Search Results (1,638)

Mining affects groundwater and surface water both during an active mining operation and after its termination. Continuous monitoring and both quantitative and qualitative assessment of water dynamics are crucial for the sustainable management of the mining and post-mining environment. This paper provides an extensive overview of water in the mining industry and of remote sensing methods for surface water monitoring. Moreover, selected spectral water indices are compared to assess their performance and usefulness in surface water monitoring. The Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), and Modified Normalized Difference Water Index (MNDWI) are applied to different case study areas affected by mining-induced multitemporal surface water changes. All the selected indices were found useful as proxies for surface water identification; however, their effectiveness and accuracy varied in subsequent case studies. Full article

The adverse propagation environment in underground coal mine tunnels caused by enclosed spaces, rough surfaces, and dense scatterers severely degrades reliable wireless signal transmission, which further impedes the deployment of IoT applications such as gas monitors and personnel positioning terminals. However, the conventional power enhancement solutions are infeasible for the underground coal mine scenario due to strict explosion-proof safety regulations and battery-powered IoT devices. To address this challenge, we propose singular value decomposition-based Lagrangian optimization (SVD-LOP) to minimize transmit power at the mining base station (MBS) for IRS-assisted coal mine wireless communication systems. In particular, we first establish a three-dimensional twin cluster geometry-based stochastic model (3D-TCGBSM) to accurately characterize the underground coal mine channel. On this basis, we formulate the MBS transmit power minimization problem constrained by user signal-to-noise ratio (SNR) target and IRS phase shifts. To solve this non-convex problem, we propose the SVD-LOP algorithm that performs SVD on the channel matrix to decouple the complex channel coupling and introduces the Lagrange multipliers. Furthermore, we develop a low-complexity successive convex approximation (LC-SCA) algorithm to reduce computational complexity, which constructs a convex approximation of the objective function based on a first-order Taylor expansion and enables suboptimal solutions. Simulation results demonstrate that the proposed SVD-LOP and LC-SCA algorithms achieve transmit power peaks of $20.8\mathrm{dBm}$ and $21.4\mathrm{dBm}$, respectively, which are slightly lower than the $21.8\mathrm{dBm}$ observed for the SDR algorithm. It is evident that these algorithms remain well below the explosion-proof safety threshold, which achieves significant power reduction. However, computational complexity analysis reveals that the proposed SVD-LOP and LC-SCA algorithms achieve $\mathcal{O}\left(N^3\right)$ and $\mathcal{O}\left(N^2\right)$ respectively, which offers substantial reductions compared to the SDR algorithm’s $\mathcal{O}\left(N^7\right)$. Moreover, both proposed algorithms exhibit robust convergence across varying user SNR targets while maintaining stable performance gains under different tunnel roughness scenarios. Full article

We report a rapid aqueous method for synthesizing monodisperse gold nanoparticles (AuNPs), employing 2-propynylamine as both an intrinsic reducing agent and a surface-stabilizing ligand. This self-mediated process—achieved in a single step—yields spherical AuNPs with an average diameter of 4.0 ± 1.0 nm and a well-defined localized surface plasmon resonance band centered at 520 nm. Acting as a bifunctional molecule, 2-propynylamine simultaneously reduces HAuCl₄·3H₂O to elemental gold and passivates the nanoparticle surface through coordination via the amine group, while preserving a terminal alkyne (–C≡CH) functionality. This reactive moiety remains exposed and chemically accessible, enabling post-synthetic modification through Cu(I)-catalyzed azide–alkyne cycloaddition. Control experiments using alternate milling times and vial composition confirmed the essential role of 2-propynylamine in mediating both reduction and surface functionalization. The resulting alkyne-functionalized AuNPs serve as versatile “click-ready” platforms for bioconjugation, sensing, and advanced material assembly. Overall, this scalable, green approach eliminates the need for external reducing or capping agents and provides a modular route to chemically addressable nanomaterials with tunable surface reactivity. Full article

Advancing catalysts for low-temperature NH₃-SCR enhances their viability as a terminal flue gas denitration solution across diverse operating regimes. A high-performance, hydrothermally stable catalyst for low-temperature SCR was synthesized by depositing MnO_x onto MgAlO_x composite oxide supports. These supports, featuring varied Mg/Al ratios, originated from layered double hydroxide (LDH) precursors. The obtained catalyst with the Mg/Al ratio of 2 (Mn/Mg₂AlO_x) possesses relatively high concentrations of active oxygen species (O_α) and Mn⁴⁺ and exhibits remarkable catalytic performance. The Mn/Mg₂AlO_x catalyst exhibits a wide operating temperature range (100–300 °C) for denitration, achieving over 80% NO_x conversion, along with robust water resistance. The temperature-programed surface reactions and NO oxidation reactions are performed to elucidate the promoting effect of water on N₂ selectivity, which is not only due to inhibition of catalyst oxidation capacity at high temperature but also is related to the competing adsorption of water and NH₃. In situ DRIFTS analysis confirmed that the NH₃-SCR mechanism over Mn/Mg₂AlO_x adheres to the Eley–Rideal (E–R) pathway. These findings highlight the significant promise of Mn/MgAlO_x catalysts for deployment as downstream denitration units within exhaust treatment systems. Full article

Aiming at the control performance degradation of permanent magnet synchronous motor (PMSM) drive systems caused by uncertainties of internal and external disturbances, a robust control algorithm integrating an improved fast terminal sliding mode (IFTSM) surface with a novel adaptive reaching law (NARL) is proposed. A dynamic model of PMSM with disturbances is established, and an improved fast terminal sliding mode surface is designed. By introducing nonlinear terms and error derivative feedback mechanisms, the finite-time rapid convergence of system states is achieved, while solving the singularity problem of traditional terminal sliding mode control. Combined with the novel adaptive reaching law strategy, a state-dependent gain adjustment function is used to dynamically optimize the balance between reaching speed and chattering, enhancing the smoothness of the system′s dynamic response. Through the synergy of the finite-time convergence characteristic of the improved sliding mode surface and the novel adaptive reaching law, the proposed algorithm significantly enhances the system′s anti-interference capability against load mutations and parameter time variations. Experiment results demonstrate that under complex working conditions, the algorithm achieves superior speed tracking accuracy and current stability, providing a control solution with strong anti-interference capability and fast response for PMSM speed control systems. Full article

This research proposes a non-penetration lap welding process for joining T2 copper power module terminals in high-frequency and high-power electronic applications, using a hybrid laser system combining a 445 nm blue diode laser and a 1080 nm fiber laser. The composite laser beam, formed by coupling a circular blue laser beam with a spot-shaped fiber laser beam, was oscillated along circular, sinusoidal, and 8-shaped trajectories to control weld geometry and joint quality. Results indicate that all trajectories produced U-shaped weld cross-sections with smooth toe transitions and good surface quality. Specifically, the circular trajectory provided uniform energy distribution and stable weld formation; the 8-shaped trajectory achieved a balanced width-to-depth ratio; and the sinusoidal trajectory exhibited sensitivity to welding speed, often resulting in uneven fusion width. Increased welding speed promoted grain refinement, but excessive speed led to porosity and poor surface quality in both 8-shaped and sinusoidal trajectories. Oscillating laser welding facilitated equiaxed grain formation, with the circular and 8-shaped trajectories yielding more uniform microstructures. The circular trajectory maintained consistent weld dimensions and hardness distribution, while the 8-shaped trajectory exhibited superior tensile strength. This work highlights the potential of circular and 8-shaped trajectories in hybrid laser welding for regulating weld microstructure, enhancing mechanical performance and ensuring weld stability. Full article

In the present work we investigate by first principles calculations the structural, electronic, and optical properties of alkyl, 1-alkenyl and 1-alkynyl C₈ moieties chemisorbed on hydrogen-terminated silicon nanowire oriented along the ⟨112⟩ direction. Our results disclose how the nature of the carbon–carbon bond contiguous to the Si surface influences the behavior of the system. While 1-alkynyl groups exhibit the strongest Si–C bonding, it is 1-alkenyl functionalization that induces the most significant enhancement in optical absorption within the visible range due to charge transfer. The charge transferred from the nanowire to the moiety confirms the electronic coupling of the two systems. We found that the highest occupied molecular orbital of the 1-alkenyl moiety lies only 0.3 eV below the valence band edge of the hydrogen-terminated silicon nanowire, enabling new low-energy optical transitions which are absent in both the unmodified silicon nanowire and the isolated molecule. These findings demonstrate a synergistic effect of functionalization. Our study provides valuable insights into the design of functionalized silicon nanostructures with tailored optical properties, with potential implications for applications in sensing, photonics, and energy conversion. Full article

In the present study, a new Ganoderma sp. (ZHM1939) was collected from Lincang, Yunnan, China, and described on the basis of morphological characters and multigene phylogenetic analysis of rDNA-ITS, TEF1α and RPB2 sequences. This fungus is characterized by the exceptionally large basidiomata, oval shape, a pileus measuring 63.86 cm long, 52.35 cm wide, and 21.63 cm thick, and a fresh weight of 80.51 kg. The skeleton hyphae from the basidiocarp are grayish to grayish-red in color, septate, and 1.41–2.75 μm in diameter, with frequently dichotomous branched and broadly ellipsoid basidiospores. The basidiospores are monocellular, ellipsoid, with round ends or one slightly pointed end, brown–gray in color, and measured 6.52–10.26 μm × 4.68–7.17 μm (n = 30). When cultured for 9 days at 25 ± 2 °C on PDA, the colony was white, ellipsoid or oval, with slightly ragged edges, measured Φ58.26 ± 3.05 mm (n = 5), and the growth rate = 6.47 mm/day; prosperous blast-spores formed after culturing for 21 days, making the colony surface powdery-white. The mycelia were septate, hyaline, branching at near-right angles, measured Φ1.28–3.32 μm (n = 30), and had some connections. The blast-spores were one-celled, elliptic or barley-seed shaped, and measured 6.52–10.26 μm × 4.68–7.17 μm (n = 30). Its rDNA-ITS, TEF1α and RPB2 sequences amplified through PCR were 602 bp, 550 bp and 729 bp, respectively. Blast-n comparison with these sequences showed that ZHM1939 was 99.67–100% identical to related strains of Ganoderma mutabile. A maximum likelihood phylogenic tree using the concatenated sequence of rDNA-ITS, TEF1α and RPB2 was constructed and it showed that ZHM1939 clustered on the same terminal branch of the phylogenic tree with the strains Cui1718 and YUAN 2289 of G. mutabile (Bootstrap support = 100%). ZHM1939 could grow on all the 15 original inoculum substrates tested, among which the best growth was shown on substrate 2 (cornmeal 40 g, sucrose 10 g, agar 20 g), with the fastest colony growth rate (6.79 mm/day). Of the five propagation substrates tested, substrate 1 (wheat grains 500 g, gypsum powder 6.5 g and calcium carbonate 2 g) resulted in the highest mycelium growth rate (7.78 mm/day). Among the six cultivation substrates tested, ZHM1939 grew best in substrate 2 (cottonseed hulls 75 g, rice bran 12 g, tree leaves 5 g, cornmeal 5 g, lime powder 1 g, sucrose 1 g and red soil 1 g) with a mycelium growth rate of 7.64 mm/day. In conclusion, ZHM1939 was identified as Ganoderma mutabile, which is a huge mushroom and rare medicinal macrofungus resource. The original inoculum substrate 9, propagation substrate 1 and cultivation substrate 2 were the most optimal substrates for producing the original propagation and cultivation inocula of this macrofungus. This is the first report on successful growing conditions for mycelial production, but basidiocarp production could not be achieved. The results of the present work establish a scientific foundation for further studies, resource protection and application development of G. mutabile. Full article

To address the issues of external unknown disturbances and roll motion in the tracking control of underactuated unmanned surface vehicle (USV) formation, a cooperative formation control method based on nonlinear model predictive control (NMPC) algorithm and finite-time disturbance observer is proposed. Initially, a tracking error model for the USV formation is established within a leader–follower framework, utilizing a four-degree-of-freedom (4-DOF) dynamic model to simultaneously account for roll motion and trajectory tracking. This error model is then approximately linearized and discretized. To mitigate the initial non-smoothness in the desired trajectories of the follower USVs, a tracking differentiator is designed to smooth the heading angle of the leader USV. Thereafter, a quasi-infinite horizon NMPC algorithm is developed, in which a terminal penalty function is constructed based on quasi-infinite horizon theory. Furthermore, a finite-time disturbance observer is developed to facilitate real-time estimation and compensation for unknown marine disturbances. The proposed method’s effectiveness is validated both mathematically and in simulation. Mathematically, closed-loop stability is rigorously guaranteed via a Lyapunov-based proof of the quasi-infinite horizon NMPC design. In simulations, the algorithm demonstrates superior performance, reducing steady-state tracking errors by over 80% and shortening convergence times by up to 75% compared to a conventional PID controller. These results confirm the method’s robustness and high performance for complex USV formation tasks. Full article

Co-electrolysis of CO₂ and H₂O offers a promising route for efficient and controllable syngas production from greenhouse gases and water. However, the atomic-scale reaction mechanism remains elusive, especially on complex oxide surfaces. In this study, we employ density functional theory (DFT) to investigate the adsorption and activation of CO₂ and H₂O on the FeMoO-terminated (001) surface of Sr₂Fe_1.5Mo_0.5O₆ (SFM), a double perovskite of growing interest for solid oxide electrolysis. Our results show that CO₂ strongly interacts with surface lattice oxygen, adopting a bent configuration with substantial charge transfer. In contrast, H₂O binds more weakly at Mo sites through predominantly electrostatic interactions. Co-adsorption analyses reveal a bidirectional interplay: pre-adsorbed H₂O enhances CO₂ binding by altering its adsorption geometry, whereas pre-adsorbed CO₂ weakens H₂O adsorption due to competitive site occupation. This balance suggests that moderate co-adsorption may facilitate proton–electron coupling, while excessive coverage of either species suppresses activation of the other. Bader charge analysis, charge density differences, and projected density of states highlight the key role of Fe/Mo–O hybridized states near the Fermi level in mediating surface reactivity. These results, obtained for a perfect defect-free surface, provide a theoretical benchmark for disentangling intrinsic molecule–surface and molecule–molecule interactions, and offer guidance for designing high-performance perovskite electrocatalysts for CO₂ + H₂O co-electrolysis. Full article

The electrochemical decomposition of HI_x solution presents a promising alternative to overcome the challenges associated with HI thermal decomposition in the sulfur–iodine (S-I) cycle. In this study, constant current electrolysis and LSV tests were carried out for HI_x solution using an H-type electrolyzer at different current densities and anode solution compositions. The results showed that during the process of HI electrolysis, the dominant factor of voltage variation gradually changed from electrochemical polarization to ohmic polarization as the current density increased. When the I₂ concentration in the HI solution approached saturation, a voltage step occurred in the constant current electrolysis, reaching a maximum amplitude of 127.69%. The analysis indicated that the voltage step was related to the I₂ deposition on the electrode and PEM, which led to the simultaneous increase in activation polarization and ohmic polarization overpotential. The increase in I₂ concentration decreased the limiting diffusion current density; I₂ supersaturation led to the formation of an insoluble iodine film on the electrode surface, ultimately terminating the electrochemical reaction. This study provides guidance for the development of HI_x solution electrolysis technology for hydrogen production. Full article

Breast cancer (BC) is a major cause of cancer-related mortality. Mortalin and Vimentin—two proteins implicated in BC progression and metastasis—have been identified as binding partners of the Secretion Modification Region (SMR) peptide from the HIV Nef protein. These interactions disrupt exosome release and offer novel therapeutic strategies. This study investigates the binding interactions between the SMR peptide, Mortalin, and Vimentin using surface plasmon resonance (SPR), co-immunoprecipitation (Co-IP), and Western blot assays. We also map the SMR binding sites on Mortalin through scanning peptide mapping and then identify a similar site on the Vimentin protein. Based on these data, we propose that the SMR peptide and its analogs interact with specific amino acid sequences in Mortalin and Vimentin, thereby disrupting cellular processes essential for Epithelial–Mesenchymal Transition (EMT) and tumor progression. SPR analysis revealed that the Nef protein exhibited the highest binding affinity to Vimentin (KD = 0.75 ± 1.1 nM) and Mortalin (KD = 3.16 ± 0.03 nM). The SMRwt peptide also demonstrated direct binding to both proteins with micromolar affinities (KD = 6.63 ± 0.74 µM for Vimentin; KD = 20.73 ± 2.33 µM for Mortalin), though the binding affinity was weaker than the full Nef protein. Co-IP experiments using MDA-MB-231, MCF-7, and BT474 BC cell lines confirmed that SMRwt, but not SMRmut, co-immunoprecipitated with Mortalin. Western blot analysis validated these interactions. Further, Mortalin peptide #56, derived from the substrate-binding domain, did not bind the SMR domain or inhibit Nef function. In contrast, peptides #61 and #62 from the C-terminal domain of Mortalin bound the SMR domain and effectively inhibited Nef activity. Notably, Mortalin peptide #61 inhibited SMRwt binding to both Mortalin and Vimentin, disrupting complex formation on the SPR sensor chip. These findings suggest that specific Mortalin-derived peptides can block SMR interactions, offering a potential therapeutic mechanism. Full article

In this study, xanthan gum (XG)-modified coal-fly-ash-based cementitious materials were synthesized to realize the resource utilization of coal fly ash and to develop a low-carbon emission cementitious sealing material that can substitute cement-based sealing material to prevent coal fires. The optimal formulation for coal-fly-ash-based mining cementitious sealing material was developed using response surface methodology based on Box–Behnken Design. The optimized formulation was obtained with a coal fly ash-to-precursor ratio of 0.65, alkali-activator modulus of 1.4, and alkali-activator dosage of 7.5%. Under the optimal conditions, the initial and final setting time were 26 min and 31 min, respectively, fluidity was 245 mm, and the 7-day compressive strength approached 36.60 MPa, but there were still thermal shrinkage and cracking phenomena after heating. XG was then introduced to improve the thermal shrinkage and cracking of coal-fly-ash-based cementitious materials. Incorporating 1 wt.‰ XG was found to decrease the fluidity while maintaining the setting time and increasing the 1-day and 7-day compressive strength by 15.44% and 1.97%, respectively. The results demonstrated that the gels generated by XG cross-linking and coordinating with Al³⁺/Ca²⁺ were interspersed in the original C(N)-A-S-H gel network, which not only made the 1 wt.‰ XG modified coal-fly-ash-based cementitious material show minor expansion at ambient temperatures, but also improved the residual compressive strength, thermal shrinkage resistance and cracking resistance in comparison to unmodified cementitious material. However, due to the viscosity of XG and the coordination of Al³⁺ and non-terminal carboxyl groups in XG breaking the gel network, XG incorporation should not exceed 1 wt.‰ as the compressive strength and fluidity are decreased. Full article

The skin protects the body from damaging external stressors. The function of its outermost compartment, the epidermis, depends on high rates of protein synthesis and the production of protective molecules, both requiring amino acids as precursors. Conversely, the degradation of the epidermal barrier protein filaggrin releases free amino acids. Here, we review the epidermal amino acid metabolism, focusing on the metabolism of histidine, arginine and tyrosine, which are subjected to epidermal cell-specific control mechanisms. Histidine and arginine are metabolized by enzymes that are transcriptionally upregulated during terminal differentiation of keratinocytes, while tyrosine is specifically metabolized in melanocytes. Arginase converts arginine into ornithine and urea. While ornithine is decarboxylated to putrescine, a regulator of cellular proliferation, urea contributes to the moisturization of the skin surface. Histidase, also known as histidine ammonia lyase, converts histidine into urocanic acid (UCA) and ammonia. UCA is the main ultraviolet-absorbing molecule of the cornified layer of the epidermis, serving as a natural sunscreen of human skin. In melanocytes, tyrosinase initiates the polymerization of tyrosine to melanin, the main skin pigment that absorbs both visible light and ultraviolet radiation. The current evidence indicates that the metabolism of histidine, arginine, tyrosine and other amino acids critically influences normal and diseased skin. Full article

As the terminal reservoir of the South-to-North Water Diversion’s Eastern Route, Dongping Lake is critical for safeguarding the northern water supply. Analysis of 33 water–sediment sites revealed the following. (1) Waterborne heavy metals (HMs) below WHO limits, confirming the good water quality. (2) Sediment HM enrichment exceeding background levels, with Cd posing high ecological risk (mean E_r = 135), and moderate overall pollution. (3) Speciation showed V, Cr, Co, Ni, Cu, Zn, and Pb predominantly in residual fractions, while Cd exhibited high bioavailability and Pb was in reducible state. Ecological risk assessment indicated that V and Cr tend not to cause environmental pollution; Co, Ni, Cu, Zn, and Pb only cause slight pollution; and Cd causes serious point-source pollution. The carcinogenic risk of surface sediments to children is not negligible. (4) Source apportionment identified industrial emissions as the primary HM contributors, with Cd deriving from agricultural runoff (phosphate fertilizers) and industrial discharges. This study offers valuable baseline information for water quality management in mega-water-transfer projects, directly supporting the Jiaodong Main Line and Yellow River Crossing operations. Full article