[Market survey of Caryophylli Flos specifications].

The present study aimed to regulate the market circulation of Caryophylli Flos and formulate standards for commodity specifications and grades of Caryophylli Flos. Market survey was carried out in four major medicinal material markets with 48 samples of Caryophylli Flos collected. The property, 100-seed weight, impurity percentage, moisture, and eugenol content in Caryophylli Flos of different specifications from different producing areas were determined and analyzed. The results showed that 27.1% of the samples surveyed on the markets did not meet the requirements of Chinese Pharmacopoeia(2020 edition). The 100-seed weight and the property are important factors for the classification of Caryophylli Flos specifications. There were significant differences in the property, 100-seed weight, impurity percentage, and eugenol content in Caryophylli Flos samples of different specifications from different producing areas, and also differences in the proportions of different specifications in Caryophylli Flos samples from different producing areas. The African-originated Xiaohong(medium grade) and Guangxi-originated Xiaohong(medium grade) accounted for 70% and 66.7% respectively, the Indonesian-originated Dahong(top grade) for 56.2%. In conclusion, there are many problems in the circulation of Caryophylli Flos at present, mainly including the loss of origin information, no standards for specifications, non-implementation of grade standards, excessive impurities, and no evidence for authenticity identification. According to the classification of Caryophylli Flos specifications in this study, the average eugenol content of Xiaohong is significantly higher than the Dahong by 4.74%.

Molecular dynamics simulation of LiTFSI-acetamide electrolytes: structural properties.

The liquid structures of nonaqueous electrolytes composed of lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and acetamide, with LiTFSI/acetamide molar ratios of 1:2, 1:4, and 1:6, were studied by molecular dynamics simulations. The simulations indicate that the Li+ cations prefer to be six-coordinate by the sulfonyl oxygen atoms of the TFSI- anions and the carbonyl oxygen atoms of the acetamide molecules, rather than by the most electronegative nitrogen atom of the TFSI- anion. Therefore, close Li+-TFSI- contact pairs exist in the system. The TFSI- anion prefers to provide only one of four possible oxygen atoms to coordinate to the same Li+ cation. Three conformations (cis, trans, and gauche) of the TFSI- anions were found to coexist in the liquid electrolyte. At high salt concentrations, the TFSI- anions mainly adopt the gauche conformation in order to provide more oxygen atoms to coordinate to different Li+ cations, while simultaneously reducing the repulsion among the Li+ cations. On the other hand, the fraction of TFSI- anions adopting the cis conformation is largest for the system with the molar ratio of 1:6, in which many clusters, mainly composed of the Li+ cations and the TFSI- anions, are immersed in the acetamide molecules. The size and charge distribution of clusters were also investigated. In the system with the molar ratio of 1:2, nearly all of the ions in the PBC (periodic boundary conditions) box aggregate into a bulky cluster that gradually disassembles into small clusters with decreasing salt concentration. The addition of acetamide molecules was found to effectively relax the liquid electrolyte structure, and the system with the molar ratio of 1:4 was found to exhibit a more homogeneous liquid structure than the other two electrolyte systems with molar ratios of 1:2 and 1:6.