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1.
金竹叶提取物的缓蚀性能研究 总被引：2，自引：2，他引：0
用失重法、动电位极化曲线、电化学阻抗谱(EIS)和原子力显微镜(AFM)研究了20℃时天然植物金竹叶提取物(PSLE)在1.0 mol/L HCl溶液中对冷轧钢的缓蚀作用,并用吸附观点探讨了缓蚀作用机理。结果表明:PSLE对冷轧钢具有良好的缓蚀作用,质量浓度为100 mg/L时缓蚀率高达94.2%。PSLE通过含O、N的极性官能团,在钢表面发生吸附起到缓蚀作用,且吸附规律符合Langmuir吸附等温式。极化曲线表明,PSLE为混合抑制型缓蚀剂;其EIS谱呈半圆容抗弧,电荷转移电阻随缓蚀剂质量浓度(c)的增加而增大。AFM表明PSLE在钢表面吸附形成了致密的缓蚀剂膜层。 相似文献
2.
木麻黄树皮提取物的清除羟自由基活性 总被引：2，自引：0，他引：2
考察了4种木麻黄树皮水提取物的化学组成及其对绝对分子质量分布的影响因素,用邻二氮菲-Fe2+氧化法测定了不同树种和不同溶剂提取物对羟自由基的清除率.结果表明,不同提取溶剂对木麻黄树皮提取物组成、绝对分子质量分布影响较大.盐酸-丙酮-水溶液(HAW,1.0%盐酸与丙酮溶液质量比7∶3)作提取溶剂可大幅提高提取物的总固形物和多酚含量.应用激光散射-凝胶渗透色谱(SEC)技术测得山地木麻黄树皮HAW提取物的绝对分子质量为5×102～2×105.木麻黄提取物清除羟自由基的活性高,质量浓度为2g/L的山地木麻黄树皮HAW提取物对羟自由基的清除率高达81.6%.提取物的组成影响其清除羟自由基活性. 相似文献
3.
通过红外光谱(FT-IR)分析,表征了金竹竹叶提取物(PSLE)的主要官能团,利用失重法、电化学阻抗谱研究了PSLE在1.0 mol/L (')HCl介质中对铝的缓蚀作用.结果表明,PSLE具有较好的缓蚀作用,最大缓蚀率达77.7％,竹叶提取物的缓蚀率在20和30℃时效果较好,在铝表面的吸附符合Langmuir吸附校正模型,通过Van't Hoff方程求出吸附热(△Hads),讨论了缓蚀作用机理,吸附过程是一个自发放热的过程.通过电化学阻抗谱,表明缓蚀剂在铝表面发生吸附后使电荷传递明显抑制,PSLE为混合抑制型缓蚀剂. 相似文献
4.
《浙江林业科技》2015,(5)
以银杏(Ginkgo biloba)外种皮提取物(提取物)不同浓度溶液作为木材防霉防腐剂,对木材上常见的8种霉变菌进行培养基抑菌试验,并对枫香树(Liquidambar formosana)木材的防腐效果进行了测定。结果表明,0.5 g/L浓度的提取物对8种霉菌均有不同程度的抑制效果,其中对杂色曲霉、绵皮卧孔菌、黑曲霉、黄曲霉、彩绒革盖菌的抑制效果与硼酸相当,对可可球二孢抑制效果优于硼酸;提取物浓度1.0 g/L时,对鲜绿青霉的抑制效果与硼酸相当;提取物浓度2.0 g/L时,对绿色木霉的抑制效果与硼酸相当;当提取物浸渍液浓度1.0 g/L以上、吸药量0.23 g/m~2以上时,提取物溶液冷浸处理的枫木防腐等级可达I级。 相似文献
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6.
核桃叶中抗植物病毒活性物质提取条件的研究 总被引：10，自引：0，他引：10
以不同溶剂和方法对核桃叶进行了抗植物病毒物质的提取和活性测定.结果表明:提取物的抗病毒活性因提取溶剂和提取方法的不同而异.以体积分数 95 % 乙醇为提取溶剂,冷浸提取物在质量浓度 10 g/L 时,对烟草花叶病毒(TMV) 的抑制率最高,为 100 %.采用冷浸提取时,核桃叶中抗TMV活性物质提取的优化条件是:以体积分数 95 % 乙醇为提取溶剂,料液比1:10(g:mL),提取 18 h,得率 21.42 %.质量浓度 5 g/L 的提取物对TMV侵染心叶烟的抑制率为 100 %.该提取物的乙酸乙酯萃取物经多次层析分离和纯化得到黄酮类化合物A,质量浓度 0.5 g/L 的化合物A对TMV侵染心叶烟的抑制率达 85.55 %,说明化合物A是乙酸乙酯萃取物中的主要抗病毒活性成分之一. 相似文献
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8.
瑞香的叶提取物对月季长管蚜有较强毒杀作用。用水提醇沉法和醇提水沉法获得的提取物对蚜虫的致死中浓度(LC50)3963mg/L和6397mg/L。水提醇沉提取物的乙酸乙酯萃取物对月季长管蚜的毒力较其它萃取物强,其LC50为1953mg/L,结果表明:瑞香叶含有杀虫活性物质主要存在于乙酸乙酯萃取物中。对水提醇沉提取物进行硅藻土柱层析分离,得到的第三组分得率和灭蚜效果均优于氧化铝柱层析离到的第三组分。 相似文献
9.
采用失重法及扫描电镜法研究了2-(3'-羟基苯基)-4,5-二(2’羟基苯基)咪唑(HHIP)在1MHCl溶液中对低碳铜的缓蚀作用,并对其缓蚀机理进行了探讨.研究结果表明:在1M HC1溶液中,该缓蚀剂对低碳钢的缓蚀效率可达到90％以上,最佳缓蚀效率达到95.12％,当缓蚀剂浓度为1mmol/L、实验温度为30℃,吸附成膜时间4h,缓蚀效率达最大值,此后基本不变.通过理论计算和分析该缓蚀剂在低碳铜的表面的吸附符合Langmuir吸附,且吉布斯自由能显示为自发过程. 相似文献
10.
以怀槐的心材和树皮为原料,用乙醚、氯仿、丙酮、甲醇和水5种溶剂对其进行浸提,得到10种提取物.这10种提取物对白腐菌和褐腐菌的抑菌性能研究表明,怀槐心材的甲醇和丙酮提取物的抑菌性能良好.将心材的甲醇提取物和无机木材防腐剂酸性铬酸铜(ACC)用于对木材的室内防腐实验,根据腐朽后试样的失重率和扫描电子显微镜(SEM)的照片观测,得出甲醇提取物对白腐菌的防腐作用较好,对褐腐菌的防腐作用很弱,而ACC对两种菌的防腐作用较强.将心材甲醇提取物和ACC用于对斑马鱼的急性毒性试验,测得两者在24、48和 72 h 的半致死浓度,甲醇提取物分别为16.5、12.7、12.0 mg/L,ACC分别为3.2、2.5、2.0 mg/L;两者的安全质量浓度分别为2.26和 0.46 mg/L. 相似文献
11.
《Scandinavian Journal of Forest Research》2012,27(5):427-435
In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads. 相似文献
12.
《Scandinavian Journal of Forest Research》2012,27(3):206-217
The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage. 相似文献
13.
《Scandinavian Journal of Forest Research》2012,27(1):53-61
This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland. 相似文献
14.
《Scandinavian Journal of Forest Research》2012,27(1):15-27
The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions. 相似文献
15.
本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。 相似文献
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17.
《Scandinavian Journal of Forest Research》2012,27(5):472-479
Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken. 相似文献
18.
Srisuda Thippayarugs Banyong Toomsan Patma Vityakon Viriya Limpinuntana Aran Patanothai Georg Cadisch 《Agroforestry Systems》2008,72(2):137-148
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic
or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts
(stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea
(Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content
as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest
N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized
to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea,
largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for
N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant
components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N
released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures
were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality
components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in
the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols.
Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest
age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its
components are mixed. 相似文献
19.
A. Rigueiro-Rodríguez M. R. Mosquera-Losada E. Gatica-Trabanini 《Agroforestry Systems》2000,48(3):245-256
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste
disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization,
(2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two
pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea
(Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect
on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage
sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but
affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral
systems.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
20.
《Scandinavian Journal of Forest Research》2012,27(2):166-178
This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes. 相似文献