Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2024122406
The effects of different vegetation types on soil quality in the Green Heart Area of the Changsha-Zhuzhou-Xiangtan City Cluster were evaluated to provide a reference for selecting suitable afforestation species and improving forest soil quality. Seven vegetation types (mixed forest, broad-leaved forest, coniferous forest, economic forest, shrub forest, grassland, and abandoned cropland) with similar site conditions were studied. Eleven soil physicochemical indicators were measured, and soil quality was assessed using principal component analysis (PCA), Pearson correlation, total data set (TDS), minimum data set (MDS), and entropy-weighted TOPSIS methods. Results showed no significant differences in soil water content, soil bulk density, and C:N ratio among vegetation types, while significant differences were found in total porosity, capillary porosity, saturated water content, field water holding capacity, total carbon, total nitrogen, available potassium, and available phosphorus. Compared with abandoned cropland, soil water content, total porosity, field water holding capacity, saturated water content, total carbon, total nitrogen, available potassium, and available phosphorus were significantly higher, and soil bulk density was significantly lower. Mixed forest soil exhibited the highest values for field water holding capacity, total porosity, saturated water content, total nitrogen, total carbon, available potassium, and available phosphorus. Correlation analysis revealed that soil bulk density was extremely significantly negatively correlated with soil water content, total porosity, and saturated water content, and significantly negatively correlated with field water holding capacity, total carbon, and total nitrogen. Soil capillary porosity, field water holding capacity, total porosity, and saturated water content were extremely significantly positively correlated with soil nutrients, while soil bulk density showed varying degrees of negative correlation with soil chemical nutrients. Soil chemical properties and stoichiometric ratios showed varying degrees of significant positive correlation. The order of soil quality under different vegetation types was mixed forest > broad-leaved forest > shrub forest > economic forest > grassland > coniferous forest > abandoned cropland. Mixed forest soil quality was the best and significantly higher than other vegetation types, with significant differences among vegetation types. Mixed forest soil quality was clearly superior. In vegetation restoration and plantation establishment in the Green Heart Area, the principle of matching tree species to site conditions should be followed, with a focus on mixed forests to improve overall soil quality and enhance ecological benefits of artificial vegetation restoration.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4061-5
The dynamic modulation of magnetic properties by external stimuli represents a paradigm shift in materials science, enabling non-contact, reversible control of spin states for applications in optical switching, sensing, and low-power spintronics. Prussian blue analogues (PBAs) are versatile platforms for photo-responsive magnetism, yet their photomagnetic response is highly sensitive to transition metal selection, alkali ions, vacancies, and water content, complicating targeted synthesis. Here, we introduce a generalizable strategy by incorporating the photo-responsive organic cation methyl viologen (MV2+) into PBA frameworks, yielding hybrids MVPB, MVPB-Co, and MVPB-Ni. Upon Xe lamp irradiation, MV2+ undergoes reduction to the radical cation MV+•, which acts as a spin carrier coupling to the magnetic moments of the metal ions. This mechanism decouples the photomagnetic response from the inorganic lattice, overcoming stoichiometric limitations. Irradiation leads to a substantial enhancement of magnetization, followed by partial relaxation under prolonged exposure, attributed to the generation and accumulation of MV+• radicals. These radicals function as dynamic magnetic modifiers, distinct from conventional light-induced charge transfer in PB frameworks. The approach is applicable across diverse cyanide-bridged metal pairs, irrespective of alkaline cations, vacancies, or water content, establishing a robust route for designing light-responsive magnetic materials.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025032801
A highly sensitive and accurate method using liquid-liquid extraction (LLE) coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for simultaneous quantification of nine neonicotinoid insecticides and their metabolites in human urine and serum. Samples underwent enzymatic hydrolysis followed by ethyl acetate extraction, effectively enriching target analytes. Gradient elution and optimized mass spectrometry conditions enabled simultaneous determination. The method exhibited excellent linearity with correlation coefficients >0.999. In urine, limits of detection (LOD) ranged from 0.001 to 0.010 μg·L−1 and limits of quantification (LOQ) from 0.004 to 0.035 μg·L−1. In serum, LODs were 0.0004–0.02 μg·L−1 and LOQs 0.0014–0.07 μg·L−1. Average spiked recoveries were 89.3%–115.0% in urine and 83.0%–115.0% in serum, with relative standard deviations (RSD) of 0.5%–8.0% and 2.5%–9.5%, respectively. Analysis of paired urine and serum samples from 123 Guangzhou residents revealed detection rates of 94.3%–100% for the nine analytes in urine, with clothianidin showing the highest median concentration (1.89 μg·L−1). In serum, detection rates for clothianidin, thiacloprid, acetamiprid, imidacloprid-olefin, and 5-hydroxy-imidacloprid were below 60%, while the remaining four analytes ranged from 74.8% to 99.2%. Urinary concentrations of all nine analytes were significantly higher than serum concentrations (P<0.05). Significant positive correlations between urine and serum concentrations were observed for clothianidin, thiamethoxam, imidacloprid, and N-desmethyl-acetamiprid, with N-desmethyl-acetamiprid showing the strongest correlation. The LLE-UPLC-MS/MS method efficiently and accurately detects neonicotinoids and metabolites in urine and serum, providing a reliable tool for human exposure assessment.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025032704
Chlorogenic acid (CGA), a key component of the anti-COVID drug Lianhua Qingwen, is recalcitrant to biodegradation and tends to bioaccumulate, posing risks to aquatic ecosystems. Conventional water treatment methods are inadequate for its removal. This study investigated the degradation of CGA using a magnetic field coupled Fe-C activated persulfate (MF/Fe-C/PS) advanced oxidation process. The degradation efficiencies of Fe-C, PS, Fe-C/PS, and MF/Fe-C/PS systems were compared, and the dominant reactive species and their contributions were identified. The effects of initial pH, persulfate (PS) concentration, Fe-C dosage, and inorganic anions on degradation kinetics were examined, along with the degradation pathway and disinfection byproduct (DBP) formation potential. Results showed that MF/Fe-C/PS achieved 99% degradation of CGA within 60 min under optimal conditions: pH=3, PS concentration 1.5 mmol·L−1, and Fe-C dosage 0.4 g·L−1. Coexisting Cl−, Br−, and I− inhibited CGA oxidation to varying degrees, as did natural organic matter (FA and BAS). The reactive species SO4−·, ·OH, and 1O2 contributed 41.6%, 30.5%, and 27.9%, respectively. Degradation mechanisms included hydrolysis, dehydroxylation, decarboxylation, and benzene ring cleavage. Pre-oxidation by MF/Fe-C/PS significantly reduced the DBP formation potential during subsequent chlorination/chloramination. Energy per order (EE/O) analysis indicated favorable economic efficiency.