为解决关注的研究领域中检索关键文献效率低的问题,本研究利用R语言bibliometrix包,以土壤氨(NH3)挥发为例,进行文献计量分析(包括关键词共现分析、共词分析及高被引论文分析),探索文献计量分析在Web of Science核心数据库中精确快速检...为解决关注的研究领域中检索关键文献效率低的问题,本研究利用R语言bibliometrix包,以土壤氨(NH3)挥发为例,进行文献计量分析(包括关键词共现分析、共词分析及高被引论文分析),探索文献计量分析在Web of Science核心数据库中精确快速检索文献的方法。研究发现,第一次文献检索时,输入少量简单关键词(土壤氨挥发),检索出来的文献数量达到3573篇,且其中的高被引论文多数与主题词关系不大。对第一次检索结果进行文献计量分析,根据关键词聚类、共词分析结果,增加了关键词进一步检索文献,进行上述过程2次后,检索的文献数目已降至160篇,其中的Top 10高被引论文与检索主题(土壤NH3挥发)紧密相关。此时,假设需进一步精确查找关于土壤NH3挥发与水分、温度、管理方面研究文献,再次分别增加关键词进一步检索,分别检索出26、20和28篇相关文献,且关键词及高被引论文分析结果也再次验证了方法的准确性。本研究中利用文献计量分析快速检索权威、关键文献的方法切实可行。在大数据背景下,文献计量结合R-bibliometrix工具,有助于快速、精确地检索关键文献、获取科研思路及解决方法。展开更多
[Objective] The study about the nitrogen releasing law of bamboo-charcoal coated urea and the biologic utilization effect was to find the coated urea with high efficiency,low price and simple production technology.[Me...[Objective] The study about the nitrogen releasing law of bamboo-charcoal coated urea and the biologic utilization effect was to find the coated urea with high efficiency,low price and simple production technology.[Method]Two kinds of bamboo-charcoal coated urea(BCCU)with different coating thickness were made by using bamboo-charcoal and macromolecule polymer as coating material.The experiments of soil eluviate,ammonia volatilization in corn field and potted plant of corn were conducted to study the nitrogen releasing law and the biologic utilization effect of self-made BCCU.[Result]The BCCU showed some slow-release capability and their accumulated nitrogen releasing rates in 29 d were 9.93%-16.27% lower than that of normal urea.Compared with the normal urea,the volatilization rate of ammonia in BCCU reduced to 16.66%-31.8%,the biomass of corn and nitrogen utilization rate increased by 12.8%-24.1% and 10.5%-16.99%,respectively.[Conclusion]Bamboo-charcoal in coated urea not only had some slow-release capability,but also had some adsorbability,which would reduce the eluviation and volatilization of nitrogen and protect environment from N pollution.展开更多
文摘为解决关注的研究领域中检索关键文献效率低的问题,本研究利用R语言bibliometrix包,以土壤氨(NH3)挥发为例,进行文献计量分析(包括关键词共现分析、共词分析及高被引论文分析),探索文献计量分析在Web of Science核心数据库中精确快速检索文献的方法。研究发现,第一次文献检索时,输入少量简单关键词(土壤氨挥发),检索出来的文献数量达到3573篇,且其中的高被引论文多数与主题词关系不大。对第一次检索结果进行文献计量分析,根据关键词聚类、共词分析结果,增加了关键词进一步检索文献,进行上述过程2次后,检索的文献数目已降至160篇,其中的Top 10高被引论文与检索主题(土壤NH3挥发)紧密相关。此时,假设需进一步精确查找关于土壤NH3挥发与水分、温度、管理方面研究文献,再次分别增加关键词进一步检索,分别检索出26、20和28篇相关文献,且关键词及高被引论文分析结果也再次验证了方法的准确性。本研究中利用文献计量分析快速检索权威、关键文献的方法切实可行。在大数据背景下,文献计量结合R-bibliometrix工具,有助于快速、精确地检索关键文献、获取科研思路及解决方法。
基金Supported by the Special Foundation of"Guangxi NewCentury National Ten,Hundred and Thousand Talent Project"(2004217)the Sci-ence Foundation of Guangxi Province(Guikeji0575103)~~
文摘[Objective] The study about the nitrogen releasing law of bamboo-charcoal coated urea and the biologic utilization effect was to find the coated urea with high efficiency,low price and simple production technology.[Method]Two kinds of bamboo-charcoal coated urea(BCCU)with different coating thickness were made by using bamboo-charcoal and macromolecule polymer as coating material.The experiments of soil eluviate,ammonia volatilization in corn field and potted plant of corn were conducted to study the nitrogen releasing law and the biologic utilization effect of self-made BCCU.[Result]The BCCU showed some slow-release capability and their accumulated nitrogen releasing rates in 29 d were 9.93%-16.27% lower than that of normal urea.Compared with the normal urea,the volatilization rate of ammonia in BCCU reduced to 16.66%-31.8%,the biomass of corn and nitrogen utilization rate increased by 12.8%-24.1% and 10.5%-16.99%,respectively.[Conclusion]Bamboo-charcoal in coated urea not only had some slow-release capability,but also had some adsorbability,which would reduce the eluviation and volatilization of nitrogen and protect environment from N pollution.