taking Xinjiang as the study center taking Jingxing region as the center 中国棉花技术进步及其效率研究：以新疆产区为中心：taking Xinjiang as the study center taking Xinjiang as an example taking Yunnan as the case taking the shengli as the center taking the Ming and Qing Dynasties as the center taking Shenzhen as the case taking Zhejiang as an example