Sustainable rice production in trace element-contaminated farmlands requires management strategies that simultaneously reduce grain metal accumulation and greenhouse gas emissions while maintaining yield. This study aims to evaluate how different fertilizer types-nitrogen, phosphorus, and potassium-affect these sustainability indicators in a rice-caixin rotation system. A pot experiment was conducted with trace element contaminated soil cultivated with two rice varieties, conventional Xiangzaoxian 45 (Oryza sativa L. subsp. Indica, Rice A) and hybrid Pengyou 1269 (Oryza sativa L. subsp. Indica, Rice B). Two rice–caixin rotation systems (A-G and B-G) were established by alternating Rice A and B with caixin (Brassica rapa var. parachinensis ‘Zengcheng Chicaixin’). The treatments were urea, calcium-magnesium phosphate, potassium chloride and unfertilized control. The total zinc concentration in the soil of Rice A was decreased by 41.28
In this work, polyethyleneimine (PEI)-functionalized multi-walled carbon nanotubes (PEI@MWCNTs) were synthesized by coating pristine MWCNTs with PEI. Subsequently, mixed matrix membranes (MMMs) containing various loadings of PEI@MWCNTs were fabricated by incorporating the aminated nanotubes into FFBA (a fluorinated copolyimide, synthesized from 6FDA, FPPAB, and BAMF) matrix. This modification strategy takes advantage of the low-diffusion-resistance tubular structure of MWCNTs to facilitate gas transport, while the abundant amino groups of PEI serve as active sites for CO2 molecules. The PEI@MWCNTs/FFBA MMMs exhibited superior thermal stability compared with the pristine FFBA membrane. X-ray diffraction (XRD) analysis revealed that the incorporation of carbon nanotubes expanded the interchain spacing within the PI matrix, thereby increasing the free volume of the membrane. Gas permeation tests showed that, at a PEI@MWCNTs loading of 3 wt
In this study, the shrinkage evolution characteristics of Red Clay under Wetting–Drying Cycles were systematically analyzed through laboratory tests. The results indicate that the shrinkage deformation of Red Clay exhibits an S-shaped nonlinear growth trend characterized by "fast first and then slow". Specifically, it can be divided into three stages: during the initial response stage, samples with high water content and low dry density exhibit larger shrinkage increments; a significant transition occurs during the rapid change stage; and in the stabilization stage, it completely transforms into the opposite correspondence. To address the prediction challenges posed by the small-sample size and high volatility, an Empirical Bayes residual-corrected grey prediction model, EBGM(1,1), was constructed. The results indicate that, across the entire sample, the Mean Absolute Percentage Error (MAPE) for both the linear and volumetric shrinkage rates of the modified model decreased by approximately 50
This study presents a green one-pot hydrothermal strategy to simultaneously convert passion fruit peel (PFP) waste into both fluorescent carbon dots (PFP-CDs) for Cr(VI) detection and biochar (PFP-BC) for Cr(VI) removal. The as-prepared blue-emitting PFP-CDs are 2–5 nm in size, well-dispersed, and rich in surface oxygenated groups, enabling them to function as a Cr(VI)-selective probe via inner filter effect and complex formation. This probe demonstrates a proportional response over concentrations ranging between 0 and 184 µM, with a minimum detectable concentration of 1.174 µM. The simultaneously prepared PFP-BC exhibits a porous morphology and plentiful surface functional groups, along with favorable adsorption performance toward Cr(VI), achieving an uptake capacity of 36.5 mg/g and maintaining good cycling stability. The sorption process follows the pseudo-second-order rate equation and fits well with the Freundlich equilibrium model, and is identified as a spontaneous exothermic process. This work establishes an integrated “waste-to-bifunctional-material” conversion system, offering a sustainable solution for the simultaneous monitoring and remediation of heavy metals.
To address the paucity of functional studies on acidic polysaccharide fractions, the present study focused on the structural identification and immunomodulatory effects of acidic polysaccharides derived from Cinnamomum cassia (L.) J. Presl. Specifically, two acidic polysaccharide fractions (WCP-1 F and WCP-2 F) were extracted from the cinnamon samples using alcoholic precipitation and further purified. The molecular masses of WCP-1 F and WCP-2 F were 846 kDa and 64 kDa, respectively. The polysaccharides of WCP-1 F were predominantly composed of rhamnose, galacturonic acid, galactose, and arabinose, exhibiting molar ratios of 1.48:5.02:1.00:1.80. The WCP-2 F polysaccharides were predominantly composed of rhamnose, mannose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose, with molar ratios of 0.30:0.38:0.17:0.55:0.48:1.00:1.24. The mean total sugar content was 61.29 ± 1.41
