Strong [O III] {\lambda}5007 Compact Galaxies Identified from SDSS DR16 and Their Scaling Relations

Green pea galaxies are a special class of star-forming compact galaxies with strong [O III]{\lambda}5007 and considered as analogs of high-redshift Ly{\alpha}-emitting galaxies and potential sources for cosmic reionization. In this paper, we identify 76 strong [O III]{\lambda}5007 compact galaxies at z < 0.35 from DR1613 of the Sloan Digital Sky Survey. These galaxies present relatively low stellar mass, high star formation rate, and low metallicity. Both star-forming main sequence relation (SFMS) and mass-metallicity relation (MZR) are investigated and compared with green pea and blueberry galaxies collected from literature. It is found that our strong [O III] {\lambda}5007 compact galaxies share common properties with those compact galaxies with extreme star formation and show distinct scaling relations in respect to those of normal star-forming galaxies at the same redshift. The slope of SFMS is higher, indicates that strong [O III]{\lambda}5007 compact galaxies might grow faster in stellar mass. The lower MZR implies that they may be less chemically evolved and hence on the early stage of star formation. A further environmental investigation confirms that they inhabit relatively low-density regions. Future largescale spectroscopic surveys will provide more details on their physical origin and evolution.Comment: 12 pages, 8 figures, 1 table. Published in A

LRP6 Knockdown Ameliorates Insulin Resistance via Modulation of Autophagy by Regulating GSK3β Signaling in Human LO2 Hepatocytes

Recent studies suggest that autophagy is highly involved in insulin resistance (IR). Inhibition of the PI3K/AKT/mTOR signaling pathway induces autophagy activation. Additionally, depletion of LRP6 has been shown to increase insulin sensitivity but its mechanism is still not clear. We hypothesized that LRP6 contributes to IR by regulating mTOR mediated autophagy through GSK3β in hepatocytes. LO2 hepatocytes were treated with palmitate (PA) and insulin to induced IR. Levels of LRP6 mRNA and protein expression were measured by real time-PCR and western blot analysis. LRP6 knock down was achieved by adenovirus mediated Si-LRP6 expression and its roles in IR, glucose, GSK3β, mTOR signaling, and autophagy were explored. Finally, GSK3β was overexpressed and its involvement in autophagy and IR was examined. We found that PA treatment led to a reduced glucose uptake and IR in hepatocytes, which was accompanied by an upregulation of LRP6 expression. Knocking down of LRP6 enhanced glucose uptake and insulin sensitivity in PA treated cells, probably through increasing GSK3b activity. Overexpression of GSK3b mimicked LRP6 reduction by enhancing autophagy and ameliorating IR. Our study revealed a significant molecular mechanism connecting LRP6 to insulin sensitivity through GSK3β-mTOR mediated autophagy

Effects of Dietary Soy Protein Concentrate on Growth Performance, Digestion, and Protein Metabolism of Juvenile Darkbarbel Catfish Pelteobagrus vachelli

A 10-week feeding trial in a recirculation rearing system was conducted to investigate the effects of dietary soy protein concentrate (SPC) levels on survival, growth, digestion, and protein metabolism of juvenile darkbarbel catfish Pelteobagrus vachelli. The results demonstrated that survival and whole-body composition were independent of dietary treatments. Feed intake (FI), specific growth rate (SGR), feed conversion ratio (FCR), apparent digestibility coefficients, digestive enzymes (pepsin and trypsin) activity and protein metabolism enzymes (alanine aminotransferases) decreased with increasing dietary SPC. The diet with 60% SPC was least cost effective. Results suggest that SPC could replace 60% or less fish meal protein without negatively influencing the growth of juvenile Pelteobagrus vachelli

Numerical Simulation of Impact Rockburst of Elliptical Caverns with Different Axial Ratios

Herein, a finite discrete element method was used to simulate the rockburst phenomenon of elliptical caverns with different axis ratios. Two situations were employed, namely when the disturbance direction is perpendicular and parallel to the ellipse. Based on the peak stress, maximum velocity, stress nephogram, and image fractal characteristics, the influence of axis ratio and direction of the disturbance on rockburst were analyzed. The results show that the samples with different axis ratios experienced the same process of quiet period, slab cracking period, and rockburst. The rockburst pit had V shape, and the failure modes of rockburst primarily included shear cracks, horizontal tension cracks, and vertical tension cracks. With the rise in axis ratio, the peak stress and maximum speed increased. Furthermore, the pressure area on the left and right sides of the sample cavern decreased when the disturbance direction was parallel to the short axis of the ellipse, while it increased for the sample with a disturbance direction perpendicular to the short axis. The fractal dimension value of the crack was gradually amplified with disturbance. The fractal dimension value of the sample whose disturbance direction was perpendicular to the minor axis of the ellipse was lower, and it was more difficult to damage

Prediction and Experimental Validation of Aviation Floating Involute Spline

Based on the research on the wear mechanism of floating involute spline coupling, combined with the traditional Archard wear equation, a wear prediction model of aviation floating involute spline coupling was established. The transient simulation of spline coupling with floating distances of 0 mm, 0.3 mm, and 0.6 mm was carried out using Abaqus, and the accuracy of the theoretical model was verified by analyzing the wear and failure parts of the spline coupling. The analysis results show that there is oxidation wear, adhesive wear, abrasive wear, and other wear forms on the tooth surface of the aviation floating involute spline coupling. Under the influence of the floating distance of the spline coupling, the calculation results are closer to the actual working situations. In addition, with increasing floating distance, the wear depth of the tooth surface increases significantly, and the wear depth becomes larger and larger along the floating end. The above study provides a theoretical basis for designing and maintaining aerospace involute spline couplings

Simulation and Verification of Involute Spline Tooth Surface Wear before and after Carburizing Based on Energy Dissipation Method

This work studies the tooth surface wear of floating involute spline couplings. Based on the energy dissipation method, this study takes the floating involute spline couplings as the research object, divides the whole wear cycle into three wear stages and analyzes its wear mechanism, and proposes a wear prediction model suitable for floating involute spline couplings. By using Abaqus, the simulation of the involute spline couplings before and after carburizing was carried out when the floating distance was 0 mm, 0.3 mm and 0.6 mm, respectively. The wear depth of each tooth was compared and analyzed, and the axial and radial distributions of the wear on the tooth surface of the involute spline couplings were explored. Finally, the floating involute spline couplings test bench was used to verify the spline wear before and after carburizing. The results show that with the increase in floating distance, the wear of the tooth surface also increases, and the upper edge of the tooth surface is seriously worn. Through the comparative analysis of the spline tooth surface wear before and after carburizing treatment, it can be seen that carburizing treatment can effectively reduce the wear degree of the spline couplings tooth surface and improve the service life of the spline couplings, but at a high floating distance, carburizing treatment has no significant effect on improving the performance of the tooth surface

Prediction and Experimental Validation of Aviation Floating Involute Spline

Based on the research on the wear mechanism of floating involute spline coupling, combined with the traditional Archard wear equation, a wear prediction model of aviation floating involute spline coupling was established. The transient simulation of spline coupling with floating distances of 0 mm, 0.3 mm, and 0.6 mm was carried out using Abaqus, and the accuracy of the theoretical model was verified by analyzing the wear and failure parts of the spline coupling. The analysis results show that there is oxidation wear, adhesive wear, abrasive wear, and other wear forms on the tooth surface of the aviation floating involute spline coupling. Under the influence of the floating distance of the spline coupling, the calculation results are closer to the actual working situations. In addition, with increasing floating distance, the wear depth of the tooth surface increases significantly, and the wear depth becomes larger and larger along the floating end. The above study provides a theoretical basis for designing and maintaining aerospace involute spline couplings