纯天然长效防蛀剂

本文提供一种纯天然长效防蛀剂的制备方法，其主要是以天然物质作原料，现介绍如下： １．樟树废料：来自樟树枝、叶、根、皮、果实及木材加工中的边角碎料、锯屑，含樟脑原油达２％～８％，具有良好的防蛀作用。 ２．大叶桉（桃金娘科）枝、叶，主要从修整做形时获得，含挥发油（桉树油），主要成分为按树醇（又称按树脑），具有较好的防蛀驱虫和杀菌作用，木材中含桉树油甚少。 ３．月桂（樟科）枝、叶含挥发性月桂油，主要成分为桉树醇。 ４．香茅草（禾本科），全株含精油，主要成分是香茅醛，龙牛儿醇和香茅醇，有浓郁野山椒气味，有杀…     

柠檬醛选择性加氢的催化研究进展

总结了近5年来柠檬醛催化加氢的研究进展。重点介绍了催化剂的活性组分、载体和制备方法等对柠檬醛选择性加氢催化性能的影响,探讨了催化选择性合成香叶醇与橙花醇、香茅醛、二氢香茅醛、香茅醇和3,7-二甲基辛醇等单萜化合物,以期为进一步研究柠檬醛加氢提供参考。     

非水相体系中木瓜脂肪酶催化合成萜烯醇芳香酯的研究

为建立经济、绿色、高效的萜烯醇芳香酯合成工艺,以木瓜蛋白酶粗品为原料制备获得了天然固定化木瓜脂肪酶(CPL),研究了CPL在非水相体系中催化合成萜烯醇芳香酯的效果,探讨了在有机溶剂体系中萜烯醇种类、有机溶剂种类以及初始水分活度对反应的影响。结果表明:伯醇类萜烯醇(香茅醇和香叶醇)是较适宜的底物,中等极性的有机溶剂如正己烷为适宜的反应溶剂,0.328的初始水分活度有利于CPL发挥催化活性,此时转化率为95.2%,与商业脂肪酶催化效果相当。CPL在有机溶剂中重复使用性较差,考察了不同离子液体处理方法对CPL催化性能的影响,结果表明,使用微量离子液体对CPL进行包裹前处理可以显著地提高CPL的重复使用性,反应15次后,催化活性仍保留90%以上。     

紫苏醇的合成研究进展

综述了紫苏醇合成的研究进展,分析了各合成路线的关键步骤,讨论了各种方法的特点,着重介绍了2,10-环氧蒎烷液相重排合成紫苏醇的各种Bronsted酸催化剂。简述了紫苏醇的天然存在、单离方法及其应用研究成果。     

油橄榄羟基酪醇的生物合成及其衍生物研究进展

介绍了传统化学合成羟基酪醇的方法,针对化学合成反应步骤多、催化剂昂贵、产率低、污染大等问题,重点总结了以橄榄苦苷和酪醇为原料生物法合成羟基酪醇的途径,同时还综述了羟基酪醇烷基醚、脂肪酸酯、糖基化等衍生物的制备方法、生物活性及其构效关系,为羟基酪醇及其衍生物批量制备及其抗肿瘤、抗癌、心脑血管疾病新药的筛选提供参考和指导作用。     

内型异莰烷基甲醇的合成

用莰烯经Ｖｉｌｓｍｅｉｅｒ－Ｈａａｃｋ甲酰化反应制得的莰烯醛为原料，分别在钯和镍催化下进行高压氢化合成了内型异莰烷基甲醇，并对先钯催化氢化成内型异莰烷基甲醛再经镍催化氢化转变成醇的分步法及镍催化下高压氢化成异莰烷基甲醇的一步法进行了比较，结果认为要使内型醇的得率高，还是用分步法更为适宜。以上两种合成法均优于文献报道的方法。本文还对ω－羟甲基莰烯的氢化进行了探讨，并认为不能从它合成异莰烷基甲醇。     

香茅醛气相加氢制香茅醇反应的研究

采用连续流动微型固定床反应装置，研究了Ｍ催化剂对香茅醛在常压下气相加氢香茅醇的反应。通过对几种不贩金属催化剂的筛选，得到了一种转化率和选择性均较高的加氢催化剂Ｍ催化剂。考察了该催化剂在不同焙烧温度和不同的负载量下对其活性的影响，同时对反应的影响也进行了探讨。     

松材线虫(Bursaphelenchus xylophilus)耐久型幼虫(L_Ⅳ)携带的香茅醇假单胞杆菌(Pseudomonas citronellolis)分离与鉴定

[目的]目前有关松材线虫与伴生细菌的关系及伴生细菌的病原作用是松树枯萎病研究的重点。为了揭示松材线虫与伴生细菌之间存在的密切关系,作者对松材线虫L_Ⅳ幼虫携带的细菌进行了分离鉴定。[方法]根据培养性状和16S rDNA序列同源性以及系统发育学等方面进行分析鉴定。[结果]确定L_Ⅳ幼虫携带的是香茅醇假单胞杆菌(Pseudomonas citronellolis),携带率为100%;每条L_Ⅳ幼虫携带量在1.4×10~5~4.5×10~5。L_Ⅳ幼虫生活在松褐天牛体内,是引起松材线虫病侵染流行的唯一虫态;新发现的香茅醇假单胞杆菌能分解纤维素及降解或合成萜烯和酚类化合物。[结论]L_Ⅳ幼虫携带香茅醇假单胞杆菌的发现,揭示了松树、松褐天牛、松材线虫、细菌同为一体的紧密关系,并为揭示松树枯萎病机制提供了一种新病原和重要的研究思路。     

利用松节油合成檀香型香料

目前市场上檀香型香料紧俏,天然檀香资源稀缺,合成檀香供不应求,我国盛产松节油,价廉质优。本文就天然檀香油及以松节油为原料合成的檀香型香料品种作一综合介绍。     

土面增温剂配方

中国科学院地理研究所原料: ①脂肪酸残渣,以酸价在40-70之间的为好.目前使用的脂肪酸残渣有两个来源:一是石腊氧化合成脂肪酸的釜底残渣;一是天然动植物油(骨油、豆油、棉籽油等)的油脚经提取脂肪酸后的釜底残渣. ②高碳醇,蒸馏混合醇的釜底醇渣,其中C16以上的醇要占80%以上.     

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。     

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.     

Key Habitats in the Norwegian Production Forest: A Case Study

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.