School of science Yunnan Agricultural University Kunming 650201 Yunnan Province China;
School of science Yunnan Agricultural University Kunming 650201 Yunnan Province China;
The First Company of China Eighth Engineering Bureau Led Jinan 250101 Shandong Province China;
School of science Yunnan Agricultural University Kunming 650201 Yunnan Province China;
Portfolio investment; Mean-variance model; Long-term investment; CAPM; Dynamic adjustment;