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High-purity graphite is of significant interest because of its diverse range of industrial applications. The traditional HF purification method produces a large amount of fluorine-containing wastewater, harming the environment. The environmentally friendly alkali-acid purification method avoids the generation of fluorinated wastewater. Herein, natural flake graphite sourced from Linkou County, Heilongjiang Province, is utilized as the primary material to address the challenge of low purity encountered in conventional alkali-acid purification methods. In addition, the response surface method is used to optimize the temperature, mass concentration and liquid-to-solid ratio of the hydrothermal alkali dissolution step in the purification process. To enhance the purification process, an integrated alkaline-acid approach is proposed, including a pretreatment step, the incorporation of co-solvents and the implementation of multiple acid-leaching stages. The x-ray diffraction (XRD), scanning electron microscopy (SEM) and x-ray fluorescence spectroscopy (XRF) measurements were used to characterize the purification effect. Experimental results show that through combined pretreatment, alkali dissolution and acid leaching, the fixed carbon content of graphite can be increased from 94% to 99.96%. The alkali-acid purification method greatly improves the purity of graphite and provides good potential for graphite in various industrial applications.

The purpose of this work is to analyze the development direction and prospects in the field of artificial intelligence (AI) in metal–organic frameworks (MOFs) and to provide reference information for related research and industry personnel. The scientific papers on AI in MOFs published in Web of Science database from 2013 to mid-2024 were collected. Bibliometric methods and knowledge mapping visualization software were used to analyze the papers. Both quantitative statistics and qualitative comparative analysis of global scientific papers were done in terms of annual paper trends, papers by major countries, authors, institutions, journals and research topics, respectively. The results showed that the number of published papers has increased in recent years. The top three productive countries are China, the USA and Germany, respectively. The top three productive institutions are Guangzhou University, Northwestern University and Chinese Academy of Sciences, respectively. Reference co-citation analysis classifies references into four clusters, and keyword co-occurrence analysis divides keywords into six clusters. Bibliometric and network analyses were utilized to examine the distribution of research outcomes, enabling scholars to discern the prevailing trends and focal points within the domain of AI-MOFs.

The solidification microstructures of plain and inoculated 6061 aluminum builds manufactured with gas metal arc-directed energy deposition were studied with a combination of models and experiments. Electron back-scatter diffraction (EBSD) showed that the plain 6061 build had large, columnar grains with intergranular solidification cracking, while the inoculated build had a near-equiaxed, fine grain microstructure with no solidification cracks. By combining EBSD and energy dispersive spectrometry, the inoculated build has been shown to have exhibited globular growth while the non-inoculated build displayed a dendritic microstructure. A combination of heat transfer and modified grain morphology models were employed to predict the solidification morphology of the 6061 builds, which closely matched experimental results. A modification is proposed to the criterion marking the transition from globular to dendritic growth that better matches experimental results in this work. The results of this study are expected to provide improved methods to predict solidification microstructure for the development of new materials and processing parameters for additive manufacturing.

To achieve rapid freezing of the coal body in the step during rock cross-cut coal removal by freezing method, coal thermal conductivity with different water capacities at varying freezing temperatures is experimentally tested, and the hyperbolic model of thermal conductivity is proposed. The model parameters are optimized using the artificial neural network (ANN) method, and the model can mimic the change rule about thermal conductivity with temperature during the freezing process. Meanwhile, the time-varying law during the freezing process of the coal body is numerically analyzed using the thermal conductivity hyperbolic model and heat conduction theory; simulation results are analyzed and compared with measured results. After optimizing three parameters of the thermal conductivity hyperbolic model with the ANN approach, the calculated thermal conductivity values are distributed on a 1:1 line with measured results. This indicates that combining heat conduction theory with the thermal conductivity hyperbolic model can accurately predict the time-varying characteristics of temperature during the freezing process of the coal body with moisture content. Moreover, when coal body water capacity is about 12%, and its temperature decreases the fastest during freezing process This method establishes a theoretical foundation for forecasting the temperature aging properties of rapid freezing during the rock cross-cut coal removal process.

Poly(vinylidene fluoride)/MgO copolymer nanofiber composites have been successfully synthesized with MgO nanoparticles (MgO NPs) variations using the electrospinning method as a promising strategy to obtain nanofiber models. The quantitative analysis of the FTIR spectrum using the Kramers–Kronig (K–K) relationship shows that the change of (Delta left(text{LO}-text{TO}right)) from (139 → 114) cm⁻¹ indicates the change of strain, crystal symmetry, and phase transition. The crystallinity index increased (26.9 → 31)% caused by the increased concentration of MgO NPs in the composites rose as the result of XRD spectra analysis. The SEM analysis has provided valuable insights into the morphology of cPVDF nanofibers, demonstrating their predominantly linear structure while the influence of MgO concentration on nanofiber diameter decreased (621 → 347) nm. Based on the results, an increase in MgO concentration, a higher vibrational range of optical phonons, and an increase in crystallinity index successfully produced a copolymer material structure dominated by a linear nanofiber structure.

Metals extraction and processing generate a substantial amount of industrial waste, posing significant environmental hazards. To reduce the accumulation of such waste, this paper incorporates steel slag (SS) into a lime (CH)–sodium sulfate (SN) composite-activated cementitious system. The mechanical properties, hydration products, and microstructure of the cementitious system with varying SS contents were characterized. The results indicate that the addition of SS not only enhances the mechanical properties of the cementitious system but also significantly reduces its cost and energy consumption. When the content of SS is lower than 30%, it does not reduce the generation of C-(A)-S-H and ettringite in the cementitious system, and can be used as a micro-filling to make the matrix dense, thus improving the mechanical properties of the cementitious system. However, as the SS content continues to increase, the formation of C-(A)-S-H and ettringite in the cementitious system decreases, leading to an increase in the number of harmful pores in the matrix and a subsequent reduction in the mechanical properties of the system. This study provides important insights into the sustainable development of metal extraction and processing.

Nanocellulose extracted from agro-waste rice straw has been utilized to fabricate carbon nanofiber films. The nanocellulose-based films were drop-casted and underwent a two-step thermal treatment: stabilization at 180°C in air and carbonization at 700°C in a nitrogen atmosphere. Phosphoric acid (PA) was incorporated into the nanocellulose solution, resulting in a 17% reduction in stabilization activation energy and a 20% increase in carbonization yield. Additionally, PA facilitated phosphorus doping, leading to a phosphorus concentration of up to 5%, and enhanced the Brunauer–Emmett–Teller (BET) surface area from 223 m² g⁻¹ to 334 m² g⁻¹. Structural analysis via XRD, Raman spectroscopy, and TEM confirmed the formation of a turbostratic graphitic structure in the PA-doped carbon nanofiber films. This increased surface area and graphitic structure make the films highly promising for diverse applications, including flame-retardant coatings, sensors, energy storage devices, and biomedical uses.

Material test reactors (MTRs) are used to irradiate nuclear fuels and materials to develop data for how they endure neutron bombardment in or near reactor cores. Most historic MTRs, and all that remain operational in the US today, are water-cooled types and produce a thermalized neutron flux. New irradiation facilities are needed which can produce neutron energy spectra relevant to fast and fusion reactor environments. Construction of these facilities will take several years of steadfast funding to complete, which poses a formidable schedule challenge for current fast and fusion reactor developers. Irradiation designs which modify the neutron energy spectra delivered to test specimens in thermal spectrum MTRs, an approach referred to as “spectral tailoring”, can be used to approximate several relevant phenomena in the materials needed to enable fast and fusion reactor technologies. This approach is imperfect, but still valuable in the present situation. The two highest flux MTRs operational in the United States, the Advanced Test Reactor (ATR) and High Flux Isotope Reactor (HFIR), have rich histories, ongoing developments, and new potentials for spectral tailoring that will be reviewed and discussed in this paper.

Laser powder bed fusion (LPBF)-based additive manufacturing (AM) provides high print resolution which enables design freedom and the fabrication of complex geometries. However, anisotropy is a major challenge that impacts the properties of LPBF materials. In this study, we investigate the mechanical anisotropy of an LPBF-produced BCC Ti-45Nb alloy that exhibits a weakly elongated (near equiaxed) microstructure with no preferred grain orientation. Based on uniaxial tensile tests, profilometry-based indentation plastometry, and microhardness tests along the laser scan and build directions, we find a strong mechanical anisotropy in the randomly oriented LPBF Ti-45Nb alloy. By employing these distinct multi-scale mechanical testing techniques, we delineate the influence of LPBF microstructural features such as grain morphology, cellular structures, melt pool boundaries, and crystallographic texture on the anisotropic behavior. Our work specifically highlights the role of melt interface length on the mechanical (yield) anisotropy.