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Boron nitride nanofibers enhanced composite PEO-based solid-state polymer electrolytes for lithium metal batteries

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Chinese Chemical Letters 2024年第6期35卷 216-221页

作者： Qianqian Song Yunting Zhang Jianli Liang si liu Jian Zhu Xingbin Yan School of Materials Science and Engineering Sun Yat-Sen UniversityGuangzhou 510275China College of Physics and Materials Science Tianjin Normal UniversityTianjin 300387China Department of Chemistry&Center of Super-Diamond and Advanced Films(COSDAF) City University of Hong KongHong Kong 999077China Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology School of Physics and Optoelectronic EngineeringFoshan UniversityFoshan 528225China

Polyethylene oxide(PEO)-based solid-state polymer electrolytes(SPEs)are limited by their poor cyclic stability and inferior ionic conductivity for applicating in high-safety,long-cycling and high-energy-density lithium metal batteries.Herein,porous boron nitride nanofibers(BNNFs)are filled into PEO-based SPE,which significantly suppresses Li dendrites growth and enhances the electrochemical performance of Li metal battery.BNNFs with high porosity have more active sites to connect with PEO,which can effectively reduce the crystallinity of the PEO matrix and enhance its ionic conductivity.Moreover,owing to the hardness and good stability of BNNFs,BNNFs/PEO/Li TFsi electrolyte exhibits a wider electrochemical window,better mechanical property and higher thermal stability compared with PEO/Li TFsi electrolyte.Consequently,the Li symmetric cell composed of 1%BNNFs/PEO/Li TFsi performs good cyclic stability(>1800 h),and the Li||1%BNNFs/PEO/Li TFsi||LFP full battery shows obviously improved performances in charge-discharge polarization voltage,discharge specific capacity,rate performance and cyclic stability than the Li||PEO/Li TFsi||LFP battery.

关键词： Solid-state polymer electrolyte Boron nitride nanofibers Lithium metal battery Ionic conductivity Li dendrite

Homochirality in Ferroelectrochemistry

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Chinese Journal of Chemistry 2024年第10期42卷 1133-1144页

作者： Hang Peng Jun-Chao Qi Yu-si liu Jia-Mei Zhang Wei-Qiang Liao Ren-Gen Xiong Ordered Matter Science Research Center Nanchang UniversityNanchangJiangxi 330031China

What is the most favorite and original chemistry developed in your research group?We originally proposed the design principle for molecular ferroelectrics:ferroelectrochemistry,including quasi-spherical theory,the introduction of homochirality,and H/F substitution.Ferroelectrochemistry changed the blind search for molecular ferroelectrics into targeted chemical design,which will develop into a new discipline.

关键词： Molecular ferroelectrics Homochirality Ferroelectricity Chemical design Point groups

A universal polymer-assisted route to fabricate Zr-doped TiO2 nanocomposite: boosting reactive desulfurization

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Tungsten 2024年第3期6卷 596-609页

作者： Yue Du Ping Li Zhi-Yi Zhong Wen-Xue Chen Yi-si liu Yun-Long Xie Li-Na Zhou Kai Wang Hubei Key Laboratory of Photoelectric Materials and Devices College of Material Science and Engineering Hubei Normal University National Laboratory of Solid State Microstructures Nanjing University College of Urban and Environmental Sciences Huangshi Key Laboratory of Prevention and Control of Soil Pollution Hubei Normal University School of Chemistry Chemical Engineering and Biotechnology Nanyang Technological University

A series of transition metal ion-doped TiO2composites were prepared by polyethyleneimine-assisted solvent-free selfassembly.Due to the similar electronegativity and ionic radius of Ti and Zr ions,the introduction of Zr element to TiO2can effectively improve its surface acidity and introduce more defect sites on the TiO2framework.As-fabricated Zr-doped TiO2nanocomposite exhibits the formation of Zr-Ti bond,strong surface acidity,connected mesoporous channels,and relatively high crystallinity.These remarkable properties contribute to its adsorption-oxidation-desulfurization capacity toward thiophene-type sulfides,which can remove 500 ×10-6dibenzothiophene from the model fuel within 100 min at low reaction temperatures.The polymer-induced self-assembly method can reduce organic solvent usage,pollutant emissions,and energy consumption,which provides an efficient and practical way to prepare porous metal oxide-based catalysts in future.

关键词： Oxidative desulfurization Transition metal ion-doped TiO 2 nanocomposite Dibenzothiophene Solvent-free self-assembly method

基于改进K均值聚类的光谱重建训练样本选择研究

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光谱学与光谱分析 2024年第1期44卷 29-35页

作者：刘振刘莉樊硕赵安然刘思鲁曲阜师范大学传媒学院山东日照276800 曲阜师范大学工学院山东日照276800

光谱反射率重建过程中,训练样本的选择方法及样本容量与重建精度密切相关,寻找一种高效的训练样本选择方法是光谱重建的目标之一。K均值聚类计算复杂度小,计算效率高,但因聚类初始值选择的随机性,以及离群点的影响致使聚类结果不稳定,... 详细信息

光谱反射率重建过程中,训练样本的选择方法及样本容量与重建精度密切相关,寻找一种高效的训练样本选择方法是光谱重建的目标之一。K均值聚类计算复杂度小,计算效率高,但因聚类初始值选择的随机性,以及离群点的影响致使聚类结果不稳定,进而影响光谱重建的精度。基于此,提出了一种改进K均值聚类的训练样本选择方法。首先,将训练样本集的几何中心作为聚类中心的初始值;其次,基于高斯函数构建样本空间分布概率密度函数,并以欧几里德(欧式)距离作为其他聚类中心的度量依据;最后,在训练样本集中,基于簇内平方差度量光谱反射率样本间的相似度,将每个聚类子集中与中心距离最近的样本作为训练样本。为验证该方法的有效性,通过主成分分析法进行光谱重建。实验结果表明,所提的方法相较于传统的方法,光谱重建精度有一定的提高,重建光谱的平均均方根误差小于4%, CIE DE2000色差小于3.756 7。提出的改进的K均值聚类的训练样本选择方法,能够一定程度上提高了光谱重建精度,基本满足复制再现图像的要求。

关键词：光谱重建训练样本聚类算法改进K均值聚类

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Science China(Technological Sciences) 2022年第1期65卷 131-138页

作者： YANG Chang WANG ZongQiang XIAO FuLiang HE ZhaoGuo XIE YanQiong ZHANG Sai HE YiHua liu si ZHOU QingHua School of Physics and Electronic Sciences Changsha University of Science and TechnologyChangsha 410114China Sate Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190China Planetary Environmental and Astrobiological Research Laboratory(PEARL) School of Atmospheric SciencesSun Yat-sen UniversityZhuhai 519082China College of Meteorology and Oceanography National University of Defense TechnologyNanjing 211101China

Electromagnetic ion cyclotron(EMIC)emission is an efficient mechanism for scattering loss of energetic protons.Here,we report an event that provides both in-situ observation of energetic proton differential fluxes in the inner magnetosphere and precipitation of protons at ionospheric altitudes.During the 7-8 September 2015 geomagnetic storm the Van Allen Probes observed strong EMIC waves around L=5 and a distinct decrement in fluxes of tens of keV protons around pitch angles 0°-45°.Meanwhile,precipitating protons at ionospheric altitudes were found to significantly enhanced(by several orders of magnitude),measured by NOAA 18 and 19 when they magnetically linked to the Van Allen Probe-A.By solving the Fokker-Planck diffusion equation,we show that EMIC waves can efficiently produce loss of energetic protons within about 2 h in the pitch angle range of~0°-45°,comparable to the satellite observations.

关键词： wave-particle interaction EMIC waves energetic proton scattering loss

Interaction and coordinated development between desertification control and social economy in Xizang,China

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Ecological Economy 2024年第2期20卷 160-177页

作者： ZHU Cai-xia ZHENG Yu-jie liu si-yu QIN Tao School of Economics and Management Beijing Forestry UniversityBeijing 100083CHINA

Based on the general requirements of the coordinated development of"ecological livable"and"affluent life"in the rural revitalization strategy,the evaluation index system of desertification control was constructed,the interaction between desertification control and regional social economy and the internal space-time coordination mechanism were explored,and the quality of desertification control and its coordination degree with regional economic development were quantitatively analyzed.The decoupling mechanism of desertification governance society economy system were analyzed,and the high level for the government to promote desertification governance,constructing ecological economy coordinated development pattern to provide decision basis to Xizang desertification governance-social economic system interaction and coupling coordination development as the research object,introducing the coupling decoupling model to measure the coupling coordination model and system coordination and decoupling decoupling.Desertification control in Xizang shows a trend of gradual improvement,but the overall level is still not high and there is a lot of room for optimization.The coupling coordination degree of desertification control-social and economic system is in a steady fluctuation trend,rising from D value less than 0.55 in 2004 to 0.87 in 2018,in a state of coordinated development(good),and grey prediction analysis shows that D value is in a continuous rise.The coupling coordination degree of the six prefecture-level cities in Xizang and Ngari region is different in time and space,but the overall development trend is coordinated.The development index of desertification control and the socio-economic development index show the interaction of strong decoupling,strong negative decoupling and weak decoupling,and there are interaction effects of desertification control,economic development and social development at different scales.

关键词： desertification control coupling coordination model decoupling model economic development

Observations and parametric study on the role of plasma density on extremely low-frequency chorus wave generation

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Science China(Technological Sciences) 2022年第11期65卷 2649-2657页

作者： HE Qian liu si XIAO FuLiang GAO ZhongLei LI Tong SHANG XiongJun ZHOU QingHua YANG Chang HE YiHua School of Physics and Electronic Sciences Changsha University of Science and TechnologyChangsha 410114China

Extremely low-frequency(ELF)chorus waves with frequencies below 0.1 fcecan cause the scattering losses of relativistic electrons.Previous studies have suggested that ELF chorus waves are excited by anisotropic electrons with energies up to a few hundred ke V.Here,we report an interesting event observed using the Van Allen Probes on November 1,2012,where distinct ELF chorus waves occurred exactly corresponding to the enhancement of the plasma density.Using the correlated data of particles and plasma environments,the continuous calculation of growth rates along the satellite trajectory was conducted.The linear analysis results display a similar pattern to the observation results.To further identify the impact of the plasma density on the frequency control of ELF chorus waves,the growth rates were then calculated by only changing the value of the plasma density.The calculation results show that the growth rates move to lower frequencies with plasma density enhancement during the event.These findings indicate that the increased plasma density has a considerable impact on the wave frequency.The current study can enrich our understanding of the possible role of plasma density on the generation of ELF chorus waves.

关键词： radiation belts plasma density extremely low-frequency chorus waves numerical simulation

习近平总书记关于推动长江经济带发展重要论述的内涵要义、内蕴方法及创新贡献

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改革 2024年第2期 1-14页

作者：刘嗣方重庆社会科学院

推动长江经济带发展是关系国家发展全局的重大战略,对推进强国建设、民族复兴具有重要意义。习近平总书记关于推动长江经济带发展重要论述是习近平新时代中国特色社会主义思想的重要组成部分。习近平总书记关于推动长江经济带发展重要... 详细信息

推动长江经济带发展是关系国家发展全局的重大战略,对推进强国建设、民族复兴具有重要意义。习近平总书记关于推动长江经济带发展重要论述是习近平新时代中国特色社会主义思想的重要组成部分。习近平总书记关于推动长江经济带发展重要论述的内涵要义体现在:生态优先、绿色发展是长江经济带发展的战略定位,促进区域协调发展是长江经济带发展的重要举措,创新引领发展是长江经济带发展的动力引擎,构建新发展格局是长江经济带发展的战略支撑,繁荣发展长江文化是长江经济带发展的内在要求,统筹发展和安全是长江经济带发展的坚实保障。坚持系统观念、坚持改革创新、坚持发展和保护相统一、坚持政府和市场相结合、坚持底线思维、坚持久久为功是习近平总书记关于推动长江经济带发展重要论述蕴含的科学方法。习近平总书记关于推动长江经济带发展重要论述的创新贡献体现在:展现以新发展理念为指引推进长江经济带科学保护、开发和治理,贡献了破解超大流域发展和治理难题的原创经验;展现实践中国式现代化国家治理理论,形塑了超大流域发展和治理的崭新格局;展现发挥黄金水道“黄金经济带”效应,打造了超大流域发展和治理的实践样本;展现构建新发展格局、统筹发展和安全,强化了超大流域发展和治理的支撑保障;展现探索中国特色自主知识体系,推动了超大流域发展和治理的学科体系、学术体系和话语体系建构;展现促进世界大江大河流域发展和治理全球文明交流互鉴,拓展了超大流域发展和治理的中华民族现代文明意蕴。

关键词：长江经济带发展生态优先绿色发展科学方法创新贡献

In-flight vector magnetometer calibration for FY-3E satellite

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Science China(Technological Sciences) 2023年第6期66卷 1867-1868页

作者： WANG YongFu YU XiangQian ZONG QiuGang XIAO ChiJie liu si CHEN HongFei ZOU Hong SHI WeiHong School of Earth and Space Sciences Peking UniversityBeijing 100871China School of Physics Peking UniversityBeijing 100871China School of Physics and Electronic Science Changsha University of Science&TechnologyChangsha 410114China

The FY-3E meteorological satellite was launched by China on July 5,2021.The orbit of the satellite is sun-synchronous with an orbit altitude 836 km and orbit period 102 min.The satellite is equipped with a triaxial anisotropic magnetore-sistance magnetometer to detect ultra-low frequency waves in the magnetosphere.The magnetometer sensor is situated on the satellite truss.It is approximately 1 m away from the satellite body to reduce the effect of spacecraft fields.

关键词： magnetometer satellite equipped