期刊文献+
共找到5,690篇文章
< 1 2 250 >
每页显示 20 50 100
Marine Cirrus Properties from Satellite Remote Sensing over the South China Sea:Spatiotemporal Variations and a Case Study
1
作者 Haorui WENG Yong HAN +2 位作者 Li DONG Qicheng ZHOU Yurong ZHANG 《Advances in Atmospheric Sciences》 2026年第1期191-212,共22页
Cirrus clouds play a crucial role in the energy balance of the Earth-atmosphere system.We investigated the spatiotemporal variations of cirrus over the South China Sea(SCS)using satellite data(MOD08,MYD08,CALIPSO)and ... Cirrus clouds play a crucial role in the energy balance of the Earth-atmosphere system.We investigated the spatiotemporal variations of cirrus over the South China Sea(SCS)using satellite data(MOD08,MYD08,CALIPSO)and reanalysis data(MERRA-2)from March 2007 to February 2015(eight years).The horizontal distribution reveals lower cirrus fraction values in the northern SCS and higher values in the southern region,with minima observed in March and April and maxima sequentially occurring in August(northern SCS,NSCS),September(middle SCS,MSCS),and December(southern SCS,SSCS).Vertically,the cirrus fraction peaks in summer and reaches its lowest levels in spring.Opaque cirrus dominates during summer in the NSCS and MSCS,comprising 53.6%and 55.9%,respectively,while the SSCS exhibits a higher frequency of opaque cirrus relative to other cloud types.Subvisible cirrus clouds have the lowest frequency year-round,whereas thin cirrus is most prominent in winter in the NSCS(46.3%)and in spring in the MSCS(45.3%).A case study from September 2021 further explores the influence of ice crystal habits on brightness temperature(BT)over the SCS.Simulations utilizing five ice crystal shapes from the ARTS DDA(Atmospheric Radiative Transfer Simulator Discrete Dipole Approximation)database and the RTTOV 12.4 radiative transfer model reveal that the 8-column-aggregate shape best represents BT in the NSCS and SSCS,while the large-block-aggregate shape performs better in the SSCS. 展开更多
关键词 CIRRUS spatiotemporal variations satellite observation radiative transfer South China Sea
在线阅读 下载PDF
Unraveling the missing heritability of amyotrophic lateral sclerosis:Should we focus more on copy number variations?
2
作者 Maria Guarnaccia Valentina La Cognata +2 位作者 Giulia Gentile Giovanna Morello Sebastiano Cavallaro 《Neural Regeneration Research》 2026年第5期1997-1998,共2页
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the progressive degeneration of upper and lower motor neurons in the brainstem and spinal cord,leading to muscle weakness,para... Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the progressive degeneration of upper and lower motor neurons in the brainstem and spinal cord,leading to muscle weakness,paralysis,and respiratory failure (Morgan and Orrell,2016). 展开更多
关键词 degeneration upper lower motor neurons unraveling neurodegenerative disorder missing heritability amyotrophic lateral sclerosis copy number variations
暂未订购
Variation in plant community functional traits is driven more by species composition than by intraspecific variation along a local elevation gradient
3
作者 Alexander NOVAKOVSKIY Yuriy DUBROVSKIY 《Journal of Mountain Science》 2025年第12期4367-4378,I0001-I0057,共69页
We analyzed changes in seven functional traits of dominant herbaceous vascular plant species in 14 plant communities across an elevation gradient at the Northern Urals:plant height(PH),leaf area(LA),leaf dry mass(LDM)... We analyzed changes in seven functional traits of dominant herbaceous vascular plant species in 14 plant communities across an elevation gradient at the Northern Urals:plant height(PH),leaf area(LA),leaf dry mass(LDM),leaf dry matter content(LDMC),specific leaf area(SLA),leaf nitrogen content(LNC)and leaf carbon content(LCC).The study plots were located at one catena with elevation range from 220 to 905 m above sea level,and covered three vegetation types:forest,open woodland and mountain tundra.The community-weighted means for PH,LA and SLA were found to decrease,while LDMC and LCC increased with elevation.This was due to an increase in the proportion of stress-tolerant plant species with small physical size and conservative strategy in the leaf economic spectrum in the most elevated mountain tundra communities.The variability of PH,LDMC,and SLA decreased with increasing elevation and deteriorating of ecological conditions,which is consistent with the stress-dominance hypothesis.The variability of the other traits did not show clear trends.Changes in species composition explained 57%-94%of the observed variability of functional traits for plant communities on the elevation gradient while intraspecific changes explained only 2%to 21%of the total variability.This provides a theoretical background for using functional traits derived from global databases and those measured in habitats with similar ecological characteristics in local-scale studies. 展开更多
关键词 Functional diversity Northern Urals Intraspecific variations Interspecific variations Mountain forests Mountain tundra
原文传递
Erratum to"GenomeSyn:a bioinformatics tool for visualizing genome synteny and structural variations"[J.Genet.Genom.(2022)49,11741176]
4
作者 Zu-Wen Zhou Zhi-Guang Yu +4 位作者 Xiao-Ming Huang Jin-Shen Liu Yi-Xiong Guo Ling-Ling Chen Jia-Ming Song 《Journal of Genetics and Genomics》 2025年第8期1068-1069,共2页
Fig.1.The GenomeSyn tool for visualizing genome synteny and characterizing structural variations.A:The first synteny visualization map showed the detailed information of two or three genomes and can display structural... Fig.1.The GenomeSyn tool for visualizing genome synteny and characterizing structural variations.A:The first synteny visualization map showed the detailed information of two or three genomes and can display structural variations and other annotation information.B:The second type of visualization map was simple and only showed the synteny relationship between the chromosomes of two or three genomes.C:Multiplatform general GenomeSyn submission page,applicable to Windows,MAC and web platforms;other analysis files can be entered in the"other"option.The publisher would like to apologise for any inconvenience caused. 展开更多
关键词 two three genomes structural variations synteny relationship genomesyn visualizing genome synteny characterizing structural variationsa genome synteny synteny visualization map
原文传递
Epigenetic variation in maize agronomical traits for breeding and trait improvement Author links open overlay panel 被引量:1
5
作者 Daolei Zhang Yujun Gan +1 位作者 Liang Le Li Pu 《Journal of Genetics and Genomics》 2025年第3期307-318,共12页
Epigenetics-mediated breeding(epibreeding)involves engineering crop traits and stress responses through the targeted manipulation of key epigenetic features to enhance agricultural productivity.While conventional bree... Epigenetics-mediated breeding(epibreeding)involves engineering crop traits and stress responses through the targeted manipulation of key epigenetic features to enhance agricultural productivity.While conventional breeding methods raise concerns about reduced genetic diversity,epibreeding propels crop improvement through epigenetic variations that regulate gene expression,ultimately impacting crop yield.Epigenetic regulation in crops encompasses various modes,including histone modification,DNA modification,RNA modification,non-coding RNA,and chromatin remodeling.This review summarizes the epigenetic mechanisms underlying major agronomic traits in maize and identifies candidate epigenetic landmarks in the maize breeding process.We propose a valuable strategy for improving maize yield through epibreeding,combining CRISPR/Cas-based epigenome editing technology and Synthetic Epigenetics(SynEpi).Finally,we discuss the challenges and opportunities associated with maize trait improvement through epibreeding. 展开更多
关键词 Epibreeding Epigenetic variation Agronomical traits Epigenome editing Synthetic epigenetics
原文传递
Role of variation coefficient of stone density in determining success of shock wave lithotripsy in urinary calculi 被引量:1
6
作者 Nadeem Iqbal Aisha Hasan +2 位作者 Sajid Iqbal Sadaf Noureen Saeed Akhter 《World Journal of Nephrology》 2025年第1期110-118,共9页
BACKGROUND Various stone factors can affect the net results of shock wave lithotripsy(SWL).Recently a new factor called variation coefficient of stone density(VCSD)is being considered to have an impact on stone free r... BACKGROUND Various stone factors can affect the net results of shock wave lithotripsy(SWL).Recently a new factor called variation coefficient of stone density(VCSD)is being considered to have an impact on stone free rates.AIM To assess the role of VCSD in determining success of SWL in urinary calculi.METHODS Charts review was utilized for collection of data variables.The patients were subjected to SWL,using an electromagnetic lithotripter.Mean stone density(MSD),stone heterogeneity index(SHI),and VCSD were calculated by generating regions of interest on computed tomography(CT)images.Role of these factors were determined by applying the relevant statistical tests for continuous and categorical variables and a P value of<0.05 was gauged to be statistically significant.RESULTS There were a total of 407 patients included in the analysis.The mean age of the subjects in this study was 38.89±14.61 years.In total,165 out of the 407 patients could not achieve stone free status.The successful group had a significantly lower stone volume as compared to the unsuccessful group(P<0.0001).Skin to stone distance was not dissimilar among the two groups(P=0.47).MSD was significantly lower in the successful group(P<0.0001).SHI and VCSD were both significantly higher in the successful group(P<0.0001).CONCLUSION VCSD,a useful CT based parameter,can be utilized to gauge stone fragility and hence the prediction of SWL outcomes. 展开更多
关键词 Computed tomography Shock wave lithotripsy Stone heterogeneity variation coefficient of stone density Kidney stones
暂未订购
Anthropogenic sources and air mass transport affect spatial and seasonal variations of ambient halocarbons in southeastern China 被引量:1
7
作者 Zhaoyang Wu Zhiwei Cao +4 位作者 Xinyi Huang Yonglong Lu Pei Wang Zian Liang Xupeng An 《Journal of Environmental Sciences》 2025年第6期340-352,共13页
Halocarbons play a vital role in ozone depletion and global warming,and are regulated by the Montreal Protocol(MP)and its amendments.China has been identified as an important contributor to the halocarbon emissions,bu... Halocarbons play a vital role in ozone depletion and global warming,and are regulated by the Montreal Protocol(MP)and its amendments.China has been identified as an important contributor to the halocarbon emissions,but the regional sources of halocarbons in China are not yet well comprehended.To investigate the characteristics,emissions,and source profiles,this study conducted a field campaign in Xiamen,a coastal city in southeastern China.Higher enhancements were found in the unregulated halocarbons(CH_(3)Cl,CH_(2)Cl_(2),CHCl_(3))than in the MP eliminated species(CCl_(4),CH_(3)Br)and theMP controlled species(HCFCs,HFCs).Many of the measured halocarbons varied seasonally and regionally,depending on the anthropogenic sources and atmospheric transport.Backward trajectory analysis showed that the air masses from inland were polluted over Shandong,Hebei,and northern Fujian in the cold season,while the air masses fromthe sea in the warm season were clean.Different air masses in two seasons were associated with the halocarbon patterns in the study area.Industrial activities,especially solvent usage,were the primary sources of halocarbons.The emission hot spots in Fujian Province were concentrated in Sanming,Fuzhou,and Xiamen,and the unregulated halocarbons made the largest contribution.This study provides an insight for a deep understanding of the characteristics and potential sources of halocarbons,and for strengthened management of halocarbons in China. 展开更多
关键词 HALOCARBONS Source apportionment Southeastern China Seasonal variations Montreal Protocol
原文传递
Single-nucleotide polymorphisms and copy number variations drive adaptive evolution to freezing stress in a subtropical evergreen broadleaved tree:Hexaploid wild Camellia oleifera 被引量:1
8
作者 Haoxing Xie Kaifeng Xing +3 位作者 Jun Zhou Yao Zhao Jian Zhang Jun Rong 《Plant Diversity》 2025年第2期214-228,共15页
Subtropical evergreen broad-leaved trees are usually vulnerable to freezing stress,while hexaploid wild Camellia oleifera shows strong freezing tolerance.As a valuable genetic resource of woody oil crop C.oleifera,wil... Subtropical evergreen broad-leaved trees are usually vulnerable to freezing stress,while hexaploid wild Camellia oleifera shows strong freezing tolerance.As a valuable genetic resource of woody oil crop C.oleifera,wild C.oleifera can serve as a case for studying the molecular bases of adaptive evolution to freezing stress.Here,47 wild C.oleifera from 11 natural distribution sites in China and 4 relative species of C.oleifera were selected for genome sequencing.“Min Temperature of Coldest Month”(BIO6)had the highest comprehensive contribution to wild C.oleifera distribution.The population genetic structure of wild C.oleifera could be divided into two groups:in cold winter(BIO6≤0℃)and warm winter(BIO6>0℃)areas.Wild C.oleifera in cold winter areas might have experienced stronger selection pressures and population bottlenecks with lower N_(e) than those in warm winter areas.155 singlenucleotide polymorphisms(SNPs)were significantly correlated with the key bioclimatic variables(106 SNPs significantly correlated with BIO6).Twenty key SNPs and 15 key copy number variation regions(CNVRs)were found with genotype differentiation>50%between the two groups of wild C.oleifera.Key SNPs in cis-regulatory elements might affect the expression of key genes associated with freezing tolerance,and they were also found within a CNVR suggesting interactions between them.Some key CNVRs in the exon regions were closely related to the differentially expressed genes under freezing stress.The findings suggest that rich SNPs and CNVRs in polyploid trees may contribute to the adaptive evolution to freezing stress. 展开更多
关键词 Adaptive evolution Camellia oleifera Copy number variations Freezing stress POLYPLOID Single-nucleotide polymorphisms
在线阅读 下载PDF
Southerly Moisture Surges over the South China Sea in Early-Summer Season: Multiscale Variations and Impacts on Rainfall 被引量:1
9
作者 ZHA Xu-mei CHEN Gui-xing +1 位作者 LIU Bi-qi QIN Hui-ling 《Journal of Tropical Meteorology》 2025年第1期87-106,共20页
Southerly moisture surges over the central South China Sea(SCS)are characterized by the strengthening of lowlevel southerlies that transport moisture northward from the Pacific or Indian Oceans to South China.These su... Southerly moisture surges over the central South China Sea(SCS)are characterized by the strengthening of lowlevel southerlies that transport moisture northward from the Pacific or Indian Oceans to South China.These surge events typically occur for days in the early-summer season(from April to June)and can lead to heavy rains in South China.This study categorizes surge events into three types of flow patterns and examines their multiscale variations and impacts on rainfall.The first type occurs mainly in April,with the southeasterlies enhanced by a deepening trough in South China and the western Pacific subtropical high established over the SCS.The second type of surge events mostly appears in June,featuring the prevailing southwesterlies of summer monsoon from the Indian Ocean during the active phases of intraseasonal oscillations.Most surge events exhibit semi-diurnal variations with morning and afternoon peaks of northward moisture fluxes.Specifically,the first type features a dominant afternoon peak,while the second type shows a dominant early-morning peak,which is induced by thermal contrast between the Indochina Peninsula and the SCS.In general,the surge events enhance moisture convergence and increase rainfall downstream in South China,but they show some regional differences.The second type strengthens moisture convergence and rainfall in coastal regions with a morning peak.In contrast,the first type enhances inland rainfall with a morning peak,while moisture divergence dominates coastal regions.The third type of surge events denotes transitional conditions between the first two types,in terms of atmospheric circulations,diurnal cycles,and rainfall patterns.These results highlight a diversity of regional moisture surges and related rainfall ranging from diurnal to sub-seasonal scales. 展开更多
关键词 southerly moisture surges diurnal variations synoptic disturbances RAINFALL South China Sea
在线阅读 下载PDF
A Robust GNSS Navigation Filter Based on Maximum Correntropy Criterion with Variational Bayesian for Adaptivity 被引量:1
10
作者 Dah-Jing Jwo Yi Chang Ta-Shun Cho 《Computer Modeling in Engineering & Sciences》 2025年第3期2771-2789,共19页
In this paper,an advanced satellite navigation filter design,referred to as the Variational Bayesian Maximum Correntropy Extended Kalman Filter(VBMCEKF),is introduced to enhance robustness and adaptability in scenario... In this paper,an advanced satellite navigation filter design,referred to as the Variational Bayesian Maximum Correntropy Extended Kalman Filter(VBMCEKF),is introduced to enhance robustness and adaptability in scenarios with non-Gaussian noise and heavy-tailed outliers.The proposed design modifies the extended Kalman filter(EKF)for the global navigation satellite system(GNSS),integrating the maximum correntropy criterion(MCC)and the variational Bayesian(VB)method.This adaptive algorithm effectively reduces non-line-of-sight(NLOS)reception contamination and improves estimation accuracy,particularly in time-varying GNSS measurements.Experimental results show that the proposed method significantly outperforms conventional approaches in estimation accuracy under heavy-tailed outliers and non-Gaussian noise.By combining MCC with VB approximation for real-time noise covariance estimation using fixed-point iteration,the VBMCEKF achieves superior filtering performance in challenging GNSS conditions.The method’s adaptability and precision make it ideal for improving satellite navigation performance in stochastic environments. 展开更多
关键词 Maximum correntropy criterion variational Bayesian extended Kalman filter GNSS
在线阅读 下载PDF
A Review on Modeling Environmental Loading Effects and Their Contributions to Nonlinear Variations of Global Navigation Satellite System Coordinate Time Series 被引量:1
11
作者 Zhao Li Weiping Jiang +3 位作者 Tonie van Dam Xiaowei Zou Qusen Chen Hua Chen 《Engineering》 2025年第4期26-37,共12页
Nonlinear variations in the coordinate time series of global navigation satellite system(GNSS) reference stations are strongly correlated with surface displacements caused by environmental loading effects,including at... Nonlinear variations in the coordinate time series of global navigation satellite system(GNSS) reference stations are strongly correlated with surface displacements caused by environmental loading effects,including atmospheric, hydrological, and nontidal ocean loading. Continuous improvements in the accuracy of surface mass loading products, performance of Earth models, and precise data-processing technologies have significantly advanced research on the effects of environmental loading on nonlinear variations in GNSS coordinate time series. However, owing to theoretical limitations, the lack of high spatiotemporal resolution surface mass observations, and the coupling of GNSS technology-related systematic errors, environmental loading and nonlinear GNSS reference station displacements remain inconsistent. The applicability and capability of these loading products across different regions also require further evaluation. This paper outlines methods for modeling environmental loading, surface mass loading products, and service organizations. In addition, it summarizes recent advances in applying environmental loading to address nonlinear variations in global and regional GNSS coordinate time series. Moreover, the scientific questions of existing studies are summarized, and insights into future research directions are provided. The complex nonlinear motion of reference stations is a major factor limiting the accuracy of the current terrestrial reference frame. Further refining the environmental load modeling method, establishing a surface mass distribution model with high spatiotemporal resolution and reliability, exploring other environmental load factors such as ice sheet and artificial mass-change effects, and developing an optimal data-processing model and strategy for reprocessing global reference station data consistently could contribute to the development of a millimeter-level nonlinear motion model for GNSS reference stations with actual physical significance and provide theoretical support for establishing a terrestrial reference frame with 1 mm accuracy by 2050. 展开更多
关键词 Environmental loading Global navigation satellite system Nonlinear variations Time series analysis Surface mass distribution Green’s function Spherical harmonic function
在线阅读 下载PDF
The Minimal Affine Total Variation in Minkowski Spaces
12
作者 MOU Shuang 《数学进展》 北大核心 2025年第1期164-176,共13页
In this paper,we use the solution of the even functional Minkowski problem to show that there is a minimizing affine Minkowski total variation of the function of bounded variation.Moreover,for the Minkowski total vari... In this paper,we use the solution of the even functional Minkowski problem to show that there is a minimizing affine Minkowski total variation of the function of bounded variation.Moreover,for the Minkowski total variation,we use the method of convexation to establish the same conclusion as the convex body space. 展开更多
关键词 convex body minimal surface area Minkowski space bounded variation
原文传递
Convergence of a New Bregman Projection Method with a Self-adaptive Stepsize for Solving Monotone Inclusion Problems and Variational Inequality Problems in Reflexive Banach Spaces
13
作者 CHEN Lulu CAI Gang 《数学进展》 北大核心 2025年第1期141-163,共23页
The purpose of this article is to introduce a new method with a self-adaptive stepsize for approximating a common solution of monotone inclusion problems and variational inequality problems in reflexive Banach spaces.... The purpose of this article is to introduce a new method with a self-adaptive stepsize for approximating a common solution of monotone inclusion problems and variational inequality problems in reflexive Banach spaces.The strong convergence result for our method is established under some standard assumptions without any requirement of the knowledge of the Lipschitz constant of the mapping.Several numerical experiments are provided to verify the advantages and efficiency of proposed algorithms. 展开更多
关键词 Bregman distance variational inequality monotone inclusion maximal operator reflexive Banach space
原文传递
Genetic variations of wood properties and growth characters of Ko-rean pines from different provenances 被引量:5
14
作者 王慧梅 夏德安 +1 位作者 王文杰 杨书文 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第4期277-280,337,共4页
Totally 26 provenance stands of 17-year-old Korean pine were selected for investigating wood properties and growth characters in Mao抏rshan Experimental Forest Farm of Northeast Forestry University in 1999. The anatom... Totally 26 provenance stands of 17-year-old Korean pine were selected for investigating wood properties and growth characters in Mao抏rshan Experimental Forest Farm of Northeast Forestry University in 1999. The anatomical property indexes, including tracheid length, tracheid diameter and wall-indiameter ratio, and the physical property indexes, such as growth ring width, late wood percentage and growth ring density, were measured for wood properties. Growth character indexes, including tree height and diameter at breast height, were also measured. The analytical results showed that there exited obviously dif-ference in wood property indexes between different provenances, which is suggested that wood properties are controlled by their genetic differences. The growth character indexes of Korean pines presented significant difference and they might also be controlled by their genetic differences. Most parameters of wood properties mainly varied in the direction of longitude, but the parameters of growth characters varied in the direction of latitude. 展开更多
关键词 Korean pine Provenance trial Wood properties Geographical variation Genetic variation
在线阅读 下载PDF
Geometric Morphometric Analysis of Body Shape Variation in Glossogobius giuris from Lake Mainit,Agusan del Norte,Philippines
15
作者 Cresencio C.Cabuga,Jr. Ana Marie D.Empeño Jojean Marie D.Pondang 《Research in Ecology》 2025年第2期144-158,共15页
Most fish exhibit remarkable morphological diversity,which is often influenced by genetic variation and ecological pressures.Consequently,these are the outcomes of organisms’responses to their environment.Meanwhile,m... Most fish exhibit remarkable morphological diversity,which is often influenced by genetic variation and ecological pressures.Consequently,these are the outcomes of organisms’responses to their environment.Meanwhile,modern morphometrics can quantify shape variation within species of the same group.This study aims to determine the body shape variation of Glossogobius giuris from Lake Mainit,Agusan Del Norte,Philippines.60 adult,uniform-sized fish samples were collected and subjected to standardized laboratory procedures.Further,the samples were digitized for 16 homologous landmark points and loaded into Symmetry Asymmetry Geometric Data(SAGE)Software.Across the tested factors—individuals,sides,and individual x sides—result shows that shape variations among individuals were highly significant(F=2.1045,p<0.0001),along with among males(F=3.2711,p<0.0001).Females exhibited higher Fluctuating Asymmetry(FA)(F=18.99,p<0.0001)compared to males(F=7.0964,p<0.0001).It suggests morphological shape differences across the sexes,and the shape variation observed could be a response to environmental perturbations.Shape variations were associated with swimming,food hunting,and predator defense.Moreover,Principal Component Analysis(PCA)demonstrates higher scores of FA in females(81.96%)than in males(74.76%).It was noticed that females had a high fluctuating asymmetry.It might be due to various physiological and ecological pressures compared to males.The observed levels of directional and fluctuating asymmetry in males and females,respectively,may indicate sex-linked morphological and developmental processes,which are important to consider in ecological or evolutionary contexts.Thus,utilizing geometric morphometrics can depict subtle differences across the same populations. 展开更多
关键词 Caraga Region Ecology Freshwater Fish Landmarks LIMNOLOGY PHENOTYPES Shape variation
在线阅读 下载PDF
Unraveling the evolutionary complexity of Lycoris:Insights into chromosomal variation,genome size,and phylogenetic relationships
16
作者 Xiaochun Shu Ruisen Lu +5 位作者 Pat Heslop-Harrison Trude Schwarzacher Zhong Wang Yalong Qin Ning Wang Fengjiao Zhang 《Plant Diversity》 2025年第6期931-943,共13页
Hybridization and polyploidy are key drivers of species diversity and genome variation in Lycoris,but their cytological and evolutionary consequences remain poorly understood.Here,we investigated chromosome numbers an... Hybridization and polyploidy are key drivers of species diversity and genome variation in Lycoris,but their cytological and evolutionary consequences remain poorly understood.Here,we investigated chromosome numbers and genome sizes in 64 accessions representing the morphological diversity across the genus.Chromosome numbers ranged from 12 to 33,with seven accessions newly identified,including L.chunxiaoensis(2n=33),two putative L.guangxiensis(2n=19),and fivenatural hybrids(2n=16,18,29,33).Genome sizes varied from 18.03 Gb(L.wulingensis)to 32.62 Gb(L.caldwellii).Although no significantcorrelationwas found between genome size and chromosome number across all accessions,a strong correlation within ploidy-level groups(i.e.,diploid or aneuploid)suggested roles for post-polyploid diploidization,aneuploidy,and dysploidy in speciation.Phylogenetic analyses based on chloroplast genomes and nuclear DNA sequences revealed significantdiscordance,indicating a complex reticulate evolution and historical hybridization,which may complicate morphological classification.Chromosome number aligned more closely with morphological groups,underscoring the necessity of integrating cytological,molecular,and morphological data for accurate taxonomy,particularly in largegenome taxa.Based on this evidence,we propose a putative speciation pathway involving multiple hybridization and polyploidization events,with allopolyploidy playing a predominant role.Furthermore,our results indicate that the species L.insularis and L.longifolia are geographic populations of L.sprengeri and L.aurea,respectively,and confirmedthe distribution of L.traubii and L.albiflora in China' Mainland.These findingsoffer new insights into the mechanisms underlying speciation,interspecificrelationships,and the evolutionary history of Lycoris. 展开更多
关键词 LYCORIS Chromosome variation Genome size HYBRIDIZATION POLYPLOIDY PHYLOGENETICS
在线阅读 下载PDF
An assessment of atmospheric concentrations and spatiotemporal variation of BTEX and associated pollutants in India
17
作者 Sruthi Jayaraj S.M.Shiva Nagendra 《Journal of Environmental Sciences》 2025年第4期230-245,共16页
Benzene,toluene,ethylbenzene,and xylene(BTEX)pollution poses a serious threat to public health and the environment because of its respiratory and neurological effects,carcinogenic properties,and adverse effects on air... Benzene,toluene,ethylbenzene,and xylene(BTEX)pollution poses a serious threat to public health and the environment because of its respiratory and neurological effects,carcinogenic properties,and adverse effects on air quality.BTEX exposure is a matter of grave concern in India owing to the growing vehicular and development activities,necessitating the assessment of atmospheric concentrations and their spatial variation.This paper presents a comprehensive assessment of ambient concentrations and spatiotemporal variations of BTEX in India.The study investigates the correlation of BTEX with other criteria pollutants andmeteorological parameters,aiming to identify interrelationships and diagnostic indicators for the source characterization of BTEX emissions.Additionally,the paper categorizes various regions in India according to the Air Quality Index(AQI)based on BTEX pollution levels.The results reveal that the northern zone of India exhibits the highest levels of BTEX pollution compared to central,eastern,and western regions.In contrast,the southern zone experiences the least pollution with BTEX.Seasonal analysis indicates that winter and postmonsoon periods,characterized by lower temperatures,are associated with higher BTEX levels due to the accumulation of localized emissions.When comparing the different zones in India,high traffic emissions and localized activities,such as solvent use and solvent evaporation,are found to be the primary sources of BTEX.The findings of the current study aid in source characterization and identification,and better understanding of the region’s air quality problems,which helps in the development of focused BTEX pollution reduction and control strategies. 展开更多
关键词 VOCS BTEX INDIA AQI Spatiotemporal variation
原文传递
Day-to-day variation in chlorophyll fluorescence parameters of northern and southern silver birch in a common garden
18
作者 Olusegun Olaitan Akinyemi JaroslavČepl +4 位作者 Sarita Keski-Saari Jan Stejskal Ivana Tomášková Markku Keinänen Sari Kontunen-Soppela 《Journal of Forestry Research》 2025年第2期108-120,共13页
We used fast chlorophyll fluorescence transients(OJIP) to study provenance-related differences in photosynthetic performance and the magnitude of day-to-day chlorophyll fluorescence(ChlF) variation in northern(67°... We used fast chlorophyll fluorescence transients(OJIP) to study provenance-related differences in photosynthetic performance and the magnitude of day-to-day chlorophyll fluorescence(ChlF) variation in northern(67°N)and southern(62°N) silver birches in a common garden at62°N.ChlF transients were measured five times during two weeks in the middle of summer to avoid seasonal variation.Differences in growth and leaf morphological traits between the provenances were also examined.The northern trees had higher chlorophyll content,larger leaf areas,and higher leaf fresh and dry mass than the southern trees,but the leaf mass per area did not differ between the provenances.The southern trees were taller and showed higher annual shoot growth than the northern trees.For all the ChlF parameters,day-to-day variation was significant and followed the same pattern for both provenances with no significant provenance ×day interaction,suggesting a similar response to environmental variation.The northern provenance had higher values in parameters related to the reduction of end electron acceptors at the Photosystem I(PSI) acceptor side as probed by ChlF.This and higher values for performance indices PI_(abs) and PI_(tot) in northern than in southern trees suggest higher photosynthetic performance of northern trees in line with the latitudinal compensation strategy.Provenance differences in these parameters increased towards the end of the measurement period,suggesting preparation for earlier growth cessation in northern trees triggered by the shortening day length.The study shows that provenance differences in ChlF can be relatively stable regardless of environmental variation but might be influenced by physiological alterations in preparation for future changes in environmental conditions. 展开更多
关键词 JIP test Betula pendula PROVENANCES Intra-annual variation CHLOROPHYLL Leaf mass per area LMA Growth
在线阅读 下载PDF
Variation and Reconstruction of Zhuge Liang’s Images in Three Kingdoms Translated by Moss Roberts
19
作者 YI Zi-ning 《Journal of Literature and Art Studies》 2025年第5期366-374,共9页
As a classic novel,San Guo Yan Yi raises a crucial cross-cultural communication question:how can Western readers accurately and objectively understand Zhuge Liang’s image in its overseas translation?Influenced by cul... As a classic novel,San Guo Yan Yi raises a crucial cross-cultural communication question:how can Western readers accurately and objectively understand Zhuge Liang’s image in its overseas translation?Influenced by cultural context disparities and the intervention of the translator’s subjectivity,Moss Roberts has boldly transformed and reshaped Zhuge Liang’s traditionally-perceived image.In Three Kingdoms,from the image of an omnipotent wise man,a benevolent person,and a loyal and unwavering sage,Moss Roberts constructs images of Zhuge Liang who,while possessing genuine talent and knowledge,is also narrow-minded,jealous of the able and virtuous,and has a tinge of hypocrisy,thus creating a strong tragic implication.Through comparisons,this study aims to provide a new dimension for Zhuge Liang’s image,offering references for the study of cross-cultural translation of Chinese classical literature,deepening the understanding of how cultural identities are negotiated in translation. 展开更多
关键词 Three Kingdoms Moss Roberts Zhuge Liang variation RECONSTRUCTION
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部