We investigate the fragmentation and isomerization of toluene molecules induced by strong-field ionization with a femtosecond near-infrared laser pulse. Momentum-resolved coincidence time-of-flight ion mass spectrometry is used to determine the relative yield of different ionic products and fragmentation channels as a function of laser intensity. Ultrafast electron diffraction is used to capture the structure of the ions formed on a picosecond time scale by comparing the diffraction signal with theoretical predictions. Through the combination of the two measurements and theory, we are able to determine the main fragmentation channels and to distinguish between ions with identical mass but different structures. In addition, our diffraction measurements show that the independent atom model, which is widely used to analyze electron diffraction patterns, is not a good approximation for diffraction from ions. We show that the diffraction data is in very good agreement with ab initio scattering calculations.
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http://dx.doi.org/10.1039/d0fd00125b | DOI Listing |
J Fluoresc
January 2025
Department of Chemistry, The University of Burdwan, Golapbag, Burdwan, 713104, India.
Nitrogen doped Carbon Quantum Dots (NCQDs) have been synthesized using most economical and easiest hydrothermal process. Here, N-phenyl orthophenylenediamine and citric acid were utilised as a source of nitrogen and carbon for the preparation of NCQDs. The synthesized NCQDs were characterized using experimental techniques like UV - Vis absorption, FT-IR, transmission electron microscopy (TEM), X-ray Diffraction (XRD), EDX, dynamic light scattering (DLS), fluorimeter and time resolved fluorescence spectroscopy.
View Article and Find Full Text PDFJ Microsc
January 2025
Department of Mechanical, Materials and Aerospace Engineering, University of Liverpool, Liverpool, UK.
Electron backscatter diffraction (EBSD) has developed over the last few decades into a valuable crystallographic characterisation method for a wide range of sample types. Despite these advances, issues such as the complexity of sample preparation, relatively slow acquisition, and damage in beam-sensitive samples, still limit the quantity and quality of interpretable data that can be obtained. To mitigate these issues, here we propose a method based on the subsampling of probe positions and subsequent reconstruction of an incomplete data set.
View Article and Find Full Text PDFSensors (Basel)
December 2024
Center for Experimental Chemistry Education of Shandong University, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
In this study, a simple and easy synthesis strategy to realize the modification of AuHgPt nanoalloy materials on the surface of ITO glass at room temperature is presented. Gold nanoparticles as templates were obtained by electrochemical deposition, mercury was introduced as an intermediate to form an amalgam, and then a galvanic replacement reaction was utilized to successfully prepare gold-mercury-platinum (AuHgPt) nanoalloys. The obtained alloys were characterized by scanning electron microscopy, UV-Vis spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction techniques.
View Article and Find Full Text PDFFoods
January 2025
School of Biotechnology, Jiangnan University, Wuxi 214000, China.
The use of nanozymes for electrochemical detection in the food industry is an intriguing area of research. In this study, we synthesized a laccase mimicking the MnO@CeO nanozyme using a simple hydrothermal method, which was characterized by modern analytical methods, such as transmission electron microscope (TEM), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDX), etc. We found that the addition of MnO significantly increased the laccase-like activity by 300% compared to CeO nanorods.
View Article and Find Full Text PDFFoods
December 2024
Instituto de Ciencia y Tecnología de los Alimentos Córdoba (ICYTAC-CONICET), Universidad Nacional de Córdoba, Av. Filloy S/N, Ciudad Universitaria, Córdoba CP 5000, Argentina.
The morphology of wheat starch granules with different damaged starch (DS) content was analyzed using a particle size analyzer and scanning electron microscopy (SEM); the granular structure was studied using FT-IR spectroscopy and X-ray diffraction (XRD); and the granule-water interaction was evaluated by thermogravimetric analysis (TGA) and dynamic vapor sorption (DVS). The increase in the level of DS shifted the population of B-type granules towards larger particle diameters and shifted the population of A-type granules towards smaller particle diameters. The appearance of the surface of the starch-damaged granules was rough and flaky (SEM images).
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