Jun Zhou,Ximing Rong,Maxim S. Molokeev,Xiuwen Zhang,Zhiguo Xia
The electronic and optical properties of perovskites are related to the local structures of the compounds and define their functional applications. Herein we have prepared a double perovskite Cs2AgSbCl6, which crystallized in the cubic structure with the space group Fm-3m and the material is found to have a varied band gap associated with different body colors. The anti-site defect model was established to investigate transposition influence on the optical and electronic properties of the double-perovskite Cs2AgSbCl6, and the proposed model clearly explained the as-observed variable body color. Cs2AgSbCl6 perovskite has a high decomposition temperature and is stable upon prolonged exposure to air and moisture, which emphasize its potential in the field of photovoltaic absorbers and optoelectronic applications.
Yi-Xuan Liu,Hao-Cheng Thong,Chunlin Zhao,Qing Liu,Xingyu Xu,Ke Wang,Jing-Feng Li
The understanding of certain basic issues in (K,Na)NbO3 (KNN)-based systems is still missing, one of which being the influence of ZrO2 addition on the behaviors of KNN-based solid solutions at trace levels possibly introduced during the process of material preparation. Herein, KNN solid solutions with trace ZrO2 addition (0, 0.01, 0.05, and 0.1 mol%) were prepared by a normal sintering method. The dielectric permittivity and the piezoelectric coefficient d33 reach the maximum (εr = 497 and d33 = 139 pC N−1) with 0.1 mol% ZrO2 addition. Moreover, the microscopic results supported by PFM are in agreement with those from the macroscopic perspective. To establish the relationship among the ZrO2 addition contents, the induced defects and the properties of the solid solutions, a related defect model is proposed to support the experimental observation and the origin of induced defects is discussed. The results demonstrate that the properties of the KNN solid solutions can be closely affected by trace zirconia addition.
Chengyu Yang,Yang Liu,Ziyan Wang,Minmin Lin,Chao Liu
Despite the best treatment, approximately 10% of fractures still face undesirable repair and result in delayed unions or non-unions. Dynamic mechanical stimulation promotes bone formation, when applied at the correct time frame, with optimal loading magnitude, frequency, and repetition. Controlled mechanical loading significantly increases osteogenic cells during the matrix deposition phase of bone repair. In the bone defect, the blood vessel network guides the initial bone formation activities. A unique blood vessel subtype (Type H) exists in bone, which expresses high levels of CD31 and endomucin, and functions to couple angiogenesis and osteogenesis. However, how this form of controlled mechanical loading regulates the Type H vessels and promotes bone formation is still not clear. Sphingosine 1-phosphate (S1P) participates in the bone anabolic process and is a key regulator of the blood vessel. Its receptor, sphingosine 1-phosphate receptor 1 (S1Pr1), is a mechanosensitive protein that regulates vascular integrity. Therefore, we hypothesis that controlled anabolic mechanical loading promotes bone repair by acting on Type H vessels. To study the effect of S1Pr1 on loading induced-bone repair, we utilized a stabilized tibial defect model, which allows for the application of anabolic mechanical loading. Mechanical loading upregulated S1Pr1 within the entire defect, with up to 80% expressed in blood vessels, as observed by deep tissue imaging. Additionally, S1Pr1 antagonism by W146 inhibited the anabolic effects of mechanical loading. We showed that mechanical loading or activating S1Pr1 could induce YAP nuclear translocation, a key regulator in the cell's mechanical response, in endothelial cells (ECs) in vitro. Inhibition of S1Pr1 in endothelial cells by siRNA reduced loading-induced YAP nuclear translocation and expressions of angiogenic genes. In vivo, YAP nuclear translocation in Type H vessels was up-regulated after mechanical loading but was inhibited by antagonizing S1Pr1. S1Pr1 agonist, FTY720, increased bone volume and Type H vessel volume, similar to that of mechanical stimulation. In conclusion, controlled anabolic mechanical loading enhanced bone formation mainly through Type H vessels in a S1Pr1-dependent manner.
危险品化学品经营许可证（带存储）