The mesoscale structure of aeolian sand transport determines a variety of natural phenomena studied in planetary and Earth science. We analyze it theoretically beyond the mean-field level, based on the grain-scale transport kinetics and splash statistics. A coarse-grained analytical model is proposed and verified by numerical simulations resolving individual grain trajectories. The predicted height-resolved sand flux and other important characteristics of the aeolian transport layer agree remarkably well with a comprehensive compilation of field and wind-tunnel data, suggesting that the model robustly captures the essential mesoscale physics. By comparing the predicted saturation length with field data for the minimum sand-dune size, we elucidate the importance of intermittent turbulent wind fluctuations for field measurements and reconcile conflicting previous models for this most enigmatic emergent aeolian scale.
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http://dx.doi.org/10.1103/PhysRevE.96.052906 | DOI Listing |
Sci Rep
January 2025
College of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Uneven of filling aggregate gradation may cause transportation problems such as pipe blockage due to segregation and stratification of filling slurry. To study the influence of aggregate gradation on the conveying performance of filler slurry, aggregate gradation experiments were carried out, rheological tests on slurries with coal gangue/aeolian sand ratios (6:4, 5:5 and 4:6) showed that appropriately increasing the proportion of aeolian sand can improve particle gradation. Computational fluid dynamics (CFD) scheme was used to simulate the pipeline transportation characteristics of the slurry under the conditions of three sets each of coal gangue/aeolian sand ratios, slurry concentrations (72%,74% and 76%), and inlet velocities (1.
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January 2025
Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands/Dunhuang Gobi Desert Ecology and Environment Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China.
The Desert oasis ecotone (DOE) protects the oasis from wind and sand intrusion, thereby playing a crucial role in controlling desertification. However, there is limited knowledge about how DOE functions in windproof and sand-fixation. Therefore this study employs a three-dimensional (3D) laser scanner to monitor surface accumulation and erosion, and through field observations, collects data on wind profiles, grain size, and sand transport rates to uncover the role of DOE in aeolian sand protection.
View Article and Find Full Text PDFStabilization of aeolian sand is essential for achieving desertification control, soil and water conservation, and agricultural development in sandy lands. Feldspathic sandstone is a soft clay rock widely found in the Mu Us Sandy Land. The purpose of this study was to ascertain the mechanism for aeolian sand stabilization with feldspathic sandstone from the perspective of particle size distribution.
View Article and Find Full Text PDFPlants (Basel)
October 2024
Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry, Beijing 100091, China.
Fallen leaves and their decomposition directly deposit leaf wax -alkanes into sediments, which can be used to identify local flora. These -alkanes are important for studying past vegetation and climate, but their distribution in sediments must be known. Aeolian sand -alkanes are particularly important for understanding paleoclimates in arid regions, despite the challenges of extraction due to their extremely low abundance.
View Article and Find Full Text PDFAstrobiology
November 2024
Electron Microscopy Core, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida, USA.
A major unknown in the field of planetary protection is the degree to which natural atmospheric processes remove terrestrial microorganisms from robotic and crewed spacecraft that could potentially contaminate Mars (i.e., forward contamination).
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