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A Rapid Assessment of Scleractinian and Non-Scleractinian Coral Growth Forms Along the Saudi Arabian Coast, Red Sea
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作者 Abdulmohsin A.Al-Sofyani N.Marimuthu J.Jerald Wilson 《Journal of Ocean University of China》 SCIE CAS 2014年第2期243-248,共6页
In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Is... In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Islands(44.55%±11.10% cover) followed by tabular forms in the Doga Islands(ranging between 18%±6.47% and 18.30%±9.47% cover). Digitate forms were rarely found along the coast except at Maqna. Among the five growth forms of non-Acroporid corals, we observed maximum cover of branching forms in the Yanbu offshore area(58.89%±15.11% cover) followed by the Jeddah coast(24.76%±14.04% cover). The Millepora spp., a non-Scleractinian coral, was abundant at all the near-shore sites, such as Jeddah(10.70%±8.21%) and Al-Wajh(9.81%±6.69%). The live coral cover(including both Scleractinian and non-Scleractinian corals) of Saudi Red Sea coast was seen to be higher in the north and gradually decrease towards the south. Principal Component analysis showed that the contribution of Acroporid corals was greater in the southern region than in the northern and middle regions, but vice-versa in the case of non-Acroporid corals. Bray-Curtis cluster analysis categorized all the study sites into two major clusters with 60% similarity. Among them, one cluster-forming sites from Maqna to Masturah(Northern region) and the second one comprised the middle and southern regions(Jeddah to Farassan Islands), and one outlier Rabigh. 展开更多
关键词 造礁石珊瑚 沙特阿拉伯 快速评估 海岸 生长形态 红海 最大覆盖 主成分分析
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Characteristics of life-form and growth-form of plant species in an alpine ecosystem of North-West Himalaya 被引量:4
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作者 R. K. Vashistha Neelam Rawat +3 位作者 A. K. Chaturvedi B. P. Nautiyal P. Prasad M. C. Nautiyal 《Journal of Forestry Research》 SCIE CAS CSCD 2011年第4期501-506,共6页
The present study was conducted in the alpine pastures of Tungnath (30° 14' N and 79° 13' E) to observe life-form and growth-form patterns of alpine plant species under grazed and ungrazed conditions and... The present study was conducted in the alpine pastures of Tungnath (30° 14' N and 79° 13' E) to observe life-form and growth-form patterns of alpine plant species under grazed and ungrazed conditions and to work out the plant life form spectrum. Species were categorized as plant habit, height and length of growth-cycle and life-form classes according to Raunkiaer's system. The results show that in total of 68 species at grazed site, hemicryptophytes (He) accounted for 50.00% species, followed by cryptophytes (26.47%), chamaephytes (16.18%), phanemphytes (4.41%) and therophytes (2.94%). At the ungrazed site in 65 plant species, hemicryptophytes (He) accounted fo'r 49.23% species, cryptophytes (26.15%), chamaephytes (15.38%), phanerophytes (6.15%) and ther6phytes (3.08 % species). In general, hemicrptophyte are dominant^in both sites i.e. graged and ungrazed. Growth form categories were classified as forbs, shrubs, grasses and sedges'and undershrubs, according to plant habit and height. On the basis of length of the growth cycle, species were categorized as plant species of short growth cycle, intermediate growth cycle and long growth cycle. The short forbs of plant habit and height, had the highest emergence, and grasses and sedges had the lowest emergence in representative species. Percentage of species with long growth cycle was highest in both sites. 展开更多
关键词 ALPINE biological spectrum growth form HIMALAYA life
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Parameters in wind-wave frequency spectra and their bearings on spectrum forms and growth 被引量:15
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作者 Wen Shengchang (S. C. Wen), Zhang Dacuo Guo Peifang, and Chen Bohai Institute of Physical Oceanography, Ocean University of Qingdao (formerly, Shandong College of Oceanography), Qingdao, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1989年第1期15-39,共25页
The spectrum variance m0, peak frequency ω0 and peakness factor p are expressed in terms of nondimensional fetch and duration by making use of relations which are derived through comparing and analyzing existing empi... The spectrum variance m0, peak frequency ω0 and peakness factor p are expressed in terms of nondimensional fetch and duration by making use of relations which are derived through comparing and analyzing existing empirical formulas for the growth of significant wave height and period. The main features of spectrum growth as specified by these parameters agree with those of the JONS-WAP experiments. For given wind speed and fetch, the high frequency parts beyond the peaks of shallow water spectra almost coincide with that of the corresponding deep water spectrum, whereas the low frequency parts differ appreciably. The method developed in this paper predicts smaller significant wave height as well as smaller wave period for shallow water spectra in contrast to the theoretical result of Kitaigorodskii ef al, in which the peak frequency, and consequently the significant wave period, remains basically unchanged for different water depths. Spectra are further reduced to a form in which only significant wave height and period are left as parameters, the peakness factor being replaced by the wave steepness through an empirical relation between them. Spectra in this form have been verified by observations. 展开更多
关键词 Parameters in wind-wave frequency spectra and their bearings on spectrum forms and growth wave
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Isothermal grain growth of reactive spray formed 7075 alloys in semi-solid state 被引量:5
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作者 HuiminLiu HuaCuit BinYang JishanZhang 《Journal of University of Science and Technology Beijing》 CSCD 2004年第5期411-414,共4页
The grain growth behavior in reactive spray formed 7075+2.91 vol percent TiCAl alloy was studied and compared with that of spray formed 7075 Al alloy at semi-solid state. Theeffects of in-situ TiC particles on the mic... The grain growth behavior in reactive spray formed 7075+2.91 vol percent TiCAl alloy was studied and compared with that of spray formed 7075 Al alloy at semi-solid state. Theeffects of in-situ TiC particles on the microstructure of spray formed 7075 Al alloy were alsoinvestigated. The specimens were heat-treated isothermally at various temperatures between thesolidus and liquidus of 7075 Al alloy for times in the range of 10-60 min, then quenched in water.The microstructure of reheated specimens was characterized using scanning electron microscopy andoptical microscopy. The grain size was measured using a mean linear intercept method. Results showthat the in-situ TiC particles can effectively retard grain growth and refine the grain at a limitedsize. The grain growth exponent in Arrhenius equation increases from 2 to 3, which indicates thatthe in-situ TiC particles have the significant pinning effect on grain coarsening in the semi-solidstate. 展开更多
关键词 reactive spray forming semi-solid state grain growth in-situ TiC particles
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Non-Local Analysis of Forming Limits of Ductile Material Considering Void Growth
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作者 Youngsuk Kim 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2003年第4期294-299,共6页
The current study performed a finite element analysis of the strain localization behavior of a voided ductile material using a non-local plasticity formulation in which the yield strength depends on both an equivalent... The current study performed a finite element analysis of the strain localization behavior of a voided ductile material using a non-local plasticity formulation in which the yield strength depends on both an equivalent plastic strain measurement (hardening parameter) and Laplacian equivalent. The introduction of gradient terms to the yield function was found to play an important role in simulating the strain localization behavior of the voided ductile material. The effect of the mesh size and characteristic length on the strain localization were also investigated. An FEM simulation based on the proposed non-local plasticity revealed that the load-strain curves of the voided ductile material subjected to plane strain tension converged to one curve, regardless of the mesh size. In addition, the results using non-local plasticity also exhibited that the dependence of the deformation behavior of the material on the mesh size was much less sensitive than that with classical local plasticity and could be succe 展开更多
关键词 NON-LOCAL Characteristic length Vbid Damage growth Gradient-dependent plasticity forming limit Strain localization
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Patterns and drivers of plant sexual systems in the dry-hot valley region of southwestern China
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作者 Rong Ma Qi Xu +3 位作者 Yongqian Gao Deli Peng Hang Sun Bo Song 《Plant Diversity》 SCIE CAS CSCD 2024年第2期158-168,共11页
Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and mai... Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and maintenance of plant biodiversity and predicting its responses to environmental change. In this study, we determined the patterns of plant sexual systems and their associations with geographic elements and various life-history traits in dry-hot valley region of southwestern China, an extremely vulnerable ecosystem. Of the 3166 angiosperm species recorded in this area, 74.5% were hermaphroditic,13.5% were monoecious and 12% were dioecious, showing a high incidence of diclinous species. Diclinous species were strongly associated with tropical elements, whereas hermaphroditic species were strongly associated with temperate and cosmopolitan elements. We also found that hermaphroditism was strongly associated with showy floral displays, specialist entomophily, dry fruits and herbaceous plants.Dioecy was strongly associated with inconspicuous, pale-colored flowers, generalist entomophily, fleshy fruits, and woody plants, whereas monoecy was strongly associated with inconspicuous, pale-colored flowers, anemophily, dry fruits, and herbaceous plants. In addition, hermaphroditic species with generalist entomophily tended to flower in the dry season, whereas diclinous species with specialist entomophily tended to flower in the rainy season. However, independent of sexual systems, plants that produce dry fruits tended to flower in the rainy season and set fruits in the dry season, but the opposite pattern was found for fleshy fruit-producing plants. Our results suggest that in the dry-hot valleys, plant sexual systems are associated with geographic elements as well as various life-history traits that are sensitive to environmental change. 展开更多
关键词 Floral traits Fruit type growth form Pollination system Reproductive phenology
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西双版纳热带雨林不同生长型木本植物功能多样性
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作者 陈燕旋 黄小波 +8 位作者 郎学东 唐荣 张锐 李聪 李俊松 李有寿 王校海 苏建荣 李帅锋 《林业科学研究》 CSCD 北大核心 2024年第3期37-48,共12页
[目的]通过分析西双版纳热带雨林不同生长型木本植物功能性状的差异,揭示热带雨林不同生长型木本植物功能多样性的变化规律以及影响因素。[方法]本文基于西双版纳国家级自然保护区勐仑、补蚌和尚勇等片区3块1 hm2动态监测样地的调查数... [目的]通过分析西双版纳热带雨林不同生长型木本植物功能性状的差异,揭示热带雨林不同生长型木本植物功能多样性的变化规律以及影响因素。[方法]本文基于西双版纳国家级自然保护区勐仑、补蚌和尚勇等片区3块1 hm2动态监测样地的调查数据和木本植物功能性状数据,利用单因素方差分析、主成分分析、Pearson相关分析、冗余分析以及多元线性回归分析等方法,分析西双版纳热带雨林不同生长型木本植物功能多样性的差异,阐明热带雨林木本植物群落的功能特征及主要影响因子。[结果](1)乔木的叶面积、叶碳含量、叶干物质含量的群落加权平均值均显著高于灌木和藤本,而藤本叶氮含量和比叶面积的群落加权平均值显著高于乔木和灌木。(2)乔木功能丰富度和功能离散度高于灌木和藤本,而灌木功能均匀度和功能分异度均高于乔木和藤本。(3)乔木和藤本功能丰富度以及藤本功能离散度随物种丰富度、多度和系统发育多样性的增加而显著增大;乔木功能均匀度和功能分异度随土壤肥力的增大而显著增大,而灌木功能离散度随物种丰富度的增加而增大。(4)植物多度是影响乔木和灌木功能性状群落加权平均值的主要因素,而系统发育多样性、物种丰富度和土壤肥力是影响藤本功能性状群落加权平均值的主要因素。[结论]表明西双版纳热带雨林不同生长型木本植物群落在功能性状和功能多样性之间存在显著差异性,且植物多度和土壤肥力在热带雨林植物群落功能多样性维持机制中起到重要作用。 展开更多
关键词 功能多样性 土壤肥力 多度 热带雨林 生长型 木本植物
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黑色岩系成壤过程中镉和硒的形态转变与迁移特征
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作者 任白琳 麻万诸 章明奎 《水土保持学报》 CSCD 北大核心 2024年第3期391-399,共9页
[目的]黑色岩系含有高量的镉和硒,为明确其在风化成土过程中,岩石镉和硒的形态转变和释放对周围生态环境产生影响。[方法]在浙西北寒武统荷塘组地层的黑色岩系分布区,通过沿地形不同部位(丘陵上坡、丘陵中坡、丘陵下坡、丘间谷底和河谷... [目的]黑色岩系含有高量的镉和硒,为明确其在风化成土过程中,岩石镉和硒的形态转变和释放对周围生态环境产生影响。[方法]在浙西北寒武统荷塘组地层的黑色岩系分布区,通过沿地形不同部位(丘陵上坡、丘陵中坡、丘陵下坡、丘间谷底和河谷阶地)采集土壤剖面分层土样,探讨黑色岩系风化成土及其风化物迁移过程中镉和硒的数量与形态转变规律。[结果]从母岩经母质到土壤,土壤总镉和总硒均呈下降趋势。黑色岩系风化物镉和硒损失随沿丘陵坡地向下迁移搬运距离增加而增加,其中,由坡积物演变为洪积物的过程中,镉和硒的损失大于由残积物演变为坡积物的损失。从风化物中流失的镉和硒以流水扩散方式对下游河流冲积物发育表土镉和硒含量产生影响,但影响程度随距离增加而减小。随着风化物搬运距离增加和土壤的演变,发生碳酸盐结合态镉和残留态镉向水溶性镉、交换性镉、有机质结合态镉、氧化物结合态镉转变,残留态硒逐渐活化转变为交换性硒、有机质结合态硒、氧化物结合态硒。土壤水溶性镉、交换性镉(硒)、有机质结合态镉(硒)呈现向地表增加的趋势;硒的有机富集及表土富集现象比镉更为明显。[结论]黑色岩系风化不仅可通过残留方式直接影响其分布区土壤镉与硒的含量,也可通过流水扩散方式影响周边地区土壤镉和硒的含量。 展开更多
关键词 黑色岩系 风化 土壤发育 化学形态 消长 环境效应
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新型工业化与人类文明新形态
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作者 金碚 《China Economist》 2024年第2期31-53,共23页
人类发展和文明形态的演变和繁荣,表现为艰难地开拓畅通之途。不同文明形态间的融合畅通意味着人类文明的更大进步。人类文明进程所面临的根本问题是,多样化的文明形态如何实现相互畅通、共存共荣?工业化的基本逻辑:机器替代人力,创新... 人类发展和文明形态的演变和繁荣,表现为艰难地开拓畅通之途。不同文明形态间的融合畅通意味着人类文明的更大进步。人类文明进程所面临的根本问题是,多样化的文明形态如何实现相互畅通、共存共荣?工业化的基本逻辑:机器替代人力,创新改变世界;无论“陆权”“海权”,工业能力是实权。新型工业化的经济学叙事原则就是:脱胎于传统工业化,又升华自传统工业化;扬弃传统工业化之弊端,又发扬传统工业化之张力。经济全球化多彩新格局的形成,可以获得中国创造的人类文明新形态的建构性支撑。同时,中国的新型工业化也可以获得经济全球化新格局的更大空间和多样化体系拓展。中国新型工业化是经济全球化新格局的创造性力量,不仅创造中华文明新形态,而且促进协调解决了世界不同文明形态的共存共荣问题。经济全球化需要建立和维护的是“安全畅通、规则平等、承认差异”的世界市场经济秩序。从经济学范式的底层逻辑说,必须从工具理性的一维执念变革为理性、文化、制度三维范式承诺,以体现人类文明新形态内涵的丰富性。 展开更多
关键词 人类文明新形态 工业文明 经济增长 新型工业化 经济全球化 多样化文明形态
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基于δ^(13)C估算水分利用效率的2种模型比较——以峨眉山雷洞坪植物为例
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作者 陈淼 刘顺 +2 位作者 许格希 陈健 史作民 《陆地生态系统与保护学报》 2024年第2期14-23,共10页
【目的】通过对基于碳稳定同位素值(δ^(13)C)估算水分利用效率(iWUE)的2种模型(是否考虑叶肉导度,gm)之间差异的研究,有助于进一步理解gm对植物iWUE的影响。【方法】选择峨眉山雷洞坪针阔混交林中不同生长型植物,采集了48个物种的117... 【目的】通过对基于碳稳定同位素值(δ^(13)C)估算水分利用效率(iWUE)的2种模型(是否考虑叶肉导度,gm)之间差异的研究,有助于进一步理解gm对植物iWUE的影响。【方法】选择峨眉山雷洞坪针阔混交林中不同生长型植物,采集了48个物种的117个叶片样品,通过测定其叶片δ^(13)C,对比了早期估算iWUE模型(iWUEsim模型,将gm看作无穷大)与包含gm效应的iWUE模型(iWUEmes模型)之间的iWUE差异(iWUE_(difference)),以及这种差异随植物生长型变化的趋势。【结果】结果显示,iWUEsim的平均值(42.23±1.33μmol·mol^(-1))显著高于iWUEmes的平均值(28.10±0.65μmol·mol^(-1)),高估比例为3.64%~72.11%(平均49.58%±1.30%)。不同生长型植物的iWUEsim均显著大于iWUEmes,其中草本植物高估比例3.64%~48.00%(平均29.20%±5.16%),灌木高估比例13.68%~67.73%(平均48.44%±1.83%),乔木高估比例32.04%~72.11%(平均54.08%±1.47%)。此外,叶片功能性状对iWUE_(difference)有显著影响,相比于叶片厚度、叶片干物质含量和单位质量叶片氮含量,单位面积叶片氮含量和比叶重是影响iWUE_(difference)变化的主要因素。【结论】将gm看作无穷大会造成对基于δ^(13)C估算的iWUE的高估,未来估算植物iWUE时应考虑gm的影响。 展开更多
关键词 内在水分利用效率 叶肉导度 碳稳定同位素 植物生长型 单位面积叶片氮含量 比叶重
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氮形态对小白菜根系生长、根区pH及细胞壁组分的影响
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作者 韩瑞锋 郭雨琴 +3 位作者 王玉琢 成永三 侯雷平 张毅 《中国农业科学》 CAS CSCD 北大核心 2024年第11期2215-2226,共12页
【目的】氮素(N)是调控蔬菜作物生长的重要因子,探究氮形态对小白菜根系生长及细胞壁组分的影响,明确根区pH变化与质膜(PM)H^(+)-ATPase的关系,为进一步研究氮素调控植物根系生长发育提供理论基础。【方法】以小白菜(‘华王’)为试材,设... 【目的】氮素(N)是调控蔬菜作物生长的重要因子,探究氮形态对小白菜根系生长及细胞壁组分的影响,明确根区pH变化与质膜(PM)H^(+)-ATPase的关系,为进一步研究氮素调控植物根系生长发育提供理论基础。【方法】以小白菜(‘华王’)为试材,设置3个N素形态(硝态氮(NO_(3)^(-)-N)、铵态氮(NH_(4)^(+)-N)、甘氨酸态氮(Gly-N)),采用营养液水培法,探究无机氮和有机氮调控小白菜根区pH和根细胞壁组分对根系生长的影响,同时探讨氮营养对小白菜根系生长素(IAA)和PM H^(+)-ATPase酶的影响。用根系扫描法和生理试验等方法,测定小白菜的总根长、总根体积、总根表面积和根尖数等根系形态指标以及介质pH、PM H^(+)-ATPase酶活性、IAA含量、细胞壁及其主要组分含量、果胶甲酯酶(PME)、扩张素(EXP)含量等生理指标,并分析根系形态和各生理指标之间的相关性。【结果】Gly-N和NO_(3)^(-)-N均碱化介质pH,且Gly-N碱化介质pH的能力高于NO_(3)^(-)-N处理,NH_(4)^(+)-N酸化介质pH。与NO_(3)^(-)-N处理相比,Gly-N处理显著降低小白菜地上部(40.23%)和根系干物质含量(21.74%)、主根长(55.15%)、总根长(58.63%)、总根表面积(53.12%)、总根尖数(73.07%)、根分叉数(65.39%)、内部链接数(40.91%)和外部链接数(73.94%),提高了根系细胞壁提取率(22.00%)、果胶(47.74%)、纤维素(25.30%)、EXP(109.53%)、PM H^(+)-ATPase酶活性(15.42%)、根冠比(30.33%)、拓扑指数(11.43%)和分形维数(4.32%);NH_(4)^(+)-N处理植株地上部干物质含量、主根长、根分叉数、内部链接数、外部链接数、根系PME活性和IAA含量分别显著降低22.98%、34.30%、35.32%、26.22%、29.02%、36.38%和8.74%,根系PM H^(+)-ATPase酶活性、细胞壁提取率、果胶和半纤维素分别显著提高14.60%、19.38%、22.98%、74.33%。根系形态指标与生理指标之间的相关分析结果表明,总根表面积与总根长、总根尖数、外部链接数、根分叉数呈极显著正相关(P<0.01),与主根长、内部链接数、叶干重呈显著正相关(P<0.05);总根表面积与根直径、扩张素、拓扑指数呈极显著负相关(P<0.01),与果胶、纤维素和分形维数呈显著负相关(P<0.05)。根直径与扩张素、纤维素、分形维数、拓扑指数呈极显著正相关(P<0.01),与果胶呈显著正相关(P<0.05)。【结论】Gly-N和NH_(4)^(+)-N均增加了小白菜根系细胞壁含量,抑制了小白菜根系的伸长生长;Gly-N更有利于果胶和纤维素的积累,NH_(4)^(+)-N有利于半纤维素的积累。 展开更多
关键词 小白菜 氮形态 PH 根系生长 细胞壁
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铵硝配比对樱桃番茄生长发育、产量、品质及氮素吸收的影响 被引量:1
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作者 马超 李雪 +3 位作者 马瑞杰 鄂玉联 邹向东 郑继亮 《中国瓜菜》 CAS 北大核心 2024年第3期121-127,共7页
为探明铵硝配比对樱桃番茄生长发育、产量、品质及氮素吸收的影响,促进樱桃番茄果实品质提升,采用温室大棚育苗移栽的种植方式,分别设置NH_(4)^(+)-N和NO_(3)^(-)-N配比为100∶0(CK)、75∶25(T1)、50∶50(T2)、25∶75(T3)、0∶100(T4)处... 为探明铵硝配比对樱桃番茄生长发育、产量、品质及氮素吸收的影响,促进樱桃番茄果实品质提升,采用温室大棚育苗移栽的种植方式,分别设置NH_(4)^(+)-N和NO_(3)^(-)-N配比为100∶0(CK)、75∶25(T1)、50∶50(T2)、25∶75(T3)、0∶100(T4)处理,测定樱桃番茄不同生育期株高、茎粗、叶面积、SPAD值、植株生物量和果实含氮量、产量及果实品质,计算氮肥累积利用率等。结果表明,果实纵径、果形指数、单果质量和果实硬度均随NO_(3)^(-)-N比例的增加表现为先增加后降低趋势。在果实风味品质方面,T3处理有利于提高果实中可溶性固形物、可溶性糖、有机酸含量和糖酸比,分别较全铵处理增加20.75%、33.10%、34.29%和28.88%。樱桃番茄的株高、叶面积和SPAD值均随NO_(3)^(-)-N比例的增加表现出先升高后降低趋势,除坐果期T3处理略低于T2处理外,其余在T3处理达到峰值。植株累积吸氮量随NO_(3)^(-)-N比例的增加表现出先升高后降低趋势,在T3处理达到最大,为113.33 kg·hm^(-2)。随NO_(3)^(-)-N比例增加樱桃番茄产量表现出先升高后降低趋势,T3处理较CK处理增产17.90%,氮肥累积利用率和氮肥偏生产力分别为226.66%和126.66 kg·kg^(-1)。综合各项指标来看,当NH_(4)^(+)-N与NO_(3)^(-)-N配比为25∶75时,与CK相比可显著促进樱桃番茄生长发育,提高果实产量,改善果实品质。 展开更多
关键词 樱桃番茄 氮素形态 生长发育 产量 品质
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不同铵硝比对高山杜鹃侧枝生长和生理特性影响
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作者 高研 彭绿春 +5 位作者 李世峰 解玮佳 宋杰 张露 熊俊芬 赵正雄 《核农学报》 CAS CSCD 北大核心 2024年第4期785-793,共9页
为探究氮素形态对高山杜鹃侧枝生长的影响,以3年生盆栽高山杜鹃粉精灵为试验材料,单一氮源处理为对照,采用盆栽方式,研究5种不同氮素形态配比供应(铵硝比例分别为T1:100∶0,T2:75∶25,T3:50∶50,T4:25∶75和T5:0∶100)对其营养生长期侧... 为探究氮素形态对高山杜鹃侧枝生长的影响,以3年生盆栽高山杜鹃粉精灵为试验材料,单一氮源处理为对照,采用盆栽方式,研究5种不同氮素形态配比供应(铵硝比例分别为T1:100∶0,T2:75∶25,T3:50∶50,T4:25∶75和T5:0∶100)对其营养生长期侧枝生长、光合特性、代谢酶活性及营养元素积累的影响。结果表明,不同氮素形态下粉精灵不同生长期侧枝干物质积累量、苗高增量和侧枝长度均有所差异,以侧芽萌发期T3处理侧枝干物质积累量最高,T2处理在嫩侧枝期、侧枝半木质化期的苗高增量和侧枝长度均显著高于其他处理。侧枝半木质化期,与T1处理相比,T2处理显著提高净光合速率、蒸腾速率、气孔导度、水分利用率及磷含量,降低胞间二氧化碳浓度;叶片Fe元素吸收量以T1处理最高,Mg元素吸收量以T5处理最高。此外,在不同生长期,硝酸还原酶活性均随硝态氮含量的增加而增加,以嫩侧枝期酶活性最高。综上,不同氮素形态对高山杜鹃粉精灵侧枝生长和生理特性的影响有所差异,且混合氮源处理较单一氮源处理更有利于促进侧枝生长,以铵硝比例75∶25促进侧枝生长及提高养分积累和光合效能效果最好。本研究为筛选适合高山杜鹃生长发育的氮素施用方法提供了理论依据。 展开更多
关键词 高山杜鹃 氮素形态 侧枝生长 生理特性 营养元素
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Short wind pulses consistently change the morphology of roots,but not of shoots,across young plants of different growth forms
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作者 Johannes Heinze Luise Werger +3 位作者 Michael Ogden Thilo Heinken Rainer Hoefgen Ewald Weber 《Stress Biology》 2023年第1期468-476,共9页
Wind is an environmental stimulus that stresses plants of all growth forms at all life-stages by influencing the development,architecture,and morphology of roots and shoots.However,comparative studies are scarce and n... Wind is an environmental stimulus that stresses plants of all growth forms at all life-stages by influencing the development,architecture,and morphology of roots and shoots.However,comparative studies are scarce and no study directly investigated whether shoot and root morphological traits of trees,grasses and forbs differ in their response to short wind pulses of different wind intensity.In this study,we found that across species,wind stress by short wind pulses of increasing intensity consistently changed root morphology,but did not affect shoot morphological traits,except plant height in four species.Wind effects in roots were generally weak in tree species but consistent across growth forms.Furthermore,plant height of species was correlated with changes in specific root length and average diameter.Our results indicate that short-pulse wind treatments affect root morphology more than shoot morphology across growth forms.They further suggest that wind stress possibly promotes root anchorage in young plants and that these effects might depend on plant height. 展开更多
关键词 Wind stress Leaf traits Root traits growth form Morphology
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铅污染矿区中耐铅解磷菌对玉米的促生及根际铅的固化效应
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作者 江润海 温绍福 +4 位作者 朱城强 张梅 杨润玲 王春雪 侯秀丽 《生态环境学报》 CSCD 北大核心 2024年第2期291-300,共10页
矿产资源的开采、冶炼活动造成了一定的生态环境问题,土壤中可溶性重金属随着地表径流和地下渗透造成矿区和周边农田重金属污染。而矿区中土壤微生物对重金属具有一定耐性,研究微生物对植物根际微生态环境的改善作用具有重要意义。在矿... 矿产资源的开采、冶炼活动造成了一定的生态环境问题,土壤中可溶性重金属随着地表径流和地下渗透造成矿区和周边农田重金属污染。而矿区中土壤微生物对重金属具有一定耐性,研究微生物对植物根际微生态环境的改善作用具有重要意义。在矿区废弃地土壤中筛选耐铅(Pb)解磷菌的基础上,将含有菌株分泌物的上清液、菌液、发酵液(上清液+菌株)分别施用到玉米(Zea mays L.)根际土壤中,对比三者对玉米的促生效果及根际土壤铅的形态变化,探究解磷菌对玉米的促生机制及其对土壤铅的固化作用。所筛菌株被鉴定为巴氏克雷伯菌(Klebsiella pasteurii),其通过分泌乙酸、乳酸、酒石酸和草酸对Ca3(PO4)2的溶磷率为26.5%,并能分泌生长素(IAA)。在玉米根际土壤中施用菌株的上清液、菌液和发酵液后,较对照组玉米株高、茎直径、地上与地下生物量均显著增加,其中施用发酵液组增幅最高,较对照组分别增加了128%,216%、266%、147%。同时,3个处理组中玉米地上生物量中铅含量分别降低68.6%、58.1%、70.1%,地下部铅含量分别降低119%、36.7%、39.5%。施用菌株上清液、菌液和发酵液后均使玉米根际土壤中可溶态的铅向稳定态铅转化,这可能是巴氏克雷伯菌在解离土壤磷素的过程中,其解离的磷可能与铅形成稳定态的磷铅化合物,进而降低植物对铅的吸收。由此可以得出,在铅污染土壤中巴氏克雷伯菌能够显著固化重金属铅并抑制玉米对铅的吸收,对玉米具有促生作用,因此,巴氏克雷伯菌在土壤重金属修复和保障农作物食品安全方面具有重要价值。 展开更多
关键词 铅的固化 铅污染矿区 解磷菌 促生 铅的形态 重金属 土壤污染
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基于自由曲面和L-system的红掌生长模型
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作者 邹一波 褚诗贤 +1 位作者 葛艳 陈明 《湖南农业大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第1期85-90,共6页
针对红掌花卉生长可视化中参数难以确定的问题进行研究,提出推导控制点的方法,建立红掌器官模型:采用Bezier曲线结合扫描成型的方法来构造叶柄模型,采用双三次NURBS曲线对佛焰苞进行建模;运用红掌的相关表型数据拟合生长函数,提出基于... 针对红掌花卉生长可视化中参数难以确定的问题进行研究,提出推导控制点的方法,建立红掌器官模型:采用Bezier曲线结合扫描成型的方法来构造叶柄模型,采用双三次NURBS曲线对佛焰苞进行建模;运用红掌的相关表型数据拟合生长函数,提出基于红掌生长规律的微分L-system,可有效模拟红掌的拓扑结构和生长过程;通过虚拟器官表示红掌器官的几何属性,降低微分L-system的复杂度。试验验证提出的方法对红掌各项生长指标拟合度可达0.89以上,并可对每个生长阶段的红掌进行模拟,能有效地对红掌的生长过程进行建模。 展开更多
关键词 红掌 自由曲面建模 L-SYSTEM 生长函数 虚拟器官
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Structural evolution of spray-formed Al-70wt.%Si alloys during iso-thermal holding in the semi-solid state 被引量:2
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作者 ZHANG Di CUI Hua +3 位作者 WEI Yanguang ZHANG Jishan ZHANG Yongan XIONG Baiqing 《Rare Metals》 SCIE EI CAS CSCD 2005年第4期317-324,共8页
The grain growth behavior of spray-formed Al-70wt.%Si alloys was studied in the semi-solid state. The specimens were isothermally heat-treated at various temperatures between the solidus and liquidus of Al-Si alloys a... The grain growth behavior of spray-formed Al-70wt.%Si alloys was studied in the semi-solid state. The specimens were isothermally heat-treated at various temperatures between the solidus and liquidus of Al-Si alloys and then quenched in water. The microstructure of reheated specimens was characterized using optical and scanning electron microscopies. The isothermal holding experiment was carried out to investigate grain growth behavior as a function of holding time and temperature in the semi-solid state. The coarsening mechanism and the effect of porosity on microstructure were also studied. 展开更多
关键词 materials science grain growth behavior spray forming Al-70wt.%Si alloys semi-solid processing
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克氏原螯虾对3种不同生长型沉水植物清水态系统的影响
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作者 刘伟 张泽慧 +3 位作者 高健 袁红 王铭 熊文 《水生态学杂志》 CSCD 北大核心 2023年第3期129-135,共7页
鉴于克氏原螯虾(Procambarus clarkii)是目前全球入侵最广、对淡水生态系统最具破坏性的物种之一,探究其对沉水植物清水态系统的影响,有助于防范克氏原螯虾入侵给浅水湖泊带来的生态风险。通过受控实验,研究了克氏原螯虾对直立型沉水植... 鉴于克氏原螯虾(Procambarus clarkii)是目前全球入侵最广、对淡水生态系统最具破坏性的物种之一,探究其对沉水植物清水态系统的影响,有助于防范克氏原螯虾入侵给浅水湖泊带来的生态风险。通过受控实验,研究了克氏原螯虾对直立型沉水植物轮叶黑藻(Hydrilla verticillata)、冠层型沉水植物穗花狐尾藻(Myriophyllum spicatum)和莲座型沉水植物密刺苦草(Vallisneria denseserrulata)的影响以及不同植物培养系统对理化因子的响应变化。结果显示,直立型轮叶黑藻相对生物减少量(60.5%)大于冠层型穗花狐尾藻(45.7%)和莲座型密刺苦草(39.0%);克氏原螯虾进入后导致3种生长型沉水植物清水态系统的总悬浮物浓度、叶绿素a和营养盐均极显著增高(P<0.01)。研究表明,水生态系统中的克氏原螯虾会直接降低沉水植物生物量,并扰动底泥增加水体的悬浮物、叶绿素a和营养盐浓度,导致水体由清水态向浊水态转变,也会通过直接牧食或扰动破坏,降低沉水植物生物量,最终影响草型清水态系统的稳定性。 展开更多
关键词 克氏原螯虾 轮叶黑藻 密刺苦草 穗花狐尾藻 生长型 清水态
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泡桐无性系早期生长与干形综合选择
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作者 蔡卫佳 王昊 +3 位作者 刘威 罗桂杰 刘旭 王红玲 《林业与环境科学》 2023年第5期20-26,共7页
为筛选出速生和接干能力好的无性系,以江苏省宿迁市的13个泡桐无性系测定林为研究对象,利用混合线形模型对泡桐20个月树高(H_(20)),30个月树高(H_(30))、胸径(D_(30))、材积(V_(30))和30个月时接干能力指数(J_(30))性状进行遗传参数估算... 为筛选出速生和接干能力好的无性系,以江苏省宿迁市的13个泡桐无性系测定林为研究对象,利用混合线形模型对泡桐20个月树高(H_(20)),30个月树高(H_(30))、胸径(D_(30))、材积(V_(30))和30个月时接干能力指数(J_(30))性状进行遗传参数估算,同时,利用基因型综合指数选择法对30月龄泡桐无性系进行早期选择。试验结果表明,泡桐无性系早期生长快,H_(20)、H_(30)、D_(30)、V_(30)和J_(30)平均值分别为4.56 m、6.73 m、10.20 cm、0.0314 m^(3)和0.48;泡桐H_(20)、H_(30)、D_(30)、V_(30)和J_(30)在无性系间达极显著水平,其无性系重复力为0.69~0.99,单株重复力为0.15~0.85,说明遗传和环境因子均为影响泡桐生长的重要因素。生长性状间表型和遗传相关达到显著水平,接干能力指数与D_(30)和V_(30)间表型相关不显著,而与其他性状间的表型和遗传相关系数均达到了显著水平。以泡桐30个月时生长和接干能力指标进行早期选择,综合评选4个优良无性系49、01-23、01-22和4B,无性系入选率30.8%,其生长指标和接干能力指标均高于对照无性系,具有较高的遗传稳定性。 展开更多
关键词 泡桐 无性系 早期生长 干形 多性状选择指数
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经导管动脉栓塞化疗治疗中晚期肝癌的疗效及对甲胎蛋白、转化生长因子-β1的影响
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作者 陈璐 杨静 +3 位作者 祁晓星 姬海利 王占孔 郭浩 《癌症进展》 2023年第21期2348-2351,共4页
目的 探讨经导管动脉栓塞化疗(TACE)治疗中晚期肝癌的疗效及对甲胎蛋白(AFP)、转化生长因子-β1(TGF-β1)的影响。方法 收集82例接受TACE治疗的中晚期肝癌患者的病历资料,分析治疗效果、生存情况、不良反应发生情况,对比治疗前后AFP、T... 目的 探讨经导管动脉栓塞化疗(TACE)治疗中晚期肝癌的疗效及对甲胎蛋白(AFP)、转化生长因子-β1(TGF-β1)的影响。方法 收集82例接受TACE治疗的中晚期肝癌患者的病历资料,分析治疗效果、生存情况、不良反应发生情况,对比治疗前后AFP、TGF-β1、肝功能指标[丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)及总胆红素(TBIL)]、免疫功能指标(CD4^(+)、CD8^(+))水平。结果 82例中晚期肝癌患者治疗6个月后完全缓解(CR)10例(12.20%),部分缓解(PR)31例(37.80%),稳定(SD)24例(29.27%),进展(PD)17例(20.73%),客观缓解率为50.00%(41/82),疾病控制率为79.27%(65/82)。治疗后,中晚期肝癌患者AFP、TGF-β1水平均较治疗前明显下降,差异均有统计学意义(P﹤0.01)。治疗后,中晚期肝癌患者ALT、AST、TBIL、CD4^(+)、CD8^(+)水平均较治疗前升高,差异均有统计学意义(P﹤0.05)。中晚期肝癌患者治疗3、6、9、12个月的生存率分别为100%(82/82)、87.80%(72/82)、81.71%(67/82)、73.17%(60/82),治疗后不良反应总发生率为53.66%(44/82)。结论 将TACE应用于中晚期肝癌患者中,能够有效提高近期疗效及生存率,还可有效改善AFP、TGF-β1水平,抑制中晚期肝癌患者肿瘤细胞的增殖与生长,且治疗后无严重不良反应,安全可行。 展开更多
关键词 经导管动脉栓塞化疗 中晚期肝癌 甲胎蛋白 转化生长因子-Β1
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