Search

In order to improve the mechanical properties of the wear-resistant layer of the hob cutter ring in shield construction, the influence of different composite matrix powders on the comprehensive performance of the cladding layer was investigated. In this study, TiC-reinforced Fe-Ni-based cladding layers with different matrix compositions were prepared on a modified H13 steel base material using plasma cladding (PC) technology. The matrix powders included Ni-based alloy powder, iron powder Y, and iron powder R. The two iron powders were mixed in different proportions, and then an equal amount of Ni-based alloy powder and TiC ceramic particles were added to form five kinds of composite cladding layer alloy powders. The cladding layers of five different matrices were obtained by cladding. The microstructure and mechanical properties of the composite cladding layer were studied using a metallographic microscope (OM), an X-ray diffractometer (XRD), a scanning electron microscope (SEM), an energy dispersive spectrometer (EDS), an electronic universal testing machine, an image processing microhardness tester, and an abrasive belt friction and wear testing machine. The results showed that the cladding layers of different samples had good metallurgical bonding with the base material. And the microstructure gradually refined from the bottom of the cladding layer to the top of the cladding layer. The cladding layer phases were mainly composed of Fe, FeO, TiC, FeNi, and CrNi. With the increase in the iron powder R ratio, the aggregation of alloy elements gradually alleviated. The ratio of iron powder R was increased from 1/10 to 2/5, the longitudinal shear strength between the cladding layer and the matrix was increased from 318 Mpa to 333 Mpa, and the transverse shear strength was increased from 303 Mpa to 342 Mpa. The hardness of the modified wear-resistant layer was better than that of the cladding layer without iron powder R, but the hardness of the cladding layer gradually decreased. After the modification of iron powder R, the wear resistance of the cladding layer was improved to varying degrees. When Y:R was 9:1, its wear resistance was the best, and the change trend of the wear resistance was consistent with that of hardness. The wear forms of different samples were adhesive wear and abrasive wear. And the height difference of the wear surface gradually increased with the improvement in wear resistance. [ABSTRACT FROM AUTHOR]

In order to effectively solve the problems of the complex growth state of dragon fruit and how the picking process is mostly manual, this study designed a picking and selecting integrated remote-operation-type dragon-fruit-picking device. Based on SOLIDWORKS 2020 software for the three-dimensional digital design and overall assembly of key components, the structure and working theory of the machine are introduced. By improving the high-recognition-rate dragon fruit target detection algorithm based on YOLOv5, better recognition and locating effects were achieved for targets with a small size and high density, as well as those in bright-light scenes. Serial communication, information acquisition, and the precise control of each picking action were realized by building the software and hardware platforms of the picking device control system. By analyzing the working principle of the mechanical system and the mechanics of the machine picking process, the critical factors affecting the net picking rate and damage rate of the dragon-fruit-picking device were confirmed. Based on the force and parameter analysis of the test results, it was confirmed that the machine had an optimal picking influence when the flexible claw closing speed was 0.029 m/s, the electric cylinder extending speed was 0.085 m/s, and the mechanical arm moving speed was 0.15 m/s. The net picking rate of the device reached 90.5%, and the damage rate reached 2.9%. The picking device can complete the picking of a single dragon fruit, as well as a plurality of fruits grown at a growing point, and integrates the integration of picking fruits, removing bad fruits, and sorting fruits, which can improve the efficiency of dragon fruit harvesting and replace manual work. [ABSTRACT FROM AUTHOR]

Accurate and fast detection of traffic sign information is vital for autonomous driving systems. However, the YOLOv5 algorithm faces challenges with low accuracy and slow detection when it is used for traffic sign detection. To address these shortcomings, this paper introduces an accurate and fast traffic sign detection algorithm–YOLOv5-Efficient Vision TransFormer(EfficientViT)). The algorithm focuses on improving both the accuracy and speed of the model by replacing the CSPDarknet backbone of the YOLOv5(s) model with the EfficientViT network. Additionally, the algorithm incorporates the Convolutional Block Attention Module(CBAM) attention mechanism to enhance feature layer information extraction and boost the accuracy of the detection algorithm. To mitigate the adverse effects of low-quality labels on gradient generation and enhance the competitiveness of high-quality anchor frames, a superior gradient gain allocation strategy is employed. Furthermore, the strategy introduces the Wise-IoU (WIoU), a dynamic non-monotonic focusing mechanism for bounding box loss, to further enhance the accuracy and speed of the object detection algorithm. The algorithm's effectiveness is validated through experiments conducted on the 3L-TT100K traffic sign dataset, showcasing a mean average precision (mAP) of 94.1% in traffic sign detection. This mAP surpasses the performance of the YOLOv5(s) algorithm by 4.76% and outperforms the baseline algorithm. Additionally, the algorithm achieves a detection speed of 62.50 frames per second, which is much better than the baseline algorithm. [ABSTRACT FROM AUTHOR]

This paper develops a coupling model of the relationship between chemical reaction, temperature and stress/strain for Li (Ni0.6Mn0.2Co0.2) O2 cathode materials. With the process of reaction, the concentration of electrolyte salt changes rapidly at the beginning of diffusion and tends to dynamic equilibrium. The concentration of electrolyte LiPF6 in electrode materials diffuses from bottom to top with the process of lithium intercalation. In the process of Li-ion intercalation, the temperature rise of porous electrode materials increases sharply at first, then decreases and then increases slowly. The rate of temperature rise in the cathode material increases with the temperature decreases. The volume of electrode material deformed with the expansion along the X-axis and the radial bending along the Y-axis. And the law of stress variation with time is consistent with the temperature-time curve. By the stress-strain distribution nephogram, it is found that the position where the maximum stress is located at the edge of the upper surface, and which is most vulnerable to failure. [ABSTRACT FROM AUTHOR]

The ability and capacity of silicon and carbon nanocages (C38, F-C38, Cl-C38, Si38, F-Si38, Cl-Si38) as anodes of batteries are investigated to suggest the new nano-compounds as basic material of electrodes of batteries with suitable performance. The electrochemical parameters of C and Si nanocages as anodes of batteries are examined and compared by using of the computational models. The halogen (F and Cl) atoms are linked to Si38 and C38 as anodes in batteries to improve their capacity by theoretical models. The interaction energies of nanostructures with F and Cl atoms, interaction energies of nanostructures with Li and Mg and interaction energies of F-nanostructures and Cl-nanostructures with Li+ and Mg+2 ions are calculated by theoretical models. Finally, the F-Si38 and Cl-Si38 nanocages are suggested as suitable effective nano structures to utilize as electrodes in batteries. [ABSTRACT FROM AUTHOR]

Diallyl trisulfide (DATS), a major garlic derivative, inhibits cell proliferation and triggers apoptosis in a variety of cancer cell lines. However, the effects of DATS on hepatic stellate cells (HSCs) remain unknown. The aim of this study was to analyze the effects of DATS on cell proliferation and apoptosis, as well as the protein expression profile in rat HSCs. Rat HSCs were treated with or without 12 and 24 [micro]g/mL DATS for various time intervals. Cell proliferation and apoptosis were determined using tetrazolium dye (MTT) colorimetric assay, bromodeoxyuridine (5-bromo-2'-deoxyuridine; BrdU) assay, Hoechst 33342 staining, electroscopy, and flow cytometry. Protein expression patterns in HSCs were systematically studied using 2-dimensional electrophoresis and mass spectrometry. DATS inhibited cell proliferation and induced apoptosis of HSCs in a time-dependent manner. We observed clear morphological changes in apoptotic HSCs and dramatically increased annexin V-positive-propidium iodide negative apoptosis compared with the untreated control group. Twenty-one significant differentially expressed proteins, including 9 downregulated proteins and 12 upregulated proteins, were identified after DATS administration, and most of them were involved in apoptosis. Our results suggest that DATS is an inducer of apoptosis in HSCs, and several key proteins may be involved in the molecular mechanism of apoptosis induced by DATS. Key words: diallyl trisulfide, apoptosis, hepatic stellate cells, differentially expressed proteins. Le trisulfure de diallyle (TSDA), un derive important de l'ail, inhibe la proliferation cellulaire et declenche l'apoptose dans une variete de lignees cellulaires cancereuses. Cependant, les effets du TSDA sur les cellules de Kupffer (CK) restent inconnus. Cette etude visait; a analyser les effets du TSDA sur la proliferation cellulaire et l'apoptose, de meme que sur le profil d'expression des proteines dans les CK de rat. Les CK de rat ont ete traitees ou non avec 12 et 24 [micro]g/mL de TSDA pendant differentes periodes de temps. La proliferation cellulaire et l'apoptose ont ete determinees l'aide d'un dosage colorimetrique au tetrazolium (MTT), d'un dosage a la bromodeoxyuridine (5-bromo-2'-deoxyuridine, BrdU), par coloration au Hoechst 33342, par microscopie electronique et par cytometrie en flux. Les patrons d'expression proteique des CK ont ete systematiquement etudies par electrophorese en deux dimensions et par spectroscopie de masse. Le TSDA inhibait la proliferation cellulaire et induisait l'apoptose des CK en fonction du temps. Les auteurs ont observe des changements morphologiques clairs des CK en apoptose et une augmentation importante des cellules en apoptose positives l'annexine V et negatives l'iodure de propidium comparativement au groupe controle non traite. Vingt et une proteines exprimees de facon differentielle, soit neuf proteines regulees a la baisse et 12 proteines regulees a la hausse, ont ete identifiees a la suite de l'administration de TSDA, et la plupart d'entre elles etaient impliquees dans l'apoptose. Les resultats des auteurs suggerent que le TSDA est un inducteur de l'apoptose chez les CK et que plusieurs proteines cles peuvent etre impliquees dans le mecanisme moleculaire de l'apoptose induite par le TSDA. [Traduit par la Redaction] Mots-cles : trisulfure de diallyle, apoptose, cellules de Kupffer, proteines exprimees de facon differentielle., Introduction Liver fibrosis is a disease affecting an estimated 100 million people worldwide (Curry 2013; Morgan et al. 2013). Liver fibrosis and associated cirrhosis are caused by chronic viral hepatitis, [...]

Nickel-rich ternary cathode materials (NRTCMs) have high energy density and a long cycle life, making them one of the cathode materials of LIB that are currently receiving much attention. However, it has shortcomings such as poor cycling performance (CP) and a high-capacity decay rate. Because of this, the study analyzed the modification effect of WO3 on NRTCM lithium batteries by preparing WO3-modified poly-crystal and single-crystal NCM622 materials under the existing conditions of better original cathode materials as reference samples. The results showed that in the morphology and structure testing, with the increase of WO3 addition, the c/a values of all NCM622-WO3 samples were greater than 4.95. In the analysis of cycling and rate performance (CRP), as W increased, the rate performance (RP) of the NCM622-W4.0 sample had a discharge specific capacity ratio of 86.2% at 10.0 C/1.0 C. In cyclic voltammetry testing, when the addition amount of WO3 was 1.0%, the polarization degree of SC-NCM622 sample was the weakest. In the AC impedance test, after six cycles, compared with the original sample, the Ret and R + Rct values of the NCM622-W sample modified with WO3 showed a significant downward trend. The above results prove that WO3 modification can lower the polarization of the material, effectively raising the CRP of the battery. It provides a reference path for the further progress of high capacity and stability ternary cathode materials. [ABSTRACT FROM AUTHOR]

The phase structure of the precursor is crucial for the microstructure evolution and stability of Ni-rich cathode materials. Using sodium lactate as a green complexing agent, cathode electrode materials with different phase structures and unique core–shell structures were prepared by the co-precipitation method in this study. The influence of the phase structure of the nickel-rich precursor on the cathode electrode materials was studied in depth. It was found that α-NCM811 had large interlayer spacing, which was beneficial for the diffusion of lithium ions. In contrast, β-NCM811 had smaller interlayer spacing, a good layered structure, and lower ion mixing, resulting in better cycling performance. The core–shell-αβ-NCM811 with α-NCM811 as the core and β-NCM811 as the shell was prepared by combining the advantages of the two different phases. The core–shell-αβ-NCM811 showed the highest discharge capacity of 158.7 mAh/g at 5 C and delivered excellent rate performance. In addition, the β-NCM811 shell structure with smaller layer spacing could prevent corrosion of the α-NCM811 core by the electrolyte. Thus, the capacity retention rate of the core–shell-αβ-NCM811 was still as high as 86.16% after 100 cycles. [ABSTRACT FROM AUTHOR]