Jianning Liu,Dongyan Zhang,Yangxi Yan,Zhimin Li,Fei Li,Sen Yang
Acceptor doping is a common method for hardening modified piezoelectric ceramics. The mechanism through which the hardening effect can be improved has been widely studied and verified. However, the effect of defects caused by different valence states of the B-site ions on the properties of multicomponent piezoelectric ceramics remains to be discussed. Therefore, in this work, a novel Pb(Ni 1/3 Nb 2/3 )O 3 –Pb(In 1/2 Nb 1/2 )O 3 –Pb(Mn 1/3 Nb 1/2 )–PbTiO 3 quaternary hard ceramic with excellent performance is prepared and studied. The interaction between grain-boundary defects and defect dipoles is proposed to be the mechanism behind the observed excellent performance. It is found that different types of defects improve the hardening effect in various ways. These results can provide a theoretical basis for the preparation of multicomponent piezoelectric ceramics with better properties.
To investigate the hardening mechanisms of CrN-based hard coatings, transmission electron microscopy (TEM) was employed to correlate nanoindentation-induced deformation with microstructural evolution. Among the investigated coatings, CrAlN exhibits the highest hardness and Young's modulus (41.2 GPa/402.8 GPa), outperforming CrSiN (30.5 GPa/336.2 GPa) and CrN (26.7 GPa/305.7 GPa). The superior performance of the CrAlN is attributed to a coordinated deformation mechanism involving ∼9° deflection of columnar grains under compression loading, which facilitates stress redistribution while maintaining structural continuity. Additionally, stress-induced phase transformations at acute-angle grain boundaries—from FCC CrAlN to HCP Cr 2 N and FCC AlN—further enhance strain accommodation, contributing to an improved strength-toughness balance. In contrast, CrSiN coating develops internal crack formation accompanied by Cr 2 N phases. While these transformations increased hardness, they also introduced embrittlement, compromising ductility. The CrN coating, lacking both solid-solution strengthening and grain refinement, displayed extensive trans-granular fracture and grain disintegration, indicative of limited capacity for stress delocalization. These findings provide mechanistic insights into the structure–property relationships of CrN-based coatings and offer design guidelines for the development of advanced wear-resistant coatings with tailored mechanical responses.
Background: Atherosclerosis (AS) serves as the primary pathological foundation for numerous cardiovascular diseases, such as thromboembolic conditions, coronary artery disease, and ischemic cardiac-cerebral vascular disorders. Sanzi San, a traditional Chinese medicinal formulation with a long-standing clinical reputation for efficacy against AS, has not yet had its pharmacological mechanisms fully elucidated. Objective: Our objective is to investigate the impact of Sanzi San on AS in ApoE −/− mice models and elucidate the pharmacological mechanism via an integrated approach of serum pharmacochemistry, network pharmacology, and pharmacokinetic analysis. Materials and Methods: The chemical constituents in Sanzi San and serum were identified using high-performance liquid chromatography-quadrupole/Orbitrap high-resolution mass spectrometry (HPLC-Q/Orbitrap HRMS). A network pharmacology approach, including protein–protein interaction (PPI) and gene ontology enrichment analyses, was then used to investigate the connection between these components and their anti-atherosclerotic activity. Finally, ultra-HPLC-tandem mass spectrometry was used to determine the formula’s pharmacokinetic parameters following oral administration. Results: Through a comparison of serum samples from control and treated groups, 41 prototype compounds originating from Sanzi San were identified. These constituents were classified into three major groups – terpenes, iridoids, and phenolic acids – and were regarded as the potential bioactive components due to their absorption into the bloodstream. Network pharmacology analysis indicated that Sanzi San directly influences blood vessels by regulating their diameter to achieve therapeutic effects. Furthermore, Sanzi San demonstrated therapeutic potential by specifically targeting natural killer (NK) cells within plaque tissue and adventitial cells in the aorta. In vivo validation in ApoE −/− mice showed that Sanzi San improved aortic lesions and regulated body weight. Pharmacokinetic studies also revealed that seven major components of Sanzi San were present in plasma, confirming its pharmacological effects on AS. Conclusion: This study provides evidence of Sanzi San’s clinical efficacy in treating AS. The integrated strategy combining serum pharmacochemistry, network pharmacology, and pharmacokinetics offers a powerful approach for uncovering the key pharmacological mechanisms of herbal formulations.
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