Search

As a part of our systematic study on Castanopsis genus (Fagaceae), one new triterpene hydrolysable tannin (1) and two new phenol glucosides (2 and 3) were isolated from the leaves of Castanopsis eyrei (Champ. ex Benth.) Hutch. Compound 1 was identified as a triterpene hexahydroxydiphenoyl (HHDP) ester. This type of compounds has only been isolated from Castanopsis genus. The structures of 1-3 were elucidated by the combination of spectroscopic analysis (MS, 1 D and 2 D NMR) and chemical evidence. [ABSTRACT FROM AUTHOR]

To realize the high value–added utilization of acid-washed iron red, in this paper, acid-washed iron red is used as raw material. Aiming at the problem of low conductivity of iron-based lithium ion batteries (LIBs) LiFePO4/C materials, different metal ions are doped in the iron position, and the microstructure and electrochemical properties of the obtained material are systematically studied. Here, LiFePO4/C is synthesized through simple carbothermal reduction method using acid-washed iron red as the iron source. On this basis, La (1%, 2%, 3%) doping modification is carried out. Then doped modification is performed on this basis, preferably 2% La-doped LiFePO4/C materials. The XRD patterns show that the diffraction peaks of the samples prepared at all doping amounts can be perfectly matched with the standard card (PDF # 40–1499), and there is no impurity peak, all of which are pure phases. According to the refined data, it is clear that minor amount of La has successfully replaced the position of Fe and incorporated into the lattice. Electrochemical tests show that LiFe0.98La0.02PO4/C has the highest charge and discharge capacity of 146.5/138.2 mAh·g−1 in the first cycle at 0.5C, and the reversible specific capacity of 136.5 mAh·g−1 remains after 50 cycles. Furthermore, the first-principles calculations more strongly confirm that La doping can significantly improve the defects of low electronic conductivity of LiFePO4. [ABSTRACT FROM AUTHOR]

In order to better recycle and reuse metal ions in metallurgical industrial waste and reduce the production cost of lithium-ion batteries (LIBs). In this paper, carbon-coated LiFePO4/C cathode materials are synthesized through the carbothermal reduction method using acid-washed iron red as raw material. In order to make LiFePO4/C exhibit satisfactory electrical properties, the rare earth element Eu is doped in the Fe position, and the doping amount is optimized. The influence of the double coupling effect of coating and doping on the structure and properties of LiFePO4 cathode materials is systematically discussed. The local XRD results of the doped samples show that the diffraction peaks of the doped samples move to the small angle grain boundaries, and the lattice spacing of the materials increases, which is due to the large radius of Eu ions. The experimental results show that the dual coupling of carbon coating and ion doping can improve the conductivity of LiFePO4 cathode materials and improve its electrochemical performance. When the doping amount of Eu is 2%, the electrochemical performance of LiFe0.98Eu0.02PO4/C cathode material is the best. The initial charge–discharge capacity of 153/144.4 mAh·g−1 can be obtained at 0.5C, and a discharge capacity of 143.2 mAh·g−1 remains after 50 cycles. The exploration of this experiment provides a reasonable solution for slowing down the pollution of metallurgical waste to the environment and reducing the production cost of LIBs. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of the Leaves of Castanopsis eyrei led to the isolation of two new natural truxinate derivatives and a new phenyldilactone. The structures of the new natural compounds were determined by spectroscopic methods and chemical evidence as 3,3',4,4'-tetrahydroxy-β-truxillic acid (1), 3,3',4,4'-tetrahydroxy-δ-truxillic acid (2), 3'-hydroxymaysedilactone A (3). Establishment of a Caenorhabditis elegans lipid metabolism model using GFP and mCherry fluorescently labeled lipid droplets to screen compound 3 for its activity in reducing lipid accumulation. [ABSTRACT FROM AUTHOR]

Through making the analysis of information spread in social networks,the supression of rumors,error information and other negative information was realized.Firstly,by analyzing the structure of social networks and the characteristics of node behavior,a method for the identification of opinion leader nodes was proposed based on the degree of intimacy between nodes in social networks.Then,the rumor propagation model and the analysis of nodes’ state transformation process were made when the rumor spread in social networks.At last,the control method was proposed to suppress the diffusion of rumors with the nodes’ closeness.

Two new isoflavone compounds, Dalhancei A (1) and Dalhancei B (2), along with a known compound epicatechin (3) were isolated from 80% methanol extract of the barks of Dalbergia hancei Benth. The structures of compounds 1–3 were elucidated by comparison with the literature and physical data analysis, including optical rotation, MS, 1D and 2D NMR spectra. Compounds 1 and 2 showed weak inhibitory activity against tyrosinase at 16.22 mmol/L, with inhibition rates of 42.23 ± 0.18% and 45.68 ± 0.17%, respectively; compound 1 exhibited weak inhibitory activity against α-glucosidase with the inhibition rate of 43.72 ± 0.22% at 5.41 mmol/L, compounds 2 and 3 had better α-glucosidase inhibitory activity than compound 1 with IC50 values of 0.90 ± 0.18 and 0.41 ± 0.17 mmol/L, respectively. [ABSTRACT FROM AUTHOR]

Three new compounds (6S,9S)-6′-galloyl-roseoside (1), purpurogallin ethyl carboxylate (2), and tibetana A (3) were isolated from 80% methanol extract of the leaves of Castanopsis tibetana Hance. Their structures were elucidated based on comprehensive spectroscopic methods and chemical data, including optical rotation, UV, MS, 1 D and 2 D NMR spectra. Compounds 1 and 3 were evaluated for their α-glucosidase inhibitory activity, pancreatic lipase inhibitory activity, and tyrosinase inhibitory activity. [ABSTRACT FROM AUTHOR]