Abstract: A matching design method of static stiffness for a combined box body structure of a large reducer is provided, including the following steps, building a transmission system model and an initial structure model and obtaining load data; performing a statics analysis; obtaining primary design variables and design responses; constructing design variables; constructing a static stiffness matching target of a combined box body; constructing an objective function; setting constraint conditions; constructing a response surface proxy model; constructing a static stiffness matching optimization model of combined box body; obtaining optimal design variables and obtaining an optimal structure model of the box body; performing the statics analysis on the optimal structure model of the box body, and performing a contrastive analysis with statics analysis results of the corrected box body two-dimensional unit finite element model to confirm optimization effects.

Abstract: A file sharing method, a system, and a related device are provided, which are applicable to the field of internet technologies. The file sharing method includes, after detecting a sharing operation instruction of an original file, a terminal device obtains a cloud identifier corresponding to the original file, the terminal device obtains, from the cloud disk server, the original file corresponding to the cloud identifier, and the terminal device sends the obtained original file corresponding to the cloud identifier to a target sharing terminal, so that sharing of a file stored in the cloud disk server can be implemented without jumping by using an address link.

Abstract: Disclosed is a two-stage frequency selection method and device for microwave frequency sweep data. The method includes: acquiring microwave frequency sweep data; performing frequency selection on the microwave frequency sweep data by using a random forest-recursive feature elimination algorithm, taking a preset parameter in the random forest-recursive feature elimination algorithm as a hyper-parameter, changing the value of the hyper-parameter, and generating a series of candidate frequency subsets within different frequencies; building prediction models on the basis of the frequency sweep data corresponding to the candidate frequency subsets of different frequencies; evaluating the performance of each prediction model by means of 10 fold cross validation, and calculating evaluation index values of model performance; and taking the evaluation indexes as a voting basis, and selecting an optimal frequency subset by using a majority voting method.

Abstract: A weeding machine and a weeding method for seedlings in a paddy field are disclosed. The weeding machine includes a paddy field power chassis, a lifting hydraulic cylinder, a parallelogram suspension frame, a weeding frame, a transmission assembly, and weeding units. The paddy field power chassis vertically adjusts the working depth of the weeding machine through the parallelogram suspension frame and the lifting hydraulic cylinder. The power is transmitted to the weeding units by the transmission assembly. The weeding units are used for pulling out weeds between rows and feeding the weeds to weed chopping channels. Spiral weed chopping knives are used for chopping the weeds and conveying the weeds to feeding channels. Bidirectional variable-pitch augers are used for conveying the chopped weeds to discharge openings of the feeding channels under pressure and discharging the chopped weeds for burying weeds between plants.

Abstract: An infrared ray gas burner with windproof function consisting of a nozzle (1), an ejector, a gas-air mixing chamber, an infrared combustion radiant panel and a burner mounting plate, wherein a wind-proof plate is mounted on the front end of the burner, a splitter plate is mounted in the gas-air mixing chamber of the burner, an air inlet is provided outside the periphery of the infrared combustion radiant panel, an air outlet is provided in the external cavity housing, the proportional relationship between the areas of the air inlet, the air outlet and the infrared combustion radiant panel is 1:(2.5-5):(14-20). The gas-air mixture overflowing from the infrared combustion radiant panel impacts against the outside wind to achieve a pressure balance, so as to obtain a stable burning and a good windproof effect.