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A model for predicting marine shale gas sweet spots based on relative sea-level changes and its application 被引量:1
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作者 Hongyan Wang Zhensheng Shi +2 位作者 Xi Yang Qun Zhao Changmin Guo 《Energy Geoscience》 2025年第2期142-154,共13页
Gas-bearing shales have become a major source of future natural gas production worldwide.It has become increasingly urgent to develop a reliable prediction model and corresponding workflow for identifying shale gas sw... Gas-bearing shales have become a major source of future natural gas production worldwide.It has become increasingly urgent to develop a reliable prediction model and corresponding workflow for identifying shale gas sweet spots.The formation of gas-bearing shales is closely linked to relative sealevel changes,providing an important approach to predicting sweet spots in the Wufeng-Longmaxi shale in the southern Sichuan Basin,China.Three types of marine shale gas sweet spots are identified in the shale based on their formation stages combined with relative sea-level changes:early,middle,and late transgression types.This study develops a prediction model and workflow for identifying shale gas sweet spots by analyzing relative sea-level changes and facies sequences.Predicting shale gas sweet spots in an explored block using this model and workflow can provide a valuable guide for well design and hydraulic fracturing,significantly enhancing the efficiency of shale gas exploration and development.Notably,the new prediction model and workflow can be utilized for the rapid evaluation of the potential for shale gas development in new shale gas blocks or those with low exploratory maturity. 展开更多
关键词 Shale gas Sweet spot Relative sea-level change Wufeng-longmaxi shale Southern sichuan basin
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Monitoring absolute vertical land motions and absolute sea-level changes from GPS and tide gauges data over French Polynesia
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作者 Xianjie Li Jean-Pierre Barriot +2 位作者 Bernard Ducarme Marania Hopuare Yidong Lou 《Geodesy and Geodynamics》 EI CSCD 2024年第1期13-26,共14页
In this study,we estimate the absolute vertical land motions at three tidal stations with collocated Global Navigation Satellite System(GNSS)receivers over French Polynesia during the period 2007-2020,and obtain,as an... In this study,we estimate the absolute vertical land motions at three tidal stations with collocated Global Navigation Satellite System(GNSS)receivers over French Polynesia during the period 2007-2020,and obtain,as ancillary results,estimates of the absolute changes in sea level at the same locations.To verify our processing approach to determining vertical motion,we first modeled vertical motion at the International GNSS Service(IGS)THTI station located in the capital island of Tahiti and compared our estimate with previous independent determinations,with a good agreement.We obtained the following estimates for the vertical land motions at the tide gauges:Tubuai island,Austral Archipelago-0.92±0.17 mm/yr,Vairao village,Tahiti Iti:-0.49±0.39 mm/yr,Rikitea,Gambier Archipelago-0.43±0.17 mm/yr.The absolute variations of the sea level are:Tubuai island,Austral Archipelago 5.25±0.60 mm/yr,Vairao village,Tahiti Iti:3.62±0.52 mm/yr,Rikitea,Gambier Archipelago 1.52±0.23 mm/yr.We discuss these absolute values in light of the values obtained from altimetric measurements and other means in French Polynesia. 展开更多
关键词 GPS Tide gauges Sea level changes Vertical land motion
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Sedimentary Features and Sea-Level Changes Reflected in Drill Holes in the Zhuhai Area
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作者 CHEN Junren WAN Ling 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1999年第2期216-224,共9页
Abstract Experimental examinations and analyses have been made of the sediments from drill holes in the Zhuhai area, Guangdong Province. The studies show that there occurred four transgressions in this area over the h... Abstract Experimental examinations and analyses have been made of the sediments from drill holes in the Zhuhai area, Guangdong Province. The studies show that there occurred four transgressions in this area over the historical times. The first transgression occurred at 7500 a B.P., with the maxium sea level up to about 1 m above the present level. The second transgression occurred at 5750 a B.P., with the sea level possibly 4 m higher than the present. The third and fourth transgressions took place at 4650 a B.P. and 2600 a B.P. respectively, which lasted for a long time with multiple fluctuations. The fifth transgression is in process. It could be predicted that the sea level at Zhuhai would rise by 15–20 cm in the coming 50 years. 展开更多
关键词 sedimentary features sea-level changes Zhuhai
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Preliminary research on sea-level changes of the South China coast since late Epipleistocene
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作者 Zhang Hunan Zhao Hongmei Seismological Bureau of Guangdong Province, Guangzhou 510070, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1991年第4期565-591,共27页
Several views on sea-level changes of the South China coast are briefly introduced in this paper. On the basis of 236 samples whose ages are determined by 14C chronological method and their sites are corrected with an... Several views on sea-level changes of the South China coast are briefly introduced in this paper. On the basis of 236 samples whose ages are determined by 14C chronological method and their sites are corrected with ancient water depth and crustal deformation, a basic model about sea-level changes of the South China coast since late Epipleistocene is set up. This model basically accords with the general cognitions of predecessors, i. e. it not only represents the common characteristics of sea-level changes of the East China coast but has some features of the South China coast itself. In general, this model is relatively close to the Fairbridge's curve, indicating that the sea-level undulations exist since 6 ka ago but the ranges of undulations are slightly larger than those of Fairbridge's curve. 展开更多
关键词 than Preliminary research on sea-level changes of the South China coast since late Epipleistocene HO
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Carbon Isotope from Shallow Marine System in North China:Implications for Stratigraphical Correlation and Sea-Level Changes in Cambrian 被引量:3
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作者 Jingxun Zuo Xuejian Zhu +1 位作者 Yonglin Chen Wenjian Zhai 《Journal of Earth Science》 SCIE CAS CSCD 2023年第6期1777-1792,共16页
Cambrian System at the Shatan Section in northern Henan,North China,consists of sedimentary successions of tidal flat and shallow-water carbonate platform facies.Data of carbon isotope(δ^(13)C_(carb))from this sectio... Cambrian System at the Shatan Section in northern Henan,North China,consists of sedimentary successions of tidal flat and shallow-water carbonate platform facies.Data of carbon isotope(δ^(13)C_(carb))from this section reveals five positive δ^(13)C_(carb)(P_(st-1)-P_(st-5))and five negative δ^(13)C_(carb) excursions(N_(st-1)-N_(st-5)).In the positive excursions,δ^(13)C_(carb) rises to 0.88‰,1.05‰,2.04‰,1.00‰ and 2.97‰,respectively,while in the negative excursions δ^(13)C_(carb) drops to -8.00‰,-3.50‰,-1.00‰,-0.33‰ and around -2.00‰,respectively.On the basis of chronostratigraphy of Cambrian,the most remarkable carbon isotope excursions can be correlated regionally and globally.In addition,one second-order and ten third-order sequences have been recognized at this section.Correlating third-order sequences and chemostratigraphy indicates that carbonates from the basal part of the transgression system tract(TST)and the upper part of the high-water system(LHST)generally have lighter δ^(13)C_(carb) values,whereas massive carbonates with microbialite from the lower part of the high-water system tract(EHST)usually have heavier δ^(13)C_(carb) values.The association of δ^(13)C_(carb) values with sea-level fluctuations suggests that the positive carbon isotope excursions or high δ^(13)C_(carb) values may have been caused by an increase in the marine primary productivity in response to maximum seawater flooding during the transgression. 展开更多
关键词 carbon isotope sedimentary rocks sea-level change shallow-water Cambrian System STRATIGRAPHY North China
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Carbonate Diagenesis Controlled by Glacioeustatic Sea-Level Changes: A Case Study from the Carboniferous-Permian Boundary Section at Xikou, China 被引量:3
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作者 张海军 丁林 +3 位作者 王训练 王雷 王清山 夏国英 《Journal of China University of Geosciences》 SCIE CSCD 2006年第2期103-114,共12页
The platform-facies carbonate rocks of the Carboniferous-Permian boundary strata are well developed and outcropped in Xikou (西口), Zhen'an (镇安) County, Shaanxi ( 陕西 ) Province, China. The carbonate diagenc... The platform-facies carbonate rocks of the Carboniferous-Permian boundary strata are well developed and outcropped in Xikou (西口), Zhen'an (镇安) County, Shaanxi ( 陕西 ) Province, China. The carbonate diagencsis in the Carboniferous-Permian boundary section at Xikou contains many processes with conspicuous effects, including micritization, cementation, mechanical and chemical compaction, neomorphism, and dissolution. Based on mineralogical composition and microfabrics, the diagenetic environments are distinguished into marine, near surface meteoric and burial environments. Detailed petrographical observation of abundant thin sections integrated with previous studies on sequence stratigraphy reveals that the carbonate diagenesis in the Carboniferous-Permian boundary section is related to the relative stratigraphic position of the rocks in the high-frequency cycles and controlled by the glacioeustatic sea-level changes. There are distinctive differences in diagenetic patterns between the lower transgressive sequence and the upper regressive sequence in a cyclothem. The diagenesis in the lower transgressive sequence is mainly characterized by pressure dissolution and recrystallization of mudstone and wackstone in a burial environment, and the diagenesis in the upper regressive sequence by cementation and leaching of freshwater in a meteoric environment. 展开更多
关键词 CARBONATE DIAGENESIS diagenetic environment high-frequency cycle glacioeustatic sealevel change Carboniferous-Permian boundary Zhen'an Shaanxi
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Transgressions and the sea-level changes of the western Taiwan Strait since the Late Pleistocene
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作者 Lan Dongzhao, Zhang Weilin, Chen Chenghui, Xie Zaituan, Yu Yongfen and Cai Feng Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1993年第4期617-627,共11页
The sedimentary sequences since the Late Pleistocene can be divided into Layers E, D, C, B, A from old to young according to systematic analysis of grain-size, pollen and spore, diatom, foraminifera, radiocarbon datin... The sedimentary sequences since the Late Pleistocene can be divided into Layers E, D, C, B, A from old to young according to systematic analysis of grain-size, pollen and spore, diatom, foraminifera, radiocarbon dating and paleogeomagnetism of 16 sedimentary cores from the sea area of the western Taiwan Strait. The results proved the existences of the Langqi transgression (upper section of Layer D) formed in middle and late stages of early Wurm glacial period, Fuzhou transgression (Layer C) formed in Wurm sub-interglacial period and Changle transgression (Layer A) formed in postglacial period. It was also the first time to discover the Jinmen transgression (Layer E) formed in Riss -Wurm interglacial period. In this paper it is proposed that most part of the Taiwan Strait emerged as land in the early stage of early Wurm glacial period, and was still under sublittoral environment in late Wurm glacial period, as well as the existence of Dongshan Continental Bridge was in 8×103 a BP. 展开更多
关键词 Taiwan Strait sedimentary sequence TRANSGRESSION sea-level change
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Sea-level changes controlled detrital sediment inputs to the Bicol Shelf in the western Philippine Sea since 150 ka 被引量:2
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作者 ZHANG Zhishun JIANG Fuqing +7 位作者 LI Tiegang YANG Dezhou ZHOU Xiaojing XIONG Zhifang QIU Xiaohua JIA Qi YAN Yu FENG Xuguang 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2020年第4期1153-1168,共16页
Detrital sediments derived from the Philippine Islands are one of the main sources of deep-sea sediments in the western Philippine Sea.However,systematic research on their characteristics and transport mechanisms are ... Detrital sediments derived from the Philippine Islands are one of the main sources of deep-sea sediments in the western Philippine Sea.However,systematic research on their characteristics and transport mechanisms are lacking.We used parametric end-member analysis to quantitatively partition the grain size of detrital sediments in core MD06-3052 from the Bicol Shelf in the western Philippine Sea;three endmembers EMI,EM2,and EM3,whose respective modes were at 2,10,and 45 μm,were separated.We also measured the Sr and Nd isotopic compositions of different size fractions(<4 and >20 μm) of the detrital sediments and the results showed that the detrital sediments mainly originate from the Philippine Islands.Components EMI and EM2 are transported to the Bicol Shelf mainly by surface and bottom currents from the islands,and component EM3 is delivered by gravity flow from the exposed shelf during low sea-level stands.The content of the total detrital fraction and the three end-members,as well as the mass accumulation rates(MARs) of the coarse detritus(EM2 and EM3),were considerably higher during glacial periods(40-14 ka and 150-130 ka) than during other intervals;the glacials corresponded to a low sea level,while the MAR of the fine detritus(EMI) did not increase remarkably during 40-14 ka.We therefore concluded that the input of coarse detritus to the Bicol Shelf from the islands was mainly controlled by sea-level change.Variations of the input of fine-grained detritus(EM1) was influenced not only by sea level but also by ocean currents and regional precipitation.Overall,our results help understand "source-to-sink" processes in the western Pacific marginal seas and their response to global change. 展开更多
关键词 Bicol Shelf late Pleistocene grain size sea level change
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Climate-environmental Deteriorations in a Greenhouse Earth System:Causes and Consequences of Short-Term Cretaceous Sea-Level Changes(a Report on IGCP 609)
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作者 Michael WAGREICH Benjamin SAMES HU Xiumian 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第S01期144-146,共3页
Anthropogenic global warming and resulting sea-level rise in response to enhanced atmospheric greenhouse gases and melting of the Earth’s continental ice shields have become issues of continuously growing interest fo... Anthropogenic global warming and resulting sea-level rise in response to enhanced atmospheric greenhouse gases and melting of the Earth’s continental ice shields have become issues of continuously growing interest for the scientific community as well as the public,pointing to threads of societies in a future greenhouse Earth System. 展开更多
关键词 sea-level change GREENHOUSE CRETACEOUS
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Postglacial sea-level changes and development stages of fluvial-estuarine system
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作者 Li Congxian Department of Marine Geology and Geophysics, Tongji University, Shanghai 200092, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1993年第4期573-584,共12页
-On the basis of the data obtained from the investigations on some rivers in China and Australia, the author discusses the spatial and temporal changes of various portions of fluvial-estuarine system during postglacia... -On the basis of the data obtained from the investigations on some rivers in China and Australia, the author discusses the spatial and temporal changes of various portions of fluvial-estuarine system during postglacial sea-level rising in present coastal and deltaic areas. The evolution of a fluvial-estuarine system can be divided into four development stages: early transgression, late transgression, stationary and regression. Early transgression brought about filling-in of the paleo-valley formed in low stand of sea level. In response to late transgression the estuaries were created, during the stationary stage the big swamp was developed. The regression led to estuaries to be filled with sediments and then became deltas. At the same locality the fluvial-estuarine system changed with time. In the transgressive period the lower reach of a river changed into an estuary, and then became nearshore area. In the regressive period the nearshore area changed into an estuary , and then became delta. 展开更多
关键词 sea-level fluvial-estuarine system postglacial period paleo-valley paleo-interfluve retrogressive aggrada-tion
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Exploring the spatiotemporal heterogeneity of vegetation changes in subtropical humid karst region under CO_(2)fertilization 被引量:1
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作者 CHEN Meng ZHOU Qiuwen +1 位作者 PENG Dawei YAN Weihong 《Journal of Geographical Sciences》 2025年第1期65-87,共23页
Terrestrial ecosystems heavily depend on vegetation,which responds to carbon dioxide(CO_(2))fertilization in hot and humid regions.The subtropical humid karst region is a hot and humid region;whether and to what exten... Terrestrial ecosystems heavily depend on vegetation,which responds to carbon dioxide(CO_(2))fertilization in hot and humid regions.The subtropical humid karst region is a hot and humid region;whether and to what extent CO_(2)fertilization affects vegetation changes in such regions remains unclear.In this study,we investigated the degree to which CO_(2)fertilization influences vegetation changes,along with their spatial and temporal differences,in the subtropical humid karst region using time-lag effect analysis,a random forest model,and multiple regression analysis.Results showed that CO_(2)fertilization plays an important role in vegetation changes,exhibiting clear spatial variations across different geomorphological zones,with its degree of influence ranging mainly between 11%and 25%.The highest contribution of CO_(2)fertilization was observed in the karst basin and non-karstic region,whereas the lowest contribution was found in the karst plateau region.Previous studies have primarily attributed vegetation changes in subtropical humid karst region to ecological engineering,leading to an overestimation of its contribution to these changes.The findings of this study enhance the understanding of the mechanism of vegetation changes in humid karst region and provide theoretical and practical insights for ecological and environmental protection in these regions. 展开更多
关键词 KARST vegetation changes NDVI driving factors carbon dioxide FERTILIZATION
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Changes in source contributions to the oxidative potential of PM_(2.5)in urban Xiamen,China 被引量:1
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作者 Jia-Min Li Si-Min Zhao +3 位作者 Qi-Yu Miao Shui-Ping Wu Jie Zhang James J.Schwab 《Journal of Environmental Sciences》 2025年第3期342-357,共16页
The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothr... The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothreitol assay,DTT)of PM_(2.5)were investigated in 2017/2018 and 2022 in Xiamen,China.The decrease rate of volume-normalized DTT(DTTv)(38%)was lower than that of PM_(2.5)(55%)between the two sampling periods.However,the mass-normalized DTT(DTTm)increased by 44%.Clear seasonal patterns with higher levels in winter were found for PM_(2.5),most chemical constituents and DTTv but not for DTTm.The large decrease in DTT activity(84%−92%)after the addition of EDTA suggested that watersoluble metals were the main contributors to DTT in Xiamen.The increased gap between the reconstructed and measured DTTv and the stronger correlations between the reconstructed/measured DTT ratio and carbonaceous species in 2022were observed.The decrease rates of the hazard index(32.5%)and lifetime cancer risk(9.1%)differed from those of PM_(2.5)and DTTv due to their different main contributors.The PMF-MLR model showed that the contributions(nmol/(min·m^(3)))of vehicle emission,coal+biomass burning,ship emission and secondary aerosol to DTTv in 2022 decreased by 63.0%,65.2%,66.5%,and 22.2%,respectively,compared to those in 2017/2018,which was consistent with the emission reduction of vehicle exhaust and coal consumption,the adoption of low-sulfur fuel oil used on board ships and the reduced production of WSOC.However,the contributions of dust+sea salt and industrial emission increased. 展开更多
关键词 Chemical composition Oxidative potential Interannual change PMF-MLR Source apportionment
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Macular microvascular and structural changes on optical coherence tomography angiography in atypical optic neuritis 被引量:1
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作者 Chinmay Mahatme Madhurima Kaushik +2 位作者 Veerappan Rathinasabapathy Saravanan Karthik Kumar Virna M Shah 《World Journal of Methodology》 2025年第1期88-94,共7页
BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic im... BACKGROUND Atypical optic neuritis,consisting of neuromyelitis optica spectrum disorders(NMOSD)or myelin oligodendrocyte glycoprotein antibody disease(MOGAD),has a very similar presentation but different prognostic implications and longterm management strategies.Vascular and metabolic factors are being thought to play a role in such autoimmune neuro-inflammatory disorders,apart from the obvious immune mediated damage.With the advent of optical coherence tomography angiography(OCTA),it is easy to pick up on these subclinical macular microvascular and structural changes.AIM To study the macular microvascular and structural changes on OCTA in atypical optic neuritis.METHODS This observational cross-sectional study involved 8 NMOSD and 17 MOGAD patients,diagnosed serologically,as well as 10 healthy controls.Macular vascular density(MVD)and ganglion cell+inner plexiform layer thickness(GCIPL)were studied using OCTA.RESULTS There was a significant reduction in MVD in NMOSD and MOGAD affected as well as unaffected eyes when compared with healthy controls.NMOSD and MOGAD affected eyes had significant GCIPL thinning compared with healthy controls.NMOSD unaffected eyes did not show significant GCIPL thinning compared to healthy controls in contrast to MOGAD unaffected eyes.On comparing NMOSD with MOGAD,there was no significant difference in terms of MVD or GCIPL in the affected or unaffected eyes.CONCLUSION Although significant microvascular and structural changes are present on OCTA between atypical optic neuritis and normal patients,they could not help in differentiating between NMOSD and MOGAD cases. 展开更多
关键词 Optical coherence tomography angiography Atypical optic neuritis Macular microvascular changes Neuromyelitis optica spectrum disorders Myelin oligodendrocyte glycoprotein antibody disorder
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Relationship between longitudinal changes in lipid composition and ischemic stroke among hypertensive patients
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作者 Cheng-Cheng Wei Yu-Qing Huang Cheng-Hong Yu 《World Journal of Clinical Cases》 SCIE 2025年第4期18-27,共10页
BACKGROUND Dyslipidemia was strongly linked to stroke,however the relationship between dyslipidemia and its components and ischemic stroke remained unexplained.AIM To investigate the link between longitudinal changes ... BACKGROUND Dyslipidemia was strongly linked to stroke,however the relationship between dyslipidemia and its components and ischemic stroke remained unexplained.AIM To investigate the link between longitudinal changes in lipid profiles and dyslipidemia and ischemic stroke in a hypertensive population.METHODS Between 2013 and 2014,6094 hypertension individuals were included in this,and ischemic stroke cases were documented to the end of 2018.Longitudinal changes of lipid were stratified into four groups:(1)Normal was transformed into normal group;(2)Abnormal was transformed into normal group;(3)Normal was transformed into abnormal group;and(4)Abnormal was transformed into abnormal group.To examine the link between longitudinal changes in dyslipidemia along with its components and the risk of ischemic stroke,we utilized multivariate Cox proportional hazards models with hazard ratio(HR)and 95%CI.RESULTS The average age of the participants was 62.32 years±13.00 years,with 329 women making up 54.0%of the sample.Over the course of a mean follow-up of 4.8 years,143 ischemic strokes happened.When normal was transformed into normal group was used as a reference,after full adjustments,the HR for dyslipidemia and ischemic stroke among abnormal was transformed into normal group,normal was transformed into abnormal group and abnormal was transformed into abnormal Wei CC et al.Dyslipidemia changed and ischemic stroke WJCC https://www.wjgnet.com 2 February 6,2025 Volume 13 Issue 4 group were 1.089(95%CI:0.598-1.982;P=0.779),2.369(95%CI:1.424-3.941;P<0.001)and 1.448(95%CI:1.002-2.298;P=0.047)(P for trend was 0.233),respectively.CONCLUSION In individuals with hypertension,longitudinal shifts from normal to abnormal in dyslipidemia-particularly in total and low-density lipoprotein cholesterol-were significantly associated with the risk of ischemic stroke. 展开更多
关键词 Longitudinal change HYPERTENSION DYSLIPIDEMIA Lipid profile Ischemic stroke
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Dynamic changes of gravity field before the Luding Ms6.8 earthquake and its crustal material migration characteristics
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作者 Qingqing Tan Chongyang Shen +5 位作者 Jiapei Wang Xiong Yang Wen Jin Minghui Zhang Hongbo Tan Guangliang Yang 《Geodesy and Geodynamics》 2025年第2期214-222,共9页
On September 5, 2022, an earthquake of magnitude M_(S)6.8 occurred in Luding County, Sichuan Province.This earthquake occurred at the key part of the southeast-clockwise extrusion of material on the eastern margin of ... On September 5, 2022, an earthquake of magnitude M_(S)6.8 occurred in Luding County, Sichuan Province.This earthquake occurred at the key part of the southeast-clockwise extrusion of material on the eastern margin of the Qinghai Plateau, the Y-shaped confluence of the Xianshuihe, Longmenshan and Anninghe fault zones. In this study, the three-dimensional dynamic crustal density changes in the earthquake area are obtained by the typical gravity change data from 2019 to 2022 before the earthquake and gravity inversion by growing bodies. The results indicate that gravity changes presented an obvious fourquadrant and gradient belt distribution in the Luding area before the earthquake. The threedimensional density horizontal slices show that small density changes occurred at the epicenter in the mid-to-upper crust between 2019.9-2020.9 and 2019.9-2021.9. At the same time, the surrounding areas exhibited a positive and negative quadrant distribution. These observations indicate that the source region was likely in a stable locked state, with locking-in shear forces oriented in the NW and NE directions. From 2021.9 to 2022.8, the epicentral region showed negative density changes, indicating that the source region was in the expansion stage, approaching a near-seismic state. The three-dimensional density vertical slices reveal a southeastward migration of positive and negative densities near the epicenter and on the western of the Xianshuihe Fault Zone, indicating that the material is flowing out to the southeast. The observed local negative density changes at the epicenter along the Longmenshan Fault Zone are likely associated with the NE-oriented extensional stress shown by the seismic source mechanism. The above results can provide a basis for interpreting pre-earthquake gravity and density changes,thereby contributing to the advancement of earthquake precursor theory. 展开更多
关键词 Luding earthquake Gravity changes Three-dimensional density changes Gravity inversion
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Runoff changes and influencing factors in the Nyang River Basin in Xizang
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作者 CAO Liang DONG Shi +2 位作者 WANG Yuyan LI Xingran CAO Pengxi 《Journal of Mountain Science》 2025年第10期3706-3720,共15页
This study aims to construct a large-scale hydrological Variable Infiltration Capacity(VIC)model based on temperature and precipitation at high altitudes,while elucidating the applicability of the model for hydrologic... This study aims to construct a large-scale hydrological Variable Infiltration Capacity(VIC)model based on temperature and precipitation at high altitudes,while elucidating the applicability of the model for hydrological simulation and analyzing the factors affecting runoff volume.Runoff volume and runoff depth were simulated using the VIC model and its performance was evaluated.Meanwhile,the factors affecting runoff volume were analyzed using Spearman correlation.The following model sensitivity parameters were obtained based on the China Natural Runoff Grid Point Dataset(CNRD v1.0):The variable infiltration curve parameter was 0.3,the Dsmax fraction where non-linear baseflow begins was 0.02,the maximum baseflow velocity was 15 mm/d,the maximum soil moisture where non-linear baseflow occurred was 0.7,the second soil moisture layer thickness was 0.3,and the thickness of the third soil moisture layer was 1.5.The surface runoff values in the Nyang River basin were similar in the first and fourth quarters(1.05–2.27 mm and 2.38–4.77 mm,respectively),and the surface runoff values were similar in the second and third quarters when the surface runoff was greater(23.46–52.20 mm and 60.59–85.63 mm,respectively).Watershed area,temperature,and precipitation significantly influenced the amount of runoff from the Nyang River.The applicability of the model to the Nyang River basin was confirmed using two different rate models.In some areas,precipitation and temperature did not have a dominating influence on runoff.Although the VIC model has significant advantages in runoff simulation,it requires a wealth of meteorological,soil,and hydrological data that may be difficult to obtain in some areas. 展开更多
关键词 Runoff changes Nyang river VIC model Meteorological changes Spearman correlation
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Spatiotemporal Variations in Climatic Factors,Catchment Characteristic Induced Runoff Changes with Multi-Time Scales across the Contiguous United States
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作者 Xinglong Gong Shuping Du +1 位作者 Fengyu Li Yibo Ding 《Journal of Earth Science》 2025年第1期146-160,共15页
Previous works were mainly concentrated on long-term average runoff alterations,and extreme temperatures and watershed conditions are little analyzed.In this study,we collected gauged river flow and meteorological dat... Previous works were mainly concentrated on long-term average runoff alterations,and extreme temperatures and watershed conditions are little analyzed.In this study,we collected gauged river flow and meteorological data time series from 1916 to 2015 and 1941 to 2015 across the contiguous United States(CONUS)for 188 catchments to investigate the temporal trends and spatial features of runoff changes at multi-time scales.We also analyzed the relationships between runoff changes and climatic factors.Median descriptive statistics and Budyko coupled climate elasticity methods were used to calculate runoff elasticity in each time scale.The original Mann-Kendall trend test was used to test their trend significance in four time-scale(11,20,40,and 60 a),respectively.The results show that the trend of runoff changes is more significant in high time scales;total changes are heterogeneous over CONUS.After the 1970s,increases of up to 27%decade-1 were mainly concentrated in the mid-northern regions.Maximum temperature and catchment characteristics are vital factors for runoff alteration;runoff changes are independent of rainfall,and wet regions tend to have lower changes.These findings could help develop better regional water resource planning and management. 展开更多
关键词 catchment characteristics climate change slipping window runoff changes trend analysis runoff elasticity
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Historical and future climate changes impact global solar photovoltaic power potential:Role of key meteorological variables
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作者 Chang Liu Lei Chen +4 位作者 Ke Li Xipeng Jin Xi Chen Wenhao Qiao Hong Liao 《Atmospheric and Oceanic Science Letters》 2025年第6期58-64,共7页
Renewable energy,especially solar power,is vital for mitigating global warming,while climate change also impacts solar photovoltaic potential(PVpot).This study analyzes historical(1985–2014)and future(2015–2100)clim... Renewable energy,especially solar power,is vital for mitigating global warming,while climate change also impacts solar photovoltaic potential(PVpot).This study analyzes historical(1985–2014)and future(2015–2100)climate effects on PVpot,and quantifies contributions from changed radiation,temperature,and wind speed.Historically,global PVpot increased by 0.42‰,with notable rises in eastern China(+7.1‰)and southern Europe(+3.5‰).By the end of the century,increased radiation-induced PVpot(+1.27‰)offsets temperatureinduced PVpot loss(−0.54‰)under SSP1-2.6,yielding a net PVpot increase(+0.74‰).Under SSP2-4.5,the temperature-induced PVpot decline(−1.50‰)drives the final PVpot reduction(−1.15‰).Under SSP3-7.0 and SSP5-8.5,combined radiation-induced(−1.94‰and−1.99‰)and temperature-induced PVpot changes(−2.67‰and−3.41‰)result in significant PVpot declines(−4.57‰and−5.31‰).Regional analysis reveals that eastern China(+0.7‰to+8.6‰),southern Europe(+0.3‰to+2.5‰),and Northwest South America(+0.6‰to+2.1‰)retain positive changes in future PVpot across all climate scenarios,which may be due to reduced aerosols and cloud cover,suggesting these areas can remain suitable for photovoltaic installations despite climate changes.In contrast,temperature-driven PVpot declines over the Qinghai-Tibet Plateau(−9.1‰to−4.3‰)and northern Africa(−9.3‰to−4.9‰)under future high-emission scenarios indicate that these historically advantageous regions will become less suitable for solar energy deployment.The findings underscore that climate changes driven by sustainable development pathways will generate more PVpot in the future for better global warming mitigation. 展开更多
关键词 Solar photovoltaic power potential Climate change Meteorological impact Historical and future change
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Adaptive evolution of BMP4 as a potential mechanism for flipper forelimb changes in cetaceans
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作者 Yao Liu Luo-Ying Deme +2 位作者 Jia Liu Shi-Xia Xu Guang Yang 《Zoological Research》 2025年第3期675-683,共9页
Vertebrate limbs have undergone profound morphological diversification,enabling adaptations to a broad spectrum of ecological niches.In marine mammals,the evolution of highly specialized flipper-like forelimbs represe... Vertebrate limbs have undergone profound morphological diversification,enabling adaptations to a broad spectrum of ecological niches.In marine mammals,the evolution of highly specialized flipper-like forelimbs represents a profound structural transformation associated with aquatic habitats.This adaptation has been hypothesized to result,in part,from the inhibition of interphalangeal cell apoptosis during limb development,although the underlying genetic mechanism remains poorly understood.This study investigated the evolutionary dynamics and functional consequences of three key bone morphogenetic protein genes,BMP2,BMP4,and BMP7,which regulate apoptosis in interphalangeal mesenchymal stromal cells during embryonic limb development to ensure proper differentiation of interphalangeal tissues.Comparative genomic analysis revealed significantly accelerated evolution for BMP4 and BMP7 in the cetacean ancestral lineage,with two positively selected sites(V79I and H247R)involved in cetacean-specific amino acid substitutions located in the TGF-βpropeptide functional domain in BMP4.In vitro assays confirmed that cetacean-specific BMP4 mutations significantly disrupted normal cell apoptosis and proliferation and altered the transcription and protein expression of downstream apoptosis-related factors,including cytochrome c(Cyt c),BCL2 associated X,and B-cell lymphoma 2,within the BMP signaling pathway.The significant influence of BMP4 mutations on apoptotic inhibition highlights a potential role in the development of limb bud mesenchymal tissue and the emergence of the flipper forelimb phenotype in cetaceans. 展开更多
关键词 CETACEANS Flipper limb BMP4 Functional change
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Effects of Future Climate and Cropland Use Changes on Rice Potential Yields in Hainan Island, China
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作者 PU Luoman XIANG Mengjun 《Chinese Geographical Science》 2025年第3期438-453,共16页
Rapid climate and cropland use changes in recent decades have posed major challenges to food security in China.Hainan Is-land is the only tropical island in China and is blessed with natural conditions for crop produc... Rapid climate and cropland use changes in recent decades have posed major challenges to food security in China.Hainan Is-land is the only tropical island in China and is blessed with natural conditions for crop production.This study first simulates the climate scenarios of Hainan Island for 2030,2040 and 2050 under the four Socio-economic Pathways(SSPs)based on the climate models in ScenarioMIP of Coupled Model Intercomparison Project Phase 6(CMIP6),and then simulates the land use scenarios of Hainan Island for 2030,2040 and 2050 based on the Cellular Automata(CA)-Markov model.Finally,based on the Global Agro-Ecological Zones(GAEZ)model,the rice potential yield in Hainan Island for 2030,2040 and 2050 are simulated,and the effects of future climate and cropland use changes on rice potential yields are investigated.The results show that:1)from 2020 to 2050,mean maximum temperature first decreases and then increases,while mean minimum temperature increase sharply followed by a leveling off under the four SSPs.Precipitation decreases and then increases under other three SSPs except SSP2-4.5.Net solar radiation increases continuously under SSP1-2.6,2-4.5,and 5-8.5,and has the lowest simulated values under SSP3-7.0.Mean wind speed increases continuously under SSP1-2.6,fluctuates more under SSP2-4.5 and SSP5-8.5,and increases slowly and then decreases sharply under SSP3-7.0.Relative humidity basically decreases continuously under the four SSPs.2)Areas of paddy field are 302.49 thousand,302.41 thousand and 302.71 thou-sand ha for 2030,2040 and 2050,respectively,all less than that in 2020.Paddy field is mainly converted into built-up land and wood-land.As for the conversion of other land types to paddy field,woodland is the main source.3)Under the effects of future climate and cropland use changes,the mean potential productions in Hainan Island under the four SSPs increase 1.17 million,1.13 million and 1.11 million t,respectively,and the mean potential yields increase 3873.21,3766.71 and 3672.38 kg/ha,respectively for the three periods.The largest increases in mean rice potential production and mean potential yield are 1.21 million t and 4008.00 kg/ha,1.16 million t and 3846.65 kg/ha,as well as 1.13 million t and 3732.75 kg/ha,respectively under SSP 3-7.0,indicating that SSP3-7.0 is the most suitable scenario for rice growth.This study could provide scientific basis for crop planting planning and agricultural policy adjustment. 展开更多
关键词 rice potential yield climate change cropland use change Global Agro-Ecological Zones(GAEZ)model CA-Markov mod-el Hainan Island China
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