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Changes in Global Vegetation Distribution and Carbon Fluxes in Response to Global Warming:Simulated Results from IAP-DGVM in CAS-ESM2

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Advances in Atmospheric Sciences 2022年第8期39卷 1285-1298,I0002-I0010页

作者： Xiaofei GAO Jiawen ZHU Xiaodong ZENG Minghua ZHANG Yongjiu DAI Duoying JI He ZHANG International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China School of Marine and Atmospheric Sciences Stony Brook UniversityNY 11790USA School of Atmospheric Sciences Sun Yat-Sen UniversityGuangzhou 510275China College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875China

Terrestrial ecosystems are an important part of Earth systems,and they are undergoing remarkable changes in response to global warming.This study investigates the response of the terrestrial vegetation distribution and carbon fluxes to global warming by using the new dynamic global vegetation model in the second version of the Chinese Academy of Sciences(CAS)Earth System Model(CAS-ESM2).We conducted two sets of simulations,a present-day simulation and a future simulation,which were forced by the present-day climate during 1981-2000 and the future climate during 2081-2100,respectively,as derived from RCP8.5 outputs in CMIP5.CO_(2)concentration is kept constant in all simulations to isolate CO_(2)-fertilization effects.The results show an overall increase in vegetation coverage in response to global warming,which is the net result of the greening in the mid-high latitudes and the browning in the tropics.The results also show an enhancement in carbon fluxes in response to global warming,including gross primary productivity,net primary productivity,and autotrophic respiration.We found that the changes in vegetation coverage were significantly correlated with changes in surface air temperature,reflecting the dominant role of temperature,while the changes in carbon fluxes were caused by the combined effects of leaf area index,temperature,and precipitation.This study applies the CAS-ESM2 to investigate the response of terrestrial ecosystems to climate warming.Even though the interpretation of the results is limited by isolating CO_(2)-fertilization effects,this application is still beneficial for adding to our understanding of vegetation processes and to further improve upon model parameterizations.

关键词： global warming vegetation distribution carbon flux leaf area index surface air temperature

Experimental investigation on hard rock fragmentation of inserted tooth cutter using a newly designed indentation testing apparatus

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International Journal of Mining Science and Technology 2022年第3期32卷 459-470页

作者： Jiuqun Zou Weihao Yang Tao Zhang xiaofei Wang Min gao School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan 232001China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China School of Transportation and Civil Engineering Nantong UniversityNantong 226000China

This investigation aims to explore the effects of stress conditions and rock cutting rates on hard rock fragmentation through indentation tests on a newly designed triaxial testing apparatus.This apparatus was designed to realize a triaxial loading and indentation test of cylindrical specimens using inserted tooth cutter.The boreability and crushing efficiency of granite rock was investigated by analyzing the change rules of the thrusting force,penetration depth,characteristics of chippings and failure patterns.Several quantitative indexes were used to evaluate rock boreability in this investigation.The granite rock samples all had a chiselled pit and a crushed rock core.Under initial stress conditions,only flat-shape chippings were stripped from the rock surface when the thrusting force reached 20 kN.The rock cutting special energy had a close correlation with the initial stress conditions and inserted tooth shape.Moreover,a thrusting force prediction model was proposed in this paper.The contribution of this study is that for the first time the influence mechanism of the initial triaxial stress conditions on rock fragmentation is investigated using an inserted tooth and the newly designed testing apparatus.This study has a crucial importance for practical underground hard rock crushing in geoengineering.

关键词： Hard rock indentation test Hard rock fragmentation Triaxial confined conditions New triaxial testing apparatus Inserted tooth cutter Cylindrical rock specimens

Ecological damage of submerged macrophyte Myriophyllum spicatum by cell extracts from microcystin(MC)-and non-MC-producing cyanobacteria,Microcystis

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Journal of Oceanology and Limnology 2022年第5期40卷 1732-1749页

作者： Yunni gao Hui YANG Xiaofei GAO Mei LI Man ZHANG Jing DONG Jingxiao ZHANG Longfei LI Xuejun LI Michele A BURFORD Engineering Lab of Henan Province for Aquatic Animal Disease Control Engineering Technology Research Center of Henan Province for Aquatic Animal CultivationCollege of FisheriesHenan Normal UniversityXinxiang 453007China Australian Rivers Institute Griffi th UniversityNathanQueensland 4111Australia

To explore how decomposed Microcystis-dominant cyanobacterial blooms affect submerged macrophytes,the submerged plant Myriophyllum spicatum was exposed to cell extracts from microcystin(MC)-and non-MC-producing Microcystis strains in a laboratory experiment.Results showed that both Mcracystis cell extracts exerted obvious damages to plant biomass,photosynthesis,primary and secondary metabolism measures,and resistance of plant antioxidant systems,with MC-producing Microcystis having stronger effects due to the presence of MCs.Cyanotoxins other than MCs responsible for the negative effects from both strains needs further identification.The Shannon diversity and Chao1 indices of epiphytic and planktonic bacteria were decreased by the cell extracts from both Microcystis strains.However,epiphytic and planktonic bacterial communities responded differently to cell extracts at the genus level.The dominant genera of planktonic bacteria including Enterobacter,Pseudomonas,and Novosphingobium from phylum Proteobacteria,Chryseobacterium from phylum Bacteroidetes,and Microbacterium from Actinobacteriota in the treatments with cell extracts were previously reported to have strains with algicidal and MC-degrading capabilities.B acterial genes associated with energy production and conversion,amino acid transport and metabolism,and inorganic ion transport and metabolism,were more abundant in both treatments than the control for planktonic bacteria,but less abundant for epiphytic bacteria.We speculate that planktonic bacterial communities have the potential to use and degrade substances derived from Microcystis cell extracts,which may be beneficial for M.spicatum to alleviate damages from Microcystis.Further research is needed to verify the structure and function dynamics of epiphytic and planktonic bacteria in the interaction between cyanobacteria and submerged macrophytes.

关键词： microcystins Microcystis Myriophyllum spicatum dissolved organic carbon epiphytic and planktonic bacteria

H_(4)SiW_(12)O_(40)-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides: An efficient synthesis of 3,4-disubstituted 1H-pyrazoles

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Chinese Chemical Letters 2022年第3期33卷 1483-1487页

作者： Guoping Yang Xuanjie Xie Mengyuan Cheng Xiaofei GAO Xiaoling Lin Ke Li Yuanyuan Cheng Yufeng Liu Jiangxi Key Laboratory for Mass Spectrometry and Instrumentation Jiangxi Province Key Laboratory of Synthetic ChemistryEast China University of TechnologyNanchang 330013China Henan Key Laboratory of Polyoxometalate Chemistry College of Chemistry and Chemical EngineeringHenan UniversityKaifeng 475004China

A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid (H_(4)SiW_(12)O_(40))-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides/aldehydes were smoothly reacted with sulfonyl hydrazides to furnish regioselectivity 3,4-disubstituted 1H-pyrazoles. The application of such an earth-abundant, readily accessible, and nontoxic catalyst provides a green approach for the construction of 3,4-disubstituted 1H-pyrazoles. A plausible reaction mechanism has been proposed on the basis of control experiments, GC-MS and DFT calculations.

关键词： Silicotungstic acid Epoxides Aldehydes Sulfonyl hydrazides 3,4-Disubstituted 1H-pyrazoles

Rapid and sensitive method for determining free amino acids in plant tissue by high-performance liquid chromatography with fluorescence detection

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Acta Geochimica 2017年第4期36卷 680-696页

作者： Nengjian Zheng Huayun Xiao Zhongyi Zhang Xiaofei GAO Jingjing Zhao State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China University of Chinese Academy of Sciences Beijing 100049China Aquatic Ecohealth Group Key Laboratory of Urban Environment and HealthInstitute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

This paper describes a reliable and rapid method for the complete separation and quantitation of twenty-five amino acids typically found in plants, based on reversed phase high-performance liquid chromatography–linked fluorescence detector using a 150×4.6 mm Zorbax Eclipse AAA column. Plant tissue free amino acids(FAA)were extracted by ultrasonication with 5%(v/v) aqueous trifluoroacetic acid followed by ultrafiltration of extracts.The following analysis of amino acids was performed through programmed precolumn derivatization with orthophthalaldehyde and 9-fluorenylmethyl chloroformate reagents and efficient elution of derivatives within 26 min using binary gradient scheme. The method was validated over a concentration range of 4.5–450 μmol L^(-1)(μM).Separation analysis showed good selectivity(resolution>1.5) for most amino acids. The average repeatability(RSD%, relative standard deviation) of the analysis at seven calibration concentrations was below 4% and ranged from 1.13% to 12.04%. The intra-day mean coefficient of variation at two concentrations(22.5 and 90 μM) was within 2%, and the intermediate precision was less than 4%. The limits of detection were between 0.012 and 6.68 μM. The coefficients of determination(R2) of the linear calibration curves were from 0.9989 to 0.9999.When the method was applied to plant samples, the FAA recoveries at two spiked levels(25 and 100 μM) ranged from 67.0% to 108.9% with an average of 94.4%, and the precision was 0.26%–12.31% RSD. A specific application combining this method with optimized extraction and interference removal procedures was successfully used to determine the FAA pools in different plant tissues. Finally,a PLS-DA multivariate statistics model was validated for the classification of three plant species according to their FAA profiles.

关键词： HPLC OPA FMOC Free amino acids Plant PLS-DA

Comparative Study of Chinese and Japanese Language Promotion Policy

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Comparative Study of Chinese and Japanese Language Promotion...

Preparation and properties of a silver particle-coated and 1-dodecanethiol-modified superhydrophobic melamine sponge for oil/water separation

作者： Xiaofei GAO School of Foreign Languages Dalian Neusoft University of Information

It is the prerequisite for the realization of the Chinese dream of the Chinese nation’s rejuvenation to enhance the international influence of Chinese. Through the comparative analysis of the promotion policies, institutions, testing models, teachers and teaching materials of China and Japan, this paper aims to find out the experience that can be used for Chinese promotion.

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Frontiers of Chemical Science and Engineering 2022年第8期16卷 1237-1246页

作者： xiaofei Sun Shijie Feng Zhe Zhang Pengyu Zhang Jiefeng Zhao Yunling gao Junxian Yun State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology College of Chemical EngineeringZhejiang University of TechnologyHangzhou 310032China

A Ag particle-coated and 1-dodecanethiolmodified melamine sponge(Ag-DDT-MS)was prepared through surface roughness by coating silver particles and subsequent grafting of a hydrophobic long hydrocarbon chain.Superhydrophobic and 3D porous Ag-DDT-MS was characterized by Fourier transform infrared spectroscopy,scanning electron microscope,energy-dispersive X-ray spectroscopy,and X-ray diffraction.The water contact angle of Ag-DDT-MS reached 159.2°.Ag-DDT-MS exhibited excellent absorption capacity for high viscous oils and organic solvents,ranging from 42.8 to 105.2 g∙g−1.The absorbed oils can be easily collected by the mechanical pressing process,and the oil recovery rate was satisfactory,more than 90%after 20 recycles.Ag-DDT-MS material also demonstrated good stability and excellent compressionrecovery ability,keeping 88.6%of the initial height after ten compression-release cycles.

关键词： melamine sponge oil-absorbing material,hydrophobic oil-water separation oil absorption capacity

Analytical solutions for characteristic radii of circular roadway surrounding rock plastic zone and their application

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International Journal of Mining Science and Technology 2019年第2期29卷 263-272页

作者： xiaofei Guo Zhiqiang Zhao Xu gao Xiangye Wu Nianjie Ma Faculty of Resource and Safety Engineering China University of Mining and Technology (Beijing) Department of Energy and Mineral Engineering The Pennsylvania State University University Park Institute of Mining Engineering Inner Mongolia University of Science and Technology

In the non-uniform stress field, the surrounding rock plastic zone of the circular roadway shows different shapes under the different confining pressure conditions. Based on the boundary shape characteristics of the plastic zone, the characteristic radii of the plastic zone were proposed, namely the horizontal,longitudinal and medial axis radii, which could reflect the plastic zone shapes characteristics and classify the sizes of the key parts. On the theoretical basis of elastic-plastic mechanics, analytical solutions for the characteristic radii were obtained by theoretical deduction, and the relationships between the characteristic radii and key influencing factors were analyzed. Finally, the evaluation criterion of the circular roadway surrounding rock plastic zone shapes, evaluation criterion of the location of potential hazards caused by the roadway surrounding rock and evaluation critical points of roadway dynamic disasters based on characteristic radii were proposed. This work could provide a theoretical basis for stability analysis of the surrounding rock, support design, and guide the prevention and control of dynamic roadway disasters.

关键词： Inhomogeneous stress field Analytical solutions Characteristic radii Morphological identification Disaster area

Electrospun Scaff old of Collagen and Polycaprolactone Containing ZnO Quantum Dots for Skin Wound Regeneration

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Journal of Bionic Engineering 2021年第6期18卷 1378-1390页

作者： Pengfei Li Liming Ruan Ruofan Wang Tianqi Liu gao Song Xiaofei GAO Guohua Jiang Xiaoyan Liu School of Materials Science and Engineering Zhejiang SciTech UniversityHangzhou310018China Department of Dermatology Beilun People’s Hospital of Ningbo CityNingbo315800China Zhejiang-Mauritius Joint Research Center for Biomaterials and Tissue Engineering Zhejiang Sci-Tech UniversityHangzhou310018China Institute of Smart Biomedical Materials Zhejiang Sci-Tech UniversityHangzhou310018China Department of Dermatology The 1st Affi liated Hospital of Zhejiang UniversityHangzhou310003China

Nanofibers(NFs)have been widely used in tissue engineering such as wound healing.In this work,the antibacterial ZnO quantum dots(ZnO QDs)have been incorporated into the biocompatible poly(ε-caprolactone)/collagen(PCL/Col)fibrous scaffolds for wound healing.The as-fabricated PCL-Col/ZnO fibrous scaffolds exhibited good swelling,antibacterial activity,and biodegradation behaviors,which were beneficial for the applications as a wound dressing.Moreover,the PCL-Col/ZnO fibrous scaffolds showed excellent cytocompatibility for promoting cell proliferation.The resultant PCL-Col/ZnO fibrous scaffolds containing vascular endothelial growth factor(VEGF)also exhibited promoted wound-healing effect through promoting expression of transforming growth factor-β(TGF-β)and the vascular factor(CD31)in tissues in the early stages of wound healing.This new electrospun fibrous scaffolds with wound-healing promotion and antibacterial property should be convenient for treating wound healing.

关键词： Wound dressing Issue engineering scaffold Wound healing Electrospun nanofibers