The investigation was conducted to address the influence of different proportions of nitrogen fertilizer on superior and inferior grain filling of large-panicle type rice cultivars by the method of differential proteomics.

They studied and analyzed information on the concepts of "vulnerability and vulnerable group" and "disadvantage and disadvantaged group" from sources at home and abroad, worked out the theory of "physically vulnerable group" in accordance with the characteristics of PE teaching, and expatiated on the important role this theory would play in PE teaching.