A theoretical study of the influence of a quasi-electrostatic support on the amplification level of the slow space charge wave(SCW) in the amplification section of a superheterodyne free electron laser(FEL) was carrie...A theoretical study of the influence of a quasi-electrostatic support on the amplification level of the slow space charge wave(SCW) in the amplification section of a superheterodyne free electron laser(FEL) was carried out. One of the ways to significantly increase the saturation level of the slow SCW is maintaining the conditions of a three-wave parametric resonance between the slow, fast SCWs and the resulting pump electric field. This can be done by introducing the quasielectrostatic support in the superheterodyne FEL amplification section. Also, it was found that the generated pump electric field significantly influences the maintenance of parametric resonance conditions. As a result, this increases the saturation level of the slow SCW by 70%. Finally, the quasi-electrostatic support significantly reduces the maximum value of the electrostatic undulator pump field strength, which is necessary to achieve the maximum saturation level of the slow SCW.展开更多
Permanently shadowed regions(PSRs)on the Moon are potential reservoirs for water ice,making them hot spots for future lunar exploration.The water ice in PSRs would cause distinctive changes in space weathering there,i...Permanently shadowed regions(PSRs)on the Moon are potential reservoirs for water ice,making them hot spots for future lunar exploration.The water ice in PSRs would cause distinctive changes in space weathering there,in particular reduction-oxidation processes that diff er from those in illuminated regions.To determine the characteris-tics of products formed during space weathering in PSRs,the lunar meteorite NWA 10203 with artifi cially added water was irradiated with a nanosecond laser to simulate a micro-meteorite bombardment of lunar soil containing water ice.The TEM results of the water-incorporated sample showed distinct amorphous rims that exhibited irregular thickness,poor stratifi cation,the appearance of bubbles,and a reduced number of npFe^(0).Additionally,EELS analysis showed the presence of ferric iron at the rim of the nanophase metallic iron particles(npFe^(0))in the amorphous rim with the involve-ment of water.The results suggest that water ice is another possible factor contributing to oxidation during microme-teorite bombardment on the lunar surface.In addition,it off ers a reference for a new space weathering model that incorporates water in PSRs,which could be widespread on asteroids with volatiles.展开更多
Flexible surface micro-discharge plasma is a non-thermal plasma technique used for treating wounds in a painless way, with significant efficacy for chronic or hard-to-heal wounds. In this study, a confined space was d...Flexible surface micro-discharge plasma is a non-thermal plasma technique used for treating wounds in a painless way, with significant efficacy for chronic or hard-to-heal wounds. In this study, a confined space was designed to simulate wound conditions, with gelatin used to simulate wound tissue. The distinction between open and confined spaces was explored, and the effects of temperature, humidity, discharge power and the gap size within the confined space on the plasma characteristics were analyzed. It was found that temperature, humidity and discharge power are important factors that affect the concentration distribution of active components and the mode transition between ozone and nitrogen oxides. Compared to open space, the concentration of ozone in confined space was relatively lower, which facilitated the formation of nitrogen oxides. In open space, the discharge was dominated by ozone initially. As the temperature,humidity and discharge power increased, nitrogen oxides in the gas-phase products were gradually detected. In confined space, nitrogen oxides can be detected at an early stage and at much higher concentrations than ozone concentration. Furthermore, as the gap of the confined space decreased, the concentration of ozone was observed to decrease while that of nitrate increased, and the rate of this concentration change was further accelerated at higher temperature and higher power. It was shown that ozone concentration decreased from 0.11 to 0.03 μmol and the nitrate concentration increased from 20.5 to 24.5 μmol when the spacing in the confined space was reduced from 5 to 1 mm, the temperature of the external discharge was controlled at 40 ℃, and the discharge power was 12 W. In summary, this study reveals the formation and transformation mechanisms of active substances in air surface micro-discharge plasma within confined space, providing foundational data for its medical applications.展开更多
目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,...目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。展开更多
螺旋藻(Spirulina)藻蓝蛋白具有独特的理化特性及生理功能,是药物、食品和化妆品的天然原料,具有较大的开发潜力。为探讨螺旋藻藻蓝蛋白的研究现状与发展前景,对中国知网和Web of Science数据库中1990—2023年发表的文献进行检索并筛选...螺旋藻(Spirulina)藻蓝蛋白具有独特的理化特性及生理功能,是药物、食品和化妆品的天然原料,具有较大的开发潜力。为探讨螺旋藻藻蓝蛋白的研究现状与发展前景,对中国知网和Web of Science数据库中1990—2023年发表的文献进行检索并筛选,使用Cite Space软件对文章发文量、研究团队及研究热点进行图谱分析。综合分析可知,国内年发文量偏少,呈平稳趋势;国外年发文量持续上升,尤其近几年发文量迅速增长,且发文量超过了100篇;国外研究热点集中于藻蓝蛋白在食品、医药行业的应用方面,而国内研究热点集中在提取纯化、稳定性、功能活性的研究与应用,下一步应结合研究现状开发适合规模化生产的提取纯化工艺,进一步加强藻蓝蛋白研究的广度与深度;国内外研究群体主要是高校的相关生物技术学院或研究机构等,总体来讲,学者间存在较为密切的合作,但研究机构间尚未形成紧密的合作关系,在地域上比较分散,各大高校和研究机构应突破地区或机构间的各种限制,促进该研究领域的深度融合和快速发展,深入挖掘藻蓝蛋白在各个领域的潜在应用。展开更多
目的梳理国内多发伤急救相关研究文献,分析研究现状、热点和趋势,为我国多发伤急救研究提供借鉴和指导。方法检索中国知网数据库中2011—2021年关于多发伤急救的相关文献,使用Cite Space 6.1.R3可视化软件对该领域的年发文量、机构、作...目的梳理国内多发伤急救相关研究文献,分析研究现状、热点和趋势,为我国多发伤急救研究提供借鉴和指导。方法检索中国知网数据库中2011—2021年关于多发伤急救的相关文献,使用Cite Space 6.1.R3可视化软件对该领域的年发文量、机构、作者、关键词进行分析。结果最终纳入多发伤急救研究文献2519篇,整体发文数量较平稳,以2016年为小高峰;发文量最高的机构是华中科技大学附属同济医院。多发伤急救研究热点包括院前急救、并发症护理、风险因素分析和预后效果评估,研究前沿包括不同多发伤人群的诊断、治疗、手术和护理体会等方面。结论本文通过可视化分析国内多发伤急救研究的热点及趋势,指明了多发伤目前研究存在的问题和未来研究发展的方向,为进一步完善多发伤急救卫生服务和管理体系提供指导。展开更多
为了解国内外近10年护理不良事件的研究热点与前沿,为医院管理和临床护士提供参考,保障患者安全,通过检索中国期刊全文数据库(CNKI)和Web of Science(WOS)数据库,检索时限为2012年1月—2022年8月,导入CiteSpace进行可视化分析。研究显示...为了解国内外近10年护理不良事件的研究热点与前沿,为医院管理和临床护士提供参考,保障患者安全,通过检索中国期刊全文数据库(CNKI)和Web of Science(WOS)数据库,检索时限为2012年1月—2022年8月,导入CiteSpace进行可视化分析。研究显示,从发文量看,国内外学者对护理不良事件的关注度整体较高,可视化分析结果并未发现作者之间、机构之间的联系。未来减少护理不良事件的方法一定会越来越紧贴科学技术,越来越多的新型信息化平台、App等会用于医疗行业,降低护理不良事件预防的难度,但护理人员仍要重视护理安全。展开更多
Since 2011,the Chinese Academy of Sciences(CAS)has implemented the Strategic Priority Program on Space Science(SPP).A series of scientific satellites have been developed and launched,such as Dark Matter Particle Explo...Since 2011,the Chinese Academy of Sciences(CAS)has implemented the Strategic Priority Program on Space Science(SPP).A series of scientific satellites have been developed and launched,such as Dark Matter Particle Explorer(DAMPE),Quantum Experiments at Space Scale(QUESS),Advanced Space-based Solar Observatory(ASO-S),Einstein Probe(EP),and significant scientific outcomes have been achieved.In order to plan the future space science missions in China,CAS has organized the Chinese space science community to conduct medium and long-term development strategy studies,and summarized the major scientific frontiers of space science as“One Black,Two Dark,Three Origins and Five Characterizations”.Five main scientific themes have been identified for China’s future breakthroughs,including the Extreme Universe,Space-Time Ripples,the Panoramic View of the Sun and Earth,the Habitable Planets,and Biological&Physical Science in Space.Space science satellite missions to be implemented before 2030 are proposed accordingly.展开更多
文摘A theoretical study of the influence of a quasi-electrostatic support on the amplification level of the slow space charge wave(SCW) in the amplification section of a superheterodyne free electron laser(FEL) was carried out. One of the ways to significantly increase the saturation level of the slow SCW is maintaining the conditions of a three-wave parametric resonance between the slow, fast SCWs and the resulting pump electric field. This can be done by introducing the quasielectrostatic support in the superheterodyne FEL amplification section. Also, it was found that the generated pump electric field significantly influences the maintenance of parametric resonance conditions. As a result, this increases the saturation level of the slow SCW by 70%. Finally, the quasi-electrostatic support significantly reduces the maximum value of the electrostatic undulator pump field strength, which is necessary to achieve the maximum saturation level of the slow SCW.
基金support from the Youth Innovation Promotion Association,Chinese Academy of Sciences(2020395)Strategic Priority Research Program of the Chinese Academy of Sciences grant XDB 41000000(Y.L.)+4 种基金National Natural Science Foundation of China(Nos.42273042 and 41931077)"From 0 to 1"Original Exploration Cultivation Project,Institute of Geochemistry,Chinese Academy of Sciences(DHSZZ2023-3)Guizhou Provincial Foundation for Excellent Scholars Program(No.GCC[2023]088)Guizhou Provincial Science and Technology Projects:QKHJCZK[2023]-General 473NSFC Young Scientist Fund(Nos.42303041 and 42403043)。
文摘Permanently shadowed regions(PSRs)on the Moon are potential reservoirs for water ice,making them hot spots for future lunar exploration.The water ice in PSRs would cause distinctive changes in space weathering there,in particular reduction-oxidation processes that diff er from those in illuminated regions.To determine the characteris-tics of products formed during space weathering in PSRs,the lunar meteorite NWA 10203 with artifi cially added water was irradiated with a nanosecond laser to simulate a micro-meteorite bombardment of lunar soil containing water ice.The TEM results of the water-incorporated sample showed distinct amorphous rims that exhibited irregular thickness,poor stratifi cation,the appearance of bubbles,and a reduced number of npFe^(0).Additionally,EELS analysis showed the presence of ferric iron at the rim of the nanophase metallic iron particles(npFe^(0))in the amorphous rim with the involve-ment of water.The results suggest that water ice is another possible factor contributing to oxidation during microme-teorite bombardment on the lunar surface.In addition,it off ers a reference for a new space weathering model that incorporates water in PSRs,which could be widespread on asteroids with volatiles.
基金supported by Postgraduate Research&Practice Innovation Program of Jiangsu Province (No. 1003016001)。
文摘Flexible surface micro-discharge plasma is a non-thermal plasma technique used for treating wounds in a painless way, with significant efficacy for chronic or hard-to-heal wounds. In this study, a confined space was designed to simulate wound conditions, with gelatin used to simulate wound tissue. The distinction between open and confined spaces was explored, and the effects of temperature, humidity, discharge power and the gap size within the confined space on the plasma characteristics were analyzed. It was found that temperature, humidity and discharge power are important factors that affect the concentration distribution of active components and the mode transition between ozone and nitrogen oxides. Compared to open space, the concentration of ozone in confined space was relatively lower, which facilitated the formation of nitrogen oxides. In open space, the discharge was dominated by ozone initially. As the temperature,humidity and discharge power increased, nitrogen oxides in the gas-phase products were gradually detected. In confined space, nitrogen oxides can be detected at an early stage and at much higher concentrations than ozone concentration. Furthermore, as the gap of the confined space decreased, the concentration of ozone was observed to decrease while that of nitrate increased, and the rate of this concentration change was further accelerated at higher temperature and higher power. It was shown that ozone concentration decreased from 0.11 to 0.03 μmol and the nitrate concentration increased from 20.5 to 24.5 μmol when the spacing in the confined space was reduced from 5 to 1 mm, the temperature of the external discharge was controlled at 40 ℃, and the discharge power was 12 W. In summary, this study reveals the formation and transformation mechanisms of active substances in air surface micro-discharge plasma within confined space, providing foundational data for its medical applications.
文摘目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。
文摘螺旋藻(Spirulina)藻蓝蛋白具有独特的理化特性及生理功能,是药物、食品和化妆品的天然原料,具有较大的开发潜力。为探讨螺旋藻藻蓝蛋白的研究现状与发展前景,对中国知网和Web of Science数据库中1990—2023年发表的文献进行检索并筛选,使用Cite Space软件对文章发文量、研究团队及研究热点进行图谱分析。综合分析可知,国内年发文量偏少,呈平稳趋势;国外年发文量持续上升,尤其近几年发文量迅速增长,且发文量超过了100篇;国外研究热点集中于藻蓝蛋白在食品、医药行业的应用方面,而国内研究热点集中在提取纯化、稳定性、功能活性的研究与应用,下一步应结合研究现状开发适合规模化生产的提取纯化工艺,进一步加强藻蓝蛋白研究的广度与深度;国内外研究群体主要是高校的相关生物技术学院或研究机构等,总体来讲,学者间存在较为密切的合作,但研究机构间尚未形成紧密的合作关系,在地域上比较分散,各大高校和研究机构应突破地区或机构间的各种限制,促进该研究领域的深度融合和快速发展,深入挖掘藻蓝蛋白在各个领域的潜在应用。
文摘目的梳理国内多发伤急救相关研究文献,分析研究现状、热点和趋势,为我国多发伤急救研究提供借鉴和指导。方法检索中国知网数据库中2011—2021年关于多发伤急救的相关文献,使用Cite Space 6.1.R3可视化软件对该领域的年发文量、机构、作者、关键词进行分析。结果最终纳入多发伤急救研究文献2519篇,整体发文数量较平稳,以2016年为小高峰;发文量最高的机构是华中科技大学附属同济医院。多发伤急救研究热点包括院前急救、并发症护理、风险因素分析和预后效果评估,研究前沿包括不同多发伤人群的诊断、治疗、手术和护理体会等方面。结论本文通过可视化分析国内多发伤急救研究的热点及趋势,指明了多发伤目前研究存在的问题和未来研究发展的方向,为进一步完善多发伤急救卫生服务和管理体系提供指导。
文摘为了解国内外近10年护理不良事件的研究热点与前沿,为医院管理和临床护士提供参考,保障患者安全,通过检索中国期刊全文数据库(CNKI)和Web of Science(WOS)数据库,检索时限为2012年1月—2022年8月,导入CiteSpace进行可视化分析。研究显示,从发文量看,国内外学者对护理不良事件的关注度整体较高,可视化分析结果并未发现作者之间、机构之间的联系。未来减少护理不良事件的方法一定会越来越紧贴科学技术,越来越多的新型信息化平台、App等会用于医疗行业,降低护理不良事件预防的难度,但护理人员仍要重视护理安全。
基金Supported by Consultation and Evaluation Program on Academic Divisions of the Chinese Academy of Sciences(2022-DX02-B-007)。
文摘Since 2011,the Chinese Academy of Sciences(CAS)has implemented the Strategic Priority Program on Space Science(SPP).A series of scientific satellites have been developed and launched,such as Dark Matter Particle Explorer(DAMPE),Quantum Experiments at Space Scale(QUESS),Advanced Space-based Solar Observatory(ASO-S),Einstein Probe(EP),and significant scientific outcomes have been achieved.In order to plan the future space science missions in China,CAS has organized the Chinese space science community to conduct medium and long-term development strategy studies,and summarized the major scientific frontiers of space science as“One Black,Two Dark,Three Origins and Five Characterizations”.Five main scientific themes have been identified for China’s future breakthroughs,including the Extreme Universe,Space-Time Ripples,the Panoramic View of the Sun and Earth,the Habitable Planets,and Biological&Physical Science in Space.Space science satellite missions to be implemented before 2030 are proposed accordingly.
