Search Results (4,440)

A robust procedure for compensating for inaccuracies caused by 3-D positioning errors in the measurement of the near-field (NF) data required by the non-redundant (NR) spherical near-to-far-field (NtFF) transformations for long antennas is presented in this article. These errors may arise from hardware defects and positioners’ controlling inaccuracies, which may cause the probe to deviate from the intended spherical scan surface and prevent it from reaching the NR sampling points required by either of the two NR representations for long antennas. To account for these errors, the method proceeds through two steps. The first step, called spherical wave correction, compensates for the phase shifts due to radial displacements from the intended scanning sphere. As a result of this correction, the NF samples belong to the intended scanning sphere, but at points different from those required by the adopted NR representation, thus impairing the subsequent NF reconstruction via the optimal sampling interpolation (OSI) algorithm. Such an algorithm enables one to efficiently build the iterative scheme used in the second step, which makes it possible to effectively retrieve the NF samples at the prescribed NR positions. Test results are shown to numerically validate the capability of the developed two-step compensation technique to correct even significant and pessimistic 3-D positioning errors affecting the collection of the NF data. Full article

The Ulungu Depression, located in the northeastern Junggar Basin, adjacent to the Altai Orogenic Belt, exhibits distinctive tectonic relationships and evolutionary mechanisms. Through integrated interpretation of seismic and electromagnetic data, a composite transect was established to characterize the deep-to-shallow geological architecture of the Altai Orogenic Belt–Ulungu Depression system. The tectonic evolution since the Late Paleozoic was reconstructed, revealing three distinct phases: (1) Late Paleozoic peripheral foreland basin development, (2) Mesozoic intracontinental foreland basin formation, and (3) Cenozoic intracontinental foreland basin reactivation. The Late Paleozoic phase records the formation of a peripheral foreland basin in the northeastern Junggar Basin, driven by the Altai-Junggar collision orogeny. During the Mesozoic, intracontinental orogeny along the Altai Belt controlled the development of an intracontinental foreland basin in this region. Paleogene tectonic quiescence facilitated regional subsidence and stable sedimentary deposition. From the Neogene to Quaternary, the Ulungu Depression experienced weak compressional deformation dominated by minor thrust faults, with intermittent regional extensional structures, attributable to the far-field effects of the India-Eurasia collision. This distant tectonic stress primarily localized intracontinental orogeny in the North Tianshan, while the Ulungu Depression, situated farther north, exhibited attenuated strain partitioning. Reconstruction of this multi-phase tectonic evolution provides critical insights into the accretionary orogenic processes of Central Asia. Furthermore, it offers practical implications for hydrocarbon exploration in the Ulungu Depression, particularly regarding structural traps and reservoir distribution patterns. Full article

The calibration accuracy of key weather radar antenna parameters, including beam pointing, beamwidth, and antenna gain, directly affects quantitative precipitation estimation (QPE) and multi-radar network products. Conventional calibration approaches such as external field beacons and far-field tests are often constrained by site conditions and high implementation costs, making them difficult to apply routinely in operational radar networks. To address this limitation, this study proposes a robust solar calibration method for key antenna parameters of weather radars based on a dedicated Volume Coverage Pattern for Sun calibration, hereafter referred to as VCPSun. The proposed method uses a high-density solar scanning strategy with midpoint time alignment and feed-forward control of solar apparent motion. Combined with solar sample identification, propagation path correction, two-dimensional Gaussian surface fitting, and deconvolution of solar-source broadening and scan-smearing effects, the method enables reliability retrieval of beam pointing, beamwidth, and antenna gain. A high-frequency intensive observing experiment was conducted using a China New Generation Weather Radar, model SA-D (CINRAD/SA-D), deployed at the Changsha Meteorological Radar Calibration Center, with independent far-field test results used for validation. The results show that the retention rate of quality-controlled solar samples reached 85.7%, supporting stable reconstruction of the main-lobe power pattern. The retrieved mean beam pointing biases for both polarizations were within ±0.05°. After correction, the relative differences in beamwidth with respect to far-field measurements were respectively 3.26% and 1.52% for the H-polarization azimuth and elevation directions and 2.09% and 1.84% for the V-polarization azimuth and elevation directions, with the overall mean relative difference being less than 3.5%. The antenna gain differences relative to the independent far-field reference values were within 0.2 dB, at −0.062 dB for H-polarization and −0.144 dB for V-polarization. Comparative analysis with historical one-dimensional SunCheck records and an ablation test of the beamwidth correction chain further demonstrate that high-density two-dimensional sampling and physical deconvolution corrections improve the robustness and quantitative accuracy of the solar-based retrieval. These results demonstrate the feasibility of reliable in situ calibration of key antenna parameters for operational weather radars. The proposed method provides a potential technical pathway for in situ quantitative assessment of antenna performance in S-band CINRAD/SA-D radars, although further validation using additional radars and longer observation periods is required prior to network-wide application. Full article

The High Agri Valley (HAV, Southern Italy) comprises the largest onshore oil field in Europe and has both significant geothermal extraction potential and one of the highest seismic hazards in Italy, as demonstrated by the 1857 Mw 7.0 Basilicata earthquake. However, seismic imaging and geological mapping have so far produced insufficient evidence regarding the location of fluid reservoirs and human-induced migration pathways within the HAV’s tectonic structures. Here, a 3D scattering and absorption tomography, proxy for heterogeneities and fluid content, respectively, detects hydrocarbons and potential geothermal resources within the Apulian Platform. Seismic scattering differentiates the low-scattering Irpinia tectonic mélange, which deepens in the center of the valley, from the fractured high-scattering carbonates of the Apulian Platform. Seismic absorption identifies regions of fluid reinjection, as demonstrated by the Costa Molina 2 case study, and reveals the preferred pathways for fluids that induce seismicity due to seasonal variations in the water level of the Pertusillo artificial lake. The integration of scattering and absorption imaging with direct well information, geochemical and hydrological models, could provide a powerful tool for both seismic hazard assessment and the exploration of sustainable energy resources. Full article

Background:Pectobacterium brasiliense-mediated soft rot severely threatens the production of diverse cash crops worldwide and brings severe yield reduction risks. A virulent strain BS1113 was separated from diseased cigar tobacco plants collected in Yunnan, yet its virulence regulatory genes and copper resistance-related genetic background have not been fully analyzed so far. This study aims to decipher the genomic features of BS1113 and clarify its pathogenic and copper-tolerant characteristics via whole-genome sequencing, comparative genomics and indoor phenotype verification. Methods: Hybrid sequencing strategies combining Illumina short reads and PacBio long reads were adopted to obtain the complete circular genome sequence of strain BS1113. Subsequent comparative genomic analysis and multiple phenotypic identification experiments were conducted to characterize its genetic architecture and physiological traits. Results: Genome assembly results showed that the circular chromosome of BS1113 spans 4,916,962 bp with a GC content of 51.96%, which encodes a total of 4369 functional protein-coding genes. Genomic comparison revealed that BS1113 completely lacks the T3SS gene cluster, while it conserves intact T2SS, T6SS and I-F CRISPR-Cas systems; the chromosomal copper resistance operon copRSAB was also detected in this isolate. Pathogenicity tests validated that BS1113 satisfies all criteria of Koch’s postulates on cigar tobacco hosts. In addition, BS1113 displayed prominent tolerance against eight mainstream copper bactericides widely used for tobacco disease management. Conclusions: This research generates the first complete high-quality genome of P. brasiliense isolated from cigar tobacco hosts. The genomic data explain the infection mechanism of this pathogen independent of intact T3SS, and also reveal the genetic basis supporting its persistent survival under long-term copper fungicide pressure in field cultivation environments. Full article

We propose and demonstrate an optical encryption scheme based on cascaded photo-aligned liquid crystal (LC) elements with single-to-multi-image integration. Unlike conventional approaches relying on far-field holography, the proposed method utilizes near-field modulation to improve image capacitance. Theoretical analysis based on a modified Malus’s law provides several optimized orientation-angle distribution phases for optical encryption and decryption with single- or multi-image integrated into the encrypted phase. By employing these phases as LC orientation-angle distributions, corresponding LC elements were fabricated using our single-step exposure photoalignment system. Several independent target images can be reconstructed under different decrypted phases of the second LC element. Both simulations and experiments validate that the proposed scheme achieves a high quality of image reconstruction up to four integrated images. Furthermore, the impacts of LC phase mismatch and spatial misalignment were also investigated, showing that only small mistakes of phases (<20%) and positions (<0.08 mm, <0.2°) can lead to successful image reconstruction, making the system more secure. This work provides a framework for higher-capacity optical encryption and advanced photonic information processing. Full article

To investigate overburden movement and three-zone development under far-field strong dynamic disturbance induced by instability of typical thick and hard overburden in western mining areas, a large-scale two-dimensional physical similarity simulation was conducted using the 11N0201 working face of Maiduoshan Coal Mine as the engineering background. Four test scenarios were designed: a baseline condition, dynamic loading, pressure-relief boreholes, and coupled disturbance. The results show that dynamic loading shortened the first weighting interval of the overburden by 45.5%, while the thicknesses of the caving zone and fracture zone increased to 15 cm and 42 cm, respectively, representing increases of 36.4% and 20.6% relative to the baseline condition. At the fully mined stage, fracture connectivity increased to 45%. A fracture intersection angle of <50°, connectivity of >40%, and abrupt aperture variation can be regarded as empirical semi-quantitative precursor indicators of a dynamic instability tendency in thick and hard overburden. By introducing prefabricated weak planes, roof pre-splitting guided the directional development of fractures and caving. Under coupled disturbance, the thickness of the fracture zone was reduced by 42.9% compared with that under dynamic disturbance alone, and the amplitude of displacement fluctuation decreased by 33.3%. These changes promoted a transition in overburden movement from an “unordered dislocation” state to a controllable state of “dynamic-disturbance-induced, directionally regulated stability”. These findings provide an experimental basis for early warning and prevention of overburden instability under far-field strong dynamic disturbance in western mining areas with thick and hard overburden. Full article

Millimeter-wave (mmWave) radar provides a privacy-preserving and illumination-robust sensing modality for contactless gesture recognition. However, sparse radar point clouds degrade substantially as sensing distance increases: the number of valid detections decreases, echo intensity attenuates, and Doppler-related motion cues become less reliable. Such range-induced degradation leads to a distribution shift between near-range training samples and far-field test samples, making it difficult for models trained at short distances to generalize to unseen longer distances. Existing point-cloud gesture recognition methods usually treat radar detections as generic sparse point sequences and rarely model distance-related point loss, echo attenuation, and physical-attribute unreliability explicitly. This work introduces RPT-Mamba, a range-aware physical token Mamba network for sparse mmWave radar point cloud sequences. RPT-Mamba constructs physical point tokens from spatial coordinates, Doppler velocity, echo intensity, point-level range, and sample-level range information. During training, a range-aware stochastic degradation strategy adaptively removes points and masks dynamic attributes according to the estimated sensing distance, while a context-guided attribute reconstruction objective recovers masked Doppler and intensity attributes from spatial and frame-level context. A bidirectional Mamba temporal encoder then models long-range gesture dynamics over frame tokens. On the public mTransSee dataset, RPT-Mamba achieves 92.09% accuracy and 92.04% Macro-F1 under the random split protocol, and 85.34% accuracy and 84.77% Macro-F1 under a challenging near-to-far protocol, exceeding point-cloud, radar-gesture, Transformer, and Mamba baselines. Full article

The engineering, resource, and financial constraints in space and spacecraft so far have not allowed the incorporation of biological components into a closed-loop bioregenerative life support system (BLSS), despite decades of research. The expected increase in deep-space exploration and planetary bases with limited access to Earth-based resources necessitates the development of self-sustaining hybrid BLSS technology. The created physicochemical systems, together with photosynthetic organisms and bacteria, aim to revitalize the air, produce food, and recycle nutrients and water in mutually beneficial mini-ecosystems. While plants are best in the function of food production and bacteria in waste recycling, the incorporation of microalgae would add immense benefits in optimizing the life support system (LSS) and increasing the degree of closure. Microalgal photobioreactors (PBRs) could perform wastewater treatment (WWT), removing the nitrogen (N) and phosphorus (P) in the human-derived wastewater (WW), and couple it with converting carbon dioxide (CO₂) from the cabin to oxygen (O₂) and food production. As microalgal WWT on Earth is an emerging field with engineering hurdles, power, mass, volume, microgravity fluid dynamics, and other constraints have also prevented their operations in space. However, in space vehicles, there is no need for large upscaling of a laboratory prototype system, and the WW effluent is easier to predict, facilitating microalgal extraplanetary use in comparison to Earth treatment plants. These factors, combined with the qualities of microalgae such as surface-to-volume efficiency, fast growth rate, high yield, and tolerability to WW, etc., have led to many preliminary testbeds, prototypes, and ground demonstrations from space agencies, space centers, and academia, which show promising results. Microalgal participation in space WWT is beyond current operational practice; however, PBRs are on the space agenda, and the scientific community is elaborating the technologies that would allow their successful implementation. Full article

Biosensors are rapidly emerging as a pivotal technology with far-reaching implications in fields such as medical diagnostics, environmental analysis and pharmaceutical research. Among the various biosensing platforms, Graphene Field-Effect Transistor (GFET) biosensors have attracted considerable interest due to their exceptional sensitivity, potential for cost-efficient fabrication, and compatibility with scalable manufacturing processes. This work computationally addresses sensing mechanisms and design strategies associated with GFET-based biosensors, with a focus on the influence of electrolyte gating on device performance, tackling the role of graphene’s quantum capacitance and testing the electrical detection of β2-microglobulin as a case study. Molecular dynamics is used to rationalize the details of the physisorption of a single biomolecule onto the graphene surface, while finite element method simulations are employed to evaluate device sensitivity and figure of merit. Results reveal that incorporating quantum capacitance into the model leads to a Sensitivity-over-FWHM_min figure of merit exceeding 100 L/g being achievable for a β2-microglobulin concentration of 0.001 g/L. These computational outcomes highlight the relevance of quantum-electrostatic effects in GFET biosensor performance and suggest potential routes towards the optimization of graphene-based electronic biodetector engineering. Full article

To address the rockburst hazard caused by overhanging hard roofs and difficult caving during the initial mining period of thick coal seam fully mechanized working faces, this study takes the N4202 fully mechanized top coal caving working face of the Santunzi Coal Mine as the field engineering background. The mined No. 4-1 coal seam has an average thickness of 9.46 m, and its overlying hard roof is composed of medium sandstone and siltstone. A total of 39 hydraulic fracturing boreholes, including type A, type B, type C1/C2, and fan-shaped holes, were deployed, with a designed fracturing depth of 19 m. Three testing means, including a CXK12(B) borehole imaging instrument, a KJ1222 microseismic monitoring system, and on-site roof caving observations, were adopted to comprehensively evaluate the field performance of roof hydraulic fracturing, and the rockburst prevention mechanism was analyzed. The field test results indicate that dense and well-connected fractures are formed after fracturing, with more than 8 fractures per single borehole and a fracture aperture of 0.8–2.2 mm, and the connectivity rate between adjacent fracturing boreholes reaches 92.3%. The initial mining top caving step distance of the working face is reduced to 13.2 m, while the theoretical calculated values are 10 m for the immediate roof and 15.6 m for the main roof. The roof gradually collapses, and the mining pressure is alleviated. During fracturing, the frequency and energy of microseismic events increase by 285% and 230%, respectively, compared to the state before fracturing. In the subsequent mining process, the maximum microseismic energy is only 4.56 kJ, which is far lower than the rockburst critical energy threshold (20 kJ) of this mine. Therefore, no rockburst hazard occurs in the working face. These research findings can provide a practical technical reference for rockburst prevention using hard roof hydraulic fracturing in similar thick coal seam fully mechanized mining faces. Full article

Investigating the relationship between ground motion intensity measures (IMs) and structural responses is fundamental to seismic hazard assessment and performance-based structural design. However, most existing studies are based on the fixed-base assumption, where foundation flexibility is neglected, limiting the understanding of the effects of Soil–Structure Interaction (SSI) on IM–engineering demand parameters (EDPs) correlations. This study systematically evaluates the correlations between various IMs and EDPs while explicitly accounting for SSI effects, with particular emphasis on the influence of ground motion type (near-fault and far-field records). The results indicate that SSI modifies the correlations between IMs and structural responses, although its influence varies among different categories of IMs. For acceleration-based IMs, SSI has a limited impact on their relative effectiveness, preserving their ranking despite moderate changes in correlation coefficients. Velocity-based IMs consistently exhibit the strongest correlations with structural responses; however, their relative performance is strongly dependent on the characteristics of the input ground motions. In contrast, displacement-based IMs demonstrate substantial sensitivity to both soil conditions and ground motion characteristics, resulting in pronounced variability in their predictive capability across different seismic scenarios. These findings highlight the important influence of SSI in IM–EDP correlation analysis and emphasize the necessity of incorporating foundation flexibility when selecting candidate IMs for seismic performance assessment. The results are expected to improve the understanding of IM–response correlations in SSI systems and may help inform the preliminary screening of candidate IMs for performance-based earthquake engineering applications Full article

Wireless-power mobile edge computing, SWIPT-MEC, priority-aware WPT scheduling and swarm resource allocation already solve important parts of the energy-management problem. The novelty of WPT-JCCO is not any one of those elements; it is a single swarm-supervisory feasible set that couples decisions which the three adjacent method classes normally separate. Each epoch-level action jointly selects the robot to charge and one of three physically distinct WPT modalities: far-field radio-frequency, resonant near-field and directional lightwave transfer, together with the SWIPT split, local/edge task placement, CPU frequency, bandwidth and transmit power. Relative to SWIPT-MEC, the formulation adds discrete recipient–modality selection with pose, alignment, blockage and dwell-dependent feasibility. Relative to conventional WPT scheduling, charging is not a separate priority or routing stage but is solved jointly with computation and radio allocation. Relative to swarm resource-allocation methods, energy replenishment is endogenous and an individual minimum-battery constraint protects the weakest robot. A fourth coupling makes the centrally generated resource vector admissible only when the complete sense–compute–actuate age fits the one-second supervisory epoch; otherwise a previously feasible or local-safe action is applied. Nonlinear harvesting, partial offloading, priority scoring and augmented-Lagrangian primal–dual updates are treated as established techniques. This paper derives the continuous block updates, keeps the WPT variables binary through candidate screening, and declares convergence only when stationarity, feasibility, merit-change and binary-hold tests are jointly satisfied. Normalised primal steps are safeguarded by backtracking, dual and penalty updates are bounded, and a local tracking bound plus divergence monitor delimit real-time operation without claiming global mixed-integer optimality or closed-loop motion stability. Numerical evaluation over a 20-robot swarm and 30 Monte Carlo runs shows that WPT-JCCO reduces net energy depletion by 23.8% relative to communication–computation optimisation with static WPT and by 49.7% relative to local-only execution, while increasing task success from 93.5% to 97.3%. A released common-trace comparison shows normalised-cost reductions of 11.1%, 11.3% and 5.8% relative to two-stage WPT+CCO, fixed-SWIPT dynamic offloading and an offline Q-learning scheduler. Convergence and one-factor-at-a-time sensitivity studies further examine swarm size, task load, WPT budget, bandwidth, edge capacity, mobility and channel margin. The headline values remain scoped to the nominal independent-task case; mode-specific RF, near-field and lightwave operating envelopes, robust pose/CSI, WPT-safety and task-DAG extensions are formulated but not presented as hardware-validated results. Full article

During CO₂ pipeline transportation, factors such as third-party interference, pipeline corrosion, and material defects may cause pipeline rupture and CO₂ leakage, posing a threat to the safety of surrounding personnel. Therefore, it is of great significance to study the leakage and dispersion characteristics of CO₂ pipelines. Based on the similarity theory, this study established an offshore platform experimental system, measured the CO₂ concentration variation patterns at different positions on the offshore platform during leakage and dispersion, and identified the influence laws of leakage direction (0°~90°), leakage pressure (1.5~3 MPa), leakage time (1~4 min), and environmental wind speed (0~0.5 m/s) on the leakage and dispersion characteristics of pipeline stations. The results show that when leakage pressure increases, the reading of sensor No. 15 remains unaffected and the maximum concentration is measured at a certain distance from the leakage port; leakage duration has minimal impact; ambient wind speed mainly affects near-field concentration; increasing leakage orifice diameter significantly increases far-field concentration; all sensor readings are zero during vertical leakage; and sensor No. 15 shows the highest reading during 45° upward leakage, while sensor No. 5 shows the highest reading during horizontal leakage. The research results can provide guidance for CO₂ transportation and storage on offshore platforms. Full article

Robust flame stabilization in low-Mach, low-enthalpy supersonic combustors is a core bottleneck for turbine-based combined cycle (TBCC) mode transition. Existing studies mainly focus on single-injector configurations, while the injection angle modulation mechanism for multi-injector cavity flameholders remains unclear under TBCC-relevant conditions. This work experimentally investigated the effects of 30°, 45°, and 90° injection angles on cold-flow mixing, reacting flow topology, and flame stabilization in a Mach 1.6, 660 K dual-injector cavity combustor. Results showed that the overall cold-flow jet penetration capacity in the fully developed far field increased with injection angle following the order of 90° > 45° > 30°. Combustion heat release universally enhanced jet penetration, with a maximum 25% augmentation observed at 30° injection, which attenuated with steepening injection angle. Moreover, flame stability exhibited a non-monotonic trend in the tested dual-injector configuration. Full article