Abstract Using UPLC and PDA detector, the fingerprints of Dendrobium devonianum and Dendrobium officinale produced in the Longling area of Yunnan Province, China were obtained quickly and efficiently, and 26 common peaks in Dendrobium devonianum and Dendrobium officinale samples were obtained by automatic peak matching through the “Chinese Medicine Chromatographic Fingerprint Similarity Evaluation System”. The relative peak areas of the common peaks were analyzed by PCA using R, and the results showed that Dendrobium devonianum and Dendrobium officinale could be well distinguished by PCA, which was consistent with the analysis results of OPLS-DA. The results fully demonstrate that Dendrobium devonianum and Dendrobium officinale grown in the same area can be effectively distinguished by using the method of common peaks combined with stoichiometry. The VIP value of the 13 common peaks is greater than 1.0, which has a significant contribution to the difference and it was differential marker in Dendrobium devonianum and Dendrobium officinale. At the same time, normal-phase silica gel column chromatography was used to separate and purify the compounds that are related to the common peaks, and a total of 7 compounds were identified, among which eupatolide and isoschaftoside belong to differential markers and characteristic compounds in Dendrobium devonianum and Dendrobium officinale, which have good biological health care activity. The successful identification of Dendrobium devonianum and Dendrobium officinale in Longling area of Yunnan Province and the discovery of related differential markers play an important role in the further research and development of Dendrobium devonianum as a new food raw material and its products.

The effects of shot peening treatments on the microstructure and fatigue behavior of the teeth root in wet copper-based powder metallurgy friction plates were investigated and an efficient method for selecting optimal shot peening parameters for friction plates was proposed. Different experimental processes including microscopy observation, microhardness, roughness and X-ray diffraction measurements have been performed to characterize the treated surface of specimens. It is found that fatigue life of friction plates firstly increases and then decreases with the increase of Almen intensity, and the optimal fatigue life has improved over 55%. It is considered that both surface grain refinement and high residual compressive stress are the main ingredients responsible for the improved fatigue life. With further increase of Almen intensity, surface roughness of the teeth root gradually increases to a critical point, where rough peened surface may induce crack initiation due to stress concentration, and finally lead fatigue deteriorate.

In this work, the effect of C4+ and Cl4+ ion irradiation with 25 MeV energy on the hardness and shear banding feature of Ti40Zr25Be30Cr5 bulk metallic glass was studied. Depth-sensing nanoindetation and microindentation were applied for characterizing the multiple-scaled hardness and shear band patterns during plastic deformation. It is shown that the Cl4+ ion irradiation leads to an obvious softening of the sample surface, and distinctly affects the serrated flow feature during plastic deformation. In contrast, C4+ ions have little effect on the hardness and shear band patterns. Besides, the mechanism for the change of the mechanical properties and plastic deformation behavior after ion irradiation was also discussed.