In a chloride environment, taking reinforced concrete structures as the research object, the corrosion rate of reinforcement determines its corrosion expansion because multiple coupling parameters will affect the corrosion rate of reinforcement, which is extremely difficult to effectively predict. In this paper, 144 sets of experimental data were collected and sorted out by reading the relevant literature, and six empirical models for predicting the corrosion rate of steel bars were compared and analyzed based on these experimental data. Based on the investigations, a new empirical model is proposed for predicting the corrosion rate of reinforcement, and the relevant influencing factors are considered in the new model. By comparing the 144 sets of experimental data and 90 experimental data for this paper, the new prediction model can well predict the corrosion rate of reinforcement. Furthermore, the time variability of the new prediction model is verified. The probability distribution characteristics of seven prediction models are obtained through model error analysis, which provides a theoretical basis for the next step of concrete cover cracking and reliability analysis.

We study the spatial structure of a Bose-Einstein Condensate (BEC) with a space-dependent s-wave scattering length in a combined trap. There exists a space-dependent nonlinear atomic current in the system. The atomic current has an important influence on the spatial structure of the BEC. Research findings reveal that a large chemical potential can effectively suppress the chaotic spatial structure in the BEC system. Due to the large chemical potential, a strong atomic current is necessary to make the system lose its periodic spatial structure and lead the system into a chaotic spatial structure. But when the atomic current intensity exceeds a critical value, the chaotic spatial structure of the BEC will be completely eliminated and the system will always be kept in a series of single-periodic states as the atomic current becomes stronger. For a very weak atomic current, the spatial structure of the BEC is very sensitive to the intensity of the atomic current and a very small change of the intensity can dramatically change the spatial structure of the BEC. The effects of the combined trap parameters on the spatial structure of BECs are also discussed.