I had a whim last night to start recording my daily scientific research, so let's start today. To be honest, I didn't do anything today. Recently, we have proposed a new method for constructing a divergence-free matrix-valued kernel function defined through integration. Currently, we are conducting numerical experiments to test its advantages. However, the experimental results were incorrect, and I suspect that there was an error in the derivation process. I need to calm down and check the process later.