桉叶油与其它药物的联合抗菌作用

本文测定了桉叶油对5种细菌的最小杀菌浓度,并对桉叶油与丹参、青霉素、链霉素、卡那霉素对金黄色葡萄球菌和大肠埃希氏菌等的联合抗菌作用做了初步实验研究.通过对小数杀菌浓度指数的测定和平板纸条法联合抗菌作用,证实桉叶油除有广泛的抗菌作用外,而且是一种有效的抗菌增强剂,与丹参和抗生素都有协同作用,可增强丹参和抗生素的抗菌功效.     

用苯乙酮作内标测定桉叶油中1，8-桉叶油素的研究

通过用环己酮和苯乙酮作内标物，对含量80％桉叶油中1，8-桉叶油素含量的测定进行比较．结果表明，用苯乙酮作内标测定，标准偏差为0．97．变异系数为0．33％。而且毒性较小．是较理想的内标物。     

用苯乙酮作内标测定桉叶油中1,8-桉叶油素的研究

通过用环己酮和苯乙酮作内标物,对含量80 %桉叶油中1,8-桉叶油素含量的测定进行比较,结果表明,用苯乙酮作内标测定,标准偏差为0.27,变异系数为0.33 %,而且毒性较小,是较理想的内标物.     

中国桉叶油的开发与利用

桉树是自然分布在澳大利亚等国家的重要经济树种，也是生长最快的材用树种之一，至今已有120多个国家和地区引种栽培。全世界现有桉树人工林面积600余万hm2，年产木材6000多万m3。中国引种桉树已有106年的历史，至今中国已有20个省、自治区、直辖市的600多个县种植了桉树人工林80万公顷，四旁种植18亿株，种植面积仅名次于巴西，年产桉树木材约200多万m3，桉叶油3000吨。桉叶油是桉树（Eucalyptus）叶油腺细胞分泌出来的芳香精油。中国桉叶油工业体系的建立是最近二十多年的事。由于生长快，栽种后短期内即可生产桉叶油，取得了良好的经济…     

互叶白千层精油化学成分的研究

采用毛细管气相色谱和色谱－质谱计算机联用系统,分析了互叶白千层精油的化学成分。其主要万分是松油醇－４,α－松油烯,γ－松油烯,１,８－桉叶油素。     

不同微量元素和土壤酸碱性对油樟叶1,8-桉叶油素含量的影响

微量元素在植物生长中具有重要作用,开展油樟(Cinnamomum longepaniculatum)施微量元素的研究,对油樟的定向培育具有重要意义。试验结果表明,各微量元素和土壤酸碱性对油樟叶中1,8-桉叶油素含量影响的主次顺序不同;硫酸锰、硫酸锌对油樟叶中1,8-桉叶油素含量的影响显著,硫酸亚铁、亚硒酸钠和p H值对油樟叶中1,8-桉叶油素含量的影响均不显著。综合考虑各处理对油樟叶中1,8-桉叶油素的影响情况,最佳的处理是A₁B₄C₂D₃E₃,即喷施0.5%硫酸锰,0.1%硫酸锌,0.3%亚硒酸钠,p H值为5.5,不施硫酸亚铁时的油樟叶中1,8-桉叶油素含量最高。     

蛹虫草固体培养菌质粗多糖提取与分离工艺研究

为探明蛹虫草固体发酵新型培养基茵质中多糖的含量及结构,并探明回流提取方法对此类培养基中多糖提取的条件。采用正交实验确定最佳提取条件,采用苯酚一硫酸法测定茵质中的多糖含量,并用阴离子交换柱进一步分离粗多糖。结果：回流提取的最佳条件为80℃下,料液比1：20回流提取2h,提取次数为3次。在此条件下多糖含量为6．93％。其DPPH清除率可达50％以上,粗多糖经阴离子柱分离得到3种不同的糖蛋白。结论：该实验方法操作简易,条件易控制,结果精准,适合此种培养基中蛹虫草多糖的测定及分离纯化。     

蓝桉叶油脚油气相色谱分析研究

对取自昆明两个香料厂的蓝桉叶油脚油进行系统的ＧＣ及ＧＣ－ＭＳ分析，在已检出的７０余个成分中鉴定了４８个化合物，证明其主要成分为α－松油醇（样品Ａ：２７．９％，样品Ｂ：５．５％）和（＋）－香木兰烯（Ａ：１７．８％；Ｂ：２６．８％）。其它成分有愈创木烯，别香木兰烯，表蓝桉醇，喇叭茶醇，古芸烯，双表喇叭茶醇（Ｄｉｅｐｉｐａｌｕｓｔｒｏｌ）等。它们可作为萸的前驱体化合物使用，即可经脱水，脱氢转化为萸类化合     

桉叶精油化学组分研究

采用气相色谱与气-质联用法对广东产柠檬桉、窿缘桉和雷林1号桉叶精油进行定量和定性研究。确定出柠檬桉叶油29种化合物,窿缘桉和雷林1号桉叶油30多种化合物。色谱定量分别采用面积归一化法和13烷烃内标法,测得柠檬桉叶油含香草醛72.80％、香草醇14.51％;窿缘桉和雷林1号桉叶油含桉叶油素分别为35.69％和37.49％。从精油分析结果得知:窿缘桉酷似雷林1号桉,亲缘关系密切,而柠檬桉与它们虽同系桉树属,但性质差别甚大。     

云南栽培的材油兼用型桉树的桉叶油产油性能研究

以直干桉为代表,对云南栽培的材油兼用型桉树进行了(1)林木不同修叶量与其生长量关系的研究;(2)不同栽培型的林木桉叶产量及不同坡向种植的林木桉叶出油率;(3)不同采叶季节的桉叶出油率;(4)鲜叶及自然风干叶的桉叶出油率等的桉叶油产油性能研究.其系列研究结果表明:桉树林木的修叶量以修叶高度占植株树冠长度1/3为标准进行,此修叶标准不影响桉树的生长;桉叶产量与种植地的立地条件和栽培型密切相关,只有在种植地立地条件较好,经营水平较高的条件下,才能使所栽培的桉树林木获得较高的桉叶产量;生长在阳坡的桉树其桉叶的出油率较阴坡高,但差异不显著;在桉树生长缓慢的季节,其林木桉叶的出油率较生长迅速季节高,但差异不显著;自然风干叶较鲜叶出油率高,但差异不显著.此外,对云南栽培的几种材油兼用型桉树的桉叶油产油性能比较的研究结果则表明:直干桉、蓝桉、史密斯桉单位面积的产叶量、桉叶产油量有一定差异,但差异不显著.桉叶油中所含的桉叶素以史密斯桉最高,为81.6 %,其次是直干桉,为71.1 %,蓝桉为69.2 %.     

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.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

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。     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Growth of Mixed Birch-Coniferous Stands in Relation to Pure Coniferous Stands at Similar Sites in South-eastern Norway

Mean age, mean and top heights and yield were studied in 20 mixed stands of birch ( Betula pubescens Ehrh. and B. pendula Roth) and Picea abies (L.) Karst. and nine mixed stands of birch and Pinus sylvestris L. in south-eastern Norway. Each mixed stand and the adjacent pure coniferous stand (control) were growing under the same site conditions and had not been commercially thinned. There were no significant differences in mean age at breast height or in top heights between birch and conifers in the mixed stands, while mean height was significantly higher for birch than for spruce. A growth index was calculated based on total volume and age at breast height. For the spruce sites the growth in young mixed stands (birch < 17 m) was superior to that of pure spruce, while the difference was insignificant in older stands. The growth index correlated positively with the ratio between generatively and vegetatively regenerated birch trees, and negatively with the age of the oldest species in the mixture and with site quality. For the pine sites there was no significant difference in the growth index between mixed birch-pine and pure pine stands. A mixture effect of birch on the volume yield of spruce or pine could not be demonstrated.     

Defoliation by the Needle-shortening Pine Gall Midge,Thecodiplosis brachyntera,on Pines in Central Sweden

An outbreak of the needle-shortening pine gall midge, Thecodiplosis brachyntera , occurred on Scots pine, Pinus sylvestris (L.) and lodgepole pine, P. contorta (Dougl.) in central Sweden during 1995-1998. The larval feeding of T. brachyntera kills current-year needles and heavy infestation causes severe defoliation. A pattern of fluctuating defoliation among years and sites was found on both pine species. Defoliation was evenly distributed in the crown of P. sylvestris during years of high as well as low infestation; apical whorls had as much defoliation as basal whorls. In P. contorta , however, there was a tendency for defoliation to be concentrated on branches in the most apical whorls. Growth ring increments on P. sylvestris with high levels of defoliation (71%) did not differ from trees with moderate levels (26%) of defoliation. Shoot lengths were significantly shorter, however, on heavily infested trees the year after defoliation.