Search Results (1,842)

Large language models (LLMs) such as Chat Generative Pre-Trained Transformer (ChatGPT) are increasingly used across domains, yet their generic training data and propensity for hallucination limit reliability in safety-critical fields like forestry. This paper outlines the conception and prototype of ForestGPT, a domain-specialised assistant designed to support forest professionals while preserving expert oversight. It addresses two looming risks: unverified adoption of generic outputs and professional mistrust of opaque algorithms. We propose a four-level development path: (1) pre-training a transformer on curated forestry literature to create a baseline conversational tool; (2) augmenting it with Retrieval-Augmented Generation to ground answers in local and time-sensitive documents; (3) coupling growth simulators for scenario modeling; and (4) integrating continuous streams from sensors, drones and machinery for real-time decision support. A Level-1 prototype, deployed at Futa Expo 2025 via a mobile app, successfully guided multilingual visitors and demonstrated the feasibility of lightweight fine-tuning on open-weight checkpoints. We analyse technical challenges, multimodal grounding, continual learning, safety certification, and social barriers including data sovereignty, bias and change management. Results indicate that trustworthy, explainable, and accessible LLMs can accelerate the transition to Forestry 5.0, provided that human-in-the-loop guardrails remain central. Future work will extend ForestGPT with full RAG pipelines, simulator coupling and autonomous data ingestion. Whilst exemplified in forestry, a complex, safety-critical, and ecologically vital domain, the proposed architecture and development path are broadly transferable to other sectors that demand trustworthy, domain-specific language models under expert oversight. Full article

The complex interference created by several sources for pipelines has not been sufficiently studied. In this study, four types of interference sources were monitored and analyzed. AC voltage monitoring, DC potential monitoring, current density monitoring, and excavation observation and measurement for test pieces and the decouplers were employed to assess the AC/DC interference of one real buried pipeline in situ. The peak value obtained from the second measurement at Pile 33 decreased from 1341.8 V to 143.7 V, indicating that the 1341.8 V in the first measurement may be caused by a sudden grounding of the electrode, while the 143.7 V may be caused by the normal induced voltage. The most negative DC interference potential between the pipeline and the Cu/CuSO₄ reference electrode was −11.946 V. The most positive DC interference potential between the pipeline and the Cu/CuSO₄ reference electrode was 4.862 V. Pile 3 had a maximum DC current density of 240 mA/m², and Pile 4 had a maximum AC current density of 0.615 A/m². After excavating the test piece at Pile 3, the point with maximum DC interference, there were obvious pitting corrosion characteristics, and the corrosion products were mainly γ-FeOOH and Fe₃O₄. It indicated that the coupling of long-term higher positive DC current density or (DC potential) and short-term higher transient AC voltage or (AC current density) may lead to corrosion. After excavating the test piece at the point with maximum AC interference, namely, Pile 4, there were no significant AC or DC corrosion characteristics. This finding suggested that the combination of long-term low AC current voltage or (low AC current density) and long-term more negative low DC current density or (DC potential) did not result in obvious corrosion. The decouplers in this measurement significantly reduced AC interference above 2 V, but the isolation of transient AC shocks and AC interference below 2 V were not significant. During analysis of AC and DC interference, in addition to considering the value of the interference, the duration time of the interference was also an important factor. Instantaneous sharp peaks cannot represent the long-term average voltage or potential current density. The average value should be used as the main basis for judgement, and the instantaneous value should be used as the secondary basis for judgement. Full article

Numerical simulation and machine learning-based methods are frequently adopted when performing ground movement probabilistic analyses, considering the various uncertainties during shield tunnelling. However, numerical simulation takes time, while machine learning lacks interpretation somehow. New methods fully reflecting mechanisms and taking advantage of field data should be proposed and applied in probabilistic analysis. This study proposes a probabilistic framework from the mechanism and data aspect based on the GAP parameter. Solutions for three components of the GAP parameter are first improved through different methods. Coupling the uncertainty of the input parameters, a probabilistic framework estimating the risks from both mechanistic and data insights is then established. Furthermore, the spatial variability in soft soil is considered in the framework by calculating the equivalent parameters. Through an analysis of a practical case, the results show that the measured data can fall within the 95% confidence interval of the predicted displacement samples. The median of the predicted samples is highly consistent with the measured value, and by considering the spatial variability in soil, the results can be more accurate. As a result, the proposed probabilistic framework is verified as practically applicable when predicting ground movement while considering multiple uncertainties. Full article

By monitoring the alternating interference voltage at the intersections and parallels of gas pipelines with high-speed railways, the alternating voltage between the high-speed railway track supports and the ground, the alternating ground voltage gradient along parallel and perpendicular high-speed railway tracks, and the timing of train passages, the interference patterns caused by high-speed railways on pipelines are analyzed. A numerical model was developed to elucidate interference mechanisms. The conclusions indicate that the interference caused by the parallel and intersecting presence of high-speed railways and pipelines is far greater than that caused solely by the intersection of railways and pipelines. The peak alternating voltage interference on pipelines occurs at the insulation joints of the pipelines, the positions of the pipelines corresponding to the high-speed railway track circuits (AT), and the positions of the pipelines corresponding to the passage of trains. The alternating interference caused by high-speed railway lines on pipelines involves both resistive coupling interference and electromagnetic induction coupling interference, with the latter dominating. Full article

As global urbanization accelerates in ecologically fragile regions, Nature-Based Solutions (NBS) have emerged as a critical paradigm for integrating environmental sustainability with urban resilience. Particularly in hyper-arid environments, the deployment of NBS must navigate unique climatic, hydrological, and socio-political complexities. This paper advances a conceptual framework that synthesizes the International Union for Conservation of Nature’s (IUCN) tripartite typology—protection, sustainable management, and restoration/creation—within a broader systems-oriented governance lens. By engaging with international precedents and context-specific urban dynamics, the study explores how adaptive, multiscale strategies can translate ecological principles into actionable urban design and planning practices. Through a comparative lens and grounded regional inquiry, the research identifies critical leverage points and institutional enablers necessary to operationalize NBS under desert constraints. While highlighting both the structural potential and the contextual limitations of existing initiatives in the Eastern Province of Saudi Arabia, the analysis underscores the necessity of coupling typological coherence with flexible regulatory and participatory mechanisms. Empirical findings from the Saudi case reveal persistent institutional fragmentation, heavy reliance on top-down implementation, and limited hydrological monitoring as key constraints, while also pointing to emerging governance mechanisms under Vision 2030—such as cross-sectoral coordination and pilot participatory frameworks—that can support the long-term viability of NBS in hyper-arid cities. Building on these insights, the study distills a set of strategic lessons that provide clear guidance on hydrological integration, adaptive governance, and socio-cultural legitimacy, offering a practical roadmap for operationalizing NBS in desert urban contexts. Full article

The satellite-derived climatic variables offer extensive spatial and temporal coverage for research; however, their inherent biases can subsequently reduce their accuracy for water balance estimate. This study evaluates the effectiveness of bias correction in improving the Tropical Rainfall Measuring Mission (TRMM) rainfall and the Global Land Data Assimilation System (GLDAS) land surface temperature (LST) data and illustrates their long-term (2000–2019) hydrological assessment. The novelty lies in coupling the bias-corrected climate variables with the Thornthwaite–Mather water balance model as well as land use land cover (LULC) for improved predictive hydrological modeling. Bias correction significantly improved the agreement with ground observations, enhancing the R² value from 0.89 to 0.96 for temperature and from 0.73 to 0.80 for rainfall, making targeted inputs ready to predict hydrological dynamics. LULC mapping showed a predominance of agricultural land (64.5%) in the area followed by settlements (20.0%), forest (7.3%), barren land (6.5%), and water bodies (1.7%), with soils being silt loam, clay loam, and clay. With these improved datasets, the model found seasonal rise in potential evapotranspiration (PET), peaking at 120.7 mm in June, with actual evapotranspiration (AET) following a similar trend. The annual water balance showed a surplus of 523.8 mm and deficit of 121.2 mm, which proves that bias correction not only enhances the reliability of satellite data but also reinforces the credibility of hydrological indicators, with a direct, positive impact on evidence-based irrigation planning and flood mitigation and drought management, especially in data-scarce regions. Full article

This work presents a proof of concept for a short-range high spectral resolution lidar (SR-HSRL) optimized for aerosol characterization in the first kilometer of the atmosphere. The system is based on a compact, high-repetition-rate diode-based fiber laser with a 300 MHz linewidth and 5 ns pulse duration, coupled with an iodine absorption cell. A central challenge in the instrument’s development was identifying a laser source that offered both sufficient spectral resolution for HSRL retrievals and nanosecond pulse durations for high spatiotemporal resolution, while also being compact, tunable, and cost-effective. To address this, we developed a methodology for complete spectral and temporal laser characterization. A two-day field campaign conducted in July 2024 in Tsukuba, Japan, validated the system’s performance. Despite the relatively broad laser linewidth, we successfully retrieved aerosol backscatter coefficient profiles from 50 to 1000 m, with a spatial resolution of 7.5 m and a temporal resolution of 6 s. The results demonstrate the feasibility of using SR-HSRL for detailed studies of aerosol layers, cloud interfaces, and aerosol–cloud interactions. Future developments will focus on extending the technique to ultra-short-range applications (<100 m) from ground-based and mobile platforms, to retrieve aerosol extinction coefficients and lidar ratios to improve the characterization of near-source aerosol properties and their radiative impacts. Full article

We consider a multi-species mixture of interacting bosons, $N_1$ bosons of mass $m_1$, $N_2$ bosons of mass $m_2$, and $N_3$ bosons of mass $m_3$, in a harmonic trap with frequency $\omega$. The corresponding intra-species interaction strengths are ${\lambda }_{11}$, ${\lambda }_{22}$, and ${\lambda }_{33}$, and the inter-species interaction strengths are ${\lambda }_{12}$, ${\lambda }_{13}$, and ${\lambda }_{23}$. When the shape of all interactions is harmonic, the system corresponds to the generic multi-species harmonic-interaction model, which is exactly solvable. We start by solving the many-particle Hamiltonian and concisely discussing the ground-state wavefunction and energy in explicit forms as functions of all parameters, the masses, numbers of particles, and the intra-species and inter-species interaction strengths. We then explicitly compute the reduced one-particle density matrices for all the species and diagonalize them, thus generalizing the treatment by the authors earlier. The respective eigenvalues determine the degree of fragmentation of each species. As an application, we focus on phenomena that do not arise in the corresponding single-species or two-species systems. For instance, we consider a mixture of two kinds of bosons in a bath made by a third kind, controlling the fragmentation of the former by coupling to the latter. Another example exploits the possibility of different connectivities (i.e., which species interacts with which species) in the mixture, and demonstrates how the fragmentation of species 3 can be manipulated by the interaction between species 1 and species 2, when species 3 and 1 do not interact with each other. We highlight the properties of fragmentation that only appear in the multi-species mixture. Further applications are briefly discussed. Full article

Autonomous navigation for unmanned vehicles in complex, unstructured environments remains challenging, especially in GPS-denied or obstacle-dense scenarios, limiting their practical deployment in logistics, inspection, and emergency response applications. To overcome these limitations, this paper presents a tightly integrated air-ground collaborative system comprising three key components: (1) an aerial perception module employing a YOLOv8-based vision system onboard the UAV to generate real-time global obstacle maps; (2) a low-latency communication module utilizing FAST DDS middleware for reliable air-ground data transmission; and (3) a ground navigation module implementing an A* algorithm for optimal path planning coupled with closed-loop control for precise trajectory execution. The complete system was physically implemented using cost-effective hardware and experimentally validated in cluttered environments. Results demonstrated successful UGV autonomous navigation and obstacle avoidance relying exclusively on UAV-provided environmental data. The proposed framework offers a practical, economical solution for enabling robust UGV operations in challenging real-world conditions, with significant potential for diverse industrial applications. Full article

Interferometric signals in space-borne Gravitational Wave Detectors are measured by digital phasemeters. The phasemeter processes signals generated by multiple interferometers, with its primary function being micro-radian level phase measurements. The Science Interferometer is responsible for inter-spacecraft measurements, including relative ranging, absolute ranging, laser communication, and clock noise transfer. Since the scientific interferometer incorporates multiple functions and various signals are simultaneously coupled into the heterodyne signal, establishing a suitable evaluation environment is a crucial foundation for achieving micro-radian level phase measurement during ground testing and verification. This paper evaluates the phase measurement noise of the science interferometer by simulating the heterodyne signal and establishing a test environment. The experimental results show that when the simulated heterodyne signal contains the main beat-note, upper and lower sideband beat-notes, and PRN modulation simultaneously, the phase measurement noise of the main beat-note, upper and lower sideband beat-notes all reach 2π μrad/Hz^1/2@(0.1 mHz–1 Hz), meeting the requirements of the space gravitational wave detection mission. An experimental verification platform and performance reference benchmark have been established for subsequent research on the impact of specific noise on phase measurement performance and noise suppression methods. Full article

Regulatory changes related to the policy of reducing CO₂ emissions from natural gas are leading to an increase in the share of hydrogen in gas transmission and utilization systems. In this context, the impact of the change in composition on thermal radiation zones should be assessed for flaring during startups, scheduled shutdowns, maintenance, and emergency operations. Most existing models are calibrated for hydrocarbon flare gases. This study assesses how the CH₄–H₂ blends affect thermal radiation zones using a developed solver based on the Brzustowski–Sommer methodology with composition-dependent fraction of heat radiated (F) and range-dependent atmospheric transmissivity. Five blends, 0–50% (v/v) H₂, were analyzed for a 90 m stack at wind speeds of 3 and 5 m·s⁻¹. Comparisons were performed at constant molar (standard volumetric) throughput to isolate composition effects. Adding H2 contracted the radiation zones and reduced peak ground loads. Superposition analysis for a multi-flare layout indicated that replacing one 100% (v/v) CH₄ flare with a 10% (v/v) H₂ blend reduced peak ground radiation. Emission-factor analysis (energy basis) showed reductions of 3.24/3.45% at 10% (v/v) H₂ and 7.01/7.44% at 20% (v/v) H₂ (LHV/HHV); at 50% (v/v) H₂, the decrease reached 22.18/24.32%. Hydrogen blending provides coupled safety and emissions co-benefits, and the developed framework supports screening of flare designs and operating strategies as blends become more prevalent. Full article

A combined experimental and theoretical study is carried out on the single-electron capture process in He⁺–He collisions at energies ranging from 0.5 keV/u to 5 keV/u. Using cold target recoil ion momentum spectroscopy, we obtain state-selective cross sections and angular differential cross sections. Within the entire studied energy range, the dominant channel is the electron captured into the ground-state, and the relative contribution of the dominant channel shows a decreasing trend with increasing energy. The angular differential cross sections of ground-state capture exhibit obvious oscillatory structures. To understand the oscillatory structures of the differential cross sections, we also performed theoretical calculations using the two-center atomic orbital close-coupling method, which well reproduced the oscillatory structures. The results indicate that these structures are strongly correlated to the oscillatory structures of the impact parameter dependence of electron probability. Full article

Fluid inclusions, ubiquitously present within fluorite during diagenesis and mineralization, are released as inevitable ionic components in the pulp during mineral crushing and grinding. This study, grounded in geochemistry, combined microstructural analysis, spectroscopy, and X-ray computed tomography (X-CT) to investigate the morphology and petrographic characteristics of fluid inclusions in fluorite minerals. Building on this foundation, inductively coupled plasma optical emission spectrometry (ICP-OES) and ion chromatography (IC) were employed to analyze the release patterns of fluid inclusion components and their impact on fluorite flotation. The results reveal that fluid inclusions within fluorite are predominantly liquid-rich, two-phase (vapor-liquid) inclusions, exhibiting a spatial distribution density as high as 14.1%. Furthermore, fluid components are released during fluorite grinding, particularly homonymous Ca²⁺ ions, which significantly influence fluorite flotation behavior. Low concentrations of Ca²⁺ can activate fluorite flotation, whereas high concentrations of Ca²⁺ consume the collector (sodium oleate) in solution through competitive adsorption. This competition inhibits the adsorption of sodium oleate onto the fluorite mineral surface. The findings of this research provide theoretical support for in-depth studies on fluid inclusions in minerals and their effects on mineral flotation behavior, thereby facilitating the clean and efficient recovery of strategic fluorite mineral resources. Full article

The on-orbit geometric calibration accuracy of high-resolution space cameras directly affects the application value of Earth observation data. Conventional on-orbit geometric calibration methods primarily rely on ground calibration fields, making it difficult to simultaneously achieve high precision and real-time monitoring. To address this limitation, we, in collaboration with Tsinghua University, propose a high-precision, real-time, on-orbit geometric calibration system based on active optical monitoring. The proposed system employs reference lasers to integrate the space camera and the star tracker into a unified optical system, enabling real-time monitoring and correction of the camera’s exterior orientation parameters. However, during on-orbit operation, the space camera is subjected to a complex thermal environment, which induces thermal deformation of optical elements and their supporting structures, thereby degrading the measurement accuracy of the geometric calibration system. To address this issue, this article analyzes the impact of temperature fluctuations on the focal plane, the reference laser unit, and the laser relay folding unit and proposes athermalization design optimization schemes. Through the implementation of a thermal-compensated design for the collimation optical system, the pointing stability and divergence angle control of the reference laser are effectively enhanced. To address the thermal sensitivity of the laser relay folding unit, a right-angle cone mirror scheme is proposed, and its structural materials are optimized through thermo–mechanical–optical coupling analysis. Finite element analysis is conducted to evaluate the thermal stability of the on-orbit geometric calibration system, and the impact of temperature variations on measurement accuracy is quantified using an optical error assessment method. The results show that, under temperature fluctuations of 5 °C for the focal plane and the reference laser unit, 1 °C for the laser relay folding unit, and 2 °C for the star tracker, the maximum deviation of the system’s measurement reference does not exceed 0.57″ (3σ). This enables long-term, stable, high-precision monitoring of exterior orientation parameter variations and improves image positioning accuracy. Full article

The ground small-loop transient electromagnetism (TEM) provides a basis for detecting shallow underground space. However, the strong primary field interference from the transmitting coil to the receiving coil, along with the transition process of the receiving coil, can cause serious distortion of the early secondary field signals. This leads to the loss of effective shallow underground information. In this paper, we utilize the eccentric self-compensating structure to weaken the primary field interference. Aiming at the current position sensitivity of the eccentric structure, we propose a statistical method to realize the robustness analysis of the eccentric structure and find the optimal eccentric position where the primary field coupling between the transmitting and receiving coil is approximated to be zero. To address the impact of the coil transition process, a double receiving coils structure is proposed. This ensures that the number of turns, the secondary field flux and the secondary field response strength in the single receiving coil structure remain unchanged. Compared with the conventional eccentric structure of a single receiving coil, the bandwidth of the receiving coil sensor was increased from 103.5 kHz to 218.3 kHz, and the Signal-to-Noise Ratio (SNR) of the measured early secondary field signals improved from 18.5 to 27.9, representing a 50.81% increase in SNR. This study not only reduces primary field interference but also reduces the impact of the coil transition process, thereby capturing more early secondary field signals and enhancing the shallow detection resolution of the ground TEM. Full article