酸功能化离子液体磺烷基咪唑对甲苯磺酸盐催化合成松香甲酯的研究

制备、表征了酸功能化离子液体1-(3-磺酸)丙基-3-甲基咪唑对甲苯磺酸盐((HSO3-pmim)pTSA),并用于催化合成松香甲酯的反应研究,详细考察了甲醇用量、催化剂用量、反应温度、反应时间等因素对反应结果的影响,得到较佳的工艺条件:甲醇15 g,离子液体2.5 g,松香5 g,反应温度200 ℃,反应时间4 h.在该条件下,所得产物松香甲酯的酸值为17.4 mg/g;并对离子液体(HSO3-pmim)pTSA的重复使用性能进行了考察,分出的离子液体在不经处理直接重复使用5次时,所得产物松香甲酯的酸值为20.1 mg/g,具有较好的可重复使用性.     

酸功能化离子液体磺烷基咪唑磷酸盐催化合成乙酸松油酯的研究

制备、表征了酸功能化离子液体1-（3-磺酸）丙基-3-甲基咪唑磷酸二氢盐（（HSO，-pmim）H2PO4），并用于催化合成乙酸松油酯的反应研究，考察了反应时间、反应温度、原料配比、催化荆用量等因素对反应的影响。在松油醇5．1g、n（松油醇）：n（乙酸酐）1：1．5、离子液体1．5g、反应温度40℃、反应时间8h的工艺条件下，松油醇转化率为100％，乙酸松油酯的选择性为87．2％；并对离子液体（HSO3-pmim）H2PO4的重复使用性能进行了考察，离子液体在不经处理直接重复使用6次后，松油醇的转化率为99．4％，乙酸松油酯的选择性为88．6％，具有较好的重复使用性能。     

硫酸-离子液体复合催化剂催化松香聚合反应工艺的研究

首次将3种硫酸-离子液体复合催化剂[H2SO4-（C2mim）BF4、H2SO4-（C4mim）BF4和H2SO4-（C8mim）BF4]用于催化松香聚合反应中，H2SO4-（C4mim）BF4和H2SO4-（C8mim）BF4均显示出很好的催化活性。以H2SO4-（C8mim）BF4为代表，详细考察了不同溶剂、H2SO4用量、反应温度和反应时间等因素对反应结果的影响，得到较佳的工艺条件：松香和甲苯质量比1：1，催化剂用量为松香质量的30％．反应温度70℃，反应时间4h。在该条件下，得到的聚合产物软化点为135℃，酸值为142mg/g并对H2SO4-（C8mim）BF4复合催化剂的重复使用性能进行了考察，该复合催化剂克服了传统催化剂的一些缺点，既简化了产物的分离。又可以重复使用。     

酸功能化离子液体磺烷基咪唑磷酸盐催化合成乙酸松油酯的研究

制备、表征了酸功能化离子液体1-(3-磺酸)丙基-3-甲基咪唑磷酸二氢盐((HSO3-pmim)H2PO4),并用于催化合成乙酸松油酯的反应研究,考察了反应时间、反应温度、原料配比、催化剂用量等因素对反应的影响.在松油醇5.1 g、n(松油醇):n(乙酸酐)1:1.5、离子液体1.5 g、反应温度40 ℃、反应时间8 h的工艺条件下,松油醇转化率为100 %,乙酸松油酯的选择性为87.2%;并对离子液体(HSO3-pmim)H2PO4的重复使用性能进行了考察,离子液体在不经处理直接重复使用6次后,松油醇的转化率为99.4%,乙酸松油酯的选择性为88.6%,具有较好的重复使用性能.     

松香的硝酸开环氧化

研究了硝酸氧化松香的反应,以探讨硝酸用量和反应时间对氧化反应的影响。采用红外光谱、紫外光谱、液质联用对松香氧化产物的结构进行了测定。实验结果表明：以硝酸为氧化剂,乙酸乙酯为溶剂,在反应温度为75℃,反应时间为8h,n硝酸：n松香=22：1时,氧化产物酸值达到318mgKOH／g。松香中的主要成分已发生了氧化,共轭双键断裂生成了多羧基氧化产物,初步推断出可能的3个主要氧化产物的结构分别为：3．异丙基-6．（1,3-二甲基-2,3-二羧基环己基）苯甲酸,6-（1,3-二甲基-2,3-二羧基环己基）．1,3-苯二甲酸,12．硝基-7,11,14-三羰基-△8（9）-枞酸。     

硫酸-离子液体复合催化剂催化松香聚合反应工艺的研究

首次将3种硫酸-离子液体复合催化剂[H2SO4-(C2 mim)BF4、H2SO4-(C4 mim)BF4和H2SO4-(C8mim)BF4]用于催化松香聚合反应中,H2SO4-(C4 mim)BF4和H2SO4-(C8mim)BF4均显示出很好的催化活性.以H2SO4-(C8mim)BF4为代表,详细考察了不同溶剂、H2SO4用量、反应温度和反应时间等因素对反应结果的影响,得到较佳的工艺条件松香和甲苯质量比11,催化剂用量为松香质量的30%,反应温度70℃,反应时间4 h.在该条件下,得到的聚合产物软化点为135℃,酸值为142mg/g.并对H2SO4-(C8mim)BF4复合催化剂的重复使用性能进行了考察,该复合催化剂克服了传统催化剂的一些缺点,既简化了产物的分离,又可以重复使用.     

离子液体[HSO3-(CH2)4-mim][HSO4]催化合成松香甘油酯的研究

合成了1-磺酸丁基-3-甲基咪唑硫酸氢盐离子液体([HSO3-(CH2)4-mim][HSO4]),并以其为催化剂,催化松香和甘油酯化合成了松香甘油酯,用红外及核磁共振对产品进行了表征。详细探讨了各因素对酯化反应的影响,确定最佳反应条件为:醇酸比(nOH∶nCOOH)为1.1∶1,反应温度260℃,反应时间7 h,离子液体用量0.03%(占原料松香质量)。在此条件下,产品酸值9.6 mg/g,软化点90℃,得率100.2%,色泽(Fe-Co法)4,与传统催化剂ZnO相比,产品性能更佳。     

常压一锅法合成聚乙二醇400葡糖苷松香酸酯

常压下,以聚乙二醇400(PEG 400)、松香、淀粉为原料,对甲苯磺酸为催化剂一锅法合成了聚乙二醇400葡糖苷松香酸酯。最佳反应条件为:n(PEG 400)∶n(淀粉)∶n(松香)4.5∶1.5∶1,催化剂用量10%(以松香质量计),反应温度200℃,反应时间7 h。粗产品酸值低于5 mg/g,利用CaO精制后的产物酸值小于1 mg/g。红外光谱和元素分析表明得到的产物为目标产物。所合成的产物具有较好的乳化性能。     

松香基季铵盐双子表面活性剂的合成及分析

松香（酸值170．54mgKOH／g）与环氧氯丙烷反应,合成中间产物3-松香酰氧基-2-羟丙基氯,再与四甲基乙二胺反应,制备了松香基季铵盐双子表面活性剂（GSRP）;用FT—IR对产物结构进行了鉴定,并对其性能进行分析。研究结果表明：中间产物3-松香酰氧基-2-羟丙基氯的酯化率为99．18％;GSRP的合成反应条件为：摩尔比2.2：1（n中间产物：n-四甲基乙二胺）,温度85℃,时间20h,产物得率为76．70％,纯度为96．10％;GSRP的分水时间为16min;临界胶束浓度为1．42×10^-4mol／L,表面张力为36．69mN／m：发泡力为200mm。泡沫稳定性好。     

磺烷基咪唑磷酸盐-氯乙酸复合催化体系在α-蒎烯水合反应中的应用

制备了一种酸功能化离子液体1-(3-磺酸基)丙基-3-甲基咪唑磷酸二氢盐((HSO3-pmim) H2 PO4),并用FT-IR、 1 H NMR、 13 C NMR对其进行了表征.将其同氯乙酸构成的复合催化体系磺烷基咪唑磷酸盐-氯乙酸((HSO3-pmim)H2 PO4-ClCH2 COOH)用于催化α-蒎烯水合反应,详细考察了水合反应的影响因素,得到了较佳的反应条件:n(α-蒎烯)∶ n((HSO3-pmim)H2 PO4)∶ n(氯乙酸)∶ n(水) 6∶ 1∶ 6∶ 30,反应温度 80 ℃,反应时间 8 h.在该条件下α-蒎烯转化率为 97%,松油醇选择性 47.1%.并对催化体系的重复使用性进行了考察,该催化体系不经处理直接重复使用5次时,α-蒎烯转化率仍达 83.7%,松油醇选择性 51.6%.     

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.     

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.     

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.     

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.     

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。     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.