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Determining Cotton Fiber Gene Function via Structuring of Mutant Populations for High-Throughput Reverse Genetics
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作者 Thea A.WILKINS Dick AULD 《棉花学报》 CSCD 北大核心 2002年第S1期50-50,共1页
The NSF Cotton Genome Centers EST projecthas released】36000 cotton fiber EST sequencesfrom Gossypium arboreum,an A-genome diploidspecies.Of the approximately 10000 genesexpressed in rapidly elongating cotton fibers,5... The NSF Cotton Genome Centers EST projecthas released】36000 cotton fiber EST sequencesfrom Gossypium arboreum,an A-genome diploidspecies.Of the approximately 10000 genesexpressed in rapidly elongating cotton fibers,50% or more encode unknown gene functions.The next challenge facing cotton researchers isdetermining the function of the fiber genes,andwhat role each plays in determiningagronomically important fiber traits. 展开更多
关键词 COTTON COTTON GOSSYPIUM MUTANT Genetics Genome encode alleles PHENOTYPE populations
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Development of Permanent Mapping Populations RILs in Diploid A Genome
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作者 WAGHMARE VIJAY N DONGRE A B GOTMARE Vinita PATIL P G DESHPANDE L A KHADI B M 《棉花学报》 CSCD 北大核心 2008年第S1期99-,共1页
Recombinant inbred lines(RILs) serve as powerful tools for genetic mapping.RILs are obtained by crossing two inbred lines followed by repeated selfing or sib-mating to create a set of new
关键词 QTLS LENGTH Development of Permanent Mapping populations RILs in Diploid A Genome
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Genetic Differentiation Analyses Based on mtDNA COⅡ Gene Sequences Among Different Geographic Populations of Aphis glycines(Hemiptera: Aphididae) in Northeast China 被引量:1
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作者 Li Ran Han Lan-lan +4 位作者 Ye Le-fu Zhang Hong-yu Sun Wen-peng Tong Xin Zhao Kui-jun 《Journal of Northeast Agricultural University(English Edition)》 CAS 2015年第3期23-31,共9页
Aphis glycines (Hemiptera: Aphididae) is considered as a cosmopolitan pest of cultivated soybean, major difficulties in its control measures may be due to its higher genetic diversity; however, the knowledge about ... Aphis glycines (Hemiptera: Aphididae) is considered as a cosmopolitan pest of cultivated soybean, major difficulties in its control measures may be due to its higher genetic diversity; however, the knowledge about population genetic diversity of this species is limited. This study aimed to represent the genetic differentiation among different geographic populations of soybean aphid in Northeast China. In order to investigate and assess the genetic diversity, genetic differentiation, molecular variance, population structure, ecological importance and evolutionary history of A. glycines, we sequenced a fragment of one protein-coding gene, the cytochrome c oxidase I/of mitochondrial DNA gene. The results showed that four haplotypes were defined among CO 11 gene of 180 sequences of soybean aphid in Northeast China including H1 shared by all the populations. Lower haplotype diversity (Hd=0.3590± 0.0420) and nucleotide diversity (Pi=0.0012±0.0002) were observed and high gene flow was detected in every two populations, while most of the variation (80.81%) arose from variability within A. glycines from individuals. Low genetic differentiation and high gene flow (Nm=2.106) indicated a high migration rate between the populations, which might reveal that gene flow in different geographic populations did not affect by geographical distance. The phylogenetic tree and the haplotype network ofA. glycines were obtained based on sequences of CO Ⅱ gene, there were no significant genealogical branches or clusters recognized in NJ tree, and no clear distribution, delineation of haplotypes were demonstrated in the haplotype network according to geographical location. This study rejected the vicariance hypothesis: geographic isolation could be a barrier and it restricted A. glycines gene flow among 10 populations. 展开更多
关键词 Aphis glycines mtDNA CO geographic population gene flow genetic differentiation
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城市层级体系三要素:规模与密度的内生交互及对创新的影响
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作者 王如玉 王志高 梁琦 《中国软科学》 北大核心 2025年第9期79-90,共12页
规模、密度与创新是城市层级跃升的关键要素。现有研究往往割裂考察各个维度,缺乏整合性分析框架。在构建了一个融合规模与密度约束的空间创新理论模型的基础上,运用2010—2020年中国297个地级及以上城市面板数据进行实证检验。研究发现... 规模、密度与创新是城市层级跃升的关键要素。现有研究往往割裂考察各个维度,缺乏整合性分析框架。在构建了一个融合规模与密度约束的空间创新理论模型的基础上,运用2010—2020年中国297个地级及以上城市面板数据进行实证检验。研究发现:第一,城市规模与创新绩效呈显著正相关,但这种关系受空间密度的调节;第二,创新绩效与人口密度呈倒U型关系,存在特定的最优密度阈值;第三,最优密度阈值随城市规模增大而提高;第四,数字化促进虚拟集聚从而降低空间交流成本,有效提升最优密度阈值并放大规模与密度效应的创新溢出。计算结果表明,包括超大特大城市在内的大多数中国城市仍处于最优密度阈值以下,具有显著加密空间。研究结果揭示了城市规模、密度与创新三要素的非线性互动机制,提出空间经济学视域下的城市层级体系三要素理论,对中国城市高质量发展有启示意义。 展开更多
关键词 城市规模 空间密度 创新 虚拟集聚 最优密度阈值 空间经济学
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Seasonal population trend and relative occurrence of pests and their natural enemies among cotton species and cultivars in India 被引量:1
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作者 NAGRARE V.S. NAIKWADI Bhausaheb +4 位作者 FAND Babasaheb B. NAIK V.Chinna Babu TENGURI Prabhulinga GOKTE‑NARKHEDKAR Nandini WAGHMARE V.N. 《Journal of Cotton Research》 2025年第2期178-192,共15页
Background Cotton crop is infested by numerous arthropod pests from sowing to harvesting,causing substantial direct and indirect yield losses.Knowledge of seasonal population trends and the relative occurrence of pest... Background Cotton crop is infested by numerous arthropod pests from sowing to harvesting,causing substantial direct and indirect yield losses.Knowledge of seasonal population trends and the relative occurrence of pests and their natural enemies is required to minimize the pest population and yield losses.In the current study,analysis of the seasonal population trend of pests and natural enemies and their relative occurrence on cultivars of three cotton species in Central India has been carried out.Results A higher number and diversity of sucking pests were observed during the vegetative cotton growth stage(60 days after sowing),declining as the crop matured.With the exception of cotton jassid(Amrasca biguttula biguttula Ishida),which caused significant crop damage mainly from August to September;populations of other sucking insects seldom reached economic threshold levels(ETL)throughout the studied period.The bollworm complex populations were minimal,except for the pink bollworm(Pectinophora gossypiella Saunders),which re-emerged as a menace to cotton crops during the cotton cropping season 2017–2018 due to resistance development against Bt-cotton.A reasonably good number of predatory arthropods,including coccinellids,lacewings,and spiders,were found actively preying on the arthropod pest complex of the cotton crop during the early vegetative growth stage.Linear regression indicates a significant relationship between green boll infestations and pink bollworm moths in pheromone traps.Multiple linear regression analyse showed mean weekly weather at one-or two-week lag periods had a significant impact on sucking pest population(cotton aphid,cotton jassid,cotton whitefly,and onion thrips)fluctuation.Gossypium hirsutum cultivars RCH 2 and DCH 32,and G.barbadense cultivar Suvin were found susceptible to cotton jassid and onion thrips.Phule Dhanvantary,an G.arboreum cotton cultivar,demonstrated the highest tolerance among all evaluated cultivars against all sucking pests.Conclusion These findings have important implications for pest management in cotton crops.Susceptible cultivars warrant more attention for plant protection measures,making them more input-intensive.The choice of appropriate cultivars can help minimize input costs,thereby increasing net returns for cotton farmers. 展开更多
关键词 COTTON PESTS Population trend Relative occurrence CULTIVARS Natural enemies
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Five novel ZNF469 gene mutations in sporadic keratoconus patients in the Han Chinese population
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作者 CAO Yanna DENG Zhihong +3 位作者 HE Guiyun XIAO Li ZHANG Feng SU Feng 《中南大学学报(医学版)》 北大核心 2025年第6期931-939,共9页
Objective:Keratoconus(KC)is a progressive corneal ectasia disorder,arising from a myriad of causes including genetic predispositions,environmental factors,biomechanical influences,and inflammatory reactions.This study... Objective:Keratoconus(KC)is a progressive corneal ectasia disorder,arising from a myriad of causes including genetic predispositions,environmental factors,biomechanical influences,and inflammatory reactions.This study aims to identify potential pathogenetic gene mutations in patients with sporadic KC in the Han Chinese population.Methods:Twenty-five patients with primary KC as well as 50 unrelated population matched healthy controls,were included in this study to identify potential pathogenic gene mutations among sporadic KC patients in the Han Chinese population.Sanger sequencing and whole-exome sequencing(WES)were used to analyze mutations in the zinc finger protein 469(ZNF469)gene.Bioinformatics analysis was conducted to explore the potential role of ZNF469 in KC pathogenesis.Results:Five novel heterozygous missense variants were identified in KC patients.Among them,2 compound heterozygous variants,c.8986G>C(p.E2996Q)with c.11765A>C(p.D3922A),and c.4423C>G(p.L1475V)with c.10633G>A(p.G3545R),were determined to be possible pathogenic factors for KC.Conclusion:Mutations in the ZNF469 gene may contribute to the development of KC in the Han Chinese population.These mutation sites may provide valuable information for future genetic screening of KC patients and their families. 展开更多
关键词 KERATOCONUS ZNF469 gene MUTATION Sanger sequencing Han Chinese population
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Periodic Traveling Wave Solutions of a Single Population Model with Advection and Distributed Delay
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作者 GUO Zilin YU Tao TANG Xiaosong 《应用数学》 北大核心 2025年第4期988-995,共8页
In this paper,we investigate the periodic traveling wave solutions problem for a single population model with advection and distributed delay.By the bifurcation analysis method,we can obtain periodic traveling wave so... In this paper,we investigate the periodic traveling wave solutions problem for a single population model with advection and distributed delay.By the bifurcation analysis method,we can obtain periodic traveling wave solutions for this model under the influence of advection term and distributed delay.The obtained results indicate that weak kernel and strong kernel can both deduce the existence of periodic traveling wave solutions.Finally,we apply the main results in this paper to Logistic model and Nicholson’s blowflies model. 展开更多
关键词 Single population model Advection Distributed delay Periodic traveling wave solution
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中国转基因作物的环境安全评介与风险管理 被引量:10
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作者 吴孔明 刘海军 《华中农业大学学报》 CAS CSCD 北大核心 2014年第6期112-114,共3页
基因工程技术是21世纪最伟大的科学技术之一,基因工程技术的应用开启了一次全新的农业"绿色革命"。自1996年美国第一例商业化转基因作物诞生以来,全球转基因作物的种植快速平稳增长。转基因作物的种植具有巨大的潜在效益,但... 基因工程技术是21世纪最伟大的科学技术之一,基因工程技术的应用开启了一次全新的农业"绿色革命"。自1996年美国第一例商业化转基因作物诞生以来,全球转基因作物的种植快速平稳增长。转基因作物的种植具有巨大的潜在效益,但是其可能带来的环境风险已成为了人们关心和争论的焦点。转基因作物的安全性已然成为许多国家和政府不得不面对的主要议题之一。在过去的20年里。 展开更多
关键词 基因工程技术 环境风险 潜在效益 cotton PAPAYA 环境安全性 生产性试验 CROPS creased populations
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QTL mapping associated with Verticillium wilt resistance in cotton based on MAGIC population
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作者 AYYAZ Muhammad CHANG Zewei +9 位作者 DING Shugen HAN Peng XU Lin ABUDUKEYOUMU Abudurezike SIDDHO Irfan Ali LI Zhibo LIN Hairong XU Jianwei WU Yuanlong NIE Xinhui 《Journal of Cotton Research》 2025年第1期61-75,共15页
Background Cotton is an important cash crop in China and a key component of the global textile market.Verticil-lium wilt is a major factor affecting cotton yield.Single nucleotide polymorphism(SNP)markers and phenotyp... Background Cotton is an important cash crop in China and a key component of the global textile market.Verticil-lium wilt is a major factor affecting cotton yield.Single nucleotide polymorphism(SNP)markers and phenotypic data can be used to identify genetic markers and loci associated with cotton resistance to Verticillium wilt.We used eight upland cotton parent materials in this study to construct a multiparent advanced generation inter-cross(MAGIC)population comprising 320 lines.The Verticillium wilt resistance of the MAGIC population was identified in the green-house in 2019,and the average relative disease index(ARDI)was calculated.A genome-wide association study(GWAS)was performed to discover SNP markers/genes associated with Verticillium wilt resistance.Results ARDI of the MAGIC population showed wide variation,ranging from 16.7 to 79.4 across three replicates.This variation reflected a diverse range of resistance to Verticillium wilt within the population.Analysis of distribution pat-terns across the environments revealed consistent trends,with coefficients of variation between 12.25%and 21.96%.Families with higher ARDI values,indicating stronger resistance,were more common,likely due to genetic diver-sity and environmental factors.Population structure analysis divided the MAGIC population into three subgroups,with Group I showing higher genetic variation and Groups II and III displaying more uniform resistance performance.Principal component analysis(PCA)confirmed these divisions,highlighting the genetic diversity underlying Verticil-lium wilt resistance.Through GWAS,we identified 19 SNPs significantly associated with Verticillium wilt resistance,distributed across three chromosomes.The screening of candidate genes was performed on the transcriptome derived from resistant and susceptible cultivars,combined with gene annotation and tissue expression patterns,and two key candidate genes,Ghir_A01G006660 and Ghir_A02G008980,were found to be potentially associated with Verticillium wilt resistance.This suggests that these two candidate genes may play an important role in responding to Verticillium wilt.Conclusion This study aims to dissect the genetic basis of Verticillium wilt resistance in cotton by using a MAGIC population and GWAS.The study seeks to provide valuable genetic resources for marker-assisted breeding and enhance the understanding of resistance mechanisms to improve cotton resilience against Verticillium wilt. 展开更多
关键词 Upland cotton Verticillium wilt MAGIC population Quantitative trait loci Association analysis
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Research on three-dimensional attack area based on improved backtracking and ALPS-GP algorithms of air-to-air missile
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作者 ZHANG Haodi WANG Yuhui HE Jiale 《Journal of Systems Engineering and Electronics》 2025年第1期292-310,共19页
In the field of calculating the attack area of air-to-air missiles in modern air combat scenarios,the limitations of existing research,including real-time calculation,accuracy efficiency trade-off,and the absence of t... In the field of calculating the attack area of air-to-air missiles in modern air combat scenarios,the limitations of existing research,including real-time calculation,accuracy efficiency trade-off,and the absence of the three-dimensional attack area model,restrict their practical applications.To address these issues,an improved backtracking algorithm is proposed to improve calculation efficiency.A significant reduction in solution time and maintenance of accuracy in the three-dimensional attack area are achieved by using the proposed algorithm.Furthermore,the age-layered population structure genetic programming(ALPS-GP)algorithm is introduced to determine an analytical polynomial model of the three-dimensional attack area,considering real-time requirements.The accuracy of the polynomial model is enhanced through the coefficient correction using an improved gradient descent algorithm.The study reveals a remarkable combination of high accuracy and efficient real-time computation,with a mean error of 91.89 m using the analytical polynomial model of the three-dimensional attack area solved in just 10^(-4)s,thus meeting the requirements of real-time combat scenarios. 展开更多
关键词 air combat three-dimensional attack area improved backtracking algorithm age-layered population structure genetic programming(ALPS-GP) gradient descent algorithm
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无线射频RFID识别协议自动验证方法研究 被引量:3
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作者 宋岚 薛锦云 +3 位作者 胡启敏 谢武平 江东明 游珍 《计算机科学》 CSCD 北大核心 2017年第9期99-104,共6页
Population Protocols是一种受生物启发的计算模型,能够表示无线网络中数量庞大但计算能力弱的多组件间的交互,它为无线传感器网络提供了一种可计算推理的理论框架。将Population Protocol理论引入到RFID识别协议中,提出了RFID识别协议... Population Protocols是一种受生物启发的计算模型,能够表示无线网络中数量庞大但计算能力弱的多组件间的交互,它为无线传感器网络提供了一种可计算推理的理论框架。将Population Protocol理论引入到RFID识别协议中,提出了RFID识别协议系统模型验证框架;构建了标签与阅读器交互产生的状态变迁模型;最后用spin模型检测工具和LTL线性时序逻辑验证了弱公平条件下该模型的自稳定性,为分析与验证无线传感器网络中协议的正确性提供了一种行之有效的方法。 展开更多
关键词 POPULATION Protocols RFID 协议验证 SPIN
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基于CFD-PBM积分矩量法旋风分离器中颗粒聚团的数值模拟 被引量:7
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作者 郑建祥 许帅 王京阳 《流体机械》 CSCD 北大核心 2016年第11期30-35,14,共7页
为了得到颗粒聚团对旋风分离器分离性能的影响,在不同入口颗粒浓度与入口气速下研究其对分离效率的影响。采用雷诺应力模型(RSM)计算湍流流场,通过群体平衡模型(PBM)耦合CFD对颗粒相进行数值计算。研究结果表明:时间为2 s时,旋风分离器... 为了得到颗粒聚团对旋风分离器分离性能的影响,在不同入口颗粒浓度与入口气速下研究其对分离效率的影响。采用雷诺应力模型(RSM)计算湍流流场,通过群体平衡模型(PBM)耦合CFD对颗粒相进行数值计算。研究结果表明:时间为2 s时,旋风分离器内的聚团作用已经趋于稳定,颗粒粒径在1.5μm到3μm范围的颗粒在旋风分离器内基本无法被捕集,而粒径大于5μm的颗粒其分离效率接近于100%;随着入口颗粒浓度的增加,总体分离效率增加,而增加入口气体速度,对分离效率的影响并不是很大。 展开更多
关键词 旋风分离器 群体平衡模型(PBM) 积分矩量法(QMOM) 颗粒聚团 population balance model(PBM) QUADRATURE method of moments(QMOM)
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Progress on Mapping of Quantitative Trait Loci in Crops 被引量:3
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作者 DU Minmin WANG Chao 《Journal of Northeast Agricultural University(English Edition)》 CAS 2008年第3期63-67,共5页
Most important agricultural traits of crops are controlled by many genes. These traits have complicated genetic basis and are difficult for genetic analysis. Due to application of molecular marker techniques in the la... Most important agricultural traits of crops are controlled by many genes. These traits have complicated genetic basis and are difficult for genetic analysis. Due to application of molecular marker techniques in the last two decades, genetic and molecular dissection of quantitative traits has become possible. In this paper, recent progress on mapping of quantitative trait loci in crops was reviewed. 展开更多
关键词 quantitative traits mapping populations high-resolution mapping association analysis
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The impact of plant density and spatial arrangement on light interception on cotton crop and seed cotton yield:an overview 被引量:8
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作者 CHAPEPA Blessing MUDADA Nhamo MAPURANGA Rangarirai 《Journal of Cotton Research》 2020年第3期210-215,共6页
Light attenuation within a row of crops such as cotton is influenced by canopy architecture,which is defined by size,shape and orientation of shoot components.Level of light interception causes an array of morpho-anat... Light attenuation within a row of crops such as cotton is influenced by canopy architecture,which is defined by size,shape and orientation of shoot components.Level of light interception causes an array of morpho-anatomical,physiological and biochemical changes.Physiological determinants of growth include light interception,light use efficiency,dry matter accumulation,duration of growth and dry matter partitioning.Maximum light utilization in cotton production can be attained by adopting cultural practices that yields optimum plant populations as they affect canopy arrangement by modifying the plant canopy components.This paper highlights the extent to which spatial arrangement and density affect light interception in cotton crops.The cotton crop branches tend to grow into the inter-row space to avoid shade.The modification of canopy components suggests a shade avoidance and competition for light.Maximum leaf area index is obtained especially at flowering stage with higher populations which depicts better yields in cotton production. 展开更多
关键词 Light interception Plant populations Spatial arrangement Canopy architecture
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Fine Mapping of Fertility Restoring Gene for Cytoplasmic Male Sterility in Cotton (Gossypium spp. ) Using RAPD and SSR 被引量:1
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作者 Li-wang LIU,Wang-zhen GUO,Xie-fei ZHU,Tian-zhen ZHANG(Cotton Research Institute, National Key Laboratory of Crop Genetics and Germplasm Enhancement Nanjing Agricultural University, Nanjing 210095, China) 《棉花学报》 CSCD 北大核心 2002年第S1期21-21,共1页
The heterosis in cotton is much significant,especially in increasing yield andfiber quality.Comparing with hand-emasculation andpollination,and genetic male sterile lines,utilization of CMS lines is much more effectiv... The heterosis in cotton is much significant,especially in increasing yield andfiber quality.Comparing with hand-emasculation andpollination,and genetic male sterile lines,utilization of CMS lines is much more effectiveand economical in producing commercial hybridseeds.Since 1965 in the world,several CMSlines have been developed,such as CMS 展开更多
关键词 GOSSYPIUM COTTON COTTON STERILE fertility Mapping producing tightly ALLELE populations
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The Collaborative Cross mouse genetic reference population designed for dissecting complex traits 被引量:1
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作者 Hanifa Abu Toamih Atamni Mahmoud Egbaria +2 位作者 Yaser Salaymeh Aysar Nashif Fuad A.Iraqi 《中国比较医学杂志》 CAS 北大核心 2016年第8期1-19,共19页
Complex traits are multifactorial traits controlled by polygenic host factors.These trait-related phenotypic characteristics and performance including body weight,blood chemistry,immune cell profiles,as well host susc... Complex traits are multifactorial traits controlled by polygenic host factors.These trait-related phenotypic characteristics and performance including body weight,blood chemistry,immune cell profiles,as well host susceptibility to infectious and chronic diseases.In recent years,tremendous efforts were invested aiming to map the host genetic factors attribute to these traits and subsequently clone the gene/s underlying these loci.In parallel to human studies,a number of mouse models and approaches were developed aimed to enhance the mapping process and the gene cloning.These include of using resources such as F2,backcross,advanced intercross lines,outbred populations,consomic,congenic and recombinant inbred lines(RIL).The constraints of these approaches were the limited resolution mapping of genomic regions of the quantitative trait loci(QTL)associated with the trait of interests,and the limited genetic diversity observed in the parental founders.To overcome these limitations,a new genetically highly diverse recombinant inbred lines of mouse population was established,namely the Collaborative Cross(CC),created from full reciprocal mating of 8 divergent strains of mice:A/J,C57BL/6J,129S1/SvI mJ,NOD/LtJ,NZO/HiL tJ,CAST/Ei,PWK/PhJ,and WSB/EiJ.By intercrossing these eight founders to generate the different CC lines,the genetic makeup of the newly developed resource is completely different from the eight parental lines,and will show heterosis,which subsequently will response differently comparing with their original founders.Finally,our results suggest that it is not essential to defining the phenotypic response of the eight parental lines,prior of assessing the CC lines,because it is believed that genetic interaction of the new genetic makeup of the new lines will reveal new phenotypic response,which completely different from the parental lines.In this report,we present to the community the power of the CC for dissecting variety of complex traits including host susceptibility to infectious and chronic diseases as well body performance traits.Based on our results from a variety of studies,we recommend to the community,that the best strategy of using this population is to aim of phenotyping about 50 and more of CC lines,with limited number of biological replicates(3-4 mice per line),and subsequently using the publicly available high dense genotype information of the CC lines as well the sequence database of the eight founders,it will be possible performing QTL mapping to a unprecedented precision genomic regions less than 1 MB,subsequently lead to identify potential strong candidate genes.These achievements are believed cannot be obtained with any other currently available mouse resource populations. 展开更多
关键词 PHENOTYPIC PARENTAL COLLABORATIVE INBRED populations genomic susceptibility cloning overcome MATING
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逆预测方法在1946~1949年中国人口重建研究中的应用
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作者 米红 张友干 《陕西师范大学学报(哲学社会科学版)》 CSSCI 1996年第S1期124-134,共11页
逆预测方法在1946~1949年中国人口重建研究中的应用米红,张友干西安交通大学经济人口研究所自80年代末以来,国外的历史人口研究有了长足的进步和发展①,究其原因是国外的一些著名人口学者如:R·李,瑞格雷和斯科夫... 逆预测方法在1946~1949年中国人口重建研究中的应用米红,张友干西安交通大学经济人口研究所自80年代末以来,国外的历史人口研究有了长足的进步和发展①,究其原因是国外的一些著名人口学者如:R·李,瑞格雷和斯科夫等借鉴现代人口分析方法与技术,并结合国... 展开更多
关键词 POPULATION PROBABILITY and STATISTICS LIFE TABLE
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’93回眸:青年文化无热点
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作者 张士军 《中国青年研究》 CSSCI 北大核心 1994年第1期35-36,共2页
近几年,几乎每年都要产生波及整个青年群落大的文化热点。1990年大学生的“寻找毛泽东现象”、“汪国真现象”;1991年京城“文化衫现象”、“红太阳亡带热”;1992年“王朔现象”、“摇滚狂潮”、“下海潮”。
关键词 Central PLACE Theory commercial activities RURAL MARKET spatial combination urban systems THRESHOLD POPULATION
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Identification of DNA Markers for Cotton Leaf Curl Disease (CLCD) in Cotton (Gossypium hirsutum L. )
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作者 Mehboob-ur-RAHMAN N.ASLAM +3 位作者 M.ASIF T.A.MALIK K.A.MALIK Y.ZAFAR 《棉花学报》 CSCD 北大核心 2002年第S1期17-17,共1页
Epidemic of cotton leaf curl virus disease(CLCD)was the compelling factor to devise newstrategies in cotton breeding programs ofPakistan.The evaluation of cotton genotypesagainst the CLCD resistance is difficult,expen... Epidemic of cotton leaf curl virus disease(CLCD)was the compelling factor to devise newstrategies in cotton breeding programs ofPakistan.The evaluation of cotton genotypesagainst the CLCD resistance is difficult,expensive and time consuming in field andespecially in greenhouse due to unevendistribution of the disease.A 展开更多
关键词 COTTON GOSSYPIUM COTTON BREEDING GREENHOUSE consuming expensive devise programs populations
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Tagging and Mapping of QTLs Controlling Lint Yield and Yield Components in Upland Cotton Using SSR and RAPD Markers
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作者 Tian-zhen ZHANG,Jian-mei YAN, Yao-ting WU, Wang-zhen GUO, Xie-fei ZHU(Cotton Research Institute, National Key Laboratory of Crop Genetics & Germplasm Enhancement,Nanjing Agricultural University, Nanjing 210095, China) 《棉花学报》 CSCD 北大核心 2002年第S1期23-23,共1页
Three F<sub>2</sub> populations of cotton(Gossypiumhirsutum L.)from the crosses of Simian 3×TM-1,Simian 3 × CARMEN andXiangzamian2 were characterized for RAPD andSSR.301 pairs of SSR primers an... Three F<sub>2</sub> populations of cotton(Gossypiumhirsutum L.)from the crosses of Simian 3×TM-1,Simian 3 × CARMEN andXiangzamian2 were characterized for RAPD andSSR.301 pairs of SSR primers and 1040 RAPDPrimers were used in the Simian 3 × TM-1population analysis,which resulted in 49polymorphic loci.An analysis of these loci 展开更多
关键词 COTTON COTTON populations polymorphic MAPPING phenotype explained dominance CHROMOSOME CHROMOSOME
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