不脱水低毒脲醛树脂的研制

应用胶体理论，制得不脱水低毒脲醛树脂胶，并探索了其合成机理，所得胶达到ＧＢＴ１４７３２－９３要求，用此胶压制的刨花板满足ＧＢＴ４８９７－９２Ａ类板一等品要求，甲醛释放量达到欧洲Ｅ２级。     

覆塑竹碎料板生产工艺研究

研究了覆塑竹碎料板生产工艺。研究表明：密度为１．０ｇ／ｃｍ３的覆塑竹碎料板完全符合国标竹编胶合板标准（ＧＢ／Ｔ１３１２３－１３１２４－９１）及建筑工业行业竹编胶合板模板标准（ＪＧ／Ｔ３０２６－１９９５）要求,能够作为混凝土模板使用。     

芦苇－杨木刨花板制造工艺研究

分析了以芦苇为单一原料制造符合标准要求的刨花板的困难所在。探讨了以芦苇一杨木混合物为原料，压制脲醛胶刨花板。结果表明，当芦苇和杨木的混合比为６０％：４０％时，刨花板的物理力学性能达到刨花板国家标准（ＧＢ／Ｔ４８９７－９２）规定的指标要求。     

玉米秆—亚麻屑刨花板制造工艺研究

本文分析了以单一玉米秆为原料制造符合标准的刨花板的困难所在。探讨了以玉米秆－亚麻屑混合原料压制脲醛胶刨花板的可行性。结果表明，玉米秆和亚麻屑的混合比例为５０：５０，刨花板的物理力学性能达到现行刨花板国家标准（ＧＢ／Ｔ４８９７－９２）规定的指标要求。     

橡胶木胶合板阻燃技术研究：Ⅰ.橡胶木胶合板的阻燃处理

橡胶木胶合板的阻燃处理试验结果表明，在ＷＦＲ１基础上调整后的配方ＷＦＲ１－２－ａ处理的橡胶木胶合板具有好的阻燃效果，产品按ＧＢ／Ｔ ８６２５－８８检测，达到建筑材料难燃Ｂ１级，胶合强度达到未阻燃处理胶合板的水平。     

玉米秆－亚麻屑刨花板制造工艺研究

本文分析了以单一玉米秆为原料制造符合标准的刨花板的困难所在。探讨了以玉米秆—亚麻屑混合原料压制脲醛胶刨花板的可行性。结果表明，玉米秆和亚麻屑的混合比例为５０：５０，刨花板的物理力学性能达到现行刨花板国家标准（ＧＢ／Ｔ　４８９７－９２）规定的指标要求。     

橡胶木胶合板阻燃技术研究 Ⅰ.橡胶木胶合板的阻燃处理

橡胶木胶合板的阻燃处理试验结果说明，在ＷＦＲ１基础上调整后的配方ＷＦＲ１－２－ａ处理的橡胶木胶合板具有好的阻燃效果，产品按ＧＢ／Ｔ８６２５－８８检测，达到建筑材料难燃Ｂ１级，胶合强度达到未阻燃处理胶合板的水平。     

稻草原料酸碱性及稻草中密度纤维板的性能

测试分析了稻草原料的ｐＨ值和缓冲容量，分别使用脲醛树脂胶和异氰酸酯胶在特定工艺条件下压制了稻草中密度纤维板，并测试了板材性能。结果表明：１）稻草秸秆原料呈弱碱性，缓冲容量远高于普通木材；经热磨处理获得的稻草纤维呈弱酸性，其缓冲容量虽较稻草秸秆有一定幅度的下降，但仍高于普通木材；２）脲醛树脂或异氰酸酯稻草中密度纤维板的性能都明显优于相应的碎料板；在密度０．８０ｇ／ｃｍ３和施胶量１７％的条件下，脲醛树脂稻草中密度纤维板性能达到国标ＧＢ／Ｔ１７６５７－１９９９一等品的要求，在密度０．８０ｇ／ｃｍ３和施胶量６％的条件下，异氰酸酯稻草中密度纤维板性能达到国标ＧＭ／Ｔ１７６５７－１９９９优等品要求。     

三聚氰胺改性脲醛树脂的制备及其在室外型中纤板上的应用

介绍了三聚氰胺改性脲醛树脂的主要制备工艺，并对该树脂在室外型中密度纤维板中的使用条件如热压参数、施胶量、板坯含水率等进行了研究。试验结果表明用三聚氰胺改性脲醛树脂压制的中纤板的物理力学性能达到ＧＢ／Ｔ１１７１８－１９９９室外型中纤板的各项指标     

芦苇刨花板贴面技术的研究

随着芦苇刨花板的问世，它的使用和深加工技术也日益得到重视和研究。为了扩大芦苇刨花板的应用范围，为生产企业提供合理的工艺参数，本研究在试验室进行了制板试验，并在生产企业通过了生产性试验，其产品性能符合ＧＢ／Ｔ１５１０２－９４标准要求。１试验材料与设备１...     

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.