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High sulfur loading and shuttle inhibition of advanced sulfur cathode enabled by graphene network skin and N,P,F-doped mesoporous carbon interfaces for ultra-stable lithium sulfur battery

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Nano Research Energy 2023年第1期2卷 148-156页

作者： Haotian Liu Fan Liu Zehua Qu Jieling Chen Hui Liu Yiqing Tan Jiabao Guo Yan Yan Shuang zhao xinsheng zhao Xinming Nie Xin Ma Zengxia Pei Mingkai Liu School of Chemistry&Materials Science Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional MaterialsJiangsu Normal UniversityXuzhou 221116China School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200433China School of Physics and Electronic Engineering Jiangsu Normal UniversityXuzhou 221116China School of Chemistry and Materials Science Nanjing University of Information Science and TechnologyNanjing 210044China School of Chemical and Biomolecular Engineering The University of SydneySydneyNew South Wales 2006Australia

Achieving high loading of active sulfur yet rational regulating the shuttle effect of lithium polysulfide(LiPS)is of great significance in pursuit of high-performance lithium-sulfur(Li-S)battery.Herein,we develop a free-standing graphene nitrogen(N),phosphorus(P)and fluorine(F)co-doped mesoporous carbon-sulfur(G-NPFMC-S)film,which was used as a binder-free cathode in Li-S battery.The developed mesoporous carbon(MC)achieved a high specific surface area of 921 m^(2)·g^(-1)with a uniform pore size distribution of 15 nm.The inserted graphene network inside G-NPFMC-S cathode can effectively improve its electrical conductivity and simultaneously restrict the shuttle of LiPS.A high sulfur loading of 86%was achieved due to the excellent porous structures of graphene-NPFMC(G-NPFMC)composite.When implemented as a freestanding cathode in Li-S battery,this G-NPFMC-S achieved a high specific capacity(1,356 mAh·g^(-1)),favorable rate capability,and long-term cycling stability up to 500 cycles with a minimum capacity fading rate of 0.025%per cycle,outperforming the corresponding performances of NPFMC-sulfur(NPFMC-S)and MC-sulfur(MC-S).These promising results can be ascribed to the featured structures that formed inside G-NPFMC-S film,as that highly porous NPFMC can provide sufficient storage space for the loading of sulfur,while,the N,P,F-doped carbonic interface and the inserted graphene network help hinder the shuttle of LiPS via chemical adsorption and physical barrier effect.This proposed unique structure can provide a bright prospect in that high mass loading of active sulfur and restriction the shuttle of LiPS can be simultaneously achieved for Li-S battery.

关键词： lithium sulfur battery high sulfur loading shuttle inhibition heteroatoms doped interface graphene network barrier

A hybrid carbon aerogel with both aligned and interconnected pores as interlayer for high-performance lithium-sulfur batteries

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Nano Research 2016年第12期9卷 3735-3746页

作者： Mingkai Liu Zhibin Yang Hao Sun Chao Lai xinsheng zhao Huisheng Peng Tianxi Liu School of Chemistry and Chemical Engineering Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials Jiangsu Normal University Xuzhou 221116 China State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science and Laboratory of Advanced Materials Fudan University Shanghai 200438 China School of Physics and Electronic Engineering Jiangsu Normal University Xuzhou 221116 China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University Shanghai 201620 China

The soluble nature of polysulfide species created on the sulfur electrode has severely hampered the electrochemical performance of lithium-sulfur （Li-S） batteries. Trapping and anchoring polysulfides are promising approaches for overcoming this issue. In this work, a mechanically robust, electrically conductive hybrid carbon aerogel （HCA） with aligned and interconnected pores was created and investigated as an interlayer for Li-S batteries. The hierarchical cross-linked networks constructed by graphene sheets and carbon nanotubes can act as an ＂internet＂ to capture the polysulfide, while the micro- and nano-pores inside the aerogel can facilitate quick penetration of the electrolyte and rapid transport of lithium ions. As advantages of the unique structure and excellent accommodation of the volume change of the active materials, a high specific capacity of 1,309 mAh.g-1 at 0.2 C was achieved for the assembled Li-S battery, coupled with good rate performance and long-term cycling stability （78% capacity retention after 600 cycles at 4 C）.

关键词： lithium-sulfur battery carbon aerogel interlayer aligned and interconnectedpores trapped polysulfide

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珞珈三号01星视频智能插帧应用研究

武汉大学学报（信息科学版） 2024年第6期49卷 911-922页

作者：王新晟王密潘俊肖晶李路张昊楠赵简平武汉大学测绘遥感信息工程国家重点实验室湖北武汉430079 武汉大学计算机学院湖北武汉430072 武汉大学网络安全学院湖北武汉430079

光学视频卫星获取的高动态、高空间分辨率的数据为对地动态观测提供了新的技术手段。2023年初发射的珞珈三号01星是新一代智能测绘遥感科学试验卫星,该星可通过凝视成像模式获取对地高清彩色视频,但原始视频帧率较低,仅为6帧/s。为进一... 详细信息

光学视频卫星获取的高动态、高空间分辨率的数据为对地动态观测提供了新的技术手段。2023年初发射的珞珈三号01星是新一代智能测绘遥感科学试验卫星,该星可通过凝视成像模式获取对地高清彩色视频,但原始视频帧率较低,仅为6帧/s。为进一步提升珞珈三号01星视频的流畅度,降低视觉观感的卡顿效果,开展了面向珞珈三号01星视频插帧的相关研究。首先,针对卫星凝视成像过程中的误差进行了分析,提出了一种基于帧间透视变换模型的视频稳像方法,实现了原始视频数据的预处理;然后,考虑到日常可见光视频与卫星视频之间存在较大差异,且目前暂无可用的卫星视频插帧数据集,基于预处理后的稳像视频构建了一个涵盖不同场景的卫星插帧数据集Luojia3_VFISet;最后,基于无需光流模块参与的FLAVR(flow-agnostic video representation)视频插帧网络,通过将不同尺度的特征编码信息引入解码过程,提出了FLAVR_Plus视频插帧网络,进一步提升了卫星视频的插帧效果。实验结果表明,FLAVR_Plus插帧结果的测量峰值信噪比达到35.5446 dB,精度提升约0.5%~7.2%,结构相似性可达0.9179,同比提升约0.5%~8.7%。所构建的Luojia3_VFISet数据集有助于相关研究工作的开展,提出的FLAVR_Plus视频插帧网络针对不同场景均能生成质量良好、无明显拖影的中间帧,可有效提升珞珈三号01星视频的流畅度,为后续的卫星视频相关应用提供更多的帧间信息。

关键词：珞珈三号01星凝视序列影像视频稳像插帧数据集视频插帧

Effect of mangrove restoration on crab burrow density in Luoyangjiang Estuary,China

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Forest Ecosystems 2015年第4期2卷 263-271页

作者： Wei Li Lijuan Cui Manyin Zhang Yifei Wang Yaqiong Zhang Yinru Lei xinsheng zhao Beijing Key Laboratory of Wetland Services and Restoration Institute of Wetland ResearchChinese Academy of Forestry

Background： Mangrove restoration seeks to restore or rebuild degraded mangrove systems. The methods of mangrove restoration include ecological projects and restoration-oriented technologies, the latter of which are designed to restore the structure, processes as well as related physical, chemical and biological characteristics of wetlands and to ensure the provision of ecosystem services. As important components of mangrove ecosystem, benthic organisms and crabs play a key role in nutrient cycling. In addition, mangrove restoration, such as vegetation restoration measures, can lead to changes in the benthic faunal communities. This study investigates whether the presence of different mangrove species, age and canopy cover of mangrove communities affect the density of crab burrows. Methods： The Luoyangjiang Estuary, in the southeast of Fujian Province, was selected as our research area. A survey, covering 14 sites, was conducted to investigate the impacts of mangrove restoration on the density of crab burrows in four rehabilitated forests with different stand ages and canopy. Results： It was found that differences in vegetation types had a large impact on crab density and that the density of crab burrows was lower on exposed beaches （non-mangrove） than under mature Kondelio condel, Aegiceros corniculatum and Avicennio morina communities. In general, the amount of leaf litter and debris on mangrove mudfiats was greater than on the beaches as food sources for crabs. Two-factor analysis of variance （ANOVA） shows that changes in mangrove species and age since restoration had different effects on crab burrow density. The effect of canopy cover was highly significant on crab burrow density. Conclusions： The results suggest that in the process of mangrove restoration the combined effects of mangrove stand age, canopy cover and other factors should be taken into account. This study further supports the findings of the future scientific research and practice on mangrove restoration and management measures.

关键词： Canopy Crab burrow density Mangrove Restoration

Overpotential-dependent shape evolution of gold nanocrystals grown in a deep eutectic solvent

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Nano Research 2016年第11期9卷 3547-3557页

作者： Lu Wei Bangan Lu Mingjun Sun Na Tian Zhiyou Zhou Binbin Xu xinsheng zhao Shigang Sun School of Physics and Electronic Engineering Jiangsu Normal University Xuzhou 221116 China College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China

This paper reports an overpotential-dependent shape evolution of gold nano-crystals （Au NCs） in a choline chloride-urea （ChCl-urea） based deep eutectic solvent （DES）. It was found that the growth overpotentials play a key role in tuning the shape of Au NCs. The shape evolution of Au NCs successively from concave rhombic dodecahedra （RD） to concave cubes, octopods, cuboctahedral boxes, and finally, to hollow octahedra （OH） was achieved by carefully controlling the growth overpotentials in the range from -0.50 to -0.95 V （vs. Pt quasi-reference electrode）. In addition, the presence of urea was important in the shape evolution of Au NCs. The surface structure of the as-prepared Au NCs was comprehensively characterized by scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and electrochemical studies. It was demonstrated that the electrocatalytic activity of the as-prepared Au NCs for D-glucose electrooxidation was sensitively dependent on their morphologies. The results illustrated that the dehydrogenated glucose adsorbed on concave RD and concave cubic Au NCs was preferentially transformed to gluconolactone at low electrode potentials. Subsequent gluconolactone oxidation occurred favorably on octopods with {111}-truncated arms and hollow OH at high electrode potential. This study opens up a new approach to develop the surface-structure-controlled growth of Au NCs by combining DES with electrochemical techniques. In addition, it is significant for the tuning of the electrocatalytic properties of NCs.

关键词： gold nanocrystals,shape evolution,electrochemical synthesis,deep eutectic solvent,glucose electrooxidation

Response of reed community to the environment gradientwater depth in the Yellow River Delta, China

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生物学前沿:英文版 2008年第2期3卷 194-202页

作者： Baoshan CUI xinsheng zhao Zhifeng YANG Bin CHEN Na TANG Xuejie TAN State Key Joint Laboratory of Environmental Simulation and Pollution Control School of EnvironmentBeijing Normal UniversityBeijing 100875China

We investigated and monitored a reed community in the fields.Data on the bio-ecological characteristics and β-diversity of reed communities in different environmental gradients(mainly based on water depth)of the Yellow River Delta were collected through multianalysis,extremum analysis and β-diversity index analysis.In accordance with the square sum of deviations(Ward)cluster analysis,10 sampling plots were divided into six types with the dominant plants in different plots varying according to the change in environmental gradients.The dominant plants in these plots varied from aquatic plants to xerophytes and salt tolerant plants as water depth decreased.The average height and diameter of the reeds at breast level were significantly correlated with the average water depth.The fitness curves of average density and coverage with average water depth were nonlinear.When the average water depth was 0.3 m,the average density and coverage of reeds reached the apex value,while the height and diameter of the reeds at breast level increased with the water depth.There were obvious changes to the environmental gradient in the Yellow River Delta.The transitional communities were also found to exist in the Yellow River Delta by β-diversity analysis.Vicarious species appeared with the change in water depth.The occurrence of substitute species is determined by the function of common species between adjacent belts.The different functions of common species led to differences in community structure and function and differences in dominant plants.The result reflects the variations of species present in different habitats and directly reflects environmental heterogeneity.The values of β-diversity indices of adjacent plots were higher than those of nonadjacent plots.There are transition zones between the xerophytes and aquatic plants in the Yellow River Delta.In an aquatic environment,the similarity of reed community is higher than that of xeromorphic plants.The β-diversity index can reflect plant succession trends caused by the change

关键词： reed β-diversity environmental gradient wetland the Yellow River Delta

2~5μm全固态中红外高功率光纤激光源研究进展(特邀)

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中国激光 2024年第1期51卷 97-123页

作者：李剑峰雷浩王森宇王壮钟文博谢昆林赵鑫生罗鸿禹电子科技大学光电科学与工程学院四川成都610097

2~5μm中红外波段激光在科学研究、生物医疗、通信等众多领域中都有重要的应用价值,一直以来都是激光领域的研究热点。主要对目前国内外高功率2~5μm全固态中红外光纤激光源的发展现状进行了梳理,包括稀土离子掺杂的中红外光纤激光器、... 详细信息

2~5μm中红外波段激光在科学研究、生物医疗、通信等众多领域中都有重要的应用价值,一直以来都是激光领域的研究热点。主要对目前国内外高功率2~5μm全固态中红外光纤激光源的发展现状进行了梳理,包括稀土离子掺杂的中红外光纤激光器、波长灵活可设计的拉曼光纤激光器和宽带超连续谱激光器,并对2~5μm全固态中红外光纤激光源的发展进行了展望。

关键词：激光器中红外激光稀土离子拉曼激光器超连续谱氟化物光纤

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西藏原始墨脱冷杉林微气候特征

高原科学研究 2024年第1期8卷 18-28页

作者：景梦洁赵旺林刘新圣张林安徽师范大学地理与旅游学院安徽芜湖241002 中国科学院青藏高原研究所北京100101 西藏自治区高原生物研究所生物资源与生物安全重点实验室西藏拉萨850000

受印度洋暖湿气流的影响,墨脱高海拔地带分布了大量的以墨脱冷杉(Abies delavayi var.motuoensis)为主的原始湿润森林,开展森林微气候研究能够为高寒生态脆弱区的植被保护和生态建设提供理论依据。文章基于2020年墨脱喜荣沟(海拔2700 m... 详细信息

受印度洋暖湿气流的影响,墨脱高海拔地带分布了大量的以墨脱冷杉(Abies delavayi var.motuoensis)为主的原始湿润森林,开展森林微气候研究能够为高寒生态脆弱区的植被保护和生态建设提供理论依据。文章基于2020年墨脱喜荣沟(海拔2700 m)原始冷杉林林内外的微气候监测数据,对比分析了林内与林外温度、湿度及不同深度土壤温度的季节变化特征,探讨了植物的生长季长度及生长季期间的低温事件发生情况。结果表明:(1)气温日变化特征显示,林内日间气温比林外低0.2∼2.7℃,森林表现出降温作用;除夏季外,其他季节林内夜间气温比林外均高0.2∼1.2℃,森林表现出保温作用;从季节变化看,林内外气温最高值出现在8月,最低值在1月,但林内气温较林外更加稳定;(2)该区域相对湿度较高(>80%),且在不同季节均表现为林内>林外;(3)除冬季外,土壤温度日变化总体呈现与气温类似的日动态,但土壤温度明显滞后约2∼3 h,林内土壤温度总体低于林外;春夏两季不同深度的土壤温度表现为5cm>10cm>20cm,而秋冬两季越靠近地表土壤温度则越低;(4)基于气温定义的生长季长度为208天,明显低于基于土壤温度定义的生长季长度(256∼268天);(5)2020年,冷杉林内低温事件发生的频率、强度及持续时间分别为1 d、-0.03℃和1 h,分别比林外少(低)了6 d、0.86℃和7 h。上述研究表明,原始墨脱冷杉林具有明显的保温和缓冲低温事件影响的作用,因此在未来亚高山天然林的保护和管理中应加强对森林微气候的观测和研究,不断提升天然林对气候变化的潜在应对能力。

关键词：低温事件气温土壤温度墨脱冷杉林生长季长度

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采棉机机架模态分析与优化

中国农机化学报 2024年第6期45卷 63-71页

作者：王光恒林慧王玉刚毕新胜裴婷稳赵鹏达石河子大学机械电气学院新疆石河子832000 农业农村部西北农业装备重点实验室新疆石河子832003 新疆生产建设兵团第八师农牧业机械化技术培训站石河子832000 山东天鹅棉业机械股份有限公司济南市250032

采棉机在工作时,会因载荷激励而导致机架振动,当激励频率在机架固有频率范围内,会产生共振现象,对采棉机产生影响。为提高采棉机工作性能,对采棉机机架进行模态分析,得到机架前6阶模态参数,通过分析振源激励特性,发现机架一阶和四阶模... 详细信息

采棉机在工作时,会因载荷激励而导致机架振动,当激励频率在机架固有频率范围内,会产生共振现象,对采棉机产生影响。为提高采棉机工作性能,对采棉机机架进行模态分析,得到机架前6阶模态参数,通过分析振源激励特性,发现机架一阶和四阶模态频率处在振源激励区间,将其与机架质量设为优化目标,机架各尺寸设定为设计变量;对机架进行灵敏度分析,基于CCD抽样设计并运用Kriging方法拟合响应面,运用多目标遗传算法得到5个优化方案,结合熵权法与线性加权法,其中方案1综合得分最高是最佳设计方案。优化后机架一阶模态频率97 Hz降低到91 Hz,四阶模态频率225 Hz增加到230 Hz,远离发动机激振频率100 Hz和220 Hz;质量为688.8 kg降低1.5%。经静力学与谐响应分析验证,优化后的机架满足工作要求。

关键词：采棉机模态分析振源激励灵敏度熵权法