An experimental and theoretical investigation of rotational energy transfers (RET) of CH involving the B (2)Sigma(-) (v=0, 0=N=5, F) state by collisions with Ar is undertaken, using the photolysis-probe technique. Time-resolved laser-induced fluorescence resulting from an initially prepared fine-structure label is dispersed using a step-scan Fourier transform spectrometer. The spin-resolved RET rate constants are evaluated with the simulation of a kinetic model. The quantum-scattering method is used for the calculation of the fine-structure-resolved cross sections and rate constants in the rotationally inelastic collisions. The theoretical values are generally consistent with our experimental findings, both in the order of magnitude and trend of N and DeltaN dependence. The propensity rules obtained from the experiments are essentially obeyed by theoretical calculations, and are also in accordance with those reported by Kind and Stuhl. The RET rate constants obtained for the v=0 level are smaller than those obtained previously for v=1. The discrepancy in the RET behavior may be caused by an anisotropy difference of the interaction potential resulting from vibrational excitation.
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http://dx.doi.org/10.1002/cphc.200700779 | DOI Listing |
Nat Commun
January 2025
Department of Chemistry, KAIST, Daejeon, Republic of Korea.
Despite its profound significance, the molecular structural changes near the transition state, driven by the vibronic coupling, have remained largely unexplored, leaving a crucial aspect of chemical reactions shrouded in uncertainty. Herein, the dynamical behavior of the reactive flux on the verge of chemical bond breakage was revealed through the spectroscopic characterization of a large amplitude vibrational motion. Highly excited internal rotor states of S methylamine (CHND) report on the structural change as the molecule approaches the transition state, indicating that the quasi-free internal rotation is strongly coupled to the reaction coordinate as their energies near the maximum of the reaction barrier for the N-D chemical bond predissociation.
View Article and Find Full Text PDFACS 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 PDFPLoS One
January 2025
Faculty of Mechanical Engineering & Mechanics, Ningbo University, Ningbo, Zhengjiang, China.
The hydrodynamic performance of a Savonius type turbine (S-type turbine) in wave field is studied. The method of combining numerical simulation with physical experiment is adopted.Based on linear wave theory and turbulence model, Star CCM+numerical simulation software is used for digital modeling, and overlapping grid technology is used for grid modeling.
View Article and Find Full Text PDFBiochemistry
January 2025
Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
CYP105A1 exhibits monooxygenase activity to a wide variety of structurally different substrates with regio- and stereospecificity, making its application range broad. Our previous studies have shown that CYP105A1 wild type and its variants metabolize 12 types of nonsteroidal anti-inflammatory drugs (NSAIDs). In particular, the R84A variant exhibited a high activity against many NSAIDs.
View Article and Find Full Text PDFMater Horiz
January 2025
School of Materials Science and Engineering, Energy Materials and Devices Key Lab of Anhui Province for Photoelectric Conversion, Anhui University, Hefei, Anhui 230601, China.
The triboelectric nanogenerator (TENG) has been proved to be a very promising marine energy harvesting technology. Herein, we have developed a high-performance triboelectric nanogenerator (SD-TENG) with low friction, high durability, swing-induced counter-rotating motion mechanism (SICRMM) and dual potential energy storage and release strategy (DPESRS). The unique counter-rotating motion mechanism enabled SD-TENG to convert the external linear and swing motion energy into rotation motion energy of the inner and outer cylinders, and then converted it into a controllable power output.
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