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asymmetric competition for light varies across functional groups

Journal of Plant Ecology 2017年第1期10卷 74-80页

作者： Qiang Guo Xiulian Chi Zongqiang Xie Zhiyao Tang Department of Ecology College of Urban and Environmental Sciences and Key Laboratory of Earth Surface Processes of the Ministry of EducationPeking University5 Yiheyuan RoadBeijing 100871China National Resource Center for Chinese Materia Medica China Academy of Chinese Medical SciencesBeijing 100700China 3 State Key Lab oratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesNo.20 NanxincunXiangshanBeijing 100093China

Aims asymmetric competition for light may depress the growth rates(GRs)to different extents for different-sized tree *** responses of different functional groups to light availability result that tree individuals of different functional groups may experience different competition intensities,*** and deciduous species grow faster and demand more light than understory and evergreen *** this study,we estimated the effects of asymmetric competition for light using individual GRs and explored the effects of asymmetric competition on growth among different functional groups(*** *** species and deciduous *** species).Methods We measured growth in circumference to determine the radial increments of a total of 2233 stems with diameter at breast height≥5.0 cm in a permanent plot(140×80 m^(2))located in a typical evergreen and deciduous broadleaved mixed forest on Mt Shennongjia,*** of the measurements were carried out at~6-month intervals every April and October from 2012 to 2014,and biomass of each individual was calculated based on its diameter and species-specific *** then calculated GRs of annual biomass growth(growth between October and the next October).Considering the hypothesis that asymmetric competition for light among trees of different sizes may result in a steeper allometric growth curve with increasing tree size,we further divided the sampled trees into different subsets according to their height,at intervals of 1 m,and then fitted the scaling relationship between the logarithm of the biomass GR(logGR)and the logarithm of diameter(logD)for each height class using standardized major axis ***,we used simple linear regression to test whether the scaling exponent was related to tree *** above analyses were conducted for the annual growth of all tree species,canopy species,understory *** species and deciduous *** *** findings We observed a conca

关键词： asymmetric competition tree height metabolic scaling theory tree growth functional group

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Technological Breakthrough and Domestic Substitution of Key Products Based on asymmetric competition:Taking the Integrated Circuit Industry as an Example

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Frontiers of Business Research in China 2023年第3期17卷 379-406页

作者： LIU Jianli LI Xianjun Institute of Industrial Economics Chinese Academy of Social SciencesBeijing 100006China

Integrated circuit is a typical key product in the digital economy *** external containment,breakthroughs in core technologies of integrated circuit are confronted with barriers of first movers in underlying technological ecology and with their threats of decoupling from the supply ***,China has various bottlenecks in the proprietary industrial ecosystem,and domestic substitution lacks effective overall ***,it is essential to apply the underlying logic of asymmetric competition and to leverage a relatively complete industrial system,abundant application scenarios,solid talent base,and the institutional advantages of the new system for mobilizing resources nationwide to break through in integrated circuit manufacturing technologyand in domestic *** such,it is necessary to further strengthen the top-level design,leverage the advantages of the new system for mobilizing resources nationwide to enhance the institutiona1lguarantee for domestic substitution of bottlenecks,and enhance basic research to consolidate the technological foundation for domestic ***,we should implement talent strategy to enhanceethe driving force of human resource for domestic substitution *** should also further opening-up and cooperation policy to create an open domestic substitution *** addition,we should increase counter-cyclical investment to nurture leaderssin asymmetric competition,and seize the demand window to drive domestic substitution with"epoch-making products."

关键词： key products technological catch-up domestic substitution asymmetric competition integrated circuit

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Problems with models assessing influences of tree size and inter-tree competitive processes on individual tree growth:a cautionary tale

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Journal of Forestry Research 2022年第2期33卷 565-577页

作者： P.W.West D.A.Ratkowsky Forest Research Centre Southern Cross UniversityLismoreNSWAustralia Tasmanian Institute of Agriculture University of TasmaniaHobartTASAustralia

In forest growing at any one site, the growth rate of an individual tree is determined principally by its size, which reflects its metabolic capacity, and by competition from neighboring trees. Competitive effects of a tree may be proportional to its size;such competition is termed ‘sym-metric’ and generally involves competition below ground for nutrients and water from the soil. competition may also be ‘asymmetric’, where its effects are disproportionate to the size of the tree;this generally involves competition above ground for sunlight, when larger trees shade smaller, but the reverse cannot occur. This work examines three model systems often seen as exemplars relating individual tree growth rates to tree size and both competitive processes. Data of tree stem basal area growth rates in plots of even- aged, monoculture forest of blackbutt (Eucalyptus pilularis Smith) growing in sub-tropical eastern Australia were used to test these systems. It was found that none could distin-guish between size and competitive effects at any time in any one stand and, thus, allow quantification of the contribution of each to explaining tree growth rates. They were prevented from doing so both by collinearity between the terms used to describe each of the effects and technical problems involved in the use of nonlinear least-squares regression to fit the models to any one data set. It is concluded that quite new approaches need to be devised if the effects on tree growth of tree size and competitive processes are to be quantified and modelled successfully.

关键词： Symmetric competition asymmetric competition Tree growth rate Growth modeling Nonlinear modeling

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How reproductive allocation and flowering probability of individuals in plant populations are affected by position in stand size hierarchy,plant size and CO_(2) regime

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Journal of Plant Ecology 2008年第4期1卷 207-215页

作者： Caroline Brophy David J.Gibson Peter M.Wayne John Connolly School of Mathematical Sciences Environmental and Ecological Modelling GroupUniversity College DublinBelfieldDublin 4Ireland Department of Plant Biology Center for EcologySouthern Illinois UniversityCarbondaleIL 62901-6509USA Harvard Medical School Osher Research Center Landmark Center Suite 22A401 Park DrBostonMA 02215USA

Aims We investigate the effect of position within a size-structured population on the reproductive allocation(RA)and flowering probability of individual plants of Sinapis *** also assess the effects of plant size and changing level of CO_(2) on both *** Sinapis arvensis L.,(field mustard),an annual agricultural weed,was grown in monoculture at six densities under ambient and elevated CO_(2) in a study with 84 *** aboveground biomass and reproductive biomass were *** density produced a wide range of mean plant sizes across stands and size hierarchies within ***(;40%)individuals had zero reproductive *** a novel modelling approach,we analysed the joint effects of position in stand size hierarchy,plant size and CO_(2) on RA and flowering probability of *** Findings We found a strong effect of position within the size hierarchy of individuals in a population:for an individual of a given size,greater size relative to neighbours substantially increased RA and flowering probability at a single harvest *** was no other effect of plant size on *** found a positive effect of elevated CO_(2) on RA regardless of position within the size *** observed patterns could impact doubly on the reproductive biomass(R)of small ***,because RA is not affected by size,smaller plants will have smaller R than larger plants;and second,for smaller plants lower down in a population size hierarchy,their RA and hence R will be further *** results suggest that size relative to neighbours may be independent of and more important than direct abiotic effects in determining *** studies are required to evaluate how these observed patterns generalize to other populations in non-experimental conditions.

关键词： asymmetric competition neighbour effects nonreproducing plants stand effects Sinapis arvensis

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上游垄断、非对称竞争与社会福利

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产业经济 2012年第2期

作者：刘瑞明石磊

本文从“上游市场垄断、下游市场竞争”的非对称竞争视角试图回答如下疑问：(1)为什么近年来部分大中型国有企业的利润如此丰厚；(2)国有企业的垄断地位如何妨碍了经济增长和社会福利；(3)为什么民营企业不能快速发展壮大。研究发现，... 详细信息

本文从“上游市场垄断、下游市场竞争”的非对称竞争视角试图回答如下疑问：(1)为什么近年来部分大中型国有企业的利润如此丰厚；(2)国有企业的垄断地位如何妨碍了经济增长和社会福利；(3)为什么民营企业不能快速发展壮大。研究发现，国有企业的盈利条件要求国有企业边际成本与民营企业边际成本的比值足够小，而这又取决于市场中企业的数量和所有制结构。维持国有企业在上游市场的垄断相当于给予其一种隐性补贴，这构成了部分大中型国有企业巨额利润的主要来源。本文还发现，上游市场放开竞争有助于民营企业的发展和改善社会福利。

关键词：上游垄断下游竞争非对称竞争国企利润社会福利 upstream market monopoly downstream market competition asymmetric competition SOEs' profits social welfare

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自然垄断行业不对称规制研究

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产业经济 2010年第10期

作者：殷继国

不对称规制是规制机构对自然垄断行业处于不同市场条件下的经营者予以区别对待的规制。实施不对称规制的经济学理论依据是有效竞争理论，法理依据是公共利益理论和实质公平理论，前提条件是不对称竞争的存在。主导经营者的认定标准主要... 详细信息

不对称规制是规制机构对自然垄断行业处于不同市场条件下的经营者予以区别对待的规制。实施不对称规制的经济学理论依据是有效竞争理论，法理依据是公共利益理论和实质公平理论，前提条件是不对称竞争的存在。主导经营者的认定标准主要有市场份额及竞争者数量、控制关键的网络系统资源、市场进入壁垒、利润水平和对竞争者的影响力。不对称规制与反垄断规制均为自然垄断行业的规制手段，两者既有联系又有区别，需要采取措施予以协调。

关键词：自然垄断不对称规制不对称竞争主导经营者反垄断规制 natural monopoly asymmetric regulation asymmetric competition leading operator antitrust regulation

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