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Distribution and mapping of temperate savanna in the sandy lands of eastern China

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Science China Earth Sciences 2025年第1期68卷 128-141页

作者： Xiaoya LI Feng WANG Tao DUAN Kaijie YANG Bin YANG Chunmei WANG Xin TIAN Qi LU institute of Ecological Conservation and Restoration Institute of Desertification Studies Chinese Academy of Forestry institute of Desertification Institute of Desertification Studies Chinese Academy of Forestry institute of Great Green Wall Satellite Application Centre for Ecology and environment MEE institute of Microelectronics Chinese Academy of Sciences Aerospace Information Research institute Chinese Academy of Sciences institute of Forest Resource Information Techniques Chinese Academy of Forestry

Savannas are distributed globally across various *** perform a significant socioeconomic role in regulating net primary productivity and the terrestrial carbon *** to the high spatial heterogeneity induced by the mixed distribution of trees and grasses,current global land-cover classification maps often classify savannas as forests or grasslands Temperate savannas in China cover a vast area,yet their spatial patterns and extent remain poorly *** study developed a novel remote sensing temperate savannas mapping method by integrating very high-resolution （VHR） unmanned aerial vehicle （UAV） and GF-6 satellite imagery based on the vegetation structure characteristics of temperate savannas using the FAO definition of *** and validation datasets were collected from VHR UAV imagery covering the main temperate savannah types with a ground area of 1818 *** fractional woody vegetation cover （FWVC） and fractional herbaceous vegetation cover （FHVC） in temperate savannas were estimated by integrating Classification and Regression Tree and Random Forest *** current distribution of temperate savannas in the Horqin and Otindag Sandy Lands of Eastern China was mapped to a unit area of 0.5 *** root-mean-square error （RMSE） values for the FWVC and FHVC models were 10.69% and 11.67%,and the R2values were 0.66 and 0.63,*** assessment indicated that the new temperate savanna map had high identification accuracy,with a Kappa coefficient of 0.70,overall accuracy of 0.88,and average accuracy of *** savannas in the sandy lands of eastern China were primarily distributed in the northern Horqin Sandy Land the central and eastern regions of the Otindag Sandy Land,and the transition zone from the southern slopes of the Greater Khingan Mountains to the plains,covering a total area of 3.27×10～6 *** main savannah types were elm,oak/maple,and shrub *** savannas were widely distributed in the Otindag Sandy

关键词： Temperate savanna UAV imagery GF-6 Fractional woody vegetation cover Fractional herbaceous vegetation cover Machine learning

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Turbulent Agglomeration of Microparticles in a Cylinder Wake Flow Using LES-DEM:Focusing on the Effect of the Reynolds Number

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Journal of Thermal Science 2025年第1期34卷 34-49页

作者： WANG Shuang MU Lin LI Xue XIE Jun DONG Ming School of Energy and Power Engineering Dalian University of Technology School of Optical Information and Energy Engineering Wuhan Institute of Technology School of Energy and environment Shenyang Aerospace University

Turbulent agglomeration is viewed as a promising technology for enhancing fine particle removal *** better understand particle transport,agglomeration behaviors,and fluid-particle interactions,we numerically explored these phenomena under cylindrical vortex wake influence using a coupled large eddy simulation and discrete element method（LES-DEM） *** validity of the LES approach was verified by comparison with available direct numerical simulation（DNS） *** adopted the Johnson-Kendall-Roberts（JKR） contact model for particle-particle *** particle dispersion and agglomeration characteristics of particles with different diameters（dp=2-20 μm） in the laminar and transition of shear layer（TrSL） flow regimes were *** particles were concentrated at the vortex centers,while larger particles accumulated around the *** agglomeration efficiency exhibited an M-shaped profile spanwise（y-direction）.With increasing Reynolds number,the agglomeration efficiency and turbulence intensity *** particle agglomeration efficiency peaks at a certain Reynolds ***,at higher Reynolds numbers,reducing the residence time of particles in the flow field decreases the agglomeration efficiency.

关键词： discrete element method large eddy simulation microparticle particle agglomeration

Effects of water level variations on the water quality of Huayang Lakes, China

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Journal of Geographical Sciences 2025年第1期35卷 173-188页

作者： AN Lesheng LIU Chun FAN Zhongya LIAO Kaihua WANG Wencai WANG Nan School of Resources and environment Anqing Normal University South China institute of environmental Sciences Ministry of Ecology and Environment The Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography and LimnologyCAS

To explore water level variations and their dynamic influence on the water quality of Huayang Lakes, the water level from 1967 to 2023 and water quality from 2015 to 2023 were analyzed using the Mann–Kendall trend test, box plots, and violin plots. The results show a notable hydrological rhythm of water level alternation between dry and flood seasons in Huayang Lakes, with an average water level of 12.82 m and a monthly range of 11.21–17.24m. Since 2017, the water level of Huayang Rivers has shown a decreasing trend of –0.02 m/*** phosphorus(TP) has become the primary pollutant. The TP concentrations in Longgan Lake(the largest lake) during the dry, rising, flood, and retreating seasons from 2015 to 2023were 0.083, 0.061, 0.050, and 0.059 mg/L, respectively. The effect of water level on TP was mainly observed during the low-water period. When the water level in the dry season rose to 12.25 and 13.00 m, the percentage of TP exceeding 0.1 mg/L in Longgan Lake decreased to 55.8% and 33.3%, respectively. During the dry season, wind and wave disturbances caused the release of endogenous phosphorus in Huayang Lakes. This led to drastic fluctuations in TP concentration, reducing the correlation between water level and TP. When external control is limited, the water level during the dry season should be maintained between 12.25 and 13.0 m. Additionally, it is necessary to accelerate the restoration of submerged macrophyte species(such as Hydrilla verticillata and Vallisneria natans) in the Huayang Rivers.

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Efficient photocatalytic reduction of CO2 to formate by a molecular noble metal-free system

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Science China Chemistry 2025年第1期68卷 152-156页

作者： Lihua Zhang Lingjing Chen Huatian Shi Yue Wei Gui Chen Tai-Chu Lau School of environment and Civil Engineering Research Center for Eco-environmental Engineering Dongguan University of Technology Department of Chemistry and institute of Molecular Functional Materials City University of Hong Kong

Reducing CO2to carbon-neutral solar fuels can not only alleviate the energy demand but also mitigate the greenhouse *** present,developing an efficient non-noble metal photo/electrocatalytic system for converting CO2to a specific product beyond CO is still a big ***,we report a new cobalt complex bearing 2,2′-bi-1,10-phenanthroline ligand that can photocatalytically reduce CO2to formate （HCOO-）.Turnover number （TON） for HCOO-up to 677 with 99%selectivity can be achieved using organic dyes purpurin as photosensitizer and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole （BIH） as sacrificial reductant in a CO2-saturated NMP/TEA （v/v,3:1） solution under visible light *** potential electrolysis at-1.41 V （***/Ag Cl） in the presence of 12 m M Et3NHBF4also produced HCOO-with Faradaic efficiency of 39%.Spectroscopic and electrochemical studies suggest that a[CoI-H]species is the key intermediate for CO2reduction.

关键词： photocatalysis noble metal-free CO2 reduction formate cobalt hydride

Constructing 2D bismuth-based heterostructure for highly efficient photocatalytic CO2 reduction

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Tungsten 2025年第1期7卷 71-79页

作者： Ruo-Hang Xu Hao-Yu Jiang Dan-Dan Cui Kun-Rong Du Hong-Run Zhang Sheng-Jie Xu Ya-Qi Li Zhi-Zhen Ren Liang Wang Wei-Chang Hao Yi Du School of Physics and BUAA-UOW Joint Research Centre Beihang University Shenzhen institute of Beihang University Centre for Catalysis and Clean Energy School of Environment and Science Griffith University

Reforming carbon dioxide（CO2） into fuels and valuable chemicals using solar energy holds significant potential for emission reduction and addressing energy supply *** recombination of photocarriers remains a major obstacle,however,to enhancing solar energy conversion efficiency in the photocatalytic reaction *** two-dimensional materials,constructing heterogeneous structures has emerged as an effective strategy to enhance the separation of photoexcited carriers by leveraging the internal electric field at the heterogeneous ***,we present a facile strategy for preparing Bi4NbO8Br/Bi2WO6plate-on-plate Z-scheme junctions with a strong internal electric field by in situ *** unique heterostructure facilitates efficient separation and transport of photoexcited charges by harnessing the internal electric field induced by chemical bonding at the lateral ***,the Bi4NbO8Br/Bi2WO6heterostructure exhibits enhanced CO2photoreduction properties,along with a CO yield rate of approximately 35 μmol·g-1·h-1under full light *** work offers novel insights into the synthesis of unique hetero structures intended to enhance the efficiency of photocatalytic CO2reduction.

关键词： Bi4NbO8Br/Bi2WO6 CO2 reduction Heterostructures Photocatalysts

Transient receptor potential channels and calcium dysregulation: a pathogenic duo in Parkinson's disease

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Neural Regeneration Research 2025年第3期20卷 808-810页

作者： Iqira Saeed Linlin Ma Griffith institute for Drug Discovery Griffith UniversityNathanBrisbaneQLDAustralia School of environment and Science Griffith University NathanBrisbaneQLDAustralia

Parkinson's disease(PD) has a complex and multifactorial pathophysiology. Various studies, conducted both in pre-clinical models and PD patients, have reported a link between the disruption of calcium(Ca^(2+)) homeostasis and the subsequent development of PD. Ca^(2+) regulation is crucial for neuronal survival, differentiation,exocytosis at synapses,gene transcription,and proliferation.

关键词： homeostasis clinical subsequent

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Propagating subduction initiation of the Caroline Plate at the Mussau Trench

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Science China Earth Sciences 2025年第1期68卷 253-269页

作者： Chun-Feng LI Yongkang DENG Tao WU Dongdong DONG Guoliang ZHANG Jiazheng ZHANG Yutao LIU Yaqing LI Fugui TANG Lulu ZHANG Department of Marine Sciences Zhejiang University Laboratory of Marine Mineral Resources Laoshan Laboratory Key Lab of Marine Geology and environment Institute of Oceanology Chinese Academy of Sciences Key Lab of Ocean and Marginal Sea Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Science & Technology on Integrated Information System Lab Institute of Software Chinese Academy of Sciences

New seismic imaging from the Mussau Trench confirms that, under horizontal compression on an oceanic plate boundary, it is within the young and weak oceanic plate that a trench will develop, and it is the young plate, not so long after its birth, that starts to subduct toward the old plate. The Mesozoic Pacific Plate cannot easily bend, under the joint horizontal compression and vertical gravity pull, even with a pre-existing weak zone in place and with a large age offset across the plate boundary. The bending of the Caroline Plate near the northern end of the Mussau Trench started only after a long-time span of trench migration, and/or after a prolonged transition from initial compression to trench development. Highly contrasting trench deformation and sedimentary accretion between two parallel seismic sections support an evident migration of underthrusting or significant longitudinal heterogeneity along the trench. The swift transition from underthrusting to non-thrusting can be explained by a counter-clockwise rotation of the Caroline Plate. That miniature accretionary wedges develop even before the subduction initiates imply strong compression and uplifting before the underthrusting can kick-start. Rotation of the Caroline Plate have been halted as the Mussau Trench is seismically rather quiet and the Lyra Trough to the east shows relaxational extension.

关键词： Mussau Trench Subduction initiation Seismic reflection Caroline Plate

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Marine dispersion of Fukushima-derived radiocesium in the North Pacific and its implications

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Science China Earth Sciences 2025年

作者： Tong ZHANG Xiaolin HOU Yukun FAN State Key Laboratory of Loess and Quaternary Geology Shaanxi Key Laboratory of Accelerator Mass Spectrometry Technology and Application Xi'an AMS Center Institute of Earth Environment Chinese Academy of Sciences University of Chinese Academy of Sciences Xi'an institute for Innovative Earth environment Research

A key scientific approach to addressing the environmental radiation risks from Fukushima nuclear contaminated water （FNCW） discharge into the ocean is understanding and predicting the marine dispersion of *** dispersion of radiocesium (CsF:134Cs,137Cs) from the Fukushima nuclear accident in the North Pacific and its marginal seas post-2011 was systematically summarized,focusing on pathways,vertical distribution changes,and transit *** research examined CsFdispersion through the Kuroshio Extension and denser central mode water （D-CMW） to the eastern North Pacific,as well as through subtropical mode water （STMW）,lighter central mode water （L-CMW）,and D-CMW to the subtropical western North Pacific,China Seas,and Sea of *** considered broader implications of CsFdispersion in light of ongoing FNCW *** this prolonged liquid discharge and Kuroshio Extension’s barrier effect,it is crucial to emphasize the role of CMW besides STMW in transporting FNCW to the subtropical western North Pacific and its marginal *** research should focus on the key mechanism and longitude range of CMW crossing the Kuroshio *** short-lived134Cs decays rapidly during the storage and dispersion of FNCW,long-lived135Cs and135Cs/137Cs ratios can serve as valuable tracers for detecting and quantifying ***,there is an urgent need for high-precision analysis of these key radionuclides and their characteristic *** promptly detect,assess,and respond to FNCW intrusion,continuous monitoring and identification of nuclear pollution sources in key ocean currents and straits are ***,interdisciplinary research integrating monitoring with marginal sea circulation dynamics and high-resolution numerical simulations should be a priority

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Relationship Between Developmental Intensity of Landslide and Malan Loess Cohesion at a Regional Horizontal Space Scale

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Journal of Earth Science 2025年

作者： Yongheng Zhou Yaming Tang Bo Hong Fan Feng Longhui Wang institute of Geological Survey， China University of Geosciences (Wuhan) institute of Earth environment， Chinese Academy of Sciences Xi'an Geological Survey Center China Geological Survey Chinese Academy of Geological Sciences

Malan loess is highly water-sensitive， with its shear strength， particularly cohesive strength， significantly decreasing under the influence of water. The Western Shanxi Loess Plateau （WSLP） is especially prone to loess landslides， which are closely linked to rainfall infiltration. Understanding the regional variation of Malan loess cohesion (cm) and its distribution in relation to the developmental intensity of landslides in this area can provide essential scientific evidence for effective landslide prevention. Loess landslides and Malan loess were selected as the objects of study for the current research. The regional variation and distribution pattern of the cmwere revealed through undisturbed loess direct shear tests and Inverse Distance Weighting （IDW） interpolation. The relationship between the developmental intensity of landslide and the regional variation of the cmwas explored using the Cumulative Sum Variable Dimension Fractal （CSVDF）， Frequency Ratio （FR） model， and Certainty Factor （CF） model. The following conclusions were drawn: Results from the direct shear tests and IDW method indicate that the cmtends to decrease from south to north and exhibits a positively skewed spatial distribution pattern. The CSVDF results indicates a similarity between the regional variation of the cmand the development intensity of loess landslides. The FR and CF results reveal that loess landslides are more likely to occur when the cmis between 0 and 16.14 kPa.

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