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To reduce environmental pollution and reliance on fossil resources, polyethylene terephthalate as the most consumed synthetic polyester needs to be recycled effectively. However, the existing recycling methods cannot process colored or blended polyethylene terephthalate materials for upcycling. Here we report a new efficient method for acetolysis of waste polyethylene terephthalate into terephthalic acid and ethylene glycol diacetate in acetic acid. Since acetic acid can dissolve or decompose other components such as dyes, additives, blends, etc., Terephthalic acid can be crystallized out in a high-purity form. In addition, Ethylene glycol diacetate can be hydrolyzed to ethylene glycol or directly polymerized with terephthalic acid to form polyethylene terephthalate, completing the closed-loop recycling. Life cycle assessment shows that, compared with the existing commercialized chemical recycling methods, acetolysis offers a low-carbon pathway to achieve the full upcycling of waste polyethylene terephthalate. The recycling of polyethylene terephthalate is of utmost importance to reduce environmental pollution and reliance on fossil resources however, the existing methods do not process colored or blended polyethylene terephthalate materials. Here, the authors demonstrate the acetolysis of waste polyethylene terephthalate into terephthalic acid and simultaneous acidic degradation of dyes and additives

Polymeric materials, rich in carbon, hydrogen, and oxygen elements, present substantial fire hazards to both human life and property due to their intrinsic flammability. Overcoming this challenge in the absence of any flame-retardant elements is a daunting task. Herein, we introduce an innovative strategy employing catalytic polymer auto-pyrolysis before combustion to proactively release CO 2 , akin to possessing responsive CO 2 fire extinguishing mechanisms. We demonstrate that potassium salts with strong nucleophilicity (such as potassium formate/malate) can transform conventional polyurethane foam into materials with fire safety through rearrangement. This transformation results in the rapid generation of a substantial volume of CO 2 , occurring before the onset of intense decomposition, effectively extinguishing fires. The inclusion of just 1.05 wt% potassium formate can significantly raise the limiting oxygen index of polyurethane foam to 26.5%, increase the time to ignition by 927%, and tremendously reduce smoke toxicity by 95%. The successful application of various potassium salts, combined with a comprehensive examination of the underlying mechanisms, underscores the viability of this strategy. This pioneering catalytic approach paves the way for the efficient and eco-friendly development of polymeric materials with fire safety. Overcoming this challenge of fire hazards by carbon, hydrogen, and oxygen rich materials remains challenging. Here, the authors demonstarte that catalytic polymer auto-pyrolysis before combustion releases CO2, equipping the material with fire retardant properties.

The Loess Plateau of China, located to the west of the Liupan Mountains and north of the Qinling Mountains stretching across the Yellow River, is the main loess deposit area in Northwest China. The loess in the northwest of China has deposits with large thickness and extensive distribution. Scanning electron microscopy (SEM) and energy spectrum analysis of loess have been performed to study the relationship between the loess microstructures and the forming climates Era. The relevant indexes were evaluated including the sand‐dropping speed (Vn), certain sedimentary depths (hn sand particle volume (Vd) and element ratios of Ca/Fe, K/Al, Si/Al and Ca/Mg. The microstructure indexes of loess accumulation and evolution reflect paleoclimate conditions and time scales to a certain extent. The important discovery is the microscopic sand‐dropping speed (Vn) and the sedimentary depth hn) calculation method of different sedimentary ages. These indices are compared with the record of major aeolian‐forming climates from the Guliya ice core, and provide a reliable benchmark for studying climate change It also can be used as important indicators of monsoonal change and environmental evolution reconstruction. The index of sand sedimentation speed (Vn) got from loess microstructure could reflect sand‐dropping speed and loess deposition course. According the article can serve as new indicators of climatic changes of different forming loess layers. It can also be concluded that the climatic indexes obtained from loess microstructure can reflect climate conditions of loess forming. The loess forming climatic parameters are synchronous correspond to Tengger Desert and Guliya ice core for studying climate change, then microscopic parameters can also be used for preliminary analysis of loess climate formation and has be found corresponding evidence, and the loess climatic parameters correspond to the other two indexes. The analysis of loess microstructure indexes is very useful in researching climate change. Loess microstructure indexes can find new indicators and information about the monsoon climate evolution and paleoclimate changes. Figure 1 shows the microscopic parameters of loess sampling site diagram. Figure 2 and Figure 3 show the energy spectrum during the maximum glacial period (12 m) and deglaciation period (8 m). Figure 4 and Figure 5 show the microstructure images of Jingtai at 3.5 m. and Jingtai (2–2.5 m). Figure 6 shows the chemical index of samples from two different depths (2 m, 3 m) in Jingtai, Gansu. Figure 7 shows the microstructure of Samples from different depths: Yuzhongi, Lintao samples of 4 m and 6 m, Lintao (8 m) and Yuzhong (8 m); Yuzhong (10 m) and Lintao (12 m), Lintao 16 m and 20 m. Figure 8 shows the climatic index of micro‐structure of loess Q32 in Lintao sand sedimentation speed (Vs), sand particle volume (V), element ratio of grain groups (Si/al, K/al, Ca/Mg, Ca/fe). Figure 9 shows the climatic index in Xiaguanying (Xgy‐Lanzhou) samples. Figure 10 shows the climate reproduction element ratios in different climatic periods. Figure 11 shows the average sand reduction rate, the average particle volume, sand velocity and grain volume in different climatic periods.

Alcoholysis of poly(ethylene terephthalate) (PET) waste to produce monomers, including methanolysis to yield dimethyl terephthalate (DMT) and glycolysis to generate bis-2-hydroxyethyl terephthalate (BHET), is a promising strategy in PET waste management. Here, we introduce an efficient PET-alcoholysis approach utilizing an oxygen-vacancy ( V o )-rich catalyst under air, achieving space time yield (STY) of 505.2 g DMT ·g cat −1 ·h −1 and 957.1 g BHET ·g cat −1 ·h −1 , these results represent 51-fold and 28-fold performance enhancements compared to reactions conducted under N 2 . In situ spectroscopy, in combination with density functional theory calculations, elucidates the reaction pathways of PET depolymerization. The process involves O 2 -assisted activation of CH 3 OH to form CH 3 OH * and OOH * species at V o -Zn 2+ –O–Fe 3+ sites, highlighting the critical role of V o -Zn 2+ –O–Fe 3+ sites in ester bond activation and C–O bond cleavage. Moreover, a life cycle assessment demonstrates the viability of our approach in closed-loop recycling, achieving 56.0% energy savings and 44.5% reduction in greenhouse-gas emissions. Notably, utilizing PET textile scrap further leads to 58.4% reduction in initial total operating costs. This research offers a sustainable solution to the challenge of PET waste accumulation. Polyester waste is increasingly accumulating in the environment, and alcoholysis recycling offers a sustainable management solution. This study demonstrates the use of an oxygen vacancy-rich catalyst to transform waste blended polyester/textiles into high-value monomers.

Landslide disasters occur frequently in the mountainous areas in southwest China, which pose serious threats to the local residents. Interferometry Synthetic Aperture Radar (InSAR) provides us the ability to identify active slopes as potential landslides in vast mountainous areas, to help prevent and mitigate the disasters. Quickly and accurately identifying potential landslides based on massive SAR data is of great significance. Taking the national highway near Wenchuan County, China, as study area, this paper used a Stacking-InSAR method to quickly and qualitatively identify potential landslides based on a total of 40 Sentinel SAR images acquired from November 2017 to March 2019. As a result, 72 active slopes were successfully detected as potential landslides. By comparing the results from Stacking-InSAR with the results from the traditional SBAS-InSAR (Small Baselines Subset) time series method, it was found that the two methods had a high consistency, with 81.7% potential landslides identified by both of the two methods. A detailed comparison on the detection differences was performed, revealing that Stacking-InSAR, compared to SBAS-InSAR may miss a few active slopes with small spatial scales, small displacement levels and the ones affected by the atmosphere, while it has good performance on poor-coherence regions, with the advantages of low technical requirements and low computation labor. The Stacking-InSAR method would be a fast and powerful method to qualitatively and effectively identify potential landslides in vast mountainous areas, with a comprehensive understanding of its specialty and limitations.

Pedestrian detection is widely used in real-time surveillance, urban traffic, and other fields. As a crucial direction in pedestrian detection, dense pedestrian detection still faces many unresolved challenges. Existing methods suffer from low detection accuracy, high miss rates, large model parameters, and poor robustness. In this paper, to address these issues, we propose a lightweight dense pedestrian detection model with finer-grained feature information interaction called MSCD-YOLO, which can achieve high accuracy, high performance and robustness with only a small number of parameters. In our model, the light-weight backbone network MobileViT is used to reduce the number of parameters while efficiently extracting both local and global features; the SCNeck neck network is designed to fuse the extracted features without losing information; and the DEHead detection head is utilized for multi-scale feature fusion to detect the targets. To demonstrate the effectiveness of our model, we conducted tests on the highly challenging dense pedestrian detection datasets Crowdhuman and Widerperson. Compared to the baseline model YOLOv8n, MSCD-YOLO achieved a 4.6% and 1.8% improvement in mAP@0.5, and a 5.3% and 2.6% improvement in mAP@0.5:0.95 on the Crowdhuman and Widerperson datasets, respectively. The experimental results show that under the same experimental conditions, MSCD-YOLO significantly outperforms the original model in terms of detection accuracy, efficiency, and model complexity.

Spin–orbit (SO) coupling leads to numerous phenomena in electron systems. Artificial SO coupling in ultracold neutral atoms provides the opportunity to study such phenomena in bosonic systems, which exhibit superfluidity and various symmetry-breaking condensate phases. In general, a richer structure of symmetry breaking results in a nontrivial finite-temperature phase diagram, but the thermodynamics of the SO-coupled Bose gas at finite temperature remains unknown both in theory and experiment. Here we experimentally determine a new finite-temperature phase transition that is consistent with the transition between the stripe ordered phase and the magnetized phase. We also observe that the magnetic phase and the Bose condensate transitions occur simultaneously as temperature decreases. We determine the entire finite-temperature phase diagram of the SO-coupled Bose gas, thus illustrating the power of quantum simulation. Spin–orbit coupling in Bose gases is expected to lead to new phenomena, but the thermodynamic properties are not yet fully understood. An ultracold atom experiment using artificial spin–orbit coupling uncovers the finite-temperature phase diagram and a transition between a stripe-ordered and a magnetized phase.

The benefits of increasing the number of surface hydroxyls on TiO2 nanoparticles (NPs) are known for environmental and energy applications; however, the roles of the hydroxyl groups have not been characterized and distinguished. Herein, TiO2 NPs with abundant surface hydroxyl groups were prepared using commercial titanium dioxide (ST-01) powder pretreated with alkaline hydrogen peroxide. Through this simple treatment, the pure anatase phase was retained with an average crystallite size of 5 nm and the surface hydroxyl group density was enhanced to 12.0 OH/nm2, estimated by thermogravimetric analysis, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. Especially, this treatment increased the amounts of terminal hydroxyls five- to six-fold, which could raise the isoelectric point and the positive charges on the TiO2 surface in water. The photocatalytic efficiency of the obtained TiO2 NPs was investigated by the photodegradation of sulforhodamine B under visible light irradiation as a function of TiO2 content, pH of solution, and initial dye concentration. The high surface hydroxyl group density of TiO2 NPs can not only enhance water-dispersibility but also promote dye sensitization by generating more hydroxyl radicals.

Dye wastewater is a typical refractory organic wastewater. Advanced oxidation processes have been proven to be an effective way for treating high concentration dye wastewater. This method, which activates peroxymonosulfate (PMS) with cobalt-based catalysts and produces sulfate radicals, has garnered significant research interest. This study developed a highly efficient and environmentally friendly cobalt-based catalysts Co–Ce–Ru/γ-Al 2 O 3 via an impregnation method for enhanced activation of PMS to degrade rhodamine B (RhB) in wastewater. The innovative incorporation of rare-earth metal Ce and precious metal Ru into Co/γ-Al 2 O 3 significantly reduced cobalt loading while improving catalytic activity and stability. The decolorization rate of RhB in dye wastewater was used as the degradation performance index. Results showed that the decolorization rate of RhB using Co–Ce–Ru/γ-Al 2 O 3 catalyst was close to 100% when the system temperature was 25 °C, the amount of catalyst was 0.5 g/L, the amount of PMS was 0.5 g/L, and the concentration of RhB was 50 mg/L. Importantly, the catalyst exhibited exceptional durability with minimal metal leaching (< 1.0 mg/L) over multiple cycles, complying with environmental standards. This work provides deep insights into the catalytic mechanism and kinetics of PMS activation, offering a practical and sustainable solution for the treatment of dye-contaminated wastewater.

Feather waste is the highest protein-containing resource in nature and is poorly reused. Bioconversion is widely accepted as a low-cost and environmentally benign process, but limited by the availability of safe and highly efficient feather degrading bacteria (FDB) for its industrial-scale fermentation. Excessive focuses on keratinase and limited knowledge of other factors have hindered complete understanding of the mechanisms employed by FDB to utilize feathers and feather cycling in the biosphere. Streptomyces sp. SCUT-3 can efficiently degrade feather to products with high amino acid content, useful as a nutrition source for animals, plants and microorganisms. Using multiple omics and other techniques, we reveal how SCUT-3 turns on its feather utilization machinery, including its colonization, reducing agent and protease secretion, peptide/amino acid importation and metabolism, oxygen consumption and iron uptake, spore formation and resuscitation, and so on. This study would shed light on the feather utilization mechanisms of FDBs. Li et a. report a new Streptromyces isolate, SCUT-3 which can efficiently degrade feather into products with high amino acid content, useful as feed for plants, animals and microbes. Using multiple omics and other techniques, they report how SCUT-3 turns on its feather utilization machinery and suggest a number of expressed genes most likely implicated in feather degradation.