仙鹤草多糖的提取及部分理化性质

以多糖提取率为指标,采用L9（3^4）正交实验设计对仙鹤草多糖的提取工艺条件进行优化,并采用脱蛋白与DE-52纤维素离子交换柱层析法对仙鹤草多糖进一步分离纯化．同时对多搪的性质进行分析鉴定。实验结果表明,仙鹤草多糖的最佳提取工艺为：浸提温度为80℃,浸提时间12h,料液比1：15．在此条件下仙鹤草多糖提取率为2．15％,浸提温度是影响得率的主要因素。纯化后的仙鹤草多糖组分HAPI、HAPII多糖含量分别为70．08％、78．80％。     

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。     

中压柱层析法分离白藜芦醇的研究

对虎杖(Polygonum cuspidatum Sieb．et Zucc．)中的白藜芦醇进行了提取分离和含量测定。考察了浸提温度、浸提液浓度、浸提时间和次数、料液比等5个因素对白藜芦醇提取的影响，确立了白藜芦醇最佳提取条件为：浸提液体积分数为95％，浸提温度60℃，料液比11:1，回流提取3次，每次60min。采用中压硅胶柱层析法分离白藜芦醇，产物经重结晶后用高效液相色谱测定含量达99．28％。结果表明所建立的制备及分离纯化工艺可用于白藜芦醇的生产。     

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900 W,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7 min,料液比1:30.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.     

正交试验法优选低聚原花青素的提取工艺

对落叶松树皮中的低聚原花青素进行了提取分离和含量测定。考察了浸提温度、浸提时间、浸提次数、液料比等4个因素对低聚原花青素提取的影响，确立了低聚原花青素最佳提取条件为：以水为提取剂，在85℃、液料比10：1的条件下保温浸提2h。提取物经醇沉后，用石油醚沉淀法分离低聚原花青素，产物经正丁醇一盐酸法显色，比色法测定质量含量可达90％以上。     

地榆根提取低聚原花青素的研究

对吉林地区野生地榆根低聚原花青素（OPC）进行了提取分离工艺研究。考察了溶剂体积分数、原料粒度、料液比、浸提温度、浸提时间、浸提次数等6个因素对地榆根提取低聚原花青素得率的影响，确立了较佳提取条件为：以体积分数60％乙醇水溶液为提取剂、原料粒度为0．25-0．42mm、料液比1：12（g：mL）、浸提温度50℃、浸提4次、每次1h。浸提浓缩液加入一定量饱和NaCl溶液，低温离心过滤后，用2倍体积乙酸乙酯萃取3次，得到纯化后提取物中OPC质量分数达到56．86％，OPC得率为绝千原料的3.42％。     

滨州市沾化冬枣核中活性多糖的提取

利用沾化冬枣核为试验材料,进行了冬枣核多糖的提取分离研究。通过单因素试验确定冬枣核中多糖的含量,进一步通过正交试验确定了多糖的较优提取条件。结果表明:各因素对枣核多糖提取效果的影响程度从高到低依次为浸提温度浸提时间料液比。综合考虑提取效果与生产成本,对提取条件进行优化,确定了适宜的提取条件:料液比1∶20、浸提温度90℃、浸提时间4h。以期为冬枣的综合加工利用、为从废弃植物材料中提取生物活性成分提供参考。     

辽南山葡萄籽多酚提取工艺的初步研究

以山葡萄籽为实验材料，通过单因素法提取葡萄籽中的多酚。根据不同浸提剂在540nm处可见光吸收情况的测定，确定70％甲醇溶液为最佳浸提剂。通过单因素试验确定了提取剂浓度、提取时间、提取温度、料液比的适用范围，再利用正交试验法进行工艺优化。确定最佳工艺条件为：体积分数70％的甲醇，料液比1：20（m／v），70℃水浴，浸提20min。山葡萄籽中多酚的含量可达18．981mg／g。     

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。     

“青引”燕麦中皂甙提取工艺研究

研究利用索氏浸提法提取燕麦中皂甙工艺条件。以乙醇-正丁醇为溶剂,以皂甙RC为标准品,采用分光光度法定量分析燕麦提取液中总皂甙含量,采用正交试验对料液比、乙醇浓度、浸提温度对提取率的影响。结果表明,正交试验最佳提取条件为料液比：1∶7;乙醇浓度：70%;浸提温度：70℃,提取率为1.716%;主次顺序依次为：料液比〉浸提温度〉乙醇浓度。该方法操作方便,简单易行,具有推广应用价值。     

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.