This study investigated the co-pyrolysis of polyethylene terephthalate (PET) and chromium-containing slag (CCS) to regulate PET-derived product partitioning and decrease extractable Cr(VI) in the recovered solid residue. Separate single-factor experiments were conducted to examine the effects of PET/CCS mass ratio (30:1–1:40), external reaction atmosphere (N2, CO2, H2), and heating rate (2–10 ℃/min). Increasing the CCS proportion shifted the apparent PET-basis product partitioning from the recovered condensable fraction toward the difference-derived gas fraction, and PET/CCS = 10:1 was selected as a representative condition for subsequent comparisons. The H2 atmosphere produced the lowest extractable Cr(VI) concentration, corresponding to a concentration-based apparent decrease of approximately 84.5%, while the highest observed decrease among the investigated heating rates was 86.5% at 2 ℃/min. GC-TCD and area-normalized Py-GC/MS analyses revealed condition-dependent changes in outlet-gas composition and organic-product fingerprints. Model-oxide experiments with MgO, Al2O3, CaO, and Cr2O3 produced component-specific responses, with the CaO system showing a lower normalized CO2 fraction and MgO altering the PET mass-loss profile. Potential downstream routes include heat or power generation from the combustible components of the gas and recovered condensable liquid and material utilization of the carbonaceous mineral residue after evaluation of fuel properties, emissions, chromium speciation, and leaching stability. Overall, PET-CCS co-pyrolysis simultaneously regulated PET-derived product partitioning and decreased extractable Cr(VI) in the recovered solid residue, achieving a maximum concentration-based apparent decrease of 86.5% and a residual concentration of approximately 44 mg/kg at 2 ℃/min.
This study investigates the formation of electrical fluting erosion on bearing surfaces using a lubricated ball-on-disc tribometer. The “washboarding effect” is firstly proposed to account for fluting evolution during electrical erosion. Results show that elevated voltage extends the discharge region beyond the Hertzian contact area. Thicker oil films, resulting from higher velocity or viscosity, increase the critical breakdown voltage and decrease the fluting spacing. Additionally, mechanical-electrical coupling under slide-roll conditions significantly exacerbates surface degradation. Fluting is observed to evolve from initial frosting damage. Analogous to the “washboard” phenomenon on the unpaved roads, it is thought the initial ridge/flute morphology is irreversibly recorded and progressively amplified under follow-up rolling, forming fluting erosion with alternating “bright” and “dark” areas.
Benzo[a]pyrene (BaP) contamination in highly saline environments has received increasing attention; however, efficient degradation of BaP by halotolerant BaP-degrading bacteria from contaminated water and soils remains poorly understood. In this study, a novel BaP-degrading bacterium, designated Rhodococcus ruber TN-1, was isolated, and its BaP degradation performance was evaluated. Whole-genome sequencing revealed genes and gene clusters associated with benzoate and xylene transport and degradation, naphthalene degradation, and the catabolism of other aromatic compounds. Strain TN-1 exhibited high BaP degradation efficiency in water, with a degradation efficiency exceeding 95% after 3 d of cultivation. Inoculation with strain TN-1 significantly improved the BaP degradation efficiency in three types of saline soil. After 14 d of reaction, the BaP degradation rate increased from 12.08% to 26.94% in the control to 44.03–59.12%. Correlation analysis revealed that the degradation rate of soil BaP was positively correlated with soil catalase (CAT) activity and negatively correlated with salinity. Metagenomic and quantitative real-time PCR (qPCR) analyses demonstrated that the addition of strain TN-1 significantly increased microbial abundance in three saline soils, with strain TN-1 becoming the dominant microorganism and accelerating the microbial degradation of BaP. These findings highlight strain TN-1 as a promising bioaugmentation agent for the remediation of BaP-contaminated saline soils.
Besides improving environmental conditions, large scale ecological restoration initiatives carry implications for households' livelihoods. Therefore, evaluating whether restoration policies can align ecological objectives with income growth is important for promoting environmentally sustainable development. We study whether China's Integrated Protection and Restoration Project of Mountains, Rivers, Forests, Farmlands, Lakes, Grasslands, and Deserts, commonly known as the Shan-Shui Initiative, has helped promote rural income growth as well as the channels through which income effects operate. Using a panel of 1700 counties from 21 provinces, we estimate policy effects for the period 2016-2022 with a synthetic control approach that uses machine learning to construct counterfactual income paths for treated counties. Our results show that the initiative has increased rural incomes with gains growing over time. Estimated effects differ by pilot batch, with incomes rising by about 5% and 1.9% for the first two project cohorts implemented in 2016 and 2017, respectively, but decreasing by 0.9% for the final batch in 2018. After adjusting for potential anticipation effects, the estimated effect for the 2017 cohort increases to 3.7%. We demonstrate that ecological restoration promotes rural incomes via improvements in ecosystem services, infrastructure, and tourism development. Income effects are generally larger in more economically developed and less ecologically fragile areas, while differences across dominant project types are comparatively modest. The results provide insights into potential policies for aligning environmental protection objectives with rural development.
To address insufficient contrast of fixed markers, boundary-information degradation during feature upsampling, and local fluctuations in frame-wise localization results during long-distance bridge displacement measurement, this study proposes a vision-based bridge displacement measurement network, DT-Net. The network consists of an adaptive brightness-contrast enhancement module (ABCE), an HSD-Net localization network with a measurement-aware dynamic sampling module (MDSF), and a cross-frame displacement-trajectory refinement module (DBATrack). ABCE enhances marker boundaries and local details while limiting background-noise amplification through denoising, local contrast enhancement, and detail modulation. MDSF uses measurement response, structural cue, and reliability information to regulate and constrain dynamic sampling offsets, thereby improving the preservation of displacement-sensitive boundary features and coordinate-estimation stability. DBATrack integrates candidate-position aggregation, cross-frame association, and adaptive trajectory refinement to reduce local fluctuations and improve the continuity of displacement sequences. DT-Net was validated through an indoor cable-stayed bridge model experiment and a field experiment on the Longjiang Bridge. In the indoor experiment, DT-Net achieved a mean normalized root mean square error (mNRMSE) of 0.0238 across two measurement points. Under normal field conditions, it achieved a root mean square error (RMSE) of 1.1928 mm at an observation distance of approximately 102 m. Under the constructed illumination disturbances and camera vibration, the displacement measurements obtained by DT-Net remained in good agreement with the Reference, and the dominant long-period component of the field displacement response was also consistently captured. These results demonstrate the effectiveness of DT-Net for bridge displacement measurement under the evaluated indoor and long-distance field conditions.
