No abstract

The indoles motifs are widely found in the nature. One of the efficient strategy to access the indole derivatives is through the direct C-H functionalization of indole framework itself under transition-metal catalysis. Herein, the research advances on the transition-metal-catalyzed C-H arylation of indoles are reviewed.

Simultaneous localization and mapping (SLAM) is the key technology for the automation of intelligent mining equipment and the digitization of the mining environment. However, the shotcrete surface and symmetrical roadway in underground coal mines make light detection and ranging (LiDAR) SLAM prone to degeneration, which leads to the failure of mobile robot localization and mapping. To address these issues, this paper proposes a robust LiDAR SLAM method which detects and compensates for the degenerated scenes by integrating LiDAR and inertial measurement unit (IMU) data. First, the disturbance model is used to detect the direction and degree of degeneration caused by insufficient line and plane feature constraints for obtaining the factor and vector of degeneration. Second, the degenerated state is divided into rotation and translation. The pose obtained by IMU pre-integration is projected to plane features and then used for local map matching to achieve two-step degenerated compensation. Finally, a globally consistent LiDAR SLAM is implemented based on sliding window factor graph optimization. The extensive experimental results show that the proposed method achieves better robustness than LeGO-LOAM and LIO-SAM. The absolute position root mean square error (RMSE) is only 0.161 m, which provides an important reference for underground autonomous localization and navigation in intelligent mining and safety inspection.

Abstract. This paper takes Australian TAFE project as the object of study and designs teaching team ability index system for Sino-foreign cooperative education of higher vocational colleges on the basis of TT-CMM model. The influence degree of each ability index on comprehensive score of team is tested through modeling, and relevant development suggestions are proposed. Teaching team ability teaching team standards of Sino-foreign cooperative education of higher vocational collegesJiang Lin and his team (2012) further studied teaching team ability evaluation on the basis of studying teachers' individual ability evaluation and improvement system based on CMM, proposed and constructed teaching team ability index system. We can see from their statement that, teaching team ability they studied is a comprehensive ability. Meanwhile, they constructed team ability maturity model TT-CMM and divided teaching team ability into five levels according to the maturity degree. This paper takes TAFE as the object of study, refers to TT-CMM model and combines actual conditions of higher vocational colleges which pay attention to skill training and requirements of Sino-foreign cooperative education to design TAFE teaching team ability index system. The influence degree of each ability index on comprehensive ability of the team is inspected by modeling.

In the context of Guangzhou and Foshan synchronization, this paper analyzes the impact of cities' synchronization on total factor productive with difference in differences model based on the panel data of 21 cities in Guangdong from 2000 to 2016. For further analyzing the source of cities' synchronization effect, the total factor productive is decomposed into technology progress and technology efficiency. The results show that the cities' synchronization of Guangzhou and Foshan can significantly improve their own total factor productive through the contributions of technology progress and technology efficiency. The other factors, such as Innovation investment, foreign direct investment, road infrastructure, have different types of influence on total factor productive. Moreover, total factor productive and technique progress of Guangdong province get improvements from 2001 to 2016, while technique efficiency, by contrast, is declining.

The direct transformation of N‐substituted indoline to isatin derivatives has been developed, this reaction employed cheap Cu catalyst and aqueous tert‐butyl hydroperoxide as an oxidant. Primary mechanism studies suggested that the indolines was initially oxidized to indoles which further undergo Cu‐catalyzed oxidation to isatins.

Green, healthy and sustainable is the theme of China’s current development. The environmental problems caused by rapid urbanization and industrialization need to be solved. Among them, soil pollution is the most significant problem, which is also the most closely related to people’s life and work. More and more scholars begin to pay attention to the problem of soil pollution, but there is still a lack of engineering methods to achieve the expected goal. The core of land engineering is the organic reconstruction of soil, through physical, chemical and biological remediation methods to achieve the optimization of soil structure, reduce or eliminate land pollution, to meet the different needs of people. Human settlement environment is a comprehensive study of urban problems. The author thinks that the essence of urban problems is land problems. Land economy, land environment and the social equity and justice decided by them are the main aspects that affect the development of human settlement. Through the remediation of contaminated land, the human settlement will be fundamentally improved. Land engineering has important practical significance for improving the living environment, and provides a feasible path for land ecological construction.