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A novel Fe-Cr-B-C-Al-Si-Mn composite coating was designed and synthesized on 2Cr13 steel substrate using laser cladding technique in this study. The microstructure evolution, microhardness and wear resistance of the composite coating were investigated. The results showed that the microstructure of the coating was mainly composed of α-(Fe,Cr,Al) martensite, retained γ-Fe, and the eutectic comprised of CrFeB, M3(C,B)2, M2(B,C) and M23(C,B)6. The average microhardness of the coating (742.1 HV0.5) was 3.95 times compared with the 2Cr13 steel substrate, and the wear resistance was enhanced by 12.5 times compared with the 2Cr13 steel substrate. The wear mechanisms were dominated by abrasive wear and oxidative wear.

Knowledge of the mechanical properties of human skin has essential applications in cosmetic, dermatology and surgical fields. In this study, a hybrid experimental–numerical method was developed to characterize the human skin mechanical properties in vivo. An indentation experiment was physically conducted and simulated by finite element (FE) analysis. In the physical experiment, an indenter made of transparent glass was adopted so that the elliptical eccentricity in the contact area between skin and indenter could be monitored in real-time. In FE simulation, the dermis and subcutaneous tissue were modeled as anisotropic hyperelastic material and isotropic elastic material, respectively. By fitting the FE results to the experimental data, the three-dimensional (3D) mechanical properties of skin, including the dermis and subcutaneous tissue were determined. Furthermore, to demonstrate the ineffectiveness of the hybrid experimental–numerical method, a sensitivity analysis was conducted. In this sensitivity analysis, it is shown that the different mechanical parameters have a different contribution to the final FE result. Finally, the effect of subcutaneous tissue for in vivo skin indentation measurement was also evaluated.

In vivo characterization of facial soft tissue is of great significance for facial plastic surgery, animation and dermatology. This paper presents an in vivo experimental method to characterize the macroscopic mechanical properties of facial soft tissue. In this method, a bi-layer material (BLM) model is established with the skeleton as the substrate under the facial soft tissue and the relationship between the mechanical properties of soft tissue and force–displacement curve is obtained. A novel indentation apparatus is also developed to experimentally measure the force-displacement curve of the facial soft tissue in vivo. Using the apparatus, experiments were conducted on artificial skins to verify the theoretical model. Experiments on facial soft tissue were finally conducted on four volunteers to obtain Young’s moduli at five facial locations using an optimal indenter whose radius is determined by the verification experiment. Our experiment results indicate that a slight difference is observed in Young’s moduli of facial soft tissue among different volunteers and indentation location. At locations of the left-hand cheek near the lips (NE) and center of the left-hand jaw (CJ), Young’s moduli [Formula: see text] are relatively large ranging from 2.653[Formula: see text]kPa to 4.437[Formula: see text]kPa. Nevertheless, at other locations of the center of the cheek (CC), left-hand zygomatic region (ZYG) and left-hand cheek near the lips (NL), the contact forces are smaller, and Young’s moduli [Formula: see text] are between 1.649[Formula: see text]kPa and 3.395[Formula: see text]kPa.

The solubility of cobalt oxide in silica-saturated iron silicate slags (1.16 to 10.00 wt pct) in equilibrium with cobalt-gold-iron alloys (1.10 to 6.52 wt pct cobalt) and oxygen pressures of 10−9 to 10−10 atm (1 atm = 1.013 x 105 Pa) has been investigated at 1573 K. The activity coefficient of cobalt oxide, γCoO, has been calculated relative to pure solid cobalt oxide as standard, namely, γCoO = 0.91 ± 0.09

Two-dimensional interaction between two Taylor vortices is simulated systematically through solving the two-dimensional, unsteady compressible Navier-Stokes equations using a fifth order weighted essentially nonoscillatory finite difference scheme. The main purpose of this study is to reveal the mechanism of sound generation in two-dimensional interaction of two Taylor vortices. Based on an extensive parameter study on the evolution of the vorticity field, we classify the interaction of two Taylor vortices into four types. The first type is the interaction of two counter-rotating vortices with similar strengths. The second type is the interaction of two co-rotating vortices without merging. The third type is the merging of two co-rotating vortices. The fourth type is the interaction of two vortices with a large difference in their strengths or scales. The mechanism of sound generation is analyzed.