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黑荆树皮栲胶改性及其鞣革性能研究 总被引：1，自引：0，他引：1
实验室和工厂鞣革试验证明，改性黑荆树栲胶的鞣革性能和成革质量指标与进口荆树栲胶相似，含单宁７０％￣７６％，总颜色３￣６，可代替进口荆树栲胶用于各种皮革制品的鞣制，包括各种浅色、优质皮革制品的生产。 相似文献
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近年,军工、民用的制革者反映,橡椀栲胶用于少浴速鞣中,应努力改进其渗透、结合和抗热性能。提高渗透速度,可以扩大橡椀用量,代替一部分杨梅栲胶;增进抗热性能,可以提高军用革质量。采用化学改性方法,在橡椀栲胶生产过程中,添加适量的氨基苯磺酸(Sulfa-nilic acid),以降低栲胶粘度,增进胶粒分散性,使鞣液透入裸皮速度得到改善。但在鞣制中,随改性栲胶用量的增加,成革的耐潮热稳定性下降。为了既有利于渗透,又有利于抗温和结合,经选用氨基苯磺酸与四硼酸钠混合处理后,收到明显效果。试验证明:在军用水牛肉底革鞣制工艺条件下,证明两种改性橡椀栲胶(5-1,5-2型)的渗透速度和成革耐潮热性比普通橡椀有明显的提高。在水牛肉底革初鞣阶段代替33％杨梅栲胶,可以满足军用水牛肉底革植鞣工艺要求。 相似文献
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植—铝结合鞣法中几种常用国产栲胶的性质 总被引：3，自引：1，他引：2
研究的目的,为了进一步发展国产栲胶在制革工业上的应用,以代替部分或全部铬鞣剂而减少制革工业中铬盐对环境的污染。本文研究了橡椀(水解类),山槐、木麻黄、落叶松(缩合类),杨梅、抽柑(混合类)等常用的6种国产栲胶,在植—铝结合鞣法中所表现的性质。结果表明:①橡椀的结合鞣革,收缩温度最高,但抗张强度最低。落叶松的结合鞣革,收缩温度最低,但抗张强度最高。收缩温度和抗张强度都比较好的为木麻黄,其次为柚柑。杨梅和山槐的结合鞣革,虽然收缩温度较高,但强度低,故实施植—铝结合鞣法,可以选用水麻黄或柚柑,也可采取将落叶松及橡椀,按一定比例混合使用的办法;②植鞣前进行甲醛预处理,可提高结合鞣革的收缩温度;③加脂可提高成革的抗张强度。 相似文献
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毛杨梅栲胶重度亚硫酸化改性与应用研究 总被引：9，自引：0，他引：9
在高温和铝化合物存在下，对毛杨梅（Myrica esculenta)栲胶进行重度亚硫酸化改性，将改性栲胶用作皮革中和剂，研究了影响改性产物性质的一些参数，如缓冲性，中和性能等。得出最佳改性方案，其质量配比为：毛杨梅栲胶100份，NaHSO3 30 份，Na2SO3 36份，含铝化合物1份，在129摄氏度，165kPa下反应10h得到改性栲胶产物。改性栲胶水溶性良好，5％溶液pH值为7．15，10％溶液pH值为7．0，分析表明，其宁含量在20％到30％之间，符合皮革中和复鞣剂的要求，缓冲性实验表明，适量未反应的亚硫酸盐能与改性单宁组成缓冲体系，在pH值3．5－5．5之间具有良好的缓冲性，鞣性实验表明，经亚硫酸盐处理后，毛杨梅栲胶的鞣性显著下降，收敛性缓和，渗透迅速，用量以削匀蓝革计3％－5％为佳，视铬复鞣后pH值而定，1％的用量约可使pH值提高0．3，由于改性栲胶还保留着适当的鞣性和填充性，因此它具有中和与复鞣的双重作用。 相似文献
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漆酚—水杨酸接枝树脂的合成及对金属离子的吸附 总被引：6，自引：0，他引：6
介绍了漆酚－水杨酸接枝树脂的合成方法,用红外和紫外光谱对合成树脂进行了表征,初步研究了ＵＳＲ对多种金属离子的吸附性能,结果显示,ＵＳＲ能与Ａｇ＾＋,ｇ＾２＋,Ｃｕ６２＋,Ｆｅ＾３＋,Ａｌ＾３＋,Ａｉ＾３＋等金属离子络合,ＵＳＲ等用于金属离子的分离,也能作为高分子催化剂和固定化漆树酶的载体。 相似文献
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世界各国栲胶工业目前的主要发展趋势,是选择适当的鞣料植物,大力建立原料基地,使原料供应尽可能单纯、稳定,从根本上提高栲胶的产量和质量,降低生产成本。荆树生长快,树皮单宁含量高,栲胶鞣革性能好,木材坚实,在热带和亚热带地区,栲胶原料基地树种的选择,普遍趋向于发展荆树为主。 相似文献
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橡椀栲胶是我国生产的主要栲胶品种。因其色泽太深不能满足制革工业和出口的要求,近年来各地生产、科研部门对浅化栲胶颜色做了大量的研究工作,采用焦亚硫酸钠、保险粉、吊白块等还原性化学药品处理橡椀栲胶,但效果不甚明显,于1975年我们采用过氧化氢、臭氧等强氧化剂处理像椀栲胶脱色试验,所得产品颜色较浅,总色值10——20％左右,色值稳定,冷溶性好,经鞣革试验成革颜色淡淡,鞣质渗透速度与磺化橡椀栲胶基本相 相似文献
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《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
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《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
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《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
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《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
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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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《Scandinavian Journal of Forest Research》2012,27(2):131-138
The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided. 相似文献
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《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
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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
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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