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ⅢA-ⅡB multicomponent perovskite rare earth ferrites with promising electromagnetic wave absorption properties

Journal of Rare earths 2024年第6期42卷 1118-1127,I0005页

作者： Yanyan He Tao Chen Yanyu Pan Minzhong Huang Kaixian Wang Liyan Xue Yazhu Li Fengzhi Tan Fan Yang Tongkuan Xu Heng Chen School of Light Industry and Chemical Engineering Dalian Polytechnic UniversityDalian116034China Xiamen institute of Rare earthMaterials Haixi InstitutesChinese Academy of SciencesXiamen36021China Fujian institute of Research on the Structure of Matter Chinese Academyof SciencesFuzhou350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou350108China Xiamen Key-Laboratoryof Rare earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen361021China Key Laboratory of Rare earths Ganjiang Innovation AcademyChinese Academy of SciencesGanzhou3410ooChina

Perovskite-type rare-earth ferrites(REFeO_(3))are promising materials for absorbing electromagnetic(EM)wave ***,insufficient dielectric loss and poor impedance matching are key factors that limit the broader implementation of REFeO_(3).Herein,a series of multicomponent perovskite-type ferrites with strong EM wave absorption capabilities was *** the synergistic effect of chemical constitution regulation and entropy regulation,optimization of the dielectric loss and impedance matching is achieved by strengthening the structural defect mechanism,thus further adjusting the EM wave absorption *** with(LaGdSmNdBa)FeO_(3)(HE-1)and(LaGdPrSmNdBa)FeO_(3)(HE-2),(LaGdBa)FeO_(3)(ME-1)and(LaGdSmBa)FeO_(3)(ME-2)exhibit favorable performance,with optimal minimum reflection loss(RL_(min))of-56.35 dB(at 11.12 GHz)and-63.25 dB(at 7.22 GHz)and effective absorption bandwidth(EAB)of 4.46 and 4.72 GHz,*** multicomponent design provides a new strategy for the development of EM wave absorption materials.

关键词： Rare earths Multicomponent design Rare earth ferrites Entropy regulation Electromagnetic wave absorption

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Changes in albedo and its radiative forcing of grasslands in East Asia drylands

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Ecological Processes 2024年第1期13卷 237-251页

作者： Qingsong Zhu Jiquan Chen Liangxu Wu Yuting Huang Changliang Shao Gang Dong Zhe Xu Xianglan Li State Key Laboratory of Remote Sensing Science College of Global Change and Earth System Science Faculty of Geographical ScienceBeijing Normal University Department of Geography Environment and Spatial Sciences Michigan State University State Key Laboratory of Efficient Utilization of Arid and Semi-Arid Arable Land in Northern China National Hulunber Grassland Ecosystem Observation and Research Station Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences School of life Science Shanxi University

Background Grasslands in drylands are increasingly influenced by human activities and climate change, leading to alterations in albedo and radiative energy balance among others. Surface biophysical properties and their interactions change greatly following disturbances. However, our understanding of these processes and their climatic impacts remains limited. In this study, we used multi-year observations from satellites and eddy-covariance towers to investigate the response of albedo to variables closely associated with human disturbances, including vegetation greenness（EVI） and surface soil volumetric water content（VWC）, as well as snow cover and clearness index（Ta） for their potential *** EVI and VWC during the growing season were the primary factors influencing albedo. EVI and VWC were negatively correlated with albedo, with VWC's total direct and indirect impacts being slightly smaller than those of EVI. During the non-growing season, snow cover was the most influential factor on albedo. VWC and Ta negatively affected albedo throughout the year. We estimated the impact of variations in EVI and VWC on climate to be in the range of 0.004 to 0.113 kg CO2m-2yr-1in *** This study indicates the significant impacts of climate change and human disturbances on vulnerable grassland ecosystems from the perspective of altered albedo. Changes in vegetation greenness and soil properties induced by climate change and human activities may have a substantial impact on albedo, which in turn feedback on climate change, indicating that future climate policies should take this factor into consideration.

关键词： Albedo Global warming potential Grassland Disturbance

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Revisiting the Mg isotopic systematics of siliciclastic components of sediments and sedimentary rocks:A new geochemical proxy of continental weathering in earth's history

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Science China earth Sciences 2024年第2期67卷 620-633页

作者： Tianzheng HUANG Bing SHEN Kangjun HUANG Meng NING Chao LI Jinzhuang XUE Yuanlin SUN Baoqi HUANG Key Laboratory of Orogenic Belt and Crustal Evolution MOESchool of Earth and Space SciencesPeking UniversityBeijing100871China State Key Laboratory of Continental Dynamics Shaanxi Key Laboratory of Early Life and EnvironmentsDepartment of GeologyNorthwest UniversityXi’an710069China institute of Sedimentary Geology Chengdu University of TechnologyChengdu610059China Key Laboratory of Rhenium-Osmium Isotopic Geochemistry Chinese Academy of Geological SciencesBeijing100037China

The Mg isotopic compositions of siliciclastic components(δ^(26)Mg_(sili))of sediments and sedimentary rocks have been commonly used to constrain the intensity of continental weathering,based on observations of,(1)an upward enrichment of26Mg in modern weathering profiles,(2)preferential uptake of26Mg in soil clays,and(3)general positive correlations between weathering intensities andδ^(26)Mg_(sili)***,not all weathering profiles display an upward increase ofδ^(26)Mg_(sili),and not all soil clays enrich in26Mg,complicating the interpretations ofδ^(26)Mg_(sili)data of sediments and sedimentary *** further explore the controls ofδ^(26)Mg_(sili)of sediments and sedimentary rocks,here we measuredδ^(26)Mg_(sili),mineralogical compositions and major element compositions of deep sea sediments from South China Sea(SCS)and carbonate rock samples from two late Paleozoic sections in South *** samples show decreasing trends of both normalized Mg concentration(Mgnorm)andδ^(26)Mg_(sili)values with the increase of weathering intensity,while SCS sediments samples do not show any correlation between Mgnormorδ^(26)Mg_(sili)values and weathering intensity.A three-stages weathering model is developed to explain the observed Mgnorm andδ^(26)Mg_(sili)*** the new model,weathering can be divided into three stages,(1)the preliminary weathering stage characterized by dissolution of primary minerals and formation of secondary clay minerals in saprolite,(2)the transitional stage with massive vermiculite and chlorite formation on the bottom of soil,and(3)the advanced stage showing dissolution of vermiculite and chlorite in the top of *** new model explains anδ^(26)Mg_(sili)increase and Mgnormdecrease with an increase weathering intensity in preliminary weathering stage and decrease of Mgnormandδ^(26)Mg_(sili)with increase weathering intensity in advanced weathering *** revised weathering model warrants the application of Mg isotope in the study of contin

关键词： Clay mineral Chemical weathering CIA Soil Weathering model

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All-inorganic nitrate electrolyte for high-performance lithium oxygen battery

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Nano Research 2024年第5期17卷 4163-4170页

作者： Dongyue Yang Jiayi Du Kai Chen Haoran Zhang Gang Huang Tong Liu Xinbo Zhang Hongjie Zhang State Key Laboratory of Rare earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Lithium-oxygen(Li-O_(2))batteries have been regarded as an expectant successor for next-generation energy storage systems owing to their ultra-high theoretical energy ***,the comprehensive properties of the commonly utilized organic salt electrolyte are still unsatisfactory,not to mention their expensive prices,which seriously hinders the practical production and application of Li-O_(2) ***,we have proposed a low-cost all-inorganic nitrate electrolyte(LiNO_(3)-KNO_(3)-DMSO)for Li-O_(2) *** inorganic nitrate electrolyte exhibits higher ionic conductivity and a wider electrochemical stability window than the organic salt *** existence of K+can stabilize the O_(2)-intermediate,promoting the discharge process through the solution pathway with an enlarged *** at an ultra-low concentration of 0.01 M,the K+can still remain stable to promote the solution discharge process and also possess a new function of inhibiting the dendrite growth by electrostatic shielding,further enhancing the battery stability and contributing to the long cycle *** a result,in the 0.99 M LiNO_(3)-0.01 M KNO_(3)-DMSO electrolyte,the Li-O_(2) batteries exhibit prolonged cycling performance(108 cycles)and excellent rate performance(2 A·g^(-1)),significantly superior to the organic salt one.

关键词： Li-O_(2)batteries potassium ions inorganic nitrate electrolyte solution pathway mechanism

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Prediction of soil organic carbon stock combining Sentinel-1 and Sentinel-2 images in the Zoige Plateau, the northeastern Qinghai-Tibet Plateau

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Ecological Processes 2024年第2期13卷 165-176页

作者： Junjie Lei Changli Zeng Lv Zhang Xiaogang Wang Chanhua Ma Tao Zhou Benjamin Laffitte Ke Luo Zhihan Yang Xiaolu Tang State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Sichuan Academy of Geological Survey Sichuan institute of Nuclear Geological Survey College of earth Sciences Chengdu University of Technology Tianfu Yongxing Laboratory

Background Soil organic carbon（SOC） is a critical component of the global carbon cycle, and an accurate estimate of regional SOC stock（SOCS） would significantly improve our understanding of SOC sequestration and cycles. Zoige Plateau, locating in the northeastern Qinghai-Tibet Plateau, has the largest alpine marsh wetland worldwide and exhibits a high sensitivity to climate fluctuations. Despite an increasing use of optical remote sensing in predicting regional SOCS, optical remote sensing has obvious limitations in the Zoige Plateau due to highly cloudy weather, and knowledge of on the spatial patterns of SOCS is limited. Therefore, in the current study, the spatial distributions of SOCS within 100 cm were predicted using an XGBoost model—a machine learning approach, by integrating Sentinel-1, Sentinel-2 and field observations in the Zoige *** The results showed that SOC content exhibited vertical distribution patterns within 100 cm, with the highest SOC content in topsoil. The tenfold cross-validation approach showed that XGBoost model satisfactorily predicted the spatial patterns of SOCS with a model efficiency of 0.59 and a root mean standard error of 95.2 Mg ha-1. Predicted SOCS showed a distinct spatial heterogeneity in the Zoige Plateau, with an average of 355.7 ± 123.1 Mg ha-1within 100 cm and totaled 0.27 × 10～9 Mg *** High SOC content in topsoil highlights the high risks of significant carbon loss from topsoil due to human activities in the Zoige Plateau. Combining Sentinel-1 and Sentinel-2 satisfactorily predicted SOCS using the XGBoost model, which demonstrates the importance of selecting modeling approaches and satellite images to improve efficiency in predicting SOCS distribution at a fine spatial resolution of 10 m. Furthermore, the study emphasizes the potential of radar（Sentinel-1） in developing SOCS mapping, with the newly developed fine-resolution mapping having important applications in land management, ecological resto

关键词： SOC Vegetation index Texture XGBoost Sentinel-1 Sentinel-2

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Holocene Hydroclimatic Variations in the Asian Drylands:Current Understanding and Future Perspectives

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Journal of earth Science 2024年第1期35卷 292-295页

作者： Guoqiang Ding Shengqian Chen Yuanhao Sun Shuai Ma Jianhui Chen MOE Key Laboratory of West China's Environmental System College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Alpine Paleoecology and Human Adaptation Group State Key Laboratory of Tibetan Plateau Earth SystemEnvironment and ResourcesInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

0 *** intensification of global warming is generating increasing risks to human society and sustainable development,which are of growing concern to the international scientific community and policymakers(Sun,2023).The ecosystems of the Asian drylands are fragile and highly sensitive to global changes;moreover,while these drylands are the most important areas of oasis agriculture on earth,their water resources are being adversely impacted by ongoing climate change(Zhang et al.,2023).Hence,an improved understanding of the patterns of climate change in this region is important and attracting increasing research attention.

关键词： Asian Holocene climatic

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Viscoelastic stress change from the 1931 M_(w)7.8 Fuyun earthquake and its impacts on seismic activity around the Altai mountains

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Geodesy and Geodynamics 2024年第4期15卷 326-337页

作者： Yali Shao jiankun He Xinguo Wang Youjia Zhao Key Laboratory of Tibetan Plateau earth System Environment and ResourcesInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

The 1931 M_(w)7.8 Fuyun earthquake occurred around the Altai mountains, an intracontinental deformation belt with limited active strain-rate accumulation. To explore whether seismic activity in this deformation belt was affected by stress interaction among different active faults, we calculate the Coulomb failure stress change(ΔCFS) induced by the Fuyun earthquake due to coseismic deformation of the elastic crust and postseismic viscoelastic relaxation of the lower crust and upper mantle. Numerical results show that the total ΔCFS at a 10-km depth produced by the Fuyun earthquake attains approximately 0.015-0.134 bar near the epicenter, and just before the occurrence of the 2003 M_(w)7.2 Chuya earthquake, which distances about 400 km away from the Fuyun earthquake. Among the increased ΔCFS,viscoelastic relaxation from 1931 to 2003 contributes to approximately 0.014-0.131 bar, accounting for>90% of the total ΔCFS. More importantly, we find that for the recorded seismicity in the region with a radius of about 270 km to the Fuyun earthquake from 1970 to 2018, the percentage of earthquakes that fall in positive lobes of ΔCFS resolved on the NNW-SSE Fuyun strike-slip fault, on the NWW-SEE Irtysh strike-slip fault, and on the NW-SE Kurti reverse fault is up to 67.22%-91.36%. Therefore, the predictedΔCFS suggests that the impact of the 1931 M_(w)7.8 Fuyun earthquake on seismic activity around the Altai mountains is still significant as to hasten occurrence of the 2003 M_(w)7.2 Chuya earthquake at a relatively far distance and to trigger its aftershocks in the near-field even after several decades of the mainshock.

关键词： Altai mountains Fuyunearthquake Coulomb failure stress change Viscoelasticrelaxation Seismic activity

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Sources, enrichment mechanisms, and resource effects of rare metal elements-enriched geothermal springs in Xizang, China

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Science China earth Sciences 2024年第11期67卷 3476-3499页

作者： Fei XUE Hongbing TAN Xiying ZHANG Jinbao SU School of earth Sciences and Engineering Hohai University Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes Qinghai Institute of Salt Lakes Chinese Academy of Sciences School of Oceanology Hohai University

Rare metals such as lithium(Li), rubidium(Rb), and cesium(Cs) are strategically crucial mineral resources for the development of emerging industries in China. Ensuring a stable long-term supply of these resources is essential. The geothermal systems in Xizang, China are well-developed, with a wide distribution of various types. Most high-temperature geothermal systems in Xizang are exceptionally enriched in rare metal elements(RMEs) and have the potential to become a new source of rare metals to secure China's strategic mineral resource supply in the future. A close relationship also exists between the geothermal system and the special salt lake resources on the Tibetan Plateau. Geothermal springs thus play a key role in the migration and enrichment of RMEs from deep to shallow parts of the crust, in the transition between endogenous and exogenous mineralization, and source-to-sink processes. However, the mechanisms of element enrichment and evolution in these springs have not been systematically discussed, and many theoretical issues remain to be investigated. Based on summarizing and analyzing previous research, this study employs hydrochemical and isotopic geochemistry methods to investigate typical geothermal springs across Xizang and explore the anomalous enrichment mechanism of RMEs, and the resource effects of geothermal springs. Comprehensive analysis shows that the total dissolved solids(TDS) and hydrochemical types of geothermal springs are similar to those of major geothermal fields worldwide, but the Tibetan springs are abnormally rich in Li(averaging5.48 mg/L), Rb(averaging 0.75 mg/L), and Cs(averaging 3.58 mg/L), which are hundreds to thousands of times more concentrated than natural waters. The distribution of these enriched geothermal springs is controlled by the Yarlung Zangbo suture zone and the extended N-S trending rifts, especially in the intersection zone of the two, where the geothermal springs are the most enriched. Based on the spatial distr

关键词： Geothermal springs Rare metal elements Enrichment mechanisms Salt lakes Tibetan Plateau

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Disaster effects of climate change in High Mountain Asia:State of art and scientific challenges Disaster effects of climate change in High Mountain Asia:State of art and scientific challenges

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Advances in Climate Change Research 2024年第3期15卷 367-389页

作者： Hao WANG Bin-Bin WANG Peng CUI Yao-Ming MA Yan WANG Jian-Sheng HAO Yu WANG Ya-Mei LI Li-Jun SUN Jiao WANG Guo-Tao ZHANG Wei-Mo LI Yu LEI Wen-Qing ZHAO Jin-Bo TANG Chao-Yue LI institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China State Key Laboratory of Tibetan Plateau earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China China‒Pakistan Joint Research Center on earth Sciences Chinese Academy of SciencesIslamabad 45320Pakistan College of earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China College of Atmospheric Science Lanzhou UniversityLanzhou 730000China National Observation and Research Station for Qomolongma Special Atmospheric Processes and Environmental Changes Dingri 858200China

High Mountain Asia(HMA)shows a remarkable warming tendency and divergent trend of regional precipitation with enhanced meteorological *** rapid thawing of the HMA cryosphere may alter the magnitude and frequency of nature *** reviewed the influence of climate change on various types of nature hazards in HMA region,including their phenomena,mechanisms and *** reveals that:1)the occurrences of extreme rainfall,heavy snowfall,and drifting snow hazards are escalating;accelerated ice and snow melting have advanced the onset and increased the magnitude of snowmelt floods;2)due to elevating trigger factors,such as glacier debuttressing and the rapid shift of thermal and hydrological regime of bedrock/snow/ice interface or subsurface,the mass flow hazards including bedrock landslide,snow avalanche,ice-rock avalanches or glacier detachment,and debris flow will become more severe;3)increased active-layer detachment and retrogressive thaw slumps slope failures,thaw settlement and thermokarst lake will damage many important engineering structures and infrastructure in permafrost region;4)multi-hazards cascading hazard in HMA,such as the glacial lake outburst flood(GLOF)and avalanche-induced mass flow may greatly enlarge the destructive power of the primary hazard by amplifying its volume,mobility,and impact force;and 5)enhanced slope instability and sediment supply in the highland areas could impose remote catastrophic impacts upon lowland regions,and threat hydropower security and future water *** future,ongoing thawing of HMA will profoundly weaken the multiple-phase material of bedrock,ice,water,and soil,and enhance activities of nature *** and cascading hazards of high magnitude will prevail in *** the glacier runoff overpasses the peak water,low flow or droughts in lowland areas downstream of glacierized mountain regions will became more frequent and *** escalating hazards in the HMA region requires tackling s

关键词： High Mountain Asia Climate change Cryosphere degradation Nature hazards Disaster risk

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Microstructures,Deformation Mechanisms and Seismic Properties of Synkinematic Migmatite from Southeastern Tibet:Insights from the Migmatitic Core of the Ailao Shan-Red River Shear Zone,Western Yunnan,China

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Journal of earth Science 2024年第4期35卷 1149-1169页

作者： Weiwei Ma Bo Zhang Fulong Cai Baoyou Huang Lei Zhang Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking UniversityBeijing100871China institute of Tibetan Plateau Research Chinese Academy of SciencesBeijing100085China

Seismic anisotropy originating within the continental crust is commonly used to determine the deformation and kinematic flow within active orogens and is attributed to regionally oriented mica or hornblende ***,naturally deformed rocks usually contain compositional layers(e.g.,parallel compositional banding).It is necessary to understand how both varying mineral contents and differing intensities of compositional layering influence the seismic properties of the deep *** this study,we analyzed the seismic response of migmatitic amphibolite with compositional banding *** present the microstructures,fabrics,calculated seismic velocities,and seismic anisotropies of mylonitic amphibolite from a horizontal shear layer preserved within the Ailao Shan-Red River shear zone,southwestern Yunnan,*** investigated sample is characterized by pronounced centimeter-scale compositional *** microstructures and fabrics suggest that migmatitic amphibolite rocks within deep crust may delineate regions of deformation-assisted,channelized,reactive,porous melt *** origin of compositional banding in the studied migmatitic amphibolite is attributed primarily to partial melting together with some horizontal shearing *** microfabrics and structures investigated in this study are considered to be typical for the base of active horizontal shear layers in the deep crust of southeastern *** responses are modeled by using crystal preferred orientations for minerals of the migmatitic amphibolite by applying the Voigt-Reuss-Hill homogenization *** P-wave and S-wave velocities are largely consistent in the various layers of the ***,seismic anisotropies of P-wave(AV_(p))and S-wave(AVs)are higher in the melanosomes(AV_(p)=5.6%,AV_(s)=6.83%)than those in the leucosomes and the whole rock(AV_(p)=4.2%–4.6%,AV_(s)=3.1%–3.2%).In addition,there is pronounced,S-wave splitting oblique to the foliation plane in the migm

关键词： deformation-assisted melt flow seismic anisotropy microstructure compositional banding migmatite deep crust southeastern Tibet

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