确定一定数量的高频词是识别研究热点的基础性工作，但是目前对于如何确定高低词频的分界点还缺乏客观的、行之有效的方法。本研究以2002～2011年收录入Web of Science SCI中934篇科学计量相关文献为语料，分析了齐普夫定律中的常数变...确定一定数量的高频词是识别研究热点的基础性工作，但是目前对于如何确定高低词频的分界点还缺乏客观的、行之有效的方法。本研究以2002～2011年收录入Web of Science SCI中934篇科学计量相关文献为语料，分析了齐普夫定律中的常数变化规律，进而基于统计分析创建了一种确定语料中高低词频分界点的新方法。通过比较分析发现，相对于已有的方法，本方法在识别高频词方面具有数量和稳定性两方面的双重优势。应用该方法识别科学计量学的研究热点，发现10年来科学计量研究领域已形成一系列成熟、稳定的研究议题，如引文分析、期刊影响因子、产出评价等。同时这一领域也处于不断发展之中，引文分析方法的成熟和h指数等新型研究议题的兴起使这一领域的研究正在走向深化。展开更多
With urbanization and population migration,some Chinese cities fall into decline whereas others prosper.Using nighttime light data,we redefine the city based on economic function and evaluate the city size distributio...With urbanization and population migration,some Chinese cities fall into decline whereas others prosper.Using nighttime light data,we redefine the city based on economic function and evaluate the city size distribution in representative countries.The results provide evidence not only for Zipfs law,but also for a distortion in China s current city size distribution.This study proposes a feasible method to predict urban population distribution based on the role of geographical factors in regional development,following the idea of spatial equilibrium.This prediction suggests that the divergence of city size in China tends to be pronounced,with inter-regional income disparity being narrowed and the city size distribution following Zipfs law.The Chinese government should further relax restrictions on population inflow into large cities and prepare for more migration in the future.展开更多
文摘确定一定数量的高频词是识别研究热点的基础性工作，但是目前对于如何确定高低词频的分界点还缺乏客观的、行之有效的方法。本研究以2002～2011年收录入Web of Science SCI中934篇科学计量相关文献为语料，分析了齐普夫定律中的常数变化规律，进而基于统计分析创建了一种确定语料中高低词频分界点的新方法。通过比较分析发现，相对于已有的方法，本方法在识别高频词方面具有数量和稳定性两方面的双重优势。应用该方法识别科学计量学的研究热点，发现10年来科学计量研究领域已形成一系列成熟、稳定的研究议题，如引文分析、期刊影响因子、产出评价等。同时这一领域也处于不断发展之中，引文分析方法的成熟和h指数等新型研究议题的兴起使这一领域的研究正在走向深化。
基金The authors acknowledge research support from the National Natural Science Foundation of China(Nos.72073094 and 71834005)Shanghai Institute for National Economy,Shanghai Institute of International Finance and Economics,and the China Merchants Charitable Foundation.
文摘With urbanization and population migration,some Chinese cities fall into decline whereas others prosper.Using nighttime light data,we redefine the city based on economic function and evaluate the city size distribution in representative countries.The results provide evidence not only for Zipfs law,but also for a distortion in China s current city size distribution.This study proposes a feasible method to predict urban population distribution based on the role of geographical factors in regional development,following the idea of spatial equilibrium.This prediction suggests that the divergence of city size in China tends to be pronounced,with inter-regional income disparity being narrowed and the city size distribution following Zipfs law.The Chinese government should further relax restrictions on population inflow into large cities and prepare for more migration in the future.
