紫胶改性酚醛模塑料的研究

紫胶是一种重要的林特产品，我国的年产量仅次于印度、泰国居世界第三位。本研究首次采用紫胶的改性产品（RL2树脂）改性酚醛模塑料通用类产品（PF2A2131、PF2A1141）获得成功。产品质量达到或过了GH1404－86规定的各项技术指标，成本比不同紫胶树 的同类产品的约降低10％，填实国内紫胶树脂用于生产紫胶改性酚醛模塑料的空白。     

改善植物蛋白乳化特性的方法研究

综述了三种提高植物蛋白乳化特性的方法：化学改性法,物理改性法和酶改性法。并展望了提高植物蛋白乳化性的未来发展趋势。     

植物蛋白改性剂对脲醛树脂胶粘剂性能影响研究

以脲醛树脂为改性研究对象,选择玉米蛋白、棉籽蛋白和大豆蛋白三种植物蛋白做为改性剂,从粘度、pH值、固化时间、胶合强度和甲醛释放量等方面入手,对不同添加量的改性效果进行研究的结果表明,三种蛋白对甲醛释放量影响相对差别较小,添加量为20％的棉籽蛋白为改性脲醛树脂的最优选择,玉米蛋白次之.     

改性脲醛树脂的合成及其对木材改性效果试验

以聚顺丁烯二酸二乙醇酯（ＰＭ）和三聚氰胺（Ｔ）分别改性脲醛树脂（Ｕ－Ｆ），合成了两种稳定改性脲醛树脂－ＰＭ－Ｕ－Ｆ和Ｔ－Ｕ－Ｆ，考察了改性树脂中ＰＭ的含量和Ｔ／Ｕ摩尔比对木材改性效果的影响，试验结果表明，这两种改性脲醛树脂对板栗木、青岗木均有良好的改性效果。     

利用化学改性剂提高木材尺寸稳定,耐腐和阻燃性能

用木材化学改性剂（ＬＭ）改性木材（杨木、马尾松等），当木材化学改性剂增重（ＷＰＧ）达２０％─３０％时，可获得很高的抗缩系数（ＡＳＥ值）或尺寸稳定性。改性后木材具有良好的防腐、防白蚁、防霉、防蓝变的性能，并且还可获得很高的阻燃性能。用木材化学改性剂（ＬＭ）改性后的木材无毒（ＬＤ５０＞１００００ｍｇ／ｋｇ），无味，对人，畜无害。     

树皮的化学改性及其吸附特性研究

通过甲醛和环氧氯丙烷交联马尾松树皮，得到两种改性树皮；甲醛改性树皮（简称FMB）和环氧氯丙烷改性树皮（简称EMB）。讨论了不同改性条件对树皮得率的影响，研究了FMB、EMB对阳离子型染料碱性桃红和重金属离子铜离子的吸附特性，实验结果表明：（1）通过上述改性，可改善树皮的化学稳定性，避免有色物质的流出；（2）与未改性树皮相比，FMB、EMB对碱性桃红的吸附容量提高了约50%，达95mg/g；对铜离子的吸附容量提高了约56%，达78mg/g；（3）两种改性方法相比，吸附容量相近，但甲醛法改性成本低廉，污染少，综上所述，FMB、EMB是一种具有潜在应用价值的水处理材料。     

桐油改性酚醛树脂的研究（Ⅰ）──合成、机理与结构表征

通过桐油和苯酚在催化剂存在下的反应，然后再在碱性催化剂存在下与甲醛反应制得一种桐油改性甲阶酚醛树脂，探讨了反应的机理。利用化学分析、元素分析和凝胶渗透色谱分析对第一步反应进行了研究，发现１摩尔桐油大体上可与６摩尔苯酚发生反应，反应过程中同时存在桐油自聚和降解现象，随着初始苯酚／桐油摩尔比的降低，该现象更为明显。利用紫外光谱、红外光谱和￣１ＨＮＭＲ等分析手段对桐油－苯酚反应产物和桐油改性酚醛树脂的结构进行了表征，证明桐油与苯酚反应属于共轭三烯对酚核的烷基化反应，或酚核对共轭三烯的亲核取代反应，酚核取代位置为酚羟基的对位或邻位，酚羟基未参加反应，在改性酚醛树脂骨架上引入了桐油分子链。     

热改性木材化学成分变化及其影响因素

木材易产生吸湿变形和腐朽等问题，影响其应用效果。热改性处理可有效提升木材的尺寸稳定性和耐久性，并具有无毒、环保的特点，是一种极具潜力的木材改性方法。文中综述了木材组分（纤维素、半纤维素、木质素、抽提物）在热改性过程中发生的化学变化，以及木材树种和部位、处理介质、处理温度和时间对木材热降解的影响。经不同热改性工艺处理后，木材的化学成分变化存在较大差异。探明热改性工艺、热改性材化学成分变化和性能之间的响应机制，将有助于开发或优化热改性技术，从而得到性能优异的热改性材，拓宽其应用领域。     

桐油改性酚醛树脂的研究（I）：合成,机理与结构表征

通过桐油和苯酚在催化剂存在下的反应，然后再在碱性催化剂存在下与甲醛反应制得一种桐油改性甲阶酚醛树脂，探讨了反应的机理。利用化学分析、无素分析和凝胶渗透色谱分析对第一步反应进行了研究，发现１摩尔桐油大体上可与６摩尔苯酚发生反应，反应过程中同时存在桐油自聚和降解现象，随着初始苯酚／桐油摩尔比的降低，该现象更为明显。利用紫外光谱、红外光谱和＾１ＨＮＭＲ等分析手段对桐油－苯酚反应产物和桐油改性酚醛树脂的结     

木地板的化学改质

木地板是一种特殊的制品，它必须有一定的表面硬度、尺寸稳定性和阻燃性，这些必备的性能非通用的改性方法所能提供，必须在新的领域中探索新的方法，改性硅溶胶就是一种较理想的改质剂。     

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.