灌丛化会改变草本植物的分布格局,影响生态系统结构和功能。为了解“灌丛化”相关领域的发展现状、研究热点及前沿趋势,理清该领域研究的知识结构。本研究依托中国知网数据库(CNKI)及Web of Science(WOS)核心合集数据库,以1982~2023年...灌丛化会改变草本植物的分布格局,影响生态系统结构和功能。为了解“灌丛化”相关领域的发展现状、研究热点及前沿趋势,理清该领域研究的知识结构。本研究依托中国知网数据库(CNKI)及Web of Science(WOS)核心合集数据库,以1982~2023年“灌丛化”相关领域已发表的4114篇文献为数据源,利用VOSviewer和CiteSpace可视化软件对“灌丛化”相关研究领域发文情况(数量、趋势、被引频次)、合作关系(团队、机构、国家)和关键词等进行可视化分析。结果显示:(1)国内国际相关研究总体呈稳步增长趋势,外文研究的热度大于中文研究,且高被引论文均发表在国内外影响力较高的期刊上,表明“灌丛化”相关研究成果在该领域认可度较高,具有较高学术价值;(2)“灌丛化”相关研究国际合作关系(团队、机构、国家)较国内更为密切,且美国、中国、南非、澳大利亚及德国是“灌丛化”相关领域研究的中坚力量。(3)目前“灌丛化”相关领域的研究内容主要包括灌丛化形成机制及生物多样性对灌丛化的响应,草、灌木之间的竞争关系和土壤性质对灌丛化的响应等。研究指出:我国“灌丛化”相关研究尚处于起步阶段,且前人对灌丛化的研究多针对具体研究区域,相对分散,且合作较少;同时在全球尺度上的研究及大数据整合分析相对较少,仍需进一步研究。随着“灌丛化”研究的深入发展,灌丛化对微生物群落组成的影响、灌丛化对干旱胁迫等环境因子的响应及控制灌丛化有效措施等相关研究将在未来一段时间持续热门。展开更多
The quality of beam in the accelerator has a close relationship with the vacuum degree, and the outgassing rateof built-in material have a great effect on vacuum degree[1]. So the outgassing rate of the built-in mater...The quality of beam in the accelerator has a close relationship with the vacuum degree, and the outgassing rateof built-in material have a great effect on vacuum degree[1]. So the outgassing rate of the built-in material shouldbe confirmed and then the influence on the vacuum can be evaluated.Different materials and even the same material in different treatments have different outgassing rate. It couldbe confirmed by vacuum manual or experimental tests. There are two sets of device: one is the traditional orificeconductance method. The other is switching between two pumping paths (SPP), as shown in Fig. 1.展开更多
Based on the technology of DC magnetron sputtering,the Vacuum Technology Group at IMP have developed a large-scale multi-target magnetron sputtering coating device.As shown in Fig.1,it is mainly composed of four parts...Based on the technology of DC magnetron sputtering,the Vacuum Technology Group at IMP have developed a large-scale multi-target magnetron sputtering coating device.As shown in Fig.1,it is mainly composed of four parts,i,e,the coating chamber,the evacuation system,the cooling system and the control system.The coating chamber is installed with compound vacuum gauge and temperature sensor,which can accurately measure the pressure and temperature.展开更多
The pulsed dipole magnets with a eld ramping rate of up to 12 T/s will be used in the Booster Ring(BRing)of High Intensity Heavy Ion Accelerator Facility(HIAF)^([1]).To reduce the eddy current e ect as well as the mag...The pulsed dipole magnets with a eld ramping rate of up to 12 T/s will be used in the Booster Ring(BRing)of High Intensity Heavy Ion Accelerator Facility(HIAF)^([1]).To reduce the eddy current e ect as well as the magnetic hysteresis that results from the rapid ramping of magneticfield,a 0.3 mm stainless steel ceramic-lined thin-wall arc vacuum chamber has been proposed^([2]).展开更多
中国科学院近代物理研究所从历次的大科学装置建设中,积累了大型真空腔体、超高/极高真空系统以及强流重离子加速器真空系统等设计经验。为了获得超高/极高真空系,从真空设备选择、材料处理、密封形式以及在线烘烤等方面形成了一套完整...中国科学院近代物理研究所从历次的大科学装置建设中,积累了大型真空腔体、超高/极高真空系统以及强流重离子加速器真空系统等设计经验。为了获得超高/极高真空系,从真空设备选择、材料处理、密封形式以及在线烘烤等方面形成了一套完整的工艺流程;在强流重离子加速器(High Intensity Heavy ion Accelerator Facility,HIAF)真空系统研制过程中,为了减小磁铁气隙尺寸,大幅度降低磁铁造价及电源运维成本,提出陶瓷内衬薄壁真空室新方法,并研制了原理性样机;为了有效控制HIAF未来运行过程中的动态真空效应,设计了束流准直器,开展了真空材料解吸率测量研究;为了解决高放射性区域真空系统的维护问题,提出了自重密封结构,同时研制了充气膨胀密封法兰;为了进一步优化高精度环形谱仪真空度,开展低温极高真空系统研究。展开更多
文摘灌丛化会改变草本植物的分布格局,影响生态系统结构和功能。为了解“灌丛化”相关领域的发展现状、研究热点及前沿趋势,理清该领域研究的知识结构。本研究依托中国知网数据库(CNKI)及Web of Science(WOS)核心合集数据库,以1982~2023年“灌丛化”相关领域已发表的4114篇文献为数据源,利用VOSviewer和CiteSpace可视化软件对“灌丛化”相关研究领域发文情况(数量、趋势、被引频次)、合作关系(团队、机构、国家)和关键词等进行可视化分析。结果显示:(1)国内国际相关研究总体呈稳步增长趋势,外文研究的热度大于中文研究,且高被引论文均发表在国内外影响力较高的期刊上,表明“灌丛化”相关研究成果在该领域认可度较高,具有较高学术价值;(2)“灌丛化”相关研究国际合作关系(团队、机构、国家)较国内更为密切,且美国、中国、南非、澳大利亚及德国是“灌丛化”相关领域研究的中坚力量。(3)目前“灌丛化”相关领域的研究内容主要包括灌丛化形成机制及生物多样性对灌丛化的响应,草、灌木之间的竞争关系和土壤性质对灌丛化的响应等。研究指出:我国“灌丛化”相关研究尚处于起步阶段,且前人对灌丛化的研究多针对具体研究区域,相对分散,且合作较少;同时在全球尺度上的研究及大数据整合分析相对较少,仍需进一步研究。随着“灌丛化”研究的深入发展,灌丛化对微生物群落组成的影响、灌丛化对干旱胁迫等环境因子的响应及控制灌丛化有效措施等相关研究将在未来一段时间持续热门。
文摘The quality of beam in the accelerator has a close relationship with the vacuum degree, and the outgassing rateof built-in material have a great effect on vacuum degree[1]. So the outgassing rate of the built-in material shouldbe confirmed and then the influence on the vacuum can be evaluated.Different materials and even the same material in different treatments have different outgassing rate. It couldbe confirmed by vacuum manual or experimental tests. There are two sets of device: one is the traditional orificeconductance method. The other is switching between two pumping paths (SPP), as shown in Fig. 1.
文摘Based on the technology of DC magnetron sputtering,the Vacuum Technology Group at IMP have developed a large-scale multi-target magnetron sputtering coating device.As shown in Fig.1,it is mainly composed of four parts,i,e,the coating chamber,the evacuation system,the cooling system and the control system.The coating chamber is installed with compound vacuum gauge and temperature sensor,which can accurately measure the pressure and temperature.
文摘The pulsed dipole magnets with a eld ramping rate of up to 12 T/s will be used in the Booster Ring(BRing)of High Intensity Heavy Ion Accelerator Facility(HIAF)^([1]).To reduce the eddy current e ect as well as the magnetic hysteresis that results from the rapid ramping of magneticfield,a 0.3 mm stainless steel ceramic-lined thin-wall arc vacuum chamber has been proposed^([2]).
文摘中国科学院近代物理研究所从历次的大科学装置建设中,积累了大型真空腔体、超高/极高真空系统以及强流重离子加速器真空系统等设计经验。为了获得超高/极高真空系,从真空设备选择、材料处理、密封形式以及在线烘烤等方面形成了一套完整的工艺流程;在强流重离子加速器(High Intensity Heavy ion Accelerator Facility,HIAF)真空系统研制过程中,为了减小磁铁气隙尺寸,大幅度降低磁铁造价及电源运维成本,提出陶瓷内衬薄壁真空室新方法,并研制了原理性样机;为了有效控制HIAF未来运行过程中的动态真空效应,设计了束流准直器,开展了真空材料解吸率测量研究;为了解决高放射性区域真空系统的维护问题,提出了自重密封结构,同时研制了充气膨胀密封法兰;为了进一步优化高精度环形谱仪真空度,开展低温极高真空系统研究。
