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Much research and practical experience have shown that the utilization of textures has an enhancing effect on the performance of dynamic seals and the dynamic pressure lubrication of gas bearings. In order to optimize the performance of floating ring seals, this study systematically analyzes the effects of different texture shapes and their parameters. The Reynolds equation of the gas is solved by the successive over-relaxation (SOR) iteration method. The pressure and thickness distributions of the seal gas film are solved to derive the floating force, end leakage, friction, and the ratio of buoyancy to leakage within the seal. The effects of various texture shapes, including square, 2:1 rectangle, triangle, hexagon, and circle, as well as their parameters, such as texture depth, angle, and area share, on the sealing performance are discussed. Results show that the texture can increase the air film buoyancy and reduce friction, but it also increases the leakage by a small amount. Square textures and rectangular textures are relatively effective. The deeper the depth of the texture within a certain range, the better the overall performance of the floating ring seal. As the texture area percentage increases, leakage tends to increase and friction tends to decrease. A fractal roughness model is developed, the effect of surface roughness on sealing performance is briefly discussed, and finally the effect of surface texture with roughness is analyzed. Some texture parameters that can significantly optimize the sealing performance are obtained. Rectangular textures with certain parameters enhance the buoyancy of the air film by 81.2%, which is the most significant enhancement effect. This rectangular texture reduces friction by 25.8% but increases leakage by 79.5%. The triangular textures increase buoyancy by 28.02% and leakage increases by only 10.08% when the rotation speed is 15,000 r/min. The results show that texture with appropriate roughness significantly optimizes the performance of the floating ring seal. [ABSTRACT FROM AUTHOR]

High-performance Al2O3/graphite-Al2O3 laminated composites exhibit an excellent self-lubricating ability for moving components, such as sliding shaft sleeves and dynamic seals. The tribological behaviors of Al2O3/graphite-Al2O3 laminated composites should be studied extensively under water working conditions. Here, we attempted to explore the practicability of the Al2O3/graphite-Al2O3 laminated composite as a sealing material from a tribological point of view under water lubrication conditions. The tribological properties and mechanism of friction and wear of laminated composite ceramics were investigated under dry sliding friction, water environment, and suspended particle working conditions. It was found that the Al2O3/graphite-Al2O3 laminated composite has a better friction performance under water lubrication compared to dry sliding because of the separation effects formed by a water molecule film and a transfer film. Meanwhile, the wear rate under dry contact was found to be approximately six times that under water lubrication conditions. Under the water lubrication conditions, the formation of graphite films and water-adsorbed layers improved the anti-wear properties of the laminated materials, and the friction coefficient and the wear rate were as low as 0.16 and 1.76 × 10−6 mm3/Nm, respectively. Under the suspended particle working condition, the solid particles destroyed the graphite lubricating film and abrasive wear dominated the wear mode. The Al2O3/graphite-Al2O3 laminated composite demonstrates a potential for application in dynamic sealing and sliding components. [ABSTRACT FROM AUTHOR]

Phenylalanine ammonia-lyase is one of the most widely studied enzymes in the plant kingdom. It is a crucial pathway from primary metabolism to significant secondary phenylpropanoid metabolism in plants, and plays an essential role in plant growth, development, and stress defense. Although PAL has been studied in many actual plants, only one report has been reported on potato, one of the five primary staple foods in the world. In this study, 14 StPAL genes were identified in potato for the first time using a genome-wide bioinformatics analysis, and the expression patterns of these genes were further investigated using qRT-PCR. The results showed that the expressions of StPAL1, StPAL6, StPAL8, StPAL12, and StPAL13 were significantly up-regulated under drought and high temperature stress, indicating that they may be involved in the stress defense of potato against high temperature and drought. The expressions of StPAL1, StPAL2, and StPAL6 were significantly up-regulated after MeJa hormone treatment, indicating that these genes are involved in potato chemical defense mechanisms. These three stresses significantly inhibited the expression of StPAL7, StPAL10, and StPAL11, again proving that PAL is a multifunctional gene family, which may give plants resistance to multiple and different stresses. In the future, people may improve critical agronomic traits of crops by introducing other PAL genes. This study aims to deepen the understanding of the versatility of the PAL gene family and provide a valuable reference for further genetic improvement of the potato. [ABSTRACT FROM AUTHOR]

For the different degrees of danger caused by different driving habits, a lane departure warning algorithm based on probability statistics of driving habits is proposed in this paper. According to the different driving habits of different drivers, the early warning mechanism can be adaptively adjusted through the method of probability statistics to make lane departure warning more targeted and accurate. Firstly, each frame of image is preprocessed, including gray treatment, edge detection and binarization. Then, Canny operator is used to detect the edge, and Hough transform is applied to detect the lines. And the lane median line equation for the detection and identification of lane also can be calculated. After that, the image coordinate system is transformed into the world coordinate system by means of the formula and matrix of coordinate conversion. According to the theory of Kalman filter, the statistics of lateral acceleration and lateral velocity are updated continuously, and the position of the vehicle in the next moment is predicted by the state transition equation and the forecast equation. From the results of experiments and the comparison with exhaustive algorithms, the advantages of using Kalman filter to predict the location of vehicles and the improved time-to-lane-crossing combined with probabilistic statistics to warning are illustrated clearly. [ABSTRACT FROM AUTHOR]

In this study, the frictional properties of dry gas seal rings with a diamond-like carbon (DLC) film textured surface were investigated using a vertical universal friction and wear tester. The ensemble empirical mode decomposition (EEMD) method was applied to extract friction and vibration signals. In combination with chaos theory, analyses of the friction and wear of dry gas seal rings were performed under specific working conditions. The results show that the variation in friction vibration attractors and phase-point average distance is consistent with the change in the friction coefficient. The DLC film textured surface effectively improves the frictional properties of dry gas seals. The edges of the microtextured pits can cut debris, so the diameter of the debris becomes increasingly smaller. At the same time, the microtextured pits can also capture wear debris. The optimized dimple diameter and area density were 250 μm and 15%, respectively. In this case, the texture pit can catch almost all of the debris, but the friction vibration was not severe. [ABSTRACT FROM AUTHOR]