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Revealing the role of calcium ion intercalation of hydrated vanadium oxides for aqueous zinc-ion batteries

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Journal of Energy Chemistry 2024年第8期95卷 9-19,I0001页

作者： Tao Zhou xuan du Guo Gao Key Laboratory for Thin Film and Micro Fabrication of the Ministry of Education School of Sensing Science and EngineeringSchool of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Exploring suitable high-capacity V_(2)O_(5)-based cathode materials is essential for the rapid advancement of aqueous zinc ion batteries(ZIBs).However,the typical problem of slow Zn^(2+)diffusion kinetics has severely limited the feasibility of such *** this work,unique hydrated vanadates(CaVO,BaVO)were obtained by intercalation of Ca^(2+)or Ba^(2+)into hydrated vanadium *** the CaVO//Zn and BaVO//Zn batteries systems,the former delivered up to a 489.8 mAh g^(-1)discharge specific capacity at 0.1 A g^(-1).Moreover,the remarkable energy density of 370.07 Wh kg^(-1)and favorable cycling stability yard outperform BaVO,pure V_(2)O_(5),and many reported cathodes of similar ionic intercalation *** addition,pseudocapacitance analysis,galvanostatic intermittent titration(GITT)tests,and Trasatti analysis revealed the high capacitance contribution and Zn^(2+)diffusion coefficient of CaVO,while an in-depth investigation based on EIS elucidated the reasons for the better electrochemical performance of ***,ex-situ XRD,XPS,and TEM tests further demonstrated the Zn^(2+)insertion/extraction and Zn-storage mechanism that occurred during the cycle in the CaVO//Zn battery *** work provides new insights into the intercalation of similar divalent cations in vanadium oxides and offers new solutions for designing cathodes for high-capacity aqueous ZIBs.

关键词： Aqueous zinc ion batteries Cathode materials Ion pre-intercalation Vanadium oxides Energy storage mechanism

Interactions of Lump and Solitons to Generalized(2 + 1)-Dimensional Ito Systems

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Communications in Theoretical Physics 2019年第6期71卷 633-639页

作者： xuan du Sen-Yue Lou Department of Mathematics Ningbo UniversityNingbo315211China School of Physical Science and Technology Ningbo UniversityNingbo315211China Shanghai Key Laboratory of Trustworthy Computing East China Normal UniversityShanghai200062China

The(2 + 1)-dimensional Ito equation is extended to a general form including some nonintegrable effects via introducing generalized bilinear operators. It is pointed out that the nonintegrable(2 + 1)-dimensional Ito equation contains lump solutions and interaction solutions between lump and stripe solitons. The result shows that the lump soliton will be swallowed or arisen by a stripe soliton in a fixed time. Furthermore, by the interaction between a lump and a paired resonant stripe soliton, the lump will be transformed to an instanton or a rogue wave.

关键词： generalized bilinear operators (2 + 1)-dimensional Ito systems lump-soliton interactions instanton and rogue waves

Conservation management decreases surface runoff and soil erosion

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International Soil and Water Conservation Research 2022年第2期10卷 188-196页

作者： xuan du Jinshi Jian Can du Ryan D.Stewart Department of Hydraulic Engineering Yangling Vocational&Technical CollegeYang LingShaanxiChina State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F UniversityYangling712100China Pacific Northwest National Laboratory-University of Maryland Joint Global Change Research Institute 5825 University Research CourtSuite3500College ParkMDUSA Department of Bioengineering Yangling Vocational&Technical CollegeYang LingShaanxiChina School of Plant and Environmental Sciences Virginia

Conservation management practices e including agroforestry,cover cropping,no-till,reduced tillage,and residue return e have been applied for decades to control surface runoff and soil erosion,yet results have not been integrated and evaluated across cropping *** this study we collected data comparing agricultural production with and without conservation management *** used a bootstrap resampling analysis to explore interactions between practice type,soil texture,surface runoff,and soil *** then used a correlation analysis to relate changes in surface runoff and soil erosion to 13 other soil health and agronomic indicators,including soil organic carbon,soil aggregation,infil-tration,porosity,subsurface leaching,and cash crop *** all conservation management practices,surface runoff and erosion had respective mean decreases of 67%and 80%compared with *** of cover cropping provided the largest decreases in erosion and surface runoff,thus emphasizing the importance of maintaining continuous vegetative cover on ***-and medium-textured soils had greater decreases in both erosion and runoff than fine-textured *** in surface runoff and soil erosion under conservation management were highly correlated with soil organic carbon,aggregation,porosity,infiltration,leaching,and yield,showing that conservation practices help drive important in-teractions between these different facets of soil *** study offers the first large-scale comparison of how different conservation agriculture practices reduce surface runoff and soil erosion,and at the same time provides new insight into how these interactions influence the improvement or loss of soil health。

关键词： Conservation management Soil erosion Runoff Meta-analysis Soil he

Characterization of personal exposure concentration of fine particles for adults and children exposed to high ambient concentrations in Beijing, China

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Journal of Environmental Sciences 2010年第11期22卷 1757-1764页

作者： xuan du Qian Kong Weihua Ge Shaojun Zhang Lixin Fu Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China Xi' an Municipal Engineering Design and Research Institute Co. Ltd. Xi'an 710068 China

In China, the health risk from overexposure to particles is becoming an important public health concern. To investigate daily exposure characteristics to PM 2.5 with high ambient concentration in urban area, a personal exposure study was conducted for school children, and office workers in Beijing, China. For all participants （N = 114）, the mean personal 24-hr exposure concentration was 102.5, 14.7, 0.093, 0.528, 0.934, 0.174 and 0.703 μg/m 3 for PM 2.5 , black carbon, Mn, Al, Ca, Pb, and Fe. Children’s exposure concentrations of PM 2.5 were 4–5 times higher than those in related studies. The ambient concentration of PM 2.5 （128.5 μg/m 3 ） was significantly higher than the personal exposure concentration （P 0.05）, and exceed the reference concentration （25 μg/m 3 ） of WHO air quality guideline. Good correlation relationships and significant differences were identified between ambient concentration and personal exposure concentration. The relationships indicate that the ambient concentration is the main factor influencing personal exposure concentration, but is not a good indicator of personal exposure concentration. Outdoor activities （commute mode, exposure to heating, workday or weekend travel） influenced personal exposure concentrations significantly, but the magnitude of the influence from indoor activities （exposure to cooking） was masked by the high ambient concentrations.

关键词： personal exposure PM 2.5 high ambient concentration

Prediction of structured void-containing 1T-PtTe2 monolayer with potential catalytic activity for hydrogen evolution reaction

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Chinese Physics B 2020年第5期29卷 530-533页

作者： Bao Lei Yu-Yang Zhang Shi-xuan du Institute of Physics and University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100190China CAS Center for Excellence in Topological Quantum Computation Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

Two-dimensional(2D)transition metal dichalcogenides(TMDs)have attracted considerable attention because of their unique properties and great potential in nano-technology *** efforts have been devoted to fabrication of novel structured TMD monolayers by modifying their pristine structures at the atomic *** we propose an intriguing structured 1T-PtTe2 monolayer as hydrogen evolution reaction(HER)catalyst,namely,Pt4Te7,using first-principles *** is found that Pt4Te7 is a stable monolayer material verified by the calculation of formation energy,phonon dispersion,and ab initio molecular dynamics ***,the novel structured void-containing monolayer exhibits superior catalytic activity toward HER compared with the pristine one,with a Gibbs free energy very close to zero(less than 0.07 eV).These features indicate that Pt4Te7 monolayer is a high-performance HER catalyst with a high platinum *** findings open new perspectives for the functionalization of 2D TMD materials at an atomic level and its application in HER catalysis.

关键词： first-principles calculations structured PtTe2 monolayer void-containing materials HER catalyst

Band engineering of B_2H_2 nanoribbons

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Chinese Physics B 2019年第4期28卷 305-309页

作者： Bao Lei Yu-Yang Zhang Shi-xuan du Institute of Physics Chinese Academy of Sciences (CAS) University of Chinese Academy of Sciences CAS Center for Excellence in Topological Quantum Computation Chinese Academy of Sciences

Freestanding honeycomb borophene is unstable due to the electron-deficiency of boron atoms. B_2H_2 monolayer, a typical borophene hydride, has been predicted to be structurally stable and attracts great attention. Here, we investigate the electronic structures of B_2H_2 nanoribbons. Based on first-principles calculations, we have found that all narrow armchair nanoribbons with and without mirror symmetry(ANR-s and ANR-as, respectively) are semiconducting. The energy gap has a relation with the width of the ribbon. When the ribbon is getting wider, the gap disappears. The zigzag ribbons without mirror symmetry(ZNR-as) have the same trend. But the zigzag ribbons with mirror symmetry(ZNR-s) are always metallic. We have also found that the metallic ANR-as and ZNR-s can be switched to semiconducting by applying a tensile strain along the nanoribbon. A gap of 1.10 eV is opened under 16% strain for the 11.0-■ ANR-as. Structural stability under such a large strain has also been confirmed. The flexible band tunability of B_2H_2 nanoribbon increases its possibility of potential applications in nanodevices.

关键词： borophene hydride nanoribbons band engineering first-principles calculations strain

Thickness-dependent magnetic order and phase transition in V5S8

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Chinese Physics B 2020年第7期29卷 516-520页

作者： Rui-Zi Zhang Yu-Yang Zhang Shi-xuan du Institute of Physics&University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100190China CAS Centre for Excellence in Topological Quantum Computation Beijing 100190China

V5S8 is an ideal candidate to explore the magnetism at the two-dimensional(2D)limit.A recent experiment has shown that the V5S8 thin films exhibit an antiferromagnetic(AFM)to ferromagnetic(FM)phase transition with reducing ***,for the first time,using density functional theory calculations,we report the antiferromagnetic order of bulk V5S8,which is consistent with the previous *** specific antiferromagnetic order is reproduced when Ueff=2 eV is applied on the intercalated vanadium atoms within *** find that the origin of the magnetic ordering is from superexchange *** also investigate the thickness-dependent magnetic order in V5S8 thin *** is found that there is an antiferromagnetic to ferromagnetic phase transition when V5S8 is thinned down to 2.2 *** main magnetic moments of the antiferromagnetic and ferromagnetic states of the thin films are located on the interlayered vanadium atoms,which is the same as that in the ***,the strain in the thin films also influences the AFM-FM phase *** results not only reveal the magnetic order and origin in bulk V5S8 and thin films,but also provide a set of parameters which can be used in future calculations.

关键词： V5S8 superexchange interaction AFM-FM phase transition

Activation and Deactivation of Chain-transfer Agent in Controlled Radical Polymerization by Oxygen Initiation and Regulation

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Chinese Journal of Polymer Science 2020年第11期38卷 1178-1184,I0006页

作者： Chun-Na Lv Ning Li Yu-xuan du Jia-Hua Li Xiang-Cheng Pan State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai200438China

The activation and deactivation of the chain-transfer agent were achieved by oxygen initiation and regulation with triethylborane under ambient temperature and *** autoxidation of triethylborane overcame the oxygen inhilbition and produced initiating radicals that selectively activate the chain-transfer agent for the chain growth or deactivate the active chain-end of polymer in controlled radical *** activation and deactivation were highly efficient with broad scope for various polymers with different chain-transfer agents in both organic and aqueous *** molecule was particularly used as an external regulator to initiate and achieve the temporal control of both activation and deactivation by simply feeding the air.

关键词： RAFT Oxygen Borane

大熊猫国家公园生态敏感性时空演变特征分析——以九寨沟-黄龙-王朗片区为例

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绿色科技 2025年第02期27卷 82-88+96页

作者：杜璇钱丽源赵联军周斯翔西南交通大学建筑学院王朗国家级自然保护区

随着气候变化及人类活动干扰的不断增强，自然保护区内栖息地破碎化加剧，生物多样性正面临前所未有的挑战。以两处世界自然遗产在内的大熊猫国家公园九寨沟-黄龙-王朗片区为研究对象，对其人为干扰下的生态敏感性进行科学评价。采用201... 详细信息

随着气候变化及人类活动干扰的不断增强，自然保护区内栖息地破碎化加剧，生物多样性正面临前所未有的挑战。以两处世界自然遗产在内的大熊猫国家公园九寨沟-黄龙-王朗片区为研究对象，对其人为干扰下的生态敏感性进行科学评价。采用2013年和2022年的高程、植被覆盖度、土地利用等基础数据，通过层次分析法，选取6类指标因子，研究区域生态敏感性。结果表明：2013-2022年生态敏感性区域始终以高度敏感性区域为主，不敏感性区域与轻度敏感性区域占比增加，面积分别增加599.7、2256.46 hm2;中度敏感性区域与极度敏感性区域占比分别减少1.2%、0.8%,总体呈下降趋势。各级生态敏感性区域重心迁移整体表现离散程度较小，核密度分析发现极度敏感性区域分布破碎化程度明显升高。

关键词：生态敏感性国家公园时空演变层次分析法