The Chinese Journal of Process Engineering•2026•DOI: 10.12034/j.issn.1009-606X.225185
Sulfur hexafluoride (SF6), widely used as an insulating gas in high-voltage electrical equipment, possesses a global warming potential (GWP) 25,200 times that of CO2, necessitating efficient degradation technologies. This study employed computational fluid dynamics (CFD) to simulate the thermal catalytic degradation of SF6 in a fixed-bed reactor, integrating models for porous media, heat transfer, turbulence, and chemical kinetics. The simulations revealed significant radial non-uniformities in pressure, velocity, temperature, and species concentration distributions, with temperature identified as the dominant factor influencing degradation efficiency. Radial temperature gradients caused uneven reaction rates, with degradation rates near the wall substantially exceeding those at the central axis, thereby reducing overall SF6 conversion. To address this, structural optimizations were implemented, including reducing the reactor tube diameter and incorporating inert porous media with high thermal conductivity at both ends of the catalytic section. These modifications enhanced radial heat transfer, homogenized the temperature field, and improved the uniformity of reaction rates and species concentrations. Parametric studies on inlet gas velocity showed that both excessively low and high flow rates were detrimental: low velocities led to underutilization of the downstream catalyst and increased energy consumption, while high velocities deteriorated heat transfer and exacerbated radial temperature gradients. The optimal inlet velocity range was determined to be 0.4–0.8 m/s for a reactor tube inner diameter of 10 mm, balancing catalyst utilization, energy consumption, and degradation efficiency. This research provides data-driven guidance for the design and scale-up of SF6 catalytic degradation reactors.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026051001
Haikou, a representative tropical city in China, experiences air pollution influenced by both local emissions and regional transport. This study analyzed O3 and PM2.5 concentrations, emission sources, and meteorological fields from Haikou and Guangdong-Guangxi cities in 2024, employing correlation analysis and the Weighted Potential Source Contribution Function (WPSCF) to systematically investigate spatial-temporal patterns, regional linkages, and transport mechanisms. Results revealed distinct pollution characteristics: Hainan exhibited prominent O3 pollution in autumn and winter, while the Pearl River Delta (PRD) in Guangdong suffered significant O3 pollution year-round, positioning it as the core control area. Guangxi was characterized by severe PM2.5 pollution in winter with extensive high concentration areas. Haikou's O3 and PM2.5 concentrations showed strong correlations with those in Zhanjiang and Maoming throughout the year, particularly in winter. Regional transport analysis indicated that O3 pollution in Haikou depended on stable cross-regional precursor transport coupled with intense photochemical conditions, whereas PM2.5 exhibited diverse transport pathways across seasons. Lag effect analysis confirmed that pollution exceedance days were substantially influenced by upwind transport from the previous day, highlighting the dominant role of cross-regional physical transport. Autumn pollution was driven by stable surface northeasterly winds and upper-level uniform pressure fields. Potential source areas were highly consistent with the MEIC emission inventory, confirming distinct contributions of transport pathways for O3 and PM2.5. These findings provide a scientific basis for differentiated collaborative control of air pollution in tropical coastal cities.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4085-9
Bone defects remain a prevalent clinical challenge, and regenerative medicine based on bone tissue engineering offers promising solutions. Traditional osteogenic materials rely on bioactive macromolecules like growth factors, which suffer from poor stability and stringent storage requirements. From a structural perspective, bone tissue resides in a phosphorylated microenvironment, with 65–70% of inorganic components composed of hydroxyapatite. Inorganic phosphorylated materials induce osteogenic differentiation but exhibit high stiffness, brittleness, slow degradation, and limited mechanical tunability. Synthetic phosphorylated polymers with excellent mechanical properties and biocompatibility have been developed to address these issues. In this work, we developed a series of phosphorylated polymers derived from poly(glycerol sebacate) (PGS), a biocompatible and biodegradable material. Leveraging the hydroxyl-rich backbone of PGS, we demonstrated an efficient method for controllable phosphorylation of PGS side chains, enabling synthesis of PGS-based phosphorylated (PGS-P) polymers with tunable phosphorus contents. The optimized phosphorylated polyester, PGS-P4, exhibited strong ability to promote osteogenic differentiation of rat BMSCs, and its porous three-dimensional scaffolds showed favorable properties for bone regeneration. BMSCs cultured for one week and observed by fluorescence microscopy showed enhanced BSP protein expression on PGS-P2, PGS-P4, and PGS-P6 groups compared with PLGA and PGS, with PGS-P4 displaying the most intense signal. In summary, we present a simple and controllable method for preparation of functionalized polyesters and their porous scaffolds with tunable phosphorus content, validating its effectiveness in promoting osteogenic differentiation of rat BMSCs. All phosphorylated polyesters exhibit enhanced differentiation-promoting effects compared to non-phosphorylated PGS; however, the degree of enhancement does not increase monotonically with phosphorus content. PGS-P4, containing an optimal phosphorus level, shows the most pronounced biological functions.