Surface oxidation irreversibly removes both oxygen and hydrogen from the martian atmosphere at a rate of 10(8) to 10(11) per square centimeter per second. This rate corresponds to a net loss of 10(25) to 10(28) per square centimeter (10(2) to 10(5) grams per square centimeter) of H(2)O, if it is assumed that the loss rate is uniform over geologic time. Heretofore, exospheric escape was considered to be the principal irreversible sink for H(2)O, but the loss rate was estimated to be only 10(8) per square centimeter per second. It is possible that surface oxidation may have had a minor effect on the supply of H(2)O in the regolith and polar caps.
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http://dx.doi.org/10.1126/science.192.4235.138 | DOI Listing |
Sci Adv
January 2025
Fujian Key Laboratory of Semiconductor Materials and Applications, CI Center for OSED, Department of Physics, Xiamen University, Xiamen 361005, P. R. China.
The utilization of low-dimensional perovskites (LDPs) as interlayers on three-dimensional (3D) perovskites has been regarded as an efficient strategy to enhance the performance of perovskite solar cells. Yet, the formation mechanism of LDPs and their impacts on the device performance remain elusive. Herein, we use dimensional engineering to facilitate the controllable growth of 1D and 2D structures on 3D perovskites.
View Article and Find Full Text PDFSci Robot
January 2025
Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
Aerial insects are exceptionally agile and precise owing to their small size and fast neuromotor control. They perform impressive acrobatic maneuvers when evading predators, recovering from wind gust, or landing on moving objects. Flapping-wing propulsion is advantageous for flight agility because it can generate large changes in instantaneous forces and torques.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Chemical Engineering, Kansas State University, Manhattan, KS, USA.
Protonic ceramic electrochemical cells (PCECs) can operate at intermediate temperatures (450° to 600°C) for power generation and hydrogen production. However, the operating temperature is still too high to revolutionize ceramic electrochemical cell technology. Lowering the operating temperature to <450°C will enable a wider material choice and reduce system costs.
View Article and Find Full Text PDFScience
January 2025
Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, School of Materials Science and Engineering, Peking University, Beijing, China.
One of the primary challenges in commercializing perovskite solar cells (PSCs) is achieving both high power conversion efficiency (PCE) and sufficient stability. We integrate wafer-scale continuous monolayer MoS buffers at the top and bottom of a perovskite layer through a transfer process. These films physically block ion migration of perovskite into carrier transport layers and chemically stabilize the formamidinium lead iodide phase through strong coordination interaction.
View Article and Find Full Text PDFMed J Islam Repub Iran
September 2024
Burn Research Center, Shahid Motahari Hospital, Iran University of Medical Sciences, Tehran, Iran.
Background: Treatment of hypertrophic burn scars is challenging. Intralesional injection of corticosteroids has been the first line of treatment. Triamcinolone Acetonide (TA) and Bleomycin (BLE) are standard therapeutic options.
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