We used relaxation-assisted two-dimensional infrared spectroscopy to study the temperature dependence (10-295 K) of end-to-end energy transport across end-decorated PEG oligomers of various chain lengths. The excess energy was introduced by exciting the azido end-group stretching mode at 2100 cm (tag); the transport was recorded by observing the asymmetric C═O stretching mode of the succinimide ester end group at 1740 cm. The overall transport involves diffusive steps at the end groups and a ballistic step through the PEG chain. We found that at lower temperatures the through-chain energy transport became faster, while the end-group diffusive transport time and the tag lifetime increase. The modeling of the transport using a quantum Liouville equation linked the observations to the reduction of decoherence rate and an increase of the mean-free-path for the vibrational wavepacket. The energy transport at the end groups slowed down at low temperatures due to the decreased number and efficiency of the anharmonic energy redistribution pathways.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.jpclett.0c01273 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Experimental and kinetic modeling study of oxidative degradation of benzene and phenol in supercritical water.
J Environ Manage
January 2025
Shaanxi Key Laboratory of New Transportation Energy and Automotive Energy Saving, School of Energy and Electrical Engineering, Chang'an University, Xi'an, Shaanxi, 710064, PR China.
Benzene and phenol are representative aromatic compounds existing commonly in wastewater. The kinetics of oxidative degradation of benzene and phenol in supercritical water have been investigated in a flow reactor at 823 K and 250 atm, with the excess oxygen ratio ranging from 0.5 to 2.
View Article and Find Full Text PDFPotential bacterial resources for bioremediation of organochlorine pesticides and flame retardants recognized from forest soil across China.
J Hazard Mater
December 2024
The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong 510006, PR China.
Microbe-mediated remediation becomes a desire method for removal of persistent organic pollutants (POPs) due to its eco-friendly and sustainable nature. The improvement of practical feasibility requires constructing comprehensive species pool, while it is still limited by the rapid recognition of potential bacterial resources from environment. Here, based on the relative abundances of bacterial OTUs and pollutant concentrations, we established indexes to assess their tolerance to organochlorine pesticides (OCPs) and flame retardants (FRs) that are atmospheric transported and naturally accumulated in forest soil via forest filter effect.
View Article and Find Full Text PDFMatched Guiding and Controlled Injection in Dark-Current-Free, 10-GeV-Class, Channel-Guided Laser-Plasma Accelerators.
Phys Rev Lett
December 2024
Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
We measure the high-intensity laser propagation throughout meter-scale, channel-guided laser-plasma accelerators by adjusting the length of the plasma channel on a shot-by-shot basis, showing high-quality guiding of 500 TW laser pulses over 30 cm in a hydrogen plasma of density n_{0}≈1×10^{17} cm^{-3}. We observed transverse energy transport of higher-order modes in the first ≈12 cm of the plasma channel, followed by quasimatched propagation, and the gradual, dark-current-free depletion of laser energy to the wake. We quantify the laser-to-wake transfer efficiency limitations of currently available petawatt-class lasers and demonstrate via simulation how control over the laser mode can significantly improve beam parameters.
View Article and Find Full Text PDFOn-Chip Elastic Wave Manipulations Based on Synthetic Dimension.
Phys Rev Lett
December 2024
Key Laboratory of Materials Physics of Ministry of Education, School of Physics, Zhengzhou University, Zhengzhou 450001, China.
Manipulating elastic waves in lower-dimensional mechanical metamaterials has attracted much attention since it lays the foundation for the design of various elastic functional devices, especially for on-chip size. However, due to the experimental challenges, it is very difficult to control elastic waves in higher dimensions. In this Letter, we introduce an extra structural parameter to synthesize and investigate the on-chip Weyl physics in silicon-on-insulator system.
View Article and Find Full Text PDFEnhancing Carbon Monoxide Tolerance in Low-Temperature PEM Fuel Cells through Carbon Nitride Surface Modification.
ACS Appl Mater Interfaces
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Low-temperature proton exchange membrane fuel cells (PEMFCs) reuqire highly pure hydrogen gas due to their extreme sensitivity to carbon monoxide (CO) contamination, which poses a challenge for using cost-effective reformed hydrogen sources. To address this issue, we have developed a surface modification strategy by applying a 0.5-0.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!