知识在时间和空间上分布不均衡,具有场效应。借鉴物理学场论原理,基于知识属性,从知识存量、知识结构、知识水平、知识分布和知识流动5个方面,构建了知识场,运用矢量分析和场论等相关理论研究了知识场的测度,并从知识辐射的性质和影响因素出发,建立了场源知识辐射效果测度模型。然后,以上海为中心的长三角地区为例进行了实证分析，结果表明,场源城市对周边地区具有明显的知识辐射效应,而且存在较大的提升空间。最后,提出了增强知识辐射效应的对策。

Knowledge flows is unevenly distributed in time and space with field effect. It has constructed a knowledge field which was gathered by multinational R&D center clustering based on knowledge attributes. Then, it has established a field sources index system and model for determination of strength from 5 aspects which are knowledge stock, knowledge construction, knowledge level, knowledge distribution and knowledge flows to do measurement and analysis field sources in Shanghai. The results show that there are conspicuous knowledge radiation effects for source field cities to surrounding area, but there is a big room for improvement. Finally, on the basis of research, it proposes strategy to strengthen the conspicuous knowledge radiation effects.