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Strong and tough chitin hydrogel constructed by dehydration and rehydration strategy

Nano Research 2024年第9期17卷 8192-8199页

作者： Rui-Rui liu Li-Bo mao Shu-Hong Yu Division of Nanomaterials and Chemistry Hefei National Research Center for Physical Sciences at the MicroscaleDepartment of ChemistryInstitute of Biomimetic Materials and ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsUniversity of Science and Technology of ChinaHefei 230026China Institute of Innovative Materials Department of Materials Science and EngineeringDepartment of ChemistrySouthern University of Science and TechnologyShenzhen 518055China

As a renewable,biocompatible,biodegradable soft material,chitin hydrogels have better advantages in stability,antibacterial activity,antifouling,cost,immunogenicity,and so on than most polymer ***,compared with other widely used polymer hydrogels with high strength and toughness,the practical applications of chitin-based hydrogels have been limited by their weak mechanical properties,such as cartilage repair and meniscus ***,we present the design and fabrication of chitin hydrogels with excellent mechanical strength and toughness by a dehydration and rehydration *** sequential dehydration and rehydration processes,the crystalline domains in the chitin hydrogels can be properly *** optimized crystallinity,the elastic modulus of the chitin hydrogels exceeds all previously reported values,and the fracture toughness is even comparable to some synthetic polymer hydrogels,while maintaining a high-water-content of about 80 wt.%.At the same water content,the mechanical properties of the chitin hydrogels are positively correlated with the hydrogel crystallinity,which proves that the change of mechanical properties of hydrogels is not simply dependent on weight *** hydrogels can be further strengthened by incorporating other biopolymers that are intrinsically weak,which makes the hydrogels promising for applications in fields such as cartilage repair and meniscus ***,the hydrogels enable loading and release of water-soluble and poorly water-soluble *** highly extendable strengthening and toughening strategy of chitin and chitin-based biopolymer hydrogels paves the way for their widely applications.

关键词： chitin hydrogel crystallinity rehydration chemical transformation strong and tough

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Circulation Background and Genesis Mechanism of a Cold Vortex over the Tibetan Plateau during Late April 2018

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Advances in Atmospheric Sciences 2024年第6期41卷 1201-1216页

作者： Duming GAO Jiangyu mao Guoxiong WU Yimin liu State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province Institute of Plateau MeteorologyChina Meteorological AdministrationChengdu 610072China Chinese Academy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China

A cold vortex occurred over the northeastern Tibetan Plateau(TP)on 27 April 2018 and subsequently brought excessive rainfall to the spring farming area in southern China when moving *** study investigates the genesis mechanism of the cold TP vortex(TPV)by diagnosing reanalysis data and conducting numerical *** demonstrate that the cold TPV was generated in a highly baroclinic environment with significant contributions of positive potential vorticity(PV)forcing from the tropopause and diurnal thermodynamic impact from the *** a positive PV anomaly in the lower stratosphere moved towards the TP,the PV forcing at the tropopause pushed the tropospheric isentropic surfaces upward,forming isentropic-isplacement ascent and reducing static stability over the *** descent of the tropopause over the TP also produced a tropopause folding over the northeastern TP associated with a narrow high-PV column intruding downwards over the TPV genesis site,resulting in ascending air in the free ***,in conjunction with the descending air in the valley area during the night,produced air stretching just at the TPV genesis *** the surface cooling at night increased the surface static stability,the aforementioned vertical air-stretching thus converted the produced static stability to vertical ***,the cold TPV was generated over the valley at night.

关键词： tropopause PV forcing air column stretching static stability vertical vorticity

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Gene editing in plants:progress and challenges

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National Science Review 2019年第3期6卷 421-437页

作者： Yanfei mao Jose Ramon Botella Yaoguang liu Jian-Kang Zhu Shanghai Center for Plant Stress Biology CAS Center of Excellence in Molecular Plant Sciences Chinese Academy of Sciences School of Agriculture and Food Sciences University of Queensland State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources College of Life Sciences South China Agricultural University Department of Horticulture and Landscape Architecture Purdue University

The clustered regularly interspaced short palindromic repeat(CRISPR)-associated protein 9(Cas9)genome editing system is a powerful tool for targeted gene modifications in a wide range of species,including plants. Over the last few years, this system has revolutionized the way scientists perform genetic studies and crop breeding, due to its simplicity, flexibility, consistency and high efficiency. Considerable progress has been made in optimizing CRISPR/Cas9 systems in plants, particularly for targeted gene mutagenesis. However, there are still a number of important challenges ahead, including methods for the efficient delivery of CRISPR and other editing tools to most plants, and more effective strategies for sequence knock-ins and replacements. We provide our viewpoint on the goals, potential concerns and future challenges for the development and application of plant genome editing tools.

关键词： CRISPR Cas9 genome editing base editing gene targeting crop breeding

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Tuning desolvation kinetics of in-situ weakly solvating polyacetal electrolytes for dendrite-free lithium metal batteries

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Journal of Energy Chemistry 2023年第4期79卷 340-347页

作者： Peng Wen Yimin liu Jinyan mao Xiaotong liu Weiping Li Yang Ren Yang Zhou Fei Shao mao Chen Jun Lin Xinrong Lin Key Laboratory of Medicinal Chemistry for Natural Resource Ministry of Education and Yunnan ProvinceSchool of Chemical Science and TechnologyYunnan UniversityKunming 650091YunnanChina State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200433China

The host structure of polymers significantly influences ion transport and interfacial stability of electrolytes,dictating battery cycle life and safety for solid-state lithium metal *** promising properties of ethylene oxide-based electrolytes,their typical clamp-like coordination geometry leads to crowd solvation sheath and overly strong interactions between Li^(+)and electrolytes,rendering difficult dissociation of Li+and unfavorable solid electrolyte interface(SEI).Herein,we explore weakly solvating characteristics of polyacetal electrolytes owing to their alternately changing intervals between–O–coordinating sites in the main *** structural asymmetry leads to unique distorted helical solvation sheath,and can effectively reduce Li^(+)-electrolyte binding and tune Li^(+)desolvation kinetics in the insitu formed polymer electrolytes,yielding anion-derived SEI and dendrite-free Li *** with photoinitiated cationic ring-opening polymerization,polyacetal electrolytes can be instantly formed within 5 min at the surface of electrode,with high segmental chain motion and well adapted *** in-situ polyacetal electrolytes enabled more than 1300-h of stable lithium electrodeposition and prolonged cyclability over 200 cycles in solid-state batteries at ambient temperatures,demonstrating the vital role of molecular structure in changing solvating behavior and Li deposition stability for high-performance electrolytes.

关键词： Polymer electrolyte In-situ photoinitiated polymerization Weakly solvating effect Polyacetal Lithium electrodeposition

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Research on port ecological suitability evaluation index system and evaluation model

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Frontiers of Structural and Civil Engineering 2015年第1期9卷 65-70页

作者： Yaofeng XIE Xia LV Ru liu liuyan mao Xiaoxi liu Department of Harbor and Waterway Engineering Southeast University Nanjing 210096 China Guangdong Institute of Technology Guangzhou 510800 China

Along with the rapid development of port building, the negative impacts of port＇s construction and operation on the coastline ecosystem are also increasingly strong. Therefore, it＇s urgent to establish a scientific and complete system of port ecological suitability evaluation. This paper pointed out the characteristics of port ecological effects and the principles of selecting evaluation index, and used the ＂pressure-state-response （PSR）＂ model to analysis the various pressures on the environment caused by port construction and operation, and the system＇s response. On this basis, we constructed the port ecological suitability evaluation index. This model used the combination of qualitative and quantitative analytic hierarchy process, to meet the multi-level, multi-objective characteristics of evaluation index system. The evaluation index system and evaluation model can be used to analysis the ecological suitability of port projects comprehensively and have some guiding significance to the port ecological suitability evaluation.

关键词： port ecological suitability press-state-response (PSR) model evaluation index system

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A whispering-gallery scanning microprobe for Raman spectroscopy and imaging

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Light(Science & Applications) 2023年第11期12卷 2402-2410页

作者： Wenbo mao Yihang Li Xuefeng Jiang Zhiwen liu Lan Yang Department of Electrical and Systems Engineering Washington UniversitySt LouisMO 63130USA Department of Electrical Engineering Pennsylvania State UniversityUniversity ParkPA 16802USA

Optical whispering-gallery-mode microsensors are a promising platform for many applications,such as biomedical monitoring,magnetic sensing,and vibration ***,like many other micro/nanosensors,they cannot simultaneously have two critical properties–ultrahigh sensitivity and large detection area,which are desired for most sensing ***,we report a novel scanning whispering-gallery-mode microprobe optimized for both features and demonstrate enhanced Raman spectroscopy,providing high-specificity information on molecular fingerprints that are important for numerous sensing *** the superiorities of whispering-gallery modes and nanoplasmonics,the microprobe exhibits a two-orders-of-magnitude sensitivity improvement over traditional plasmonics-only enhancement;this leads to molecular detection demonstrated with stronger target signals but less optical power required than surface-enhanced-Raman-spectroscopy ***,the scanning microprobe greatly expands the effective detection area and realizes two-dimensional micron-resolution Raman imaging of molecular *** versatile and ultrasensitive scanning microprobe configuration will thus benefit material characterization,chemical imaging,and quantum-enhanced sensing.

关键词： microprobe scanning spectroscopy

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Effect of copper precursors on CO oxidation catalyzed by CuO-CeO_(2) prepared by solvothermal method

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Journal of Rare Earths 2023年第12期41卷 1953-1962,I0005页

作者： Wen Jin Yanmin liu Jun Yu Xiaoming Guo Dongsen mao School of Chemical and Environmental Engineering Shanghai Institute of TechnologyShanghai201418China

In this paper,the CuO-CeO_(2) catalyst was prepared by a direct solvothermal *** effects of different copper salt precursors(copper nitrate,copper acetate,copper sulfate) on the catalytic performa nce of the prepared catalyst fo r CO oxidation were *** physical and chemical properties of the prepared catalysts were characterized by X-ray diffraction(XRD),Raman spectroscopy,N_(2)physical adsorption,inductively coupled plasma-atomic emission spectrometry(ICP-AES),X-ray photoelectron spectroscopy(XPS),temperature-programmed desorption analysis of CO(CO-TPD),in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTs),and temperature-programmed reduction with H_(2)(H_(2)-TPR).The results show that the CuO-CeO_(2)catalyst prepared with copper acetate as precursor(CC-A) exhibits the best catalytic activity for CO oxidation at low temperatures,with T50and T90values of 62 and 78℃ respectively,which is mainly attributed to its large specific surface area,pore volume,CO adsorption capacity,and large amount and strong reactivity of surface ***,the CuO-CeO_(2) catalyst prepared with copper nitrate as precursor(CC-N) displays better stability and resistance to water or CO_(2) poisoning than CC-A.

关键词： Cuo-CeO_(2) Solvothermal method Copper precursor CO oxidation Rare earths

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Effects of initial particle gradation and rock content on crushing behaviors of weathered phyllite fills——A case of eastern Ankang section of Shiyan—Tianshui highway,China

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第2期12卷 269-278页

作者： Feifei liu Xuesong mao Yushuo Fan Linping Wu Wei Victor liu School of Highway Chang'an UniversityXi'anChina Shijiazhuang Transportation Survey and Design Institute ShijiazhuangChina Department of Civil and Environmental Engineering University of AlbertaEdmontonCanada

The objective of this paper is to investigate the effects of initial particle gradation and rock content on the crushing behavior(*** size before and after crushing) of weathered phyllite *** tests were conducted on weathered phyllite fills with rock contents of 35%,45%,55%,65% and 75%(by weight).First,the particle size distributions(PSDs) were observed before and after compaction,and then the particle breakage of weathered phyllite fills was analyzed by fractal *** fractal dimension was proposed to evaluate the effects of initial rock content and initial gradation on the particle *** was found that the fractal dimension method can well characterize the crushing behaviors of the weathered phyllite *** finer the fills were,the more they were *** is,after the first compaction,the relative fractal dimension of the weathered phyllite fills increased as the rock content increased,reaching the values of 0.013,0.016,0.024,0.037 and 0.08,*** the second compaction,these relative fractal dimension values,dominated by the initial particle gradation,became 0.059,0.072,0.052,0.095 and 0.118,*** conclusion,the weathered phyllite fills with 55% rock content exhibited the least breakage and were most suitable for filling the *** in this paper will provide significant guidance for the construction of weathered phyllite filling subgrade in future projects.

关键词： Weathered phyllite fills Crushing behavior Compaction test Fractal dimension Relative fractal dimension

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Examination on the wear process of polyformaldehyde gears under dry and lubricated conditions

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Friction 2021年第3期9卷 538-550页

作者： Guoda YU Huaiju liu Ken mao Caichao ZHU Zehua LU State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400030China School of Engineering the University of WarwickCoventry CV47ALUK

This study presents the results of detailed wear process examination on polyformaldehyde gears under both dry and lubricated conditions.A multi-purpose durability test rig was employed to study the wear performance of polyformaldehyde gear *** wear behaviors of polyformaldehyde gears under dry and oil-lubricated operating conditions were characterized via measurements of gear tooth surface micro-topography and tooth profile *** the dry running condition,a hump and a gully appear on the tooth surface in the pitch line area of the driving gear and the driven wheel,*** largest amount of wear was observed around the tooth root of the driving ***,the gear tooth wear pattern with lubrication is different from that under the dry running condition.

关键词： polyformaldehyde gear lubrication wear surface damage

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Metal nanozymes with multiple catalytic activities: regulating strategies and biological applications

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Rare Metals 2023年第9期42卷 2928-2948页

作者： Qi Yang Yuan-Yang mao Quan liu Wei-Wei He Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province Institute of Surface Micro and Nano MaterialsCollege of Chemical and Materials EngineeringXuchang UniversityXuchang461000China

Nanozymes with high enzyme-like catalytic activity have been recognized as promising alternatives for nature enzymes and exhibit great potentials in biodetection,disease diagnosis and treatment. Metal nanozyme is an important member of the nanozyme family. When metal nanozymes are controllably regulated by compositions,sizes, morphologies, crystal defects, surface states or stimulated by diversified external fields, they will acquire unique geometric and electronic structures and exhibit various physical/chemical properties in catalytic *** significant progress has been made in metal nanozymes, there is still large space for further improving the catalytic efficiency, developing the synthetic process for large-scale production, facilitating the clinical transformation and exploring the untapped *** at these issues, rational design of novel nanozymes for better applications and deeper understanding of catalytic mechanisms are urgently required. Accordingly,this review focuses on the recent advances on regulating strategies, catalytic mechanisms and relevant biological applications of metal nanozymes with multiple enzymelike performance. Furthermore, future perspectives are outlooked to inspire more attention and efforts on this interesting multi-disciplinary field.

关键词： Metal nanozymes Catalytic mechanism Regulating strategy Grain orientation Disease treatment

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