共查询到20条相似文献，搜索用时 125 毫秒
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土壤有机质测定方法比对分析 总被引：1，自引：0，他引：1
土壤有机质（OM）测定中普遍采用方法有重铬酸钾（K2Cr2O7）容量法、干烧法（测定CO2）、灼烧法等。通过对不同测定方法进行研究比对，分析各种方法的优劣。研究表明：当前我国测定土壤有机质的国家标准方法为重铬酸钾容量法，该方法在测定操作时，数据结果准确，但费时费力，容易产生误差。干烧法可获得比较准确的结果，但该法运行成本高。灼烧法快速、简便，适于大批量土样的分析，但其应用领域受到限制。比对测定土壤有机质常用方法对于明确各法优劣，保证测定准确性具有现实意义。 相似文献
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采用连续流动分析法和亚甲基蓝分光光度法分别测定水中硫化物,并进行了比对试验,结果显示:连续流动分析法测定单个样品时间短,结果准确度和精密度高,对环境友好,是一种快速简便测定水中硫化物的方法。 相似文献
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《内蒙古林业调查设计》2021,44(2)
文章对泰国清迈蘑菇属真菌进行rDNA ITS区段序列测定和序列特征比较分析,并基于ITS序列进行核酸数据库GenBank同源性检索比对,最终构建系统发育树,旨在为从分子水平上探讨蘑菇属真菌的系统发育、亲缘关系和遗传多样性提供参考。 相似文献
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Now,thereisagreatlargeareaoflarchplantationinNortheastofChina.Withtheincreasingofthestandage,competitionsamongtreeindividualschangefromexploitationcompetitiontointerferencecompetitions-Inordertofullyutilizetheresourceofsoilandclimate,effectivetechniquesshou1dbetakentoregulatetherelationshipoftreeindividuals,So,thestabilityandbioproductivityaswellaseconomicbenefitcanbeincaersed.CHARACTERSOFSTANDThestandisdahurianlarchplantati-onthatwasplantedinthespringofl958.Thesiteisabandonedfarmlandw… 相似文献
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根据当前我国木材工业除尘系统的风机应用现状,分析造成其高能耗的原因,通过比较常用的几种调节方法,结论是采用变频调速方法的风机节能效果最佳. 相似文献
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长林3号等油茶品种引种栽培试验初报 总被引：3，自引：0，他引：3
从亚林所引种长林3号、4号等5个油茶新品种,栽培6年后,单株产量2.51～4.87kg,比对照提高58.8%～208.2%,且品种间差异显著;冠幅产量1.71%～2.48kg/m2,比对照提高14.0%～65.3%;666.7m2平均产油17.56～34.88kg,比对照提高了114.9%～326.9%。引种的品种与原产地相比,各项经济指标变化不大。长林3号、4号等油茶品种适应性强、丰产稳产、产油高、抗性强,是适合湖北省推广的优良品种。 相似文献
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A new type of sampler for dry deposition in a forest canopy was designed and tested to confirm its usefulness. The new sampler
is made of Teflon chips packed in a nylon net, and tied on a rod like a branch in the canopy. The validity and characteristics
of the new sampler were checked by comparing it with the conventional bucket sampler and the foliar extraction method using
hinoki (Chamaecyparis obtusa) trees. The comparison between the deposited amounts on the dummy branch and those on the bucket indicates that the dummy
could trap gaseous matter more effective than the bucket. From a comparison with the foliar extracting method, it is concluded
that the trapping of particulate matter by the new dummy branch is comparable to that of natural needle leaves. However, its
efficiency for gaseous matter is relatively small. This disadvantage should be improved by applying other materials to the
dummy. Moreover, it is found that the uptake of gas especially SO2 through the stomata is an important point in the discussion about dry deposition. To evaluate the amounts of dry deposition
in the forest canopy more precisely, combination with the additional method should be useful.
This study was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science, Sports,
and Culture, Japan. 相似文献
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手持GPS和罗盘仪在涉案林地面积测量中的精度分析 总被引：3，自引：0，他引：3
通过在南京中山陵风景区不同林地条件下及南京森林公安学校校园内选设的多个点进行面积测量,以全站仪测量结果为真值,对比分析手持GPS和罗盘仪在林地面积测量中的精度问题,为森林公安人员在办理森林案件中测算林地面积提供参考。 相似文献
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苏喜富 《内蒙古林业调查设计》2000,23(3):32-34
文章通过对项目方案比较中计算期不同的比较方法、标准的选用、经济评价指标的应用进行了具体的分析 ,为项目可行性提供了科学决策方法和依据 相似文献
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以偏关县退耕还林地为研究对象,应用生态学原理和方法,调查退耕还林地的植物种类。结果表明,偏关县退耕地植物共有34科,77属,95种。2000年,2001年和2002年退耕地的植物高度分别比对照区增加了19．8cm,16．2em,7．0cm;植被相对盖度分别增加了47．6％,42．4％和33．1％．退耕地的植物生长发育速度比对照区快。 相似文献
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Potassium phosphite (PP) formulations registered as fertilizers are now prohibited in Spain. Therefore, we evaluated the systemic fungicide fosetyl‐aluminium (fos‐al) in comparison with PP, against root rot caused by Phytophthora cinnamomi in Quercus woodlands. The direct effect of both systemic fungicides was evaluated in vitro on P. cinnamomi mycelial growth. Protection of cork and holm oak against infection was also evaluated in planta. Metalaxyl was included in both in vitro and in planta experiments for comparison purposes. At 100 μg/mL, PP totally inhibited colony radial growth, in comparison with 75% achieved by fos‐al. At doses recommended by manufacturers, with fos‐al and metalaxyl applications, root symptoms remained similar to the uninfected control levels. Based on these results, fos‐al is a candidate substitute product for PP in Quercus woodlands for control of Phytophthora oak root disease. 相似文献