Search Results (519)

To provide reliable impact protection for a flying car power battery pack under stringent lightweight requirements, especially under takeoff, landing, and drop impact scenarios, a biomimetic metamaterial sandwich enclosure inspired by the hierarchical protective architecture of a tortoise carapace is proposed. The enclosure is composed of an outer shell, an internal sandwich core, and an inner plate, through which load diffusion and deformation buffering can be achieved by multilayer structural coordination. Firstly, three core configurations, including conventional honeycomb, a chiral structure with negative Poisson’s ratio (NPR) characteristics, and an NPR concave structure, are comparatively investigated through high-speed impact finite element simulations. The NPR concave structure is regarded as the preferred core configuration due to its more balanced energy absorption behavior and superior deformation stability. Afterwards, the NPR concave structure is embedded into the full battery pack enclosure, and the protective performances of the proposed battery pack are evaluated under representative flying car operating conditions. Compared with those of the conventional honeycomb, the maximum displacement of the proposed battery pack decreases by 49.31% under the takeoff-and-landing overload condition, and the maximum intrusion decreases by 25.94% under the drop impact condition. The results indicate that the tortoise-carapace-inspired metamaterial sandwich structure effectively enhances the deformation resistance and anti-intrusion capability of a flying car battery pack, thereby providing a feasible structural design approach for battery protection in flying car applications. Full article

As a complex heritage site embodying maritime defense civilization, the Ming Dynasty Coastal Defense Garrisons face a profound contradiction between protection and development. Current research has failed to effectively explain the spatial mechanism of the transformation of coastal defense garrisons from military fortresses to modern towns. This study selects three coastal defense garrisons in southern Zhejiang—Jinxiang Garrison, Puzhuang Fort, and Hai’an Fort—and, based on long-term spatial data from 1969 to 2025, uses GIS, spatial syntax, and fractal index methods to construct a morphological analysis framework from four dimensions: architecture, land parcels, streets and alleys, and boundaries, revealing their evolutionary patterns and functional transformation mechanisms. The results show that (1) morphological evolution follows an asynchronous and coordinated rhythm of “buildings filling in first, road network updating lagging behind, and boundaries continuously constraining.” (2) Differences in urbanization pressure, industrial implantation intensity, and cultural heritage management drive the three garrisons to differentiate into three transformation paths: gradual preservation, radical reconstruction, and balanced regularization. The intensity of street and alley renovation is the core indicator for judging whether the historical fabric is preserved. (3) The boundaries of the garrison exhibit a “macroscopically regular but microscopically fragmented” characteristic, with a simple outer boundary and a complex inner boundary. Even after the city walls disintegrated, the moat still served as a morphological inertial line, maintaining the stability of the macroscopic outline. This research can provide quantitative evidence and empirical reference for the differentiated protection of coastal defensive heritage. Full article

Against the backdrop of optimizing national energy mix and advancing industrial low-carbon transformation to achieve sustainable socioeconomic development, this study adopts prefecture-level panel data covering 2005–2020 to reveal the spatiotemporal evolution law of carbon emissions generated by urban energy consumption. We systematically characterize emission disparities from three dimensions: total carbon output, per capita carbon emissions, and carbon emission intensity, and further adopt regression analysis to quantitatively identify core socioeconomic and industrial drivers behind energy-related carbon flows. The results indicate that China’s total urban energy carbon emissions kept rising over the research window with decelerating growth momentum. Driven by cross-regional industrial transfer and uneven energy resource endowments, high-emission zones gradually spread from eastern coastal agglomerations to northern and western inland territories, forming a stable spatial layout of high emissions in the east and north, and low emissions in the west and south. Per capita carbon emissions present striking regional differentiation: northwest resource-abundant provinces become concentrated high-value clusters, while populous southeast regions maintain relatively low levels, with inter-regional per capita emission gaps continuously widening. Nationwide carbon emission intensity maintained a persistent downward trend; high-intensity zones shrank markedly while low-carbon areas expanded continuously, and inter-regional efficiency gradients gradually converged, reflecting tangible achievements in nationwide energy conservation and low-carbon industrial transition. Overall, the gravity center of energy carbon emissions shifted northwestward, with Inner Mongolia, Xinjiang, and Ningxia evolving into major high-emission hotspots relying on fossil energy exploitation and heavy industrial layout. Statistical regression associations suggest that urban construction land expansion, economic expansion, foreign capital agglomeration, and industrial energy carbon outputs are positively correlated with urban carbon emissions; by contrast, commercial housing scale and domestic enterprise development present significant negative correlational links with emission levels. The differentiated spatiotemporal carbon landscape arises from the joint interplay of regional resource endowment, coal-dominated energy structure, industrial layout restructuring, and tiered low-carbon policy implementation, demonstrating China’s overall shift from high-carbon extensive industrial growth toward energy-efficient, low-carbon intensive sustainable development. This research delivers empirical evidence for formulating zoned carbon abatement schemes, optimizing regional energy allocation and industrial layouts, and advancing long-term low-carbon sustainable development to fulfill China’s carbon peaking and carbon neutrality targets. Full article

Automated detection of lunar impact craters from digital elevation model (DEM) data is important for lunar geological analysis, landing-site selection, and crater catalog updating. However, this task remains challenging because lunar craters exhibit large scale variations, weak or degraded rims, ambiguous boundaries, and complex topographic backgrounds. In addition, large-scale lunar remote sensing applications require detection models to achieve a reasonable balance among accuracy, model complexity, and inference efficiency. To address these challenges, this study proposes FPW-YOLO11n, a frequency-perception crater detection method developed based on YOLO11n. First, a Frequency-Directional Attention Module (FDA-Module) is introduced into the shallow stage of the backbone. This module combines frequency-aware channel attention and direction-aware spatial attention to enhance the representation of crater rim structures, elevation variations, and directional topographic cues in DEM data. Second, a C2PSA-LRSA module is designed by embedding Local Region Self-Attention into the C2PSA framework, thereby improving local contextual feature interaction while reducing the excessive cost associated with global self-attention. Third, Inner-WIoU is adopted to replace the original CIoU loss in YOLO11n. By combining the auxiliary-box mechanism of Inner-IoU with the sample-quality-aware weighting strategy of WIoU, Inner-WIoU provides a more flexible bounding-box regression objective for craters with weak rims, scale variations, and uncertain boundaries. A DEM-based lunar crater dataset was constructed from the Moon LRO LOLA–SELENE Kaguya TC DEM Merge 60N60S 59m product and the Robbins lunar crater catalog, covering the non-polar region from 60° S to 60° N and containing 4760 image tiles. Under the random data-splitting strategy, FPW-YOLO11n achieves 78.3% Precision, 66.2% Recall, 75.1% mAP@0.5, and 50.2% mAP@0.5:0.95, outperforming the YOLO11n baseline by 1.2, 2.0, 1.6, and 4.0 percentage points, respectively. Additional experiments based on geographically disjoint data splitting further show that the proposed method consistently performs better than YOLO11n on DEM data, indicating that the proposed structural improvements remain effective under a more rigorous spatially independent evaluation setting. Although the computational cost increases from 6.3 to 24.0 GFLOPs, FPW-YOLO11n maintains a compact parameter size of 2.59 M and a high inference speed, demonstrating an improved accuracy–efficiency trade-off for lunar crater detection from DEM data. Full article

Wind power development is accelerating globally, leading to an imminent large-scale retirement of wind turbines and increasing the need for recycling infrastructure. This study proposes an integrated framework for recycling center site selection by combining Geographic Information System (GIS), AHP–CRITIC weighting, and Super-Efficiency Data Envelopment Analysis (DEA). A hierarchical GIS indicator system is constructed by incorporating environmental, locational, and social compatibility factors, including elevation, slope, land use, transportation accessibility, proximity to wind farms, and population-related constraints. GIS performs Euclidean distance, kernel density, and weighted overlay analyses to identify suitable areas, while indicator weights are determined through a hybrid subjective–objective approach. A Super-Efficiency DEA model is then applied, using labor and land costs as inputs and annual decommissioning quantities as output, to evaluate and rank candidate sites, with higher-ranked sites regarded as reliable locations. A case study in Xilingol, Inner Mongolia, verifies the method’s effectiveness. The proposed framework supports scientific planning for wind turbine recycling and promotes sustainable wind energy development. Full article

Against the backdrop of the growing alignment between green agricultural transformation and rural land system reform, how stable land tenure promotes farmers’ adoption of green production technologies has become an important issue in achieving high-quality agricultural development. Using 2024 survey data from 1117 farm households in Inner Mongolia under China’s second-round land contract extension policy, this study applies Poisson regression and mediation models to examine how land tenure stability affects farmers’ adoption of green production technologies. The results show that legal, factual, and perceived tenure stability, measured by second-round contract extension signing, no land disputes since the second round, and expectations of no future land adjustment, all significantly promote adoption. Tenure stability promotes adoption through higher income, better credit access, stronger benefit expectations, and greater risk-coping capacity, reflecting both economic and psychological effects. Its positive effect is stronger among small-scale farmers and those with lower-quality cultivated land. Policy efforts should not only prudently advance the second-round land contract extension, but also strengthen tenure security in practice and coordinate support for green production, rural finance, and risk protection. From a multidimensional land tenure stability perspective, this study provides new empirical evidence on how rural land reform translates into green behavioral responses. Full article

To address escalating natural and market risks in agriculture, integrated crop–livestock systems (ICLS) are increasingly recognized as a production mode combining resilience and sustainability. Using survey data from 372 farm households in Inner Mongolia, China, this study first constructs a directional income volatility indicator and applies the Kruskal–Wallis test together with robust tests for equality of variances to compare the short-term risk-buffering performance of specialized cropping, specialized livestock production, and ICLS. The analysis then focuses on 190 ICLS households and employs Hansen’s threshold model to identify nonlinear constraints on achieving higher income and examine potential equipment misallocation. The results show a stronger short-term risk-buffering advantage of ICLS over the two specialized modes. Livestock inventory scale exhibits a threshold effect: at a lower livestock inventory scale, livestock expansion is significantly associated with lower income, whereas beyond this threshold the marginal effect becomes significantly positive. Crop–livestock structural matching, measured by the livestock–land ratio, constrains the income effect of livestock expansion: once the ratio reaches a certain level, livestock expansion no longer shows a significant negative association with income. In addition, mismatches between machinery investment and production orientation weaken the income performance. These results imply that policy should promote ICLS in a context-specific and moderate manner, guide farmers toward better crop–livestock alignment, and expand agricultural service provision to reduce risks associated with misaligned mechanization. Full article

Desertified soils severely limit vegetation restoration and sustainable land use in arid regions. This study aims to evaluate the individual and combined effects of coal-based charcoal produced by coal pyrolysis and organic fertilizer on soil properties and the growth performance of Amorpha fruticosa L. A pot experiment was conducted using degraded sandy soil collected from Inner Mongolia, with amendment rates of 2.5%, 5%, and 10% (w/w) for each material, and a combined treatment (2.5% coal-based charcoal + 2.5% organic fertilizer). The results showed that all treatments reduced soil bulk density (BD) and increased electrical conductivity and nutrient availability. Application of coal-based charcoal increased soil pH, whereas organic fertilizer decreased it, and their combined application resulted in a more balanced soil pH. The combined treatment (FT) achieved the highest germination rate (83.33%), significantly improved root morphological traits, enhanced chlorophyll content and the photosynthetic rate, and increased peroxidase, superoxide dismutase, and catalase activities, while reducing malondialdehyde content. These findings suggest that combining coal-based charcoal with organic fertilizer provides complementary benefits, enhancing soil physicochemical properties and plant physiological performance, thereby promoting the growth of A. fruticosa L. and providing an effective strategy for restoring desertified soils. Full article

This study investigates the spatiotemporal dynamics of peri-urban expansion and land use transformation in Izmir, Türkiye, over 36 years (1986–2022) using an integrated GIS-based Multi-Criteria Decision Analysis (MCDA) framework. Multi-source datasets, including Landsat imagery, CORINE land cover (CLC) data, demographic statistics, and spatial variables (slope, transportation proximity, and distance to the city center), were combined to delineate urban, peri-urban, and rural zones. Results reveal a substantial percentage increase in urban areas from 2.8% in 1986 to 10.48% in 2022, corresponding to an expansion of approximately 7.6% (≈908.56 km²). In contrast, agricultural land declined by 5.8%, while forest areas experienced a more severe reduction of 19.1%, indicating significant environmental degradation. Population dynamics further support this transformation, with peri-urban districts exhibiting growth rates exceeding the metropolitan core average of 1.8% (1986–2010), followed by a relative slowdown to 0.5% after 2010, accompanied by outward migration-driven expansion. Spatial analysis demonstrates that peri-urban growth is strongly influenced by accessibility and topography, with development concentrated within 30–50 km of the city center and along major transportation corridors (500–1000 m buffers). Land Surface Temperature (LST) analysis indicates increasing urban heat island intensity, with surface temperatures ranging from 12 °C to 46 °C, particularly in densely built inner peri-urban zones. The MCDA-based classification identifies distinct inner and outer peri-urban belts, characterized by contrasting density, land use patterns, and environmental pressures. Overall, the findings highlight that Izmir’s peri-urbanization is a heterogeneous and rapidly evolving process driven by demographic, spatial, and policy-related factors. The study provides a replicable methodological framework and emphasizes the urgent need for integrated, sustainability-oriented planning strategies to mitigate ecological loss and uncontrolled urban sprawl. Full article

To clarify the effects of biochar application on leaf photosynthesis, dry matter accumulation, and productivity in a maize–soybean intercropping system, a two-year field experiment was conducted in the Yellow River irrigation area of Inner Mongolia from 2024 to 2025. A split-plot design was adopted with two biochar application rates (0 and 5 t ha⁻¹) and three cropping patterns, including maize monoculture, soybean monoculture, and maize–soybean 2:4 intercropping. Leaf SPAD values, photosynthetic characteristics (Pn, Tr, Gs, and Ci), yield components, and land equivalent ratio (LER) were determined. Compared with maize monoculture, intercropping significantly increased maize SPAD values at the V12 and VT stages by 12.80% and 13.39% in 2024 and by 15.41% and 20.58% in 2025, respectively, and enhanced maize Pn, Tr, and Gs at the V12 and R1 stages. Soybean showed greater sensitivity to intercropping, with reduced SPAD values, Pn, Tr, and Gs during the branching, flowering, and pod-setting stages, whereas biochar application partially alleviated these inhibitory effects. Intercropping increased maize kernel number per ear and thousand-kernel weight but reduced soybean effective plant density, grain number per plant, and grain yield. Biochar application improved the grain yield of both intercropped maize and soybean. Under biochar application, the LER values reached 1.04 in 2024 and 1.21 in 2025, indicating a clear advantage in land-use efficiency. Overall, biochar application and maize–soybean intercropping were associated with improved photosynthetic performance, higher land-use efficiency, and increased system productivity. Full article

Siziwang Banner in Inner Mongolia is a typical arid and semi-arid grassland region where ecological environmental quality is highly sensitive to climate variability and land use and land cover change (LULCC). Clarifying the long-term coupling relationship between LULCC and ecological environmental quality is essential for regional ecological protection and sustainable land management. Based on the Google Earth Engine (GEE) platform, this study integrated multi-temporal Landsat imagery and CLCD-based land use datasets, including an updated 2024 land use layer, to construct a Remote Sensing Ecological Index (RSEI) using standardized and direction-corrected principal component analysis. land use transition matrix analysis, spatial autocorrelation analysis, ecological contribution rate calculation, and GeoDetector were further applied to reveal the spatiotemporal evolution patterns, ecological effects, and driving mechanisms of LULCC in Siziwang Banner from 2000 to 2024. The results showed that: (1) grassland was consistently the dominant land use type, accounting for more than 90% of the total area. The overall land use pattern was characterized by stable grassland dominance, decreasing farmland and unused land, and slight increases in grassland and construction land; forestland showed a high relative growth rate but remained very small in absolute area. (2) The regional ecological environmental quality remained at a lower-to-medium level, with mean RSEI values ranging from 0.27 to 0.47. RSEI showed a phased pattern of initial improvement, subsequent decline, and partial recovery; the marked decline around 2015 was associated with the combined effects of drought stress and land use degradation rather than a single driving factor. RSEI exhibited significant positive spatial autocorrelation, with Moran’s I values ranging from 0.898 to 0.993. High-value clusters were mainly distributed in the southern region, whereas low-value clusters were concentrated in the central and northern regions. (3) Different land use transitions produced differentiated ecological effects. The conversion of unused land to grassland contributed positively to ecological restoration, while grassland degradation and construction land expansion exerted negative effects. The positive RSEI response of some grassland-to-farmland transitions should be interpreted cautiously in relation to local irrigation and intensive farmland management. (4) GeoDetector results indicated that land use type and DEM were the dominant factors controlling the spatial differentiation of RSEI, with average q values of 0.7188 and 0.6178, respectively. The interaction between DEM and land use type showed the strongest explanatory power, indicating that ecological quality was jointly shaped by land use structure and natural background conditions. This study provides a scientific basis for grassland protection, unused-land restoration, farmland management, and spatially differentiated ecological restoration in Siziwang Banner and similar ecologically fragile arid and semi-arid grassland regions. Full article

The three-dimensional (3D) built environment encodes critical information about urban form intensity, environmental exposure, and resource consumption. However, previous studies have often overlooked the integration of long-term analyses of both horizontal expansion and vertical growth. This study aims to identify the spatial differentiation, morphology types, and vertical growth trajectories of major Chinese megacities over the past three decades. Using high-resolution GABLE building data and time-series GAIA impervious surface data, we examine the evolution of urban 3D morphology across six major Chinese megacities from 1991 to 2023 through a retrospective analysis of building construction years combined with spatial gradient analysis. The results reveal that although the megacities exhibit distinct differences in vertical structure, shape complexity, and spatial compactness, they share a consistent center-to-periphery gradient across most 3D indicators. The most active volumetric growth was concentrated in a zone 8–14 km from city centers, which accounted for 23.6% of total new development, whereas the inner core within 6 km contributed less than 2.68%. In terms of temporal dynamics, Beijing, Shanghai and Guangzhou follow an inverted-V-shaped 3D expansion trajectory driven by mid-rise construction; Tianjin and Hangzhou show accelerated growth with a higher proportion of high-rise clusters; while Shenzhen demonstrates an early peak and a decelerated growth rate, accompanied by a pronounced polycentric pattern. While recent global-scale studies have suggested a shift from outward urban sprawl to vertical development, our findings indicate that horizontal expansion still dominates in the selected Chinese megacities, with outward sprawl exceeding vertical densification during the study period. The integrated approach provides a robust framework for mapping 3D urbanization and offers practical insights for policymakers seeking to manage horizontal expansion, guide vertical intensification, and optimize land-use efficiency in rapidly urbanizing megacities. Full article

Shipboard helicopter landing in the near-deck region requires stable attitude regulation and high-precision deck-relative motion control under substantial model uncertainty and environmental disturbances, conditions under which conventional model-based controllers may lose performance or become overly conservative. This paper proposes a task-oriented, learning-enhanced control algorithm for ship-relative near-deck station keeping and landing by integrating a model-based baseline controller with residual reinforcement learning in a deck-relative closed-loop framework. The algorithmic contribution is the deck-relative baseline–residual control architecture: a split-channel incremental nonlinear dynamic inversion (INDI) outer loop and a reduced-order dynamic inversion (DI) inner loop provide the nominal baseline pathway, while a bounded residual Proximal Policy Optimization (PPO) policy supplies compensation in the same physical outer-loop command channels to suppress unmodeled nonlinearities and time-varying disturbances. Simulation results show that Residual PPO improves hover robustness and landing performance relative to the baseline controller and Pure PPO. With approximately 20–30% residual authority, it achieved 90.0% Desired landing rates in both tested descent-and-landing scenes. Full article

The Northwest soybean production region (covering Shanxi, Shaanxi, Gansu, Ningxia, Xinjiang, central and western Inner Mongolia and northern parts of Hebei) possesses vast cultivated land resources and advantageous light–temperature conditions, endowing soybean with substantial yield potential. In this study, two natural soybean populations originating from this region were used to systematically investigate the phenotypic variation in two important agronomic traits, plant height (PH) and main stem node number (NN). The results showed abundant genetic variation for both traits. Through genome-wide association analysis (GWAS) and employing a joint detection across multi-environments (control false positives), 5 SNPs significantly associated with PH and 18 SNPs significantly associated with NN were identified, among which four SNPs were detected associated with both traits. Candidate genes were further screened within the ±100 kb intervals flanking lead SNPs at association peaks. By integrating gene expression levels of different soybean tissues and their correlations with the phenotypes, two candidate genes associated with both PH and NN were determined. These findings provide a theoretical basis for the identification and utilization of soybean germplasm resources in Northwest China, and lay a solid foundation for breeding high-yield and high-quality soybean varieties through molecular breeding. Full article

Grassland ecological governance is a systematic project integrating natural and social attributes, involving pastoral social structure adjustment and herders’ livelihood transformation. Pastoral households are the basic production units and direct ecological responsibility bearers in Inner Mongolia. Based on 2001–2023 statistical data and 2014–2023 field surveys, this study adopts an integrated mixed-methods approach: quantitative trend analysis is used to identify long-term changes in household number and size, while qualitative thematic coding of interviews and participatory observation is applied to interpret behavioral logic and governance mechanisms, so as to achieve mutual verification and complementarity between the two data types. We find that pastoral household numbers grew rapidly after 2010 and remained high. By 2023, the number reached 641,500, with average household size dropping to 2.89 people. Driven by ecological subsidy policies, grassland tenure confirmation, and livestock market returns, household scale shrank and grassland was fragmented. The three spontaneously formed ecological governance functions—population regulation, grass-livestock balance, and human-land adjustment—have weakened and shifted from “spontaneous governance” to “passive response.” Herder differentiation in this paper refers to the stratification of pastoral households into distinct groups in terms of livestock scale, grassland area, livelihood structure, and governance capacity, forming heterogeneous behavioral patterns and policy responses. Future governance should abandon the one-sided label of herders as “ecological destroyers,” improve differentiated subsidy policies, and support joint household governance to revitalize endogenous governance capacity. Full article