东北黑土地是我国粮食生产的“稳定器”和“压舱石”。严重的水土流失导致黑土层变薄、耕地损毁及地力下降,威胁我国粮食安全。本文以CNKI数据库中662篇东北黑土区土壤侵蚀领域研究中文文献和Web of Science核心数据库中189篇英文文献...东北黑土地是我国粮食生产的“稳定器”和“压舱石”。严重的水土流失导致黑土层变薄、耕地损毁及地力下降,威胁我国粮食安全。本文以CNKI数据库中662篇东北黑土区土壤侵蚀领域研究中文文献和Web of Science核心数据库中189篇英文文献为对象,利用文献计量方法,借助CiteSpace和VOSviewer绘制东北黑土区土壤侵蚀知识图谱,识别主要载文期刊、资金来源、核心作者及团队,梳理不同时期研究热点和发展趋势,揭示其背后的影响因素。结果显示:①该主题中文发文量自2003年快速增长,2003−2021年载文量占总量91.6%,载文前3的期刊是《农业工程学报》《土壤学报》《农业机械学报》。英文文献起步较晚,载文前3的期刊是Soil and Tillage Research、Catena和Geoderma。已发表的中、英文文献研究经费主要来源于国家自然科学基金。②该领域较早开展研究的是以张晓平为代表的中国科学院东北地理与农业生态研究所团队和以蔡强国为代表的中国科学院地理科学与资源研究所团队,中文文献发文量前3的学者是郑粉莉、韩晓增和张兴义,英文文献发文量前3的学者是张兴义、刘晓冰和刘刚。③“土壤水蚀过程与机理”“土壤侵蚀时空变化评价”“土壤退化与保护性耕作”“水土保持与土地生产力”“侵蚀沟发育与耕地保护”“土壤侵蚀与土壤质量”“土壤侵蚀速率”“风力和冻融对水力侵蚀的影响”是不同时期的研究热点。④“人工模拟降雨”“GIS和RS”“土壤侵蚀模型”“137Cs和210Pb示踪法”是主要研究方法和手段。复合侵蚀过程及机理,区域土壤侵蚀预测模型研发,水土流失阻控措施及效应,土壤侵蚀退化与土地生产力的关系等是未来研究的重点。展开更多
The reassembly of a half-sequence ionic self-complementarity peptide CH3CO-Pro-Ser-Phe- Cys-Phe-Lys-Phe-Glu-Pro-NH2 was reported, which could self-assemble into stable nanofibers, and formed hydrogel consisting of 〉9...The reassembly of a half-sequence ionic self-complementarity peptide CH3CO-Pro-Ser-Phe- Cys-Phe-Lys-Phe-Glu-Pro-NH2 was reported, which could self-assemble into stable nanofibers, and formed hydrogel consisting of 〉99% water. In this study, the nanofiber scaffold was sonicated by an ultrasonic cell disruptor. The effects of sonication were detected by circular dichroism （CD）, atomic force microscopy （AFM）, and rheology. AFM image illustrated that the sonicated fragments could quickly reassemble into nanofibers, while the morphology was distinguishable from the original one. CD spectrum revealed that the conversion occurred mainly between regular β-strand structure and distorted β-strand structure. Rheological analyses showed that the storage modulus （G＇） of the peptide solution at the 7th day after sonication decreased by nearly 40% compared with the value of the solution before sonication. Finally, a plausible conversion model was proposed to interpret the reassembly process.展开更多
文摘东北黑土地是我国粮食生产的“稳定器”和“压舱石”。严重的水土流失导致黑土层变薄、耕地损毁及地力下降,威胁我国粮食安全。本文以CNKI数据库中662篇东北黑土区土壤侵蚀领域研究中文文献和Web of Science核心数据库中189篇英文文献为对象,利用文献计量方法,借助CiteSpace和VOSviewer绘制东北黑土区土壤侵蚀知识图谱,识别主要载文期刊、资金来源、核心作者及团队,梳理不同时期研究热点和发展趋势,揭示其背后的影响因素。结果显示:①该主题中文发文量自2003年快速增长,2003−2021年载文量占总量91.6%,载文前3的期刊是《农业工程学报》《土壤学报》《农业机械学报》。英文文献起步较晚,载文前3的期刊是Soil and Tillage Research、Catena和Geoderma。已发表的中、英文文献研究经费主要来源于国家自然科学基金。②该领域较早开展研究的是以张晓平为代表的中国科学院东北地理与农业生态研究所团队和以蔡强国为代表的中国科学院地理科学与资源研究所团队,中文文献发文量前3的学者是郑粉莉、韩晓增和张兴义,英文文献发文量前3的学者是张兴义、刘晓冰和刘刚。③“土壤水蚀过程与机理”“土壤侵蚀时空变化评价”“土壤退化与保护性耕作”“水土保持与土地生产力”“侵蚀沟发育与耕地保护”“土壤侵蚀与土壤质量”“土壤侵蚀速率”“风力和冻融对水力侵蚀的影响”是不同时期的研究热点。④“人工模拟降雨”“GIS和RS”“土壤侵蚀模型”“137Cs和210Pb示踪法”是主要研究方法和手段。复合侵蚀过程及机理,区域土壤侵蚀预测模型研发,水土流失阻控措施及效应,土壤侵蚀退化与土地生产力的关系等是未来研究的重点。
基金Funded by the National Natural Science Foundation of China(No.51003065)New Teachers'Fund for Doctor Stations,Ministry of Education(No.20100181120077)
文摘The reassembly of a half-sequence ionic self-complementarity peptide CH3CO-Pro-Ser-Phe- Cys-Phe-Lys-Phe-Glu-Pro-NH2 was reported, which could self-assemble into stable nanofibers, and formed hydrogel consisting of 〉99% water. In this study, the nanofiber scaffold was sonicated by an ultrasonic cell disruptor. The effects of sonication were detected by circular dichroism （CD）, atomic force microscopy （AFM）, and rheology. AFM image illustrated that the sonicated fragments could quickly reassemble into nanofibers, while the morphology was distinguishable from the original one. CD spectrum revealed that the conversion occurred mainly between regular β-strand structure and distorted β-strand structure. Rheological analyses showed that the storage modulus （G＇） of the peptide solution at the 7th day after sonication decreased by nearly 40% compared with the value of the solution before sonication. Finally, a plausible conversion model was proposed to interpret the reassembly process.
