No abstract

The long-distance traditional belt conveyor driven by a single high-power motor has the problems of excessive tension increments and sharp fluctuations in speed and tension. This paper designs a distributed permanent magnet direct drive belt conveyor system. The dynamic model of the conveyor belt unit and the permanent magnet motor is analyzed. The multi-motor ring coupling control strategy and the double sliding film direct torque control strategy of the belt conveyor system are formulated. The mechanical-electrical coupling dynamic model of the belt conveyor system is built. Using MATLAB/Simulink modeling and simulation, the vector control strategy and electromechanical coupling dynamic behavior of the traditional belt conveyor system and the distributed permanent magnet direct drive belt conveyor system under light load start-up and local variable load operation conditions are studied. The results show that: the distributed permanent magnet direct drive belt conveyor system significantly reduces the peak of conveyor belt tension increment; the time spent under the starting light-load operation condition is shorter, and the fluctuation amplitude of speed and tension is smaller; it is possible to reduce the speed and tension fluctuation range of the conveying system and improve the robustness of the conveying system under local variable load conditions. Experiments have verified that increasing the number of drive motors in a conventional belt conveyor can suppress the disturbance caused by local load changes, and the distributed permanent magnet direct-drive belt conveyor has better dynamic regulation performance.

Fat content (FC) partially determines rice grain quality. The objective of this study was to identify stably expressed quantitative trait loci (QTL) for FC. A total of 85 inbred lines derived from the backcross between Sasanishiki (japonica, as the recurrent parent) and Habataki (indica) were used to detect QTLs for rice fat content. Seven QTLs (denoted as qFC‐1, qFC‐2, qFC‐3, qFC‐6, qFC‐10, qFC‐11, and qFC‐12) were detected on chromosomes 1, 2, 3, 6 10, 11, and 12, respectively, using inclusive composite interval mapping (ICIM) method. Among them, three major QTLs (qFC‐3, qFC‐6, and qFC‐11) with large effect were further confirmed across two different environments using some chromosome segment substitution lines (CSSLs), where Habataki was used as the donor parent and Sasanishiki as the recurrent parent. Further experiments showed that one of the major QTLs (qFC‐11) could increase fat content, fat index, and grain yield together. To our knowledge, qFC‐11 is a newly detected stable QTL that will provide new opportunities for improving rice fat content through marker‐assisted selection.

No abstract

No abstract