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Depending on the requirements of specific applications, implanted materials including metals, ceramics, and polymers have been used in various disciplines of medicine. Titanium and its alloys as implant materials play a critical role in the orthopedic and dental procedures. However, they still require the utilization of surface modification technologies to not only achieve the robust osteointegration but also to increase the antibacterial properties, which can avoid the implant-related infections. This article aims to provide a summary of the latest advances in surface modification techniques, of titanium and its alloys, specifically in biomedical applications. These surface techniques include plasma spray, physical vapor deposition, sol-gel, micro-arc oxidation, etc. Moreover, the microstructure evolution is comprehensively discussed, which is followed by enhanced mechanical properties, osseointegration, antibacterial properties, and clinical outcomes. Future researches should focus on the combination of multiple methods or improving the structure and composition of the composite coating to further enhance the coating performance.

Under the “dual-carbon” goals background, the Chinese iron and steel industry urgently needs to undergo a low-carbon transformation. Currently, promoting the substitution of coke oven gas (COG) for natural gas to develop shaft furnaces is a crucial initiative for implementing sustainable development. Through thermodynamic calculations, the iron yield and CO 2 emissions of the direct reduction process in the shaft furnace were systematically analyzed. A thermodynamic calculation based on mass balance and heat balance was established to clarify the effects of key parameters [total iron content (TFe) of iron ore, metallization degree (MD), and generation temperature of metallic Fe (T MFe )] on the process performance. The thermodynamic calculation results show that, (1) Heat balance dominates the total carbon consumption. (2) Enhancing TFe is one of the most effective strategies to improve the yield of metallic Fe (Y MFe ) and reduce CO 2 emissions. Taking 100 mol of COG as the calculation basis, under the conditions of MD = 98% and T MFe  = 900 °C, increasing TFe from 45 to 70%, raises Y MFe from 1.38 to 2.24 kg, while CO 2 emissions per ton of metallic Fe (t-MFe) decrease from 1200.04 to 740.08 kg. Furthermore, MD and T MFe exert significant regulatory effects on both Y MFe and CO 2 emissions. (3) Under the conditions of TFe = 66%, T MFe  = 900 °C, and MD = 94%, the consumption of COG for direct reduction is 838.38 m 3 /t-DRI. For a coke oven with a production capacity of 1.2 million tons, with gas production of 53,736 × 10 4 m 3 /a, the generated COG can support the shaft furnace to achieve an annual Y MFe of 48.77 × 10 4 t and CO 2 emissions of 41.64 × 10 4 t. When the top gas is recycled as fuel of the heating furnace, the heat consumption of the heating furnace can be supplemented by no more than 20% of the top gas. The remaining 80% of the top gas can be recycled after the CO 2 capture, which can significantly reduce the production costs, carbon consumption, and CO 2 emissions. The present work may provide the theoretical guidance for choosing optimal parameters of shaft furnace process in China.

Titanium-extracted tailing is a by-product generated during titanium-bearing blast furnace slag treatment process. The crystallization behavior of the titanium-extracted tailing during the cooling process is significant to its utilization for glass ceramics preparation. In this work, the CaO-SiO2-Al2O3-MgO-TiO2-FeO slag was used to explore the effect of CaO/SiO2 ratios on titanium-extracted tailing crystallization. FactSage 8.2 calculation and mineralogical characterizations were conducted to investigate the phase and microstructure evolution during the slag cooling process. Single hot thermocouple technique (SHTT) was employed for in situ observation of the crystallization process of the slag during the cooling process. The obtained results indicated that the perovskite, melilite, spinel, diopside and anorthite phases would be crystallized during the cooling process when the CaO/SiO2 ratios of the slag were 0.7–1.1. Increasing the CaO/SiO2 ratio to 1.3 and 1.5 promoted the crystallization of olivine and merwinite phases, however, inhibited the crystallization of diopside and anorthite phases. The initial crystallization temperature and the liquid phase disappeared temperature of the slag enhanced with improving CaO/SiO2 ratios. The initial crystallization temperature was controlled by perovskite phase precipitation when the CaO/SiO2 ratios of slag reached 0.7–1.3. Whereas the initial crystallization temperature was controlled by the crystallization of spinel phase when the CaO/SiO2 ratio of slag was 1.5. The incubation time for crystal nucleation reduced with increasing CaO/SiO2 ratios that promoted slag crystallization. Moreover, increasing the CaO/SiO2 ratio from 0.7 to 1.5 enhanced the critical cooling rate from 4 °C s−1 to 11 °C s−1.

With the continuous progress and development in the biomedicine field, metallic biomedical materials have attracted the considerable attention of researchers, but the related procedures need to be further developed. Since the traditional metal implant materials are not highly compatible with the human body, the modern materials with excellent mechanical properties and proper biocompatibility should be developed urgently in order to solve any adverse reactions caused by the long-term implantations. The advent of the high-entropy alloy (HEA) as an innovative and advanced idea emerged to develop the medical implant materials through the specific HEA designs. The properties of these HEA materials can be predicted and regulated. In this paper, the progression and application of titanium-based HEAs, as well as their preparation and biological evaluation methods, are comprehensively reviewed. Additionally, the prospects for the development and use of these alloys in implant applications are put forward.

The microcrack initiation and evolution behavior of Fe-C alloy under uniaxial tensile loading are investigated using molecular dynamics (MD) simulations. The model is stretched along the z-axis at a strain rate of 2 × 109 s−1 and temperatures ranging from 300 to 1100 K, aiming to elucidate the microscopic deformation mechanisms during crack evolution under varying thermal conditions. The results indicate that the yield strength of Fe-C alloy decreases with a rising temperature, accompanied by a 25.2% reduction in peak stress. Within the temperature range of 300–700 K, stress–strain curves exhibit a dual-peak trend: the first peak arises from stress-induced transformations in the internal crystal structure, while the second peak corresponds to void nucleation and growth. At 900–1100 K, stress curves display a single-peak pattern, followed by rapid stress decline due to accelerated void coalescence. Structural evolution analysis reveals sequential phase transitions: initial BCC-to-FCC and -HCP transformations occur during deformation, followed by reversion to BCC and unidentified structures post-crack formation. Elevated temperatures enhance atomic mobility, increasing the proportion of disordered/unknown structures and accelerating material failure. Higher temperatures promote faster potential energy equilibration, primarily through accelerated void growth, which drives rapid energy dissipation.

This study aimed to elucidate the dynamic changes in meat quality attributes and metabolomic profiles of Dezhou donkey longissimus lumborum (LL) during extended chilled storage. Donkey longissimus lumborum (LL) muscles (n = 4) were vacuum-packaged 24 h post mortem and stored at 0–4 °C for 0, 7, 14, or 21 days, followed by a 5-day aerobic display. Meat quality parameters and microstructural characteristics were evaluated, and untargeted metabolomics was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Extended storage significantly improved tenderness (shear force decreased from 76.40 to 27.84 N; p < 0.05), concurrent with progressive muscle fiber degradation. However, color stability deteriorated markedly, with accelerated declines in redness observed beyond 14 days. Metabolomics analysis demonstrated that storage resulted in a substantial accumulation of lysophospholipids, free amino acids, and nucleotide degradation products, indicative of membrane deterioration, proteolysis, and ATP catabolism. Notably, acetyl-L-carnitine, cysteinylglycine (Cys-Gly), and nicotinamide exhibited progressive depletion, correlating with diminished antioxidant capacity and color deterioration. KEGG pathway enrichment revealed significant alterations in glycerophospholipid, amino acid, and glutathione metabolism. This study provides the first comprehensive metabolomic characterization of donkey meat during chilled storage, identifying potential biomarkers for freshness assessment and offering a scientific foundation for developing targeted preservation interventions.

The advancement of green and low-carbon transition in the steel industry has increased the demand for high-quality direct reduced iron (DRI) as a premium feedstock for electric arc furnace steelmaking. This imposes stricter quality requirements for fired pellets utilized in gas-based shaft furnace processes. To address the poor low-temperature reduction degradation (LTD) of fired pellets produced from a single high-grade magnetite concentrate during gas-based direct reduction. This study investigates the effects of blending hematite concentrates into a magnetite concentrate base (with additions of 0, 20 wt.%, 30 wt.%, and 40 wt.%) on the characteristics of the mixed concentrates, green ball properties, firing performance, and the metallurgical performance of the resulting fired pellets under conditions simulating an HYL shaft furnace. The results indicate that the incorporation of hematite concentrate optimizes the overall particle size distribution and green ball properties. As the hematite proportion increases, the optimal preheating temperature for green balls rises, while the required roasting temperature decreases. The most significant reduction in roasting temperature, from 1225 °C to 1175 °C, is achieved with a 20 wt.% hematite addition. Regarding metallurgical properties, the addition of hematite has a minor effect on the reducibility index (RI) but substantially improves the reduction swelling index (RSI). A notable decrease in the RSI is observed at addition levels of 30% and above. Critically, the LTD is significantly enhanced. The optimal improvement is attained with a 20 wt.% hematite blend, resulting in a- LTD+6.3 mm fraction of 97.48 wt.%, a- LTD−3.2 mm fraction of only 2.18 wt.%, and a whole pellet ratio of 88.01% after reduction. Considering the comprehensive performance, a blend of hematite concentrate between 20 wt.% and 30 wt.% yields fired pellets with superior characteristics, meeting the production requirements for gas-based shaft furnace direct reduction processes. This study provides an effective technological pathway for producing high-performance DRI-grade pellets from high-grade magnetite concentrates, contributing to the green and low-carbon transformation of the iron and steel industry.

The growing demand for direct reduced iron (DRI) in green steel production requires high-quality fired pellets as the burden for the gas-based shaft furnace direct reduction process. However, the properties of magnetite concentrate as pellet feed present a significant impact on the quality of fired pellets, especially the metallurgical performance. A systematic study of the effect of pretreating the magnetite concentrate on the properties of fired pellets was conducted using two pretreatment technologies, i.e., damp-milling and high-pressure roll grinding (HPRG). Green balls were made from pretreated magnetite concentrates and fired under optimal conditions. Their performance was then evaluated in a laboratory-scale setup simulating the HYL shaft furnace environment. Key metrics included cold compressive strength (CCS), reducibility index (RI), reduction swelling index (RSI), and dynamic low-temperature reduction degradation (LTD). The pretreatment of magnetite concentrates with HPRG twice showed significant benefits. The fired pellets not only have a CCS of 2500 N/p at a roasting temperature 150 °C lower, but also achieve an RI of 3.37 and an RSI of 3.15%, respectively. Furthermore, the reduction degradation tendency was markedly reduced; the +6.3 mm fraction reached 94.72% with a whole pellet ratio of 75.49%. Conversely, while damp-milling improved the LTD, it required a 100 °C increase in preheating temperature and yielded a whole pellet ratio of only 49.15%, failing to meet industrial requirements. The improvement in metallurgical performance is attributed to the intense micro-cracking induced by the two-pass HPRG process, which optimizes the particle size distribution, specific surface areas and improves the microstructure and pore properties of the fired pellets.

Ti-bearing blast furnace slag (TBS), a byproduct of vanadium–titanium magnetite smelting, serves as an important secondary resource for titanium recovery. However, the complex mineralogical composition and finely dispersed nature of titanium in TBS present significant challenges for efficient extraction. This review systematically examines four major titanium extraction routes: hydrometallurgical leaching, pyrometallurgical smelting, molten salt electrolysis, and selective precipitation, focusing on their limitations and recent improvements. For instance, conventional acid leaching suffers from acid mist release, a colloidal formation that hinders titanium recovery, and waste acid pollution. The adoption of concentrated sulfuric acid roasting activation effectively suppresses acid mist emission and prevents colloidal generation. Pyrometallurgical approaches are hampered by high energy consumption and substantial carbon emissions, which can be alleviated through the use of gaseous reductants to enhance reaction efficiency and reduce environmental impact. Molten electrolysis faces issues such as polarization and undesirable dendritic deposition; these are mitigated by employing liquid metal cathodes integrated with vacuum distillation to achieve high-purity titanium products. Selective precipitation struggles with strict crystallization conditions and low separation efficiency, though advanced techniques like supergravity separation show improved extraction performance. We propose an integrated technical strategy termed “Online conditioning driven by waste heat-mineral phase reconstruction-directional crystallization-optimized liberation.” This approach utilizes the inherent waste heat of slag combined with electromagnetic stirring to enhance homogeneity and promote efficient titanium recovery, offering a sustainable and scalable solution for industrial TBS treatment.

IntroductionFarmland shelterbelts serve as important ecological barriers that protect agricultural systems. Investigating the effects of shelterbelts with different structural configurations on farmland microclimate is of great significance for optimizing shelterbelt structure and improving farmland ecological stability.MethodsIn this study, structural characteristics including the number of rows, length, spacing, and porosity were comprehensively considered. Three types of shelterbelt configurations (Grade I, II, and III) were selected using a typical sampling method in the 12th Regiment of Alar City, Xinjiang, with open farmland serving as the control (CK). Microclimate factors, including wind speed (WS), air temperature (TA), air humidity (RH), light intensity (LI), and soil temperature (ST), were measured at different horizontal distances from the shelterbelt during four cotton growth stages (Seedling Stage, Budding Stage, Flowering Stage, Boll Opening Stage).ResultsThe results showed that the microclimate-regulating effect of shelterbelts increased with the improvement of shelterbelt grade, generally following the order Grade I > Grade II > Grade III. Among them, Grade I shelterbelts showed the most pronounced wind-speed reduction and hydrothermal regulation effects throughout the whole cotton growth period. The relative wind-speed reduction rate ranged from 72.50% to 97.78%, while the relative interaction index (RII) ranged from −0.164 to 0.010 for LI, from −0.063 to 0.166 for RH, from −0.055 to 0.005 for ST, and from −0.066 to 0.012 for TA. Spatially, wind speed under all three shelterbelt grades reached its minimum at 0.5H and then gradually increased with distance from the shelterbelt. TA was relatively low at 0.5H, and the cooling effect was more pronounced at noon. RH was higher at 1H and gradually approached the control level with increasing distance. LI increased with height in the vertical direction, while its horizontal distribution was relatively stable, with only a slight decrease near the shelterbelt. ST at the 10–15 cm soil layer was lower than that at the 0–10 cm layer, and a low-temperature center occurred horizontally at 2H–3H, with ST generally decreasing as the cotton growth period progressed.DiscussionThis study indicates that shelterbelt structures with more rows, better belt continuity, richer tree species composition, and moderate porosity are more conducive to improving the farmland microclimate. These findings provide a theoretical basis for optimizing farmland shelterbelt structure and regulating microclimate in agroforestry systems in arid regions.