locking. Optimizing the pairing length (l) significantly enhances MP-QKD performance under real-world conditions.

    More Related Videos

    Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
    09:23

    Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

    Published on: May 30, 2014

    14.4K
    Generation and Coherent Control of Pulsed Quantum Frequency Combs
    06:42

    Generation and Coherent Control of Pulsed Quantum Frequency Combs

    Published on: June 8, 2018

    8.9K

    Related Experiment Videos

    Last Updated: Jun 2, 2025

    A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
    00:07

    A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference

    Published on: September 5, 2019

    8.4K
    Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
    09:23

    Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

    Published on: May 30, 2014

    14.4K
    Generation and Coherent Control of Pulsed Quantum Frequency Combs
    06:42

    Generation and Coherent Control of Pulsed Quantum Frequency Combs

    Published on: June 8, 2018

    8.9K

    Area of Science:

    • Quantum Information Science
    • Quantum Cryptography
    • Optical Communication Systems

    Background:

    • Mode-pairing quantum key distribution (MP-QKD) enables secure communication beyond the repeaterless limit without phase locking.
    • Practical MP-QKD implementation is challenged by environmental factors affecting pairing strategy performance.
    • Previous studies lacked thorough analysis of the maximum pairing length (l) determination.

    Purpose of the Study:

    • To analyze the impact of real-world conditions on MP-QKD performance.
    • To quantify systematic misalignment based on fiber fluctuations, laser properties, and detector effects.
    • To determine the optimal maximum pairing length (l) for practical MP-QKD scenarios.

    Main Methods:

    • Investigated the influence of fiber fluctuations, laser linewidth, frequency offset, and after-pulse effects on pairing length (l).
    • Employed the three-intensity decoy-state method to evaluate performance.
    • Accounted for the finite data-size effect in simulations.

    Main Results:

    • Demonstrated that environmental factors critically influence the determination of the maximum pairing length (l).
    • Simulation results show significant performance enhancements are achievable.
    • Optimal selection of the pairing length (l) is crucial for practical MP-QKD.

    Conclusions:

    • Provides a more accurate quantification of systematic misalignment in MP-QKD.
    • Highlights the importance of optimal pairing length selection for practical MP-QKD systems.
    • Offers valuable insights for advancing future MP-QKD experiments and applications.