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中西国民性及国家体制差异的比较分析 被引量:5
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作者 胡承槐 《浙江学刊》 CSSCI 北大核心 2020年第6期15-25,共11页
文章从比较史学的角度出发,分别探讨了中西国民性、国家体制及其相互关系的差异和特殊性。文章认为中西国民性的最大差异在于人对自己自我定位的差异,这一差异决定了国家体制组织形式及其功能的差异。文章在比较分析中西国民性、国家体... 文章从比较史学的角度出发,分别探讨了中西国民性、国家体制及其相互关系的差异和特殊性。文章认为中西国民性的最大差异在于人对自己自我定位的差异,这一差异决定了国家体制组织形式及其功能的差异。文章在比较分析中西国民性、国家体制差异的基础上,揭示和论证了中国国民性和国家体制的卓越性,并呼吁以此为基础确立国家自信和文化自信。 展开更多
关键词 国民性 国家体制 “上帝的选民” “群分结构”
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Impacts of Environmental Factors on the Structure Characteristics of Avian Community in Shanghai Woodlots in Spring 被引量:31
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作者 葛振鸣 王天厚 +2 位作者 施文彧 周立晨 薛文杰 《Zoological Research》 CAS CSCD 北大核心 2005年第1期17-24,共8页
From March to May, 2004, we selected 8 typical parks or green lands in Shanghai downtown as the study sites to conduct a ornithological research. During this study, total 55 species of birds were recorded, which inclu... From March to May, 2004, we selected 8 typical parks or green lands in Shanghai downtown as the study sites to conduct a ornithological research. During this study, total 55 species of birds were recorded, which included 31 resident and 24 migratory species. With statistics methodology, we analyzed the avian communities with 10 major environmental factors covering the park area, water percentage, vegetation species, canopy cover, shrub cover, grass cover, hill number, location condition, human quantity, path width, the study results indicated that: (1) the following 7 environmental factors were important to impact the structures of the avian community, they were park area, vegetation species, shrub coverage, grass coverage, hill number, location condition of the parks and path width; (2) the avian community of theses urban parks tended to deteriorate in the bird number and diversity; the man-made lake which was currently promoted in the park designing and planning process would not be good to attract the birds. 展开更多
关键词 Urban avian community Bird diversity Key environmental factor Shanghai park
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Analysis of Genetic Structure of Natural Populations of Castanopsis fargesii by RAPDs 被引量:12
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作者 朱其慧 潘惠新 +3 位作者 诸葛强 尹佟明 邹惠渝 黄敏仁 《Acta Botanica Sinica》 CSCD 2002年第11期1321-1326,共6页
Genetic diversity and population genetic structure in 188 individuals from five natural populations of Castampsis fargesii Franch. were studied by RAPD markers. Three hundred and eighty-five loci were identified with ... Genetic diversity and population genetic structure in 188 individuals from five natural populations of Castampsis fargesii Franch. were studied by RAPD markers. Three hundred and eighty-five loci were identified with 41 oligonucleotide primers, out of which 157 loci were polymorphic and accounted for 40.78% of total genetic diversity at species level. Shannon's indices of diversity (I) and Nei's gene diversity ( h) were 0.459 7 and 0.296 at the species level, respectively. The result showed that genetic variation of C. fargesii populations mainly existed within populations. Genetic differentiation (Hsp-hpop)/Hsp estimated with Shannon's index of diversity and coefficient of gene differentiation (Gst) were 0.047 6 and 0.042 9 respectively, which were confirmed by the analysis of molecular variance (AMOVA). Therefore, it is apparent that within-population variation accounted for 94.97% and among-populations variation accounted for only 5.03% of the total genetic diversity. AMOVA also indicated that there was significant differentiation among populations as well as among individuals within a population. 展开更多
关键词 Castanopsis fargesii natural populations RAPD genetic structure
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Population Distribution and Dynamics of Quercus liaotungensis, Fraxinus rhynchophylla and Acer mono in Dongling Mountain, Beijing 被引量:48
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作者 吴晓莆 郑豫 马克平 《Acta Botanica Sinica》 CSCD 2002年第2期212-223,共12页
The spatial distribution and population dynamics of Quercus liaotungensis Koidz., Fraxinus rhynchophylla Hance and Acer mono Maxim. were studied in three warm temperate deciduous forests in Dongling Mountain, Beijing.... The spatial distribution and population dynamics of Quercus liaotungensis Koidz., Fraxinus rhynchophylla Hance and Acer mono Maxim. were studied in three warm temperate deciduous forests in Dongling Mountain, Beijing. Clumped distributions appeared in most seedlings (≤0.4 m), short saplings (0.4-1 m) and tall saplings (1-2 m). Random distributions appeared in adults of Q. liaotungensis in Plot 1, F. rhynchophylla in Plot 3. The LSD method was used to discern the differences of different aged population. The class distribution of Q. liaotungensis was nearly a reverse-J shape for Plot 1 and Plot 3, suggesting that the population regenerates continuously. The age-structures of F. rhynchophylla and A. mono in Plot 1 and the test results indicated that they would increase continuously. In Plot 2, the class distribution and the test results showed that all populations would not regenerate continuously. 展开更多
关键词 spatial distribution population structure Quercus liaotungensis
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Sampling Strategy Within a Wild Soybean Population Based on Its Genetic Variation Detected by ISSR Markers 被引量:29
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作者 金燕 张文驹 +1 位作者 傅大煦 卢宝荣 《Acta Botanica Sinica》 CSCD 2003年第8期995-1002,共8页
In order to determine an appropriate sampling strategy for the effective conservation of wild soybean (Glycine soja Sieb. et Zucc.) in China, a natural population from Jiangwan Airport in Shanghai was studied for its ... In order to determine an appropriate sampling strategy for the effective conservation of wild soybean (Glycine soja Sieb. et Zucc.) in China, a natural population from Jiangwan Airport in Shanghai was studied for its genetic diversity through the inter-simple sequence repeat (ISSR) marker analysis of a sample set consisting of 100 randomly collected individuals. A relatively large genetic diversity was detected among the samples based on estimation of DNA products amplified from 15 selected ISSR primers, with the similarity coefficient varying from 0.17 to 0.89. The mean expected heterozygosity (He) was 0.171 4 per locus, and Shannon index (1) was 0.271 4. The Principal Coordinate Analysis (PCA) further indicated that genetic diversity of the Jiangwan wild soybean population was not evenly distributed, instead, was presented by a mosaic or clustered distribution pattern. Correlation study between genetic diversity and number of samples demonstrated that genetic diversity increased dramatically with the increase of number of samples within 40 individuals, but the increase became slow and rapidly reached a plateau when more than 40 individuals were included in the analysis. It is concluded that (i) a sample set of approximately 35-45 individuals should be included to represent possibly high genetic diversity when conservation of a wild soybean population ex situ is undertaken; and (ii) collection of wild soybean samples should be spread out as wide as possible within a population, and a certain distance should be kept as intervals among individuals for sampling. 展开更多
关键词 Glycine soja genetic diversity molecular markers population structure sampling strategy
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Research Overview on Urban Plant Community
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作者 廉丽华 申曙光 《Journal of Landscape Research》 2010年第2期43-46,共4页
The concept of plant community and community classification were expatiated, the study history and actuality were summarized, and the developmental trends of phytocoenology were prospected.
关键词 Plant community Community classfication Community structure Community ecology
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Responses of Soil Fauna Structure and Leaf Litter Decomposition to Effective Microorganism Treatments in Da Hinggan Mountains,China 被引量:4
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作者 GAO Meixiang LI Jingke ZHANG Xueping 《Chinese Geographical Science》 SCIE CSCD 2012年第6期647-658,共12页
Microorganisms are nutritious resources for various soil fauna.Although soil fauna grazing affects microorganism composition and decomposition rate,the responses of soil fauna and leaf litter decomposition to added mi... Microorganisms are nutritious resources for various soil fauna.Although soil fauna grazing affects microorganism composition and decomposition rate,the responses of soil fauna and leaf litter decomposition to added microorganism is little understood.In this study,in the coniferous and broad-leaved mixed forest of Tahe County in the northern Da Hinggan Mountains,China,three sampling sites(each has an area of 10 m2) were selected.The first two sites were sprinkled with 250 times(EM1) and 1000 times(EM2) diluted effective microorganism(EM) preparations evenly,and the third site was sprinkled with the same volume of water as a control site.The responses of soil fauna structure and leaf litter decomposition to EM treatment were conducted during three years.The results revealed that EM treatment resulted in significant increase of soil organic matter.The number of soil fauna in the EM1 and EM2 sites increased by 12.88% and 2.23% compared to the control site,and among them springtails and mites showed the highest increase.However,the groups of soil fauna in the EM1 and EM2 sites decreased by 6 and 9,respectively.And the changes in the diversity and evenness index were relatively complicated.EM treatment slowed the decomposition of broad-leaved litter,but accelerated the decomposition of coniferous litter.However,the decomposition rate of broad-leaved litter was still higher than that of coniferous litter.The results of this study suggested that the added microorganisms could help individual growth of soil fauna,and this method led to a change in the process of leaf litter decomposition.This paper did not analyze the activity of soil microorganisms,thus it is difficult to clearly explain the complex relationships among litter type,soil fauna and soil microorganisms.Further research on this subject is needed. 展开更多
关键词 soil fauna leaf litter decomposition effective microorganism treatment Da Hinggan Mountains China
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Development of two microsatellite multiplex PCR systems for high throughput genotyping in Populus euphratica 被引量:1
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作者 Eusemann Pascal Fehrenz Steffen Schnittler Martin 《Journal of Forestry Research》 SCIE CAS CSCD 2009年第A3期195-198,285,共5页
Eighteen microsatellite primer pairs previously developed at Oak Ridge National Laboratory for Populus tremuloides Michx. and Populus trichocarpa Torr. & Gray were screened for amplification in Euphrates poplar, P... Eighteen microsatellite primer pairs previously developed at Oak Ridge National Laboratory for Populus tremuloides Michx. and Populus trichocarpa Torr. & Gray were screened for amplification in Euphrates poplar, Populus euphratica Oliv. Thirteen loci were found to express polymorphisms ranging from two to 17 alleles. The eight most variable loci were selected to set up and optimize two multiplex polymerase chain reaction (PCR) assays. Three populations containing altogether 436 trees were used to characterize the selected loci and ascertain their applicability for parentage analysis and genotyping studies. Through cross-checking of clonal identity against sex of the genotyped trees we estimated the maximum error rate for merging genotypes to be less than 0.045. 展开更多
关键词 clone identification Euphrates poplar genetic fingerprint parentage analysis population structure SSR primers
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Functional Separable Solutions to Nonlinear Diffusion Equations by Group Foliation Method 被引量:5
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作者 HU Jia-Yi QU Chang-Zheng YIN Hui 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第2期193-199,共7页
We consider the functional separation of variables to the nonlinear diffusion equation with source and convection term: ut = (A(x)D(u)ux)x + B(x)Q(u), Ax ≠ 0. The functional separation of variables to thi... We consider the functional separation of variables to the nonlinear diffusion equation with source and convection term: ut = (A(x)D(u)ux)x + B(x)Q(u), Ax ≠ 0. The functional separation of variables to this equation is studied by using the group foliation method. A classification is carried out for the equations which admit the function separable solutions. As a consequence, some solutions to the resulting equations are obtained. 展开更多
关键词 group foliation method functional separation of variable nonlinear diffusion equation symmetry group
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The Least Distributive Lattice Congruence on Commutative Distributive Semiring 被引量:7
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作者 LI Shi-zheng,LI Shan-hai,YU Xiao-ming (Department of Mathematics, Shandong Normal University, Shandong 250014,China) 《Chinese Quarterly Journal of Mathematics》 CSCD 2003年第1期35-43,共9页
In this paper, we describe the least distributive lattice congruence on a commutative distributive semiring.
关键词 SEMIRING commutative distributive semiring distributive lattice congruence
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ANALYSIS OF GROUP MULTIUSER DETECTION BASED ON COALITION GAME THEORY 被引量:1
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作者 Li Cuilian Yang Zhen 《Journal of Electronics(China)》 2009年第6期804-811,共8页
Coalition game theory is introduced to investigate the performance,fairness and stability of decorrelating group multiuser detection receiver,not only from the perspective of individual nodes,but also various coalitio... Coalition game theory is introduced to investigate the performance,fairness and stability of decorrelating group multiuser detection receiver,not only from the perspective of individual nodes,but also various coalitions and the whole system as well. Firstly,to derive how the system scale with coalition size,a stochastic model with transferable payoffs (stochastic TU-model) is provided. Secondly,to find the most preferred coalition structures from the view point of individual nodes,a model with Non-Transferable payoffs (NTU-model) is presented. Theoretical analysis and simulation results suggest that stochasticaly the grand coalition is payoff maximizing for the system as a whole,while individual nodes with good-conditioned channels may prefer local "win-win coalitions". 展开更多
关键词 Coalition game CORE Multiuser detection RATIONALITY
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Characterization of Specific Spoilage Bacteria and Volatile Flavor Compounds of Flavored Crayfish 被引量:3
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作者 YU Mei-juan TAN Huan +1 位作者 HE Shuang YANG Hui 《Agricultural Science & Technology》 CAS 2021年第3期42-50,共9页
It is a common issue in the processing industry of crayfish that flavored crayfish stored at room temperature is perishable.In order to establish an effective putrid prediction mechanism,high-throughput sequencing and... It is a common issue in the processing industry of crayfish that flavored crayfish stored at room temperature is perishable.In order to establish an effective putrid prediction mechanism,high-throughput sequencing and solid phase microextraction gas chromatography-mass spectrometry(SPME-GCMS)were used to analyse the microbial community structure and volatile flavor compounds of normal and putrid crayfish.The results showed that Aeromonas(57%),Macrococcus(7.7%),Vibrio sp.(6.6%),Acinetobacter(5%),Citrobacter(4.9%)and Enterobacter(1.49%)were the main bacterial genus in the refrigerated fresh crayfish(HNA).And Staphylococcus(17.04%),Aeromonas(4.46%),Xanthomonas(4.16%),Streptococcus(4.62%)and Enterococcus(2.77%)were the main bacterial genus in the marinated and refrigerated crayfish(HND).With the spoilage of samples(HNE and HNC),the diversity of bacteria decreased,and the specific spoilage bacteria grew rapidly,mainly Enterococcus,Bacillus,Lactobacillus,Leuconostoc,Weissella.Meanwhile,the volatile compounds in non-spoilage sample(HNA and HND)were mainly alkane compounds,aldehydes compound and esters compounds;and the volatile compounds in spoilage samples were mainly alcohols,acids,benzene compounds,terpenoids,N-containing compounds,S-containing compounds and ethers.This indicated that the contents and types of volatile compounds changed with the sample spoilage and deterioration.Correlation analysis results showed that Enterococcus,Lactobacillus and Bacillus were significantly positively correlated with alcohols,acids,benzene,terpenoids,N-containing compounds,S-containing compounds and ether compounds,while Aeromonas,Megasphaera,Acinetobacter,Citrobacter and Vibrio were significantly positively correlated with alkane compounds and esters compounds,and Leuconostoc were significantly positively correlated with alcohol compounds.These results can provide a theoretical guidance for the storage of cooked flavor crayfish at room temperature. 展开更多
关键词 CRAYFISH High-throughput sequencing SPME-GC-MS Microbial community structure Volatile compounds
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Grid Service Framework: Supporting Multi-Models Parallel Grid Programming
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作者 邓倩妮 陆鑫达 《Journal of Shanghai Jiaotong university(Science)》 EI 2004年第1期56-59,共4页
Web service is a grid computing technology that promises greater ease-of-use and interoperability than previous distributed computing technologies. This paper proposed Group Service Framework, a grid computing platfor... Web service is a grid computing technology that promises greater ease-of-use and interoperability than previous distributed computing technologies. This paper proposed Group Service Framework, a grid computing platform based on Microsoft. NET that use web service to: (1) locate and harness volunteer computing resources for different applications, and (2) support multi-models such as Master/Slave, Divide and Conquer, Phase Parallel and so forth parallel programming paradigms in Grid environment, (3) allocate data and balance load dynamically and transparently for grid computing application. The Grid Service Framework based on Microsoft. NET was used to implement several simple parallel computing applications. The results show that the proposed Group Service Framework is suitable for generic parallel numerical computing. 展开更多
关键词 web service volunteer computing grid computing parallel programming garadigm
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Characteristics of soil microbial community functional and structure diversity with coverage of Solidago Canadensis L 被引量:11
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作者 廖敏 谢晓梅 +2 位作者 彭英 柴娟娟 陈娜 《Journal of Central South University》 SCIE EI CAS 2013年第3期749-756,共8页
The relationship between Solidago canadensis L. invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%, 80%, and ... The relationship between Solidago canadensis L. invasion and soil microbial community diversity including functional and structure diversities was studied across the invasive gradients varying from 0 to 40%, 80%, and 100% coverage of Solidago canadensis L. using sole carbon source utilization profiles analyses, principle component analysis (PCA) and phospholipid fatty acids (PLFA) profiles analyses. The results show the characteristics of soil microbial community functional and structure diversity in invaded soils strongly changed by Solidago canadensis L. invasion. Solidago canadensis L. invasion tended to result in higher substrate richness, and functional diversity. As compared to the native and ecotones, average utilization of specific substrate guilds of soil microbe was the highest in Solidago canadensis L. monoculture. Soil microbial functional diversity in Solidago canadensis L. monoculture was distinctly separated from the native area and the ecotones. Aerobic bacteria, fungi and actinomycetes population significantly increased but anaerobic bacteria decreased in the soil with Solidago canadensis L. monoculture. The ratio of cyl9:0 to 18:1 co7 gradually declined but mono/sat and fung/bact PLFAs increased when Solidago canadensis L. became more dominant. The microbial community composition clearly separated the native soil from the invaded soils by PCA analysis, especially 18: lco7c, 16: lco7t, 16: lco5c and 18:2co6, 9 were present in higher concentrations for exotic soil. In conclusion, Solidago canadensis L. invasion could create better soil conditions by improving soil microbial community structure and functional diversity, which in turn was more conducive to the growth ofSolidago canadensis L. 展开更多
关键词 sole carbon source utilization phospholipid fatty acids structure diversity functional diversity Solidago canadensis L.
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Characteristics of Phytoplankton Community Structure During and After a Bloom of the Dinoflagellate Scrippsiella trochoidea by HPLC Pigment Analysis 被引量:2
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作者 WONG Chun-kwan WONG Chong-kim 《Journal of Ocean University of China》 SCIE CAS 2009年第2期141-149,共9页
A bloom of the dinoflagellate Scrippsiella trochoidea was detected for the first time in inner Tolo Harbor,Hong Kong in 2 000. Water samples were collected at eight stations along a transect passing through a red tide... A bloom of the dinoflagellate Scrippsiella trochoidea was detected for the first time in inner Tolo Harbor,Hong Kong in 2 000. Water samples were collected at eight stations along a transect passing through a red tide patch for microscopic analysis of phytoplankton composition and high-performance liquid chromatography(HPLC) analysis of phytoplankton pigments. During the bloom,the density of dinoflagellates was 1.1×106 cells L-1 within the patch and 8.6×105 cells L-1 outside the patch where the phytoplankton community was dominated by diatoms. After the bloom the S. trochoidea began to decrease in density and was replaced by diatoms as the dominating bloom-causing organisms at all stations,and the density of dinoflagellates at most stations was less than 1.0 × 106 cells L-1. The status of S. trochoidea as the causative species of the bloom was indicated by the presence of peridinin,the marker pigment for dinoflagellates. The shift from dinoflagellates to diatoms was marked by the decline of peridinin and the prevalence of fucoxanthin. Phytoplankton pigment markers also revealed the presence of other minor phytoplankton assemblages such as cryptomonads and blue-green algal. 展开更多
关键词 coastal water HPLC phytoplankton pigments BLOOM Scrippsiella trochoidea
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General Formulations of Finite-field Method Classifiedby Symmetry for Molecular Linear and Nonlinear Polarizabilities
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作者 陈锡华 林晨升 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2001年第5期369-380,共12页
The formulations of the finite-field approach to calculate the linear and non-linear optical coefficients (i, (ij, (ijk and (ijkl of a molecular system with different symmetries have been deduced and summarized. The p... The formulations of the finite-field approach to calculate the linear and non-linear optical coefficients (i, (ij, (ijk and (ijkl of a molecular system with different symmetries have been deduced and summarized. The possible choices of the energy sets of the 48 frequent point groups have been optimized and categorized into 11 classes. With the restriction of symmetry operators, a minimum of 9, no more than 21 energy points have to be calculated in order to determine the coefficients, except in the case of the first class to which C1 point group belongs and in which the 34 non-relative energy points selected in our uniform and general scheme are all needed. The symmetric operators that cause some of the tensor components to vanish have been demonstrated as well. 展开更多
关键词 nonlinear optical polarizability finite-field approach point group symmetry
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Significant population genetic structure detected in the rock bream Oplegnathus fasciatus(Temminck & Schlegel,1844) inferred from fluorescent-AFLP analysis
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作者 肖永双 马道远 +4 位作者 徐世宏 刘清华 王彦丰 肖志忠 李军 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第3期441-450,共10页
Oplegnathusfasciatus (rock bream) is a commercial rocky reef fish species in East Asia that has been considered for aquaculture. We estimated the population genetic diversity and population structure of the species ... Oplegnathusfasciatus (rock bream) is a commercial rocky reef fish species in East Asia that has been considered for aquaculture. We estimated the population genetic diversity and population structure of the species along the coastal waters of China using fluorescent-amplifed fragment length polymorphisms technology. Using 53 individuals from three populations and four pairs of selective primers, we amplified 1 264 bands, 98.73% of which were polymorphic. The Zhoushan population showed the highest Nei's genetic diversity and Shannon genetic diversity. The results of analysis of molecular variance (AMOVA) showed that 59.55% of genetic variation existed among populations and 40.45% occurred within populations, which indicated that a significant population genetic structure existed in the species. The pairwise fixation index Fst ranged from 0.20 to 0.63 and were significant after sequential Bonferroni correction. The topology of an unweighted pair group method with arithmetic mean tree showed two significant genealogical branches corresponding to the sampling locations of North and South China. The AMOVA and STRUCTURE analyses suggested that the O.fasciatus populations examined should comprise two stocks. 展开更多
关键词 Oplegnathusfasciatus fluorescent-AFLP genetic diversity genetic struc^a'e
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On weakly S-embedded subgroups of finite groups 被引量:3
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作者 LI JinBao CHEN GuiYun CHEN RuiFang 《Science China Mathematics》 SCIE 2011年第9期1899-1908,共10页
Let H be a subgroup of a group G. Then H is said to be S-quasinormal in G if HP = PH for every Sylow subgroup P of G; H is said to be S-quasinormally embedded in G if a Sylow p-subgroup of H is also a Sylow p-subgroup... Let H be a subgroup of a group G. Then H is said to be S-quasinormal in G if HP = PH for every Sylow subgroup P of G; H is said to be S-quasinormally embedded in G if a Sylow p-subgroup of H is also a Sylow p-subgroup of some S-quasinormal subgroup of G for each prime p dividing the order of H. In this paper, we say that H is weakly S-embedded in G if G has a normal subgroup T such that HT is an S-quasinormal subgroup of G and H VIT ≤ HSE, where HSE denotes the subgroup of H generated by all those subgroups of H which are S-quasinormally embedded in G. Some results about the influence of weakly S-embedded subgroups on the structure of finite groups are given. 展开更多
关键词 finite groups weakly S-embedded subgroups the generalized Fitting subgroups supersolublegroups p-nilpotent groups
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Analysis of solid particle clusters in coherent structures of turbulent channel flow 被引量:3
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作者 LU Hao WANG Bing +2 位作者 ZHANG HuiQiang QIN JianXiu WANG XiLin 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第10期2525-2530,共6页
A particle-laden turbulent channel flow is investigated to study particle clusters in large-scale turbulent coherent structures. The fluid phase is calculated by large eddy simulation and particles are tracked using L... A particle-laden turbulent channel flow is investigated to study particle clusters in large-scale turbulent coherent structures. The fluid phase is calculated by large eddy simulation and particles are tracked using Lagrangian trajectory method. The flow Reynolds number is 180 based on the friction velocity and half-width of the channel. The particle is lycopodium with St=0.93 which may well follow the fluid phase. The mean and fluctuating velocities of both two phases are obtained, which are in good agreement with previous data. The strongest accumulations of particles in low-speed streak structures are observed at y~=l 1.3. Moreover, once particles are captured in low-speed streaks, most of them will reside there for a long period. Particles clustered in low-speed streaks obtain smaller instantaneous wall-normal and spanwise velocities than those out of there, which induce a larger particle flux into low-speed streaks than that out of there. The study is important for understanding particle dispersion mechanisms in gas-particle turbulent channel flows. 展开更多
关键词 particle cluster preferential concentration low-speed streak coherent structure large eddy simulation Lagrangiontrajectory method
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Controlling the solid-state luminescence of gold(I) N-heterocyclic carbene complexes through changes in the structure of molecular aggregates 被引量:2
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作者 Arruri Sathyanarayana Shin-ya Nakamura +3 位作者 Kyohei Hisano Osamu Tsutsumi Katam Srinivas Ganesan Prabusankar 《Science China Chemistry》 SCIE EI CAS CSCD 2018年第8期957-965,共9页
Thermally stable, solid-state luminescent organic materials are highly desired for the development of practical applications.Herein we synthesized new gold(I) complexes with N-heterocyclic carbene ligands, which have ... Thermally stable, solid-state luminescent organic materials are highly desired for the development of practical applications.Herein we synthesized new gold(I) complexes with N-heterocyclic carbene ligands, which have the ability to form strong metalorganic bond. Consequently, their thermochemical stability is enhanced at temperatures around 300 °C. Precise design of the molecular structure of the ligands, with a focus on ensuring low steric hindrance around Au atoms in order to limit disturbances to Au/Au interactions, provided a complex with a densely packed crystal with a shorter intermolecular Au–Au distance(3.17 ?)than the typical distance. In the solid state, this complex exhibited strong aurophilic interactions, which generated intense phosphorescence even in air at room temperature(quantum yield=16%) in spite of absence of any phosphorescence in solution.This behavior is characteristic for solid-state luminescence referred to as aggregation-controlled emission. Furthermore, the gold(I) complex displays capacity for mechano-and vapo-chromism—that is, the ability to change color reversibly in response to the application of external stimuli. We believe that the proposed design framework, which involves controlling thermal stability and luminescence property separately, provides a new opportunity for the development of practical applications using solid-state luminescent organic molecules. 展开更多
关键词 Au complex N-heterocyclic carbene phosphorescence mechanochromism aggregation-induced emission
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