SO2-4-Al-MCM-41的合成、表征及对松油醇酯化的催化作用

通过水热合成法合成出中孔分子筛Al-MCM-41.合成条件晶化温度145 ℃,晶化时间24～28 h.用不同方法处理Al-MCM-41得到SO2-4-Al-MCM-41.通过XRD、BET和FT-IR对SO2-4-Al-MCM-41进行表征.结果表明分子筛的骨架没有被破坏,结晶度较好.从FT-IR图上看出SO2-4已进入分子筛骨架内部.将SO2-4-Al-MCM-41用于催化松油醇酯化反应.气相色谱分析反应结果表明,用0.25 mol/L H2SO4浸泡焙烧过的Al-MCM-41得到的SO2-4-Al-MCM-41催化活性最好.     

含锆中孔分子筛SO4^2-／Zr-MCM-41催化松节油水合反应

合成了SO4^2-促进的含锆中孔分子筛SO4^2-／Zr-MCM-41(孔径4．1nm)，通过XRD及FT-IR表征了其结构。结果表明：SO4^2-／Zr-MCM-41存在中孔分子筛的特征吸收峰，具有良好的长程有序性和结晶度；SO4^2-与骨架原子形成了化学键，并增强了其酸性，Ho≤-12．76。将SO4^2-／Zr-MCM-41用于催化松节油的水合反应，获得了较适宜的反应条件：催化剂用量为松节油质量的7．5％，氯乙酸、松节油及水的摩尔比为1：1：3，反应温度60℃，反应时间8～10h。在上述条件下，松油醇的含量达到60％。     

催化α-蒎烯聚合

制备了中孔A1系和Zr系分子筛，用H2SO4和H3BO3处理中孔分子筛(MCM-41)分别得到强酸性SO4^2-／A1-MCM-41、SO4^2-／Zr-MCM-41、BO3^3-／A1-MCM-41及BO3^3-／Zr-MCM-41中孔分子筛催化剂。XRD、FT-IR及Hammet，指示剂测试结果表明：这些中孔分子筛具有一定的长程有序性，结晶较好；强酸基团已进入MCM-41骨架内部，并与骨架原子形成了化学健，从而产生强酸中心；H0值小于-12.76，具有超强酸性。以它们为载体，负载A1C13制成复合催化剂，催化α-蒎烯聚合，考察了载体种类、负载量及溶剂极性对α-蒎烯聚合的影响。     

/Zr-MCM-41催化松节油水合反应

合成了SO2-4促进的含锆中孔分子筛SO2-4/Zr-MCM-41(孔径4.1 nm),通过XRD及FT-IR表征了其结构.结果表明:SO2-4/Zr-MCM-41存在中孔分子筛的特征吸收峰,具有良好的长程有序性和结晶度;SO2-4与骨架原子形成了化学键,并增强了其酸性,H0≤-12.76.将SO2-4/ Zr-MCM-41用于催化松节油的水合反应,获得了较适宜的反应条件:催化剂用量为松节油质量的7.5 %,氯乙酸、松节油及水的摩尔比为1∶1∶3,反应温度60 ℃,反应时间8～10 h.在上述条件下,松油醇的含量达到60 %.     

固体酸SO42-/Al-MCM-41催化木糖制糠醛的研究

采用硫酸对Al-MCM-41固体酸进行改性,制备木糖脱水制糠醛催化剂SO42-/Al-MCM-41.借助傅里叶变换红外光谱(FT-IR)、氨气程序升温脱附(NH3-TPD)、氮气等温吸附-脱附分析等表征技术对催化剂进行表征.结果表明,硫酸改性成功地在分子筛Al-MCM-41表面引入了SO42-,提高了分子筛的酸性,并且...     

固体超强酸SO4^2-／TiO2在α-蒎烯合成紫苏葶中的应用研究

筛选出了用α-蒎烯三步法合成制紫苏葶的一种新型催化剂SO4^2-／TiO2型固体超强酸，得到催化剂制备的最适工艺条件为：硫酸浓度0．5mol／L、催化剂焙烧温度300℃、焙烧时间3h。用上述条件制备的催化剂催化桃金娘烯醛异构化制紫苏醛，得到最适工艺条件为：反应温度400℃、反应压力28kPa、空气流速12h^-1。桃金娘烯醛的最高转化率达87．45％，紫苏醛的收率达41．29％，三步反应总转化率为33．49％。用IR、程序升温脱附（TPD）和BET比表面积对催化剂进行了表征，并将催化剂特性与它们的催化性能相关联。实验结果表明：SO4^2-／TiO2固体超强酸催化剂表面形成螯合配位；该催化剂的活性随其比表面积和总酸量的增加而增大。     

磁性纳米固体超强酸的制备及合成松香甘油酯的研究

采用溶胶-凝胶法制备了磁性纳米固体超强酸SO4^2-/TiO2-Fe3O4,以松香甘油酯的合成为目标反应，探讨了制备条件对SO4^2-/TiO2-Fe3O4催化剂酯化性能的影响。得出最佳制备条件为：Ti与Fe的摩尔比为30：1,用浓度为1．5mol/L的H2SO4浸泡．在450℃下焙烧3h。并采用IR、TEM等分析手段对该催化剂结构进行了表征．用改进的Hammett指示剂法测定了催化剂的酸强度。     

7—异丙基—4—甲基—1—Yu甲醇的简单甲基化反应及其产物性质研究

研究了新化合物7-异丙基-1-甲氧甲基-4-甲基Yu（1）的合成方法及其物理化学性质。通过7-异丙基-4-甲基-1-Yu甲醇（2）与甲醇之间的简单醚化反应即可能制得化合物1，比学会醚化的反应条件温和而简单易行，仅用乙醚溶剂、无机酸催化剂和0-5℃的反应温度，在数分钟内即可完成反应。反应还生成二聚体化合物（5）及其它少量多聚体副产物。经过^1H NMR，FTIR，UV-vis，HR-MS等波谱分析证实了新化合物1和5的化学结构。     

MCM-41分子筛膜的制备、改性及其在酯交换反应中的应用

采用原位水热合成法在氧化铝陶瓷膜(CM)表面原位合成出了孔道规则有序的MCM-41/CM分子筛膜。再采用浸渍法将SO2-4/Zr O2负载在MCM-41/CM分子筛膜上对MCM-41进行酸改性,制得负载型固体酸催化剂SO2-4/Zr O2/MCM-41/CM,并用于催化棕榈油与甲醇的酯交换反应制备生物柴油。结果表明,当Zr(NO3)4的浓度为0.4 mol/L、硫酸浓度为2 mol/L、焙烧温度为550℃时,制备出的负载型固体酸催化剂SO2-4/Zr O2/MCM-41/CM活性最高。通过考察反应条件对酯交换反应的影响,得出最佳的反应条件,即当催化剂用量5%(以活性组分负载率计)、反应时间为60 min、反应温度为100℃、醇油物质的量之比为10∶1时,脂肪酸甲酯的收率可达92%以上,重复使用5次后,脂肪酸甲酯收率仍达80%以上。     

乙酸诺卜酯的合成及其氧化反应的研究

由β-蒎烯合成诺卜醇，再由诺卜醇合成乙酸诺卜酯，产率分别为61．4％和84．4％。用二氧化铬酸性水溶液氧化乙酸诺卜酯，分离得到两个产物的纯品，经IR、MS、^1HNMR和^13C NMR分析后，确定为4-(1-甲基-1-羟基乙基)-1-环己烯-1-乙醇乙酸酯和4-(1-甲基-1-羟基乙基)-1-环己烯-1-乙醇。前者的GC含量占反应产物的50％～60％，是反应的主要产物，它是乙酸诺卜酯的四元环开裂后，再发生水合的产物，后者则由前者水解而来。通过GC-MS分析确定了反应产物中其他几个GC含量相对较高的组分，主要包括三组异构体，分别是2，3-环氧诺卜乙酸酯、1-羟基-2，3-环氧诺卜乙酸酯和5-羟基-2，3-环氧诺卜乙酸酯。对反应产物的分析结果表明：反应主要是四元环开裂，并进一步水合，另外伴有少量双键环氧化的产物，这些环氧化的产物还可进-步在C-1和C-5处发生叔氢氧化。     

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.