In this paper we discuss the linear combination of derivations in prime rings which was initiated by Niu Fengwen.Our aim is to improve Niu's result.For the
从某种程度上来,工具的发明从根源上改变了人类与自然的相处方式。从石器、青铜、铁器、蒸汽和电气,再到如今的信息时代,工具的演进无形间记录着人类文明的发展史,成为人类探
二十多年前,Intel、微软、Oracle、SAP等企业凭借处理器、操作系统、数据库和ERP等核心技术,构建了生态帝国,取得了成功。他们构建了帝国,同时也筑起了城墙。在高筑的城墙后,
目的用随机扩增多态性DNA(random amplified polymorphic DNA,RAPD)技术对内蒙古产丹参进行多态性分析。方法通过CTAB法提取内蒙古产丹参干品DNA,用10个条随机引物进行RAPD分析
In this paper, we consider the electromagnetic scattering by a periodic chiral structure. The media is homogeneous and the structure is periodic in one directio
目的总结基层医院胃溃疡穿孔修补术的临床效果及体会。方法回顾性分析胃溃疡穿孔修补术60例患者的临床资料。结果60例均顺利完成手术,治愈出院,无术后并发症发生,术后1年随访