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密郁闭林分针叶林失叶量遥感监测模型初探 被引量:12
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作者 武红敢 崔恒建 +3 位作者 乔彦友 黄建文 陈林洪 严小君 《国土资源遥感》 CSCD 1995年第2期29-35,共7页
森林资源现状的监测和评估,是环境资源遥感的重要内容之一,它不仅关系着林业的发展,而且直接对区域环境及其可持续发展有着深远的影响,因而,这一问题已引起各国的极大关注。本文主要探讨利用TM数据进行定量监测和评估森林落叶量... 森林资源现状的监测和评估,是环境资源遥感的重要内容之一,它不仅关系着林业的发展,而且直接对区域环境及其可持续发展有着深远的影响,因而,这一问题已引起各国的极大关注。本文主要探讨利用TM数据进行定量监测和评估森林落叶量的可行性,总结出森林植被绿色生物量的变化也可用罗辑斯蒂曲线来描述。 展开更多
关键词 失叶量 遥感监测 森林资源 分针叶林 马尾松
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马尾松毛虫害林分失叶量估测研究 被引量:6
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作者 谢舒菁 李秀平 +3 位作者 刘健 许章华 陈平留 吴群平 《三明学院学报》 2010年第6期558-564,592,共8页
马尾松毛虫是马尾松的主要害虫,发生频繁、危害严重。林分失叶量可直接反映马尾松毛虫危害等级,但实测困难、费力。虫情级数具有预测林分失叶量的能力,据此提出一种间接估测马尾松毛虫害林分失叶量的方法。依据马尾松毛虫害林分失叶量... 马尾松毛虫是马尾松的主要害虫,发生频繁、危害严重。林分失叶量可直接反映马尾松毛虫危害等级,但实测困难、费力。虫情级数具有预测林分失叶量的能力,据此提出一种间接估测马尾松毛虫害林分失叶量的方法。依据马尾松毛虫害林分失叶量与虫情级数的相关关系,以虫情级数作为林分失叶量估测的替代因子,提取5类光谱植被指数(差值植被指数、比值植被指数、归一化差值植被指数、土壤调整植被指数及转换型土壤调整植被指数)和3类地形因子(高程、坡度、坡向),同时运用数量化理论Ⅰ和多元统计回归分析方法对虫情级数进行模拟,确定最优估测方法与影响林分失叶量的主导因子,从而实现马尾松毛虫害林分失叶量与虫害等级的估测。以沙县为实验区,结果表明:(1)数量化理论Ⅰ、多元统计回归分析方法对虫情指数的总体估测精度分别为73.68%、70.10%;(2)影响虫情级数或林分失叶量的主导因子为DVI、坡度、坡向、高程,其中DVI的作用最大;(3)通过替代法,反映了沙县马尾松毛虫害林分失叶量的大致情况,危害程度以轻、中为主,只有极少部分区域灾害较为严重。所提出的间接估测马尾松毛虫害林分失叶量的方法具有可行性。 展开更多
关键词 马尾松毛虫 林分失叶量 虫情级数 沙县 MODIS影像
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失叶量对林木生长的影响与防治
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作者 佟焕明 张学林 《林业月报》 1997年第1期19-19,共1页
关键词 林木生长 失叶量 防治
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利用航天遥感资料监测森林失叶量的可行性研究 被引量:9
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作者 武红敢 黄建文 +2 位作者 乔彦友 陈林洪 严小君 《林业科技通讯》 1994年第7期25-25,共1页
利用航天遥感资料监测森林失叶量的可行性研究武红敢,黄建文,乔彦友,陈林洪,严小君近些年来,由于空气污染导致的酸雨、气候干旱、森林病虫害侵袭等原因引起的森林失叶现象日趋严重,轻者影响材积生长,重者则导致树木死亡,枯朽。... 利用航天遥感资料监测森林失叶量的可行性研究武红敢,黄建文,乔彦友,陈林洪,严小君近些年来,由于空气污染导致的酸雨、气候干旱、森林病虫害侵袭等原因引起的森林失叶现象日趋严重,轻者影响材积生长,重者则导致树木死亡,枯朽。这一问题已引起欧美各国的高度重视。... 展开更多
关键词 航天遥感 森林失叶量 监测
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失叶率对小黑杨和兴安落叶松幼苗生物量和叶绿素含量的影响 被引量:9
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作者 李媛媛 张凯 +1 位作者 李霜雯 严善春 《林业科学》 EI CAS CSCD 北大核心 2015年第3期93-101,共9页
【目的】食叶害虫危害可造成树木失叶,影响树木的生物量及碳储量。研究虫害对杨树及落叶松幼苗生物量和叶绿素含量的影响,可为准确评估食叶害虫不同危害程度对杨树和落叶松碳汇能力的影响提供依据。【方法】选取小黑杨及兴安落叶松幼苗... 【目的】食叶害虫危害可造成树木失叶,影响树木的生物量及碳储量。研究虫害对杨树及落叶松幼苗生物量和叶绿素含量的影响,可为准确评估食叶害虫不同危害程度对杨树和落叶松碳汇能力的影响提供依据。【方法】选取小黑杨及兴安落叶松幼苗,模拟虫害进行剪叶25%,50%和75%处理,以不剪叶植物作为对照。在剪叶处理后第5,10,15,20天和25天取样,分别测定生物量和叶绿素含量的变化。【结果】生物量测定结果表明:各处理对2种幼苗的株高影响不显著(P>0.05),除落叶松失叶50%的根长显著大于对照(P<0.05)外,其他处理幼苗根长无显著变化。各处理的杨树根部鲜、干质量,全株生物量鲜、干质量均显著低于对照,茎鲜、干质量无显著变化。各处理的兴安落叶松根、茎的鲜、干质量及全株生物量鲜、干质量均显著低于对照。叶绿素测定结果表明:杨树叶片中叶绿素a含量高于叶绿素b,各处理组杨树的叶绿素含量均有不同程度的升高。失叶处理后第5天,处理组叶绿素含量比对照组增多,且失叶75%杨树植株叶绿素a和a+b的含量显著高于对照及失叶25%和50%(P<0.05);第10天,失叶率25%,75%处理组叶绿素b和a+b含量显著高于对照(P<0.05),各处理之间差异不显著;第15天,叶绿素含量各个处理组之间、及与对照差异均不显著(P>0.05);处理后20天,失叶50%的植株叶绿素a,b和a+b的含量显著低于对照和失叶25%(P<0.05),亦低于75%,但差异不显著;第25天,各处理叶绿素含量与对照间差异不显著(P>0.05),失叶50%显著高于失叶25%(P<0.05),亦高于失叶75%,但差异不显著。落叶松针叶中叶绿含量素b高于叶绿素a。落叶松叶绿素含量,在失叶量25%和75%处理组,有先升高后降低再升高的趋势,第5天叶绿素含量增加(P<0.05),第10天叶绿素含量降低(P<0.05),第15天与对照相比无差异,第20天叶绿素含量明显升高(P<0.05),到第25天叶绿素含量与对照相近;失叶量50%处理组,第5,15,20天叶绿素含量与对照相比明显降低(P<0.05),且第5天和20天亦显著低于另外2组处理;第10天与对照及另外2组差异不显著(P﹥0.05),到第25天叶绿素含量明显高于对照和其他2组处理(P<0.05)。【结论】失叶对杨树和兴安落叶松的固碳能力和光合生理反应均有影响,杨树和落叶松通过增加叶绿素含量,提高单位面积的光合能力,在一定程度上补偿其固碳能力的降低和生物量的损失,且杨树的补偿能力强于落叶松。 展开更多
关键词 兴安落叶松 小黑杨 失叶量 生物量 叶绿素
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失叶对油松光合强度叶绿素含量和蒸腾强度的影响
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作者 李向军 《河北林业科技》 北大核心 1993年第4期24-26,共3页
用人工摘叶方法模拟松毛虫的取食,测定不同失叶量对油松光合强度、叶绿素含量及蒸腾强度的影响。结果表明,轻度失叶(30%左右)针叶的光合强度及蒸腾强度较不失叶为高;随着失叶量的增加,光合强度、叶绿素含量、蒸腾强度逐渐下降。
关键词 失叶量 光合强度 叶绿 油松
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鞭角华扁叶蜂发生量的预测 被引量:1
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作者 陈绘画 郑永祥 杨胜利 《浙江林业科技》 2001年第2期32-35,共4页
在系统地研究柏木鲜叶量、鞭角华扁叶蜂幼虫种群食叶量及各虫态种群数量幼态变动的基础上,利用柏木的失叶量估计鞭角华扁叶蜂入土老熟幼虫虫口密度,进而预测来年的发生量,结果表明:利用柏木失叶量预测发生量,预测准确率达 90%。
关键词 鞭角华扁叶蜂 发生量 预测 森林害虫 失叶量 滞育幼虫 虫口密度
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Wheat Yield Response to Foliar Fungicide Application against Leaf Rust Caused by Puccinia triticina
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作者 Krishna Dev Joshi Ghulam Ullah +6 位作者 Attiq Ur Rehman Muhammad Makky Javaid Javed Ahmad Makhdoom Hussain Angela Pacheco Ibni Amin Khalil Amanullah Baloch 《Journal of Agricultural Science and Technology(A)》 2017年第3期160-168,共9页
A study was conducted on reducing the yield loss of wheat due to leaf rust caused by Puccinia triticina with foliar application of fungicides during the 2014-2015 and 2015-2016 growing seasons at the Wheat Research In... A study was conducted on reducing the yield loss of wheat due to leaf rust caused by Puccinia triticina with foliar application of fungicides during the 2014-2015 and 2015-2016 growing seasons at the Wheat Research Institute in Faisalabad, Pakistan. Three fungicides: Folicur (tebuconazole) at 300 mL/ha, Nativo (tebuconazole + trifloxystrobin) at 300 g/ha and Tilt (propiconazole) at 500 mL/ha were applied single or two times to Morocco and Sehar-06 wheat varieties used in the trial. The trial plots were first sprayed at the Zadok's scale (ZS) 3 stage and second sprayed between ZS 4.3 and 5.4 stages. The greenness of the trial crop was measured using GreenSeeker. Foliar application of fungicides significantly reduced the loss of grain yield and 1,000-grain weight (TGW) of wheat due to leaf rust in comparison to the control without fungicides application. Of the three fungicides, two times spray of Nativo reduced the grain yield loss of leaf rust susceptible mega wheat variety Sehar-06 by 45%-56% and the loss of TGW by 42%, also giving the highest marginal return in the trial. Single application of Nativo was equally effective as two times spray of Folicur in reducing the loss of wheat grain yield. Two times spray of Folicur was found to be the second choice of fungicide for reducing the yield loss of wheat. The research identified suitable fungicides for reducing the yield loss of wheat due to leaf rust and also generated important scientific knowledge required to manage a sudden outbreak of leaf rust to ensure food security. 展开更多
关键词 Wheat variety leaf rust yield loss yield response foliar spray of fungicide resistance breeding.
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The Relationship between Diseases Index of Septoria Leaf Blotch, Leaf Rust and Yield Losses in Bread Wheat Cultivar in Albania
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作者 Vrapi Hekuran Gixhari Belul +2 位作者 Kashta Foto Sulovari Halit Ruci Thanas 《Journal of Environmental Science and Engineering(B)》 2012年第8期957-965,共9页
Both grain yield and disease performance are important factors to consider for winter wheat (Triticum aestivum) cultivar selection. However, disease index and yield data are often presented separately, making it dif... Both grain yield and disease performance are important factors to consider for winter wheat (Triticum aestivum) cultivar selection. However, disease index and yield data are often presented separately, making it difficult to compare values across multiple environments. Two-year investigations (2009-2010), in which eight common wheat lines/genotypes were included to test their susceptibility against wheat LR (leaf rust) Puccinia triticina f. sp. tritici Roberge ex Desm., and the SLB (SeptoriaJStagonospora leaf blotch) complex Septoria tritici Desm. and Stagonospora nodorum, were carried out in the experimental field of ATTC (Agriculture Technology Transfer Centre) of Lushnje (Albania). The objective of this study was to use a rank-based method to compare cultivars based on yield and disease performance combined across multiple environments. Analysis of variance revealed the presence of an important and significant variability in the experimental materials used to evaluate the susceptibility and the resistance of common wheat lines against SLB and LR. There were high negative correlations between yieldS, tritici (0.6683) and yield--P, recondita f. sp. tritici (0.5261). The negative effects of two pathogens have shown "the parallel"/similar negative influences on yield trait and there was a high positive correlation (0.7631) between S. tritici and P. recondita f. sp. tritici. According to study results the lines Regina × L-776, IKB-P6 and Bullgar 3 × KB 703 have shown good results of resistance (R) level against S. tritici and P. recondita f. sp. tritici. 展开更多
关键词 WHEAT disease index leaf rusl Septoria tritici blotch.
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Effects of Airfoil-probe Tubes on the Flow Field of a Compressor Cascade 被引量:5
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作者 MA Hongwei JIN Chao +1 位作者 ZHAO Lianpeng MA Rong 《Journal of Thermal Science》 SCIE EI CAS CSCD 2017年第4期321-330,共10页
To explore the effects of airfoil-probe tubes and its installment position on the flow field of the compressor cas- cade, and find out the mechanism that how the airfoil-probes affect the aerodynamic characteristics o... To explore the effects of airfoil-probe tubes and its installment position on the flow field of the compressor cas- cade, and find out the mechanism that how the airfoil-probes affect the aerodynamic characteristics of the com- pressor cascade, this paper performed both numerical and experimcntal works on the same compressor cascade. The experiment mainly focused on the cases of low Mach number (Ma = 0.1), and cases with different Mach numbers (0.1, 0.3, 0.7) and different incidence angles (-5, 0, 5) are investigated by the numerical method. The case without the airfoil-probe tube was referenced as the baseline, and other three cases with the airfoil-probe tubes installed in different chordwise positions O0%, 50%, 70% of the chord length) were studied. The diameter of the airfoil-probe tube is 3ram, which is configured as 300% amplification of some particular airfoil-probe ac- cording to the geometrical similarity principle. The results show that the airfoil-probe tubes have a negative in- fluenc~ on the flow capacity of the cascade at all investigation points. The separations and the large scale stream- wise vortices that induced by the airfoil-probe tube on the pressure side cause most the losses at the high Mach number. The influence of the airfoil-probe tube on the flow field in the vicinity of the pressure side surface is lo- cal separation at the low Mach number. The airfoil-probe tubes also have a clearly effect on the leakage flow. It decreases the mass flow of the leakage flow and weakens the intensity of the leakage vortex, but enlarges the in- fluence area. The total pressure loss of the case that the tube is installed at the half chordwise position is generally lower than other cases especially at the high Mach number, it can even decrease the losses compared with the ba- sic case. 展开更多
关键词 airfoil-probe compressor cascade installment position 5-hole probe
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Correction of leaf nutrient resorption efficiency on the mass basis 被引量:1
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作者 Meixia Zhang Yan Luo +1 位作者 Qingquan Meng Wenxuan Han 《Journal of Plant Ecology》 SCIE CSCD 2022年第6期1125-1132,共8页
Nutrient resorption is a crucial mechanism for plant nutrient conservation,but most previous studies did not consider the leaf-mass loss during senescence due to lack of measured data.This would lead to an underestima... Nutrient resorption is a crucial mechanism for plant nutrient conservation,but most previous studies did not consider the leaf-mass loss during senescence due to lack of measured data.This would lead to an underestimation of nutrient resorption efficiency(NuRE),or calculating NuRE of various species based on the average mass loss at plant-functional-group level in the literature,thus affecting its accuracy.Here we measured the leaf-mass loss to correct NuRE with the species-specific mass loss correction factor(MLCF),so as to foster a more accurate calculation of the nutrient fluxes within and between plants and the soil.Green leaves and senesced leaves were collected from 35 dominant woody plants in northern China.Mass of green and senesced leaves were measured to calculate the MLCF at species level.The MLCF was reported for each of the 35 dominant woody plants in northern China.These species averagely lost 17%of the green-leaf mass during leaf senescence,but varied greatly from 1.3%to 36.8%mass loss across the 35 species,or 11.7%to 19.6%loss across the functional types.Accordingly,the MLCF varied from 0.632 to 0.987 across the 35 species with an average value 0.832.The NuRE corrected with MLCF was remarkably increased on the whole(e.g.both the average nitrogen and phosphorus NuRE became about 9%higher,or more accurate),compared with the uncorrected ones,especially in the case of low resorption efficiencies.Our field data provide reliable references for the MLCF of plants in related regions at both species and functional-type levels,and are expected to promote more accurate calculations of NuRE. 展开更多
关键词 green leaf leaf litter mass loss correction factor nutrient resorption senesced leaf woody plants
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Deletion of a Dna K protein gene causes seedling green-revertible albino by retarding chloroplast development in rice 被引量:1
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作者 Weitao Li Junjie Yin +14 位作者 Bangquan Ye Chunfang Peng Qinshu Cheng Jing Wang Can Yuan Heng Yin Zhixiong Chen Min He Yuping Wang Weilan Chen Jichun Wang Bingtian Ma Peng Qin Shigui Li Xuewei Chen 《Science Bulletin》 SCIE EI CAS CSCD 2015年第23期2054-2058,共5页
Green-revertible albino mutants are important sources for studying chloroplast structure, chloroplast development, chlorophyll biosynthesis, and plant photo- synthesis. In the present study, we characterized a green- ... Green-revertible albino mutants are important sources for studying chloroplast structure, chloroplast development, chlorophyll biosynthesis, and plant photo- synthesis. In the present study, we characterized a green- revertible albino mutant gra(k), which was obtained from the tissue-cultured rice Kitaake. The mutant gra(k) exhib- ited albino on its first three leaves. The leaf color started to turn green at the four-leaf stage. The chlorophyll contents were deeply reduced at the seedling stage, and the chloroplast development was delayed in gra(k). The green- revertible albino (gra) phenotype of the mutant gra(k) was temperature dependent. The main agronomic traits, including plant height, tilling number per plant, seed set- ting rate, and thousand-grain weight, slightly decreased in gra(k) comparing to those in the wild-type Kitaake. Genetic analysis showed that the gra phenotype was con- trolled by a single recessive nucleic gene. By using 5,168 recessive F2 individuals derived from the cross of gra(k) × Jodan, the locus of the gene Gra(k) was delimited in a DNA region of 200 kb between the makers B-31 and P11 on chromosome 5. Sequencing analysis indicated that the three functionally annotated genes, LOC_Os05g23700, LOC_Os05g23720, and LOC_Os05g23740, were all deleted in the 200 kb region in the mutant gra(k). Trans- genic test revealed that the gra(k) plants over-expressing LOC_Os05g23740CDS were restored to normal green as the wild-type Kitaake. Our results proved that the deletion of the DnaK protein gene LOC_Os05g23740 (encoding the chaperon protein OsHsp70CP1) led to the gra phenotype in the mutant gra(k). 展开更多
关键词 RICE Green-revertible albino Agronomic character - Chlorophyll content Finemapping
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Distortion behavior of hydro turbine blade castings during heat treatment processes under variation of seasonal temperature
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作者 YU HaiLiang KANG JinWu HUANG TianYou 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第1期81-87,共7页
Distortion often appears at the corners of heavy turbine blade castings during heat treatment processes, so a great machining allowance is generally set in production which directly results in cost increase. In this p... Distortion often appears at the corners of heavy turbine blade castings during heat treatment processes, so a great machining allowance is generally set in production which directly results in cost increase. In this paper, a novel real-time measuring technology is developed for non-contact measuring the deformation behavior of heavy steel castings in heat treatment process. It was employed to measure the distortion and the temperature field of a batch of heavy turbine blade castings at cooling stage in normalizing process. Three inflection points appear in the distortion-time curves, and the residual distortion is affected by the regional area of not finished martensite transformation when the second inflection point appears. When the mean air temperature falls into the range of 10℃-20℃, the residual distortion is small; when it is lower than 10℃, positive distortion appears; when it is higher than 20℃, negative distortion appears. The distortion varies with seasonal temperature, which is directly responsible for the great machining allowance given in production. 展开更多
关键词 hydro turbine blade casting distortion behavior heat treatment seasonal temperature variation
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