检索结果-南通市图书馆

Pressure-induced color change arising from transformation between intra-and inter-band transitions in LuH_(2±x)N_(y)

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 161-166页

作者： Zhe Liu yingjie Zhang Shenyang Huang Xue Ming Qing Li Chenghao pan Yaomin Dai Xiaoxiang Zhou Xiyu Zhu Hugen Yan Hai-Hu Wen Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNational Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China State Key Laboratory of Surface Physics Key Laboratory of Micro and Nano-Photonic Structures of the Ministry of EducationDepartment of PhysicsFudan UniversityShanghai 200433China

The pressure-induced color change in the nitrogen-doped lutetium hydride has triggered extensive discussions about the underlying physics and potential applications.Here,we study the optical response of LuH_(2±x)N_(y)in a broad frequency range at ambient pressure and its evolution with pressure in the visible spectral range.The broad-band optical spectra at ambient pressure reveal a Drude component associated with intra-band electronic transitions and two Lorentz components(L1 and L2)arising from inter-band electronic transitions.The application of pressure causes a spectral weight transfer from L1 to the Drude component,leading to a blue shift of the plasma edge in the reflectivity spectrum alongside a reduction of the high-frequency reflectivity.Our results suggest that the pressure-induced color change in LuH_(2±x)N_(y)is closely related to the transformation between intra-and inter-band electronic transitions,providing new insights into the mechanism of the pressure-induced color change in LuH_(2±x)N_(y).

关键词： nitrogen-doped lutetium hydride optical spectroscopy high-pressure technique color change

A review of solid-state lithium metal batteries through in-situ solidification

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第1期67卷 67-86页

作者： pan Xu Zong-Yao Shuang Chen-Zi Zhao Xue Li Li-Zhen Fan Aibing Chen Haoting Chen Elena Kuzmina Elena Karaseva Vladimir Kolosnitsyn Xiaoyuan Zeng Peng Dong yingjie Zhang Mingpei Wang Qiang Zhang Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China National and Local Joint Engineering Laboratory for Lithium-ion Batteries and Materials Preparation Technology Key Laboratory of Advanced Battery Materials of Yunnan ProvinceFaculty of Metallurgical and Energy EngineeringKunming University of Science and TechnologyKunming 650093China Institute of Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China College of Chemical and Pharmaceutical Engineering Hebei University of Science and TechnologyShijiazhuang 050018China Ordos Carbon Neutral Research and Application Co. Ltd.Ordos City 017010China Ufa Institute of Chemistry UFRC RAS Ufa 450054Russia Institute for Carbon Neutrality Tsinghua UniversityBeijing 100084China Shanxi Research Institute for Clean Energy Tsinghua UniversityTaiyuan 030032China

High-energy-density lithium metal batteries are the next-generation battery systems of choice,and replacing the flammable liquid electrolyte with a polymer solid-state electrolyte is a prominent conduct towards realizing the goal of high-safety and high-specific-energy devices.Unfortunately,the inherent intractable problems of poor solid-solid contacts between the electrode/electrolyte and the growth of Li dendrites hinder their practical applications.The in-situ solidification has demonstrated a variety of advantages in the application of polymer electrolytes and artificial interphase,including the design of integrated polymer electrolytes and asymmetric polymer electrolytes to enhance the compatibility of solid–solid contact and compatibility between various electrolytes,and the construction of artificial interphase between the Li anode and cathode to suppress the formation of Li dendrites and to enhance the high-voltage stability of polymer electrolytes.This review firstly elaborates the history of in-situ solidification for solid-state batteries,and then focuses on the synthetic methods of solidified electrolytes.Furthermore,the recent progress of in-situ solidification technology from both the design of polymer electrolytes and the construction of artificial interphase is summarized,and the importance of in-situ solidification technology in enhancing safety is emphasized.Finally,prospects,emerging challenges,and practical applications of in-situ solidification are envisioned.

关键词： in-situ solidification polymer electrolyte artificial solid electrolyte interphase rechargeable lithium metal batteries dendrite-free lithium metal anode

Carbon inputs regulate the temperature sensitivity of soil respiration in temperate forests

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2022年第9期14卷 1055-1068页

作者： LIU Yulin LI Jiwei HAI Xuying WU Jianzhao DONG Lingbo pan yingjie SHANGGUAN Zhouping WANG Kaibo DENG Lei State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China University of Chinese Academy of Sciences Beijing 100049China Institute of Soil and Water Conservation Northwest Agriculture and Forestry UniversityYangling 712100China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710075China

Litter and root activities may alter the temperature sensitivity(Q_(10))of soil respiration.However,existing studies have not provided a comprehensive understanding of the effects of litter and root carbon inputs on the Q_(10)of soil respiration in different seasons.In this study,we used the trench method under in situ conditions to measure the total soil respiration(R_(total)),litter-removed soil respiration(R_(no-litter)),root-removed soil respiration(R_(no-root)),and the decomposition of soil organic matter(i.e.,both litter and root removal;R_(SOM))in different seasons of pioneer(Populus davidiana Dode)and climax(Quercus liaotungensis Mary)forests on the Loess Plateau,China.Soil temperature,soil moisture,litter biomass,fine root biomass,litter carbon,and root carbon were analyzed to obtain the drive mechanism of the Q_(10)of soil respiration in the two forests.The results showed that the Q_(10)of soil respiration exhibited seasonality,and the Q_(10)of soil respiration was higher in summer.The litter enhanced the Q_(10)of soil respiration considerably more than the root did.Soil temperature,soil moisture,fine root biomass,and litter carbon were the main factors used to predict the Q_(10)of different soil respiration components.These findings indicated that factors affecting the Q_(10)of soil respiration highly depended on soil temperature and soil moisture as well as related litter and root traits in the two forests,which can improve our understanding of soil carbon–climate feedback in global warming.The results of this study can provide reference for exploring soil respiration under temperate forest restoration.

关键词： litter biomass root carbon soil respiration temperate forests Loess Plateau

在线全文

学校读者我要写书评

暂无评论

ECC全包裹普通混凝土复合试件的力学性能

材料导报 2024年第3期38卷 108-113页

作者：康迎杰郭自利叶斌斌潘鹏石家庄铁道大学省部共建交通工程结构力学行为与系统安全国家重点实验室河北省风工程和风能利用工程技术创新中心石家庄铁道大学土木工程学院清华大学土木工程系清华大学土木工程安全与耐久教育部重点实验室

为综合利用工程用水泥基复合材料(ECC)在力学性能上和普通混凝土在成本上的优势，本工作提出了一种制备ECC全包裹普通混凝土复合试件的方法，通过进行抗压、抗拉及抗弯等试验系统研究了其基本力学性能，并采用数值分析方法对配筋复合梁... 详细信息

为综合利用工程用水泥基复合材料(ECC)在力学性能上和普通混凝土在成本上的优势，本工作提出了一种制备ECC全包裹普通混凝土复合试件的方法，通过进行抗压、抗拉及抗弯等试验系统研究了其基本力学性能，并采用数值分析方法对配筋复合梁进行了正截面受弯性能研究。结果表明：在复合试件受力破坏时，ECC和混凝土界面未出现滑移，两种材料黏结可靠实现了协同受力；相对普通混凝土试件而言，复合试件的抗压强度、抗拉强度及抗弯强度均有所提升，尤其是抗弯强度的提升最为显著，对于截面尺寸为100 mm×100 mm的梁，当ECC厚度分别为10 mm和15 mm时，抗弯强度可提高27.4%和57.1%;复合试件具有良好的延性变形能力，破坏后可保持一定的完整性，整体具备高韧性特征；与普通钢筋混凝土梁相比，配筋复合梁有效利用了ECC材料的性能优势，显著提升了配筋梁的承载和变形能力。

关键词：工程用水泥基复合材料复合试件力学性能延性破坏高韧性

HiFAST:An HIdata calibration and imaging pipeline for FAST

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 182-199页

作者： yingjie Jing Jie Wang Chen Xu Ziming Liu Qingze Chen Tiantian Liang Jinlong Xu Yixian Cao Jing Wang Huijie Hu Chuan-Peng Zhang Qi Guo Liang Gao Mei Ai Hengqian Gan Xuyang Gao Jinlin Han Ligang Hou Zhipeng Hou Peng Jiang Xu Kong Fujia Li Zerui Liu Li Shao Hengxing pan Jun pan Lei Qian Jinghai Sun Ningyu Tang Qingliang Yang Bo Zhang Zhiyu Zhang Ming Zhu National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 02206China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Guizhou Radio Astronomical Observatory Guizhou UniversityGuiyang 55000China Max Planck Institute for Extraterrestrial Physics Garching 85748Germany Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Institute of Computational Cosmology Department of PhysicsUniversity of DurhamDurham DHI 3LEUK CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Deep Space Exploration Laboratory/Department of Astronomy University of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Astrophysics Department of PhysicsUniversity of OxfordOxford OX/3RHUK College of Earth Sciences Guilin University of TechnologyGuilin 541004China Department of Physics Anhui Normal UniversityWuhu 241002China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics Nanjing UniversityNanjing 20023China

The Five-hundred-meter Aperture Spherical radio Telescope(FAST)has the largest aperture and a 19-beam L-band receiver,making it powerful for investigating the neutral hydrogen atomic gas(HI)in the universe.We present HiFAST(https://hifast.***.io),a dedicated,modular,and self-contained calibration and imaging pipeline for processing the H?data of FAST.The pipeline consists of frequency-dependent noise diode calibration,baseline fitting,standing wave removal using an FFT-based method,flux density calibration,stray radiation correction,and gridding to produce data cubes.These modules can be combined as needed to process the data from most FAST observation modes:tracking,drift scanning,On-The-Fly mapping,and most of their variants.With HiFAST,the root-mean-square(RMS)noises of the calibrated spectra from all 19 beams were only slightly(~5%)higher than the theoretical expectation.The results for the extended source M33 and the point sources are consistent with the results from Arecibo.The moment maps(0,1 and 2)of M33 agree well with the results from the Arecibo Galaxy Environment Survey(AGES)with a fractional difference of less than 10%.For a common sample of 221 sources with signal-to-noise ratio S/N>10 from the Arecibo Legacy Fast ALFA(ALFALFA)survey,the mean value of fractional difference in the integrated flux density,Sint,between the two datasets is approximately 0.005%,with a dispersion of 15.4%.Further checks on the integrated flux density of 23 sources with seven observations indicate that the variance in the flux density of the source with luminous objects(Sint>2.5 Jy km s-1)is less than 5%.Our tests suggest that the FAST telescope,with the efficient,precise,and user-friendly pipeline HiFAST,will yield numerous significant scientific findings in the investigation of the H?in the universe.

关键词： fractional luminous correction

基于光学与雷达遥感影像协作的多云雾区域农作物信息提取研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

遥感技术与应用 2024年第2期39卷 362-372页

作者：周兴霞王颖洁杨攀自然资源部第三航测遥感院四川成都610100

及时掌握农作物分布信息,对农业结构调整和国家粮食安全保障具有重要的战略意义。然而,多云雾区域受气候条件制约,难以获取全时序的光学影像,无法构建涵盖农作物完整生长季的物候特征数据集,农作物信息提取受到限制。因此,本研究以西南... 详细信息

及时掌握农作物分布信息,对农业结构调整和国家粮食安全保障具有重要的战略意义。然而,多云雾区域受气候条件制约,难以获取全时序的光学影像,无法构建涵盖农作物完整生长季的物候特征数据集,农作物信息提取受到限制。因此,本研究以西南多云雾区域重要的产粮地之一——四川省广汉市为例,基于SAR影像(Sentinel-1)和光学影像(Sentinel-2)数据协作,构建了研究区冬季农作物典型时相光谱特征和夏季农作物SAR时序特征,采用面向对象决策树分类方法,提取了研究区农作物时空分布信息并进行精度分析。结果表明:①广汉市农作物以粮油作物为主,主要包括小麦-水稻、油菜-水稻、土豆-大豆、土豆-玉米4种一年两熟的轮作种植模式。②水稻、大豆、玉米3种夏季农作物SAR时序特征差异明显,光学-雷达遥感数据协作提取冬季-夏季农作物类型及空间分布为多云雾区域农作物信息提取提供了新的思路。③面向对象的决策树分类方法分类总体精度和Kappa系数分别为85.49%和0.81,分类结果保持了大面积作物的完整性,避免了分类结果的“椒盐现象”。

关键词：光学遥感雷达遥感多云雾区域面向对象农作物信息

HiFAST:An H?data calibration and imaging pipeline for FAST

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第5期Mechanics & Astronomy) .卷 186-203页

作者： yingjie Jing Jie Wang Chen Xu Ziming Liu Qingze Chen Tiantian Liang Jinlong Xu Yixian Cao Jing Wang Huijie Hu Chuan-Peng Zhang Qi Guo Liang Gao Mei Ai Hengqian Gan Xuyang Gao Jinlin Han Ligang Hou Zhipeng Hou Peng Jiang Xu Kong Fujia Li Zerui Liu Li Shao Hengxing pan Jun pan Lei Qian Jinghai Sun Ningyu Tang Qingliang Yang Bo Zhang Zhiyu Zhang Ming Zhu School of Astronomy and Space Science University of Science and Technology of China Astrophysics Department of PhysicsUniversity of Oxford College of Earth Sciences Guilin University of Technology Department of Physics Anhui Normal University School of Astronomy and Space Science Nanjing University Key Laboratory of Modern Astronomy and Astrophysics Nanjing University National Astronomical Observatories Chinese Academy of Sciences Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University School of Astronomy and Space Science University of Chinese Academy of Sciences Guizhou Radio Astronomical Observatory Guizhou University Max Planck Institute for Extraterrestrial Physics Kavli Institute for Astronomy and Astrophysics Peking University Institute of Computational Cosmology Department of PhysicsUniversity of Durham CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of Sciences Deep Space Exploration Laboratory/Department of Astronomy University of Science and Technology of China

The Five-hundred-meter Aperture Spherical radio Telescope（FAST） has the largest aperture and a 19-beam L-band receiver,making it powerful for investigating the neutral hydrogen atomic gas（H?） in the universe.We present HiFAST（https://hifast.***.io）,a dedicated,modular,and self-contained calibration and imaging pipeline for processing the H?data of FAST.The pipeline consists of frequency-dependent noise diode calibration,baseline fitting,standing wave removal using an FFT-based method,flux density calibration,stray radiation correction,and gridding to produce data cubes.These modules can be combined as needed to process the data from most FAST observation modes:tracking,drift scanning,On-The-Fly mapping,and most of their variants.With HiFAST,the root-mean-square（RMS） noises of the calibrated spectra from all 19 beams were only slightly（～5%） higher than the theoretical expectation.The results for the extended source M33 and the point sources are consistent with the results from Arecibo.The moment maps（0,1 and 2） of M33 agree well with the results from the Arecibo Galaxy Environment Survey（AGES） with a fractional difference of less than 10%.For a common sample of 221 sources with signal-to-noise ratio S/N>10 from the Arecibo Legacy Fast ALFA（ALFALFA） survey,the mean value of fractional difference in the integrated flux density,Sint,between the two datasets is approximately 0.005%,with a dispersion of 15.4%.Further checks on the integrated flux density of 23 sources with seven observations indicate that the variance in the flux density of the source with luminous objects(Sint>2.5 Jy km s-1) is less than 5%.Our tests suggest that the FAST telescope,with the efficient,precise,and user-friendly pipeline HiFAST,will yield numerous significant scientific findings in the investigation of the H? in the universe.

关键词：

截屏社交的“刺猬困境”——聊天记录再传播中隐私边界的游移与重塑

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

台州学院学报 2024年第1期46卷 86-92页

作者：戴颖洁潘茹雪浙江传媒学院新闻与传播学院浙江杭州310018

截屏社交指个体将聊天内容截屏并转发给他人,以期拉近社交距离的行为。截屏社交会打破聊天双方的隐私平衡,使原本私密的聊天记录面临隐私风险。对此,个体需保持边界敏感、重塑边界契约;平台需提供技术支持,加强用户信息自决权、强化审... 详细信息

截屏社交指个体将聊天内容截屏并转发给他人,以期拉近社交距离的行为。截屏社交会打破聊天双方的隐私平衡,使原本私密的聊天记录面临隐私风险。对此,个体需保持边界敏感、重塑边界契约;平台需提供技术支持,加强用户信息自决权、强化审核把关、简化维权通道;法律应破除适用障碍,从法理层面与实践层面共同着手,保障截屏社交中的信息安全。

关键词：传播隐私管理理论截屏社交隐私边界隐私权

在线全文

学校读者我要写书评

暂无评论

大豆皂苷结构及生理活性研究进展

食品科学技术学报 2024年第1期42卷 69-82页

作者：朱力杰潘月影李英燕周英杰白昕雯刘秀英刘贺渤海大学食品科学与工程学院/生鲜农产品贮藏加工及安全控制技术国家地方联合工程研究中心辽宁锦州121013 武汉轻工大学食品科学与工程学院湖北武汉430023

大豆皂苷大量存在于大豆的胚芽、胚轴等部分,尤其是在脱脂豆粕中含量丰富,可以作为一类高附加值的产品进行生产,提高大豆油加工副产物的利用率。大豆皂苷属于五环三萜类化合物,是一种齐墩果烷型皂苷,由疏水性苷元和亲水性糖基组成,具有... 详细信息

大豆皂苷大量存在于大豆的胚芽、胚轴等部分,尤其是在脱脂豆粕中含量丰富,可以作为一类高附加值的产品进行生产,提高大豆油加工副产物的利用率。大豆皂苷属于五环三萜类化合物,是一种齐墩果烷型皂苷,由疏水性苷元和亲水性糖基组成,具有一定的两亲性,并具有抗肿瘤、抗炎、抗氧化、调节免疫力、保护肝脏等多种生理活性。近年来,大豆皂苷的研究领域从活性验证到分子机制不断拓展,产出了一批具有前瞻性的研究成果。不同结构与类型的大豆皂苷表现出的生理活性及作用机制不同,相关研究为大豆皂苷在食品和医药等领域的应用提供了理论基础。重点阐述了大豆皂苷的结构与分类、生理活性及构效关系的最新研究进展,分析了加工方式对大豆皂苷结构的影响,总结了大豆皂苷发挥生理活性的机制及其基于生理活性的应用,剖析了大豆皂苷在未来应用中亟待解决的问题,以期为大豆皂苷进一步研究和开发利用提供理论依据。

关键词：大豆皂苷化学结构生物合成生理活性构效关系