New particle formation in a tropical marine boundary layer setting was characterized during NASA's Pacific Exploratory Mission-Tropics A program. It represents the clearest demonstration to date of aerosol nucleation and growth being linked to the natural marine sulfur cycle. This conclusion was based on real-time observations of dimethylsulfide, sulfur dioxide, sulfuric acid (gas), hydroxide, ozone, temperature, relative humidity, aerosol size and number distribution, and total aerosol surface area. Classic binary nucleation theory predicts no nucleation under the observed marine boundary layer conditions.
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http://dx.doi.org/10.1126/science.282.5386.89 | DOI Listing |
Neural Netw
January 2025
School of Computer Science, Northwestern Polytechnical University, Xi'an 710129, China.
Synthetic aperture radar (SAR) images are crucial in remote sensing due to their ability to capture high-quality images regardless of environmental conditions. Though it has been studied for years, the following aspects still limit its further improvement. (1) Due to the unique imaging mechanism of SAR images, the influence of speckle noise cannot be avoided.
View Article and Find Full Text PDFJ Pediatr Urol
January 2025
Art Hypospadias, Tunaboylu Sok, Deniz Apt. No.17/3, Bakırköy, 34147, İstanbul, Türkiye; Department of Pediatric Surgery, Division of Pediatric Urology and Andrology, Sechenov First Moscow State Medical University, Moscow, Russian Federation. Electronic address:
J Acoust Soc Am
January 2025
Naval Group Research, 199 av. Pierre-Gilles de Gennes, Ollioulles, 83190 France.
The theory of similitudes provides simple laws by which the response of one system (usually of small size) can be used to predict the response of another system (usually larger). This paper establishes the exact conditions and laws of similitude for the vibrations and acoustic radiation of a panel immersed in a heavy fluid and excited by a turbulent boundary layer. Previous work on vibroacoustic similitude had not considered the problem of a panel radiating in heavy fluid, for which the radiation impedance of the structure must be scaled.
View Article and Find Full Text PDFFront Chem
January 2025
Department of Mathematics and Statistics, Hazara University, Mansehra, Pakistan.
This study investigates the significance of single-walled (SWCNTs) and multi-walled (MWCNTs) carbon nanotubes with a convectional fluid (water) over a vertical cone under the influences of chemical reaction, magnetic field, thermal radiation and saturated porous media. The impact of heat sources is also examined. Based on the flow assumptions, the fundamental flow equations are modeled as partial differential equations (PDEs).
View Article and Find Full Text PDFWe propose an alternative data-free deep learning method using a physics-informed neural network (PINN) to enable more efficient computation of light diffraction from 3D optical metasurfaces, modeling of corresponding polarization effects, and wavefront manipulation. Our model learns only from the governing physics represented by vector Maxwell's equations, Floquet-Bloch boundary conditions, and perfectly matched layers (PML). PINN accurately simulates near-field and far-field responses, and the impact of polarization, meta-atom geometry, and illumination settings on the transmitted light.
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