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Fern Diversity in the Mid-Cretaceous Amber Forests Revealed by Exceptionally Preserved Sporangium Types
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作者 chunxiang li Xile Zhou Yiran Wang 《International Journal of Geosciences》 CAS 2024年第5期351-365,共15页
The amber deposits from the Albian-Cenomanian in Myanmar have emerged as a pivotal source for exceptionally abundant fossil insect fauna since their initial discovery. Recent studies have increasingly focused on eluci... The amber deposits from the Albian-Cenomanian in Myanmar have emerged as a pivotal source for exceptionally abundant fossil insect fauna since their initial discovery. Recent studies have increasingly focused on elucidating the fern inventory and examining newly available fossils from Myanmar amber, suggesting a diverse fern flora that once thrived in Cretaceous forests. Through investigations of amber collections, with particular emphasis on sporangium structures—especially the annulus types preserved in amber inclusions—this study revealed additional novelties within the Cyatheales and Schizaeales in mid-Cretaceous Myanmar amber forests. The described specimens and newly discovered fossils provide compelling evidence that Polypodiales were not only diverse and abundant but also that other fern lineages, such as Cyatheales and Schizaeales, coexisted in these ancient forest ecosystems. This study reveals the high diversity of ferns in the mid-Cretaceous Myanmar area, while also implying the paleoecological and paleogeographical significance of the Mesozoic Burmese amber forests. 展开更多
关键词 MID-CRETACEOUS Myanmar Amber Polypodiales Cyatheales Schizaeales Sporangium
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Inferring Eupolypods Divergence Time Using Bayesian Tip-Dating
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作者 Yiran Wang chunxiang li 《Open Journal of Geology》 CAS 2024年第2期247-258,共12页
According to the most recent Pteridophyte Phylogeny Group (PPG), eupolypods, or eupolypod ferns, are the most differentiated and diversified of all major lineages of ferns, accounting for more than half of extant fern... According to the most recent Pteridophyte Phylogeny Group (PPG), eupolypods, or eupolypod ferns, are the most differentiated and diversified of all major lineages of ferns, accounting for more than half of extant fern diversity. However, the evolutionary history of eupolypods remains incompletely understood, and conflicting ideas and scenarios exist in the literature about many aspects of this history. Due to a scarce fossil record, the diversification time of eupolypods mainly inferred from molecular dating approaches. Currently, there are two molecular dating results: the diversification of eupolypods occurred either in the Late Cretaceous or as early as in the Jurassic. This study uses the Bayesian tip-dating approach for the first time to infer the diversification time for eupolypods. Our analyses support the Jurassic diversification for eupolypods. The age estimations for the diversifications of the whole clade and one of its two subclades (the eupolypods II) are both in the Jurassic, which adds to the growing body of data on a much earlier diversification of Polypodiales in the Mesozoic than previously suspected. 展开更多
关键词 Eupolypods MID-CRETACEOUS FOSSILS Bayesian Tip-Dating
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The Nature and Predictability of the East Asian Extreme Cold Events of 2020/21 被引量:5
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作者 Guokun DAI chunxiang li +2 位作者 Zhe HAN Dehai LUO Yao YAO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第4期566-575,共10页
Three extreme cold events invaded China during the early winter period between December 2020 to mid-January 2021 and caused drastic temperature drops,setting new low-temperature records at many stations during 6−8 Jan... Three extreme cold events invaded China during the early winter period between December 2020 to mid-January 2021 and caused drastic temperature drops,setting new low-temperature records at many stations during 6−8 January 2021.These cold events occurred under background conditions of low Arctic sea ice extent and a La Niña event.This is somewhat expected since the coupled effect of large Arctic sea ice loss in autumn and sea surface temperature cooling in the tropical Pacific usually favors cold event occurrences in Eurasia.Further diagnosis reveals that the first cold event is related to the southward movement of the polar vortex and the second one is related to a continent-wide ridge,while both the southward polar vortex and the Asian blocking are crucial for the third event.Here,we evaluate the forecast skill for these three events utilizing the operational forecasts from the ECMWF model.We find that the third event had the highest predictability since it achieves the best skill in forecasting the East Asian cooling among the three events.Therefore,the predictability of these cold events,as well as their relationships with the atmospheric initial conditions,Arctic sea ice,and La Niña deserve further investigation. 展开更多
关键词 extreme cold event PREDICTABILITY Arctic atmospheric initial conditions Arctic sea ice La Niña
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Mechanical Properties of Lime-Fly Ash-Sulphate Aluminum Cement Stabilized Loess
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作者 liang Jia chunxiang li Jian Guo 《Journal of Renewable Materials》 SCIE EI 2020年第10期1357-1373,共17页
Lime-fly ash stabilized loess has a poor early strength,which results in a later traffic opening time when it is used as road-base materials.Consideration of the significant early strength characteristics of sulphate ... Lime-fly ash stabilized loess has a poor early strength,which results in a later traffic opening time when it is used as road-base materials.Consideration of the significant early strength characteristics of sulphate aluminum cement(SAC),it is always added into the lime-fly ash mixtures to improve the early strength of stabilized loess.However,there is a scarcity of research on the mechanical behavior of lime-fly ash-SAC stabilized loess and there is a lack of quantitative evaluation of loess stabilized with binder materials.This research explored the effects of the amount of binder materials,curing time and porosity on the unconfined compressive strength(UCS),splitting tensile strength(STS),cohesion(c)and friction angle(φ)of lime-fly ash-SAC stabilized loess by a series of unconfined compressive tests(UCT)and splitting tensile tests(STT).The results indicate that an increase in curing time and a decrease in porosity lead to a continuous increase in the UCS and STS for lime-fly ash-SAC stabilized loess.The addition of SAC has a prominent enhancement in the early strength of lime-fly ash-SAC stabilized loess.When the curing time,porosity,and binder content were constant,the UCS and STS increase with increasing SAC content;For a stabilized loess with 30%binder content and 5%SAC content after 1 day of curing,the UCS was greater than 0.7 MPa,which meets the requirement of opening traffic,so lime-fly ash-SAC stabilized loess could be used as an excellent maintenance material for road-base;In accordance with the analysis of testing data,empirical relationships between the UCS and STS of lime-fly-SAC stabilized loess and key effect factors(binder materials content,curing time and porosity)were developed,which can provide references for reasonably selecting the amount of binder materials,compaction degree and curing period to meet the required strength of practical engineering.Finally,based on the Mohr-Coulomb theory and the above empirical relationships,a simpler method for calculating the c andφof stabilized loess was proposed,with which,the shear strength parameters can be determined only by UCT or STT. 展开更多
关键词 LOESS sulphate aluminum cement unconfined compressive strength splitting tensile strength
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The Influence of Arctic Sea Ice Concentration Perturbations on Subseasonal Predictions of North Atlantic Oscillation Events
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作者 Guokun DAI Mu MU +4 位作者 Zhe HAN chunxiang li Zhina JIANG Mengbin ZHU Xueying MA 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第12期2242-2261,I0009-I0015,共27页
The influence of Arctic sea ice concentration (SIC) on the subseasonal prediction of the North Atlantic Oscillation (NAO) event is investigated by utilizing the Community Atmospheric Model version 4. The optimal Arcti... The influence of Arctic sea ice concentration (SIC) on the subseasonal prediction of the North Atlantic Oscillation (NAO) event is investigated by utilizing the Community Atmospheric Model version 4. The optimal Arctic SIC perturbations which exert the greatest influence on the onset of an NAO event from a lead of three pentads (15 days) are obtained with a conditional nonlinear optimal perturbation approach. Numerical results show that there are two types of optimal Arctic SIC perturbations for each NAO event, with one weakening event (marked as type-1) and another strengthening event (marked as type-2). For positive NAO events, type-1 optimal SIC perturbations mainly show positive SIC anomalies in the Greenland, Barents, and Okhotsk Seas, while type-2 perturbations mainly feature negative SIC anomalies in these regions. For negative NAO events, the optimal SIC perturbations have almost opposite patterns to those in positive events, although there are some differences among these SIC perturbations due to different atmospheric initial conditions. Further diagnosis reveals that the optimal Arctic SIC perturbations first modify the surface turbulent heat flux and the temperature in the lower troposphere via diabatic processes. Afterward, the temperature in the low troposphere is mainly affected by dynamic advection. Finally, potential vorticity advection plays a crucial role in the 500-hPa geopotential height prediction in the northern North Atlantic sector during pentad 4, which influences NAO event prediction. These results highlight the importance of Arctic SIC on NAO event prediction and the spatial characteristics of the SIC perturbations may provide scientific support for target observations of SIC in improving NAO subseasonal predictions. 展开更多
关键词 optimal Arctic SIC perturbation NAO event subseasonal prediction CNOP approach
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Influence of Arctic Sea-ice Concentration on Extended-range Forecasting of Cold Events in East Asia
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作者 chunxiang li Guokun DAI +5 位作者 Mu MU Zhe HAN Xueying MA Zhina JIANG Jiayu ZHENG Mengbin ZHU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第12期2224-2241,共18页
Utilizing the Community Atmosphere Model,version 4,the influence of Arctic sea-ice concentration(SIC)on the extended-range prediction of three simulated cold events(CEs)in East Asia is investigated.Numerical results s... Utilizing the Community Atmosphere Model,version 4,the influence of Arctic sea-ice concentration(SIC)on the extended-range prediction of three simulated cold events(CEs)in East Asia is investigated.Numerical results show that the Arctic SIC is crucial for the extended-range prediction of CEs in East Asia.The conditional nonlinear optimal perturbation approach is adopted to identify the optimal Arctic SIC perturbations with the largest influence on CE prediction on the extended-range time scale.It shows that the optimal SIC perturbations are more inclined to weaken the CEs and cause large prediction errors in the fourth pentad,as compared with random SIC perturbations under the same constraint.Further diagnosis reveals that the optimal SIC perturbations first modulate the local temperature through the diabatic process,and then influence the remote temperature by horizontal advection and vertical convection terms.Consequently,the optimal SIC perturbations trigger a warming center in East Asia through the propagation of Rossby wave trains,leading to the largest prediction uncertainty of the CEs in the fourth pentad.These results may provide scientific support for targeted observation of Arctic SIC to improve the extended-range CE prediction skill. 展开更多
关键词 cold event Arctic sea-ice concentration extended-range prediction
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TGF-βsignaling in health,disease,and therapeutics
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作者 Ziqin Deng Tao Fan +4 位作者 Chu Xiao He Tian Yujia Zheng chunxiang li Jie He 《Signal Transduction and Targeted Therapy》 SCIE CSCD 2024年第4期1466-1505,共40页
ransforming growth factor(TGF)-βis a multifunctional cytokine expressed by almost every tissue and cell type.The signal transduction of TGF-βcan stimulate diverse cellular responses and is particularly critical to e... ransforming growth factor(TGF)-βis a multifunctional cytokine expressed by almost every tissue and cell type.The signal transduction of TGF-βcan stimulate diverse cellular responses and is particularly critical to embryonic development,wound healing,tissue homeostasis,and immune homeostasis in health.The dysfunction of TGF-βcan play key roles in many diseases,and numerous targeted therapies have been developed to rectify its pathogenic activity.In the past decades,a large number of studies on TGF-βsignaling have been carried out,covering a broad spectrum of topics in health,disease,and therapeutics.Thus,a comprehensive overview of TGF-βsignaling is required for a general picture of the studies in this field.In this review,we retrace the research history of TGF-βand introduce the molecular mechanisms regarding its biosynthesis,activation,and signal transduction.We also provide deep insights into the functions of TGF-βsignaling in physiological conditions as well as in pathological processes.TGF-β-targeting therapies which have brought fresh hope to the treatment of relevant diseases are highlighted.Through the summary of previous knowledge and recent updates,this review aims to provide a systematic understanding of TGF-βsignaling and to attract more attention and interest to this research area. 展开更多
关键词 HOMEOSTASIS HEALING WOUND
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植物雌激素防治激素依赖性肿瘤研究进展 被引量:2
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作者 柯有甫 高文谦 +3 位作者 曾乐谦 李春香 魏克民 郑军献 《世界肿瘤研究》 2013年第2期13-16,共4页
探究植物雌激素防治激素依赖性肿瘤的文献发现:植物雌激素是来源于植物的杂环多酚类天然化合物,包括黄酮类、木脂素类、香豆素类、二苯乙烯类、醌类、三萜类、甾醇类、真菌雌激素类等。其雌激素活性较雌二醇低,有雌激素或抗雌激素双向... 探究植物雌激素防治激素依赖性肿瘤的文献发现:植物雌激素是来源于植物的杂环多酚类天然化合物,包括黄酮类、木脂素类、香豆素类、二苯乙烯类、醌类、三萜类、甾醇类、真菌雌激素类等。其雌激素活性较雌二醇低,有雌激素或抗雌激素双向调节作用,对激素相关性疾病具有广泛防治作用。实验与临床研究显示:植物雌激素对乳腺癌、卵巢癌、子宫内膜癌、前列腺癌(包括良性前列腺增生)、结肠癌等激素依赖性肿瘤有防治作用。其机制为直接参与机体的内分泌调节、抗氧化、抑制肿瘤血管新生、抑制肿瘤转移、抑制癌基因表达、促进抑癌基因表达、诱导肿瘤细胞凋亡、抑制肿瘤生长与增殖等。含植物雌激素的中药很多,植物雌激素防治激素依赖性肿瘤应用前景广阔。 展开更多
关键词 植物雌激素 雌激素受体 雌激素样活性 激素依赖性肿瘤 中药
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Evaluation of Surface Relative Humidity in China from the CRA-40 and Current Reanalyses 被引量:4
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作者 Jingpeng ZHANG Tianbao ZHAO +6 位作者 Zhi li chunxiang li Zhen li Kairan YING chunxiang SHI lipeng JIANG Wenyu ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第11期1958-1976,共19页
Recently,the China Meteorological Administration(CMA)released a new Global Atmospheric Reanalysis(CRA-40)dataset for the period 1979−2018.In this study,surface relative humidity(RH)from CRA-40 and other current reanal... Recently,the China Meteorological Administration(CMA)released a new Global Atmospheric Reanalysis(CRA-40)dataset for the period 1979−2018.In this study,surface relative humidity(RH)from CRA-40 and other current reanalyses(e.g.,CFSR,ERA5,ERA-Interim,JRA-55,and MERRA-2)is comprehensively evaluated against homogenized observations over China.The results suggest that most reanalyses overestimate the observations by 15%−30%(absolute difference)over the Tibetan Plateau but underestimate the observations by 5%−10%over most of northern China.The CRA-40 performs relatively well in describing the long-term change and variance seen in the observed surface RH over China.Most of the reanalyses reproduce the observed surface RH climatology and interannual variations well,while few reanalyses can capture the observed long-term RH trends over China.Among these reanalyses,the CFSR does poorly in describing the interannual changes in the observed RH,especially in Southwest China.An empirical orthogonal function(EOF)analysis also suggests that the CRA-40 performs better than other reanalyses to capture the first two leading EOF modes revealed by the observations.The results of this study are expected to improve understanding of the strengths and weaknesses of the current reanalysis products and thus facilitate their application. 展开更多
关键词 surface relative humidity CRA-40 reanalysis current reanalysis EVALUATION
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CXXC finger protein 1 (CFP1) bridges the reshaping of genomic H3K4me3 signature to the advancement of lung adenocarcinoma
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作者 Tao Fan Chu Xiao +5 位作者 Hengchang liu Yu liu liyu Wang He Tian chunxiang li Jie He 《Signal Transduction and Targeted Therapy》 SCIE CSCD 2023年第10期5010-5022,共13页
Histone H3 lysine 4 trimethylation(H3K4me3)is a canonical chromatin modification associated with active gene transcription,playing a pivotal role in regulating various cellular functions.Components of the H3K4me3 meth... Histone H3 lysine 4 trimethylation(H3K4me3)is a canonical chromatin modification associated with active gene transcription,playing a pivotal role in regulating various cellular functions.Components of the H3K4me3 methyltransferase complex,known as the proteins associated with SET1(COMPASS),have been implicated in exerting cancer-protective or cancer-inhibitory effects through inducive H3K4me3 modification.However,the role of the indispensable non-catalytic component of COMPASS CXXC-type zinc finger protein 1(CFP1)in malignant progression remains unclear. 展开更多
关键词 protective H3K4me3 BRIDGES
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Evaluation of Daily Precipitation Product in China from the CMA Global Atmospheric Interim Reanalysis 被引量:15
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作者 chunxiang li Tianbao ZHAO +1 位作者 chunxiang SHI Zhiquan liU 《Journal of Meteorological Research》 SCIE CSCD 2020年第1期117-136,1-4,共24页
The China Meteorological Administration(CMA)recently produced a CMA Global Atmospheric Interim Reanalysis(CRAI)dataset for the years 2007–2016.A comprehensive evaluation of the ability of CRAI to capture the spatiote... The China Meteorological Administration(CMA)recently produced a CMA Global Atmospheric Interim Reanalysis(CRAI)dataset for the years 2007–2016.A comprehensive evaluation of the ability of CRAI to capture the spatiotemporal variability of observed precipitation,in terms of both mean states and extreme indicators over China,is performed.Comparisons are made with other current reanalysis datasets,namely,the ECMWF interim reanalysis(ERAI),Japanese 55-yr reanalysis(JRA55),NCEP Climate Forecast System Reanalysis(CFSR),and NASA Modern-Era Retrospective analysis for Research and Applications version 2(MERRA2),as well as NCEP Climate Prediction Center(CPC)observations.The results show that,for daily variations of rainfall during warm seasons in eastern China,CRAI and CFSR overestimate the precipitation of the main rain belt,while the overestimation is confined to the area south of 25°N in JRA55 but north of 24°N in MERRA2;whereas ERAI tends to underestimate the precipitation in most regions of eastern China.Two extreme metrics,the total amount of precipitation on days where daily precipitation exceeds the 95 th percentile(R95 pTOT)and the number of consecutive dry days(CDDs)in one month,are examined to assess the performance of reanalysis datasets.In terms of extreme events,CRAI,ERAI,and JRA55 tend to underestimate the R95 pTOT in most of eastern China,whereas more frequent extreme rainfall can be found in most regions of China in both CFSR and MERRA2;and all of the reanalyses underestimate the CDDs.Among the reanalysis products,CRAI and JRA55 show better agreement with the observed R95 pTOT than the other datasets,with fewer biases,higher correlation coefficients,and much more similar linear trend patterns,while ERAI stands out in better capturing the amount and temporal variations of the observed CDDs. 展开更多
关键词 China METEOROLOGICAL Administration(CMA) the CMA GLOBAL ATMOSPHERIC Interim Reanalysis(CRAI) precipitation DAILY
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Ancient Y-DNA with reconstructed phylogeny provides insights into the demographic history of paternal haplogroup N1a2-F1360 被引量:1
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作者 Pengcheng Ma Xuan Yang +7 位作者 Shi Yan chunxiang li Shizhu Gao Binghua Han Kan Hou Martine Robbeets Lan-Hai Wei Yinqiu Cui 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2021年第12期1130-1133,共4页
Northern Eurasia (nEA) has been considered crucial for the dispersal of the anatomically modern human (AMH) in recent studies.After the Last Glacial Maximum (LGM),ancient populations from different locations were redi... Northern Eurasia (nEA) has been considered crucial for the dispersal of the anatomically modern human (AMH) in recent studies.After the Last Glacial Maximum (LGM),ancient populations from different locations were redistributed throughout the region (Sikora et al.,2019;Yu et al.,2020;Kílínc et al.,2021;Mao et al.,2021).It is suggested that the emergence of many diverse ethnolinguistic groups. 展开更多
关键词 INSIGHT PHYLOGENY
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