Search Results (820)

Dissolved organic matter (DOM) in the water column and sediments in coal mining subsidence areas considerably affects the carbon cycle and ecological environment. This study analyzed the spectral characteristics, material composition, and molecular transformation of DOM in the water column and sediments of a coal mining subsidence area in Huaibei, China, using ultraviolet–visible absorption spectroscopy, three-dimensional fluorescence spectroscopy combined with the parallel factor analysis (PARAFAC) model, and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The DOM concentration (11.99 ± 4.73 mg/L) and the degree of DOM humification in the sediment were higher than those (9.54 ± 0.68 mg/L) in the water column. The PARAFAC model revealed three chemical components: fulvic acid–like, protein-like, and humus-like substances. DOM in the water column is primarily derived from endogenous inputs, characterized by low humification and high biological activity. In contrast, DOM in the sediments primarily originates from external inputs. FT-ICR MS analysis revealed that lignin-like (50.80–67.02%), protein-like (13.18–18.38%), and lipid-like (5.74–10.39%) components are the main DOM constituents in the water column and sediments, with lignin content in the water column (66.16%) being higher than that in the sediments (55.09%). Paired mass difference network analysis identified redox reactions as the predominant reactions in the water column and sediments, converting aldehydes or carbonyl compounds into acids or alcohols. This study elucidates the composition and transformation characteristics of DOM in the water column and sediments in coal mining subsidence areas, providing a scientific foundation for the protection and management of aquatic ecosystems. Full article

Building footprint extraction in high-density urban areas remains difficult because spectral confusion and shadows obscure building–background differences, while dense adjacency and complex boundaries hinder boundary recovery and adjacent-building separation. To address these issues, this study combines Digital Orthophoto Maps (DOM) and normalized Digital Surface Models (nDSM) and develops ACM-PSPNet for high-density built-up areas of Hong Kong. ACM-PSPNet extends the PSPNet baseline by integrating atrous spatial pyramid pooling and convolutional block attention for high-level contextual enhancement and feature recalibration, together with an MS-Fuse decoder for progressive multilevel spatial-detail recovery. The main experiments were independently repeated three times and evaluated on a spatially independent test set. In the input-source comparison, DOM+nDSM yielded a mean IoU of 84.94%, compared with 68.23% for DOM and 83.23% for nDSM alone. Using DOM+nDSM as the common input, the model comparison showed that ACM-PSPNet provided the highest performance among the eight evaluated models, with mean IoU, F1 Score, and Boundary F1 values of 87.81%, 93.13%, and 79.78%, respectively. In selected typical scenes, the under-segmentation proportion decreased from 35.7% for PSPNet to 5.0% for ACM-PSPNet. The results support ACM-PSPNet as an accuracy-oriented framework for dense urban building mapping, particularly where reliable boundary recovery and adjacent-building separation are required, although broader cross-city and cross-sensor validation remains necessary. Full article

Undercutting significantly affects the mechanical stability of earthen archaeological sites and represents a critical parameter for heritage conservation decision-making. To quantify undercutting volume, this study developed a methodology coupling close-range photogrammetry with semantic segmentation. We selected seven earthen sites spanning diverse climatic and historical contexts, acquired 3D models, and generated RGB-DSM fused images. A dataset of 576 samples was established with manual annotations of undercutting and co-occurring deterioration (holes, fissures, and gullies). For deterioration identification, we employed an enhanced U-Net architecture featuring reduced down-sampling, a dilated convolution context module in the bottleneck, an FPN-style decoder, and an optimized loss function. The model achieved per-class IoU values of 0.485–0.510 for co-occurring deterioration and 0.668 IoU (0.801 F₁-score) for undercutting. Volume was computed by fitting a reference surface above the undercutting zone and integrating pixel-wise elevation differences. Analysis showed that DOM/DSM should be acquired as perpendicular to the wall as possible, because angular deviations introduce geometric underestimation of the area and reduce recognition performance. The observed volume CV of 8–25% far exceeds the theoretical 4.2% from geometry alone, confirming recognition variability as the dominant uncertainty source. By simplifying 3D point cloud recognition to a 2D image task, this approach avoids prohibitive annotation and computational costs, offering a practical solution for linearly distributed earthen sites and providing essential data for structural safety assessment and deterioration mechanism studies. Full article

Continental shale reservoirs exhibit pronounced multi-scale heterogeneity, with reservoir quality governed by the interplay of lamina assemblages, bedding continuity, and lithological spatial variability. Conventional digital outcrop modeling (DOM) primarily targets geometric reconstruction and three-dimensional (3D) visualization of sedimentary bodies, which is insufficient for the fine-scale structural characterization and quantitative modeling required for shale reservoirs. Here we present a Digital Shale Outcrop Modeling method (DSOM) tailored to continental shale reservoirs, exemplified by the Gulong Shale in the Qingshankou Formation (Upper Cretaceous) of the Songliao Basin, northeastern China. DSOM integrates six sequential modules: digital outcrop reconstruction, digital section interpretation, virtual well construction, virtual well correlation, 3D structural modeling, and parameter extraction. A high-precision digital outcrop model covering 0.369 km² was constructed from 1885 calibrated UAV images (DJI Mavic 3 Enterprise) using Structure-from-Motion (SfM) photogrammetry, yielding derived products including a digital outcrop model (DOM), digital surface model (DSM), digital elevation model (DEM), orthomosaic, and dense point cloud. Seven virtual wells were extracted along the outcrop strike, and a unified lithological classification comprising seven lithotypes was established. A regionally persistent rusty-yellow ferruginous siltstone layer served as a marker bed for virtual well correlation. Results reveal a distinct vertical lithological transition: the section above the marker bed is dominated by muddy deposits, with black mudstone and dark-gray silty mudstone collectively accounting for 52.84% of the total area, whereas the section below the marker bed exhibits a marked increase in silt-grade material, with gray siltstone reaching 32.78%. This vertical evolution reflects a depositional shift from relatively high-energy to low-energy conditions. Using the virtual wells as conditioning data, 3D lithological probability models for all seven lithotypes were constructed via Sequential Indicator Simulation (SIS), achieving quantitative representation of lithological spatial distribution and lateral variability under bedding constraints. Our results demonstrate that DSOM effectively converts outcrop digital information into reservoir structural data, providing reliable constraints for multi-scale structural characterization, 3D geological modeling, and heterogeneity evaluation of the Gulong Shale. More broadly, DSOM establishes a methodological framework for digital characterization of fine-grained sedimentary reservoirs, bridging the gap between outcrop-scale observations and subsurface reservoir modeling. Full article

Salt-affected soil constrains maize establishment, and rhizosphere and non-rhizosphere responses to soil biochar remain difficult to establish. We evaluated soil physical and nitrogen properties, qPCR marker genes, 16S and ITS communities, and molecular profiles of dissolved organic matter (DOM) in a 90-day randomized complete block pot experiment (four biochar rates; five blocks; 20 pots). Control maize did not survive; control pots therefore yielded only non-rhizosphere soil, whereas rhizosphere and non-rhizosphere samples from biochar pots were paired. Block-adjusted comparisons showed higher water content and porosity and lower bulk density in all biochar non-rhizosphere groups than in the control (Holm-adjusted p < 0.05). Biochar-associated shifts in mineral-N partitioning and selected DNA-level marker-gene abundances accompanied design-aware community differences for NR treatment, R dose and pooled compartment (16S R² = 0.360, 0.435 and 0.218; ITS R² = 0.720, 0.712 and 0.304; all p < 0.001); fungal differences also included heterogeneous dispersion. D90 FT-ICR MS profiles described relative DOM molecular variation, but cross-layer residual associations did not survive false-discovery rate correction. Thus, biochar-associated physical and nitrogen changes coincided with microbial and relative DOM restructuring under the tested pot conditions. Because control survival was confounded with treatment, these are observed-group associations rather than pure causal biochar effects. Full article

Leg-spring hysteresis, the mechanical energy dissipated within the force–length loop during ground contact, is a whole-limb, indirect indicator of stretch-shortening cycle (SSC) function. Whether international-level track-and-field and club-level multi-sport athletes differ in hysteresis responses to drop height, and whether hysteresis is associated with jump height, remains unclear. Here, 40 athletes (15 international-level, 25 club-level) performed bilateral (BLJ), dominant-leg (DOM), and non-dominant-leg (NDOM) drop jumps from 0.26 to 0.42 m. Hysteresis and jump height were computed from three-dimensional kinematics (500 Hz) and ground reaction forces. Group × drop-height interactions were significant for hysteresis in all conditions (partial eta-squared, η²p = 0.647, 0.507, 0.466; p < 0.001): international-level athletes became increasingly negative (net active energy contribution) at 0.42 m, whereas club-level athletes became positive (net dissipation). Between-group differences at 0.42 m were large (Cohen’s d = −1.73, DOM; −1.95, NDOM); jump height was also higher in international-level athletes (d = 1.14–1.77). Pooled, hysteresis was associated with jump height (coefficient of determination, R² = 0.44–0.60), although caliber differences inflate this estimate, and within-group associations were weaker. Hysteresis discriminated reactive-jumping capacity beyond jump height alone; because competitive level was confounded with sport discipline and sex, these differences should not be attributed to caliber per se. Full article

Conventional heavy metal remediation technologies are constrained by low efficiency, secondary pollution risks, and limited scalability. Dissolved organic matter (DOM), with its green, cost-effective complexation properties, has become a promising pathway for pollution control. Existing patent bibliometric studies in this field suffer from single-database bias, limited causal quantification of policy impacts, and incomplete depiction of global–local technological heterogeneity. To address these gaps, this study maps the technological innovation landscape of DOM interactions with four typical heavy metals (Cd, Pb, Cu, Zn) during 2004–2024, using a complementary dual-database framework combining Derwent and IncoPat. We integrate a three-dimensional “time–region–technology” analytical framework with interrupted time series analysis (ITSA), after standardized data processing including family deduplication and citation normalization. Cross-validation confirms that China contributes the largest share of global patent output (46.6% in Derwent, 55.0% in IncoPat). Three milestone environmental policies in China exert sequentially intensifying causal effects on patent growth (all p < 0.05), forming a closed-loop mechanism of policy orientation, funding support, technology transfer, and international diffusion. We identify a pronounced global–local technological divergence: global frontier innovation centers on digital basic research, whereas local innovation in China prioritizes engineering applications. Core patents advance the field through cross-domain technology adaptation, and the representative technical paradigm (exemplified by patent CN101168852A) has been industrially validated. These findings provide empirical support for engineering translation and policy optimization in DOM-based heavy metal remediation. Full article

To evaluate how composted agricultural and forestry organic materials function as components of horticultural growing media, a pot experiment was conducted with chrysanthemum (Chrysanthemum morifolium Ramat.) grown in a cinnamon-soil-based medium. The composted material, produced from chestnut shells, chicken manure, and spent mushroom substrate, was incorporated at 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50% (v/v). Water-extractable dissolved organic matter (WE-DOM) was characterized by excitation-emission matrix fluorescence spectroscopy coupled with parallel factor analysis (EEM-PARAFAC), together with the fluorescence index (FI), biological index (BIX), humification index (HIX), and fluorescence regional integration (FRI). Growing-medium physicochemical properties, chrysanthemum traits, and an entropy-weighted comprehensive evaluation were also assessed. Compost amendment increased soil organic matter (SOM), dissolved organic carbon (DOC), total nitrogen, and total phosphorus, lowered pH, and was associated with improved porosity and water-retention characteristics. FI ranged from 1.810 to 2.371 and exceeded 1.9 at amendment rates of 30–35%, suggesting a greater contribution from microbially derived DOM. BIX, HIX, and P_V,n/P_III,n were generally higher in amended treatments than in the control, although their responses were non-monotonic across amendment rates, suggesting greater contributions from recently produced DOM and stronger humification-related fluorescence signals. EEM-PARAFAC resolved five fluorescent components. C1, C2, C3, and C5 were predominantly humic-like, whereas C4 displayed both protein-like and humic-like features. With increasing amendment rate, the relative contributions of C1–C4 generally increased, whereas that of C5 declined, suggesting a shift from the native soil fluorescence profile toward a more complex DOM composition influenced by compost inputs and subsequent biological transformation. Chrysanthemum height, stem diameter, flower number, and biomass were generally more favorable at amendment rates of 30–40%. The entropy-weighted evaluation yielded the highest overall response score at 30%, while the 35% treatment also maintained a high score. Considering WE-DOM fluorescence characteristics, growing-medium properties, and plant performance together, a volumetric amendment rate of 30–35% represents a relatively favorable range for the tested composted material under the present pot-experiment conditions. Full article

To address the scarcity of high-precision control points on planetary surfaces and the accumulated drift of conventional relative-localization methods in deep-space exploration missions, this paper proposes a visual absolute-localization method based on salient-landmark contour matching and centroid-consistency constraints. Absolute localization is defined as estimating the rover position in the landing-site North-East-Down (NED) coordinate system or a map-projection coordinate system, rather than in image-pixel coordinates. Stable natural objects, including dunes and impact craters, are treated as generalized feature points. Local terrain is reconstructed from binocular navigation imagery; LiDAR is additionally used in the ground physical-equivalent experiment for multi-source terrain fusion. Multi-class cross-scale contour matching provides homologous landmark associations, after which centroid consistency aligns the local terrain with the global DOM/DEM reference frame. For ten Tianwen-1/Zhurong camera stations, the mean planar error was 0.458 m and the RMSE was 0.491 m. For five ground-test conditions, the mean planar error was 0.494 m and the RMSE was 0.526 m; all tested errors were below 1 m. Because the in-orbit reference DOM has a ground sampling distance of 1 m/pixel, the in-orbit sub-meter values indicate agreement with the adopted reference products and should not be interpreted as absolute accuracy independent of reference-map uncertainty. The results support the feasibility of natural-landmark-based map localization for future Chang’e and Tianwen missions. Full article

Rice is a globally important staple crop and a major dietary source of inorganic arsenic (As). Compared with upland crops, flooded rice cultivation profoundly alters soil redox conditions, making paddy soils one of the most active agricultural interfaces for As mobilization, transformation, and food-chain transfer. While previous research has primarily focused on total As and inorganic As [As(III)/As(V)], methylated and thiolated As species also carry critical agronomic and health implications. Dimethylarsinic acid (DMA) can accumulate in grain and induce straighthead disease, whereas dimethylmonothioarsenate (DMMTA) shows substantially higher toxicity and uptake potential; DMMTA root uptake can be approximately 10 times higher than DMA, and its straighthead-inducing potency can exceed DMA by more than fivefold. This review synthesizes the sources, biogeochemical transformations, plant uptake, grain accumulation, safety assessment, and management implications of As along the paddy soil–rice–grain continuum. Particular emphasis is placed on how water regimes, redox potential, Fe/Mn/Al oxides, sulfur cycling, dissolved organic matter (DOM), microbial functional genes, and crop genotypes regulate diverse As species. Quantitative evidence indicates that alternate wetting and drying (AWD) can reduce grain total As and inorganic As by medians of 32% and 22%, respectively, but may increase grain cadmium (Cd) by a median of 58%; meanwhile, DMA and DMMTA can account for approximately 10–90% and 1–21% of total grain As, respectively, emphasizing that grain-As risk cannot be evaluated using inorganic As alone. Future research should establish speciation-based monitoring systems for inorganic, methylated, and thiolated As; develop process models linking water regime, Fe/S cycling, microbial transformations, and plant transport; and translate these mechanisms into field decision tools that balance As–Cd risk reduction, crop yield, and rice safety under changing environmental conditions. Full article

Main memory carries data outside the processor’s trust boundary, so commodity systems-on-chip (SoCs) increasingly encrypt it; yet, in-line memory encryption engine itself becomes a differential power analysis (DPA) target whose key, if recovered, unlocks all of dynamic random-access memory (DRAM). We present PACE, a page-adaptive, cache-anchored memory encryption engine for RISC-V that makes nth-order DPA resistance practical and keeps cryptographic latency off the cache eviction critical path. PACE inserts a TileLink adapter between the last-level cache and the memory port and applies, per physical page, one of four policies (plaintext/confidentiality/confidentiality+integrity/+masking-order-d) selected from RISC-V page table bits through a memory-mapped control plane. Confidentiality uses counter mode whose per-line keystream is precomputed during cache residency; integrity is tree-free at the embedded operating point via on-chip counters and tags, with a live split counter block-MAC Bonsai Merkle tree for scale-out. DPA resistance is layered: ISAP-style fresh re-keying caps the data complexity per key at $q\approx 1$, and domain-oriented masking (DOM, d + 1 shares) protects the sole key processing block to order d. We implement PACE in Chisel on a Rocket SoC (Chipyard) and evaluate it with open-source tooling. A deterministic TileLink-level harness proves ciphertext-in-memory and detects tamper/replay/splice, and the live Tier-B engine (DRAM counters and per-line message authentication codes (MACs) plus an on-chip-rooted block-MAC tree) is validated from end to end on full Rocket and BOOM SoCs and on the FPGA; the masked Ascon-p S-box is proven order-d secure (d = 1, 2) under a glitch- and transition-aware model by three independent formal tools (COCO, PROLEAD, and SILVER, the last also deciding the full composability lattice and confirming exact glitch-robust order-2 probing security), with COCO extending the exact verdict to the highest synthesized order d = 3 (secure at probing orders 1–3); a simulated trace correlation power analysis (CPA) recovers the full key from an unprotected core and is defeated by masking, with a mutual information analysis confirming the $N\propto {\sigma }^{2(d+1)}$ trace amplification law. We further realize PACE on field-programmable gate array (FPGA) silicon: the engine plus an on-chip ring oscillator power sensor is placed, routed, timing-closed at 100 MHz, and programmed on a Xilinx XC7Z020, and we drive a fixed-vs-random Test Vector Leakage Assessment (TVLA) campaign read back entirely over a JTAG (Joint Test Action Group). A multi-core configuration and a Linux control-plane driver are likewise validated. Across synthetic access patterns and named application kernels (AES, SHA-256, matrix multiplication, pointer chasing) on both in-order Rocket and out-of-order BOOM, application-level overhead is within measurement noise of plaintext for cache resident workloads (masking, in particular, is cycle-identical to plain confidentiality), and we characterize the cost of each policy, masking order, and re-keying interval, demonstrating side-channel-hardened memory encryption on open RISC-V hardware. Full article

The detection of organic carbon in wastewater is essential for process monitoring and regulatory assessment. Yet conventional chemical oxygen demand (COD) and total organic carbon (TOC) methods remain reagent-dependent, slow, and unsuitable for inline operation. Photoelectrochemical (PEC) sensing based on TiO₂ offers a reagent-free alternative, but its response to wastewater-relevant dissolved organic matter (DOM) and real effluent matrices is still poorly understood. In this study, a TiO₂-based PEC system was systematically evaluated using four representative model compounds—glucose, potassium hydrogen phthalate, L-tryptophan, and urea—covering major fractions typically present in municipal wastewater. For the first time, representative wastewater-associated organic compound classes, conductivity effects, and the transferability of the PEC response to real wastewater effluent were systematically investigated. The photocurrent response showed distinct, highly linear concentration–signal relationships for each substance, suggesting a dominant contribution of surface-associated electronic effects. Conductivity variations across a relevant range had no measurable influence on sensitivity or photocurrent magnitude, indicating that the PEC response is not governed by bulk ionic transport but primarily is an interfacial process at the site of TiO₂. When applied to real wastewater effluent, the sensor exhibited an excellent linear correlation with dilution level (R² = 0.9954), demonstrating a linear response within a defined matrix and an LOD of 1.12 mg L⁻¹ COD. For the investigated model compounds, LOD values ranged from 1.06 to 3.00 mg L⁻¹ COD, while a linear response was maintained up to approximately 80–100 mg L⁻¹ COD. These findings establish TiO₂-based PEC sensing as a promising platform for the reagent-free, online monitoring of organic loads in wastewater treatment. Full article

Lake eutrophication may promote the remobilization of historically buried organochlorine pesticides (OCPs), yet the underlying mechanisms remain unclear. This study reconstructed an 80-year sedimentary record from Lake Qilu to elucidate the linkages between organic matter evolution and OCP dynamics. Sedimentary proxies reveal a transition from oligo-mesotrophic conditions before the 1980s to eutrophic states since the 1990s, with significant increases in total organic carbon (TOC), dissolved organic matter (DOM), and hydrophilic organic matter (HIM), alongside δ¹⁵N enrichment from +2.0‰ to +11.3‰ and a positive δ¹³C shift from −21.7‰ to −14.5‰. The OCP record exhibits three distinct phases: accumulation during the 1940s–1980s, decline following regulatory bans during the 1990s–2000s, and anomalous resurgence during the 2010s–2020s, with ∑Drin (sum of aldrin, dieldrin, and endrin) reaching a historical peak of 10.54 μg/kg in the 2020s. Significant positive correlations were observed between both individual OCP congeners and total OCP classes and total nitrogen (TN), DOM and HIM (p < 0.01 or p < 0.05), indicating that eutrophication-driven algal proliferation releases hydrophilic organic matter, which forms soluble complexes with hydrophobic OCPs, facilitating their upward migration. This study provides direct field evidence for eutrophication-driven OCP remobilization, with important implications for risk assessment of pollutants in eutrophic lakes worldwide. Full article

Background: Recovery between repeated high-intensity efforts is essential to limit fatigue and performance decline in soccer. This study examined the effects of cold water immersion (CWI), foam rolling (FR), and passive recovery during a 15 min interval between two 5 m shuttle run tests (5mSRTs) on physical performance, perceptual responses, and biochemical markers of muscle damage and inflammation. Methods: Fifteen soccer players (age: 22.6 ± 2.03 years) completed passive recovery, FR, and lower-body CWI at 15 °C in a randomized crossover design. Creatine kinase (CK), lactate dehydrogenase (LDH), C-reactive protein (CRP), aspartate transaminase (AST), delayed onset muscle soreness (DOMS), and belief questionnaire scores were assessed before the first 5mSRT and immediately after, and then 24 h, 48 h, and 72 h after the second 5mSRT. Results: Between the first and the second 5mSRT, TD remained unchanged following CWI (p = 0.21), whereas significant decreases were observed following passive recovery (p = 0.025) and FR (p = 0.028). Also, BD decreased after passive recovery (p = 0.03). At 48 h, CWI elicited lower CK (p = 0.01) and LDH (p = 0.003) than passive recovery, whereas FR resulted in lower AST concentrations (p = 0.01). Participants reported higher belief scores following CWI and FR than passive recovery throughout the recovery period (p < 0.05). No between-condition differences were observed for FI, PD, RPE, DOMS, or CRP (all p > 0.05). Conclusions: CWI may help preserve repeated-running performance and attenuate selected markers of muscle damage following repeated high-intensity intermittent exercise in soccer players, whereas FR demonstrated only limited physiological effects. Full article

Coastal riparian zones are important transitional areas for carbon cycling between terrestrial and aquatic ecosystems. However, the associations among litter-derived dissolved organic matter (DOM), soil DOM composition, and soil organic carbon (SOC) fractions across habitats remain insufficiently understood. This study aimed to clarify SOC fraction distribution in woody and herbaceous habitats and evaluate its associations with litter-derived DOM, soil DOM composition, and soil environmental factors in different seasons from a coastal riparian zone. In this study, woody habitats had higher SOC content in March, whereas herbaceous habitats showed greater SOC content in November. Particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) were generally higher in different habitats. MAOC accounted for a large proportion of the measured SOC-related pools and showed a consistent positive association with SOC content. Soil DOM consisted of protein-like and humic-like components, with herbaceous habitats showing a stronger protein-like component and woody habitats showing a stronger humic-like component in March. Woody litter showed greater DOC and DON release potential than herbaceous litter leachates, while litter-derived humic-like DOM was closely associated with a soil humic-like component. The labile SOC pool was mainly associated with vegetation type and electrical conductivity, whereas MAOC was positively associated with soil moisture content and total phosphorus. Overall, the distribution of SOC fractions in coastal riparian habitats is shaped by habitat-specific environmental factors, including vegetative carbon inputs, litter leaching and soil physicochemical properties. This finding is critical for developing targeted management strategies to facilitate SOC accumulation in coastal zones. Full article