Under the conditions of room temperature and low pressure, laser-induced fluorescence excitation spectrum of NQ2 in the wavelength region of 440-495 nm was obtained by using optical parameter generator (OPG) and amplifier (OPA) as an excitation source. The OPG/OPA was pumped by a Nd:YAG laser. The peaks of the spectrum are attributed to B2B1 <-- X2A1 transition. The angle-vibration frequency of B2B1 electronic state was calculated. The fluorescence lifetime of B2B1 (0, 9, 0) vibration state under the pressure of 15 Pa was also deduced by measuring the fluorescence time decay spectrum of this state. It is about 49 micros. Fitting the curve the fluorescence radiant lifetime versus pressure, the spontaneous radiant lifetimes tau0 and the rate coefficient kq of non-radiant transition relaxation of B2B1 (0, 9, 0) state are deduced. The results are: tau approximately 55 micros and k(q) = 1.2 x 10(-9) cm3 molecule(-1) s(-1).
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Talanta
January 2025
State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University, Lanzhou, Gansu, 730000, People's Republic of China. Electronic address:
Mercury (II) ions (Hg) are a significant source of heavy metal contamination in groundwater, posing a serious threat to human health and the environment. Therefore, there is an urgent need for the development of a new detection technique with high sensitivity for monitoring Hg in contaminated groundwater. Here, we developed a signal amplifying MOF-based probe (NXS@ZIF-8) for on-site and ultrasensitive dual-channel portable detection of Hg in groundwater.
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January 2025
Professor of Conservative Dentistry, Faculty of Dentistry, Cairo University, Giza, Egypt.
Objectives: To assess the validity of light-induced and laser-induced fluorescence devices compared to the visual-tactile method for detecting secondary caries around resin composite restorations.
Materials And Methods: The study included 20 participants with 30 resin-composite restored teeth. Restorations' margins were examined using three diagnostic methods: the visual-tactile method (FDI criteria), the light-induced fluorescence camera (VistaCam iX), and the laser-induced fluorescence device (DIAGNOdent pen), and the reference was visual inspection after removal of defective restorations.
RSC Adv
January 2025
Nanoscience Program, Institute of Basic and Applied Sciences, Egypt-Japan University of Science and Technology New Borg El-Arab City Alexandria Egypt
We report herein a facile synthesis, characterization, and the electron transfer reaction of a novel light-harvesting material composed of laser-induced graphene (LIG) functionalized with the photoactive 5,10,15,20-tetrakis(4-trimethylammoniophenyl)porphyrin tetra(-toluenesulfonate) dye (TTMAPP). LIG was easily fabricated on the surface of a polyimide sheet using VersaLASER 3.6 (VLS 3.
View Article and Find Full Text PDFTalanta
January 2025
Instituto de Historia (IH-CCHS), CSIC, C/ Albasanz 26-28, 28037, Madrid, Spain. Electronic address:
Analysis of glass-based artworks is important for authentication purposes. In recent years, there have been rapid advancements and improvements in the characterization of glass objects using different analytical approaches. The present study presents an interdisciplinary and multi-analytical authentication approach that provides useful tools and markers to unmask possible imitations, counterfeiting, and forgeries in Cultural Heritage glass beads by comparing the composition of historical and modern glass beads.
View Article and Find Full Text PDFCompr Rev Food Sci Food Saf
January 2025
School of Food and Biological Engineering, Jiangsu University, Zhenjiang, China.
Raman spectroscopy, a nondestructive optical technique that provides detailed chemical information, has attracted growing interest in the food industry. Complementary spectroscopic methods, such as near-infrared (NIR) spectroscopy, nuclear magnetic resonance (NMR), terahertz (THz) spectroscopy, laser-induced breakdown spectroscopy (LIBS), and fluorescence spectroscopy (Flu), enhance Raman spectroscopy's capabilities in various applications. The integration of Raman with these techniques, termed "Raman plus X," has shown significant potential in agri-food analysis.
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