A Review on Self-Cleaning Coatings for Tunnels

Self-cleaning coatings for tunnels can effectively remove dust and stains accumulated over the surface of tunnel linings and their appurtenances due to the closed environment and poor ventilation. This paper systematically introduces the current research status of self-cleaning coatings for tunnels, focusing on the development of super-hydrophobic self-cleaning coatings, superamphiphobic self-cleaning coatings, exhaust gas degradation coatings, fire retardant coatings, and tunnel de-icing coatings. The advantages and disadvantages of the five functional coatings are then briefly described, and the problems of self-cleaning coatings for tunnels at the present stage are pointed out. Finally, the development direction of self-cleaning coatings for tunnels is proposed to provide a reference for the research and application of self-cleaning coatings for tunnels.

RESEARCH STATUS AND DEVELOPMENT TREND OF MECHANIZED STRAW RETURNING TECHNOLOGY. A REVIEW

As the application of agricultural mechanized production technology becomes more and more extensive, the application of mechanized straw returning technology has become more and more valuable. The mechanized return of straw to the field is a time-saving and labor-saving technology. It is an effective way to achieve sustainable agricultural development and is of great significance to the development and progress of modern agriculture. This article analyzes the current research status of mechanized straw returning to the field, discusses the process structure and characteristics of different mechanized straw returning methods, and focuses on the analysis of the composite technology of straw returning to the field. At the same time, the key problems of straw returning to the field, such as the length of straw not meeting the standard, the shallow depth of straw returning to the field, and the uneven distribution of straw, are put forward and analyzed. By taking the cover and burial rate of straw on the soil surface and the spatial distribution uniformity of straw in the soil as the performance evaluation indexes of straw mechanized field return, each index is elaborated. Finally, two major development trends are proposed: the development of mechanized straw returning to the field from a single process to a composite process, and the effect of straw returning to the field towards uniform mixed burying and precise control.