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Abstract To improve the mechanical properties of the rolling body surface of wind power bearings, extend its service life. In this study, a large-scale molecular/atomic parallel processor LAMMPS was introduced, and then the process of magnetron sputtering technology in the preparation of DLC/Ni-DLC thin films on the 42CrMo substrate material was simulated. The effects of deposition parameters such as sputtering temperature, sputtering voltage, deposition air pressure, and Ni doping on the residual stress, film base bonding, and organizational structure of the thin films were investigated. The simulation results show that for different deposition parameters, the atomic tensile and compressive stresses existed simultaneously in DLC/Ni-DLC films, and the residual stresses were between − 0.504–5.003 Gpa and − 2.11–0.065 Gpa, respectively; the doping of Ni effectively improved the distribution of hybrid structure and the mechanical properties of the DLC films, and the ratio of the sp3 hybrid structure in the film organization was about 2.56 times higher than that of the non-doped films, and the membrane base bonding force was increased by 32.78% and the residual stress is reduced and transitioned from tensile stress to compressive stress. In addition, it was observed that the thickness of the mixed layer of DLC/Ni-DLC films with the substrate was not increased after the thickness of the mixed layer was extended to about 2 nm. Nickel doping and reasonable control of deposition parameters help to reduce the residual stress and improve the bonding strength of the film by changing the organizational structure of the film, which provides an important theoretical and scientific basis for the preparation of low-stress, high-performance and long-life DLC films and the wide application of rolling bodies for wind power bearings under complex working conditions.

The computing and storage resources of the industrial Internet of things (IIoT) equipment in the coal mine are limited, making it vulnerable to illegal network intrusion, causing sensitive data leakage or malicious tampering, and threatening the safety of coal mine production. Precise recognition of coal mine IIoT equipment can achieve effective management and maintenance of equipment operation, improve equipment safety and protection capabilities. However, existing equipment recognition algorithms suffer from complex feature construction, high memory and computing requirements, making it difficult to deploy in resource limited coal mine IIoT equipment. In order to solve the above problems, a coal mine IIoT equipment recognition model is proposed. Firstly, the model performs traffic segmentation, irrelevant field removal, deduplication, and fixed length field truncation operations on traffic data that supports TCP/IP protocol transmission. The model then converts it to IDX format for storage. Secondly, the model uses convolutional block attention module (CBAM) to optimize depthwise separable convolu-tion(DSC). A lightweight DSC-CBAM model is constructed to filter Non-IIoT equipment. Thirdly, the Wasserstein generative adversarial network with gradient penalty (WGAN-GP) is used to expand the data of coal mine IIoT equipment with less traffic, achieving the goal of balancing offset traffic data. Finally, multi-scale feature fusion (MFF) technology is introduced on the basis of DSC-CBAM to capture shallow global feature information, and Mish activation function is added to improve model training stability. The MFF-DSC-CBAM-Mish (MDCM) model is established to achieve precise recognition of coal mine IIoT equipment. The experimental results show that the model has a fast convergence speed, with accuracy, recall, precision, and F1 score all reaching 99.98%. The model has a small number of parameters, which can accurately and efficiently recognize IIoT equipment in coal mines.

In this study, glycerin was used instead of traditional solvents such as methanol in combination with ultrasonic treatment for the high-efficiency extraction of multiple chemical components from tea. Furthermore, a quantitative analytical method for 130 chemical components belonging to seven classes in tea and its by-products was developed using ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry (UPLC-QQQ-MS/MS). The results showed that the extraction efficiency of glycerol was comparable to that of methanol and ethanol, and significantly better than that of water. The developed method had high sensitivity (limit of detection of 0.000 1-4.332 1 mg/kg) and accuracy (recoveries of 80.10%–121.12%). Appling this method to real samples, the content of each component varied greatly among different types of tea and by-products. Compared with tea samples, tea residue, a tea by-product, contained higher contents of caffeine, catechin and theanine, indicating the potential value of this by-product.

Plant wax ester synthase catalyzes the synthesis of wax esters from long-chain alcohols and fatty acids, and plays very important roles in plant wax synthesis and some resistances to drought, pathogenic bacteria, ultraviolet radiation, cold and insect invasion and other environmental stresses; cadmium (Cd) is one of the toxic heavy metals with the highest content in environment, and seriously threatens plant growth, development, quality, yield, and plant food safety. In order to explore the Cd stress expressions of wax ester synthase genes in Rehmannia glutinosa, we identified its wax ester synthase genes from its full-length transcriptome sequencing data, analyzed both physiochemical properties, phytogenetic trees and conserved domains with bioinformatics methods, and tissue expressions and Cd stress expressions using qRT-PCR. The results were as follows: (1) Two wax ester synthase genes, named as RgOATWSD1 and RgOATWSD2, were identified, whose coding proteins were unstable hydrophobic proteins with amino acid lengths of 463 aa and 473 aa, isoelectric points of 8.86 and 9.34 and molecular weights of 51.31 kD and 52.49 kD, respectively. (2) Both proteins contained a conserved acyl_WS_DGAT domain and DUF1298 superfamily, in which the former accounted for 92.65% to 94.50% of the amino acid sequence. (3) Both proteins were located in the endoplasmic reticulum and both secondary structures were mainly composed of random coil and α-helix;RgOATWSD2 was not transmembrane protein but RgOATWSD1. (4) Both were differentially expressed in the roots, stems and leaves of R. glutinosa plants. (5) Both expressions were highly responsive to Cd stress, but both expression change trends were different under Cd stress. This study identifies two wax ester synthase genes in response to Cd stress, and lays a foundation for further research on Cd stress expression and other functions of RgOATWSD.