山药枸杞复合饮料的研制

对山药的热烫条件、复合饮料配方及稳定性进行了研究.结果表明:山药热烫的最佳温度为(100±1)℃,时间1.00 min.饮料的最佳配方为山药浆30.00%、枸杞汁20.00%、蔗糖6.00%、柠檬酸0.10%.复合稳定剂的最佳组合为黄原胶0.03%、羧甲基纤维素钠0.07%、海藻酸钠0.05%.     

低脂松仁蛋白饮料的研制

以松仁粕为主要原料,白砂糖、脱脂奶粉等为辅料,调制而成的低脂松仁蛋白饮料。在单因素的基础上通过正交实验,优化产品配方。结果表明:饮料最佳配比为松仁粕11%,脱脂奶粉4%,白砂糖3.5%,蔗糖酯为0.05%,最佳稳定剂CMC-Na与黄原胶质量比1∶2,总用量为0.09%(m/v)。该工艺下获得的产品口感适宜,风味独特,组织状态均匀。     

野生蓝莓果浆型饮料加工工艺研究

以黑龙江大兴安岭野生蓝莓为试材,经蒸果、研磨、过滤、调配、灭菌、喷淋等过程制作野生蓝莓果浆型饮料。对饮料的原汁含量,白砂糖含量,纯净水含量的配比进行研究,确定最佳配方。结果表明：以30%的原汁含量,8%的白砂糖含量,62%的纯净水为最佳配比。加工出的野生蓝莓果浆型饮料色泽深蓝,具有良好的野生蓝莓香气,果香浓郁,口感醇厚,品质上乘。     

银杏叶与松针复合保健饮料的研制

以银杏叶和松针为原料,通过选取两种提取液的复合比例、糖和酸的加入量3个因素进行单因素试验,并根据单因素试验进行3因素3水平的正交试验,以此确定银杏叶与松针复合饮料配方的最佳工艺,即银杏叶提取液与松针提取液的复合比为1:1.5,与0.07%的柠檬酸、8%的白砂糖、0.05%的抗坏血酸、0.01%的氯化钠、0.001%的乙基麦芽酚、0.2%的羧甲基纤维素钠混合调配,再经过滤、灌装、杀菌、冷却而制得成品具有良好的色泽、口感、风味,并有一定的稳定性。     

糖醋双孢菇软罐头加工工艺研究

以双孢菇为原料,经切片、护色、硬化、调味、杀菌等工艺,研制出酸甜可口、菌味浓郁的双孢菇软罐头,并对加工过程中罐头汤汁进行了配方优化。试验结果表明:汤汁中白砂糖的最佳添加量为30%,白醋最佳添加量为20%,柠檬酸最佳添加量为0.2%,异抗坏血酸钠最佳添加量为0.03%,罐头的最适杀菌条件为100℃,20min。     

椰子水饮料配方及加工技术研究

为了优化椰子水饮料的生产配方与加工技术,以解决椰子水饮料沉淀、口感和贮藏问题,以新鲜成熟椰子水为原料,采用单因素试验和L9(34)正交试验方法,以感官评分为指标,确定了制备椰子水饮料产品的最佳工艺参数。试验结果表明,制备椰子水饮料产品的最佳配方和工艺条件为:椰子汁与水的比例为2∶1(w∶w),糖度5%,pH值为4.6,杀菌条件为100℃、15 min。文中还将添加了保鲜剂与未加保鲜剂的椰子水饮料进行了对比试验,结果表明,添加柠檬酸0.04%、V C0.02%、异抗坏血酸0.01%作为保鲜剂,可以使椰子水饮料更有效地保持新鲜而又有原椰子水的风味和品质。     

沙棘番茄酸奶的研制

以沙棘汁、番茄汁、酸奶为主要原料,配以白砂糖、稳定剂等辅料,运用合理的加工工艺,通过正交试验和感官评定的方法,研制出了一种风味独特、多种营养素兼容的具有保健功能的搅拌型酸奶,研究结果表明该产品的最佳配方为:沙棘汁3.5%,番茄汁21%,白砂糖6%,稳定剂(CMC)0.4%.     

蓝莓果茶的研制

以蓝莓果为主要原料,生产蓝莓果茶;通过预实验确定影响蓝莓果茶的质量的主要因素有：蓝莓果汁添加量、果胶添加量、白砂糖添加量、果糖添加量及柠檬酸添加量。以感官评价为指标,采用单因素试验及正交试验,确定了蓝莓果茶最佳配方为：蓝莓果汁35%、蔗糖25%、果糖5%、柠檬酸0.15%、果胶0.25%、纯净水34.6%。     

毛竹春笋低糖笋脯的加工研究

以毛竹春笋为原料,对影响春笋笋脯品质的原料、切片厚度、护色液配方、淀粉糖浆溶液质量比等关键工艺进行研究。结果表明:采收时间不超过24 h毛竹春笋,选取笋头可食部位,去掉笋尖10～15 cm的过嫩部分,可获得最佳原材料;采用0.6～0.7 cm厚度的笋片能获得笋脯最佳的组织形态、色泽和口感;最佳护色液配方为0.2%CaCl2、1%NaCl、0.05%VitC、0.02%柠檬酸;最佳淀粉糖浆溶液质量比为30%。在上述最佳工艺条件下,制成的毛竹春笋低糖笋脯风味好,色泽自然。     

三倍体毛白杨试管快速育苗技术研究

三倍体毛白杨试管快速繁殖的最佳培养基是 :1/ 2B5 +IBA0 .2mg/L +白砂糖 0 . 15 % +琼脂0 .36 % ,每月的增殖倍数为 3.70 ,生根株率为 97.5 % ,单株生根 2 .7条 ;移栽成活率为 86 .8%。移栽后 6个月的苗高达 4 .35m。     

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.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

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.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

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。     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.