氧对亚硫酸盐制浆废液戊糖、己糖同步酒精发酵的影响

研究了氧对休哈塔假丝酵母Ｒ的戊糖酒精发酵的影响。休哈塔假丝酵母Ｒ的戊糖酒精发酵需在“限制性供氧”条件下进行,溶解氧浓度在０９～１１ｍｇ／Ｌ时,木糖利用率和酒精得率分别为８３８％～９３５％和８８４％～９１２％;在１５Ｌ发酵罐中发酵富含戊糖的亚硫酸盐制浆废液３２ｈ,糖利用率和酒精得率分别达９２５％和８５０％,酵母细胞吸氧速率为１２４～１．４８ｍｍｏｌ／Ｌ·ｈ,溶氧系数ＫＬａ值１４７５～１８００ｈ－１;当通风量为４ｍ３／ｈ时,在５ｍ３发酵罐中发酵还原物为２２９０ｇ／Ｌ的亚硫酸盐制浆废液２２ｈ,还原物降至５９ｇ／Ｌ,醪液酒精浓度达０７４％（ｖ／ｖ）,通风量过高或过低均导致酒精得率的下降。     

耐温酵母TY01—15突变株的诱变育种及其研究

以热带假丝酵母ＴＹ０１为出发菌株，经多次的物理、化学诱变及传代驯育，采用一种简便而快速的筛选方法，筛选到一株适合于水解液发酵用的耐温突变酵母ＴＹ０１－１５。该突变株在添加营养盐（ＮＨ４）２ＳＯ４０．３％、ＫＨ２ＰＯ４０．１５％、ＭｇＳＯ４０．１％）、ｐＨ４～５、给予较大的通气量、３７℃条件下正常发酵，其菌体得率达到０．４１ｇ／ｇ，是出发菌株菌体得率（３７℃）的４倍，相当于理论得率的９０％左右，其蛋     

高寒地区地被菊组培苗移栽成活率研究

本文通过对地被菊组织培养苗出瓶移栽成活率进行多次试验性研究，结果表明：地被菊组培苗在高寒地区进行移栽，其根系发生状况是提高组培苗移栽成活性的关键。其最适生根培养基为１／２ＭＳ＋６－ＢＡ０．１ｍｇ／Ｌ（激素单位，下同）＋ＮＡＡ０．１＋糖３０ｇ／Ｌ＋琼脂５ｇ／Ｌ。移栽成活率可达８７％以上。     

菠萝果皮蛋白酶的活性研究

用丹宁沉淀法提取菠萝果皮蛋白酶，须经过多次洗涤、保护和激活，使酶从其复合物中游离出来。研究结果测得干酶得率约０．１７％，皮汁酶活性一般为０．０４万／ｇ，干酶活性约２０万／ｇ，果皮蛋白酶酶促反应最适条件为：ｐＨ５．５－６．５，温度≤６０℃。在一般室温下，酶促反应达到最大速度时间，鲜汁约１ｈ，干酶约需１ｈ－１．５ｈ。     

耐温酵母TY01－15突变株的诱变育种及其研究

以热带假丝酵母ＴＹ０１为出发菌株，经多次的物理、化学诱变及传代驯育。采用一种简便而快速的筛选方法，筛选到一株适合于水解液发酵用的耐温突变酵母ＴＹ０１－１５。该突变株在添加营养盐（（ＮＨ＿４）＿２ＳＯ＿４０．３％、ＫＨ＿２ＰＯ＿４０．１５％、ＭｇＳＯ＿４０．１％）、ＰＨ４～５、给予较大的通气量、３７℃条件下正常发酵，其菌体得率达到０．４１ｇ／ｇ，是出发菌株菌体得率（３７℃）的４倍，相当于理论得率的９０％左右，其蛋白质含量为４２％。     

马尖相思离体培养再生植株的研究

用马尖相思（Ａｃａｃｉａ ｍ ａｎｇｉｕｍ ）１０ 年龄树芽器官为外植体,通过组织培养直接诱导不定芽产生,并获得根茎叶齐全的试管苗。剪取当年枝条的自顶芽往下依次带节的茎段培养,以第二、第三节茎段诱导芽萌动率高而快;芽诱导培养基为改良ＭＳ＋ ６－ＢＡ ２ ｍ ｇ／Ｌ＋ ＮＡＡ ０．５ ｍ ｇ／Ｌ,芽诱导率９０％ ;芽增殖培养基为改良ＭＳ＋ ６－ＢＡ ０．５ ｍ ｇ／Ｌ＋ ＮＡＡ ０．２５ ｍ ｇ／Ｌ＋ ＶＢ２ ５ ｍ ｇ／Ｌ＋ Ｖｃ ４ ｍ ｇ／Ｌ,芽增殖倍数４．８ 倍;生根培养基为１／２ ＭＳ＋ ＡＢＴ ２ ｍ ｇ／Ｌ＋ ＩＢＡ ０．２ ｍ ｇ／Ｌ＋Ａｃ ０．１％ ,生根率９７．０％ ;黄心土为试管苗最佳移栽基质,成活率达到８５％ 。     

固定化休哈塔假丝酵母细胞发酵玉米秆水解液的研究

采用海藻酸钙凝胶将低浓度的休哈塔假丝酵母细胞包埋固定后，进一步通过增殖培养，使细胞密集在凝胶珠的表层，可以减小营养基质、氧气以发酵产物的传递阻力，有利用该菌的“半好气”酒精发酵。试验中发现，在凝胶中掺入适量氧化铝能明显增加固定化小珠的机械强度及使用寿命。固定化休哈塔假丝酵母细胞能够利用己糖和戊糖，８０ｇ／Ｌ的混合糖（己糖与戊糖１：１）经１２ｈ发酵，糖的利用率达９０．５％，而相同条件下游离细胞发酵需     

核桃离体胚的培养

本实验采用核桃成熟种胚的上胚轴以上部分为试材,采用不同的表面灭菌处理、基本培养基和生长调节物质浓度,研究各种处理对核桃离体胚生长发育的影响。结果表明：（１）未经表面灭菌处理的处植体生长发育明显优于经表面灭菌处理的外植体;（２）６－ ＢＡ有削弱顶端优势的作用,浓度越高,强度越大;（３）诱导顶芽、侧芽和丛生芽生长的适宜培养基配方和培养条件为：启动培养基１／４ ＭＳ＋ ０．５ ｍ ｇ／Ｌ ＢＡ 或１／２ ＭＳ＋ １．０ ｍ ｇ／ＬＢＡ,待外植体萌发后分别转入１／２ ＭＳ＋ ０．５ ｍ ｇ／Ｌ ＢＡ 或１／２ ＭＳ＋ １．０ ｍ ｇ／Ｌ ＢＡ,待材料进一步发育后分别转入ＭＳ＋ ０．５ ｍ ｇ／ＬＢＡ 或ＭＳ＋ １．０ ｍ ｇ／ＬＢＡ,以上各种培养基均含３０ ｇ／Ｌ蔗糖和７ｇ／Ｌ琼脂,ｐＨ５．８,培养条件为温度２５℃,光照１６ 小时／天,光强约２ ０００ Ｌｕｘ;（４）在无激素１／４ ＭＳ培养基上,具有一定大小的材料可形成不定根,说明低浓度无激素培养基适于核桃离体胚培养物的生根。     

蓝桉组织培养的研究

用蓝桉（Ｅｕｃａｌｙｐｔｕｓｇｌｏｂｕｌｕｓ）离体芽器官诱导培养，分化形成丛生芽，年繁殖系数３￣（１２）。０．１～０．５ｍｇ／Ｌ的６－ＢＡ或０．５～０．８ｍｇ／Ｌ的ＫＴ诱导外植体（带节茎段）腋芽萌动的效果最佳，诱导率分别达８０．３％和８１．５％。１．５～２０ｍｇ／Ｌ的６～ＢＡ或２０～２．５ｍｇ／Ｌ的ＫＴ分别与０．５～１．０ｍｇ／Ｌ的ＮＡＡ组合，对于促进腋芽分化形成丛生芽及继代培养中芽的增殖具有最佳效果。培养基中的无机盐浓度、蔗糖含量对蓝桉试管苗的生根具有显著影响；ＩＢＡ促进蓝桉试管苗的生根。至目前为止，在１／２ＭＳ无机盐培养基＋ＩＢＡ１．２～１．４ｍｇ／Ｌ＋Ｓ５ｇ／Ｌ中诱导生根，生根率最高可达２６．４％。     

分批添料纤维素酶水解研究

提出了在反应过程中分批添加底物的纤维素酶解方法，并对分批添料的作用机理进行了讨论。研究表明，分批添料可以同时提高酶解得率、底物浓度和酶解糖液浓度，当底物浓度为１５％（ｗ／ｖ）时，分批添料酶解得率为７０％，糖液中还原糖浓度为４８．１ｇ／Ｌ。     

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.