Dairy industry is an indispensable component of modem agriculture. How to improve informatization level and technology content of dairy industry and progress informationalization construction process of pastures has b...Dairy industry is an indispensable component of modem agriculture. How to improve informatization level and technology content of dairy industry and progress informationalization construction process of pastures has been one of the most popular topics in development of dairy industry in China. Compared with the countries with developed dairy industry worldwide, dairy industry in China is featured by not high informationization level and backward modernization level at the present stage. However, development and maturity of related technologies for pasture informatization construction provides a significant opportunity for transformation and upgrading and leaping development of dairy industry in China.展开更多
Large reflector antennas are widely used as radio telescopes and active main reflectors are generally applied to improve the surface accuracy. Considering that the high cost has been one important problem in engineeri...Large reflector antennas are widely used as radio telescopes and active main reflectors are generally applied to improve the surface accuracy. Considering that the high cost has been one important problem in engineering, it is worth discussing whether it is necessary to install actuators on all the panels. Thus, in this paper, a hybrid-panel-based new design idea for large reflector antenna is proposed. Assuming that the actuators are installed only in the region of the reflector with large deformations and there are no actuators in other region to reduce the actuator number, the surface accuracies and the corresponding electromagnetic(EM) performances calculated by three different panel adjustment strategies are compared. The most effective method is that the deformed reflector should be first preadjusted to reduce the gravity deformation and then the panels equipped with actuators should be adjusted to the locations determined by the best fitting reflector(BFR) derived by the deformed reflector with no actuators. A 35 m reflector antenna is adopted as an example to calculate the surface accuracy and EM performance when parts of the panels are equipped with actuators. The simulation results show that there is no need to install actuators on all panels and the presented method can greatly reduce the number of actuators with guaranteed surface accuracy. Thus, during the antenna structural design phase, once the surface accuracy requirement is given, the number of actuators can be minimized to reduce the manufacturing and maintenance costs as much as possible. This paper can provide valuable guidance for the design of an active main reflector with hybrid panels.展开更多
基金Supported by Open Science and Technology Cooperation Project of Henan Province(162106000017)Science and Technology Project Benefiting People in Henan Province(152207110004)Key Science and Technology Research Project of Puyang City(150109)
文摘Dairy industry is an indispensable component of modem agriculture. How to improve informatization level and technology content of dairy industry and progress informationalization construction process of pastures has been one of the most popular topics in development of dairy industry in China. Compared with the countries with developed dairy industry worldwide, dairy industry in China is featured by not high informationization level and backward modernization level at the present stage. However, development and maturity of related technologies for pasture informatization construction provides a significant opportunity for transformation and upgrading and leaping development of dairy industry in China.
基金supported by the National Key Research and Development Program of China (Grant No. 2021YFC2203600)National Natural Science Foundation of China (Grant Nos. 52005377 and 51975447)+1 种基金Youth Innovation Team of Shaanxi Universities (Grant No. 201926)Fundamental Research Funds for the Central Universities (Grant Nos. JB210404 and JB210403)。
文摘Large reflector antennas are widely used as radio telescopes and active main reflectors are generally applied to improve the surface accuracy. Considering that the high cost has been one important problem in engineering, it is worth discussing whether it is necessary to install actuators on all the panels. Thus, in this paper, a hybrid-panel-based new design idea for large reflector antenna is proposed. Assuming that the actuators are installed only in the region of the reflector with large deformations and there are no actuators in other region to reduce the actuator number, the surface accuracies and the corresponding electromagnetic(EM) performances calculated by three different panel adjustment strategies are compared. The most effective method is that the deformed reflector should be first preadjusted to reduce the gravity deformation and then the panels equipped with actuators should be adjusted to the locations determined by the best fitting reflector(BFR) derived by the deformed reflector with no actuators. A 35 m reflector antenna is adopted as an example to calculate the surface accuracy and EM performance when parts of the panels are equipped with actuators. The simulation results show that there is no need to install actuators on all panels and the presented method can greatly reduce the number of actuators with guaranteed surface accuracy. Thus, during the antenna structural design phase, once the surface accuracy requirement is given, the number of actuators can be minimized to reduce the manufacturing and maintenance costs as much as possible. This paper can provide valuable guidance for the design of an active main reflector with hybrid panels.
