Explore the vast range of titles available.

Acidic oxygen evolution reaction is crucial for practical proton exchange membrane water splitting electrolysers, which have been hindered by the high catalytic overpotential and high loading of noble metal catalysts. Here we present a torsion-strained Ta0.1Tm0.1Ir0.8O2-δ nanocatalyst with numerous grain boundaries that exhibit a low overpotential of 198 mV at 10 mA cm−2 towards oxygen evolution reaction in 0.5 M H2SO4. Microstructural analyses, X-ray absorption spectroscopy and theoretical calculations reveal that the synergistic effects between grain boundaries that result in torsion-strained Ir–O bonds and the doping induced ligand effect collectively tune the adsorption energy of oxygen intermediates, thus enhancing the catalytic activity. A proton exchange membrane electrolyser using a Ta0.1Tm0.1Ir0.8O2-δ nanocatalyst with a low mass loading of 0.2 mg cm−2 can operate stably at 1.5 A cm−2 for 500 hours with an estimated cost of US$1 per kilogram of H2, which is much lower than the target (US$2 per kg of H2) set by the US Department of Energy.Torsion-strained TaxTmyIr1−x−yO2−δ nanocatalyst with abundant grain boundaries is promising towards acidic oxygen evolution in practical proton exchange membrane electrolysers. The cost of H2 is estimated to be reduced to US$1 per kg.

The industrial applications of commercial pure titanium (CP-Ti) are significantly limited due to the strength-ductility trade-off in metallic materials. The strategy of heterostructured materials has been proposed to design microstructures for desired strength and ductility. To improve the mechanical properties of CP-Ti, a heterostructured rod, consisting of ultrafine fibrous grains and recrystallized grains, was produced by rotary swaging and subsequent annealing. The heterostructured Ti exhibits a high tensile strength of 636 MPa, simultaneously sustaining a high ductility of 11.9%, its tensile toughness is three times that of the swaged sample. The superior mechanical properties are attributed to the significant hetero-deformation induced (HDI) hardening in heterostructured Ti. It is found that the HDI hardening is induced by the interactions between geometrically necessary dislocations (GNDs) and hetero-interfaces.

With the continuous development and innovation of thermal management technology for lithium-ion batteries, the advantages of direct immersion liquid cooling technology have become increasingly prominent. However, at present, there is relatively little research on immersion liquid cooling systems, and current research is still mainly focused on small-capacity battery systems. Therefore, taking a large-capacity battery pack as the research object, a new type of single-phase immersion liquid cooling system was designed. The battery pack has a charge and discharge rate of 1C, consists of 52 cells, and has a total capacity of 52.249 kWh. It was compared with traditional liquid cooling and static immersion liquid cooling. Then, the effects of the aperture of the flow distributor, the inlet flow rate of the cooling liquid, and the type of cooling liquid on the cooling performance of the dynamic immersion battery pack were discussed. The holes on the flow distribution plate are primarily designed to facilitate a relatively uniform distribution of incoming liquid flow. Our research found that compared with traditional liquid cooling and static immersion liquid cooling, the overall cooling performance of the dynamic immersion cooling system was significantly improved, with the maximum temperature Tmax decreasing by 7.8 °C and 6.6 °C, the maximum temperature difference ΔTmax of the entire pack decreasing by 5.5 °C and 5.8 °C, and the maximum temperature difference U-DΔTmax between the top and bottom surfaces of the battery pack decreasing by 10.1 °C and 8.96 °C. An appropriate aperture had a positive impact on the cooling effect of the battery pack, with the best effect at a aperture of 4 mm. Tmax and ΔTmax gradually decreased with an increase in the flow rate of the cooling liquid, with Tmax decreasing from 42.3 °C to 31 °C and ΔTmax decreasing from 14.8 °C to 7.9 °C, but the rate of the temperature decrease gradually decreased. Deionized water in the cooling liquid had the best cooling effect, while ethyl silicone oil had the worst cooling effect. The novel single-phase immersion cooling system developed in this study serves as a valuable reference for the design of immersion liquid cooling systems in large-capacity battery packs, contributing to enhanced temperature uniformity and improved system safety.

This study develops an enhanced coding strategy with adaptive parameter adjustment mechanisms to address the premature convergence issue inherent in conventional genetic algorithms (GAs). An improved adaptive genetic algorithm (IAGA) is proposed for optimizing the slit pattern configurations of 16 steel-frame-slotted steel plate shear wall (SSPSW) systems. The methodology incorporates a real-time probability modulation of the crossover and mutation operations based on population diversity metrics. ABAQUS finite element software and PYTHON interactive analysis were systematically used to evaluate the mechanical performance of the optimized configurations, focusing on achieving an optimal ductility–stiffness balance under cyclic loading conditions. The numerical results demonstrate that the IAGA achieves faster convergence than standard GAs. A higher aspect ratio of the inter-slot column (l/b) or a smaller aspect ratio of the slot (b/t) leads to better ductility and lower stiffness. It is recommended that the configuration with connections on two sides of an SSPSW frame be adopted.

Anodic aluminum oxide (AAO) film with a thickness ranging from 20 to 100 μm was prepared using a large-sized Al plate (4 cm × 10 cm) to investigate the anodization parameter effect on the film thickness and volume expansion factor. A corrosion treatment (voltage = 0 V) was performed to investigate the film dissolution caused by acid. The actual anode surface temperature was also measured to confirm the field-assisted nature of AAO dissolution. The film thickness increases exponentially with temperature, and increases approximately linearly with voltage, duration or concentration. The volume expansion factor gives a first rising and then falling trend with temperature or duration, while it has a nearly linear trend with voltage or concentration. The volume expansion factor increases with the intensified electric field, while its decrease is attributed to the Joule heat-enhanced dissolution. In the case of large film thickness (> 20 μm), the pore confinement effect may be one of the reasons for the change of volume expansion factor. In addition to the conventional parameters, the heat transfer-related parameters (for example, sample size) also greatly affect the AAO film growth.

This study investigates the microstructures and deformation mechanism of hetero-structured pure Ti under different high strain rates (500 s−1, 1000 s−1, 2000 s−1). It has been observed that, in samples subjected to deformation, the changes in texture are minimal and the rise in temperature is relatively low. Therefore, the influence of these two factors on the deformation mechanism can be disregarded. As the strain rate increases, the dominance of dislocation slip decreases while deformation twinning becomes more prominent. Notably, at a strain rate of 2000 s−1, nanoscale twin lamellae are activated within the grain with a size of 500 nm, which is a rarely observed phenomenon in pure Ti. Additionally, martensitic phase transformation has also been identified. In order to establish a correlation between the stress required for twinning and the grain size, a modified Hall–Petch model is proposed, with the obtained value of Ktwin serving as an effective metric for this relationship. These findings greatly enhance our understanding of the mechanical responses of Ti and broaden the potential applications of Ti in dynamic deformation scenarios.

Background Tuberculosis (TB) remains a major global health threat. Mass screening effectively detects hidden TB cases and latent tuberculosis infections (LTBI), crucial for prevention. This study aims to use IFN-γ release assay (IGRA) screening in Deqing elderly reveals hidden TB and LTBI cases, explore the risk factors influencing the clustering of LTBI. Methods A cross-sectional study was conducted in 2023 among elderly residents (aged 60 years or above) in Deqing County using IGRA test (AIMTB). Participants were sampled from 13 towns or sub-districts proportional to their populations (26,234 participants, 19.01% of the elderly population aged 60 and above in Deqing). Demographic information and comorbidities were collected. Spatial autocorrelation analysis was conducted at the village level to identify LTBI clusters, and logistic regression was used to explore clustering risk factors by comparing population characteristics in hot spots versus cold spots. Results Of the 26,234 participants, 25,952 with complete data and definite IGRA results were included in the analysis. 1,878 were diagnosed with LTBI, resulting in an overall prevalence of 7.34%. LTBI prevalence was higher in males (8.69% vs. 6.01%, P  < 0.0001), those aged over 70 and 80 (8.80% vs. 7.24% vs. 6.66%, P  < 0.001), and individuals with low or high BMI (8.06% vs. 7.91% vs. 6.75%, P  < 0.0001), smokers (8.89% vs. 6.77%, P  < 0.001), and alcohol consumers (8.77% vs. 6.77%, P  < 0.0001). Spatial analysis revealed 18 villages as cold spots and 5 as hot spots. Multivariable logistic regression of cold and hot spots identified age (70–79) (OR = 1.550, 95% CI = 1.225–1.962, P  < 0.001) and alcohol consumers (OR = 1.495, 95% CI = 1.139–1.967, P  = 0.004) are clustering risk factors. BMI (< 18.5) (OR = 0.451, 95%CI = 0.319–0.637, P  < 0.001), and literate are clustering protective factors (OR = 0.556, 95%CI = 0.425–0.727, P  < 0.001). Conclusion This study underscores the high burden of LTBI among elderly males and individuals with certain risk factors in Deqing County. Identifying age and alcohol consumers as key factors in LTBI clustering suggests targeted interventions in high-risk villages could enhance TB prevention and control efforts.

The intelligent appearance quality classification method for Auricularia auricula is of great significance to promote this industry. This paper proposes an appearance quality classification method for Auricularia auricula based on the improved Faster Region-based Convolutional Neural Networks (improved Faster RCNN) framework. The original Faster RCNN is improved by establishing a multiscale feature fusion detection model to improve the accuracy and real-time performance of the model. The multiscale feature fusion detection model makes full use of shallow feature information to complete target detection. It fuses shallow features with rich detailed information with deep features rich in strong semantic information. Since the fusion algorithm directly uses the existing information of the feature extraction network, there is no additional calculation. The fused features contain more original detailed feature information. Therefore, the improved Faster RCNN can improve the final detection rate without sacrificing speed. By comparing with the original Faster RCNN model, the mean average precision (mAP) of the improved Faster RCNN is increased by 2.13%. The average precision (AP) of the first-level Auricularia auricula is almost unchanged at a high level. The AP of the second-level Auricularia auricula is increased by nearly 5%. And the third-level Auricularia auricula AP is increased by 1%. The improved Faster RCNN improves the frames per second from 6.81 of the original Faster RCNN to 13.5. Meanwhile, the influence of complex environment and image resolution on the Auricularia auricula detection is explored.

Effective processing and use of coal slime is of great significance to protect the environment and save resources. Different coal slimes (untreated with 43 wt% ash content, crushed and flotation treated with 10 wt% ash content, and pre-carbonized) were activated with KOH to prepare porous activated carbon. The results show the activated carbon prepared from coal slime with 10 wt% ash had high specific surface area (3037 m 2 /g) and pore volume (1.66 cm 3 /g), which was ascribed to the suitable contents of minerals as template and oxygen-containing functional groups. Electrochemical measurements exhibited the best specific capacitance of 220 F/g at 0.1 A/g and the cycle stability of over 100% capacitance retention after 1000 cycles at 5 A/g in 6 M KOH solution. Due to the high specific surface area, superior electrochemical performance, and facile and low cost, developing highly porous activated carbon for supercapacitors is one alternative way for effective use of coal slime waste.

Supercapacitors are considered among the most promising electrical energy storage devices, there being a need to achieve the highest possible energy storage density. Herein small mixed Zn–Co metal oxide nanoparticles are grown on doped graphene (O‐, N‐ and, B‐doped graphenes). The electrochemical properties of the resulting mixed Zn–Co metal oxide nanoparticles (4 nm) grown on B‐doped graphene exhibit an outstanding specific capacitance of 2568 F g−1 at 2 A g−1, ranking this B‐doped graphene composite among the best performing electrodes. The energy storage capacity is also remarkable even at large current densities (i.e., 640 F g−1 at 40 A g−1). In contrast, larger nanoparticles are obtained using N‐ and O‐doped graphenes as support, the resulting materials exhibiting lower performance. Besides energy storage, the Zn–Co oxide on B‐doped graphene shows notable electrochemical performance and stability obtaining a maximum energy density of 77.6 W h Kg−1 at 850 W Kg−1, a power density of 8500 W Kg−1 at 28.3 W h Kg−1, and a capacitance retention higher than 85% after 5000 cycles. The smaller nanoparticle size and improved electrochemical performance on B‐doped graphene‐based devices are attributed to the higher defect density and nature of the dopant element on graphene. Supercapacitors hold considerable promise over real energy needs in different applications such as wearable electronic devices and automotive, among others. Here, the structure–performance relationship of Zn and Co mixed metal oxide nanoparticles supported on different doped graphenes, is studied. The origin of the performance differences between the different doping elements on graphene is also investigated in detail.