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In this study, we selected walnut shell-derived pristine HC (pHC) and two modified derivatives obtained by oxidative and alkali treatments (designated mHC-O and mHC-A, respectively) to investigate the passivation performance of Pb(II) in contaminated soil. The yields of mHC-A and mHC-O were 70.58% and 95.38%, respectively, after posttreatment. According to the XPS, FTIR, and acidity titration results, the amounts of the three major OCGs (i.e. C−O, C=O, and O−C=O) all increased after H2O2 oxidation. Moreover, chemical modification fundamentally changed the structural characteristics of pHC. DTPA extraction tests indicated that the extractable Pb content after 30 days of incubation decreased by 13.60%, 19.32% and 14.53% at 7% (w/w) doses of HC, mHC-O and mHC-A, respectively, compared to that of the control. Furthermore, mHC-O was superior to pHC and mHC-A in terms of Pb passivation efficiency, which was consistent with the results of BCR sequential extraction and leaching tests using three root exudates. For mHC-O at the 7% dose, the contents of bioavailable Pb in the contaminated soil were 19.85 and 8.83 mg/kg based on DTPA leaching and BCR analysis, respectively, while they were 0.616, 0.564 and 0.07 mg/kg in the root exudate leaching tests of Ophiopogon japonicus, radish and spinach, respectively, indicating that the root exudate leaching method lowered the bioavailable Pb content compared to the DTPA and BCR methods. Overall, Oxidation posttreatment with HC could improve the passivation of Pb in contaminated soils. [ABSTRACT FROM AUTHOR]

AbstractThis study aimed to establish a mechanical model for curved tempered vacuum glazing (CTVG) based on thin shells theory. By utilizing the windshield of a specific vehicle as a research object, the ANSYS mechanical simulation model for CTVG was developed. Additionally, CTVG samples were prepared and subjected to wind load performance testing. The simulation results demonstrated that the maximum support stress sustained by the CTVG reached 55.807 MPa, accompanied by a maximum glass deformation of 27.756 μm, both of which satisfied the safety requirements. Furthermore, the analysis of the mechanical model revealed that the maximum surface stress of the CTVG under wind load was directly proportional to the square of the wind speed. The CTVG was capable of withstanding a maximum wind pressure of 1.99 kPa and a maximum wind speed of 56.427 m·s−1, and would be safely deployed at a vehicle speed of 203 km·h−1. The wind load performance test results indicated that the observed trend in the maximum surface stress of the CTVG closely aligned with the theoretically predicted values, deviating within a range of 2.7 MPa. This correspondence signified the reliability and validation of our developed mechanical model. Consequently, this research served as a foundational reference for the advancement and utilization of CTVG products, which would play a beneficial role in reducing vehicle energy consumption when used as automotive window glass in the future. [ABSTRACT FROM AUTHOR]