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Study on preparation and properties of CeO_2/epoxy resin composite coating on sintered NdFeB magnet

Journal of Rare Earths 2018年第5期36卷 544-551页

作者： Pengjie zhang Minggang Zhu Wei Li Guangqing Xu Xiulian Huang Xiaofei yi Jingwu Chen Yucheng Wu School of Materials Science and Engineering Hefei University of Technology Hefei 230009 China Central 1ran and Steel Research institute Beijing 100081 China State Key Laboratory of Rare Earth Permanent Magnet Materials (Earth-Panda Advance Magnetic Material Co. Ltd.) Hefei 231500 China School of Mechanical Engineering Hefei University of Technology Hefei 230009 China

The CeO2/epoxy resin composite coating was deposited on NdFeB substrate by cathode electrophoresis method for enhancing the anticorrosion and anti-wear performances. The morphologies and structures were characterized by a scanning electron microscope and an X-ray diffractometer. The micro hardness of the composite coating was evaluated by a microhardness tester. The corrosive behaviors of the coatings were studied by potentiodynamic polarization curve, electrochemical impedance spectroscopy and neutral salt spray tests. The concentration of CeO2 nanoparticles（NPs） in the electrophoresis bath was optimized according to the coating structures and anticorrosion performances. The results show that CeO2 NPs can enhance the microhardness of the composite coatings. Moreover, the nanoparticles disperse uniformly in the matrix when the concentration is lower than 30 g/L. The microhardness of CeO2/epoxy resin（30 g/L） composite coating is about 63% higher than that of the blank epoxy resin coating. And the NSS time of the CeO2/epoxy resin（30 g/L） composite coated sample can reach 1248 ***, the composite coatings possess no deteriorate influence on the magnetic properties of NdFeB substrates. The anticorrosion mechanisms of the composite coatings on the NdFeB substrate are deeply discussed.

关键词： Sintered NdFeB Epoxy resin CeO2 nanoparticle Corrosion resistance Rare earths

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In-situ coating and surface partial protonation co-promoting performance of single-crystal nickel-rich cathode in all-solid-state batteries

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Journal of Energy Chemistry 2024年第2期89卷 137-143,I0005页

作者： Maoyi yi Jie Li Mengran Wang Xinming Fan Bo Hong Zhian zhang Aonan Wang Yanqing Lai School of Metallurgy and Environment Central South UniversityChangsha 410083HunanChina Engineering Research Centre of Advanced Battery Materials The Ministry of EducationChangsha 410083HunanChina Hunan Province Key Laboratory of Nonferrous Value-Added Metallurgy Central South UniversityChangsha 410083HunanChina

The poor electrochemical performance of all-solid-state batteries(ASSBs),which is assemblied by Ni-rich cathode and poly(ethylene oxide)(PEO)-based electrolytes,can be attributed to unstable cathodic interface and poor crystal structure stability of Ni-rich *** coating strategies are previously employed to enhance the stability of the cathodic interface and crystal structure for Ni-rich ***,these methods can hardly achieve simplicity and high efficiency *** this work,polyacrylic acid(PAA)replaced traditional PVDF as a binder for cathode,which can achieve a uniform PAA-Li(LixPAA(0

关键词： Single-crystal LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2) In-situ coating PAA-Li Partial protonation

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Rod-like mesoporous silica nanoparticles facilitate oral drug delivery via enhanced permeation and retention effect in mucus

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Nano Research 2022年第10期15卷 9243-9252页

作者： Wenjuan Liu Luyu zhang Zirong Dong Kaiheng Liu Haisheng He yi Lu Wei Wu Jianping Qi School of Pharmacy Key Laboratory of Smart Drug Delivery of MOEFudan UniversityShanghai 201203China

The physiochemical characteristics of nanoparticles affect their in vitro and in vivo performance significantly,such as diameter,surface chemistry,and *** paper disclosed the effect of enhanced permeation and retention(EPR)in mucus caused by nanoparticle shape on improving oral *** spherical and rod-like mesoporous silica nanoparticles(MSNs)were used to evaluate shape effect of EPR in *** was loaded in MSNs as model *** in vitro release of fenofibrate from MSNs was dependent on nanoparticle shapes,but faster than that of raw *** drug release slowed down with the increase of aspect ratio due to longer channels in rod-like MSNs with higher aspect ***,in vivo study showed that the oral bioavailability of fenofibrate was the highest after loading in rod-like MSNs with aspect ratio of *** in vitro study of mechanisms revealed that superior mucus diffusion ability of rod-like MSNs with aspect ratio of 5 was conductive to higher ***,more rod-like MSNs with higher aspect ratio were able to diffuse into mucus and reside there compared to spherical and short counterparts,which demonstrated higher aspect ratio was beneficial to EPR effect of nanoparticles in *** study provides significant implication in rational oral drug carrier design.

关键词： mesoporous silica nanoparticles shape effect fenofibrate mucus layer enhanced permeation and retention effect

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Spatio-temporal variation of spring phenology in Tibetan Plateau and its linkage to climate change from 1982 to 2012

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Journal of Mountain Science 2016年第1期13卷 83-94页

作者： DING Ming-jun LI Lan-hui NIE Yong CHEN Qian zhang yi-li Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education and School of Geography and EnvironmentJiangxi Normal UniversityNanchang 330022China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China

The influence of climate change on vegetation phenology is a heated issue in current climate change *** used GIMMS-3g NDVI data to detect the spatio-temporal dynamics of the start of the growing season(SGS) over the Tibetan Plateau(TP) from 1982 to 2012 and to analyze its relationship with temperature and *** significant trend was observed in the SGS at the regional scale during the study period(R^2 = 0.03,P = 0.352).However,there were three time periods(1982-1999,1999-2008 and 2008-2012) with identifiable,distinctly different *** with a significant advancing trend were mainly scattered throughout the humid and semi-humid areas,whereas the regions with a significant delaying trend were mostly distributed throughout the semi-arid *** analysis showed that the response of the SGS to climate change varies *** SGS was significantly correlated with the spring temperature and the start of the thermal growth season(STGS) in the relatively humid *** increasing aridity,theimportance of the spring temperature for the SGS gradually ***,the influences of precipitation and winter temperature on the SGS were complicated across the plateau.

关键词： Spring phenology Spatial pattern Temporal variation Climate change CorrelationTibetan Plateau (TP)

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Quantification and influence factor analysis on total inward leakage of N95 respirators by simulating healthcare professional’s procedures

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Building Simulation 2024年第10期17卷 1731-1748页

作者： Linzhi Fu Jiazhen Guo Yu zhang Xiaohong Jing Lianhe Lu yi Wang Rongmeng Jiang Li Liu State Key Laboratory of Green Building Xi’an University of Architecture and TechnologyXi’an 710055China School of Resources Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Beijing Ditan Hospital Capital Medical UniversityBeijing 100015China School of Building Services Science and Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Department of Building Science Tsinghua UniversityBeijing 100084China Laboratory of Eco-Planning&Green Building Ministry of EducationTsinghua UniversityBeijing 100084China

Respiratory protection is critical to minimize airborne infection risk for healthcare *** main factor affecting infection risk in the medical scenario is leakage between the respirator and the healthcare workers’***,it is difficult to quantify the effectiveness of respirators due to the numerous influencing *** medical activities were simulated by the fitting test,and the inverse of the results were used to get the total inward leakage of respirators.114 subjects were divided according to gender,profession,age,risk area,and BMIs,participated in fitting test of four N95 *** result showed that the value range of total inward leakage for tested N95 respirators was between 0.50%and 2.39%.Flat-folded respirators were more prone to leakage than cup-shaped ones,so it was essential to account for the impact of respirator ***,this study found that gender and profession had no significant correlation with total inward *** medical procedures include bending,and turning head from side to side,or up and down,which had a significant influence on the protective efficacy of the N95 *** dimensions and BMI exerted a more pronounced influence on the protective efficacy of the N95 respirator,and they were in the *** personnels wore a well-fitting N95 respirator properly for excellent protection,reducing occurrence of nosocomial infections and occupational exposures,and optimizing respiratory protection strategies.

关键词： N95 respirator total inward leakage healthcare personnel fitting test

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Flexible and stable 3D lithium metal anodes based on self-standing MXene/COF frameworks for high-performance lithium-sulfur batteries

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Nano Research 2021年第10期14卷 3576-3584页

作者： Chuanliang Wei Yusheng Wang Yuchan zhang Liwen Tan yi Qian Yuan Tao Shenglin Xiong Jinkui Feng Research Center for Carbon Nanomaterials Key Laboratory for Liquid-Solid Structural Evolution&Processing of Materials(Ministry ofEducation)School of Materials Science and EngineeringShandong UniversityJinan 250061China School of Chemistry and Chemical Engineering Shandong UniversityJinan 250100China

Lithium metal(Li)is believed to be the ultimate anode for lithium-ion batteries(LIBs)owing to the advantages of high theoretical capacity,the lowest electrochemical potential,and light ***,issues such as uncontrollable growth of Li dendrites,large volume changes,high chemical reactivity,and unstable solid electrolyte interphase(SEI)hinder its rapid development and practical *** a stable and dendrite-free Li-metal anode is obtained by designing a flexible and freestanding MXene/COF framework for metallic ***-LZU1 microspheres are distributed among the MXene film *** COF-LZU1 microspheres as nucleation seeds can promote uniform Li nucleation by homogenizing the Li^(+)flux and lowering the nucleation barrier,finally resulting in dense and dendrite-free Li *** the regulation of the COF-LZU1 seeds,the Coulombic efficiency of the MXene/COF-LZU1 framework and electrochemical stability of corresponding symmetric cells are obviously ***-S full cells with the modified Li-metal anode and sulfurized polyacrylonitrile(S@PAN)cathode also exhibited a superior electrochemical performance.

关键词： MXene covalent organic framework(COF) dendrite-free lithium metal anode lithium sulfur battery sulfurized polyacrylonitrile

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In-situ observation of magnetization reversal process of Sm(Co,Cu,Fe,Zr)_z magnets with different Fe contents

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Rare Metals 2020年第3期39卷 250-255页

作者： Shuo Wu Dong-Tao zhang Ming Yue yun-Qiao Wang Zhi-Feng Shang Dan Wu Jing-Ming Liang College of Materials Science and Engineering Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing100124China

Sm(Co,Cu,Fe,Zr)z magnets have drawn much attention for high-temperature applications due to their high Curie temperature,strong corrosion resistance and thermal *** effect of increasing Fe content on the distribution of elements and squareness(Sr)of demagnetization curves were investigated for two kinds of magnets with different nominal compositions of Sm(CobalFe0.15-Cu0.07Zr0.03)7.8 and Sm(CobalFe0.28Cu0.07Zr0.03)6.6 in this *** magnetic properties of the magnets with higher Fe content fluctuate greatly after different solution treatments,indicating that they are more sensitive to the process *** increase in Fe content can obviously enhance the cellular phase ***,inhomogeneous Cu distribution is observed in the Sm(CobalFe0.28-Cu0.07Zr0.03)6.6 magnet,resulting in the different cellular structures and corresponding magnetic domain patterns in different regions in the inner ***,the lower Cu content regions are responsible for the wider magnetic domain,which have weaker resistance to applied magnetic *** a result,Sr of demagnetization curve decreases with the increase in Fe content due to the inhomogeneous Cu distribution,which was confirmed by in-situ observation of electron probe micro-analyzer(EPMA)and magneto-optical Kerr optical microscope(MOKE).

关键词： Sm(Co,Cu,Fe,Zr)_z magnets Cu distribution Microstructure Magnetic properties Magnetic domain Squareness

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Synthesis, Characterization, Polymerization of Optically Active Terminal Epoxides and Episulfides Bearing Bulky Groups

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Chemical Research in Chinese Universities 2013年第2期29卷 239-244页

作者： SUN yun-kai zhang Jin LIU Hui-jun HE Li GONG Hang YANG Nian-fa Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education College of Chemistry Xiangtan University Xiangtan 411105 P. R. China School of Chemistry and Chemical Engineering University of South China Hengyang 421001 P. R. China

A simple and efficient protocol was developed for the syntheses of optically active epoxides（2a--2d） via the reactions of epichlorohydrin with organometallic reagents with steric hindrance at low temperature. On this basis, episulfides（3a--3d） were obtained with high e.e. values by the reaction of the corresponding epoxides with NH4SCN. The configuration of thiiranes was opposite to that of the corresponding epoxides. Then, epoxides 2a--2d were anionically polymerized and the poly-R-2a（or poly-S-2a） was proved to keep a stable one-handed helical conforma- tion in solution. The oligomers[degree of polymerization（DP）=2--5] were obtained when the thiiranes（3a, 3b and 3c） were used to polymerize.

关键词： Optical activity Epoxide Episulfide One-handed helicity

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Mechanism of dibenzofuran hydrodeoxygenation on the Ni(1 1 1)surface

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Chinese Journal of Chemical Engineering 2021年第7期34卷 204-210页

作者： Zi-Zheng Xie Meng zhang Xing-Bao Wang Liang Guo Zhen-yi Du Wen-ying Li State Key Laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyKey Laboratory of Coal Science and Technology(Taiyuan University of Technology)Ministry of EducationTaiyuan 030024China

The low-temperature coal tar contains a considerable number of oxygen-containing compounds,which results in poor *** catalytic hydrodeoxygenation of oxygen-containing compound to an added-value chemical compound is one of the most efficient methods to upgrade coal *** this study,density functional theory calculations are employed to assess and analyze in detail the hydrodeoxygenation of dibenzofuran,as a model compound of coal tar,on the Ni(111)*** obtained results indicate that dibenzofuran can be firstly hydrogenated to tetra hy d rod i be nzofura n and *** five-membered-ring opening reaction of tetrahydrodibenzofuran is more straightforward than that of hexahydrodibenzofuran(Ea=0.71 eV vs.1.66 eV).Then,both pathways generate an intermediate 2-cyclohexylphenoxy *** part of 2-cyclohexylphenoxy is hydrogenated to 2-cyclohexylphenol and consecutively hydrogenated to cyclohexylcyclohexanol,and another part is directly hydrogenated to *** hydrogenated intermediates of2-cyclohexylphenol have higher deoxygenation barriers than 2-cyclohexylphenol and cyclohexylcy *** the hydrogenation process of cyclohexylcyclohexanone to cyclohexylcyclohexanol,the intermediate 26,formed by adding H to O atom of cyclohexylcyclohexanone,exhibits the lowest deoxygenation barrier of 1.08 *** hydrogen coverage may promote the hydrogenation of tetrahydrodibenzofuran,hexahydrodibenzofuran,and intermediate 26 to generate dodecahydrodibenzofuran and *** dibenzofuran hydrodeoxygenation reaction mechanism corroborates well with previous experimental results and provides a theoretical basis for further optimization of the design of nickel-based catalysts.

关键词： Oxygen-containing compound Hydrogenation Deoxygenation Catalysis Computational chemistry

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Facile Construction of Synergistic β-Glucosidase and Cellulase Sequential Co-immobilization System for Enhanced Biomass Conversion

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Chinese Journal of Polymer Science 2020年第12期38卷 1277-1285页

作者： Guan Wang Kai zhang Jia-yi Xin Chang-Wen Zhao Yu-Hong Ma Wan-Tai Yang State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China Beijing Laboratory of Biomedical Materials Beijing University of Chemical TechnologyBeijing 100029China Beijing Advanced Innovation Centre for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China Key Laboratory of Carbon Fiber and Functional Polymers Ministry of EducationBeijing University of Chemical TechnologyBeijing 100029China

Converting renewable cellulose into glucose via cellulase catalysis for further production of biofuel has been recognized as one of the most promising ways for solving energy ***,the hydrolysis performance of immobilized cellulase was not satisfactory for practical application due to the reduced catalytic efficiency and lack of β-glucosidase(BG)component in ***,a facile method was developed to sequentially co-immobilize BG and cellulase by polymeric microparticles with hierarchical *** this strategy,BG was firstly entrapped into the cross-linked poly(ethylene glycol)(PEG)microparticles via inverse emulsion polymerization initiated by isopropyl thioxanthone(ITX)under the irradiation of visible light,leaving the formed ITX semi-pinacol(ITXSP)dormant groups on surface of BG-loaded microparticles,which could be further activated by visible light irradiation and initiated a graft polymerization to introduce poly(acrylic acid)(PAA)brush on the PEG *** that,cellulase was covalently bonded on the PAA chains via carbodiimide *** synergic effect of BG and cellulase was verified in the dual enzyme immobilization system,which led to a better stability at a wide range of temperature and pH than free *** dual enzymes system exhibited excellent reusability,which could retain 75%and 57%of the initial activity after 10 cycles of hydrolysis of carboxyl methyl cellulose and 5 cycles of hydrolysis of filter paper,respectively,indicative of the potential in biofuel areas in a cost-effective manner.

关键词： Visible light Grafting polymerization Enzyme immobilization Cellulase

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