By two direct assumption methods and symbolic computation,we present two families of one-soliton solutions and a family of two-soliton solutions with some arbitrary functions for the three-dimensional Gross–Pitaevski...By two direct assumption methods and symbolic computation,we present two families of one-soliton solutions and a family of two-soliton solutions with some arbitrary functions for the three-dimensional Gross–Pitaevskii equation with time-space modulation.Then we investigate the dynamics of these matter-wave solitons in three-dimensional Bose–Einstein condensates.We can see that the intensities of both one-solitons and two-solitons first increase rapidly to the condensation peak value,then decay very slowly to the background value.Thus these matter-wave solitons in three-dimensional Bose–Einstein condensates can remain for a sufficiently long time to be fully observed and modulated for real applications in today's experiments.展开更多
农业保险具有风险管理及收入支持的功能,作为国家农业风险管理体系的重要组成部分,将逐步影响农业生产的各环节。为深入了解农业保险研究进展,利用CiteSpace和VosViewer这2种文献计量工具对中国知网和Web of Science数据库中2002—2022...农业保险具有风险管理及收入支持的功能,作为国家农业风险管理体系的重要组成部分,将逐步影响农业生产的各环节。为深入了解农业保险研究进展,利用CiteSpace和VosViewer这2种文献计量工具对中国知网和Web of Science数据库中2002—2022年的农业保险研究文献进行可视化分析。结果表明:国际农业保险研究呈现逐年上升趋势,美国处于该领域研究的前沿;根据发文量、作者、机构等内容,美国、德国农业保险研究实力较强,中国在全球发文量排第3位,瑞士学者Finger Robert的发文量最多;美国康奈尔大学在发文量、总连接强度、被引用文献次数中均位列前3位,中国农业大学和华中农业大学在国内具有较强研究实力;国内外均未形成稳定作者合作群体;根据研究内容,我国农业保险研究主要集中在金融、保险、宏观经济管理与可持续发展、农业基础科学等方向;研究热点分析表明,世界农业保险研究热点包括气候变化、道德风险、指数保险等,中国农业保险研究热点包括农村金融、保费补贴、乡村振兴等。展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11041003the Ningbo Natural Science Foundation under Grant No 2009B21003the K.C.Wong Magna Fund in Ningbo University.
文摘By two direct assumption methods and symbolic computation,we present two families of one-soliton solutions and a family of two-soliton solutions with some arbitrary functions for the three-dimensional Gross–Pitaevskii equation with time-space modulation.Then we investigate the dynamics of these matter-wave solitons in three-dimensional Bose–Einstein condensates.We can see that the intensities of both one-solitons and two-solitons first increase rapidly to the condensation peak value,then decay very slowly to the background value.Thus these matter-wave solitons in three-dimensional Bose–Einstein condensates can remain for a sufficiently long time to be fully observed and modulated for real applications in today's experiments.
文摘农业保险具有风险管理及收入支持的功能,作为国家农业风险管理体系的重要组成部分,将逐步影响农业生产的各环节。为深入了解农业保险研究进展,利用CiteSpace和VosViewer这2种文献计量工具对中国知网和Web of Science数据库中2002—2022年的农业保险研究文献进行可视化分析。结果表明:国际农业保险研究呈现逐年上升趋势,美国处于该领域研究的前沿;根据发文量、作者、机构等内容,美国、德国农业保险研究实力较强,中国在全球发文量排第3位,瑞士学者Finger Robert的发文量最多;美国康奈尔大学在发文量、总连接强度、被引用文献次数中均位列前3位,中国农业大学和华中农业大学在国内具有较强研究实力;国内外均未形成稳定作者合作群体;根据研究内容,我国农业保险研究主要集中在金融、保险、宏观经济管理与可持续发展、农业基础科学等方向;研究热点分析表明,世界农业保险研究热点包括气候变化、道德风险、指数保险等,中国农业保险研究热点包括农村金融、保费补贴、乡村振兴等。