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北京东灵山不同坡位辽东栎(Quercus liaotungensis)叶属性的比较 被引量:131
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作者 祁建 马克明 张育新 《生态学报》 CAS CSCD 北大核心 2008年第1期122-128,共7页
植物在山地环境中生存不仅受到海拔等大尺度地形因子的影响,坡位等小尺度地形因子也会对植物产生影响.不同坡位上光照、温度、土壤养分和水分等均会影响到植物的资源利用策略。为比较不同坡位对辽东栎资源利用策略的影响,在北京东灵... 植物在山地环境中生存不仅受到海拔等大尺度地形因子的影响,坡位等小尺度地形因子也会对植物产生影响.不同坡位上光照、温度、土壤养分和水分等均会影响到植物的资源利用策略。为比较不同坡位对辽东栎资源利用策略的影响,在北京东灵山海拔1000~1800m的辽东栎分布范围内针对比叶面积、叶氮含量和叶干物质含量3个重要的叶属性进行了研究。ANOVA统计分析发现,地形和土壤养分及水分等环境因子在不同坡位上出现变化,但只有土壤有机质含量有显著差异。在叶属性中,干物质含量在上坡位最高,下坡位最低,在坡位间差异极显著。比叶面积与叶干物质含量在不同坡位间均成反比关系,在上坡位比叶面积变化一定的情况下,叶干物质含量的变化幅度最小;而比叶面积与叶氮含量仅在上坡位成反比关系。这些结果说明坡位对辽东栎的叶属性有一定的影响,尤其是上坡位的影响最大。 展开更多
关键词 坡位 叶属性 辽东栎 东灵山
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灵石山米槠林优势种群不同叶龄叶属性的研究 被引量:17
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作者 王英姿 洪伟 +4 位作者 吴承祯 郑关关 范海兰 陈灿 李键 《福建林学院学报》 CSCD 北大核心 2009年第3期203-209,共7页
在灵石山100-900 m海拔梯度上米槠林分布的范围内,对米槠林优势种群不同年龄叶片的叶属性及其相关性进行分析。结果表明,叶属性有显著的叶龄间以及种间的差异;不同年龄叶片叶属性之间存在显著的相关性。说明叶片性状是植物长期适应环境... 在灵石山100-900 m海拔梯度上米槠林分布的范围内,对米槠林优势种群不同年龄叶片的叶属性及其相关性进行分析。结果表明,叶属性有显著的叶龄间以及种间的差异;不同年龄叶片叶属性之间存在显著的相关性。说明叶片性状是植物长期适应环境的结果,叶片对不同环境的适应策略不同,不同年龄叶片对相同环境的适应策略也有差别,但各种环境下植物的各种叶片性状满足一定的关系,这种关系是植物适应环境的表现。 展开更多
关键词 优势种群 米槠林 叶属性 养分含量 营养结构 灵石山
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不同放牧模式对贵南县高寒草甸优势种羊茅叶属性的影响 被引量:4
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作者 朱文琰 王娅琳 +4 位作者 杨畅 赵娜 赵新全 徐世晓 孙平 《中国草地学报》 CSCD 北大核心 2021年第6期69-75,共7页
以青海省贵南县高寒草甸的不同放牧管理模式(适度放牧、重度放牧、季节性休牧及封育)草地为对象,通过对不同放牧模式下高寒草甸优势种羊茅8个叶属性的定量分析,研究不同放牧模式对高寒草甸优质牧草羊茅的影响。结果表明:与适度放牧样地... 以青海省贵南县高寒草甸的不同放牧管理模式(适度放牧、重度放牧、季节性休牧及封育)草地为对象,通过对不同放牧模式下高寒草甸优势种羊茅8个叶属性的定量分析,研究不同放牧模式对高寒草甸优质牧草羊茅的影响。结果表明:与适度放牧样地相比,羊茅比叶面积在重度放牧后显著升高(P<0.05),封育后显著下降(P<0.05),叶干物质含量均呈现下降趋势(P<0.05)。放牧使羊茅叶N、P含量表现出增加趋势,N/P表现出降低趋势,在重度放牧样地中表现最为明显(P<0.05)。各样地均有较高N/P,说明P元素是限制羊茅生长的主要营养元素。主成分分析表明,季节性休牧模式下羊茅生长状况较好,重度放牧模式下羊茅生长状况最差。因此,从羊茅叶属性看,应提高休牧模式在草地利用中的比重,降低草地放牧强度,以保证草地质量。 展开更多
关键词 放牧 叶属性 主成分分析 羊茅
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引种紫花槭叶属性的年际变化 被引量:7
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作者 梁鸣 赵大勇 +1 位作者 孙波 杨轶华 《东北农业大学学报》 CAS CSCD 北大核心 2009年第12期29-33,共5页
采用叶色量化结合主要生理指标测定和生物学观测等方法,研究了哈尔滨地区引种的园林绿化秋季色叶树种紫花槭的叶属性年际变化。结果表明,在驯化过程中,紫花槭的叶属性在年份间存在显著差异,从一定程度上反映了引种紫花槭的适应性呈逐年... 采用叶色量化结合主要生理指标测定和生物学观测等方法,研究了哈尔滨地区引种的园林绿化秋季色叶树种紫花槭的叶属性年际变化。结果表明,在驯化过程中,紫花槭的叶属性在年份间存在显著差异,从一定程度上反映了引种紫花槭的适应性呈逐年提高趋势。 展开更多
关键词 紫花槭 叶属性 年际变化
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9种绿化树种叶属性对大气混合污染的响应 被引量:3
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作者 齐淑艳 李婷 《辽宁林业科技》 2009年第5期15-17,47,共4页
研究9种栽植于沈阳某化工厂厂区和沈阳大学南校区绿化树种的叶片数量特征和叶参数对大气污染的响应。结果表明:在化工厂大气混合污染区和校园大气相对清洁区,对叶片形态分类起主导作用的均是叶片的周长和宽度。对以氯气为主大气混合污... 研究9种栽植于沈阳某化工厂厂区和沈阳大学南校区绿化树种的叶片数量特征和叶参数对大气污染的响应。结果表明:在化工厂大气混合污染区和校园大气相对清洁区,对叶片形态分类起主导作用的均是叶片的周长和宽度。对以氯气为主大气混合污染具有较强抗性的植物是五叶地锦、女贞;对以氯气为主大气混合污染比较敏感的植物是桃、榆、皂荚、龙爪槐。 展开更多
关键词 绿化树种 叶属性 面积 型指数
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灵石山不同海拔米槠林优势种叶片δ^(13)C值与叶属性因子的相关性 被引量:5
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作者 王英姿 《生态学报》 CAS CSCD 北大核心 2013年第10期3129-3137,共9页
对灵石山海拔157—842 m(分9个海拔梯度,分别记为A1—A9)的米槠林优势种叶片δ13C值的特征及其与属性因子的关系进行分析,结果表明,灵石山米槠林优势种叶片δ13C的分布范围为(-28.806‰—-34.399‰),平均值为(-30.885±1.205)‰,叶... 对灵石山海拔157—842 m(分9个海拔梯度,分别记为A1—A9)的米槠林优势种叶片δ13C值的特征及其与属性因子的关系进行分析,结果表明,灵石山米槠林优势种叶片δ13C的分布范围为(-28.806‰—-34.399‰),平均值为(-30.885±1.205)‰,叶片δ13C值与比叶面积(SLA)、叶片N含量、2年生K含量、Na含量、Mg含量、Ash(灰分)含量呈显著负相关,与2年生叶片Chl(叶绿素)含量、叶片P含量、叶片Ca含量、叶片干物质含量(LDMC)含量呈显著正相关,与不同叶龄Fe、Zn含量相关性不显著,与1年生和2年生叶片Mn含量分别呈负相关和正相关。不同优势种植物叶片δ13C丰度差异可以反映植物生理状况的变化。不同海拔梯度上叶片属性特征在一定程度上反映和影响了以米槠为建群种和优势种的灵石山常绿阔叶林叶片δ13C的特征。 展开更多
关键词 优势种 稳定性碳同位素 叶属性因子 米槠林 灵石山
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树叶属性与林火发生率之间的关系初探 被引量:2
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作者 冯玉元 《森林防火》 2020年第2期29-31,50,共4页
选择在同一地块、坡向、海拔和时间,采摘云南松、华山松、云南油杉、云南杉木、圆柏、龙柏、麻栎、木荷、石楠、枫树、黄连木和云南香樟等12个树种新鲜树叶。通过对新鲜树叶称重和阴干树叶称重,计算得出12种树种含水量及含水率。结合历... 选择在同一地块、坡向、海拔和时间,采摘云南松、华山松、云南油杉、云南杉木、圆柏、龙柏、麻栎、木荷、石楠、枫树、黄连木和云南香樟等12个树种新鲜树叶。通过对新鲜树叶称重和阴干树叶称重,计算得出12种树种含水量及含水率。结合历年林火发生实际情况进行分析研究,重点探讨树叶与林内温度湿度之间关系、树叶属性与林型火灾发生率之间关系以及树叶含水率与林火之间关系。分析表明:阔叶含水量比针叶含水量高,叶片形态具有较强遮挡阳光的作用,因而阔叶林内降温与增湿效果显著,林内温度越低,湿度越大,林火发生率则越低。与此相反,针叶林内降温与增湿作用不明显,林火发生率相对较高。 展开更多
关键词 树种 叶属性 含水率 林火发生率
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长白山常见树种新叶与老叶的光谱特征差异分析
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作者 陈俊杰 于泉洲 +3 位作者 汤庆新 梁天全 姜杰 张宏立 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第8期2372-2380,共9页
揭示新叶与老叶叶片的叶属性及其光谱特征的差异,不仅对于植被生理生态参数的无损监测有重要意义,而且可为林业定量遥感提供更多理论支撑。对长白山8个树种的新叶和老叶叶片进行采样和光谱测量,获取新老叶片的反射率光谱曲线,并进行一... 揭示新叶与老叶叶片的叶属性及其光谱特征的差异,不仅对于植被生理生态参数的无损监测有重要意义,而且可为林业定量遥感提供更多理论支撑。对长白山8个树种的新叶和老叶叶片进行采样和光谱测量,获取新老叶片的反射率光谱曲线,并进行一阶微分变换和光谱指数计算,同时实验测定比叶面积(SLA)、叶含水率、叶氮含量及叶碳含量等叶属性参数。利用方差分析与相关性分析方法,研究不同树种新老叶片在理化性质、光谱特征上的差异,并分析两者的相关性在新老叶之间的差异。结果表明:(1)多个树种的叶属性在新老叶的表现出显著差异。除叶碳含量之外,其他3个叶属性均在多个树种新老叶间表现出显著的差异性,叶碳含量在新老叶间均不存在显著差异。(2)不同树种叶片光谱特征在新老叶间的差异不一致,仅枫桦、裂叶榆、三角槭和红松的新老叶具有较明显的光谱曲线特征差异,枫桦新老叶在光谱三边特征表现出显著差异,尤其是红边。(3)叶属性与光谱信号的相关性在新老叶间表现出显著差异,说明光谱对新老叶叶属性的指示能力不同。近红外光谱反射率对老叶叶氮含量的指示能力强于新叶,而多个光谱指数对新叶含水率和叶碳含量的指示能力强于老叶。研究表明新老叶间不仅叶属性和光谱特征存在差异,而且二者之间的相关性也不同,这对于森林叶属性的无损观测过程中选择代表性叶片具有指导意义。 展开更多
关键词 新老 叶属性 光谱特征 方差分析
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鹿角杜鹃展叶期叶片发育与虫食动态 被引量:10
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作者 刘志国 蔡永立 +1 位作者 李恺 孙灿 《生态环境学报》 CSCD 北大核心 2009年第4期1443-1448,共6页
叶片虫食主要发生在展叶期间,虽然展叶期只是一个短暂的阶段,却可能是了解植食性昆虫和植物之间相互关系的关键。为了解展叶期叶片属性的变化及其与虫食的关系,研究通过野外观察和室内分析,测定福建梅花山亚热带常绿阔叶林中鹿角杜鹃(Rh... 叶片虫食主要发生在展叶期间,虽然展叶期只是一个短暂的阶段,却可能是了解植食性昆虫和植物之间相互关系的关键。为了解展叶期叶片属性的变化及其与虫食的关系,研究通过野外观察和室内分析,测定福建梅花山亚热带常绿阔叶林中鹿角杜鹃(Rhododendron latoucheae)幼树展叶期间叶片属性(叶片氮、可溶性糖、叶绿素含量、含水量、单宁含量、硬度)和叶片虫食率的日变化动态,并分析它们之间的相互关系。结果表明,(1)叶片在爆芽27d后完成展叶,平均展叶率14.06%,(2)可溶性糖、叶绿素和叶片硬度随叶片的展开上升缓慢,在展叶完成几天内后迅速上升;N含量、含水量和单宁含量在展叶期间含量较高,叶片展开后迅速下降。(3)虫食率随着叶片的发育逐渐上升,在第9天达到峰值(0.55%),并在接近展叶完成时迅速下降。(4)叶片虫食率同N含量、含水量、单宁含量正相关,而与叶绿素含量、可溶性糖含量、和叶片硬度负相关。 展开更多
关键词 常绿阔 鹿角杜鹃 叶属性 虫食
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北京山区林地凝结水特征研究 被引量:2
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作者 刘文娜 贾剑波 +1 位作者 涂志华 余新晓 《水土保持通报》 CSCD 2016年第6期298-302,共5页
[目的]研究北京山区林地凝结水的发生情况及分布特征,为该地区的水资源合理利用提供科学依据。[方法]利用首都圈森林生态定位站的大型称重式蒸渗仪对北京山区4种林地的凝结水进行2a连续观测,同时监测林地各项气象因子,分析不同林地凝结... [目的]研究北京山区林地凝结水的发生情况及分布特征,为该地区的水资源合理利用提供科学依据。[方法]利用首都圈森林生态定位站的大型称重式蒸渗仪对北京山区4种林地的凝结水进行2a连续观测,同时监测林地各项气象因子,分析不同林地凝结水的分布特征以及影响因子。[结果](1)北京山区非生长季凝结水出现天数和凝结水量较生长季多,非生长季月平均凝结水量约4.5mm,生长季月平均凝结水量约1.6mm;(2)4种林分年凝结水量大小关系表现为草地(38mm)>栓皮栎(36mm)>油松(30mm)>侧柏(25mm),与年凝结水出现天数大小关系相同,灌草丛是产生凝结水的主要场所,阔叶林产生的凝结水远高于针叶林;(3)空气温度和相对湿度对凝结水的产生起到决定性作用。[结论]北京山区林地凝结水在时间上分布不均,受环境因子和植被因子的综合影响。 展开更多
关键词 凝结水 蒸渗仪 时空分布特征 温度梯度 表面属性
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Genetic Diversity of Indocalamus Determined by Chloroplast DNA Sequence 被引量:1
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作者 牟少华 郄光发 彭镇华 《Agricultural Science & Technology》 CAS 2010年第4期50-52,89,共4页
[Objective]The aim was to research the relationship and genetic diversity of Indocalamus.[Method]Using 13 samples of Indocalamus and 3 samples of Sasa as materials,the intergenic regions of trnL-trnF gene in chloropla... [Objective]The aim was to research the relationship and genetic diversity of Indocalamus.[Method]Using 13 samples of Indocalamus and 3 samples of Sasa as materials,the intergenic regions of trnL-trnF gene in chloroplast were amplified by PCR,and sequence analysis and phylogenetic trees construction were carried out.[Result]Using the universal primer,the intergenic regions of trnL-trnF were amplified,the lengths of the segments varied from 1 008 bp to 1 103 bp,of which 940 bp was compared.The dendrogram of trnL-trnF sequences showed that Indocalamus and Sasa were clustered together and they were homologous by 99%.All the samples were divided into five groups,the first group included 12 samples such as Indosalamus pedalis,I.pumilus,I.victorialis,I.longiauritus,I.tessellatus,Sasa sinica,Sasa pygmaea,I.barbatus,I.guangdongensis,I.herklotsii,I.Hirtivaginatus and S.fortunei.I.decorus,I.lacunosus,I.Latifolius and I.Migoi were respectively divided into four groups.[Conclusion]The high homology of all samples showed the low evolution speed and little information sites which suggested that the phylogeny of Indocalamus could not be well resolved by the intergenic region of trnL-trnF. 展开更多
关键词 INDOCALAMUS Chloroplast DNA SEQUENCE DIVERSITY
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Leaching of nickel-molybdenum sulfide ore in membrane biological reactor 被引量:1
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作者 陈家武 高从堦 +2 位作者 张启修 肖连生 张贵清 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第6期1395-1401,共7页
The bioleaching of molybdenum from its sulfide ore using a Mo-resistant thermophilic bacterium sulfolobus metallics combined with a membrane biological reactor(MBR) was studied.The experimental results showed that t... The bioleaching of molybdenum from its sulfide ore using a Mo-resistant thermophilic bacterium sulfolobus metallics combined with a membrane biological reactor(MBR) was studied.The experimental results showed that the concentration of Mo can be controlled by filter of the membrane in MBR and the toxicity of Mo to microorganism is decreased in the process of bioleaching.It was also evidenced that there were different leaching rates of Ni and Mo when the concentration of Mo was different.After leaching for 20 d in the MBR at Mo concentration of 395 mg/L,the leaching rates of Ni and Mo reached the maximum of 79.57% and 56.23% respectively under the conditions of 100 g/L of mineral density,65 ℃,pH=2 and 1.0 L/min of the aeration rate.While 75.59% Ni and 54.33% Mo were leached out in column without membrane under the same conditions. 展开更多
关键词 membrance biological reactor nickel-molybdenum sulfide ore sulfolobus metallics BIOLEACHING molybdenum toxicity
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Transcriptional,post-transcriptional and post-translational regulations of gene expression during leaf polarity formation 被引量:9
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作者 Lin Xu Li Yang Hai Huang 《Cell Research》 SCIE CAS CSCD 2007年第6期512-519,共8页
Leaf morphogenesis requires the establishment of adaxlal-abaxlal polarity after primordium initiation from the snoot apical meristem (SAM). Several families of transcription factors are known to play critical roles ... Leaf morphogenesis requires the establishment of adaxlal-abaxlal polarity after primordium initiation from the snoot apical meristem (SAM). Several families of transcription factors are known to play critical roles in promoting adaxial or abaxial leaf fate. Recently, post-transcriptional gene silencing pathways have been shown to regulate the establishment of leaf polarity, providing novel and exciting insights into leaf development. For example, microRNAs (miR 165/166) and a trans-acting siRNA (TAS3-derived tasiR-ARF) have been shown to repress the expression of several key transcription factor genes. In addition, yet another level of regulation, post-translational regulation, has been revealed recently by studies on the role of the 26S proteasome in leaf polarity. Although our understanding regarding the molecular mecha- nisms underlying establishment of adaxial-abaxial polarity has greatly improved, there is still much that remains elusive. This review aims to discuss recent progress, as well as the remaining questions, regarding the molecular mechanisms underlying leaf polarity formation. 展开更多
关键词 ARABIDOPSIS leaf development polarity formation
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江苏宝华山主要常绿植物叶寿命与虫食频度相关性 被引量:6
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作者 王瑞雪 张光富 孙晶晶 《生态学杂志》 CAS CSCD 北大核心 2014年第6期1459-1466,共8页
研究叶寿命与叶片虫食相关性对揭示常绿树种的生活史特征及生态适应机制具有重要意义。采用静态生命表和野外观测分析江苏宝华山5个主要树种叶寿命及虫食频度,并对叶属性进行室内测定。结果表明:1)5个树种叶预期寿命不同(P〈0.05),... 研究叶寿命与叶片虫食相关性对揭示常绿树种的生活史特征及生态适应机制具有重要意义。采用静态生命表和野外观测分析江苏宝华山5个主要树种叶寿命及虫食频度,并对叶属性进行室内测定。结果表明:1)5个树种叶预期寿命不同(P〈0.05),介于1.26-2.47 a,平均1.80 a。2)不同树种叶片虫食频度不同,平均为34.74%,且同一树种现存叶片的虫食频度随叶片龄级的增大而增大。3)5种植物的叶寿命和虫食频度存在显著正相关(P〈0.05)。叶片硬度、厚度、含水量和LMA之间存在显著相关性,其主成分分析结果表明:第1主成分贡献率达92.57%,并且虫食频度与第1主成分呈显著负相关(P〈0.05)。因此推测,亚热带常绿、落叶阔叶混交林中不同常绿植物,其叶寿命越长,虫食频度也越高;其虫食作用不仅与物种的多度有关,而且与不同叶属性的综合作用(而非单一叶属性)有密切关系。 展开更多
关键词 寿命 虫食 主成分分析 叶属性 宝华山
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Response of Yield, Yield Components and Fiber Properties of Cotton to Different Application Rates of Nitrogen and Boron
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作者 M. Rashidi M. Seilsepour 《Journal of Environmental Science and Engineering》 2011年第9期1147-1154,共8页
Nitrogen (N) was applied at rates of 0, 100, 200 and 300 kg.ha^-1 and boron (B) was applied as foliar at rates 0, 500 and 1000 g.ha^-1 to study the effect of different application rates of nitrogen and boron ferti... Nitrogen (N) was applied at rates of 0, 100, 200 and 300 kg.ha^-1 and boron (B) was applied as foliar at rates 0, 500 and 1000 g.ha^-1 to study the effect of different application rates of nitrogen and boron fertilizers on yield, yield components and fiber properties of cotton. Statistical results of study showed that N application significantly (P 〈 0.05) enhanced boll number, boll weight, seed cotton weight of boll, seed cotton yield and lint yield. Results of study also indicated that the maximum seed cotton yield was recorded in case of 200 kg.ha^-1 N application rate, and this application rate resulted in 19.6% increased seed cotton yield. Statistical results also indicated that foliar application of B significantly enhanced boll number, boll weight, seed cotton yield and lint yield. Results also demonstrated that the maximum seed cotton yield was obtained in case of 1000 g.hal foliar application of B, and this foliar application rate resulted in 25% increased seed cotton yield. Statistical results showed that effect of different application rates of N was not significant for all fiber properties (fiber length, fiber strength and fiber fineness). Conversely, results of study indicated that different application rates of B significantly affected some fiber properties. 展开更多
关键词 NITROGEN BORON COTTON YIELD yield components fiber properties Iran.
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Comparison of pretreatment,preservation and determination methods for foliar pH of plant samples 被引量:1
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作者 Sining Liu Jiashu Chen Wenxuan Han 《Journal of Plant Ecology》 SCIE CSCD 2022年第4期673-682,共10页
To compare current methods of pretreatment/determination for plant foliar pH,we proposed a method for longperiod sample preservation with little interference with the stability of foliar pH.Four hundred leaf samples f... To compare current methods of pretreatment/determination for plant foliar pH,we proposed a method for longperiod sample preservation with little interference with the stability of foliar pH.Four hundred leaf samples from 20 species were collected and four methods of pH determination were used:refrigerated(stored at 4°C for 4 days),frozen(stored at−16°C for 4 days),oven-dried and fresh green-leaf pH(control).To explore the effects of different leaf:water mixing ratio on the pH determination results,we measured oven-dried green-leaf pH by leaf:water volume ratio of 1:8 and mass ratio of 1:10,and measured frozen senesced-leaf pH by mass ratio of 1:10 and 1:15.The standard major axis regression was used to analyze the relationship and the conversion equation between the measured pH with different methods.Foliar pH of refrigerated and frozen green leaves did not signifcantly differ from that of fresh green-leaf,but drying always overrated fresh green-leaf pH.During the feld sampling,cryopreservation with a portable refrigerator was an advisable choice to get a precise pH.For long-duration feld sampling,freezing was the optimal choice,and refrigeration is the best choice for the shorttime preservation.The different leaf:water mixing ratio signifcantly infuenced the measured foliar pH.High dilution reduced the proton concentration and increased the measured pH.Our fndings provide the conversion relationships between the existing pretreatment and measurement methods,and establish a connection among pH determined by different methods.Our study can facilitate foliar pH measurement,thus contributing to understanding of this interesting plant functional trait. 展开更多
关键词 green/senesced leaf leaf pH plant functional traits sample preservation specifcation/standard/protocol leaf water ratio transformation/conversion equation
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Variation and potential influence factors of foliar pH in land-water ecozones of three small plateau lakes 被引量:1
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作者 Sining Liu Shenqun An +4 位作者 Zhengbing Yan Junpeng Ren Xiaoqian Lu Feiyang Ge Wenxuan Han 《Journal of Plant Ecology》 SCIE CSCD 2021年第3期504-514,共11页
Aims Foliar pH of terrestrial plants,a trait tightly associated with plant physiology and nutrient utilization,varies with plant functional types(PFTs)and environmental changes.However,it is yet unclear about the vari... Aims Foliar pH of terrestrial plants,a trait tightly associated with plant physiology and nutrient utilization,varies with plant functional types(PFTs)and environmental changes.However,it is yet unclear about the variation in foliar pH of aquatic plants,and the difference between aquatic and terrestrial plants.Methods Foliar pH,leaf carbon,nitrogen content of plants along the lakeshore zones and the environmental conditions(water or soil pH,water status)of the corresponding vegetation of three small plateau lakes were investigated,to determine the variation and potential influence factors of foliar pH at both PFT and community levels.Important Findings Foliar pH varied largely among aquatic plants,and across aquatic,helophytic and terrestrial plants.Floating-leaved macrophytes had more acidic foliage(pH=4.21±0.05)than emergent(5.71±0.07)and submerged macrophytes(5.82±0.06).Foliar pH of aquatic herbs(5.43±0.10)was lower than that of helophytic(6.12±0.07)and terrestrial herbs(5.74±0.05).Terrestrial herbs had significantly higher foliar pH than woody plants.The variation in foliar pH across PFTs may be mainly ascribed to leaf structure,light utilization and nutrient characteristics.Consistent with the pattern on PFT level,aquatic communities had more acidic foliage than terrestrial communities,which was mainly shaped by species composition,water status and environmental pH.This study documented the first-time foliar pH of aquatic plants,and comparison of foliar pH among various plant types at a landscape scale.Our results provide bases for further exploration of the underlying mechanism and its ecological significance for wetland ecosystems. 展开更多
关键词 aquatic macrophyte foliar acidity functional trait helophyte waterfront plant community water gradient
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Study of tribological properties of ecofriendly lubricant additives derived from leaf-surface waxes 被引量:4
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作者 XIA YanQiu HU YiChao +1 位作者 FENG Xin MA Teng 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2018年第3期408-416,共9页
Three kinds of leaf-surface waxes are extracted from the leaves of Euonymus japonicas(EJ), Sabina chinensis(SC) and Sabina procumbens(SP) to be tested for their tribological properties. Lubricating oils containing the... Three kinds of leaf-surface waxes are extracted from the leaves of Euonymus japonicas(EJ), Sabina chinensis(SC) and Sabina procumbens(SP) to be tested for their tribological properties. Lubricating oils containing these 3 waxes respectively were analyzed via gas chromatography-mass spectrometer(GC-MS) for their chemical constituents and tested with friction and wear testing machine and time of flight secondary ion mass spectrometry(TOF-SIMS) for the tribological mechanism. It was found that all the tested cuticular wax can reduce the coefficient of friction, and the waxes of SC and EJ can reduce the wear width. The contents of acid and esters in the wax can improve the friction reducing property by forming tribochemical films on the metal, but result in the increase of wear due to corrosion. The increase of ions containing C, H, O and the decline of aluminum positive ions on the worn surface,demonstrate that the tribofilms derived from long chain compounds play a role of protecting the metal surfaces. 展开更多
关键词 leaf-surface wax friction wear lubricant additives ecofriendly lubricant
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Synergistically electronic tuning of metalloid CdSe nanorods for enhanced electrochemical CO_(2) reduction 被引量:4
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作者 Tao Chen Tianyang Liu +8 位作者 Xinyi Shen Wei Zhang Tao Ding Lan Wang Xiaokang Liu Linlin Cao Wenkun Zhu Yafei Li Tao Yao 《Science China Materials》 SCIE EI CAS CSCD 2021年第12期2997-3006,共10页
Engineering the electronic properties of catalysts to target intermediate adsorption energy as well as harvest high selectivity represents a promising strategy to design advanced electrocatalysts for efficient CO_(2) ... Engineering the electronic properties of catalysts to target intermediate adsorption energy as well as harvest high selectivity represents a promising strategy to design advanced electrocatalysts for efficient CO_(2) electroreduction.Herein,a synergistical tuning on the electronic structure of the Cd Se nanorods is proposed for boosting electrochemical reduction of CO_(2) .The synergy of Ag doping coupled with Se vacancies tuned the electronic structure of the CdSe nanorods,which shows the metalloid characterization and thereby the accelerated electron transfer of CO_(2) electroreduction.Operando synchrotron radiation Fourier transform infrared spectroscopy and theoretical simulation revealed that the Ag doping and Se vacancies accelerated the CO_(2) activation process and lowered the energy barrier for the conversion from CO_(2) to;COOH;as a result,the performance of CO_(2) electroreduction was enhanced.The as-obtained metalloid Ag-doped CdSe nanorods exhibited a 2.7-fold increment in current density and 1.9-fold Faradaic efficiency of CO compared with the pristine CdSe nanorod. 展开更多
关键词 cadmium selenium Ag doping Se vacancies CO_(2)electroreduction
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A property of Pisot numbers and Fourier transforms of self-similar measures
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作者 HU Tian-You 《Science China Mathematics》 SCIE 2012年第8期1721-1733,共13页
For any Pisot number β it is known that the set F(β) ={t : limn→∞‖tβn‖ = 0} is countable, where ‖α‖ is the distance between a real number a and the set of integers. In this paper it is proved that every m... For any Pisot number β it is known that the set F(β) ={t : limn→∞‖tβn‖ = 0} is countable, where ‖α‖ is the distance between a real number a and the set of integers. In this paper it is proved that every member in this set is of the form cβn, where n is a nonnegative integer and e is determined by a linear system of equations. Furthermore, for some self-similar measures μ associated with β, the limit at infinity of the Fourier transforms limn→μ(tβn)≠0 if and only if t is in a certain subset of F(β). This generalizes a similar result of Huang and Strichartz. 展开更多
关键词 Bernoulli convolution Fourier transform minimal polynomial Pisot number recurrence relation self-similar measure
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