Large-scale atmospheric circulations inferred from manually labeled dunes may be biased due to limitations in data quantity and regional representativeness. This study developed a post-processing workflow based on the adjacent dune similarity and applied it to mask region-based convolutional neural network (Mask R-CNN), extracting morphological metrics for 206,972 barchans (5113 with dynamics) in the Taklamakan Desert. Our results show that dune-derived near-surface wind circulations generally align with reanalysis data but exhibit significant deviations near mountain ranges due to topographic effects. Compared to static dune morphologies, multi-temporal analysis of dune migration provides a more reliable reference for identifying dominant sand-transporting winds by minimizing the effects of local wind variability, thus serving as a robust indicator for reconstructing long-term wind regimes. Dune dynamic patterns in the desert interior regions are more complex compared to those in the marginal areas. When using interior dunes to predict local circulation, it is essential to account for the influences of local topography and dune morphology variations. After correcting for the dune-size effect, the sand flux estimated from our dune celerity dataset demonstrates comparable magnitude and spatial distribution to reanalysis predictions. Notably, in areas with high barchan density, dune-based sand flux estimation reveals fine-scale variations in aeolian sediment transport.

Fluvial-aeolian interactions are integral to the evolution of desert landscapes, yet the associated processes and sediment sources remain an area of active investigation. Recent studies highlight the potential of grain shape characteristics as indicators of sediment transport history and provenance. The Horqin Sandy Land (HQ) in northeastern China is a dunefield characterized by intensive fluvial-aeolian interactions. However, surface processes and its provenance connection with the upwind Hunshandake Sandy Land (HSDK) require further clarification. The grain size and shape of fluvial sediments and dune sand samples from the HQ and surrounding regions were analyzed to elucidate transport processes and sand provenance. The grain shape of most river sediments significantly differs from that of aeolian sands in the HQ, except for sediments from the Xilamulun River (XLML), which originate in the HSDK and exhibit grain shape characteristics similar to HQ aeolian sands. Approximately 80 % of the fine sand transported by the XLML is derived from the HSDK, resulting in high sphericity of finer sand in the western HQ. Aeolian sands in the HQ exhibit pronounced spatial heterogeneity in grain size and shape parameters, reflecting strong fluvial-aeolian interactions. Wind-driven sorting and abrasion exert dominant control on sediment patterns in the western and central HQ, while their impacts are diminished in the eastern HQ due to a barrier effect of rivers and increased sediments influx from the Yanshan Mountains. These findings highlight the complexity of fluvial-aeolian sediment dynamics. Moreover, they demonstrate that grain-shape analysis-characterized by low cost and high efficiency-can effectively resolve sediment provenance and surface processes even when their geochemical signatures are similar, underscoring its unique value as a tracer in desert environments.

Stable continental regions (SCRs) are characterized by low strain rates and long earthquake recurrence intervals, but the patterns and drivers of their seismicity remain debated. This study investigates the rupture history of the Liuyuan fault in the low-strain Beishan region of China to determine whether SCR earthquakes are regular, clustered, or random. We integrate paleoseismic trenching, IRSL and cosmogenic 10Be dating of trench units and rockfalls, and microstructural analyses of fault-zone materials. Our results reveal two distinct earthquake clusters at 65.5-46.2 ka and 8.8-4.6 ka, possibly separated by a long period of quiescence, which remains unconfirmed due to a sedimentary record gap. The late Pleistocene cluster is independently corroborated by cosmogenic 10Be ages of rockfalls, which cluster at 46-48 ka and overlap within uncertainty. Microstructural evidence, including multiple generations of quartz veins and abundant phyllosilicates, points to a fluid-driven, fault-valve mechanism. We propose that episodic increases in deep-sourced fluid pressure, facilitated by a steep fault geometry within a transpressional regime, trigger these rupture clusters. A comparison with other SCRs globally suggests that this clustered behavior, observed in some intraplate settings, may be controlled by key factors: a weakened lithosphere that localizes strain and transient stress perturbations from fluid migration or surface processes. These findings challenge the assumption of time-independent seismicity in some SCRs and have significant implications for seismic hazard assessment, particularly for critical infrastructure in low-strain environments like the Beishan region, a proposed site for high-level radioactive waste disposal.

Dune dynamics are fundamentally governed by interactions between airflow and sand grains, modulated by climate and human activities. However, their multi-decadal patterns remain insufficiently quantified largely due to limited data availability. Here we investigate the morphodynamics of 163 barchans across 11 sites in the Taklamakan Desert, the largest sand sea in China. By integrating historical CORONA images (pre-1980s) with contemporary remote sensing data, we extend dune migration records to over half a century. We find that dune celerity in high wind-energy regions, such as the eastern desert, decreased from the 1960s-1980s to the 1980s-2000s, whereas initially slow-moving dunes in the northern desert show minimal temporal change; thereafter, dune celerity across all regions remained relatively stable with minimal temporal changes through the 2020s. These patterns are consistent with regional wind weakening since the mid-1970s and with stabilized wind intensity after the 1990s. Wind conditions and dune size dominate multi-decadal dune dynamic patterns, while other boundary conditions, such as vegetation, can allow dune fields near expanding oases to sustain low celerity over the long term by reducing near-surface wind speed. Although ERA5-Land-derived sand fluxes generally match observed dune behaviors, region-specific calibration is required for better accuracy. Because global reanalysis products such as ERA5 provide spatially and temporally consistent wind data and are often the only available source in remote and data-scarce dune fields, we propose that integrating dune celerity with geometric investigations offers a promising pathway to refine ERA5-based dune turnover-time estimates, particularly in regions where barchans are present.

Deserts' paleoenvironmental records not only reveal environmental changes during geological periods but also provide a scientific basis for addressing and predicting their response pathways to the ongoing global warming. Nevertheless, comparative studies examining the variability of dune activity in the deserts of northern China under different warming periods triggered by natural and anthropogenic factors remain scarce. Leveraging the Coupled Model Intercomparison Project Phase 6 multimodel ensemble, this study investigates the spatial patterns and underlying climatic drivers of dune activity in the deserts of northern China across distinct climatic epochs: the mid-Holocene (MH) and scenarios under three different future Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, and SSP5-8.5). The results reveal different spatial heterogeneity of dune activity in the deserts of northern China during MH and future scenarios. During the MH, dune activity decreased significantly in the eastern deserts while intensifying in the west. However, under the future scenarios, this trend would be reversed, with enhanced dune activity in the east and diminished activity in the west. The spatial disparities are directly attributable to changes in surface effective moisture and near-surface wind speed induced by large-scale atmospheric circulations. In the eastern sandy lands, a stronger East Asian Summer Monsoon increased surface moisture and limited aeolian processes during MH, while higher evaporation and stronger near-surface wind in the east would intensify dune activity under future scenarios. In the western sand seas, reduced precipitation due to weaker westerlies enhanced dune activity during MH, while increased precipitation and reduced near-surface wind speeds under future scenarios would lead to decrease in dune activity.

The Western Junggar Mountains, Junggar Basin, and East Junggar ranges lie between the Tian Shan and Altai Mountains in Central Asia. Cenozoic northward subduction of the Indo Plate beneath Eurasia has reactivated these features through intense crustal shortening, driving modern topographic growth in the region. The manner in which the strain between the Tian Shan and Altai mountains is transmitted through the Western Junggar Mountains has remained unclear. The Western Junggar Fault System comprises the East Tacheng, Tuoli, and Daerbute sinistral strike‐slip faults. This study focused on the Tuoli fault. Based on the geometry and continuity of the fault traces, this fault can be divided into northern and southern branches, forming two fault segments. Paleoseismic observations have revealed two or three events since 15.4 ± 7.7 ka. Paleoseismic exposure observations and fault lengths show that the most recent event (Mw 7.1 or 7.6) ruptured the northern branch and occurred 1.5 ∼ 4.0 ka. Based on the offset geomorphological features and abandonment ages of alluvial or fluvial surfaces, the average late Pleistocene slip rate along the southern branch is 1.4 ± 0.2 mm/yr and is 0.4 ± 0.1 mm/yr along the northern branch. Slip rates derived from geological observations are consistent with those (1.7 mm/yr) obtained from the block rotation model. This consistency indicates that the Tuoli fault, along with the two other left‐lateral strike‐slip faults in the Western Junggar Mountains, forms a bookshelf structure that accommodates crustal shortening between the Tian Shan and Altai Mountains via clockwise block rotation.

Grassland soils in alpine regions of the Qinghai-Tibetan Plateau (QTP) constitute a crucial component of the QTP ecosystem. Understanding their formation requires accurate chronologies and insights into key pedogenic processes. This study applied multi-grain (MG) and single-grain (SG) post-infrared infrared stimulated luminescence (pIRIR) dating to alpine grassland soils around the Gonghe Basin in the northeastern (NE) QTP to gain new insights into their ages and pedogenic processes. In addition, C-14 dating was performed on soil organic matter, with the resulting C-14 ages compared with optical ages to evaluate their reliability for soil age determination. pIRIR dating showed that bioturbation-induced soil reworking is common in alpine grassland soils. SG pIRIR dating allows more accurate soil age estimation by effectively identifying grains associated with original deposition and pedoturbation, while C-14 dating yields underestimated ages due to younger carbon contamination. We proposed an SG pIRIR-based approach that can be applied to alpine grassland soils to constrain their ages and quantify bioturbation. Combined with a synthesis of regional alpine loess and palaeosol/soil chronologies and a comparison with regional climatic records, the influence of climate on alpine soil pedogenesis and bioturbation was explored. Our results showed that pedogenesis in the studied profiles started at similar to 11-5 ka, following an aeolian dust aggradation pedogenic mode. The intensity of soil mixing decreases with depth, with the most intensive mixing occurring in a near-surface zone of tens of centimetres depth. Integrating SG dating results with a new conceptual model, we for the first time estimated the recent and past downward soil mixing rates and the timing of intensified bioturbation for alpine soils on the QTP. Chronological synthesis revealed that alpine soil development on the NE-QTP was most pronounced since similar to 6 ka. Effective moisture is a key factor that affects both soil development and bioturbation intensity in alpine grassland soils.

In compressional active orogenic belts, crustal deformation is accommodated by strike-slip faults and thrust faults. Studying the fault interactions of different types of active faults is important for understanding mountain building and seismogenic characteristics. This study uses field mapping, high-resolution digital elevation models, and in situ cosmogenic nuclides to present data from active thrusts and thrust-related folds on the southern margin of the Bole Basin, northern Tian Shan. These abandonment ages derived from in situ cosmogenic nuclides indicate that climate plays a significant role in controlling the alluvial surface incision. The crustal shortening rates of the eastern Jinghenan, central Jinghenan, and Yongji Faults are 0.21 +/- 0.04, 0.37 +/- 0.07, and 0.91 +/- 0.08 mm/yr, respectively. Based on the fresh fault scarps, three paleo-earthquakes are identified. The oldest paleo-earthquake (16.6 +/- 2.8 kyr) had a Mw of 6.5 +/- 0.3. The penultimate event (3.0 +/- 0.8-4.4 +/- 0.8 kyr) had a Mw of 6.6 +/- 0.3 or 6.8 +/- 0.3, while the most recent one (1.1 +/- 0.3 kyr) had a Mw of 7.0 +/- 0.3 or 6.5 +/- 0.3. Fault geometries and seismic activity indicate these thrusts and right-lateral strike-slip faults on both sides of Keguqin Range converge depth and form a positive half-flower structure. Crustal thickening outpaces denudation, showing that the Bole Basin is in an unsteady state. Keguqin Range is experiencing lateral growth, and as a result, the intermountain basins are expected to gradually diminish.

Dunes react quickly to climatic changes, with the main drivers being the dominating wind regime (e.g. magnitude and direction), precipitation, and temperature. Further, human impact can alter dune movement by fixation of active dunes through greening projects, or reactivation of stationary ones through overgrazing by animals. The north-eastern Tibetan Plateau shows a high variability of climatic parameters like wind, temperature, and precipitation within a high elevation environment, situated between the mid-latitude westerlies and the East Asian Summer monsoon. The presented studies asses active barchan dunes in different climatic settings, from the arid southern margins of the Badain Jaran Desert, to the humid Zoige Basin.Since climate stations on the Tibetan Plateau are rare and their measurements often cover only a short time span, climatic changes were studied from ERA-5 reanalysis data, dating back to the 1950s. These metrics were processed via cloud computing, using Google Earth Engine, and were then compared to dune migration rates, which were deduced from optical satellite imagery. Here, the CORONA KH-4B images from the late 1960s, the Landsat archives, and up-to-date high resolution data (GeoEye and WorldView) were used. The Normalized Difference Vegetation Index (NDVI) was implemented to observe changes in vegetation. As a newly tested metric, dune field density changes were calculated, in order to investigate dynamics of dense dune field setting.Over 500 dunes were mapped and analyzed in total within four focus-areas for comparative purposes. The results highlight a wide range of different behavioral patterns of dunes within the environment of the north-eastern Tibetan Plateau. This showcases how dunes can be influenced by and linked to climatic changes.

Dunes react quickly to climatic changes, with the main drivers being the dominating wind regime (e.g. magnitude and direction), precipitation, and temperature. Furthermore, human impact can alter dune movement by fixation of active dunes through greening projects, or reactivation of fixed dunes through overgrazing or neglect of former human structures. The northeastern Tibetan Plateau shows a high variability of climatic parameters like wind, temperature, and precipitation within a high elevation environment, situated between the mid-latitude westerlies and the East Asian Summer monsoon. This study assesses changes in the movement of active barchans and sand sheets in three different regions of the northeastern Tibetan Plateau and additionally the adjacent Hexi Corridor to evaluate the different impact of climate change and anthropogenic activities in the past 54 years. Over 500 active barchan dunes and 46 sand sheets were studied to assess climatic influence on aeolian deposits. Since weather stations on the Tibetan Plateau are rare and their measurements often cover only a short time span, ERA-5 reanalysis data was utilized. Dune migration rates were deduced from different satellite imagery taken from 1968 onwards. The Normalized Difference Vegetation Index was implemented to observe changes in vegetation. As a further metric, dune field density changes were calculated, to investigate dynamics in dune field settings and human impact from agriculture in the Hexi Corridor. The results show similar migration rates in the Hexi Corridor and the Gonghe Basin with mean values of 8.54 and 7.33 m y(-1), respectively, while in the Source Area of the Yellow River the dunes are migrating slower with a mean of 3.62 m y(-1). The Zoige Basin sand sheets show mostly an expansion in size with a mean growth of 65.39 km(2) y(-1) and a sum extension of 3007.95 km(2) since 1968. The results show the influence of the East Asian Summer Monsoon as a driver for precipitation and subsequent vegetation establishment altering dune movement through fixation. Furthermore, regional dune behavior is influenced by human activities during the past decades, diverting the climatic signal.

Documenting the timing of kinematic reversals along individual strike-slip faults within regional transpressionaltranstensional systems is challenging, especially in areas of subdued topography and limited exposure of basinal successions. Within the northern Tibetan foreland, multiple NW- and W-striking faults (e.g., Nanjieshan, Heishan, Longshoushan) are developed within low-lying ranges, and exhibit Triassic dextral motion followed by a kinematic reversal to Quaternary sinistral slip. However, the timing of the fault inversion is uncertain and ranges from Cretaceous to Quaternary. Resolving this ambiguity is important for documenting the regional crustal evolution of Central Asia and the driving mechanisms for separate tectonic events expressed in the geological record. This study integrates K-Ar illite dating of Nanjieshan fault gouge with field structural analysis, micro-textural observations, and X-ray diffraction (XRD) measurements to constrain the fault inversion timing. Field evidence reveals sinistral strike-slip motion, marked by a left-stepping en-echelon pressure ridge and a 60-m-wide upward-widening fault core. XRD analysis shows increasing detrital illite polytypes with grain size, suggesting preferential 1 M/1Md illite neocrystallization in finer fractions due to fluid-driven fault process. K-Ar dating yields authigenic (122 Ma) and detrital (225 Ma) illite ages. The 122 Ma age robustly constrains Early Cretaceous sinistral reactivation, coeval with Neo-Tethyan subduction and the Lhasa-Qiangtang collision to the south and a dynamically evolving stress field tied to Pacific margin subduction rollback to the east. Regionally, the reactivated Nanjieshan Fault connects eastward to the Heishan-Jinta'Nanshan fault system, forming part of the Altyn Tagh Fault network that truncates NNE-SSW-trending Cretaceous extensional sags or basins (e.g., Jiuquan, Huahai, Chaoshui, Minle). Proposed spatial-kinematic linkages between inverted strike-slip faults and adjacent extensional basins throughout the region suggest the existence of a Cretaceous sinistral transtensional distributed (or mega-) shear fault system. This highlights diffuse transtension as a key mechanism for intraplate deformation.

The eastern Liaoning-southern Jilin tectonic zone (also referred to as the Liao-Ji tectonic zone), a potential zone for rare-metal and REE mineralizations in China, hosts over 10 rare-metal and REE deposits and ore occurrences with varying scales and mineralization characteristics, which establish this zone as an ideal target for research on the metallogenic regularities of rare-metal and REE mineralizations.The study area resides in the northern part of the East Asian continental margin, lying on the overlapping part of the North China and the Western Pacific Plates, is located in the northeastern North China Plate, consisting of the North China Craton and the north margin orogen of the North China Plate. This area serves as a critical large-scale copper-gold and polymetallic mineral resource base in China, also providing favorable geologic conditions for the enrichment and mineralization of rare metals and REEs. So far, many rare-metal and REE deposits and ore occurrences have been discovered in the Liao-Ji tectonic zone, including two large Nb-Be-Zr-REE deposits (i.e., Lijiapuzi and Pianshishan), two medium-sized Rb-Be-Nb-Ta-REE deposits (i.e., Saima and Gangshan), one small Nb-Ta-REE deposit (i.e., Shijia), and over 10 rare metal-REE ore occurrences (e.g., Xiaolizi, and Baiqi), suggesting considerable mineralization potential. Most of the deposits in the Liao-Ji tectonic zone are closely associated with alkaline rocks.Extensive field surveys and geochemical studies of the above deposits reveal that the ore-forming rock masses of the Pianshishan, Gangshan, and Lijiapuzi deposits include alkaline granites and pegmatites and those of the Shijia and Saima deposits are quartz syenites and aegirine nepheline syenites, respectively. The Pianshishan (67±2.2 Ma) and Gangshan (110±1.2 Ma) deposits were formed during the Yanshanian, the Shijia (226.3±2.4 Ma) and Saima (224.4±6.1 Ma) deposits originated from the Late Indosinian magmatism, while the formation of the Lijiapuzi deposit (2501±11 Ma) was associated with the Lvliang Movement. Therefore, the study area underwent three stages of regional rare-metal and REE mineralizations: the Late Yanshanian (Mesozoic), Late Indosinian (Mesozoic), and Proterozoic Lvliangian mineralizations. The petrogeochemical analysis indicates that the ore-forming rock masses of several typical deposits all belong to the metaluminous, alkaline - calc-alkaline, and tholeiitic basalt series, sharing similarities with the elemental geochemical characteristics of intraplate rift rock series and rocks in an extensional environment under plate subduction. The rare-metal and REE mineralizations in the study area were primarily governed by the evolution and crystallization differentiation of alkaline magmas. Given that the alkaline magmatic rocks were all formed by crust-mantle contamination, this study posits that the enrichment and mineralization processes of rare metals and REEs in the Liao-Ji tectonic zone are intimately associated with the highly evolved alkaline magmas. Under the action of water and volatile constituents, magmas underwent intense fractional crystallization, leading to the migration and accumulation of ore-forming elements. With changes in ore-forming conditions such as temperature and pressure, ore-bearing fluids became enriched and mineralized in the late stage of magmatism with the crystallization of primary rock-forming minerals.

Identifying the provenance of aeolian sand is crucial to unraveling the formation and evolution processes of dunes commonly occurring in arid and semi-arid regions. This study presents comprehensive grain size and geochemical data for the mobile dunes (n = 22), vegetated dunes, i.e., dunes stabilized or semi-stabilized by vegetation (n = 26), and fluvial sand samples (n = 10) in the Wulanbuhe (a.k.a. Ulan Buh) Desert (WD) of northwestern China. Major-elemental data and the Al2O3 - CaO*+Na2O+K2O - SiO2 (A-CNK-Si) diagram indicates that dune sands have undergone sedimentary sorting during aeolian transport, although chemical weathering was weak. Spatial variations in grain size and geochemical characteristics within the WD dune sands are not systematically observed, indicating a heterogeneous mixture of materials from diverse sources. Based on the end-members mixing model, this study found differences in the sand sources between the mobile and vegetated dunes in the WD. The bedrock detritus from the surrounding mountains is a dominant source (60 %) of the mobile dune sands in the WD, followed by the paleo-lacustrine deposits from the desert hinterlands (24 %) and the sediments of alluvial fans from the upwind areas (16 %). In contrast, the sands of vegetated dunes were derived from the bedrock detritus (48 %), alluvial fans from the upwind side (32 %), and paleo-lacustrine deposit (20 %), respectively. Our findings confirm that the presence of vegetation on the dune surface influences sediment grain-size characteristics, which in turn affects aeolian erosion and deposition processes, leading to variations in sand source materials.

Dune fields are self-organized systems shaped by nonlinear and dissipative boundary conditions. Decoding their environmental history and linking the spatial and temporal memories are challenging because the signals of environmental forcings that propagate across horizontal landscapes and get archived into vertical strata are susceptible to being shredded, reorganized, and even erased. Here we provide a real-world prototype of the coupling between spatial and temporal signals in the Wulanbuhe and Kubuqi deserts of northern China, using geospatial analysis, chrono-geographic nearest neighbor-based paleoenvironmental reconstruction, and numerical simulation. We find that the two supposedly independent deserts share similarly abrupt transitions in sand accumulation thickness near a reconstructed paleolake shoreline, suggesting their coevolution with the nearby mega paleolake. This transition in dune-field patterns manifests the history of boundary condition changes triggered by the hydrological system alterations. Our study demonstrates that a detailed investigation of spatial patterns in dune landscapes can help reconstruct the history of boundary condition changes, applicable not only on Earth but also on extraterrestrial planets.

Most current point cloud super-resolution reconstruction requires huge calculations and has low accuracy when facing large outdoor scenes; a Dense Feature Pyramid Network (DenseFPNet) is proposed for the feature-level fusion of images with low-resolution point clouds to generate higher-resolution point clouds, which can be utilized to solve the problem of the super-resolution reconstruction of 3D point clouds by turning it into a 2D depth map complementation problem, which can reduce the time and complexity of obtaining high-resolution point clouds only by LiDAR. The network first utilizes an image-guided feature extraction network based on RGBD-DenseNet as an encoder to extract multi-scale features, followed by an upsampling block as a decoder to gradually recover the size and details of the feature map. Additionally, the network connects the corresponding layers of the encoder and decoder through pyramid connections. Finally, experiments are conducted on the KITTI deep complementation dataset, and the network performs well in various metrics compared to other networks. It improves the RMSE by 17.71%, 16.60%, 7.11%, and 4.68% compared to the CSPD, Spade-RGBsD, Sparse-to-Dense, and GAENET.

Arid and semiarid regions are environmentally vulnerable to global warming. Thus, studying their environmental history during warm periods (e.g., the Last Interglacial, LIG) is crucial for understanding their future changes too. The West Gobi Desert is a transitional zone influenced by the westerlies and the East Asian monsoon system. Therefore, the variation in atmospheric circulation profoundly affects its water vapor transport and landscape evolution. Due to the scarcity of continuous records, the moisture transport process remains ambiguous, which limits further research on paleolake evolution and aeolian activity. Here, we combine paleoclimate simulations from the Coupled Model Intercomparison Project (CMIP6)-Paleoclimate Modeling Intercomparison Project 4 (PMIP4) and geological records to clarify the water vapor transport pathways and aeolian activity in the West Gobi Desert during the LIG, compared to the reference period (the piControl). Our results show that increased rainfall and meltwater were possible supplies for surface water during the LIG and were associated with enhanced East Asian summer monsoon and higher surface air temperatures. Concomitantly, weakening aeolian activity and dormant dune fields occurred in the West Gobi Desert, resulting from higher surface moisture content and weaker surface wind regimes associated with the weakening westerlies and East Asian winter monsoon. Notably, the limited weakening of aeolian activity that occurred in the LIG winter and spring was caused by weaker surface wind and deteriorating surface moisture conditions, while the significant dormancy of dune fields in the LIG summer and autumn was initiated by the combined effects of ameliorative surface moisture conditions and lower surface wind speed.

Objective. PET (Positron Emission Tomography) inherently involves radiotracer injections and long scanning time, which raises concerns about the risk of radiation exposure and patient comfort. Reductions in radiotracer dosage and acquisition time can lower the potential risk and improve patient comfort, respectively, but both will also reduce photon counts and hence degrade the image quality. Therefore, it is of interest to improve the quality of low-dose PET images. Approach. A supervised multi-modality deep learning model, named M 3 S-Net, was proposed to generate standard-dose PET images (60 s per bed position) from low-dose ones (10 s per bed position) and the corresponding CT images. Specifically, we designed a multi-branch convolutional neural network with multi-self-attention mechanisms, which first extracted features from PET and CT images in two separate branches and then fused the features to generate the final generated PET images. Moreover, a novel multi-modality structure-promoting term was proposed in the loss function to learn the anatomical information contained in CT images. Main results. We conducted extensive numerical experiments on real clinical data collected from local hospitals. Compared with state-of-the-art methods, the proposed M 3 S-Net not only achieved higher objective metrics and better generated tumors, but also performed better in preserving edges and suppressing noise and artifacts. Significance. The experimental results of quantitative metrics and qualitative displays demonstrate that the proposed M 3 S-Net can generate high-quality PET images from low-dose ones, which are competable to standard-dose PET images. This is valuable in reducing PET acquisition time and has potential applications in dynamic PET imaging.

On 1 June 2022, a magnitude 6.1 earthquake struck the southern segment of the Longmenshan fault zone on the eastern edge of the Tibetan Plateau, once again causing casualties and economic losses. Understanding the deep-seated dynamic mechanisms that lead to seismic events in the Lushan earthquake area and assessing the potential hazards in seismic gap areas are of significant importance. In this study, we utilized 118 magnetotelluric datasets collected from the Lushan earthquake area and employed three-dimensional electromagnetic inversion with topographic considerations to characterize the deep-seated three-dimensional resistivity structure of the Lushan earthquake area. The results reveal that the Shuangshi–Dachuan fault in the Lushan earthquake area can be divided into two relatively low-resistivity zones: a western zone dipping southeastward and an eastern zone with a steeper slightly northwestern dip. These two zones intersect at a depth of approximately 20 km, forming an extensional pattern resembling a “Y” shape. The epicenters of both the 2013 and 2022 Lushan earthquakes are primarily located in the upper constricted portion of the pocket-like low-resistivity body at depth. The distribution of seismic aftershocks is confined within the region enclosed by the high-resistivity body, following the pattern of the Y-shaped low-resistivity zone.

This paper proposes a point-by-point weighted fusion algorithm based on an improved random sample consensus (RANSAC) and inverse distance weighting to address the issue of low-resolution point cloud data obtained from light detection and ranging (LiDAR) sensors and single technologies. By fusing low-resolution point clouds with higher-resolution point clouds at the data level, the algorithm generates high-resolution point clouds, achieving the super-resolution reconstruction of lidar point clouds. This method effectively reduces noise in the higher-resolution point clouds while preserving the structure of the low-resolution point clouds, ensuring that the semantic information of the generated high-resolution point clouds remains consistent with that of the low-resolution point clouds. Specifically, the algorithm constructs a K-d tree using the low-resolution point cloud to perform a nearest neighbor search, establishing the correspondence between the low-resolution and higher-resolution point clouds. Next, the improved RANSAC algorithm is employed for point cloud alignment, and inverse distance weighting is used for point-by-point weighted fusion, ultimately yielding the high-resolution point cloud. The experimental results demonstrate that the proposed point cloud super-resolution reconstruction method outperforms other methods across various metrics. Notably, it reduces the Chamfer Distance (CD) metric by 0.49 and 0.29 and improves the Precision metric by 7.75% and 4.47%, respectively, compared to two other methods.

Active faults serve as potential sources of destructive earthquakes. Studies and investigations of active faults are necessary for earthquake disaster prevention. This study presents a nation-scale database of active faults in China and its adjacent regions, in tandem with an associated web-based query system. This database is an updated version of the active faults data included in the Seismotectonic Map of China and its Adjacent Regions (1:4 000 000), which is one of the four essential maps of the mandatory Chinese standard GB 18306-2015 Seismic Ground Motion Parameter Zonation Maps of China. The data update and integration stem from regional-scale studies and surveys conducted over the past 2 decades (at reference scales from 1:250 000 to 1:50 000). The information amassed from these regional-scale studies and surveys encompasses geophysical probing, drill logging, measurement of offset landforms, sample dating, as well as geometric and kinematic parameters of exposed and blind faults, paleo-earthquake sequences, and recurrence intervals. These data have been acquired and analyzed utilizing a uniform technical standard framework and reviewed by expert panels in both field and laboratory settings. Our system hosts this nation-scale database accessible through a Web Geographic Information System (GIS) application, enabling browsing, querying, and downloading functionalities via a web browser. The system we built also publishes the Open Geospatial Consortium (OGC) Web Feature Service and the OGC Web Map Service of active faults data. Users can incorporate map layers and obtain fault data in OGC-compliant GIS software for further analysis through these services. The Chinese government, research institutions, and companies have widely used the active faults data from the previous versions of the database. The database is available at https://doi.org/10.12031/activefault.china.400.2023.db (Xu, 2023) and via the web system (https://data.activetectonics.cn/arcportal/apps/webappviewer/index.html?id=684737e8849c4170bbca14447608c451, CEFIS, 2023; http://data.activetectonics.cn/arcserver/services/Hosted/CAFD400_2022_WFS/MapServer/WFSServer, CAFD WFS, 2024).