Abstract:    The creativity of researchers varies significantly at different stages of their careers. A study by Nature shows that there is a peak  in the career of researchers, and most scientists experience only one peak . The common view is that researchers′ creativity follows an "inverted U-shaped" curve,  that is, at the beginning of their careers, the creativity of researchers is at a low level, then gradually increases to reach the peak, and then gradually declines after the peak. Academic performance is an important manifestation of creativity. The analysis of the differences of academic performance in different stages of scientific researchers′ career is helpful for the research managers to better understand the law and trajectory of talent growth and provide a basis for the evaluation and management policies of scientific and technological talents.
   In this paper, publication and citation data of Web of Science database is used as data source, and 736 researchers whose career in virology had been over 30 years were selected as the research objects. The career of researcher is divided into 6 stages with a time window of 5 years. Firstly, the changing laws of researchers′ productivity, academic influence and cooperation ability at various stages are discussed. Selecting a few indicators such as No. of papers, Times cited, i10-index, COPP, COPS, using descriptive statistical analysis method, the 9 index values of 736 scholars in 6 career stages were calculated respectively, and ploting the change curve of each index in different stages. Through the analysis of the shape of the curve to reflect the scientific research personnel in the 30 years of academic performance in his career change. Secondly, whether the differences in the academic performance of researchers existing between different stages is explored. For each indicator, the index values of 736 authors at each stage were taken as a set of data, 6 sets of data were obtained in total, and 15 sets of data were obtained in pairs. Any two groups are tested using the one-way analysis of variance to explore whether there were differences in academic performance of researchers at different stages. If the variance is homogeneous, the difference between the two groups is significant according to the ANOVA table, and else, Aspin-Welch test is used to judge whether the difference is significant.
The results show that in the first five years of career, researchers′ productivity and academic influence are at a low level, but at this time, the participation of researchers is high, and they are the main contributors and implementers of research work. During the 6-20 years of their career, researchers gradually transition from the main force of scientific research to the leadership role of the research team, and the overall academic influence shows a stable and small rise. During the 21-30 years of their career, productivity is still growing, but at a slower rate, researchers are still playing leading roles, and academic influence is at the highest level after 20 years of accumulation. During the 30-years career, the collaborative ability of researchers has grown rapidly. In talent evaluation, the evaluation methods and indicators should be carefully selected according to the growth characteristics of researchers at different stages of their career and combined with the evaluation purpose.

Key words:  career, scientific research productivity, academic influence, collaborative capacity