We present here the first room-temperature 2D electronic spectroscopy study of energy transfer in the plant light-harvesting complex II, LHCII. Two-dimensional electronic spectroscopy has been used to study energy transfer dynamics in LHCII trimers from the chlorophyll b Qy band to the chlorophyll a Qy band. Observing cross-peak regions corresponding to couplings between different excitonic states reveals partially resolved fine structure at the exciton level that cannot be isolated by pump-probe or linear spectroscopy measurements alone. Global analysis of the data has been performed to identify the pathways and time constants of energy transfer. The measured waiting time (Tw) dependent 2D spectra are found to be composed of 2D decay-associated spectra with three timescales (0.3 ps, 2.3 ps and >20 ps). Direct and multistep cascading pathways from the high-energy chlorophyll b states to the lowest-energy chlorophyll a states have been resolved occurring on time scales of hundreds of femtoseconds to picoseconds.
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Sci Rep
January 2025
Department of Mechanical Engineering, Kerman Branch, Islamic Azad University, Kerman, Iran.
This article introduces an innovative multipurpose system that integrates a solar power plant with a coastal wind farm to generate refrigeration for refinery processes and industrial air conditioning. The system comprises multiple wind turbines, solar power plants, the Kalina cycle to provide partial energy for the absorption refrigeration cycle used in industrial air conditioning, and a compression refrigeration cycle for propane gas liquefaction. An extensive energy and exergy analysis was conducted on the proposed system, considering various thermodynamic parameters such as the solar power plant's energy output, the absorption chiller's cooling load, the electricity generated by the turbines, the wind turbines' power output, and the energy efficiency and exergy of each cycle within the system.
View Article and Find Full Text PDFNat Commun
January 2025
Max Planck Institute of Colloids and Interfaces, Colloid Chemistry Department, Am Mühlenberg 1, 14476, Potsdam, Germany.
Covalent semiconductors of the carbon nitride family are among the most promising systems to realize "artificial photosynthesis", that is exploiting synthetic materials which use sunlight as an energy source to split water into its elements or converting CO into added value chemicals. However, the role of surface interactions and electronic properties on the reaction mechanism remain still elusive. Here, we use in-situ spectroscopic techniques that enable monitoring surface interactions in carbon nitride under artificial photosynthetic conditions.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 130012, Changchun, P. R. China.
High-entropy metal-organic frameworks (HE-MOFs) hold promise as versatile materials, yet current rare examples are confined to low-valence elements in the fourth period, constraining their design and optimization for diverse applications. Here, a novel high-entropy, defect-rich and small-sized (32 nm) UiO-66 (ZrHfCeSnTi HE-UiO-66) has been synthesized for the first time, leveraging increased configurational entropy to achieve high tolerance to doping with diverse metal ions. The lattice distortion of HE-UiO-66 induces high exposure of metal nodes to create coordination unsaturated metal sites with a concentration of 322.
View Article and Find Full Text PDFWaste Manag
January 2025
Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India. Electronic address:
The disposal of waste-printed circuit boards (WPCBs) poses significant environmental and health risks, as they are a major component of e-waste containing hazardous materials. However, WPCBs also contain valuable metallic elements, making them important resources for recycling. To address the dual challenge of hazardous waste management and resource recovery, sustainable approaches for metal extraction from WPCBs are imperative.
View Article and Find Full Text PDFPhys 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.
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