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Degradation leads to dramatic decrease in topsoil but not subsoil root biomass in an alpine meadow on the Tibetan Plateau, China

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Journal of Arid Land 2020年第5期12卷 806-818页

作者： ZHANG Zhenchao liu miao SUN Jian WEI Tianxing Synthesis Research Centre of Chinese Ecosystem Research Network Key Laboratory of Ecosystem Network Observation and ModellingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYangling 712100China Arid Land Research Center Tottori UniversityTottori 6800001Japan School of Soil and Water Conservation Beijing Forestry UniversityBeijing 100083China

Understanding the effects of degradation on belowground biomass(BGB)is essential for assessment of carbon budget of the alpine meadow ecosystem on the Tibetan Plateau,*** ecosystem has been undergoing serious degradation owing to climate change and anthropogenic *** study examined the response of the vertical distribution of plant BGB to degradation and explored the underlying mechanisms in an alpine meadow on the Tibetan Plateau.A field survey was conducted in an alpine meadow with seven sequential degrees of degradation in the Zoige Plateau on the Tibetan Plateau during the peak growing season of *** measured aboveground biomass(AGB),BGB,soil water content(SWC),soil bulk density(SBD),soil compaction(SCOM),soil organic carbon(SOC),soil total nitrogen(STN),soil total phosphorus(STP),soil available nitrogen(SAN),and soil available phosphorus(STP)in the 0-30 cm soil *** results show that degradation dramatically decreased the BGB in the 0-10 cm soil layer(BGB0-10)but slightly increased the subsoil *** main reason may be that the physical-chemical properties of surface soil were more sensitive to degradation than those of subsoil,as indicated by the remarked positive associations of the trade-off value of BGB0-10 with SWC,SCOM,SOC,STN,SAN,and STP,as well as the negative correlation between the trade-off value of BGB0-10 and SBD in the soil layer of 0-10 *** addition,an increase in the proportion of forbs with increasing degradation degree directly affected the BGB vertical *** findings suggest that the decrease in the trade-off value of BGB0-10 in response to degradation might be an adaptive strategy for the degradation-induced drought and infertile soil *** study can provide theoretical support for assessing the effects of degradation on the carbon budget and sustainable development in the alpine meadow ecosystem on the Tibetan Plateau as well as other similar ecosystems in the world.

关键词： belowground biomass soil properties plant community structure degradation alpine meadow Tibetan Plateau

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Effect of Metal Cations on Corrosion Behavior and Surface Structure of Carbon Steel in Chloride Ion Atmosphere

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Acta Metallurgica Sinica(English Letters) 2020年第9期33卷 1302-1310页

作者： Yu-Wei liu Jian Zhang Xiao Lu miao-Ran liu Zhen-Yao Wang Environmental Corrosion Center Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Analysis and Testing Center Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049.China

In order to better understand why the corrosion behavior of carbon steel exposed in Nansha atmospheric environment is very serious, the effect of sodium, potassium and magnesium chlorides deposited on carbon steel surface has been studied under atmosphere conditions by wet/dry accelerated test. The difference of corrosion behavior and surface structure in Na+, K+, and Mg2+ containing atmosphere has been investigated by thickness loss, scanning electron microscope, X-ray diffraction and electrochemical techniques. The results indicate that the thickness loss of carbon steel exposed in different metal cations containing atmospheric environment increases in the order of Na+, K+, Mg2+. The hard metal cation can promote the dissolution of the steel to a certain extent. In Mg2+ containing atmosphere, the relative content of β-FeOOH is rather higher and the protective ability index α */γ * decreases in the order of Na+, K+, Mg2+. The corrosion current density of both bare carbon steel and the rusted carbon steel increases in the order of Na+, K+, Mg2+. The polarization resistance and the charge transfer resistance decreases in the order of Na+, K+, Mg2+.

关键词： Metal cation Carbon steel Chloride Atmospheric corrosion

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Vegetation Traits and Soil Properties in Response to Utilization Patterns of Grassland in Hulun Buir City, Inner Mongolia, China

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Chinese Geographical Science 2014年第4期24卷 471-478页

作者： liu miao liu Guohua WU Xing WANG Hao CHEN Li State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of Sciences University of Chinese Academy of Sciences Monitoring Station for Eco-Environment of Hulun Buir

Numerous studies have focused on vegetation traits and soil properties in grassland, few of which concerned about effects of human utilization patterns on grassland yet. Thus, this study hypothesized that human disturbance(e.g., grazing, mowing and fencing) triggered significant variation of biomass partitioning and carbon reallocation. Besides, there existed some differences of species diversity and soil fertility. To address these hypotheses of grassland with diverse utilization patterns in Hulun Buir City, Inner Mongolia, China, we sampled in situ about aboveground biomass(AGB) and belowground biomass(BGB) to evaluate their biomass allocation. Species diversity and soil properties were also investigated. Subsequently, we discussed the relationship of species diversity with environmental conditions, using data collected from 23 sites during the ecological project period of Returning Grazing Lands to Grasslands(RGLG) program. The results were as follows: 1) both AGB and BGB were lower on grazing regime than those on fencing and mowing, but the ratio of root-to-shoot(R/S) was higher on grazing regime than the other two utilization patterns; 2) neither of evenness and Simpson Index was different significantly among all grassland utilization patterns in desert, typical, and meadow grassland at 0.05. In meadow grassland, species richness of fencing pattern was significantly higher than that of grazing pattern(p < 0.05); 3) both of soil organic carbon content and soil available phosphorous content were increased significantly on fencing pattern than grazing pattern(p < 0.05) in desert grassland, and mowing patterns increased the soil nutrients(soil organic carbon, soil total phosphorous, soil available phosphorous, and soil total nitrogen) significantly compared with grazing patterns(p < 0.05) in typical grassland. However, there were no significant differences among utilization patterns in meadow grassland. In conclusion, both of AGB and BGB were increased significantl

关键词： grassland utilization pattems biomass allocation species diversity soil properties temperate grassland Hulun Buir City

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Review on effect of applied internal cooling source and vibration on metal solidification process

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Journal of Iron and Steel Research International 2023年第6期30卷 1059-1072页

作者： Yu-chao Yao miao liu Zhong-qiu liu Bao-kuan Li Yong Gan Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina China Iron&Steel Research Institute Group Co. Ltd.Beijing 100081China

Advancements in metallurgical technology have led to the emergence of high-performance requirements for metal materials,like high uniformity,high purity,and superfine *** has resulted in the development and application of internal cooling source(ICS),vibrational,and vibrational internal cooling source methods in metal solidification processes to afford products with refined crystal grains and large proportions of equiaxed *** methods have gradually been introduced into laboratories and some steel mills over the past few ***,there are few successful industrial applications of these methods,as there is no comprehensive understanding of their control theories and ***,the development,basic principles,and classifications of the three types of methods are summarized,and their impact on the solidification of molten metals and the morphology of solid products is *** addition,experimental and numerical simulation-based researches on each type of method are reviewed and their prospects for applications are briefly discussed to control metal ***,detailed future perspectives are provided on vibratory strip feeding,ICS,and pulsed magneto-oscillation ***,it will serve as a reference for future studies of the application of these and related methods in metal solidification processes.

关键词： Internal cooling source Vibration Solidification Strip feeding Grain refinement

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Response to Midgley:the costs of reproduction cannot differ between the sexes

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Journal of Plant Ecology 2022年第6期15卷 1312-1315页

作者： miao liu Helena Korpelainen Chunyang Li Department of Ecology College of Life and Environmental SciencesHangzhou Normal UniversityHangzhou 311121China Department of Agricultural Sciences Viikki Plant Science CentreUniversity of HelsinkiHelsinkiFinland Department of Tea Sciences College of Agriculture and BiotechnologyZhejiang UniversityHangzhou 310058China

Many studies have compared the reproductive cost and vegetative growth at a particular time *** our review(liu et al.2021b),we summarized those results but did not compare absolute reproductive costs between the sexes(Hultine et al.2016;Juvany and Munné-Bosch 2016).Moreover,we did not propose that the observed vegetative and environmental differences between the sexes were the only reasons for differences in sexual functioning,especially in the spreading and receiving of pollen(Midgley 2022).

关键词： reproductive summarized Response

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Doping induced morphology,crystal structure,and upconversion luminescence evolution:from Na_(3)ScF_(6):Yb/Er/Y to NaYF_(4):Yb/Er/Sc nanocrystals

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Rare Metals 2023年第3期42卷 1018-1027页

作者： miao-miao liu Guang-Chao Zheng Yang Wei Dan Tian Qing-Bo Zheng Ling Huang Juan Xie School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China Key Laboratory of Flexible Electronics(KLOFE)and Institute of Advanced Materials(IAM) Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)Nanjing Tech University(NanjingTech)Nanjing 211816China College of Materials Science and Engineering Nanjing Forestry UniversityNanjing 210037China

Impurity doping not only provides a fundamental approach to impart unique electronic,magnetic and optical properties to target nanomaterials,but also has critical influence on nucleation and growth of many functional *** the current study,Y^(3+)and Sc^(3+)were adopted to tune the shape,size,and upconversion luminescence properties of Na_(3)ScF_(6):Yb/Er and NaYF_(4):Yb/Er samples,*** Y^(3+)doping concentration was lower than 10 mol%,the size and shape of Na_(3)ScF_(6):Yb/Er(18/2)nanoparticles gradually changed from~18 nm rhombus to 36 nm ***,the coexistence of Na_(3)ScF_(6):Yb/Er and NaYF_(4):Yb/Er nanoparticles was observed during 20 mol%-50 mol%Y^(3+)doping,and finally NaYF_(4):Yb/Er nanoparticles became the only product at>60 mol%Y^(3+)doping where the role of Sc^(3+)turned into dopant and the size of nanocrystals decreased from~30 to 20 nm *** Y^(3+)and Sc^(3+)ions doping could enhance the upconversion luminescence intensity of Na_(3)ScF_(6):Yb/Er and NaYF_(4):Yb/Er samples,for which possible mechanism was proposed from the perspective of crystal ***,the upconversion luminescence details were disclosed.

关键词： Doping Crystal growth Controlled synthesis Upconversion

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A Comparative Toxicity Study of TiO2 Nanoparticles in Suspension and Adherent Culture Under the Dark Condition

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Chemical Research in Chinese Universities 2018年第1期34卷 44-50页

作者： CHEN Like liu miao LENG Su LI Zhuan College of Environment and Resources Jilin University Changchun 130012 P. R. China College of Resources and Environment Jilin Agricultural University Changchun 130118 P. R. China

The present study focused on the different acute toxicity of TiO2 nanoparticles（TiO2 NPs） towards the bacteria in suspension culture and adherent culture under the dark conditions. The study investigated the bacteria toxicity with TiO2 NPs at different concentrations（1-2000 mg/L）, sizes（10 nm, 35 nm） and specific surface areas in unit volume solution（0-224 m^2/L） characterized by the cell viability, extracellular polymeric substances（EPS） release and biofilm formation. The bacteria in adherent culture was found to be more resistant against the toxicity of TiO2 NPs compared to that in suspension culture. An NP dose and surface area dependent（rather than the size） bacterial viability was observed in suspension culture, specifically the surface area positively correlated with the toxicity of TiO2 NPs. The size of TiO2 NPs, however, played a more critical role in toxicity of TiO2 NPs in adherent culture. Therefore, the surface area dependent toxicity of TiO2 NPs is a comprehensive parameter describing the dose and size dependent toxicity of TiO2 NPs. The electron microscopic（SEM, TEM, EDX） observations suggested the EPS release and biofilm formation, during aggregation of TiO2 NPs on the bacteria after 12 h cultivation in adherent culture under the dark condition. A possible toxic mechanism could be that ＂effective surface areas＂ that directly contact with the bacterial membrane greatly contributed to the toxicity of TiO2 NPs in both suspension culture and adherent culture. Therefore, as for the possible resistance mechanism, EPS secretion and subsequent biofilm formation may protect the bacteria against the toxicity of TiO2 NPs.

关键词： Toxicity of TiO2 nanoparticle Suspension culture Adherent culture Toxic mechanism

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Preparation of new technetium-99m NNS/X complexes and selection for brain imaging agent

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Science China Chemistry 2004年第6期47卷 499-506页

作者： HE Qiange CHEN Xiangji miao Yubin liu Boli Chemistry Department Beijing Normal University Beijing 100875 China Chemistry Department Beijing Normal University Beijing 100875 China Chemistry Department Beijing Normal University Beijing 100875 China

Based on excellent experiment results of 99mTcO-MPBDA-CI, two new ligands MPTDA and MPDAA are synthesized. Then series of 99mTcO3+ complexes are prepared through adding different halide anions, followed by tests of physical chemistry qualities and biodistribution experiments. And results of these experiments show that complexes formed with MPTDA and MPDAA have better lipophilicity than those formed with MPBDA, still maintain the good brain retention ability of this type of compounds, but radioactivity uptake in blood is higher than that of 99mTcO-MPBDA and ratios of brain/blood are reduced. Obvious affections are fetched out on brain uptake and retention if fluoride, bromide or iodide anions are added. Results of experiments can be explained in reason with theoretic computation. It is confirmed that 99mTcO-MPBDA-CI has potential to develop a new type of brain imaging agent considering integrated factors such as brain uptake, retention and toxicity.

关键词： 99mTc, brain perfusion imaging agent, MPBDA, MPTDA, MPDAA.

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Collective Magnetic Behavior of Graphene Nanohole Superlattices

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Nano Research 2008年第1期1卷 56-62页

作者： Decai Yu Elizabeth MLupton miao liu Wei liu Feng liu Department of Materials Science and Engineering University of UtahSalt Lake CityUT 84112USA

We predict a new class of 2-D crystalline“bulk”magnets-the graphene nanohole(GNH)superlattices with each GNH acting like a“super”magnetic atom,using first principles *** show that such superlattices can exhibit long-range magnetic order above room temperature,with a collective magnetic behavior governed by inter-NH spin spin interactions in additional to intra-NH spin ***,magnetic semiconductors can be made by doping magnetic NHs into semiconducting NH *** possibility of engineering magnetic GNHs for storage media and spintronics applications is discussed.

关键词： Graphene magnetism spin magnetic semiconductor superlattice

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Synergistic Effect of NaCl and SO2 on the Initial Atmospheric Corrosion of Zinc Under Wet–Dry Cyclic Conditions

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Acta Metallurgica Sinica(English Letters) 2019年第6期32卷 780-796页

作者： Qi Yin Zhen-Yao Wang miao-Ran liu Chen Pan Environmental Corrosion Center Institute of Metal Research.Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China

The synergistic eff ect of NaCl and SO2 on the atmospheric corrosion of zinc has been studied at equivalent total but different ratios of molar deposition rate under wet–dry cyclic *** results show that the corrosion rates,corrosion morphologies and the composition of the corrosion products are strongly infl uenced by the molar deposition rate ratio of NaCl and SO2(NaCl/SO2).The corrosivity of NaCl and SO2 toward zinc increases in order of SO2<1:3<3:1

关键词： Atmospheric corrosion Zinc Synergistic effect Corrosivity Corrosion morphology Gordaite

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