微波辐照提取板栗壳棕色素的研究

以板栗壳为原料，在微波条件下，以乙醇溶液作溶剂直接从板栗壳中提取天然棕色素。探讨了各因素对板栗壳天然色素提取效果的影响。确定了在微波条件下从板栗壳中提取天然色素的最佳工艺条件：5g板栗壳粉在微波辐照时间13min、浸提温度75℃、乙醇溶液的体积分数40％、料液比1：20（g：mL）的条件下得率为7.02％。通过对色素的定性实验和稳定性实验，表明该板栗壳色素属于黄酮类色素，其对光照、温度、还原剂、氧化剂、pH值有良好的稳定性。     

超声波提取乌饭树叶色素及其稳定性的研究

在单因素试验的基础上,用正交试验法确定了超声波法提取乌饭树叶色素的最佳工艺条件。结果为：室温下,超声波频率30kHz,浸提时间10min,溶剂为62％（体积分数）乙醇,液固比为3．5：1（mL：g）,浸提1次。超声波提取法与常规提取法相比有明显的优势,在各自的最佳工艺条件下,常规法提取率为11．43％,而超声波法为23．84％,且所用溶剂少,提取时间短,所得色素品质更高。此外对色素的稳定性进行了实验。乌饭树叶色素在酸性条件及低于80oc时是稳定的;蔗糖对色素的降解作用不明显,而柠檬酸具有明显的增色和护色作用;当苯甲酸钠和山梨酸钾的质量分数高于0．01％时对色素有明显的降解作用。     

不同工艺提取栀子黄色素的比较研究

比较研究了热提取、超声波提取、微波提取3种不同工艺对栀子黄色素提取效果的影响。热浸提正交试验的最佳工艺条件：70％的乙醇（体积分数，下同）提取1．5h，提取温度30℃，料液比1：25（g：mL，下同），产品的色价为66．45。超声波提取正交试验的最佳工艺条件：80％的乙醇提取20min，料液比1：20，产品的色价为87．77。微波提取单因素试验的最佳工艺条件：提取功率800W，用50％乙醇提取30min，提取温度50℃，料液比1：5，色价为64．14。结果表明：热浸提、超声波提取、微波提取3种方法提取栀子黄色素的色价明显不同，超声波提取的效果最好。     

超声波提取大花葵色素的工艺研究

大花葵(Malva sylvestris L.var.mauritiana Miller)为锦葵科锦葵属一年生草本植物，结花量大，花中含有大量的红色素，是一种重要的天然色素资源，可广泛应用于食品、制药、化妆品等行业。大花葵色素属于花青苷类色素，常规提取工艺容易使其发生降解、褪色。超声波提取技术具有时间短、效率高、提取量高等特点，同时可防止提取物在长时间、高温条件下发生降解、褪色等变化。作者对超声波提取大花葵色素的各项工艺条件进行了初步探讨，设计了工艺流程，研究了超声波提取的温度、时间和提取剂对色素提取率的影响，得出最佳提取工艺参数为：在超声波频率为30kHz条件下，用质量分数为2％的稀H2SO4作提取剂，处理40min，温度50℃时提取率最高。     

微波法提取黑木耳凝胶的工艺研究

黑木耳中含大量的由多糖及蛋白质等物质组成的木耳凝胶，对人体有重要的生理功能。利用微波法提取黑木耳凝胶，找出了最佳提取工艺条件。实验结果表明：当颗粒度为1．46mm，固液比为1：30，时间为8min，功率为640W时，黑木耳凝胶的提取率达到30％以上。     

微波辅助法提取印楝素的研究

介绍了一种有效利用微波辅助从印楝(Azadirachta indica A.Juss)种仁中提取印楝素的方法。通过考察辐射时间、溶剂、物料比以及辐射功率等因素对提取率的影响，得出结论为：预处理过的印楝种仁粉末6.65g(相当于印楝种仁10g)，以甲醇做溶剂、微波功率210w、物料比1：3(g／mL)、辐射时间为3min*3次，提取率最高。与传统的磁搅拌法相比，该方法不仅工艺简单，而且可以提高产率，缩短提取时间。用高压液相法定量地测定了所提取印楝素的含量，其提取率可达0．519％．     

微波法提取木材中的阿拉伯半乳聚糖

以兴安落叶松(Larix gmelinii Rupr．)木材的加工剩余物为原料,利用微波效应,以水为溶剂来提取其中的阿拉伯半乳聚糖。通过实验设计考察了微波提取的条件即微波功率、作用时间、木粉粒度、料液比等因素对提取物产率的影响,从而确定较佳的提取工艺：微波功率为490w,作用时间为25min,料液比为l：35,木粉粒度为0．20—0．30min。微波提取法提取物产率可以达到17．47％。并在此基础上将微波提取方法与传统提取方法进行分析比较得出：微波提取法的提取率比传统水浴提取法的提取率高出1．6％,在所用时间上仅用了l／12,同时利用红外光谱对提取物进行了分析。     

微波辅助提取兴安落叶松木材中阿拉伯半乳聚糖的工艺研究

以兴安落叶松(Larix gmelinii Rupr．)木材的加工剩余物为原料．以水为溶剂，微波辅助提取阿拉伯半乳聚糖。通过对影响提取率的主要因素微波作用时间、做波功率、料液比和木粉粒度等进行正交试验．分析得出微波辅助提取阿拉伯半乳聚糖的较佳工艺参数为10．0g兴安落叶松木粉。微波功率210W。微波作用时间35min。料液质量比1：35．木粉粒度0．2～0．3mm时．阿拉伯半乳聚糖提取率17．47％。比传统水浴浸提法高1．6％，时间仅为原来的1/10。用红外和紫外光谱分析两种方法所得产物的化学结构相同。微波辅助提取的粗糖中杂质含量比传统水浴法低。实验结果表明．对于兴安落叶松木材中阿拉伯半乳聚糖的提取．微波辅助提取优于传统水浴浸提法。     

微波辅助提取桔皮中天然抗氧化剂的研究

以桔皮为原料，乙醇为溶剂，在微波功率900W，提取温度75℃条件下，通过单因素试验探讨了乙醇体积分数、浸提时间、料液比对总黄酮提取率的影响，并通过正交试验对桔皮中黄酮类化合物提取工艺进行了研究。结果表明，用微波法从桔皮中提取总黄酮的最佳工艺条件为：乙醇体积分数75％，浸提时间7min，料液比l：30。用此工艺提取的总黄酮得率为12．04％。通过1,1-二苯基-2-苦基肼（DPPH）法测定不同工艺条件下桔皮提取物的抗氧化性能，表明不同工艺的桔皮提取物均有一定的清除DPPH自由基的能力，其清除率与总黄酮的含量有一定的量效关系。     

优化喜树果中喜树碱和10-羟基喜树碱的匀浆提取工艺

采用匀浆提取的方法从喜树果中提取喜树碱和10-羟基喜树碱，考察乙醇体积分数、匀浆时间和液料比等因素对提取率和纯度的影响，并通过响应面法进行工艺优化，分别得到以喜树碱、10-羟基喜树碱的提取率和纯度为响应值的回归方程，进而获得最佳工艺条件为乙醇体积分数52．41％；匀浆时间2．93min；液料比11．11（mL：g）。最佳条件下的验证实验表明：喜树碱提取率为0．0923％，浸膏中喜树碱的纯度为1．0633％，与模型值相对偏差分别为0．75％和0．88％；10-羟基喜树碱提取率为0．0094％，浸膏中10-羟基喜树碱的纯度为0．1078％，与模型值相对偏差分别为0．53％和0．78％，说明回归方程可以很好地预测实验结果。     

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.