Abstract: Provided are a precursor compound of a tetracyclic hydrocarbon and a preparation method thereof, and a tetracyclic hydrocarbon and a preparation method and use thereof. The precursor compound of the tetracyclic hydrocarbon with a structure shown in formula I has a polycyclic structure. The precursor compound is subjected to hydrodeoxygenation so as to be prepared into the tetracyclic hydrocarbon with a structure shown in formula II that has a high density (0.986 g/cm3), a high calorific value (41.14 MJ/L), and a low freezing point (less than ?60° C.).

Abstract: Provided are a precursor compound of a tetracyclic hydrocarbon and a preparation method thereof, and a tetracyclic hydrocarbon and a preparation method and use thereof. The precursor compound of the tetracyclic hydrocarbon with a structure shown in formula I has a polycyclic structure. The precursor compound is subjected to hydrodeoxygenation so as to be prepared into the tetracyclic hydrocarbon with a structure shown in formula II that has a high density (0.986 g/cm3), a high calorific value (41.14 MJ/L), and a low freezing point (less than ?60° C.).

Abstract: A method for stress-induced magnetic field signal acquisition and stress measurement is disclosed. The method can include the following steps: a1, conducting AC magnetization on a to-be-tested structure by using an AC magnetic field with preset frequencies and strengths, and acquiring the excitation magnetic field signals in at least one cycle; a2, subtracting the excitation magnetic field signals in at least one cycle of a stress-free sample having the same material as the to-be-tested structure from the excitation magnetic field signals acquired in step a1 to obtain a stress-induced magnetic field signals of the to-be-tested structure; a3, quantitatively assessing the stresses in the to-be-tested structure by comparing the mean values of the stress-induced magnetic field signals acquired in step a2 with the pre-calibrated relationship of stresses and the mean values of the stress-induced magnetic field signals for the material of the to-be-tested structure.

Abstract: A method for stress-induced magnetic field signal acquisition and stress measurement is disclosed. The method can include the following steps: a1, conducting AC magnetization on a to-be-tested structure by using an AC magnetic field with preset frequencies and strengths, and acquiring the excitation magnetic field signals in at least one cycle; a2, subtracting the excitation magnetic field signals in at least one cycle of a stress-free sample having the same material as the to-be-tested structure from the excitation magnetic field signals acquired in step a1 to obtain a stress-induced magnetic field signals of the to-be-tested structure; a3, quantitatively assessing the stresses in the to-be-tested structure by comparing the mean values of the stress-induced magnetic field signals acquired in step a2 with the pre-calibrated relationship of stresses and the mean values of the stress-induced magnetic field signals for the material of the to-be-tested structure.