马来海松基环氧纳米复合材料的制备及性能研究

以松香为原料,通过Diels-Alder加成制备了马来海松酸酐(MPA),再经过酯化、闭环反应得到了马来海松基环氧树脂(MPA-ER),并用FT-IR和1 H NMR对MPA和MPA-ER的结构进行了表征.进一步将多壁碳纳米管(MWCNTs)与MPA-ER共混制备了一系列的MPA-ER/MWCNTs复合材料,对其力学性...     

马来海松酸三烯丙酯的制备与表征

【目的】通过Diels-Alder反应将马来酸酐引入松香结构单元,在微波辅助条件下在马来海松酸分子结构中引入含有3个活性碳碳双键的马来海松酸三烯丙酯,为我国松香基精细化学品的精深加工提供一条新路径。【方法】分别以水和乙醇为溶剂,通过中和反应制备马来海松酸钠盐,在微波辅助条件下,以N,N-二甲基甲酰胺为溶剂,以马来海松酸钠与氯丙烯为原料,通过相转移催化法制备马来海松酸三烯丙酯。基于FT-IR、GC及MS等手段对产物结构进行表征。【结果】确定优化反应条件为:微波功率400 W,反应温度55℃,反应时间4 h,氯丙烯与马来海松酸钠物质的量之比为3,催化剂用量5%,在此条件下产物的收率为93.2%。从色谱分析结果可以看出,反应进行比较彻底,原料峰已完全消失,而且生成的产物纯度较高,优化条件下所得产物GC含量为96.1%。红外光谱表征中红外特征吸收峰的消失和生成说明马来海松酸三烯丙酯3个羧基均发生了酯化反应,且反应较为彻底。质谱分析确认了以乙醇为溶剂制备的钠盐为原料所得的马来海松酸三烯丙酯的副产物经甲酯化后主要有马来松香酸酐单烯丙酯及马来松香酸二烯丙酯,以水为溶剂制备的钠盐为原料所得产物主要为马来海松酸三烯丙酯,副产物只有马来海松酸酐单烯丙酯。质谱分析中m/z 538为马来海松酸三烯丙酯的分子离子峰,m/z 481的碎片峰为[M-OCH_2CHCH_2]~+是脱去1分子酯基部分生成的峰,m/z 439的碎片峰为脱去酯基后形成的稳定的马来海松酸酐结构,质谱碎片峰m/z 342为马来海松酸三烯丙烯酯的质谱分裂逆Diels-Alder反应,碎片离子197的基峰是稳定的三环菲骨架结构。制备的马来海松酸三烯丙酯为白色黏稠液体,其酸值为2.5 mg·g~(-1),密度为1.109 7×10~3 kg·cm~(-3),黏度为8.5×10~3mPa·s。【结论】开发了具有3个活性双键的马来海松酸三烯丙酯聚合单体,以水为溶剂制备的钠盐为原料所得马来海松酸三烯丙酯的纯度较高。     

羟基保护法合成松香酰二乙醇胺及其表面活性初探

先用二氢吡喃保护二乙醇胺的羟基，与松香酸甲酯(RAME)反应制得松香酰二乙醇胺二(四氢吡喃醚)后，再经羟基解保护后制备松香酰二乙醇胺(RDEA)。二次回归正交试验优化的合成条件为：松香酸甲酯与二乙醇胺二(四氢吡喃醚)摩尔比1：1．6，反应温度93℃，反应时间4．4h，催化剂乙醇钠用量为二乙醇胺二(四氢吡喃醚)的2．5％，松香酰二乙醇胺得率为93．87％。性能测定表明，松香酰二乙醇胺的发泡能力及泡沫稳定性、乳化能力与十二烷基硫酸钠(K12)相当，临界胶束浓度较K12略大。松香甲酯化制备松香酸甲酯的最佳制备条件：松香与甲醇摩尔比1：3、反应时间1h、反应温度70℃、催化剂氢氧化钾用量为松香的2％，酯化率为95．50％。     

马来松香基双磺酰胺化合物的合成及杀菌活性初探

以马来松香为原料,经酰氯化、与N-芳磺酰基乙二胺类化合物的N-酰化反应,合成得到14个新型马来松香基双磺酰胺类化合物(4a~4n),其结构经FT-IR、1H NMR、13C NMR、ESI-MS、UV-Vis和元素分析进行表征。经鉴定,14个化合物分别为马来松香基双苯基磺酰胺(4a)、马来松香基双对甲苯基磺酰胺(4b)、马来松香基双间甲苯基磺酰胺(4c)、马来松香基双对甲氧基苯基磺酰胺(4d)、马来松香基双间甲氧基苯基磺酰胺(4e)、马来松香基双对溴苯基磺酰胺(4f)、马来松香基双间溴苯基磺酰胺(4g)、马来松香基双对氯苯基磺酰胺(4h)、马来松香基双间氯苯基磺酰胺(4i)、马来松香基双对氟苯基磺酰胺(4j)、马来松香基双邻氟苯基磺酰胺(4k)、马来松香基双对硝基苯基磺酰胺(4l)、马来松香基双间硝基苯基磺酰胺(4m)、马来松香基双邻硝基苯基磺酰胺(4n)。初步的生物活性测试表明,化合物4a~4n对5种供试植物病菌均有一定的杀菌活性,其中在50 mg/L质量浓度下,化合物4k对苹果轮纹病菌的抑制效果较好,抑制率最好为66.8%。     

萜烯马来酸酐催化加氢反应的研究

研究了反应温度、压力、催化剂用量等因素对萜烯马来酸酐催化加氢制备氢化萜烯马来酸酐合成工艺的影响.实验结果表明,采用钯碳催化萜烯马来酸酐加氢生成氢化萜烯马来酸酐的最佳反应条件为:反应温度150～160 ℃、氢气压力8～10 MPa、催化剂用量4 %～6 %.该催化氢化工艺具有催化效率高、选择性好、反应时间短等优点.     

马来酸乙基纤维素的制备与表征

为提高乙基纤维素的进一步应用,以乙基纤维素为原料,马来酸酐为衍生化试剂,制备了马来酸乙基纤维素,通过红外、核磁、X射线衍射、差示扫描量热(DSC)等手段对其结构及性质进行了表征,研究了反应各因素对产物取代度的影响,确定了马来酸乙基纤维素(ECMA)最佳反应条件为:马来酸酐与乙基纤维素中羟基总量物质的量之比为4:1,反应...     

固体超强酸SO42-/TiO2-ZrO2 催化β-月桂烯与马来酸酐的Diels-Alder反应研究

研究了SO42-/TiO2-ZrO2型固体超强酸催化剂的制备及其催化β-月桂烯与马来酸酐的Diels-Alder反应,通过GC、GC-MS和红外分析,确定其主产物为4-(4-甲基-3-戊烯基)-4-环己烯-1,2-酸酐。结果表明,该催化剂对β-月桂烯与马来酸酐的Diels-Alder反应有较高的催化活性和较好的选择性。考察了其催化性能的影响因素。结果表明,适宜的催化剂制备条件是:n(钛)∶n(锆)为1∶1,焙烧温度450℃。Diels-Alder反应优化的工艺条件:n(β-月桂烯)∶n(马来酸酐)为1∶1、反应时间4 h、反应温度60℃、催化剂用量1%。该条件下β-月桂烯转化率96.5%,产物选择性94.0%,产物得率90.7%。同时考察了催化剂放置时间对异构产物的影响和催化剂重复使用情况。     

超临界正己烷中松香酸一元醇酯高压氢解还原反应

在超临界正己烷条件下,采用Cu-Zn催化剂进行了系列松香酸一元醇酯的氢解还原反应。考察了反应条件对反应结果的影响。结果表明:适宜的工艺条件为松香酯15 g,Cu-Zn催化剂用量为松香酯质量的10%,m(松香酯)∶m(正己烷)为1∶3,温度为270℃,压力10 MPa,反应时间11 h;该条件下松香甲酯、松香丁酯和松香辛酯的转化率分别为87.9%,75.0%和69.9%,选择性分别为93.4%,92.4%和92.8%,得率分别为82.1%,69.3%和64.9%;FT-IR和GC-MS分析结果表明,松香酯经氢解还原反应后酯基被还原为羟基,还原产物主要成分为二氢海松醇、二氢枞醇、四氢枞醇和脱氢枞醇等。     

二元端乙烯基型松香衍生物的微波辅助制备及表征

以丙烯酸改性松香酸钠和氯丙烯为原料,十六烷基三甲基溴化铵为催化剂,对苯二酚为阻聚剂(用量为丙烯酸改性松香钠质量的0.2%),N,N-二甲基甲酰胺为溶剂(用量为丙烯酸改性松香钠质量的3倍),在微波辅助条件下,探讨了工艺条件对二元端乙烯基型松香衍生物丙烯酸改性松香烯丙酯得率的影响,确定了最佳工艺条件为:微波功率400 W,反应时间100 min,催化剂用量4%,物料配比n(氯丙烯)∶n(丙烯酸改性松香钠)2∶1,反应温度50℃,在此条件下产物得率高达92.2%。采用GC、GC-MS和FT-IR等技术表征了反应产物的结构,结果表明合成产物结构与目标产物结构一致。     

用磷钼酸催化合成马来海松酸反应的研究

以杂多酸磷钼酸为催化剂合成了马来海松酸.考察了催化剂用量、溶剂、反应时间及原料配比等对双烯加成反应的影响.实验结果表明,松香与马来酸酐摩尔比为1.7∶1,催化剂质量分数为2.0 %,甲苯作溶剂,反应时间4 h,反应得率可达78.9 %.     

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.