Theory, Method and Practice of Metal Deformation Instability: A Review.

Deformation instability is a macroscopic and microscopic phenomenon of non-uniformity and unstable deformation of materials under stress loading conditions, and it is affected by the intrinsic characteristics of materials, the structural geometry of materials, stress state and environmental conditions. Whether deformation instability is positive and constructive or negative and destructive, it objectively affects daily life at all times and the deformation instability based on metal-bearing analysis in engineering design has always been the focus of attention. Currently, the literature on deformation instability in review papers mainly focuses on the theoretical analysis of deformation instability (instability criteria). However, there are a limited number of papers that comprehensively classify and review the subject from the perspectives of material characteristic response, geometric structure response, analysis method and engineering application. Therefore, this paper aims to provide a comprehensive review of the existing literature on metal deformation instability, covering its fundamental principles, analytical methods, and engineering practices. The phenomenon and definition of deformation instability, the principle and viewpoint of deformation instability, the theoretical analysis, experimental research and simulation calculation of deformation instability, and the engineering application and prospect of deformation instability are described. This will provide a reference for metal bearing analysis and deformation instability design according to material deformation instability, structural deformation instability and localization conditions of deformation instability, etc. From the perspective of practical engineering applications, regarding the key problems in researching deformation instability, using reverse thinking to deduce and analyze the characteristics of deformation instability is the main trend of future research.

[Research progress on chemical composition and pharmacological effects of Periplocae Cortex and predictive analysis on Q-marker].

Periplocae Cortex is a traditional Chinese medicine in China, which is mainly produced in northeast China, north China, northwest China, southwest China. In recent years, the increasing in-depth research resulted in the discovery of anti-tumor and cardiac pharmacological activities of Periplocae Cortex, which has broad application prospects. On the basis of summarizing chemical components and pharmacological effects, combined with the theoretical system of Q-marker, the quality control components of Periplocae Cortex were predicted from the aspects of the correlation between chemical composition and traditional medicinal properties, traditional efficacy, and new clinical use, plasma composition, measurable composition, storage time by analyzing literature. Among the components, periplocoside, periplocin, periplogenin, 4-methoxy salicylaldehyde showed significant activity, which provides a scientific basis for quality evaluation of Periplocae Cortex.