A scheme for ion-based high-harmonic generation from water window to keV x-ray is investigated. He ions with 54.42-eV ionization potential extend the harmonic cutoff energy to 1 keV. The transverse selective-zoning method of quasi-phase-matching is utilized to overcome the severe plasma dispersion in a highly ionized medium. The calculated conversion efficiency reaches about 15% of the perfect phase-matching condition. Wavelength tunability is achieved by incorporating a programmable spatial-light modulator to control the quasi-phase-matching pattern.
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Proc Natl Acad Sci U S A
January 2025
Ewing Marion Kauffman Foundation, Kansas City, MO 64110.
Research that better aligns policy, practice, and research communities is gaining momentum around the world. This includes engaged research strategies that bring partners, and their diverse perspectives and kinds of knowledge, together to shape research agendas with on-the-ground-needs and to create dynamic problem-solving processes. These approaches aim to generate more equitable and effective solutions to societal challenges.
View Article and Find Full Text PDFPLoS One
January 2025
School of Natural Sciences, Macquarie University, North Ryde, NSW, Australia.
The shape characteristics of flow hydrographs hold essential information for understanding, monitoring and assessing changes in flow and flood hydrology at reach and catchment scales. However, the analysis of individual hydrographs is time consuming, making the analysis of hundreds or thousands of them unachievable. A method or protocol is needed to ensure that the datasets being generated, and the metrics produced, have been consistently derived and validated.
View Article and Find Full Text PDFExcavation of underground engineering structures involving deeply buried water-rich soft rocks is generally carried out using the artificial freezing method. A series of undrained uniaxial and triaxial shear and creep tests were conducted on soft rocks under different confining pressures (0, 0.2, 0.
View Article and Find Full Text PDFChem Asian J
December 2024
Department of Chemistry, Indian Institute of Technology Tirupati, Tirupati, A.P 517619, India.
Visible-light absorbing metal-free organic dyes are of increasing demand for various optoelectronic applications because of their great structure-function tunability through chemical means. Several dyes also show huge potential in triplet photosensitization, generating reactive singlet oxygen. Understanding the structure-property relationships of many well-known fluorescein dyes is of paramount importance in designing next-generation energy efficient dyes, which is currently limited.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States.
Generative artificial intelligence (AI) models trained on natural protein sequences have been used to design functional enzymes. However, their ability to predict individual reaction steps in enzyme catalysis remains unclear, limiting the potential use of sequence information for enzyme engineering. In this study, we demonstrated that sequence information can predict the rate of the S2 step of a haloalkane dehalogenase using a generative maximum-entropy (MaxEnt) model.
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