An official website of the United States government
The low-lying energy spectrum of the static-colour-source-anti-source system in a vacuum containing light and strange quarks is computed using lattice QCD for a range of different light quark masses. The resulting levels are described using a simple model Hamiltonian and the parameters in this model are extrapolated to the physical light-quark masses. In this framework, the QCD string tension is found to be sqrt(sigma) = 445(3)_stat (6)_sys MeV.
more »
« less
Light-driven dissipative self-assembly of a peptide hydrogel
Light energy provides an attractive fuel source for energy dissipating systems because of the lack of waste production, wavelength tunability and the potential for spatial and temporal resolution. In this work, we describe a peptide–spiropyran conjugate that assembled into a transient nanofiber hydrogel in the presence of visible light, and dissociated when the light source was removed.
more »
« less
- Award ID(s):
- 2106924
- PAR ID:
- 10332336
- Date Published:
- Journal Name:
- Chemical Communications
- Volume:
- 57
- Issue:
- 100
- ISSN:
- 1359-7345
- Page Range / eLocation ID:
- 13776 to 13779
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Plasmonic photocatalysis is an emerging research field that holds promise for sustainable energy applications, particularly in solar energy conversion. In this study, we focus on the enhancement of broadband light absorption capabilities for plasmonic photocatalyst under white light illumination. By replacing parts of the catalyst with solar absorber, we can significantly improve the total reaction rate under mild heating conditions with less catalyst. Through careful comparison of reaction conditions and systematic optimization of the contributions from photothermal and non-thermal effects, we demonstrate a substantial enhancement in broadband light absorption capacity and overall light effectiveness, paving the way for advanced plasmonic photocatalysts with greater efficiency and practical applicability using solar light as the energy source.more » « less
-
Abstract We report on the preparation of and calibration measurements with a 83 mKr source for the CENNS-10 liquid argon detector. 83 mKr atoms generated in the decay of a 83 Rb source were introduced into the detector via injection into the Ar circulation loop. Scintillation light arising from the 9.4 keV and 32.1 keV conversion electrons in the decay of 83 mKr in the detector volume were then observed. This calibration source allows the characterization of the low-energy response of the CENNS-10 detector and is applicable to other low-energy-threshold detectors. The energy resolution of the detector was measured to be 9% at the total 83 mKr decay energy of 41.5 keV. We performed an analysis to separately calibrate the detector using the two conversion electrons at 9.4 keV and 32.1 keV.more » « less
-
The spatiotemporal regulation of chemical reactivity in biological systems permits a network of metabolic reactions to take place within the same cellular environment. The exquisite control of reactivity is often mediated by out-of-equilibrium structures that remain functional only as long as fuel is present to maintain the higher energy, active state. An important goal in supramolecular chemistry aims to develop functional, energy dissipating systems that approach the sophistication of biological machinery. The challenge is to create strategies that couple the energy consumption needed to promote a molecule to a higher energy, assembled state to a functional property such as catalytic activity. In this work, we demonstrated that the assembly of a spiropyran (SP) dipeptide (1) transiently promoted the proline-catalyzed aldol reaction in water when visible light was present as fuel. The transient catalytic activity emerged from 1 under light illumination due to the photoisomerization of the monomeric, O -protonated (1-MCH + ) merocyanine form to the spiropyran (1-SP) state, which rapidly assembled into nanosheets capable of catalyzing the aldol reaction in water. When the light source was removed, thermal isomerization to the more stable MCH + form caused the nanosheets to dissociate into a catalytically inactive, monomeric state. Under these conditions, the aldol reaction could be repeatedly activated and deactivated by switching the light source on and off.more » « less
-
Abstract A neutrino-like event with an energy of ∼220 PeV was recently detected by the KM3NeT/ARCA telescope. If this neutrino comes from an astrophysical source or from the interaction of an ultrahigh-energy cosmic ray in the intergalactic medium, the ultrahigh-energy gamma rays that are coproduced with the neutrinos will scatter with the extragalactic background light, producing an electromagnetic cascade and resulting in emission at GeV-to-TeV energies. In this Letter, we compute the gamma-ray flux from this neutrino source considering various source distances and strengths of the intergalactic magnetic field (IGMF). We find that the associated gamma-ray emission could be observed by existing imaging air Cherenkov telescopes and air shower gamma-ray observatories, unless the strength of the IGMF isB ≳ 3 × 10−13G or the ultrahigh-energy gamma rays are attenuated inside of the source itself. In the latter case, this source is expected to be radio-loud.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D1CC04971B
