Search Results (6,585)

This study investigated the impact of cobalt/nickel-silicate loadings on graphitic carbon nitride at 10% and 20% doses, designated (CoNiSi-10) and (CoNiSi-20), for the removal of ciprofloxacin (CPF), a hazardous, bioaccumulative antibiotic. The synthesized composites were characterized in detail using SEM, EDX, TEM, N₂ adsorption–desorption, XRD, and FTIR techniques. The CoNiSi-10 and CoNiSi-20 exhibited CPF q_t values of 64 and 107 mg g⁻¹, respectively, which were consistent with the surface area results. Adsorption kinetics indicated that CPF uptake on CoNiSi-10 and CoNiSi-20 fitted the Lagergren model, with the liquid-film and intraparticle-diffusion mechanisms co-governing CPF sorption. The isotherm investigations indicated CPF adsorption on CoNiSi-10 and CoNiSi-20 aligned with the Langmuir model, suggesting a homogeneous surface, while the Dubinin-Radushkevich results primarily indicated physisorption-based CPF removal. The thermodynamic analyses supported the physisorption outcome and indicated that CPF sorption onto CoNiSi-10 and CoNiSi-20 was endothermic. A five-cycle reusability test yielded average efficiencies of 94% and 96% for CoNiSi-10 and CoNiSi-20, respectively, and an after-sorption analysis indicated their stability and robustness. The ease of synthesis and excellent sorption performance may nominate CoNiSi-10 and CoNiSi-20 as promising adsorbents for treating pharmaceutically contaminated wastewater. Full article

Quinoline derivatives constitute a privileged class of nitrogen-containing heterocycles with extensive applications in medicinal chemistry, agrochemicals, materials science, and functional organic materials. Owing to their broad biological and industrial relevance, the development of efficient, selective, and sustainable synthetic methodologies for quinoline construction remains an active area of research. This review provides a comprehensive overview of recent advances in quinoline synthesis, with particular emphasis on catalytic strategies aligned with the principles of green and sustainable chemistry. Classical transformations, including the Friedländer, Skraup, and Povarov reactions, are revisited in the context of modern catalytic developments that improve reaction efficiency, substrate scope, selectivity, and environmental compatibility. Special attention is devoted to homogeneous and heterogeneous catalytic systems based on both platinum-group and earth-abundant transition metals, highlighting the growing importance of borrowing-hydrogen and acceptorless dehydrogenative coupling methodologies. Recent progress in nanocatalysis, photocatalysis, multicomponent reactions, ionic-liquid-mediated transformations, and metal-free protocols is also critically discussed. Furthermore, solvent-free processes, microwave-assisted synthesis, and recyclable catalytic systems are examined as practical approaches toward minimizing waste generation and energy consumption. Mechanistic aspects, catalytic design principles, substrate limitations, and sustainability metrics are evaluated throughout the review to provide a critical perspective on current methodologies. Collectively, the advances summarized herein demonstrate the rapid evolution of quinoline synthesis toward more atom-economical, environmentally benign, and operationally efficient processes, while also identifying future opportunities for the development of next-generation catalytic platforms for quinoline-based heterocycle construction. Full article

New lacunary Keggin-type polyoxometalate salts with the formula Cs₅PMMo₁₁(H₂O)O₃₉ (M = Cu, Zn) were synthesized via the inorganic solution condensation method. X-ray diffraction and FT-IR spectroscopy confirmed the preservation of the Keggin structure. The surface morphology and elemental composition were characterized using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. Thermal analysis, performed by differential scanning calorimetry coupled with thermogravimetry, demonstrated a significant enhancement in thermal stability upon the incorporation of the transition metals into the heteropolyacid framework. Specifically, the substitution of protons by cesium and of molybdenum by copper or zinc positively influenced the crystallographic configuration of the salts, raising their thermal resistance (up to 526 °C). Furthermore, optical and dielectric measurements revealed promising electronic properties in the synthesized lacunary salts. Notably, the compound Cs₅PZnMo₁₁(H₂O)O₃₉ exhibited a substantially increased dielectric constant at low frequency, underscoring the synergistic effect of zinc addition on its dielectric performance. Full article

Platinum ditelluride (PtTe₂) is an emerging topological semimetal with intriguing optoelectronic properties. Scalable and controllable growth techniques are fundamental for its technological exploitation. Here, we synthesize large-area PtTe₂ films by tellurization of pre-deposited platinum layers. By selectively modifying the tellurization parameters, we demonstrate the possibility of controlling the layer orientation of tellurized films and of introducing microscopic corrugation in the PtTe₂ film. The first result is obtained by increasing the thermal budget of the process, which changes PtTe₂ preferential crystalline orientation from (001) to (1−13)/(103) growth directions. The latter result is achieved by modifying the heating rate of the process at a fixed growth temperature equal to 550 °C. From the Raman analysis of a wrinkled sample, we find the coexistence of tensile and compressive strains depending on the corrugation site. The demonstrated control over grain orientation and microscopic corrugation provides a powerful strategy to tailor the structural and strain landscape of topological semimetals, providing a robust platform for strain engineering. Full article

The explosive demand for flexible wearable and portable devices imposes stringent requirements on the mechanical, energy storage, and sensing properties of functional materials. Although two-dimensional (2D) transition metal carbides and nitrides (MXene) possess high conductivity and pseudocapacitance, their severe self-restacking and intrinsic brittleness restrict their practical applications. Herein, a facile vacuum filtration and hot-pressing densification strategy is proposed to fabricate nacre-inspired MXene-based films. By incorporating one-dimensional (1D) high-aspect-ratio TEMPO-oxidized cellulose nanofibrils (TOCNFs), the self-restacking of MXene is effectively suppressed. The optimal M20F5 composite film exhibits a coordinated electromechanical balance, maintaining an electrical conductivity of 1.07 × 10⁶ S m⁻¹ while enduring 2124 folding cycles. For energy storage, the assembled symmetric supercapacitor delivers a specific capacitance of 828.92 F g⁻¹ at 0.5 mA cm⁻² and maintains an energy density of 13.75 Wh kg⁻¹ at a power density of 9500 W kg⁻¹. Furthermore, acting as a piezoresistive sensor, the film achieves reliable detection, spanning from bimodal gait recognition to subtle physiological pulses. This work establishes a viable material design strategy for next-generation supercapacitors and intelligent wearable systems. Full article

Passively mode-locked lasers, as essential tools for generating ultrashort pulses, have found widespread applications in industrial manufacturing, optical communications, biomedical imaging, and fundamental scientific research. Saturable absorbers serve as the key components governing the performance of such laser systems. Conventional saturable absorber materials, including semiconductor saturable absorber mirrors, carbon nanotubes, and graphene, however, suffer from inherent limitations in operational wavelength range, damage threshold, and environmental stability. In recent years, two-dimensional transition metal carbides and nitrides, known as MXenes, have emerged as a promising class of materials to address these challenges. Their unique metallic conductivity, broadband saturable absorption, ultrafast carrier dynamics, excellent thermal management capability, and versatile chemical tunability offer unprecedented opportunities for advanced saturable absorber applications. This review systematically summarizes the recent progress of MXene-based saturable absorbers, with an emphasis on their distinctive advantages in extending the mode-locked wavelength range, enhancing output pulse stability, and increasing the optical damage threshold. Furthermore, strategies for performance optimization through surface terminal group engineering, defect modulation, and heterostructure design are discussed in depth. Finally, the future prospects and key challenges toward industrial implementation of MXenes in ultrafast photonics are outlined, aiming to stimulate further advancements in high-performance ultrafast laser technology. Full article

This study applied density functional theory (DFT) to investigate gas-sensitive devices based on Pt- and Pd-doped SnS₂ monolayers, exploring their adsorption and sensing performance on four characteristic gases generated under normal operating or fault conditions of transformer oil. The adsorption behaviors and underlying sensing mechanisms of four gases on pristine and modified SnS₂ were systematically elucidated. The results reveal that Pt/Pd incorporation triggers a transition from weak physisorption to robust chemisorption. Compared to intrinsic SnS₂, the decorated monolayers exhibit dramatically augmented adsorption energies and accelerated interfacial charge transfer for all target molecules. Crucially, noble metal modification fundamentally modulates the electronic structure of the SnS₂ lattice, endowing the material with exceptional recognition specificity for distinguishing different gas species. These theoretical insights establish Pt- and Pd-SnS₂ as highly promising candidates for advanced DGA sensors, providing a robust materials design strategy for the condition monitoring of critical electrical infrastructure. Full article

Metals like Li, Sn, W, Nb and Ta accumulate mostly during the magmatic–hydrothermal transition and subsequent hydrothermal alteration of highly fractionated granites, especially greisenization. Evaluation of about 450 bulk-rock analyses, 1500 LA-ICP-MS analyses of quartz and 1600 EPMA and LA-ICP-MS analyses of mica from parental granites and related greisens and quartz–mica veins from four typical areas of European Variscan granite plutons with greisen mineralization (Beauvoir, France; Panasqueira, Portugal; and Cínovec and Nejdek, Erzgebirge, Czech Republic) illustrate diversity in initial magma composition (S- vs. A-types), in style of greisenization (pervasive greisenization in granite cupolas vs. vein-like greisen strings along joints), and in chemical evolution of quartz and micas during magmatic–hydrothermal transition. The contents of all monitored elements in quartz and mica from greisen and veins are of very high variability, with principal differences among studied localities. Generally, very low contents of Al (<100 ppm), Ti (<1 ppm) and Li (<10 ppm) or, on the contrary, extremely high contents of Al (>1000 ppm) or Li (>100 ppm) in quartz may indicate its hydrothermal origin. Contents of Sn, W, Nb, and Ta in micas tend to become depleted during greisenization, this trend is more pronounced in Nb and Ta than in Sn and W. Transition from magmatic to hydrothermal crystallization leads to an increase in the Ta/Nb values in mica: from 0.20 to 0.24 in S-type magmatic systems, and from 0.13 to 0.34 at Cínovec as a representative of A-type granites. Whether granite belongs to the S- or A-type is not essential for the development of greisenization. Full article

Zirconium (Zr) is a strategic metal resource whose performance is significantly degraded by high oxygen content. The external gettering process is an effective approach for in-depth deoxidation of Zr. In this study, the deoxidation behavior of Zr in the Ca-Y-CaCl₂ external gettering system was investigated by adjusting the chlorine potential through YCl₃ addition. The change of oxygen potential and its synergistic control mechanism during the variation of chlorine potential were systematically examined. The results demonstrated that with increasing chlorine potential, the system undergoes a sequence of reactions: chlorination of Ca, formation of metallic Y, formation of YOCl, dissolution of Y₂O₃, and formation of YCl₃, ultimately reaching a three-phase equilibrium of Y-YOCl-YCl₃. During this process, the oxygen content of Zr fluctuates notably, which is primarily attributed to the shift in the oxygen-transfer medium from Ca to Y. This transition changes the oxygen potential control mechanism from indirect Y-Ca control to direct Y control. After reaching equilibrium at 1173 K for 72 h, the equilibrium oxygen content of Zr initially remains stable with increasing chlorine potential, then gradually decreases, eventually reaching 20 ppmw. This trend is consistent with the mutual interaction of oxygen potential and chlorine potential. The findings provide important theoretical insights into the interaction between oxygen and chlorine potentials in deoxidation systems, elucidate the multi-element synergistic mechanism for oxygen control, and contribute to the design of efficient deoxidation systems. Full article

In this work, we describe a new dynamic rotational Thomson effect induced on rotating conductors exposed to a chopped laser beam which generalizes recently observed analog magneto-transverse Thomson effects. We assume the existence of an out-of-equilibrium self-induced Barnett magnetic field that depends on helical thermal fields propagating on rotating conductors, and is associated with thermoelectric vortices. We deduce, assuming the validity of the Faraday law on the rotating out-of-equilibrium conductors, a time-dependent rotational Thomson voltage, showing that it is detectable on rotating ferromagnetic samples. We then prove the existence of dynamic tunable local magnetic phase transitions on rotating conductors associated with time-dependent Curie temperature fluctuations proportional to the dynamic Thomson voltage. Finally, we outline the relevance of this new time-dependent magneto-transverse Thomson effect either for dynamic thermal management or for dynamic tunable local insulator–metal transitions on rotating nanodisks exploiting metamaterials. Full article

Fully integrated MITC4 (mixed interpolation of tensorial components) shells remain costly for large-deformation sheet-metal forming benchmarks at production mesh sizes. This paper presents a GPU-resident explicit MITC4 shell solver, implemented as a single CUDA pipeline in which co-rotational kinematics, assumed natural strain transverse shear, through-thickness J2 elasto-plasticity, and rigid-surface penalty contact remain in device memory. The study is positioned as computational verification and benchmarking for the Nakajima hemispherical-dome forming benchmark. Canonical shell tests verify the element kernel through membrane and bending patches and a force-driven cantilever, with the cantilever deflection agreeing with the MacNeal–Harder reference within about 2%. On the 10K-element Nakajima benchmark, the present solver agrees with Abaqus/Explicit with a mean von Mises error of 2.95% over 94% of specimen elements and a maximum shell thickness error of 2.08%. In the clamped/binder transition band, section-mean von Mises agrees to +1.0%, whereas section-maximum stress is under-predicted by 10.9%. A 50K-element Abaqus check remains bounded at 80 mm stroke, with section-mean von Mises differences of +0.6% globally and +0.4% in the transition band. For throughput, a separate 500K-element deck over 1.0 × 10⁻³ s and 15,808 steps give per-step speed-ups of 43.7×, 17.7×, and 13.5× versus 1-, 8-, and 32-core LS-DYNA MPP. Full article

In this work, we employed an easy hydrothermal method to prepare CuO and ZnO, as well as the prepared composite nanostructured electrodes of CuO@ZnO for supercapacitor applications. The systematic electrochemical performance evaluation of the prepared materials was conducted by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). CuO@ZnO nanocomposite reflected the best charge storing behavior with a specific capacitance of 513 F/g, followed by pristine CuO (190 F/g) and ZnO (416 F/g). The composite also demonstrated 25.67 Wh/kg and 400 W/kg for energy density and power density, respectively, suggesting improved electrochemical performance. Besides, the areal and volumetric capacitances were 0.77 F/cm² and 4.81 F/cm³, respectively, supported by the structural integrity and enhancement in electroactive materials utilization of the electrode material. Kinetic analysis showed that b values of the samples had mixed capacitive/diffusion-controlled charge storage, while higher diffusion coefficients and standard rate constants were apparent for ion transport or redox kinetics. EIS results showed a 2.14 Ω solution resistance, indicative of a decreased electrical resistivity. An asymmetric supercapacitor device fabricated by CuO@ZnO as the positive electrode and activated carbon (AC) as the negative electrode provided the specific capacitance of 48.57 F/g, energy density of 15.17 Wh/kg, and power density of 535 W/kg. After 10,000 cycles, the capacitance of the device was 76%, indicating good long-term stability. Full article

As a clean and renewable energy source, wind energy offers lower development and utilization costs than solar energy, making it the most promising renewable option. However, the carbon footprint of offshore wind power and its external impacts on cross-regional carbon emissions have not been investigated sufficiently. Using the provinces of Guangdong and Jiangsu as case studies, this study employs socioeconomic and environmental statistical data. It applies the environmentally extended multi-regional input–output (EE-MRIO) method to quantify cross-regional environmental spillover effects associated with offshore wind power development. The findings show that China’s power structure has been continuously optimized, with offshore winds achieving leapfrog growth since 2010. Through a “local consumption” model, offshore wind power in Guangdong and Jiangsu has effectively replaced coal-fired generation, substantially reducing carbon emissions locally and in neighboring areas. Jiangsu has reduced CO₂ emissions by 16.72 million tons annually, and Guangdong by about 7.23 million tons annually. Furthermore, offshore wind development drives the green transformation of upstream industries (e.g., steel, non-ferrous metals, and chemicals). It extends carbon-reduction benefits to resource-rich regions such as the Northwest and North China. As major manufacturing hubs, both provinces lowered the embodied carbon intensity of their export products by using clean electricity, thereby indirectly reducing the national carbon footprint through cross-regional trade. This study offers scientific insights to help policymakers optimize offshore wind layouts, facilitate coordinated regional emission reductions, and advance sustainable energy transitions. Full article

Pd-decorated Janus ZrSSe monolayers provide a promising platform for adsorption-coupled electronic modulation in two-dimensional materials. Using first-principles density functional theory, we systematically investigate the structural stability, electronic properties, and adsorbate-induced electronic response of Pd-modified Janus ZrSSe. The results show that Pd is most stably anchored at the hollow site on the S-terminated surface, with a formation energy of $-1.45$ eV, while substitutional incorporation remains energetically unfavorable even after HSE06 refinement. Compared with pristine ZrSSe, Pd decoration markedly strengthens the interaction with adsorbates, leading to strong chemisorption for CO ($-1.026$ eV) and C₂H₂ ($-0.748$ eV), whereas H₂ remains comparatively weakly bound ($-0.258$ eV). Electronic-structure analysis reveals that CO induces the most pronounced perturbation because of strong orbital hybridization between Pd 4d states and C/O 2p states, resulting in the largest band-edge modulation among the three adsorbates. More importantly, biaxial strain provides an effective external degree of freedom for continuously tuning the electronic structure: tensile strain widens the band gap, whereas compressive strain systematically narrows it and ultimately drives a semiconductor-to-metal transition at sufficiently large compression. These findings establish Pd-decorated Janus ZrSSe as a strain-tunable electronic material in which adsorption, orbital hybridization, and band-edge evolution are intimately coupled, offering fundamental insights into controllable electronic modulation in polar two-dimensional systems. Full article

To predict weld geometry and clarify structure–property relationships in high-speed coaxial dual-laser butt welding of 1 mm-thick SUS301 stainless steel sheets, an SSA-BP neural network model was established to describe the nonlinear correlation between welding parameters and weld morphology. The model related continuous laser power, welding speed, pulse frequency, and pulse width to weld width and penetration depth. To improve the transparency of model validation, conventional BP and SSA-BP models were compared using the same independent test set, and five-fold cross-validation was performed using the original experimental samples. On the independent test set, the SSA-BP model achieved an overall correlation coefficient of R = 0.960, with RMSE values of 0.0561 mm and 0.0439 mm for weld width and penetration depth, respectively. Compared with the conventional BP model, SSA-BP reduced the overall RMSE, MAE, and MAPE by 25.9%, 36.4%, and 29.6%, respectively. The five-fold cross-validation further indicated stable prediction performance under different data partitions. Based on the predicted and experimentally measured weld geometry, candidate parameter sets were screened according to the weld aspect ratio (Φ = h/w). Within the present experimental window, joints with Φ = 0.82–0.84 showed more stable weld formation and relatively higher ultimate tensile strength (1211.4–1264.8 MPa) than two representative joints outside this interval (796.0 MPa at Φ = 0.63 and 1061.1 MPa at Φ = 0.88). Therefore, this interval should be regarded as a favorable empirical range under the present welding conditions rather than a universal optimum. Fractographic observations of a representative high-strength joint showed abundant dimples and tear ridges, indicating ductile fracture characteristics. EBSD analysis further revealed a graded microstructure from the weld center to the base metal. The weld center and fusion line-adjacent regions exhibited relatively high fractions of high-angle grain boundaries (66.2–70.6%), while phase distribution, GND density, and KAM maps indicated a gradual phase transition and localized but non-continuous strain concentration features across the joint. These results indicate that the present approach provides an effective route for weld geometry prediction and for linking morphology screening with tensile response and microstructural heterogeneity in SUS301 thin sheet welding. Full article