Combined analysis of helium (584 angstroms) airglow and the atmospheric occultations of the star delta Scorpii imply a vertical mixing parameter in Saturn's upper atmosphere of K (eddy diffusion coefficient) approximately 8 x 10(7) square centimeters per second, an order of magnitude more vigorous than mixing in Jupiter's upper atmosphere. Atmospheric H(2) band absorption of starlight yields a preliminary temperature of 400 K in the exosphere and a temperature near the homopause of approximately 200 K. The energy source for the mid-latitude H(2) band emission still remains a puzzle. Certain auroral emissions can be fully explained in terms of electron impact on H(2), and auroral morphology suggests a link between the aurora and the Saturn kilometric radiation. Absolute optical depths have been determined for the entire C ring andparts of the A and B rings. A new eccentric ringlet has been detected in the C ring. The extreme ultraviolet reflectance of the rings is fairly uniform at 3.5 to 5 percent. Collisions may control the distribution of H in Titan's H torus, which has a total vertical extent of approximately 14 Saturn radii normal to the orbit plane.
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http://dx.doi.org/10.1126/science.215.4532.548 | DOI Listing |
J Phys Chem A
January 2025
School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China.
With the advancement of extreme ultraviolet (EUV) lithography technology, the demand for high-performance EUV photoresists has surged. Traditional photoresists struggle to meet the stringent requirements for increasingly smaller feature sizes in semiconductor manufacturing. Among emerging candidates, tin-based materials, particularly Sn-oxo photoresists, have shown promise due to their superior EUV light absorption properties.
View Article and Find Full Text PDFNano Lett
January 2025
Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300350, China.
Rare-earth (RE) metals are known as industrial vitamins and show significant regulatory effects in many fields. In this work, we first demonstrated that the vitamin effect of RE metals can also be applied to extreme ultraviolet (EUV) lithography. Using a SnRE oxo cluster as the universal platform, different individual RE metal ions were successfully doped to obtain a series of isomorphic heterometallic clusters (RE = Y, Sm, Eu, Ho, Er).
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Mechanical Engineering Department, Universidad Carlos III de Madrid, 28911 Leganés, Spain.
The degradation of rubber materials under environmental and mechanical stress presents a significant challenge, particularly due to UV (ultraviolet light) exposure, which severely impacts the material's physical properties. This study aims to enhance the UV stability and longevity of rubber by evaluating the performance of modified polyurethane and silicone coatings as protective stabilizers. Natural rubber-styrene-butadiene rubber (NR-SBR), known for its exceptional mechanical properties, was selected as the base material.
View Article and Find Full Text PDFSmall
January 2025
Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea.
Extreme ultraviolet (EUV) lithography has enabled significant reductions in device dimensions but is often limited by capillary force-driven pattern collapse in conventional wet processes. Recent dry-development approaches, while promising, frequently require toxic etchants or specialized equipment, limiting their broader applicability and highlighting the need for more sustainable, cost-effective alternatives. In this study, highly reactive, etchant-free dry-developable EUV photoresists using N-heterocyclic carbene (NHC)-based metal-ligand complexes, achieving half-saturation at EUV doses of 8.
View Article and Find Full Text PDFMater Horiz
January 2025
College of Material and Chemical Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450002, China.
A new photopolymerizable organic-inorganic (O-I) hybrid sol-gel material, AUP@SiO-184, has been synthesized and utilized as a gate dielectric in flexible organic thin-film transistors (OTFTs). The previously reported three-arm alkoxy-functionalized silane amphiphilic polymer has yielded stable O-I hybrid materials comprising uniformly dispersed nanoparticles in the sol state. In this study, a photosensitizer was introduced, facilitating curing effects under ultraviolet light.
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