Unmanned Aerial Vehicle Control of Major Sugarcane Diseases and Pests in Low Latitude Plateau

This research was aimed at the defects in traditional artificial spraying control method and the problems such as the difficulty in pesticides applying,labor shortage and low operating efficiency in the middle and late stage of sugarcane high stalk crops.The aerial pesticide application technology for sugarcane main diseases and pests was systematically developed and demonstrated from the aspects of aircraft type choice,selection of special pesticides and auxiliaries,integration of pesticides and equipment,field operation,technical specifications,and large-scale application organization mode.The UAV model and flight technical parameters suitable for the sugarcane planting area in low-latitude plateau were analyzed,and the optimal agent formulation combination and application technology of the UAV flight control were screened out,and the UAV flight control was applied to the major sugarcane pests and diseases control in the low-latitude plateau in large scale(UAV flight control was popularized and applied to 15 527 hm 2 in 2018).The research results provided mature whole-process technical support for the normalization of the application of the UVA flight control of major sugarcane pests and diseases.The UAV control technology for major sugarcane pests and diseases had the advantages of ultra-low pesticides applying dosage and high operating efficiency,and could effectively solve the problems such as the difficulty in pesticides applying,labor shortage and low operating efficiency in the middle late growth stage of high stalk crops.This technology successfully opened up a simple,efficient and new way for the effective control of major sugarcane pests and diseases,and practically accelerated the process of integrated control and prevention of sugarcane pests and diseases.In addition,this technology had an extremely significant effect on reducing the loss of sugarcane farmers and enterprises caused by the epidemic and outbreak of sugarcane pests and diseases,increasing sugarcane yield and sugar content.At the same time,this technology played an important role in realizing the whole-process precise control of sugarcane pests and diseases,improving the quality and increasing the efficiency of sugarcane,and guaranteeing the national sugar safety.

Process and Component Analysis on S-CO_(2)Cooling Wall in the Coal-fired Boiler Power System

The supercritical carbon dioxide(S-CO_(2))cooling wall in coal-fired boiler suffers from severe fragile crisis due to the high temperature of S-CO_(2).The analysis of both heat transfer at process scale and cooling wall arrangement at component scale were carried out in present work.At the process scale,the difference in heat transfer performance between the smooth tube and the rifled tube were identified,especially the location of maximum outer wall temperature of cooling wall.The 1-D mathematical model for thermal-hydraulic analysis of S-CO_(2)furnace cooling wall tubes was then developed.At the component scale,the coupled model of combustion and S-CO_(2)heat transfer is employed for studying the thermal-hydraulic performance of rifled-spiral(R-S)and smooth-spiral(S-S)cooling wall arrangements.The maximum outer wall temperature of R-S cooling wall is 16.38℃lower while the pressure drop increases by 2.33 times compared with the S-S cooling wall.Considering the pressure drop penalty on cycle efficiency of S-CO_(2)boiler power system,the R-S cooling wall is not recommended,while the S-S cooling wall should be carefully arranged in S-CO_(2)boilers.