针对四旋翼飞行器在依靠地标导航完成动平台自主降落任务中存在的目标易丢失、地标定位死区大和降落可靠性差等问题,设计了一种基于复合地标导航的动平台四旋翼飞行器自主优
Background:Recent studies have indicated that an imbalance of gut microbiota is associated with the development of type 1 diabetes mellitus (T1DM) and there is
目的探讨精氨酸增强胃肠外营养对胰腺癌导管动脉化疗栓塞术(TACE)患者血清血管内皮生长因子(VEGF)和碱性纤维母细胞生长因子(bFGF)水平的影响及其临床意义。方法采用酶联免疫吸附法
Background:The incidence of diabetic nephropathy (DN) increases year by year.However,clinical characteristics of DN patients on maintenance hemodialysis (MHD) w
首先提出了一类含较少运动副四支链两转一移三自由度(2R1T)并联机构(PMs) 2RPU-UPR-RPR和2UPR-RPU-RPR,然后提出了极限约束力螺旋系的概念,分析四支链2R1T并联机构末端的极限