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Realizing high initial Coulombic efficiency in manganese-based layered oxide cathodes for sodium-ion batteries via P2/O'3 biphasic structure optimization

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Rare Metals 2024年第5期43卷 2093-2102页

作者： Bo Peng Zi-Hao Zhou Ping Xuan Jie Xu Lian-Bo Ma School of Materials Science and Engineering Anhui University of Technology Anhui Product Quality supervision&Inspection Research Institute

Abstract Mn-based layered oxides are among the most promising cathode materials for sodium-ion batteries owing to the advantages of abundance,environmenta friendliness,low cost and high specific capacity.P2 and O'3 are two representative structures of Mn-based layered oxides.However,the P2 structure containing insufficien Na generally exhibits low initial charge capacity,while O'3structure with sufficient Na delivers high initial charge capacity but poor cycle stability.This study prepared a multitude of NaxMnO2（x=0.7,0.8,0.9） cathode materials with varying P2/O'3 ratios and further investigated their electrochemical performances.The optimized Na0.8MnO2comprising 69.9 wt%O'3 and 30.1 wt% P2 phase,exhibited relatively balanced specific capacity,Coulombic efficiency and cycle stability.Specifically,it achieved a high specific capacity of 128.9 mAh·g-1with an initia Coulombic efficiency of 98.2%in half-cell configuration The Na0.8MnO2// hard carbon full cell also achieved a high specific capacity of 126.7 mAh·g-1with an initia Coulombic efficiency of 98.9%.Moreover,the capacity fading mechanism was revealed by combining in-situ and ex-situ X-ray diffraction.The findings of this study provide theoretical guidance for further modification design of Mnbased layered cathodes.

关键词： Sodium-ion batteries Cathode materials Mn-based layered oxides P2/O′3 composites

Fabrication and Photoluminescence Properties of Hexagonal Micro-pyramids ZnO Powders by Combustion Synthesis

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Journal of Wuhan University of Technology(Materials Science) 2011年第4期26卷 700-702页

作者：陈皑张英 Zhoushan Institute of Calibration and Testing for Qualitative and Technical supervision

The ZnO powder with hexagonal-pyramids structure was prepared by the low-temperature combustion process. Ammonium acetate was used as the fuels, whereas zinc nitrate acted as the oxidant. The effect of different ration between fuel and oxidant on the morphology and photoluminescence （PL） characteristic was studied. The formation of hexagonal-pyramids structure was discussed. The optimum preparing parameter for fine morphology is that the ratio of zinc nitrate and ammonium acetate is 1：5, and ignition temperature is 500 ℃. The PL measurement indicates all samples have the strong blue and yellow emission peak. The changes of surface energy of the polar surfaces result in the formation of micro-pyramids structure.

关键词： ZnO combustion synthesis PL morphology

Evaluating the performance and influencing factors of three portable black carbon monitors for field measurement

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Journal of Environmental Sciences 2024年第5期139卷 320-333页

作者： Liqing Wu Yicheng Shen Fei Che Yuzhe Zhang Jian Gao Chong Wang State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China Jinan Ecological Environmental Protection Grid-Based supervision Center Jinan 250013China

Black carbon(BC)is associated with adverse human health and climate change.Mapping BC spatial distribution imperatively requires low-cost and portable devices.Several portable BC monitors are commercially available,but their accuracy and reliability are not always satisfactory during continuous field observation.This study evaluated three models of portable black carbon monitors,C12,MA350 and DST,and investigates the factors that affect their performance.The monitors were tested in urban Beijing,where portable devices running for one month alongside a regular-size reference aethalometer AE33.The study considers several factors that could influence the monitors'performance,including ambient weather,aerosol composition,loading artifacts,and built-in algorithms.The results show that MA350and DST present considerable discrepancies to the reference instrument,mainly occurring at lower concentrations(0-500 ng/m^(3))and higher concentrations(2500-8000 ng/m^(3)),respectively.These discrepancies were likely caused by the anomalous noise of MA350 and the loading artifacts of DST.The study also suggests that the ambient environment has limited influence on the monitors'performance,but loading artifacts and accompanying compensation algorithms can result in unrealistic data.Based on the evaluation,the study suggests that C12 is the best choice for unsupervised field measurement,DST should be used in scenarios where frequent maintenance is available,and MA350 is suitable for research purposes with post-processing applicable.The study highlights the importance of assigning portable BC monitors to appropriate applications and the need for optimized real-time compensation algorithms.

关键词： Black carbon Aethalometer Loading artifact Performance evaluation Portable device

Interaction Between Ustilaginoidea virens and Rice and Its Sustainable Control

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Rice science 2024年第3期31卷 269-284页

作者： ZHANG Fengmin CAO Zhenzhen ZHENG Xin HE Yuntao CHEN Mingxue LIN Xiaoyan Rice Product Quality Inspection&supervision Testing Center of Ministry of Agriculture and Rural Affairs China National Rice Research InstituteHangzhou 310006China

Ustilaginoidea virens is a common rice pathogen that can easily lead to a decline in rice quality and the production of toxins pose potential risks to human health.In this review,we present a comprehensive literature review of research since the discovery of rice false smut.We provide a comprehensive and,at times,critical overview of the main results and findings from related research,and propose future research directions.Firstly,we delve into the interaction between U.virens and rice,including the regulation of transcription factors,the process of U.virens infecting rice panicles,and the plant immune response caused by rice infection.Following that,we discuss the identification and characterization of mycotoxins produced by the pathogenic fungus,as well as strategies for disease management.We emphasize the importance of comprehensive agricultural prevention and control methods for the sustainable management of U.virens.This knowledge will update our understanding of the interaction between U.virens and rice plants,offering a valuable perspective for those interested in U.virens.

关键词： rice false smut flower-specific infection mycotoxin food safety plant disease

Directional amine-based solvent extraction for simultaneous enhanced water recovery,salt separation and effective descaling from hypersaline brines

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Frontiers of Environmental Science & Engineering 2024年第3期18卷 83-92页

作者： Yuyao Zhang Litao Jia Jin Zhao Xuming Liu Shuyu Dong Chuanyang Liu Yuanyuan Cui Shougang Research Institute of Technology Beijing 100043China Research Center of Environmental Technology in Water Pollution Source Identification and Precise supervision School of EnvironmentTsinghua UniversityBeijing 100084China

The feasibility of simultaneous water recovery,salt separation and effective descaling of hypersaline brine was investigated by diisopropylamine(DIPA)-based directional solvent extraction(DSE),using diluted/concentrated seawater with initial saline concentration range of 12–237 g/L at extraction temperatures of 5 and 15℃,respectively.The water recovery shows an obvious boundary at saline concentration of 115 g/L under dual effect of specific water extraction efficiency and extraction cycles.High Cl^(–) ion concentration in product water is in sharp contrast to the nearly complete removal of SO_(4)^(2–)and hardness ions,indicating that DIPA-based DSE process indeed achieved efficient separation and purification of Cl^(–) ion from hypersaline brines.Especially,the radical precipitation of Mg^(2+)and Ca^(2+)ions in form of Mg(OH)_(2)and CaCO_(3)demonstrates effective descaling potential,although it leads to more DIPA residues in dewatered raffinate than product water.Moreover,an exponential correlation between the Cl^(–) removal efficiency and specific water extraction efficiency further reveals the intrinsic relationship of water extraction process and transfer of Cl^(–) ion to the product water.Overall,the study provides a novel approach for integrating the water recovery and separation of Cl^(–) ion from ultra-high-salinity brines with radical precipitation of Mg^(2+)and Ca^(2+) ions in one step.

关键词： Hypersaline brines Directional solvent extraction Salt separation Ca^(2+)and Mg^(2+)descaling

Control of Iodine Deficiency Disorders Following 10-Year Universal Salt Iodization in Hebei Province of China

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Biomedical and Environmental Sciences 2009年第6期22卷 472-479页

作者： SHENG-MIN LV LI-JUN XIE RONG-HUA ZHOU ZHEN-SHUI CHONG LI-HUI JIA JING MA JUN ZHAO DONG XU Hebei Provincial Centre for Disease Control and Prevention Shijiazhuang 050021 Hebei China Hebei Provincial Bureau for Health supervision Shijiazhuang 050071 Hebei China

Objective To evaluate the effectiveness of universal salt iodization （USI） for the control of IDD in Hebei province since it was implemented in 1995, identify the problems currently encountered in the implementation of USI and provide practical proposals for addressing these problems. Methods Probability proportionate to size sampling （PPS） was employed in the surveillance of IDD, for which a total of 1200 school children aged 8-10 years were randomly selected from 30 counties around the whole province during each IDD survey. The iodine content of salt was determined quantitatively with the titration method. The iodine content of urinary samples was measured by the method of ammonium persulfate oxidation. Results The coverage of iodized salt increased from 65.0% in 1995 to 98.0% in 1999, then decreased to 88.1% in 2005 which was below the national standard of 90%. The median urinary iodine of children aged 8-10 years varied between 160.1 μg/L and 307.4 μg/L, which was above the national standard. The proportion of urinary samples with iodine content above 300 lag/L was over 30% in 2005, implying exorbitant iodine nutrition among the children. The goiter rate （TGR） among children aged 8-10 years dropped from 11.8% in 1995 to 2.7% in 2005, indicating that the spread of endemic goiter was under control. Conclusion Preliminary elimination of IDD was achieved by USI in Hebei province. Nevertheless, some problems still existed in USI such as non-iodized salt competition, over iodization and un-standardized iodization. In order to address these problems, the management and supervision of salt market needs to be strengthened to prevent non-iodized salt from reaching households; updating equipment and modifying techniques are also necessary to ensure the quality of iodized salt; to clarify the causes of excessive urinary iodine content, the various sources of iodine from the diet need to be investigated in the future.

关键词： Iodine deficiency disorders （IDD） Universal salt iodization （USI） Assessment Effectiveness

Noncovalent cross-linked engineering hydrogel with low hysteresis and high sensitivity for flexible self-powered electronics

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Journal of Energy Chemistry 2024年第7期94卷 136-147页

作者： Hang Yuan Shaowei Han Jia Wei Songwei Li Peipei Yang Hao-Yang Mi Chuntai Liu Changyu Shen National Engineering Research Center for Advanced Polymer Processing Technology Key Laboratory of Materials Processing and Mold(Ministry of Education)Zhengzhou UniversityZhengzhou450002HenanChina Yunnan TobaccoQuality Inspection&supervision Station Kunming 650106YunnanChina

In this study,the hydrogel network was reinforced by covalent-like hydrogen bonding,and the strong binding ability of boron-nitrogen coordination served as the main driving force.Among them,acrylamide(AM)and 3-acrylamidophenylboronic acid(AAPBA)were the main body,and the numerous hydroxyl groups in the trehalose(Treh)molecule and other polymer groups formed strong hydrogen bonding interactions to improve the mechanical properties of the PAM/PAAPBA/Treh(PAAT)hydrogel and ensured the simplicity of the synthesis process.The hydrogel possessed high strain at break(1239%),stress(64.7 kPa),low hysteresis(100%to 500%strain,corresponding to dissipation energy from 1.37 to 7.80 kJ/m^(3)),and outstanding cycling stability(retained more than 90%of maximum stress after 200 ten-sile cycles).By integrating carbon nanotubes(CNTs)into PAAT hydrogel(PAATC),the PAATC hydrogel with excellent strain response performance was successfully constructed.The PAATC conductive hydro-gel exhibited high sensitivity(gauge factor(GF)=10.58 and sensitivity(S)=0.304 kPa^(-1)),wide strain response range(0.5%-1000%),fast response time(450 ms),and short recovery time(350 ms),excellent fatigue resistance,and strain response stability.Furthermore,the PAATC-based triboelectric nanogener-ator(TENG)displayed outstanding energy harvesting performance,which shows its potential for appli-cation in self-powered electronic devices.

关键词： Low hysteresis Covalent-like hydrogen bonding Boron-nitrogen coordination Hydrogel sensor Triboelectric nanogenerator

Carbon dots-derived three-dimensional-ordered macroporous host with high penetrability and catalytic activity for LSBs under lean electrolyte

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Rare Metals 2024年第6期43卷 2560-2573页

作者： Jiao-Zi Duan Hua-Yu Pei Quan Yang Xue Li Xin Ba Xue Yong Jun-Ling Guo Si-Yu Lu Green Catalysis Center College of ChemistryZhengzhou University Country State Center for International Cooperation On Designer Low-Carbon & Environmental Materials School of Materials Science and EngineeringZhengzhou University Hubei Institute of Quality supervision Inspection Department of Chemistry University of Sheffield

The practical energy density of lithium-sulfur batteries（LSBs） is seriously limited by the high electrolyte-to-sulfur ratios（E/S）.The E/S can be reduced by employing hosts with easy-to-infiltrate structure that ensures the uniform distribution of a lean electrolyte and high catalytic activity that can suppress "shuttle effect" via accelerating the slow conversion of soluble poly sulfides to insoluble sulfides.Among the easy-to-infiltrate structures,the three-dimensional-ordered macroporous（3DOM）structure is easier to scale preparation and more suitable for the existing industrial processes.However,it is difficult to obtain the 3DOM with（1） high penetrability due to the high viscosity of frequently-used organic polymer precursors and（2） high catalytic activity due to the low confinement effect,meaning that uniformly dispersed small-sized catalytic materials are difficult to load on 3DOM.Herein,using carbon dots（CDs） with both organic and inorganic properties as a precursor and aggregation limiting agent,a 3DOM host with high penetrability and homodispersed Ni particles of small sizes（Ni-CDs-3DOM）was synthesized.In this host:（1） CDs precursor with suitable viscosity can improve the penetrability.（2） CDs can effectively inhibit the agglomeration of Ni particles.（3） Uniformly dispersed small-size Ni particles offer high-efficiency catalytic activity toward sulfur reactions.Consequently,the Ni-CDs-3DOM/sulfur cathode exhibits high sulfur utilization and stable cycling performance even under high sulfur loading(5.5 mg·cm-1) and low E/S(6.5 μl·mg-1).This work indicates the usefulness of CDs in constructing hosts for LSBs with high energy density.

关键词： Lithium–sulfur batteries Carbon dots Catalytic action Easy-to-infiltrate structure Lean electrolyte

Nanocrystalline WSe_(2)excels at high-performance anode for Na storage via a facile one-pot hydrothermal method

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Tungsten 2024年第1期6卷 248-258页

作者： Hai-Yan Zou Lei Fang Gang Yu Dong Wang State Key Laboratory of Chem/Bio-Sensing and Chemometrics Provincial Hunan Key Laboratory for Graphene Materials and DevicesCollege of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Changxing County Quality and Technology supervision and Testing Center Huzhou 313100China

For the next large-scale energy storage systems,sodium-ion batteries(SIBs)with excellent electrochemical performance are promising.However,the exploration of anode materials with high specific capacity,fascinating cycling stability and rate capability is still restricted.Among transition metal dichalcogenides(TMDs),tungsten diselenide(WSe_(2))has been regarded as an effective anode material for SIBs and has been extensively studied,due to high theoretical capacity and unique twodimensional layered structure.Herein,nanocrystalline WSe_(2)is prepared by a facile one-pot hydrothermal method.Compared with the micro-scale WSe_(2),benefiting from the high specific surface area of highly ordered nano-flake structures and short ion/electron transport paths,nanocrystalline WSe_(2)shows excellent electrochemical performance in Na storage.After 1000 cycles at a current density of 2 A·g^(-1),a high specific capacity of 264.4 mA·h·g^(-1)is still maintained.The full cell matched with the Na_(3)V_(2)(PO_(4))_(3) cathode can deliver an excellent reversible specific capacity of 196.5 mA·h·g^(-1)after 100 cycles at 0.5 A·g^(-1).

关键词： Tungsten diselenide Transition metal dichalcogenides Hydrothermal Sodium-ion batteries Layered structure