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Raman and surface-enhanced Raman scattering (SERS) spectroscopy are highly specific and sensitive optical modalities that have been extensively investigated in diverse applications. Noise reduction is demanding in the preprocessing procedure, especially for weak Raman/SERS spectra. Existing denoising methods require manual optimization of parameters, which is time-consuming and laborious and cannot always achieve satisfactory performance. Deep learning has been increasingly applied in Raman/SERS spectral denoising but usually requires massive training data, where the true labels may not exist. Aiming at these challenges, this work presents a generic Raman spectrum denoising algorithm with self-supervised learning for accurate, rapid, and robust noise reduction. A specialized network based on U-Net is established, which first extracts high-level features and then restores key peak profiles of the spectra. A subsampling strategy is proposed to refine the raw Raman spectrum and avoid the underlying biased interference. The effectiveness of the proposed approach has been validated by a broad range of spectral data, exhibiting its strong generalization ability. In the context of photosafe detection of deep-seated tumors, our method achieved signal-to-noise ratio enhancement by over 400%, which resulted in a significant increase in the limit of detection thickness from 10 to 18 cm. Our approach demonstrates superior denoising performance compared to the state-of-the-art denoising methods. The occlusion method further showed that the proposed algorithm automatically focuses on characterized peaks, enhancing the interpretability of our approach explicitly in Raman and SERS spectroscopy.

Chemical recycling technologies hold promising potential in converting mixed plastic waste into energy and chemicals. This study proposed a simulation-based quantitative life cycle sustainability assessment framework for the potential plastic waste valorization processes. Sustainability metrics including environment, economy, safety, society, and energy were quantified and comprehensively investigated. Based on the Bayesian best-worst weighting and vector-based ranking methods, the normalized and weighted life cycle sustainability scores were used to prioritize the best process. Gasification-based technology was found superior than incineration-based technology, especially in the economic, techno-energetic, and social aspects. However, incinerated-based process with direct CO2emissions performed better in the environmental aspects compared with the process integrating with carbon capture and utilization unit. Additional environmental burdens were brought to the system when incorporating the carbon capture and methanol synthesis process. Increased system complexity might bring unexpected environmental burdens, and sometimes even outweighed the benefits. Various weights were assigned to the multi-criteria decision-making model, and the gasification-based process consistently ranked first across all scenarios.

Graphene-based two-dimensional (2D) heterostructures exhibit excellent mechanical and electrical properties, which are expected to exhibit better performances than graphene for nanoelectromechanical pressure sensors. Here, we built pressure sensor models based on suspended heterostructures of graphene/h-BN, graphene/MoS2, and graphene/MoSe2by using COMSOL Multiphysics finite element software. We found that suspended circular 2D membranes show the best sensitivity to pressures compared to rectangular and square ones. We simulated the deflections, strains, resonant frequencies, and Young’s moduli of suspended graphene-based heterostructures under the conditions of different applied pressures and geometrical sizes, built-in tensions, and the number of atomic layers of 2D membranes. The Young’s moduli of 2D heterostructures of graphene, graphene/h-BN, graphene/MoS2,and graphene/MoSe2were estimated to be 1.001 TPa, 921.08, 551.11, and 475.68 GPa, respectively. We also discuss the effect of highly asymmetric cavities on device performance. These results would contribute to the understanding of the mechanical properties of graphene-based heterostructures and would be helpful for the design and manufacture of high-performance NEMS pressure sensors.

Iron–nitrogen–carbon (Fe–N–C) materials have been identified as a promising class of platinum (Pt)-free catalysts for the oxygen reduction reaction (ORR). However, the dissolution and oxidation of Fe atoms severely restrict their long-term stability and performance. Modulating the active microstructure of Fe–N–C is a feasible strategy to enhance the ORR activity and stability. Compared with common 3d transition metals (Co, Ni, etc.), the 4d transition metal atom Nb has fewer d electrons and more unoccupied orbitals, which could potentially forge a more robust interaction with the Fe site to optimize the binding energy of the oxygen-containing intermediates while maintaining stability. Herein, an asymmetric Fe–Nb diatomic site catalyst (FeNb/c-SNC) was synthesized, which exhibited superior ORR performance and stability compared with those of Fe single-atom catalysts (SACs). The strong interaction within the Fe–Nb diatomic sites optimized the desorption energy of key intermediates (*OH), so that the adsorption energy of Fe–*OH approaches the apex of the volcano plot, thus exhibiting optimal ORR activity. More importantly, introducing Nb atoms could effectively strengthen the Fe–N bonding and suppress Fe demetalation, causing an outstanding stability. The zinc–air battery (ZAB) and hydroxide exchange membrane fuel cell (HEMFC) equipped with our FeNb/c-SNC could deliver high peak power densities of 314 mW cm–2and 1.18 W cm–2, respectively. Notably, the stable operation time for ZAB and HEMFC increased by 9.1 and 5.8 times compared to Fe SACs, respectively. This research offers further insights into developing stable Fe-based atomic-level catalytic materials for the energy conversion process.

•Technologies for cathode and electrolyte recovery from spent lithium-ion batteries are reviewed.•Various national polices and regulations on battery recycling are summarized.•Practical industrial recycling processes for spent lithium-ion batteries are summarized.•Suggestions for recovery application technologies in industrial process are proposed.

Butanone and ethyl acetate are widely used in chemical production and separation. They are usually used together in actual production. Therefore, it also appears in the waste water. Butanone and ethyl acetate will inevitably form three binary azeotropes with water, rendering their separation very difficult. In this study a butanone/water/ethyl acetate ternary azeotropic system is separated by an extractive distillation process. The extractant is screened by relative volatility and toxicity analysis. The optimal process parameters are obtained based on a genetic algorithm by minimizing annual total cost, achieving an efficient separation of the butanone/water/ethyl acetate ternary azeotropic system. Based on the thermodynamic analysis of the extractive distillation process, the separation process is improved and optimized to achieve a maximum utilization efficiency of energy. The annual total cost and pollutant emissions are studied and analyzed. The optimized extractive distillation process can significantly reduce the energy consumption and pollutant emissions, improve the thermodynamic efficiency and economy. The efficient and energy-saving extraction distillation process based on thermodynamic analysis provides a viable option towards an environmentally benign industry.

Synergistic optimization of donor-acceptor blend morphologyis a hurdle in the path of realizing efficient non-fullerene small-molecule organic solar cells (NFSM-OSCs) due to the anisotropic conjugated backbones of both donor and acceptor. Therefore, developing a facile molecular design strategy to effectively regulate the crystalline properties of photoactive materials, and thus, enable the optimization of blend morphology is of vital importance. In this study, a new donor molecule B1, comprising phenyl-substituted benzodithiophene (BDT) central unit, exhibits strong interaction with the non-fullerene acceptor BO-4Cl in comparison with its corresponding thiophene-substituted BDT-based material, BTR. As a result, the B1 is affected and induced from an edge-on to a face-on orientation by the acceptor, while the BTR and the acceptor behave individually for the similar molecular orientation in pristine and blend films according to grazing incidence wide angle X-ray scattering results. It means the donor-acceptor blend morphology is synergistically optimized in the B1 system, and the B1:BO-4Cl-based devices achieve an outstanding power conversion efficiency (PCE) of 15.3%, further certified to be 15.1% by the National Institute of Metrology, China. Our results demonstrate a simple and effective strategy to improve the crystalline properties of the donor molecule as well as synergistically optimize the morphology of the all-small-molecule system, leading to the high-performance NFSM-OSCs.

Ambient air samples were collected in Brisbane (Australia), Dalian (China), and Hanoi (Vietnam) during Mar 2013–Feb 2018 using polyurethane foam based passive air samplers. A sampling rate calibration experiment was conducted for chlorinated paraffins (CPs, i.e., short-chain, medium-chain, and long-chain CPs), where the sampling rates were 4.5 ± 0.7, 4.8 ± 0.3, and 4.8 ± 2.1 m3day–1for SCCPs, MCCPs, and LCCPs, respectively. The atmospheric concentration of CPs was then calculated and the medians of ∑CPs were 0.079, 1.0, and 0.89 ng m–3in Brisbane, Dalian, and Hanoi, respectively. The concentration of CPs in Brisbane’s air remained at low levels, with no significant differences observed between the city background site and the city center site, indicating limited usage and production of CPs in this city. The highest concentration of MCCPs was detected in Dalian, while the highest concentration of SCCPs was detected in Hanoi. A decrease of SCCP concentration and an increase of MCCPs’ were found in Brisbane’s air from 2016 to 2018, while increasing trends for both SCCPs and MCCPs were observed in Dalian. These results indicated impacts from different sources of CPs in the investigated cities.

Physics-Informed Machine Learning (PIML) is an emerging computing paradigm that offers a new approach to tackle multiphysics modeling problems prevalent in the field of chemical engineering. These problems often involve complex transport processes, nonlinear reaction kinetics, and multiphysics coupling. This Review provides a detailed account of the main contributions of PIML with a specific emphasis on modeling momentum transfer, heat transfer, mass transfer, and chemical reactions. The progress in method development (e.g., algorithm and architecture), software libraries, and specific applications (e.g., multiphysics coupling and surrogate modeling) are detailed. On this basis, future challenges highlight the importance of developing more practical solutions and strategies for PIML, including turbulence models, domain decomposition, training acceleration, surrogate modeling, hybrid modeling, and geometry module creation.

Fermentation is the key technology for black tea aroma formation. The key aroma substances of black tea at different fermentation stages (unfermented (WDY), underfermented (F1H), fully fermented (F4H), and overfermented (F8H)) were characterized by the methodology of Sensomics. Aroma extract dilution analysis was performed on volatile fractions extracted by using solvent-assisted flavor evaporation and solid-phase microextraction, yielding 93 odor-active areas. Internal standard method plus stable isotope dilution analysis was used for quantitative analysis. The omission experiment identified 23 aroma substances. Further reduction and addition experiments revealed phenylacetaldehyde, (E,E)-2,4-heptadienal, geraniol, linalool, β-damascenone, 2-methylbutyraldehyde, dimethyl sulfide, and isovaleraldehyde with odor activity values (OAV) > 100 as the characteristic aroma components of F4H and also as the main contributors to aroma differences between different fermentation degrees. The green odor of (E,E)-2,4-heptadienal was highlighted in WDY and F1H relative to that in F4H due to the lower contribution of phenylacetaldehyde and β-damascenone in the former two samples. Additionally, excessive OAV increase of fatty aldehydes in F8H masked its similar floral and fruity aroma.

Semiconductor photocatalysis offers a promising and sustainable avenue for wastewater treatment due to its ease of separation and recyclability. However, their practical application is currently hampered by limited energy utilization, insufficient mineralization, and low treatment capacity under sunlight. This account summarizes our progress in developing broad-spectrum responsive (extended to 950 nm) supramolecular organic photocatalysts capable of sunlight-driven over 95% pollutant mineralization. Through modulation of molecular dipole and crystallinity, we enhance the built-in electric field, thereby improving charge separation and photodegradation rates. Furthermore, to overcome the low-flux constraints of traditional photocatalysis, we integrated the Fenton catalyst to construct photo-self-Fenton systems, realizing a 29.63 L m2h1high-flux mineralization under sunlight. Finally, a brief conclusion and outlook on organic photocatalysts have also been presented.

A stronger interlayer magnetic coupling (ILMC) can open up new opportunities in spintronic devices. Numerous publications have demonstrated that ILMC is continuously evolving, even in the context of magnetic phase change. Here, we observe an extraordinary discontinuous transition (ILMC spike) in a two-dimensional (2D) van der Waals (vdW) material, Fe5GeTe2(F5GT). The ILMC spikes from 1.15 to 12.79 meV/f.u when a 3% in-plane biaxial strain is applied. Additionally, the applied in-plane strain significantly enhances the magnetic anisotropy energy (MAE) of the system, triggering a sharp transition between the in-/off-plane configurations in multilayer F5GT.

To assess the seismic failure risk of post electrical equipment, an assessment method considering different sorts of uncertainty of the post electrical equipment was proposed. The aleatory and epistemic uncertainties were considered in the assessment, and the parameters in seismic hazard function of different sites were fitted. To investigate the effects of the supporting structure on the seismic fragility and risk of post electrical equipment, case studies on ultra-high-voltage gas insulated switchgear bushings mounted on two different supporting frames were conducted. The results indicated that both the maximum tensile stress of the bushing and the maximum displacement of the supporting frames should be considered as the limit statuses of the post electrical equipment. The different sorts of uncertainty increase the seismic failure risk of the post electrical equipment, and should be considered in the assessment. Besides, for the pillar-type porcelain element equipment, the supporting frames with lower lateral stiffness generated higher seismic failure risk. In constrast to the case of retrofitting the supporting frame to increase the lateral stiffness, the annual seismic failure risk of the GIS bushing mounted on the retrofitted supporting frame decreased 101%. Besides, the seismic failure risk of the post electrical equipment is not positive correlated with the peak ground acceleration. In the performance-based seismic design of the electrical substation, the seismic failure risk of the electrical equipment should be considered.

Synthetic red fluorescent protein (RFP) chromophores have emerged as valuable tools for biological imaging and therapeutic applications, but their application in the visualization of endogenous RNA G-quadruplexes (G4s) in living cells has been rarely reported so far. Here, by integrating the group of the excellent G4 dye ThT, we modulate RFP chromophores to create a novel fluorescent probe DEBIT with red emission. DEBIT selectively recognizes the G4 structure with the advantage of strong binding affinity, high selectivity, and excellent photostability. Using DEBIT as a fluorescent indicator, the real-time monitoring of RNA G4 in biological systems can be achieved. In summary, our work expands the application of synthetic RFP chromophores and provides an essential dye category to the classical G4 probes.

Copper (Cu), a promising catalyst for electrochemical CO2reduction (CO2R) to multi-electron reduction products, suffers from an unavoidable and uncontrollable reconstruction process during the reaction, which not only may lead to catalyst deactivation but also brings great challenges to the exploration of the structure–performance relationship. Herein, we present an efficient strategy for stabilizing Cu with silica and synthesize reconstruction-resistant CuSiOxamorphous nanotube catalysts with abundant atomic Cu–O–Si interfacial sites. The strong interfacial interaction between Cu and silica makes the Cu–O–Si interfacial sites ultrastable in the CO2R reaction without any apparent reconstruction, thus exhibiting high CO2-to-CH4selectivity (72.5%) and stability (FECH4remains above 60% after 12 h of test). A remarkable CO2-to-CH4conversion rate of 0.22 μmol cm–2s–1was also achieved in a flow cell device. This work provides a very promising route for the design of highly active and stable Cu-based CO2R catalysts.

ABSTRACTObjectivesParkinson’s disease (PD) is the second most common neurodegenerative disease. Chlorogenic acid (CGA) is a polyphenolic substance derived from various medicinal plants. Although CGA is reported to have potential anti-PD effect, the beneficial effect and the underlying mechanism remain unclear. In this study, we aimed to further investigate the protective effect and clarify the mechanism of action of CGA in Caenorhabditis elegans (C. elegans) models of PD.MethodsMeasurements of a-synuclein aggregation, movement disorders, and lipid, ROS and malondialdehyde (MDA) contents were observed in NL5901 nematodes. Determinations of dopamine (DA) neuron degeneration, food perception, and ROS content were performed in 6-OHDA-exposed BZ555 nematodes. The autophagy activation of CGA was monitored using DA2123 and BC12921 nematodes. Meanwhile, RNAi technology was employed to knockdown the autophagy-related genes and investigate whether the anti-PD effect of CGA was associated with autophagy induction in C. elegans.ResultsCGA significantly reduced α-synuclein aggregation, improved motor disorders, restored lipid content, and decreased ROS and MDA contents in NL5901 nematodes. Meanwhile, CGA inhibited DA neuron-degeneration and improved food-sensing behavior in 6-OHDA-exposed BZ555 nematodes. In addition, CGA increased the number of GFP::LGG-1 foci in DA2123 nematodes and degraded p62 protein in BC12921 nematodes. Meanwhile, CGA up-regulated the expression of autophagy-related genes in NL5901 nematodes. Moreover, the anti-PD effect of CGA was closely related to autophagy induction via increasing the expression of autophagy-related genes, including unc-51, bec-1, vps-34, and lgg-1.ConclusionsThe present study indicates that CGA exerts neuroprotective effect in C. elegansvia autophagy induction.

Lightning attachment characteristic of wind turbines have been investigated by experiments with two adjacent 1:100 reduced-scale wind turbine models, simulating two 2-MW wind turbines with blades equipped with two pairs of lightning receptors. Factors including directions of downward lightning leaders relative to the two wind turbine models, and blade rotation angles, were considered. Obtained results show that receptors, especially the blade-tip receptors, have excellent protection effect on the lightning leaders from higher altitudes or from the side of wind turbines, whereas they show weaker protection effect for those from lower altitudes or from the front of wind turbines. Moreover, blade rotation angles of two wind turbines have a certain impact on lightning attachment rates, showing a tendency that the protection effect of wind turbines can be improved with the increase of relative angle difference, the elevation angle difference of uppermost blade of two adjacent wind turbines. The underlying mechanism of this tendency is also discussed. Our experimental results show significance for improving the overall lightning protection capability of multiple wind turbines in wind farms.

Modification of the surface of raw activated carbon using chemical solvents can significantly improve the adsorption performance of activated carbon. Triethylenetetramine is one of the most important chemical solvents used to modify raw activated carbon for formaldehyde removal indoor. We conducted the liquid impregnation experiments at different initial concentrations, temperatures, adsorbent dosage and time ranges to fully investigate the adsorption of triethylenetetramine on the surface of raw activated carbon for modification. We found that the Langmuir isotherm model and pseudo-first-order kinetic model fit quite well with the experimental data and the R2are 0.9883 and 0.9954, respectively. The theoretical maximum adsorption capacity is 166.67 mg/g. The change in Gibbs free energy (ΔG0), enthalpy change (ΔH0) and entropy change (ΔS0) were also calculated to study the direction and driving force of the liquid adsorption process. In order to understand the adsorption process at the molecular level, a new activated carbon model based on the actual physical and chemical properties of activated carbon was carefully established in the Materials Studio to simulate the liquid-phase adsorption. The pore structure, elemental composition, functional group content, density, pore volume, and porosity of the activated carbon model converge close to the actual activated carbon and the adsorption isotherms obtained from the simulation agree well with the experimental results. The results show that the adsorption of triethylenetetramine on activated carbon is a spontaneous, endothermic and monolayer physical adsorption process.

The unique composition and condition of sludge pose significant challenges in water removal. Therefore, it is crucial to investigate a cost-effective and highly efficient approach for dehydrating sludge. In this paper, the domestic sludge was respectively pretreated with ferric chloride, polyaluminum chloride, and cationic polyacrylamide. Then the pretreated sludge was performed on gravity dehydration, centrifugal dehydration, dialysis dehydration and mixed method. The effect mechanism of coagulant and dewatering method on sludge dehydration was analyzed from micro perspective. Finally, the influence range of the dialytic solution was tested by model experiment. The results indicate that the dehydration efficiency of the pretreated sludge with PAC is slightly better than that pretreated with FeCl3and CPAM, and the optimal dosage of PAC is 8 %. The effect of dialysis dehydration is the best, which can significantly change the final moisture content of sludge (much less than 60 %), effectively achieving the requirements of subsequent processing. The water content of the sludge treated by gravity dehydration, centrifugal dehydration and dialysis dehydration can reach 38 %, which is much smaller than that of the sludge treated by a single dehydration method. The free water, occlusion, coating water, and bounding water are dehydrated by gravity, centrifugal force, and dialysis. The influence range of dialysis dehydration is less than 10 cm. When the distance is more than 10 cm, the difference of sludge moisture content at different relative heights is larger. The study has certain theoretical guidance significance for improving the performance of sludge concentration and dewatering.