氯化亚铜催化的月桂烯氢氯化反应的研究（Ⅰ）──产物分布和反应机理

研究氯化亚铜催化的月桂烯氢氯化反应的产物分布和反应机理，考察了催化剂和稀释剂对产物分布的影响。结果表明：（１）月桂烯的氢氯化反应生成月桂烯基氯、芳樟基氯、橙花基氯、香叶基氯和。α－松油基氯５种单氯化物，产物中３种烯丙基型氯化物的含量约达到９０％；（２）月桂烯的氢氯化反应是通过共轭双键吸附在催化剂表面上，并与吸附的氯化氢形成表面活化络合物进行的，该表面活化络合物经两个共振结构的碳正离子中间体分别生成芳樟基氯、橙花基氯和香叶基氯。并对提出的反应机理进行了讨论。     

四川宜宾地区樟科十四种精油化学成分的研究

为开发四川省宜宾地区樟科植物精油资源,采用GC—MS与气相色谱保留指数定性,微机在线实时采样测定各成分相对含量。结果表明樟属的几种植物其根部精油都主含黄樟油素。樟属同种植物枝叶精油却有不同生化类型;鉴定确认樟树种中有芳樟叶油主含芳樟醇(66％),樟叶油主含1,8-桉叶油素(61％),臭樟叶油主含β—橙花叔醇(26％);黄樟种中有大叶芳樟叶油主含d-芳樟醇(90％),大叶脑樟叶油主含d-樟脑(65％)。而樟属肉桂叶油主含反—肉桂醛(90％),银木叶油主含樟脑(37％)、顺—甲基异丁香酚(21％)。木姜子属山苍子油主含橙花醛(28％)和香叶醛(42％)等等。这些资源精油化学成分,特别是具有强抗菌活性成分的鉴定,为香料工业提供优质单离香料之原料有着现实应用价值。     

合成香叶基丙酮的研究

近年来，我国湿地松采脂生产不断增长，其松节油中β－蒎烯含量约为２５－３５％。为了更好地利用它，重点研究了从它的热异构产物月桂正确性 基丙酮的新路线。香叶基丙酮是ＶＥ生产的重要支链化合物－Ｃ２０的异植物醇的中间体。研究工作考察了月桂烯和氯化氢１、，４－加成反应过程中，月桂烯纯度、氯化氢加成量对该反应主产物香叶基氯和橙花基氯产率的影响，同时研究了它们和丙酮取代反应的条件及影响因素，如温度、催化剂、时间     

氯化亚铜催化的月桂烯氢氯化反应的研究（I）：产物分布和反应机理

研究氯化亚铜催化的月桂烯氢氯化反应的产物分布和反应机理，考察了催化剂和稀释剂对产物分布的影响。结果表明：（１）月桂烯的氢氯化反应生成月桂烯基氯、芳樟基氯、橙花基氯、香叶基氯和α－松油基氯５种单氯化物，产物中３种烯丙基型氯化物的含量约达到９０％；（２）月桂烯的氢氯化反应是通过共轭双键吸附在催化剂表面上，并与吸附的氯化氢形成表面活化络合物进行的，该表面活化络合物经两个共振结构的碳正离子中间体分别生成芳     

几种油茶挥发物对刺股沟臀肖叶甲的引诱试验

刺股沟臀肖叶甲是对油茶高度危害的食叶害虫之一,主要取食油茶的嫩枝嫩叶,导致油茶生长不良,结果减少。本研究以开发刺股沟臀肖叶甲的引诱剂为目的,选择油茶嫩枝挥发物的主要成分,进行引诱试验。林间引诱结果表明,来自油茶嫩枝的醛类化合物壬醛的引诱作用最大;萜烯类的芳樟醇和香叶醇也对刺股沟臀肖叶甲具有明显的引诱效果,α-萜品醇和橙花叔醇则不具有引诱作用;而来自油茶花的挥发物水杨酸甲酯、(Z)-3-己烯-1-醇、(Z)-3-己烯丁酯没有表现出引诱作用。α-萜品醇、芳樟醇、香叶醇、橙花叔醇1︰1︰1︰1的混合物对刺股沟臀肖叶甲同样具有引诱效果,但其诱捕量显著小于香叶醇的诱捕量,说明α-萜品醇、橙花叔醇对香叶醇、芳樟醇的引诱作用具有抑制效果。进一步的试验表明,芳樟醇、香叶醇、水杨酸甲酯、(Z)-3-己烯-1-醇、壬醛5种物质的比例为1︰1︰1︰1︰1和1︰2︰1︰1︰4的混合物作为引诱剂,可诱捕到更多数量的刺股沟臀肖叶甲。     

香叶基丙酮

香叶基丙酮又名二氢假紫罗兰酮,是一种具有木兰香气的名贵香料。香叶基丙酮巳广泛应用于日化、食品、医药等行业,一般用于配制日化香精,作为食品添加剂和医药中间体。异植物醇是合成维生素Ｅ的一个重要侧链,而维生素Ｅ需求的增加必然要扩大异植物醇的生产。作为异植物...     

橙花叔醇

橙花叔醇是一种贵重的香料，具有相似于玫瑰和苹果的微弱花香，可作为食品添加剂和医药中间体。９０年代，随着异植物醇需求量的大增，作为异植物醇的中间体，需求量逐年提高，据预测我国仅用于异植物醇生产的橙花叔醇用量２０００年前达到３０００吨以上，而国内生产能力...     

松节油合成生物活性角鲨烯反应路线的研究

基于对深海鲨鱼肝油中的珍贵天然生物活性化合物角鲨烯以及我国丰富的天然单萜烯资源松节油化学结构的对比研究．在考察献资料和现有研究成果的基础上．作创新性地提出了从松节油合成角鲨烯的构想．其可行的合成路线主要包括松节油(蒎烯)→蒎烷→氢过氧化蒎烷→蒎醇→芳樟醇→香叶基丙酮→橙花叔醇→金合欢醇→金合欢基溴→角鲨烯等9步化学反应。在已有研究基础上．通过对合成金合欢基溴及金合欢基溴偶联的反应进行重点的详细研究后．贯通了合成路线．实现了从可再生天然精油松节油合成珍稀资源角鲨烯的独创设想．获得了目的产物角鲨烯。本概述了合成路线中每一步合成反应的现状和要点。     

髯毛樟叶和樟叶精油化学成分的研究

用毛细管气相色谱法和色谱—质谱—计算机联用技术对四川省的髯毛樟叶和樟叶的精油化学成分进行了研究.从髯毛樟叶精油中鉴定出45个成分,其主要成分是1.8—桉叶油素36.28%、香叶醛12.16%、橙花醛0.06%、香桧烯10.79%等,从樟叶精油中鉴定出49个成分,其主要成分是樟脑37.36%、β—橙花叔醇22.28%等.前者为第一次研究,后者可能是樟树的一个新的生化类型.这一研究为植物分类和资源利用提供了依据.     

多酚酸酯稳定剂对生物柴油室温稳定性的影响

室温条件下,测定了含不同多酚酸酯稳定剂的生物柴油过氧化值6个月内随时间的变化曲线.用于研究的23种稳定剂,包括:5种没食子酸烷基酯、6种没食子酸萜醇酯(没食子酸金合欢酯、没食子酸香叶酯、没食子酸芳樟酯、没食子酸橙花叔醇酯、没食子酸薄荷酯和没食子酸氢化松香酯)、3种合成抗氧化剂、2种天然抗氧化剂、3种双组分稳定剂、2种三组分稳定剂以及2种含协同增效剂的稳定剂.结果显示没食子酸甲酯对生物柴油的室温稳定化作用明显强于其它4种没食子酸烷基酯、6种没食子酸萜醇酯、3种合成抗氧化剂和2种天然抗氧化剂;没食子酸金合欢酯对生物柴油的室温稳定化作用强于其它5种没食子酸萜醇酯;双组分稳定剂和三组分稳定剂等复合组分稳定剂没有明显改善生物柴油的室温稳定性;含协同增效剂的稳定剂能提高生物柴油的室温稳定性,协同增效剂柠檬酸的作用特别明显;杂质铁和杂质铜会降低生物柴油的室温稳定性,且杂质铁的影响大于杂质铜.     

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.