期刊文献+
共找到3,286篇文章
< 1 2 165 >
每页显示 20 50 100
The phytohormone jasmonic acid is involved in rice resistance to Southern rice black-streaked dwarf virus 被引量:1
1
作者 Chaorui Huang Qing Liu +7 位作者 Qingling Qi Chenfei Gao Lulu Li Yanjun Li Jianping Chen Zongtao Sun Jianlong Xu Hehong Zhang 《The Crop Journal》 2025年第1期23-30,共8页
Viruses are significant pathogens causing severe plant infections and crop losses globally.The resistance mechanisms of rice to viral diseases,particularly Southern rice black-streaked dwarf virus(SRBSDV),remain poorl... Viruses are significant pathogens causing severe plant infections and crop losses globally.The resistance mechanisms of rice to viral diseases,particularly Southern rice black-streaked dwarf virus(SRBSDV),remain poorly understood.In this study,we assessed SRBSDV susceptibility in 20 Xian/indica(XI)and 20 Geng/japonica(GJ)rice varieties.XI-1B accessions in the Xian subgroup displayed higher resistance than GJ accessions.Comparative transcriptome analysis revealed changes in processes like oxidoreductase activity,jasmonic acid(JA)metabolism,and stress response.JA sensitivity assays further linked antiviral defense to the JA pathway.These findings highlight a JA-mediated resistance mechanism in rice and offer insights for breeding SRBSDV-resistant varieties. 展开更多
关键词 Oryza sativa(rice) Jasmonic acid Southern rice black-streaked dwarf virus(SRBSDV) Variety resistance Defense response
在线阅读 下载PDF
Natural variation of ClCCT promoter promotes flowering and dwarfing in adlay(Coix lacryma-jobi L.)
2
作者 Jieliang Bao Yanan Wang +11 位作者 Kuoshu Cui Xiangdong Li Hong Pan Chaoyuan Shi Xiang Yan Jinglin Wang Xiaotong Wang Qing Dou Xiaolong Dong Yibing Yuan Shufeng Zhou Chao Guo 《The Crop Journal》 2025年第3期942-951,共10页
The flowering time is a key trait that determines adaptation,yield and quality of crops.Adlay,a traditional cereal crop,has developed a distinctive agricultural industry in Southwest China and Southeast Asian countrie... The flowering time is a key trait that determines adaptation,yield and quality of crops.Adlay,a traditional cereal crop,has developed a distinctive agricultural industry in Southwest China and Southeast Asian countries.However,the currently planted varieties are all semi-domesticated landraces with delayed flowering and excessive height.These defects limit yield improvement per unit area and mechanized harvesting.In this study,a major QTL associated with flowering time and plant height in adlay has been mapped and identified as Cl CCT,a gene having a conserved function and regulatory pathway for inhibiting flowering time and increasing plant height in gramineous crops.Among the six identified haplotypes of Cl CCT,the haplotype with 38-bp insertion in promoter region of Cl CCT has earlier flowering time and wider geographical distribution than other haplotypes.The insertion variation,which arises from the segmental duplication of Cl CCT,can inhibit the expression level of reporter gene and has been used in breeding for early maturity and dwarfing.These research results not only reinforce our understanding of the importance of CCT domain protein in the tropical crops adapting to high-latitude environment,but also provide a validated breeding target for the early maturity and dwarfing of adlay. 展开更多
关键词 Early maturity dwarfING CCT domain Convergent selection Genome duplication event
在线阅读 下载PDF
Enhanced Multi-Object Dwarf Mongoose Algorithm for Optimization Stochastic Data Fusion Wireless Sensor Network Deployment
3
作者 Shumin Li Qifang Luo Yongquan Zhou 《Computer Modeling in Engineering & Sciences》 2025年第2期1955-1994,共40页
Wireless sensor network deployment optimization is a classic NP-hard problem and a popular topic in academic research.However,the current research on wireless sensor network deployment problems uses overly simplistic ... Wireless sensor network deployment optimization is a classic NP-hard problem and a popular topic in academic research.However,the current research on wireless sensor network deployment problems uses overly simplistic models,and there is a significant gap between the research results and actual wireless sensor networks.Some scholars have now modeled data fusion networks to make them more suitable for practical applications.This paper will explore the deployment problem of a stochastic data fusion wireless sensor network(SDFWSN),a model that reflects the randomness of environmental monitoring and uses data fusion techniques widely used in actual sensor networks for information collection.The deployment problem of SDFWSN is modeled as a multi-objective optimization problem.The network life cycle,spatiotemporal coverage,detection rate,and false alarm rate of SDFWSN are used as optimization objectives to optimize the deployment of network nodes.This paper proposes an enhanced multi-objective mongoose optimization algorithm(EMODMOA)to solve the deployment problem of SDFWSN.First,to overcome the shortcomings of the DMOA algorithm,such as its low convergence and tendency to get stuck in a local optimum,an encircling and hunting strategy is introduced into the original algorithm to propose the EDMOA algorithm.The EDMOA algorithm is designed as the EMODMOA algorithm by selecting reference points using the K-Nearest Neighbor(KNN)algorithm.To verify the effectiveness of the proposed algorithm,the EMODMOA algorithm was tested at CEC 2020 and achieved good results.In the SDFWSN deployment problem,the algorithm was compared with the Non-dominated Sorting Genetic Algorithm II(NSGAII),Multiple Objective Particle Swarm Optimization(MOPSO),Multi-Objective Evolutionary Algorithm based on Decomposition(MOEA/D),and Multi-Objective Grey Wolf Optimizer(MOGWO).By comparing and analyzing the performance evaluation metrics and optimization results of the objective functions of the multi-objective algorithms,the algorithm outperforms the other algorithms in the SDFWSN deployment results.To better demonstrate the superiority of the algorithm,simulations of diverse test cases were also performed,and good results were obtained. 展开更多
关键词 Stochastic data fusion wireless sensor networks network deployment spatiotemporal coverage dwarf mongoose optimization algorithm multi-objective optimization
在线阅读 下载PDF
Properties of Standard,Fuzzy,and Self-interacting Dark Matter Haloes in Dwarf Galaxies
4
作者 Fahmi M.Al Farisy Hesti R.T.Wulandari Azriel J.Dante 《Research in Astronomy and Astrophysics》 2025年第4期194-208,共15页
This study examines the properties of standard cold dark matter(CDM),fuzzy dark matter(FDM),and selfinteracting dark matter(SIDM)haloes by analyzing the rotation curves of selected dwarf galaxies from SPARC and LITTLE... This study examines the properties of standard cold dark matter(CDM),fuzzy dark matter(FDM),and selfinteracting dark matter(SIDM)haloes by analyzing the rotation curves of selected dwarf galaxies from SPARC and LITTLE THINGS in 3D catalogs.Utilizing the Markov Chain Monte Carlo(MCMC)method for model fitting and Bayesian Information Criterion for model comparison,we find that compared to CDM,both FDM and SIDM haloes generally provide better fits to the observed rotation curves.Our findings reveal that the concentration–mass relation derived from the dark matter-only simulations is not followed by concentrations or masses obtained from the rotation curve data.Our analysis highlights a positive correlation between the core sizes of FDM and SIDM haloes and the effective radius of the galaxy,attributable to gravitational couplings between baryonic and dark matter components.Moreover,our exploration of dark matter fractions at characteristic radii indicates considerable diversity in dark matter distributions across dwarf galaxies.Notably,FDM and SIDM exhibit greater diversity than CDM in this respect. 展开更多
关键词 galaxies:dwarf galaxies:kinematics and dynamics galaxies:haloes (cosmology:)dark matter
在线阅读 下载PDF
Producing Type Ia Supernovae from Hybrid CONe White Dwarfs with Mainsequence Binary Companions at Low Metallicity of Z=0.0001
5
作者 Boyang Guo Xiangcun Meng +2 位作者 Zhijia Tian Jingxiao Luo Zhengwei Liu 《Research in Astronomy and Astrophysics》 2025年第1期344-356,共13页
The nature of progenitors of Type Ia supernovae(SNe Ia)and their explosion mechanism remains unclear.It has been suggested that SNe Ia may have resulted from thermonuclear explosions of hybrid carbon-oxygen-neon white... The nature of progenitors of Type Ia supernovae(SNe Ia)and their explosion mechanism remains unclear.It has been suggested that SNe Ia may have resulted from thermonuclear explosions of hybrid carbon-oxygen-neon white dwarfs(CONe WDs)when they grow in mass to approach the Chandrasekhar mass limit by accreting matter from a binary main-sequence(MS)companion.In this work,we combine the results of detailed binary evolution calculations with population synthesis models to investigate the rates and delay times of SNe Ia in the CONe WD+MS channel at a low metallicity environment of Z=0.0001.For a constant star formation rate of 5M_(⊙)yr^(−1),our calculations predict that the SN Ia rates in the CONe WD+MS channel at low metallicity of Z=0.0001 is about 0.11−3.89×10^(−4) yr^(−1).In addition,delay times in this channel cover a wide range of 0.05−2.5 Gyr.We further compare our results to those given by a previous study for the CONe WD+MS channel with a higher metallicity of Z=0.02 to explore the influence of metallicity on the results.We find that these two metallicity environments give a slight difference in rates and delay times of SNe Ia from the CONe WD+MS channel,although SNe Ia produced at a low metallicity environment of Z=0.0001 have relatively longer delay times. 展开更多
关键词 methods numerical-(stars:)binaries(including multiple) close-stars evolution-(stars:)supernovae general-(stars:)white dwarfs
在线阅读 下载PDF
Dwarf尺寸的进一步缩减 被引量:1
6
作者 向隆刚 龚健雅 《计算机科学》 CSCD 北大核心 2007年第7期103-105,170,共4页
Dwarf不仅降低了数据立方的存储开销,而且具有结构简单、易于实现、查询和维护等优点,是一种比较理想的数据立方组织方法。为了进一步缩减Dwarf的存储尺寸,本文通过研究Dwarf结构,分别提出了浓缩Dwarf和冰山Dwarf:前者从Dwarf结构中删... Dwarf不仅降低了数据立方的存储开销,而且具有结构简单、易于实现、查询和维护等优点,是一种比较理想的数据立方组织方法。为了进一步缩减Dwarf的存储尺寸,本文通过研究Dwarf结构,分别提出了浓缩Dwarf和冰山Dwarf:前者从Dwarf结构中删除了对于查询来说冗余的内容,而后者从Dwarf结构中去掉了对于用户来说琐碎的内容。实验和分析表明,浓缩Dwarf有效地减小了Dwarf的存储尺寸,而冰山Dwarf适合于忽略细节的应用场合,极大地降低了Dwarf的存储开销。 展开更多
关键词 数据立方 dwarf 浓缩dwarf 冰山dwarf
在线阅读 下载PDF
Improved Dwarf Mongoose Optimization Algorithm for Feature Selection:Application in Software Fault Prediction Datasets 被引量:1
7
作者 Abdelaziz I.Hammouri Mohammed A.Awadallah +2 位作者 Malik Sh.Braik Mohammed Azmi Al-Betar Majdi Beseiso 《Journal of Bionic Engineering》 SCIE EI CSCD 2024年第4期2000-2033,共34页
Feature selection(FS)plays a crucial role in pre-processing machine learning datasets,as it eliminates redundant features to improve classification accuracy and reduce computational costs.This paper presents an enhanc... Feature selection(FS)plays a crucial role in pre-processing machine learning datasets,as it eliminates redundant features to improve classification accuracy and reduce computational costs.This paper presents an enhanced approach to FS for software fault prediction,specifically by enhancing the binary dwarf mongoose optimization(BDMO)algorithm with a crossover mechanism and a modified positioning updating formula.The proposed approach,termed iBDMOcr,aims to fortify exploration capability,promote population diversity,and lastly improve the wrapper-based FS process for software fault prediction tasks.iBDMOcr gained superb performance compared to other well-esteemed optimization methods across 17 benchmark datasets.It ranked first in 11 out of 17 datasets in terms of average classification accuracy.Moreover,iBDMOcr outperformed other methods in terms of average fitness values and number of selected features across all datasets.The findings demonstrate the effectiveness of iBDMOcr in addressing FS problems in software fault prediction,leading to more accurate and efficient models. 展开更多
关键词 dwarf mongoose optimization algorithm Optimization Feature selection CLASSIFICATION
在线阅读 下载PDF
Dark Matter Search in Dwarf Irregular Galaxies with Ten Years of Data from the Ice Cube Neutrino Observatory
8
作者 Yi-Fei Lü Ben-Yang Zhu +4 位作者 Rong-Lan Li Xue-Kang Guo Tian-Ci Liu Yong-Bo Huang Yun-Feng Liang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第3期75-82,共8页
Dwarf irregular galaxies(dIrrs),as rotationally supported systems,have more reliable J-factor measurements than dwarf spheroidal galaxies and have received attention as targets for dark matter detection in recent year... Dwarf irregular galaxies(dIrrs),as rotationally supported systems,have more reliable J-factor measurements than dwarf spheroidal galaxies and have received attention as targets for dark matter detection in recent years.In this paper,we use 10 yr of IceCube muon-track data and an unbinned maximum-likelihood-ratio method to search for neutrino signals beyond the background from the directions of seven dIrrs,aiming to detect neutrinos produced by heavy annihilation dark matter.We do not detect any significant signal.Based on such null results,we calculate the upper limits on the velocity-averaged annihilation cross section for 1 TeV–10 PeV dark matter.Our limits,although weaker than the strictest constraints in the literature in this mass range,are also a good complement to the existing results considering the more reliable J-factor measurements of dIrrs. 展开更多
关键词 (cosmology) dark matter-cosmology theory-galaxies dwarf
在线阅读 下载PDF
Insights into the dwarfing mechanism of pear(Pyrus betulaefolia) based on anatomical and structural analysis using X-ray scanning
9
作者 Lili Dong Chuxuan Yang +6 位作者 Jing Wang Jingjing Li Mei Zhao Dingli Li Zhiyun Qiu Chunhui Ma Zhenhua Cui 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第2期355-366,共12页
The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the p... The lack of a suitable rootstock to control scion growth has limited the development of high-density plantations in pear production, which is partly attributed to poor understanding of the dwarfing mechanism. In the present study, the rootstock of the dwarf-type pear (Pyrus betulaefolia)PY-9’ was identified and used as the material for anatomical analysis.PY-9’ grew to half the tree height of the normal cultivar Zhengdu’, along with fewer internodes and shorter length. Significant differences in growth rate betweenPY-9’ andZhengdu’ were detected at approximately 30 days after full bloom, which corresponded with the time of the greatest difference in water potential between the dwarf and normal cultivar.PY-9’ showed a higher photosynthetic rate thanZhengdu’. Anatomical analysis showed thatPY-9’ had higher area ratios of both phloem and xylem and more developed vascular tissues thanZhengdu’. The three-dimensional reconstructed skeleton of the xylem from X-ray computed tomography scanning revealed greater intervessel connectivity inZhengdu’ than inPY-9’, which could contribute to the more vigorous growth ofZhengdu’. This study thus provides the first comparison of the microstructural properties of xylem elements between a dwarfing-type and vigorous-type pear rootstock, providing new insights into the dwarfing mechanism in pear and facilitating breeding of dwarf pear rootstocks to increase crop productivity. 展开更多
关键词 Pyrus betulaefolia Anatomical analysis dwarfing mechanism Intervessel connectivity ROOTSTOCK
在线阅读 下载PDF
Investigating the Genetic Bases of Growth Regulation by E2F3 in Dwarf Surf Clams Mulinia lateralis
10
作者 YAO Ruixing WANG Chen +3 位作者 KONG Lingling WANG Yujue BAO Zhenmin HU Xiaoli 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第5期1347-1358,共12页
Bivalve aquaculture plays a crucial role in the aquaculture industry due to the economic value of many bivalve species.Understanding the underlying genetic basis of bivalve growth regulation is essential for enhancing... Bivalve aquaculture plays a crucial role in the aquaculture industry due to the economic value of many bivalve species.Understanding the underlying genetic basis of bivalve growth regulation is essential for enhancing germplasm innovation and ensuring sustainable development of the industry.Though numerous candidate genes have been identified,their functional validation remains challenging.Fortunately,the dwarf surf clam(Mulinia lateralis)serves as a promising model organism for investigating genetic mechanisms underlying growth regulation in bivalves.The GWAS study in the Yesso scallop(Patinopecten yessoensis)has pinpointed the E2F3 gene as a key regulator of growth-related traits.However,the specific role of E2F3 in bivalve growth remains unclear.This study aimed to further confirm the regulatory function of the E2F3 gene in the dwarf surf clam through RNA interference experiments.Our results revealed several genes are associated with individual growth and development,including CTS7,HSP70B2,and PGLYRP3,as well as genes involved in lipid metabolism such as FABP2 and FASN.Functional enrichment analysis indicated that E2F3 primarily modulates critical processes like amino acid and lipid metabolism.These findings suggest that E2F3 likely regulates growth in the dwarf surf clam by influencing amino acid and lipid metabolism.Overall,this study advances our understanding on the function of E2F3 gene in growth regulation in bivalves,providing valuable insights for future research in this field. 展开更多
关键词 growth regulation E2F3 RNA interference experiment transcriptomic analysis dwarf surf clam Mulinia lateralis BIVALVE
在线阅读 下载PDF
Salp Swarm Incorporated Adaptive Dwarf Mongoose Optimizer with Lévy Flight and Gbest-Guided Strategy
11
作者 Gang Hu Yuxuan Guo Guanglei Sheng 《Journal of Bionic Engineering》 SCIE EI CSCD 2024年第4期2110-2144,共35页
In response to the shortcomings of Dwarf Mongoose Optimization(DMO)algorithm,such as insufficient exploitation capability and slow convergence speed,this paper proposes a multi-strategy enhanced DMO,referred to as GLS... In response to the shortcomings of Dwarf Mongoose Optimization(DMO)algorithm,such as insufficient exploitation capability and slow convergence speed,this paper proposes a multi-strategy enhanced DMO,referred to as GLSDMO.Firstly,we propose an improved solution search equation that utilizes the Gbest-guided strategy with different parameters to achieve a trade-off between exploration and exploitation(EE).Secondly,the Lévy flight is introduced to increase the diversity of population distribution and avoid the algorithm getting stuck in a local optimum.In addition,in order to address the problem of low convergence efficiency of DMO,this study uses the strong nonlinear convergence factor Sigmaid function as the moving step size parameter of the mongoose during collective activities,and combines the strategy of the salp swarm leader with the mongoose for cooperative optimization,which enhances the search efficiency of agents and accelerating the convergence of the algorithm to the global optimal solution(Gbest).Subsequently,the superiority of GLSDMO is verified on CEC2017 and CEC2019,and the optimization effect of GLSDMO is analyzed in detail.The results show that GLSDMO is significantly superior to the compared algorithms in solution quality,robustness and global convergence rate on most test functions.Finally,the optimization performance of GLSDMO is verified on three classic engineering examples and one truss topology optimization example.The simulation results show that GLSDMO achieves optimal costs on these real-world engineering problems. 展开更多
关键词 dwarf mongoose optimization algorithm Gbest-guided Lévy flight Adaptive parameter Salp swarm algorithm Engineering optimization Truss topological optimization
在线阅读 下载PDF
HI in High Gas-phase Metallicity Dwarf Galaxy WISEA J230615.06+143927.9
12
作者 Yan Guo C.Sengupta +2 位作者 T.C.Scott P.Lagos Y.Luo 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第1期292-299,共8页
We present resolved Giant Metrewave Radio Telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA J230615.06+143927.9(z = 0.005)(hereafter J2306) and investigate whether it could be a Tidal Dwa... We present resolved Giant Metrewave Radio Telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA J230615.06+143927.9(z = 0.005)(hereafter J2306) and investigate whether it could be a Tidal Dwarf Galaxy(TDG) candidate. TDGs are observed to have higher metallicities than normal dwarfs. J2306 has an unusual combination of a blue g-r color of 0.23 mag, irregular optical morphology and high-metallicity(12 +log(O/H) = 8.68 ± 0.14), making it an interesting galaxy to study in more detail. We find J2306 to be an H I rich galaxy with a large extended, unperturbed rotating H I disk. Using our H I data we estimated its dynamical mass and found the galaxy to be dark matter(DM) dominated within its H I radius. The quantity of DM, inferred from its dynamical mass, appears to rule out J2306 as an evolved TDG. A wide area environment search reveals J2306 to be isolated from any larger galaxies which could have been the source of its high gas metallicity. Additionally, the H I morphology and kinematics of the galaxy show no indication of a recent merger to explain the high-metallicity.Further detailed optical spectroscopic observations of J2306 might provide an answer to how a seemingly ordinary irregular dwarf galaxy achieved such a high level of metal enrichment. 展开更多
关键词 galaxies:abundances galaxies:dwarf galaxies:irregular radio lines:galaxies radio lines:ISM
在线阅读 下载PDF
Stellar Populations of AGN-host Dwarf Galaxies Selected with Different Methods
13
作者 Xiejin Li 赵应和 Jinming Bai 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第6期52-67,共16页
In this paper we investigate the stellar populations and star formation histories of 235 active galactic nucleus(AGN)-host dwarf galaxies,consisting of four samples identified separately with different methods(i.e.,ra... In this paper we investigate the stellar populations and star formation histories of 235 active galactic nucleus(AGN)-host dwarf galaxies,consisting of four samples identified separately with different methods(i.e.,radio,X-ray,mid-IR and variability),utilizing the synthesis code STARLIGHT and spectra from the Sloan Digital Sky Survey Data Release 8.Our results show that the variability sample is the oldest,while the mid-IR sample is the youngest,for which the luminosity at 4020?is dominated(>50%)by the young population(t<10~8yr).The light-weighted mean stellar age of the whole sample is in general about 0.7 dex younger than the optical sample studied in Cai et al.We compare the population results between fitting models with and without a power-law(PL)component and find that the neglect of a PL component would lead to an under-and over-estimation by 0.2 and0.1 dex for the light-and mass-weighted mean stellar age,respectively,for our sample of dwarf galaxies,which has a mean fractional contribution of~16%from the AGN.In addition,we obtain further evidence for a possible suppression of star formation in the host galaxy by the central AGN.We also find that there exists an anticorrelation between the extinction-corrected[O III]luminosity and light-weighted mean stellar age,confirming our previous finding that there is a physical connection between AGN and star-forming activities in AGN-host dwarfs. 展开更多
关键词 galaxies:dwarf galaxies:active galaxies:stellar content
在线阅读 下载PDF
The Infiuence of Velocity-dependent Correction Factor on Proton Decay Reactions in Massive White Dwarfs
14
作者 Jing-Jing Liu Dong-Mei Liu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第3期169-179,共11页
Twenty-five typical massive white dwarfs(WDs)are selected and the proton decay reaction catalyzed by magnetic monopoles(MMs)for these WDs is discussed.A velocity-dependent correction factor strongly affects the cross-... Twenty-five typical massive white dwarfs(WDs)are selected and the proton decay reaction catalyzed by magnetic monopoles(MMs)for these WDs is discussed.A velocity-dependent correction factor strongly affects the cross-section.We find that a strong suppression controls the monopole catalysis of nucleon decay by the correction factor.The maximum number of MMs is captured and the luminosity can be 2.235×10^(21)and 1.7859×10^(32)erg s^(-1)(e.g.,for the O+Ne core mass WD J055631.17+130639.78).The luminosities of most massive WDs agree well with the observations at relatively low temperatures(e.g.,T_(6)=0.1),but can be three and two orders of magnitude higher than those of the observations for model(Ⅰ)and(Ⅱ)at relatively high temperatures(e.g.,T_(6)=10),respectively.The luminosities of model(Ⅰ)are about one order of magnitude higher than those of model(Ⅱ).Since we consider the effect of the number of MMs captured on the mass–radius relation and the suppression of the proton decay by the correction factor,the study by model(Ⅱ)may be an improved estimation. 展开更多
关键词 astroparticle physics-nuclear reactions-nucleosynthesis-abundances-(stars) white dwarfs
在线阅读 下载PDF
Investigation of WZ Sge-type Dwarf Nova ASASSN-19oc:Optical Spectroscopy and Multicolor Light Curve Analysis
15
作者 Viktoriia Krushevska Sergey Shugarov +3 位作者 Paolo Ochner Yuliana Kuznyetsova Mykola Petrov Peter Kroll 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第8期20-31,共12页
In this study,we present an investigation of the newly discovered dwarf nova ASASSN-19oc during its superoutburst on 2019 June 2.We carried out detailed UBVRcIc-photometric observations and also obtained a spectrum on... In this study,we present an investigation of the newly discovered dwarf nova ASASSN-19oc during its superoutburst on 2019 June 2.We carried out detailed UBVRcIc-photometric observations and also obtained a spectrum on day 7 of the outburst,which shows the presence of hydrogen absorption lines commonly found in dwarf nova outbursts.Analysis of photometric data reveals the occurrence of early superhumps in the initial days of observations,followed by ordinary and late superhumps.We have accurately calculated the period of the ordinary superhumps as Pord=0.05681(10)days and determined the periods at different stages,as well as the rate of change of the superhump period(P_(dot)=(5)P/P=8.1×10^(-5)).Additionally,we have derived the mass ratio of the components(q=0.09),and estimated the color temperature during the outburst as~11,000 K,the distance to the system(d=560 pc)and absolute magnitude of the system in outburst(MV=5.3).We have shown that outbursts of this star are very rare:based on brightness measurements on 600 archival photographic plates,we found only one outburst that occurred in 1984.This fact,as well as the properties listed above,convincingly shows that the variable ASASSN-19oc is a dwarf nova of WZ Sge type. 展开更多
关键词 (stars)binaries(including multiple) close-(stars)novae-cataclysmic variables-stars dwarf novae
在线阅读 下载PDF
Proton Decay Reaction in Massive White Dwarfs
16
作者 Jingjing Liu Dongmei Liu Qiuhe Peng 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1380-1387,共8页
Two magnetic monopole models (i.e., model (I, II)) are presented to discuss the energy resources problem based on magnetic monopole catalytic nuclear decay in massive white dwarfs. We find that the luminosities for mo... Two magnetic monopole models (i.e., model (I, II)) are presented to discuss the energy resources problem based on magnetic monopole catalytic nuclear decay in massive white dwarfs. We find that the luminosities for most of massive white dwarfs increase as the temperature increases. The luminosities of model (II) are agreed well with those of the observations at relativistic high temperature (e.g., T6=1,10), However, the luminosities of the observations can be five orders of magnitude larger than those of model (I). 展开更多
关键词 White dwarfs The Energy Source Magnetic Monopoles
在线阅读 下载PDF
水稻矮化并花发育异常突变体dwarf and deformed flower 2(ddf2)的基因定位与候选基因分析 被引量:8
17
作者 张玲 郭爽 +5 位作者 汪玲 张天泉 庄慧 龙珏臣 何光华 李云峰 《中国农业科学》 CAS CSCD 北大核心 2015年第10期1873-1881,共9页
【目的】对一个同时导致营养和生殖器官发育异常的水稻突变体进行表型鉴定、基因定位和候选基因分析,为下一步的基因克隆与功能分析奠定基础。【方法】在水稻籼型恢复系602组织培养后代中,发现一个矮化并花发育异常突变体dwarf and defo... 【目的】对一个同时导致营养和生殖器官发育异常的水稻突变体进行表型鉴定、基因定位和候选基因分析,为下一步的基因克隆与功能分析奠定基础。【方法】在水稻籼型恢复系602组织培养后代中,发现一个矮化并花发育异常突变体dwarf and deformed flower 2(ddf2)。抽穗期,以野生型为对照,对ddf2株高、主穗长、节间和功能叶的长宽等性状进行统计分析;同时利用冷冻切片等技术对茎、叶和花器官进行详细的形态和组织学分析。分别以西农1A和中花11为母本,以DDF2/ddf2杂合株系为父本构建2个F2群体进行遗传分析和基因定位,并对候选基因进行实时荧光定量PCR(real-time PCR)分析。【结果】相较于野生型,突变体各节间的长和茎粗均极显著降低,叶片极显著变短、变窄,同时花序也极显著变短。组织细胞学分析发现,突变体大叶脉数目和相邻2个大叶脉之间的小叶脉数都没有明显的变化,但相邻2个大叶脉之间的宽度明显减小,进一步比较2个小叶脉之间的叶肉细胞,发现在突变体中细胞数目和尺寸均显著降低;突变体茎秆维管束的数目与野生型相比没有明显的变化,但统计发现2个大维管束之间基本组织细胞的数量和细胞的大小都显著小于野生型,表明ddf2突变体茎、叶细胞分裂和膨胀都受到了抑制;此外,ddf2突变体的花器官特征发育受到了严重干扰:第一轮外稃顶部弯曲、内稃不同程度退化,第三轮雄蕊器官严重退化,部分甚至转化为雌蕊状器官,另外部分ddf2小穗的护颖过度发育,转变成稃片状,一些小穗还表现分生组织确定性的丢失,发育出2个以上的小花。遗传分析表明该突变性状受1对隐性基因控制。利用中花11/ddf2的1 024株F2分离群体,最终将DDF2精细定位在第11染色体短臂近着丝粒位置处,位于insertion/deletion(in/del)标记S-11和S-14之间,遗传距离分别为0.049和0.098c M,物理距离为90.295 kb,并与标记S-24共分离。分析定位区间的基因,发现共有MSU注释基因12个,其中一个编码Sec3_C蛋白的LOC_Os11g17600内部包含共分离标记S-24,进一步对该基因进行表达分析,发现该基因在突变体的叶、茎和穗中都表现出明显的下调,初步将LOC_Os11g17600作为DDF2候选基因。【结论】DDF2是一个同时控制水稻茎/叶和花器官发育的新基因。 展开更多
关键词 水稻 矮化 花器官 dwarf and DEFORMED FLOWER 2(ddf2) 基因定位
在线阅读 下载PDF
两个新水稻 Dwarf18 基因强等位突变体的表型分析及分子鉴定 被引量:3
18
作者 侯雷 袁守江 +4 位作者 尹亮 赵金凤 万国峰 张文会 李学勇 《作物学报》 CAS CSCD 北大核心 2012年第8期1416-1424,共9页
通过EMS诱变日本晴获得了s2-9和s1-146a两个矮秆突变体,其植株矮小,成熟期株高分别为日本晴的26.3%和19.2%;苗期叶片较宽,叶色深绿;穗型仍为散穗但穗长变短,粒型未发生改变。对水稻胚乳的α-淀粉酶诱导实验表明,这2个矮秆突变体与GA的... 通过EMS诱变日本晴获得了s2-9和s1-146a两个矮秆突变体,其植株矮小,成熟期株高分别为日本晴的26.3%和19.2%;苗期叶片较宽,叶色深绿;穗型仍为散穗但穗长变短,粒型未发生改变。对水稻胚乳的α-淀粉酶诱导实验表明,这2个矮秆突变体与GA的信号传导途径无关,外源活性GA3对水稻幼苗株高的促进实验显示它们应与赤霉素的生物合成有关。利用突变体与籼稻品种Dular分别杂交构建了F2群体,精细定位表明这2个突变体的表型与水稻Dwarf18(D18)基因紧密连锁。序列分析发现这2个矮秆突变体的D18基因均发生了突变,在s2-9突变体中D18基因的内含子3'拼接点发生单碱基突变,s1-146a中D18基因编码区的单碱基突变导致提前终止密码子的出现。RT-PCR结果显示,在s1-146a中D18基因表达明显增强,但在s2-9中未检测到D18基因的表达。 展开更多
关键词 水稻 矮秆突变体 dwarf18 赤霉素 精细定位
在线阅读 下载PDF
Molecular Tagging of a New Resistance Gene to Maize Dwarf Mosaic Virus Using Microsatellite Markers 被引量:6
19
作者 吴建宇 汤继华 +1 位作者 夏宗良 陈伟程 《Acta Botanica Sinica》 CSCD 2002年第2期177-180,共4页
With joint analysis based on the parents, F 1, F 2 and backcrosses, the authors found that the resistance of the maize inbred line Huangzaosi to the maize dwarf mosaic virus strain B was conditioned by a major gene ... With joint analysis based on the parents, F 1, F 2 and backcrosses, the authors found that the resistance of the maize inbred line Huangzaosi to the maize dwarf mosaic virus strain B was conditioned by a major gene and polygene, and identified a new major gene. Bulked segregate and microsatellite analysis of a F 2 progeny from the combination of Huangzaosi×Mo17 were used to identify the resistance gene, mdm1(t), on the long arm of chromosome 6. This new resistance gene is tightly linked to and located between the microsatellite markers loci, phi077 and bnlg391. The linkage distances between phi077-mdm1(t) and mdm1(t)-bnlg391 are 4.74 centiMorgan (cM) and 6.72 cM respectively. 展开更多
关键词 MAIZE maize dwarf mosaic virus resistance gene MICROSATELLITE molecular tagging
在线阅读 下载PDF
MapReduce环境下的并行Dwarf立方构建 被引量:3
20
作者 师金钢 鲍玉斌 +1 位作者 冷芳玲 于戈 《计算机科学与探索》 CSCD 2011年第5期398-409,共12页
针对数据密集型应用,提出了一种基于MapReduce框架的并行Dwarf数据立方构建算法。算法将传统Dwarf立方等价分割为多个独立的子Dwarf立方,采用MapReduce架构,实现了Dwarf立方的并行构建、查询和更新。实验证明,并行Dwarf算法一方面结合了... 针对数据密集型应用,提出了一种基于MapReduce框架的并行Dwarf数据立方构建算法。算法将传统Dwarf立方等价分割为多个独立的子Dwarf立方,采用MapReduce架构,实现了Dwarf立方的并行构建、查询和更新。实验证明,并行Dwarf算法一方面结合了MapReduce框架的并行性和高可扩展性,另一方面结合了Dwarf立方结构的数据高压缩性及数据自索引性。并行Dwarf立方既实现了数据立方的高压缩存储,提供了快速的构造和增量更新操作,又克服了MapReduce机制没有索引的劣势,实现了数据立方上的快速查询操作。 展开更多
关键词 数据密集计算 MAPREDUCE dwarf 数据立方
在线阅读 下载PDF
上一页 1 2 165 下一页 到第
使用帮助 返回顶部