萜烯树脂乳液在水基复膜胶中的应用

用乙烯-醋酸乙烯共聚物(EVA)乳液、萜烯树脂乳液和阳离子型苯乙烯-丙烯酰胺共聚物研制了系列水基复膜胶,并考察了萜烯树脂乳液中乳化剂结构对复膜胶性能的影响。研究结果表明,作为交联剂的阳离子型苯乙烯-丙烯酰胺共聚物可大幅提高EVA乳液的黏度和剥离强度,其最佳加入量为0.5%(以EVA乳液的固形物为基准)。萜烯树脂乳液与EVA乳液的质量比值为0.3时,复膜胶的剥离强度最大。由高分子表面活性剂(HS-2)制得的萜烯树脂乳液增加复膜胶剥离强度的效果最好。     

纤维板防水剂用石蜡-松香乳液的组成及其性能研究

采用专用高分子表面活性剂和转相法制备了系列石蜡-松香乳液,并考察了这些乳液中的表面活性剂种类和石蜡与松香的质量比对中密度纤维板防水性和力学性能的影响。研究结果表明,用苯乙烯和丙烯酸及其衍生物为单体的高分子表面活性剂(HS)和烷基苯聚氧化乙烯醚衍生物的低分子表面活性剂(LS)的混合物能制得稳定的石蜡-松香乳液。表面活性剂用量为5kg／m^3时石蜡-松香(质量比1：2)乳液使纤维板的吸水厚度膨胀率减少23．8％,而弹性模量增加了12．2％。表面活性剂的组成和石蜡与松香的质量比都显著地影响乳液的性能和使用效果。     

连接基性质对松香基季铵盐Gemini表面活性剂的活性影响

以四甲基乙二胺及三乙烯二胺为连接基制备了两种松香基季铵盐Gemini表面活性剂Ⅰ与Ⅱ,经表面活性分析:Ⅰ与Ⅱ的CMC值分别为1.42×10-4、9.7×10-4 mol/L,γCMC为36.69、43.41 mN/m;乳化时间为16、10 min;降低表面张力的效率(pc20)计算值为4.2、3.2;HLB计算值皆约为14.45;Ⅰ与阴离子相溶性好,Ⅱ与阴离子相溶性较差.由实验分析结果探讨了连接基性质对松香基季铵盐Gemini表面活性剂的影响,结果表明:以柔性链为连接基的松香基季铵盐Gemini表面活性剂Ⅰ的活性优于以刚性链为连接基的松香基季铵盐Gemini表面活性剂Ⅱ.     

微波合成氢化松香基季铵盐表面活性剂及其性能

以氢化松香、环氧氯丙烷和三乙胺为原料,采用微波辐射法合成氢化松香基季铵盐表面活性剂.通过单因素试验研究了反应条件对酯化率的影响,并对合成产物进行结构确认及其表面性能测定.结果表明,微波辐射法合成氢化松香基季铵盐适宜反应条件为:反应时间75 min,微波功率500 W,反应温度80℃,反应物料配比1∶1∶1(物质的量比),产物酯化率为99.66％,阳离子表面活性物质量分数为82.24％.产物的临界胶束浓度(CMC)为9.83 × 10-4 mol/L,表面张力为35.7 mN/m,乳化力为20 min,泡沫力为225 mm,泡沫稳定性为175 mm,Krafft点＜0℃,亲水亲油平衡值(HLB值)为20.9.微波辐射法与常规加热法相比,反应时间比常规加热法缩短105 min.     

聚萜烯马来酸酐聚乙二醇酯高分子表面活性剂的制备及性能研究

以双戊烯为原料,经催化异构及D-A加成合成了萜烯马来酸酐,萜烯马来酸酐再分别与不同分子质量的聚乙二醇(400,600,1 000,2 000,4 000)反应,合成了5种聚萜烯马来酸酐聚乙二醇酯高分子表面活性剂(Ⅰ~Ⅴ),用红外光谱仪和凝胶色谱仪对产物的结构进行了表征,并对其聚合度(DP)、临界胶束浓度(CMC),表面张力(γ_(CMC)),乳化性能(EP),泡沫性能(FP)和亲水亲油平衡值(HLB)等表面活性性能进行了研究。结果表明:产物Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ的CMC值分别为6.5、2.1、2.7、3.3和5.5 g/L,γ_(CMC)分别为42.0、38.2、39.8、42.1和33.7 m N/m。随着聚乙二醇分子质量的增大,CMC及γ_(CMC)均呈现先减小后增大的趋势;DP先增大后减小,产物Ⅱ聚合度最大,为4.9;EP逐渐降低,产物Ⅰ乳化性能最好,达到780 s;HLB逐渐增大,亲水性增强。     

乳化石蜡/硅烷木材防水剂的制备及性能

为确定石蜡/硅烷木材防水剂的制备工艺,采用正交试验法,考察硅烷直链烷基链长、石蜡/硅烷比例、表面活性剂HLB值和含量四个因素对防水剂稳定性和粒径的影响,并探究不同配比石蜡/硅烷防水剂处理样的防水效果。结果表明,表面活性剂用量6%、HLB值为13.5,配制石蜡/硅烷为2∶1的石蜡/十二烷基甲氧基硅烷乳液,乳液平均粒径195.7 nm,稳定性等级达到1级,用于木材试样疏水改性的384 h防水效率达27.3%。     

相反转乳化法制备萜烯酯型环氧树脂乳液的研究

以自制的聚乙二醇改性萜烯酯型环氧树脂(TP)为乳化剂,采用相反转法乳化萜烯酯型环氧树脂制备了环氧树脂水乳液,分析了乳化过程中体系电导率变化与微观形态转变的关系,讨论了乳化剂质量分数、乳化温度、搅拌速度、乳液固含量等条件对乳液粒子体积平均粒径(D[4,3])及粒径分布一致性、黏度、离心稳定性、环氧值及环氧保留率等乳液性质的影响.实验结果表明,该环氧树脂乳液的最佳制备条件为:TP质量分数16.7%,乳化温度60℃,机械搅拌速度500-900 r/min,固含量约45%.在该条件下制备的乳液性质最好,乳液粒子体积平均粒径约200 nm,粒径分布100-440 nm,黏度850 mPa·s,环氧值0.11 mol/100 g.     

松香酯羟丙基季铵盐表面活性剂的合成、表征及性能

以脱氢枞酸、丙烯海松酸、马来海松酸为原料分别与2,3-环氧丙基三甲基氯化铵反应,得到单、双、三季铵盐Ⅰ、Ⅱ及Ⅲ3种松香酯羟丙基季铵盐表面活性剂。采用IR,1H NMR,13C NMR对产物结构进行了表征,并对产物的临界胶束浓度(Ccmc)、表面张力(γcmc)、乳化性能、泡沫性能及抑菌性能进行了研究。结果表明,3种松香酯羟丙基季铵盐表面活性剂的Ccmc值分别为3.58×10-4、2.53×10-4和3.25×10-4mol/L,对应的γcmc分别为38.9、28.9、33.5 m N/m;乳化时间分别为31、33、38 min;表面活性剂Ⅰ的起泡性较好,起泡高度达到115 mm、5 min后泡沫高度为85 mm;随着季铵盐数量的增加,亲水亲油平衡值(HLB)增大,表面活性剂的亲水性增强;季铵盐Ⅰ对金黄色葡萄球菌具有良好的抑制活性,最小抑菌浓度为4 mg/L,抑菌效果优于市售的新洁尔灭,与氨苄青霉素钠相当。     

木质素聚醚非离子表面活性剂的合成与性能研究

以造纸废液中回收的碱木质素为原料通过与环氧丙烷和环氧乙烷的烷氧化反应,合成了木质素聚醚非离子表面活性剂.得到的产物在不同pH值条件下均具有较好的溶解性,使用红外光谱分析对产物的结构进行了表征,使用紫外光谱定量分析方法测定了产物中木质素的含量,并对其表面活性、亲水亲油平衡(HLB)值、浊点、增容性等性能进行了测试.当 n (木质素羟基)∶ n (环氧丙烷)为1∶10,产物对苯的增容性能为0.75mL/g,泡沫高度110mm,HLB值为14.7,浊点为42.7℃,木质素聚醚质量分数2.5%时,表面张力可达到37.0mN/m,测试数据证明合成的木质素非离子表面活性剂具有良好的表面活性.     

环氧亚麻油-棕榈蜡复合乳液的制备及处理材的疏水性

为改善木材表面的疏水性能,以环氧亚麻油与棕榈蜡制备的复合乳液用于青杨(Populus cathayana Rehd.)试样常压浸渍处理,考察环氧亚麻油与棕榈蜡的配比及亲水亲油平衡值(HLB值)对复合乳液稳定性和粒径的影响,并评价复合乳液处理材的疏水性。结果表明,当环氧亚麻油/棕榈蜡配比为3:7、复合乳液的HLB值为17.0时,复合乳液的平均粒径为223.5 nm,离心稳定性达1级;处理材横切面与弦切面30 s内的接触角达到119.2°和105.8°,流失率为6.1%,对提高木材表面疏水性能具有实际应用意义。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

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.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

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.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

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.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

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.     

CAD与建筑设计的关系

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。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

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.     

Risk Perception Among Non-industrial Private Forest Owners

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.     

Interactions in decomposition and N mineralization between tropical legume residue components

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.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

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.