Abstract: A a plant composite corrosion inhibitor for an oil field and a preparation method thereof belong to the technical field of preparation of oil field chemical agents. The plant composite corrosion inhibitor comprises a first plant ingredient, a second plant ingredient, a corrosion inhibition synergist and an organic solvent. The first plant ingredient is zeaxanthin and a derivative thereof obtained by supercritical CO2 extraction of marigold; the second plant ingredient is prepared from luffa leaves, guava leaves and eclipta according to a mass ratio of 5:8:9; the corrosion inhibition synergist is prepared by mixing potassium iodide, 8-hydroxyquinoline and sodium dodecyl benzene sulfonate according to a mass ratio of 3:4:2; and the organic solvent is ethanol with a mass concentration of 82%. The composite corrosion inhibitor has a good corrosion inhibition effect, and reduces harmful chemical ingredients in the corrosion inhibitor.

Abstract: This disclosure discloses lane line detection methods and devices. In an implementation, features extracted by different layers of the neural network are fused to obtain a fused second feature map, so that the second feature map obtained through fusion processing has a plurality of layers of features. The fused second feature map has a related feature of a low-layer receptive field and a related feature of a high-layer receptive field. Afterwards, an output predicted lane line set is divided into groups, where each predicted lane line in each group has an optimal prediction interval.