Hunan Nonferrous Metal Research Institute

ABSTRACT As a novel class of nitrogen‐containing heterocyclic compounds, imidazopyridine uracils serve as the core scaffold in this study, where 16 derivatives were designed and synthesized with oxazosulfuron as the lead compound. The chemical structures of the target compounds were fully characterized and confirmed by proton nuclear magnetic resonance spectroscopy ( 1 H NMR ), carbon‐13 nuclear magnetic resonance spectroscopy ( 13 C NMR ), and high‐resolution mass spectrometry ( HRMS ). Nilaparvata lugens , Plutella xylostella , and Mythimna separata were selected as the test insects, and the insecticidal activities of the target compounds were determined in this research. Especially, compound 8a showed a mortality rate of 77.8% against N. lugens at 10 mg/L, which was superior to the activity of oxazosulfyl under the same conditions (51.9% mortality at 10 mg/L). In addition, compound 9j exhibited a mortality rate of 25.0% against M. separata at a concentration of 1 mg/L, which was superior to that of oxazosulfyl under the same conditions (0% mortality at 1 mg/L). This study is intended to provide a theoretical reference for the subsequent research and industrial development of this class of novel insecticides.

ABSTRACT High‐nickel ternary materials are considered as promising cathode materials for lithium‐ion batteries, primarily due to their high specific capacity and energy density. However, the crystal structure of high‐nickel cathode materials undergoes significant changes during charge and discharge cycles. The accumulated stress leads to the formation and growth of microcracks along the inter‐particle boundaries, ultimately compromising particle integrity. Repeated volume contractions and expansions eventually cause further pulverization of the material. In this study, Al 3+ ion doping was employed to stabilize the layered structure of the high‐nickel ternary materials. Al 3+ ‐doped LiNi 0.8 Co 0.1 Mn 0.1 O 2 was synthesized by a one‐step solid‐state sintering method. The characterization confirmed that Al 3+ ions were successfully doped into the transition metal layers of the cathode material and formed stronger Al─O covalent bonds, which enhanced the stability of the bulk phase structure, suppressed phase transition, and microcracks. The cathode material doped with 1.5 mol.% Al 3+ exhibited excellent cycling stability, with a capacity retention rate increased by 15.01% after 600 cycles compared to the pristine specimen. In addition, Al 3+ doping reduces cation mixing and optimizes ion transport kinetics, the discharge capacity reached 145.5 mAh·g −1 at 10 C rate. Therefore, achieving Al 3+ ion doping through co‐lithium sintering provides an effective strategy for improving the performance of high‐nickel cathode materials in lithium‐ion batteries.

2050 Al-Li alloy has been widely used in aerospace and marine industry because of its advantages such as light weight, but its corrosion failure has limited its use to a certain extent, so the study of the corrosion mechanism of the alloy is particularly important. In this paper, the mechanism of intergranular corrosion (IGC) of 2050 Al-Li alloy was studied through electron backscattering diffraction (EBSD) by changing the pre-deformation direction (0°, 30°, 60° and 90°). It is found that the grain size changes obviously by changing the pre-deformation direction, and the IGC rate will be accelerated when the grain size is reduced. In the study of grain orientation, it is found that the atomic arrangement density of different orientation crystal faces will also affect the IGC properties. The higher the atomic arrangement density of the crystal surface, the better the corrosion performance. Therefore, the crystal grain orientations of the alloy, in order from smallest to largest IGC rate, are (111), (101) and (001). In addition, it is found that the grain misorientation also has a direct effect on the IGC properties. The smaller the misorientation, the better the corrosion performance.