The service life of rails would be remarkably reduced owing to the increase of axle load, which can induce the occurrence of damages such as cracks, collapse, fat edges, etc. Laser cladding, which can enhance the mechanical properties of the rail by creating a coating, has received great attention in the area of the rails due to the attractive advantages such as low input heat, small heat-affected zone, and small deformation. In this paper, recent developments in the microstructural characteristics and mechanical properties of a cladded layer on the rail are reviewed. The method of process optimization for enhancing the properties of a cladded layer are discussed. Finally, the trend of future development is forecasted.

The porous structure can effectively reduce the stress shielding effect in the process of implanting prostheses in the treatment of bone defects, but the performance of different types of porous structures directly affects the treatment effect, so it is necessary to evaluate a variety of different porous structures and select the most suitable structure type for implantation to improve the treatment effect. Based on the three-dimensional model of porous structure, this paper uses numerical analysis to evaluate the mechanical properties of porous structure and completes the primary selection of porous structure; secondly, the indexes and weights affecting the performance of porous structure are clarified, the calculation method of evaluation value is determined, and the evaluation system of implanted prosthesis with porous structure is constructed; then, through mechanical experiments and animal experiments, the machinability index and bone ingrowth index of the primary structure and commonly used clinical structure are studied; finally, according to the evaluation system, the most suitable type of porous structure for implantation is selected. The results of this study found that the tetrahedral body-centered structure [diamond structure] is the optimal structure type for the preparation of implanted prostheses with porous structures. The implantation of tetrahedral body-heart structure is of great significance for the treatment of segmental bone defects and can improve the quality of life of patients.

In this paper, in view of the stretcher transshipment transport stretcher part of car design modeling and simulation analysis, according to the design requirements for design transfer stretcher and with the back, legs Angle adjusting mechanism. AnyBody software is used to the human body back, leg movement simulation analysis, to select the reasonable of back, leg Angle adjusting range, provide the basis for transfer stretcher are comfortable design.