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:5 g板栗壳粉在微波辐照时间13 min、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.     

响应面法对板栗壳色素的超声辅助提取工艺优化研究

以NH4OH水溶液为溶剂,采用响应面法对超声波辅助提取板栗壳色素的工艺条件进行了优化。采用中心复合实验设计,进行了不同NH4OH浓度、液料比和浸提时间对色素粗提物得率和色价影响的响应面分析实验。结果表明,所得二次回归模型对实验数据有较好的拟合效果;以色素粗提物得率为考察指标的优化提取条件为,NH4OH浓度为1.1 mol/L,液料比为16.5 mL/g,提取时间为120 min;以色价为考察指标优化提取条件为,NH4OH浓度为0.7 mol/L,液料比为14.6 mL/g,提取时间为112 min。板栗壳色素在生产中采用以色价为考察指标的优化提取工艺为宜。     

应用微波技术提取紫荆花色素的研究

研究了应用微波技术从植物紫荆(Cercis chinensis Bunge)的花中提取色素的新工艺并确定了最佳工艺条件：原料0．2000g紫荆干花，提取剂95％乙醇，料液比1：50(g：mL)，微波功率648w，提取时间30s，提取次数2次。最佳工艺条件下色素的提取率为92．1％，产率为9．48％，色价E(1％，549nm)为22．3。与溶剂浸提法相比，微波法提取紫荆花色素的每次提取时间由24h减小为30s，提取率从90．2％增加到92．1％。     

石斛兰色素的提取及稳定性研究

对石斛兰色素提取的最佳方法以及稳定性的研究结果表明：石斛兰色素的最大吸收波长为545nm;提取最佳条件组合为：提取温度50℃,提取时间2h,提取浓度50%乙醇溶液,料液比为1∶5;色素在pH值为4左右较稳定,碳水化合物对色素有保护作用,金属离子Fe2＋、有机酸、氧化剂H2O2和还原剂Na2SO3均对色素有破坏作用。     

板栗壳中多酚的提取及体外抗氧化性研究

研究了不同因素对板栗壳多酚提取效果的影响,并对不同条件下板栗壳多酚的抗氧化性进行了研究。结果表明,板栗壳多酚的最佳提取条件为:乙醇体积分数59.7%,料液比1∶18(g∶mL),浸提温度52.6℃,浸提次数3次。在此最优工艺条件下板栗壳多酚提取得率预测值为76.0 mg/g,实验值75.9 mg/g。板栗壳多酚具有较强的清除自由基能力,在25~200 mg/L范围内,随质量浓度升高其还原能力和清除二苯基苦基肼自由基(DPPH.)、羟基自由基(.OH)、超氧阴离子自由基(O-2.)的能力逐渐增强,当200 mg/L时其还原能力达0.841,DPPH.抑制率达89.7%,均高于同质量浓度的2,6二-叔丁基对甲酚(BHT),但低于同质量浓度Vc,对O-2.和.OH的清除率分别为93.2%和94.0%,均高于同质量浓度BHT和Vc。     

真丝织物板栗壳媒染工艺的优化与蜡染产品的开发

以天然板栗壳色素为染料,选用硫酸铝钾、硫酸亚铁、硫酸铜和壳聚糖4种媒染剂,对真丝织物进行媒染染色,测量染色试样的K/S值、⊿E值、摩擦牢度和耐洗牢度,确定硫酸亚铁为最佳媒染剂。通过正交实验分析,确定了板栗壳染料用于真丝织物媒染染色的最佳工艺条件,并利用该方法开发了板栗壳染料蜡染产品。结果表明:板栗壳染料适合于真丝织物的染色。     

萃取法提取洋葱中类黄酮的研究

以市售鲜洋葱为原料，乙醇为萃取溶剂，对洋葱中的类黄酮进行提取，分别探讨了提取时间、提取温度和固液比3个单因素条件对洋葱中类黄酮提取率的影响，并结合单因素实验结果进行了正交实验，以此得出了最佳提取条件。实验结果表明：乙醇的体积分数为95％时，洋葱中黄酮类化合物的最佳提取条件为：提取时间4h ，固液比为1∶1．5（g/mL ），提取温度为40℃，在此条件下洋葱中黄酮类化合物的提取率为0.0137％。     

红地球葡萄皮色素的提取及其稳定性的影响因素

以新鲜红地球葡萄为原料,探讨其天然色素的提取工艺,并通过正交实验得出了红地球葡萄色素的最佳提取工艺条件:80%的乙醇作提取剂,pH值为3,提取温度为70℃,料液比为1∶9。并对红地球葡萄色素的稳定性进行了研究,结果表明:红地球葡萄色素在pH为2~6时相对稳定,耐热性较好,耐光性也较好;金属离子对色素稳定性有一定的影响,其中Cu2 、Fe3 、Fe2 对色素的色泽有较大的破坏作用,但M g2 对红地球葡萄色素有稳定作用;氧化剂H2O2和还原剂N a2SO4对色素有一定的破坏作用。     

橡子壳色素的研究

报道了从橡子壳中提取、分离天然色素的方法，分析其化学结构，研究其结构的稳定性和毒性。     

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。     

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。     

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.     

Key Habitats in the Norwegian Production Forest: A Case Study

This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes.