Search Results (569)

Fracturing is the dominant stimulation technique for low-porosity, low-permeability dolomite gas reservoirs, yet the lack of systematic laboratory research on multistage alternating acid etching mechanisms restricts field construction parameter optimization. Targeting the low-permeability Xixiangchi Formation dolomite reservoir in the eastern Sichuan Basin, this work develops a high-temperature, high-pressure core acid etching system coupled with 3D surface scanning. A reliable lab-to-field parameter conversion is established based on the Reynolds and Froude similarity criteria. Four-factor three-level orthogonal tests are conducted to quantify the impacts of pad fluid-to-acid viscosity ratio, total acid volume, pumping rate, and alternating injection stages on JRC-characterized wall roughness and fracture conductivity. The results show an identical factor dominance ranking for both indicators: viscosity ratio > pumping rate > injection stages > total acid volume. The optimal stimulation scheme is determined as a 50:1 viscosity ratio, 120 mL total acid volume, 12.54 mL/min laboratory pumping rate (equivalent to 8 m³/min in field operations), and 3 alternating injection stages. An elevated viscosity ratio intensifies viscous fingering, induces heterogeneous dolomite dissolution, and forms abundant irregular asperities on fracture surfaces. These self-supporting rough structures sustain stable seepage channels and markedly improve conductivity, verifying the positive roughness-conductivity correlation and revealing the core mechanism of heterogeneous etching-driven conductivity enhancement. The findings provide direct experimental support and parameter guidance for multistage alternating acid fracturing design in the Xixiangchi Formation and analogous tight dolomite reservoirs. Full article

Quartz wafer dicing technologies primarily rely on mechanical cutting and etching processes. Mechanical cutting is easy to generate the micro-cracks along the wafer edges, which compromises component precision. Furthermore, etching processes are associated with long processing times, high manufacturing costs, and environmental concerns. To address these limitations, this study proposes an electrochemical discharge cutting machining (ECDCM) method using a micro-tungsten carbide helical electrode performing orbital circular cutting (OCC) to evaluate the feasibility and optimization of quartz wafer dicing. Experimental studies were conducted to evaluate the effects of applied voltage, pulse duration, Z-axis feed rate, and duty factor on slot width, slot depth, slot surface quality and tool electrode wear. The results demonstrate that employing an OCC of micro-electrode facilitates the efficient flow of electrolyte into the machining zone, thereby enhancing discharge stability and slot quality. Compared to circular path cutting (CPC) with a rotating electrode, the proposed method reduces machining time by nearly four times and decreases material loss during circular quartz wafer cutting by approximately 50%. These findings indicate that the proposed machining approach provides high efficiency and high-quality quartz wafer cutting. Full article

Developing efficient and stable oxygen evolution reaction (OER) electrocatalysts is crucial to the practical application of water electrolysis for hydrogen production. Herein, a tubular array of a mesoporous NiMoO₄@NiFeS heterostructure was anchored on nickel foam through successive hydrothermal processing, liquid etching and direct sulfur vulcanization. The efficient charge transfer, phase transition and full exposure of active sites at the heterostructure’s interfaces, as well as its superhydrophilic surface, endow NiMoO₄@NiFeS with exceptional OER activity. A series of electrochemical experiments indicate that in 1.0 mol·L⁻¹ KOH, NiMoO₄@NiFeS delivers overpotentials as low as 180 and 223 mV at current densities of 10 and 100 mA cm⁻², respectively, and that a Tafel slope of merely 25.9 mV dec⁻¹ is achieved on NiMoO₄@NiFeS, evidencing that the tubular array of the mesoporous NiMoO₄@NiFeS heterostructure significantly facilitates the interfacial transfer of charge/mass and the decrease in the energy barrier of the rate-determining step. This work provides valuable insights for the construction of an efficient and low-cost electrocatalyst with hierarchical mesoporous core–shell structures. Full article

Hydrophobic and superhydrophobic surfaces have emerged as key solutions for fluid transport, biofouling prevention, and energy efficiency, with market forecasts projecting a compound annual growth rate (CAGR) of over 15% through 2030 due to their broad range of applications. This review critically examines the principles of natural hydrophobicity, as exemplified by lotus leaves and shark skin, and their translation into engineered surfaces via micro/nanofabrication techniques, such as laser patterning, etching, and self-assembly. Recent advances in hybrid nanomaterials have demonstrated WCAs in the range of 140–160°, along with enhanced mechanical strength and chemical stability, enabling applications in self-cleaning, anti-corrosion, and oil–water separation technologies. Superhydrophobic coatings are particularly important for reducing ice adhesion by more than 80%, while drag reduction in pipelines can reach up to 30%, contributing to energy savings. Despite these advances, challenges remain in achieving long-term stability under harsh environmental conditions, minimizing environmental impact, and developing cost-effective, scalable fabrication techniques. Future directions focus on environmentally friendly, multifunctional nanocomposites with switchable wettability, including pH- and light-responsive coatings capable of reversibly transitioning between superhydrophilic (<5°) and superhydrophobic (>150°) states, paving the way for sustainable and adaptable surface technologies. Full article

To develop eco-friendly and highly efficient fruit and vegetable preservation materials, this study uses the multi-gradient micro–nano roughness structure and bioactive properties of orange peel as a biomimetic model, aiming to construct a functional film with a unique dual mechanism of physical barrier protection and active preservation. Using soft etching and secondary transfer methods, with polydimethylsiloxane as an intermediate template, and through a repeated freeze–thaw cross-linking process, a polyvinyl alcohol system containing orange peel essential oil was cast to successfully prepare a biomimetic film featuring the micro–nano hierarchical structures found on the surface of orange peel. The study indicates that the biomimetic film accurately replicates the cross-scale hierarchical structures of the natural orange peel surface. Structure–property relationship analysis revealed that the biomimetic film containing 15% orange peel essential oil exhibited the optimal comprehensive performance, characterized by significantly enhanced tensile strength and improved water vapor barrier properties, while demonstrating effective antioxidant and regulated antibacterial activities. Crucially, compared to conventional flat active films, the replicated multi-scale surface roughness provides clear functional advantages by physically optimizing interface properties and cooperating synergistically with the chemical vapor release of the essential oil. Blueberry preservation experiments confirmed that the biomimetic film successfully maintains fruit firmness, vitamin C, and anthocyanin content, while suppressing weight loss and decay rates. This study simulates the microenvironmental control mechanisms of orange peel, highlighting the scientific novelty of structural–chemical synergistic design for advanced functional packaging. Full article

Optimizing industrial wastewater treatment systems requires efficient, cost-effective, and easily adaptable technologies. In this context, adsorption emerges as a promising alternative through the use of advanced nanostructured materials that optimize contaminant removal and facilitate their separation from the treated medium. This work evaluates the use of nanoporous anodic aluminum oxide (AAO) as a nanoadsorbent for the removal of Eriochrome Black T (EBT) dye, analyzing the effect of thermal and chemical modifications on its performance. The results demonstrated that calcination and chemical etching with NaOH, applied individually, increased removal efficiency by 10% compared to untreated AAO. Notably, the combined treatment (calcination + alkaline etching) boosted removal efficiency by 38% after 1 h of contact. Furthermore, this synergistic modification extended the viability of the process to alkaline media (up to pH 10) and allowed the material to be reused for four consecutive cycles, maintaining an 85% removal rate. Finally, the kinetic analysis elucidated the influence of the structural and chemical modifications on the adsorption rate, obtaining satisfactory correlations with various theoretical models. Full article

Silicon anodes hold great promise in high-energy lithium-ion batteries (LIBs) owing to their ultrahigh theoretical specific capacity, appropriate operating voltage, and low costs. However, the drastic volume expansion, inferior electronic conductivity, and unstable solid electrolyte interphase of Si anodes severely restrict their practical application. Herein, a nest-shaped microporous silicon (NMPSi) is rationally designed via acid–base co-etching and then synergistically regulated by surface thin-film carbon coating and ZIF-67-derived hard carbon nanotemplate (NMPSi@THC) by an in situ liquid-phase coating strategy. The constructed unique architecture is capable of buffering the huge volume expansion of inner NMPSi during cycling and constructing an optimized electron/ion transport network, thereby stabilizing the SEI film and preserving the electrode’s structural integrity. When it is evaluated as a LIB anode, the NMPSi@THC exhibits typically improved initial coulombic efficiency (ICE) and outstanding long-life cyclic stability (622.7 mAh g⁻¹ after 300 cycles at 1 A g⁻¹ and 2 mg cm⁻²). Furthermore, the NMPSi@THC//LiFePO₄ full cell delivers an ultrahigh ICE of 94% and a capacity retention rate of 86%, demonstrating its practical application potential. Compared with most recently reported Si anodes, this report delivers better cycling stability and maintains more intact electrode structure under relatively high current density and areal mass loading in half/full cells after long-term cycling. This research offers a convenient and scalable route to fabricate highly stable microporous Si anodes toward high-energy and long-lifespan LIBs. Full article

This study investigates the processing temperature characteristics and etching behavior of fused silica using an atmospheric pressure microwave plasma jet. The temperature distribution within the processing region was measured in real time via infrared thermography. The effects of microwave input power, argon flow rate, and CF₄ flow rate on the processing temperature were systematically examined using a single-factor approach. Experimental results reveal a strong positive correlation between the plasma temperature and microwave power. The temperature initially rises and then declines with increasing argon flow, peaking at 3 slm, while it increases and eventually stabilizes with higher CF₄ flow. Fixed-point etching demonstrates that the etching rate increases with rising processing temperature. Furthermore, heat accumulation during prolonged dwell time leads to a nonlinear increase in the removal rate. This effect can be effectively mitigated by employing a multi-segment processing strategy, enabling more stable and controllable material removal. The effectiveness of this processing method has also been verified on a fused quartz sub-mirror. Full article

The demineralization of tooth enamel is the primary consequence of dental caries, leading to cavities and finally tooth loss. Erosive tooth wear from acidic beverages and food is another factor that degrades enamel. In both cases, an acidic environment leads to etching and the final dissolution of tooth mineral, i.e., hydroxyapatite. Here, this process is discussed from a chemical perspective, taking into account the solubility of calcium phosphate and the presence of the pellicle (protein layer) and plaque (bacterial biofilms), which both affect the dissolution rate. While low pH is definitely decisive, calcium-binding ligands (e.g., acid anions, proteins) contribute to dissolution by removing calcium ions from the equilibrium. This is an important effect in the oral cavity where the concentration of biomolecules is high. The situation is complicated by the fact that the composition of saliva and the oral microbiome vary considerably between individuals. The state of current knowledge on the demineralization of enamel is summarized and discussed, also in the context of approaches to prevent dental caries and erosive tooth wear. Full article

The rapid expansion of solar photovoltaic (PV) deployment has led to increasing concerns regarding end-of-life module management and the sustainability of material supply chains, where waste volumes are projected to reach 3.3–5.6 million tons by 2045. This study evaluates the environmental and economic impact of advanced photovoltaic recycling in Germany, focusing on high-value material recovery from crystalline silicon modules. A Full Recovery of End-of-Life Photovoltaics (FRELP) pathway is developed, integrating light-pulse delamination and molten salt etching, and a comparative life cycle assessment and economic assessment framework is applied. The results indicate that advanced recycling achieves high recovery rates for silicon, silver, aluminum, copper and low-iron glass, yielding around €1174.88 per ton of panels recycled. Economic analysis shows that manufacturing PV modules from recycled materials reduces costs by approximately 60–77% compared to virgin material production, mainly due to avoided energy-intensive upstream processes. From an environmental perspective, the recycling-based pathway yields net benefits across impact categories, as avoided impacts from primary material extraction outweigh additional burdens associated with recycling. Overall, PV recycling in Europe is shown to be environmentally and economically favorable; however, technological maturity and policy constraints remain key barriers to large-scale implementation and a holistic overall recycling process, indicating the need for targeted policy support. Full article

In logic device development, gate-all-around nanosheet field-effect transistors (GAA NSFETs) are widely regarded as the future mainstream architecture. Due to an innovative stacked-channel design, a novel process module of channel release has been introduced, posing significant challenges to device manufacturing. The channel release quality plays a decisive role in the device’s turn-on voltage and operating speed. Meanwhile, the complex interferences are undoubtedly brought by diverse structures and manufacturing thermal budgets of GAA NSFETs. Here, the non-plasma gas etching, which is not yet widely used in the current industry, is adopted for channel release. The influences of nanosheet width, spacing, and annealing conditions on the etching process are systematically studied. A SiGe/Si etching selectivity as high as 87 is achieved. With increasing channel width, a downward trend in the single-sided damage in the central region of Si nanosheets is shown. At >100% over-etching, the Si single-sided damage in structures with different channel spacing is controlled below 1 nm. The intensified diffusion of Ge elements in the SiGe layer and a gradual slowdown of the SiGe etching rate are caused by increasing the annealing temperature. The root mean square (RMS) value of the channel surface roughness is reduced from 0.087 to 0.069 nm by adding the *H radical pretreatment into the process. These findings provide valuable guidance for developing a channel release etching process with high selectivity, low damage, a stable process window, and low fabrication difficulty. Full article

To address wellbore instability and the technical challenges associated with high-density water-based drilling fluid loss control in deep shale gas formations of the Sichuan-Chongqing region in China, a novel nano-micro sealant designated CLG-Seal was synthesized via molecular structural optimization. The molecular structure of newly developed CLG-Seal exhibits distinct core–shell structural characteristics. The inorganic nano-silica constitutes the rigid core of CLG-Seal, which guarantees its plugging performance. The hydrophobically associating polymer which is coated on the surface of nano-silica constructs the flexible shell of CLG-Seal, endowing the CLG-Seal with excellent gel-forming capacity, adhesion film-forming capacity, deformability and perfect dispersibility. Transmission electron microscopy and scanning electron microscopy were employed to characterize the morphology of the CLG-Seal nanomicron-scale plugging agent. The sealing performance and underlying mechanisms of CLG-Seal were subsequently evaluated via particle plugging apparatus tests, displacement experiments, and etched glass micromodel simulations. Field trials conducted in the third section of Well WY3-2-3HF validated the application effectiveness of this agent in drilling fluid systems. The results indicate that the nano-micro sealant CLG-Seal exhibits a median particle size of D₅₀ is 146 nm, which can be modulated by adjusting the synthesis conditions. The nano-micro sealant CLG-Seal significantly mitigates fluid loss in low-permeability microfractures and fissures. Notably, a concentration of merely 3% is sufficient to achieve optimal nano-micro plugging performance. The results of the mechanism study indicate that while the CLG-Seal particles are close to each other, the polymer chains with flexible long chain structure which are coated on the surface of nano-silica constructs tend to be intertwined, forming a cross-linked network structure of gel film, thereby increasing the interaction between nano-micron particles and forming an impermeable plugging film. In addition, due to the nanoscale effect, the CLG-Seal has a strong tendency to adsorb onto the surface of shale rock through hydrogen bonding with the shale matrix. The hydrophobically associating polymer with high elastic modulus and excellent mechanical properties can enhance the pressure-bearing capacity of the filter cake through elastic deformation. Therefore, these nano-micron particles can form a strong sealing film on the filter cake and at the micropores of shale rock, thereby creating a dense mud cake on the outside of the shale formation. Field trial results demonstrate that the incorporation of the nano-micro sealant CLG-Seal into the drilling fluid for the third section of Well WY3-2-3HF reduced the PPA fluid loss to 4.6 mL. This value represents a substantial reduction compared to adjacent wells and signifies a remarkable improvement over the drilling fluids previously employed in the Longmaxi Formation of this block. Furthermore, the treated drilling fluid exhibited a superior filtration control pressure capacity of 10.5 MPa. The operation was completed successfully without any lost circulation or wellbore instability, and achieved a drilling footage of 42 h with an average penetration rate of 7.81 m/h. The mud weight was reduced by approximately 0.08–0.10 g/cm³ compared to offset wells. These results confirm the excellent application efficiency of the newly developed CLG-Seal in field operations. Full article

To overcome the challenges of processing soft-brittle potassium dihydrogen phosphate (KDP) crystals, this study proposes a back-propagation (BP) neural network model for the rapid prediction of the ion beam removal function using Faraday cup scanning data (a method that measures the spatial distribution of ion beam current density). By correlating current density measurements with point etching experiment results, the model accurately maps both the linear relationship (R² = 0.98) between peak removal rate and peak current density, and the non-linear relationship between the full width at half maximum (FWHM) of the beam and the removal function. The predicted removal function demonstrates high accuracy, with a volume removal rate error of just 2.56% compared to experimental results. Furthermore, this method drastically reduces calculation time from approximately 2 h (required by the conventional point-etching experiment, which involves iterative vacuum cycling, etching, and ex situ interferometry) to just 2 min, significantly improving efficiency. Applied to the ion beam polishing of a 50 mm × 50 mm × 10 mm KDP crystal, the model proved highly effective. The surface figure error was corrected from an initial 0.298λ peak-to-valley (PV) and 0.0496λ root-mean-square (RMS) to 0.167λ PV and 0.036λ RMS, where λ (632.8 nm) is the wavelength of the He-Ne laser used for interferometric surface measurement, achieving a convergence ratio (defined as the ratio of initial PV to final PV) of 1.78. This research provides a high-efficiency, high-precision technical solution for manufacturing KDP components for inertial confinement fusion (ICF) applications. Full article

With the growing global demand for sustainable resources, recycling spent lithium-ion batteries has become a strategic priority. Conventional pyrometallurgical and hydrometallurgical methods suffer from high energy consumption, severe pollution, and structural destruction, making them unsuitable for regenerating high-nickel cathodes. In this work, spent polycrystalline high-nickel LiNi_0.9Mn_0.1O₂ cathodes were selected, and an upcycling strategy integrating acid etching, hydrothermal relithiation, short-time annealing, and simultaneous Li₄Ti₅O₁₂ (LTO) coating was developed. This process directly transformed degraded polycrystalline cathodes into single-crystal cathode materials with excellent structural stability and electrochemical performance. During regeneration, lithium compensation and lattice recrystallization effectively repaired lithium loss, reduced Li/Ni cation mixing, reactivated the degraded structure, and reconstructed a highly ordered layered single-crystal framework. The LTO coating further stabilized the cathode/electrolyte interface, suppressed side reactions, alleviated volume strain, and promoted Li⁺ transport kinetics. Electrochemical measurements showed that the regenerated single-crystal cathode exhibited superior structural integrity, strong resistance to crack propagation, low polarization, excellent rate capability, and long-term cycling stability. A capacity retention of 84.3% was achieved after 300 cycles at 1C, outperforming commercial polycrystalline cathodes. This strategy provides an efficient and promising route for the direct regeneration of spent high-nickel ternary cathodes. Full article

In the semiconductor industry, fluorinated gases with high global warming potential (GWP) are recognized as significant sources of greenhouse gas emissions. This study presents a measurement-based analysis of a 300 mm wafer etching process using CF4, C4F6, and C4F8 gases. The use rate of gas (Ui), unreacted fraction (1-Ui), and by-product generation rate (Bi) were evaluated under varying plasma intensity conditions. The results show that the unreacted fraction (1-Ui) decreased with increasing plasma intensity for all process gases, indicating enhanced gas dissociation efficiency. In contrast, the by-product generation rate (Bi) exhibited non-linear behavior due to the complex interplay of dissociation and recombination reactions within the plasma. Furthermore, the measured Ui and Bi values showed significant deviations from the default emission factors provided in the 2006 IPCC Guidelines and the 2019 Refinement. Variability analysis based on the coefficient of variation (CV) was conducted using measurements obtained under different plasma conditions (n = 3). The results indicate that Ui exhibited relatively stable behavior with low variability (CV < 0.3), whereas Bi showed higher variability depending on the type of by-product gas, reflecting stronger sensitivity to process conditions. These findings highlight that IPCC default emission factors may not adequately reflect actual process conditions and underscore the importance of incorporating measurement-based, condition-dependent variability into emission estimation. Full article