土壤深层碳库巨大,在全球碳循环中具有重要作用。为了深入理解深层土壤碳循环,分析深层土壤为主题的全球土壤碳循环研究的热点与前沿,以Web of Science核心合集为数据库,获取近25年以深层土壤为主题词的土壤碳循环研究文献(280篇)。通...土壤深层碳库巨大,在全球碳循环中具有重要作用。为了深入理解深层土壤碳循环,分析深层土壤为主题的全球土壤碳循环研究的热点与前沿,以Web of Science核心合集为数据库,获取近25年以深层土壤为主题词的土壤碳循环研究文献(280篇)。通过文献计量方法,分别对年文献发表量、研究区分布、研究主题热点等进行了统计与可视化分析。结果表明:(1)1995-2020年间,以深层土壤为主题词对土壤碳循环研究的发文数量逐渐增长,尤其是2010-2020年期间;(2)不同研究主题对深层土壤的定义不同,其中以土壤碳储量为主题的研究对深层土壤的定义深度最深,52.2%的文献对深层土壤定义深度超过60 cm;(3)农林、环境科学、土壤科学和生态学是深层土壤碳循环研究的主要领域;(4)研究热点主要集中在环境因素和土地利用变化对土壤碳储量、碳稳定性及碳剖面垂直变化的影响方面;(5)近几年,研究主题逐渐向微生物群落、激发效应、碳组分、碳稳定性等转变,研究对象扩展到了北极永久冻土。展开更多
Magnetic Fe304 nanoparticles were synthesized by co-precipitation method and the mercaptopurine (MER) drug-loaded magnetic microspheres were obtained through emulsion cross-linking methods. The efficiency of this ap...Magnetic Fe304 nanoparticles were synthesized by co-precipitation method and the mercaptopurine (MER) drug-loaded magnetic microspheres were obtained through emulsion cross-linking methods. The efficiency of this approach was evaluated in terms of drug loading content (DLC), encapsulation efficiency (EE) and delivery properties in vitro, determined by high performance liquid chromatograph (HPLC). The microspheres showed good DLC values of 11.8%, as well as good EE values of 79.4%. The in vitro drug release study was carried out in phosphate buffer solution (PBS) simulated body fluid, at 37 ~C with pH=7.4. The release profiles showed an initial fast release rate, which decreased as time progressed and about 84 % had been released after 48 h. The experimental results indicated that the prepared magnetic microspheres may be useful for potential applications of MER for magnetically targeted chemotherapy.展开更多
文摘土壤深层碳库巨大,在全球碳循环中具有重要作用。为了深入理解深层土壤碳循环,分析深层土壤为主题的全球土壤碳循环研究的热点与前沿,以Web of Science核心合集为数据库,获取近25年以深层土壤为主题词的土壤碳循环研究文献(280篇)。通过文献计量方法,分别对年文献发表量、研究区分布、研究主题热点等进行了统计与可视化分析。结果表明:(1)1995-2020年间,以深层土壤为主题词对土壤碳循环研究的发文数量逐渐增长,尤其是2010-2020年期间;(2)不同研究主题对深层土壤的定义不同,其中以土壤碳储量为主题的研究对深层土壤的定义深度最深,52.2%的文献对深层土壤定义深度超过60 cm;(3)农林、环境科学、土壤科学和生态学是深层土壤碳循环研究的主要领域;(4)研究热点主要集中在环境因素和土地利用变化对土壤碳储量、碳稳定性及碳剖面垂直变化的影响方面;(5)近几年,研究主题逐渐向微生物群落、激发效应、碳组分、碳稳定性等转变,研究对象扩展到了北极永久冻土。
基金Funded by the Natural Science Foundation of Hubei Province(No.2011CDA056)the International Cooperation Funding of Hubei Province(No.2012IHA0120)+1 种基金the Fundamental Research Funds for the Central Universities of China(2012-IV-029)the Undergraduate innovation Funding of Wuhan University of Technology(136620004)
文摘Magnetic Fe304 nanoparticles were synthesized by co-precipitation method and the mercaptopurine (MER) drug-loaded magnetic microspheres were obtained through emulsion cross-linking methods. The efficiency of this approach was evaluated in terms of drug loading content (DLC), encapsulation efficiency (EE) and delivery properties in vitro, determined by high performance liquid chromatograph (HPLC). The microspheres showed good DLC values of 11.8%, as well as good EE values of 79.4%. The in vitro drug release study was carried out in phosphate buffer solution (PBS) simulated body fluid, at 37 ~C with pH=7.4. The release profiles showed an initial fast release rate, which decreased as time progressed and about 84 % had been released after 48 h. The experimental results indicated that the prepared magnetic microspheres may be useful for potential applications of MER for magnetically targeted chemotherapy.