大豆蛋白作水溶性防腐剂中铜的螯合剂的初步研究

大豆蛋白首次被引进于木材防腐处理作为铜的螯合剂。试验结果表明，经过硫酸铜、氨水和大豆蛋白ＨＭ９０处理西黄松（Ｐｉｎｕｓ ｐｏｎｄｅｒｏｓａ）边材，铜的流失有明显减少。在铜氨溶液中加入８和１６ｋｇ／ｍ＾３大豆蛋白ＨＭ９０，其处理木块经流失试验后的固着率平均分别为超始固着率的７５％和６６％，由于蛋白对铜的螯合作用，流失处理后固着率平均增加４０％，最高可达６２％。采用较低浓度的硫酸铜（１６ｋｇ／ｍ＾３）     

高得率浆废水生物净化处理系统研究(Ⅱ)——山杨CTMP、APMP废水活性污泥法处理

研究山杨高得率浆（ＣＴＭＰ、ＡＰＭＰ）废水在实验室用活性污泥法连续处理的净化效果。结果表明：（１）两种废水用活性污泥法处理可得到良好的净化效果。ＣＴＭＰ废水在全部水力停留时间（ＨＲＴ＝１０～５６ｈ）内,ＣＯＤ负荷量在２１８～１２９ｋｇ／ｍ３·ｄ时,ＣＯＤｃｒ、ＢＯＤ５去除率分别为６５９％～８１０％（平均７４６％）和９５５％～９８１％（平均９６８％）;ＡＰＭＰ废水在ＨＲＴ为１０～４６ｈ,ＣＯＤ负荷量为３４７～１６１２ｋｇ／ｍ３·ｄ时,ＣＯＤｃｒ、ＢＯＤ５去除率分别为８４０％～８５６％（平均８４９％）和９８０％～９８９０％（平均９８６％）;（２）在试验采用的全部水力停留时间内,通过处理产生的污泥的ＳＶＩ（污泥指数）均低于１５０ｍＬ／ｇ,污泥的沉降性能良好,在整个试验中,未发现污泥膨胀现象;（３）活性污泥法操作管理简单、方便,对废水的适应性强     

小叶桉中纤板不添加固化剂的生产性试验

海南省农垦三亚木材厂对小叶桉中纤板生产工艺进行改革,采用不添加固化剂生产工艺,经对比试验达到了预期效果,既保证了产品质量,又降低了生产成本。１　生产性试验条件１．１　生产原料 （１）小叶桉（剥皮）,直径１００ｍｍ左右。 （２） ＵＦ胶、固含 ４９％± １％,粘度： １６ｓ（格式管法）,固化时间４７ｓ,使用量１９０ｋｇ（液胶／ｍ３板材）。 （３）防水剂：５８号半精炼石蜡,施加量 ９ｋｇ／ｍ３板材。 （４）氯化铵：配制成 ２０％水溶液, ｐＨ＝ ４． ９,使用量为１％～２％（对干胶）。１．２　生产设备 生产设备为…     

木材防腐的研究进展

从木材防腐性能的研究、防腐剂有效成分的固着率和抗流失性、防腐处理后木材的胶合固化以及力学性能等4个方面重点综述了国内外用环保型防腐剂氨溶烷基胺铜和硼酸盐类化合物处理防腐木材的研究现状,提出今后木材防腐技术开发和研究的方向。     

航空喷洒设备及监测技术的研究 Ⅰ.喷洒设备性能测试

报道新研制的ＨＵ２－ＨＷ１型超低容量喷洒设备与海燕６５０Ｂ飞机配套的技术参数的测试方法和结果。在超音速风洞实验室,用来流风速２７ｍ／ｓ和３３ｍ／ｓ,测试１号雾化头转速依次为７４６０、９３５０ｒ／ｍｉｎ,２号雾化头为８４１０、１１８００ｒ／ｍｉｎ,药液泵压力３．５￣５．０ｋｇ／ｃｍ＾２,流量１５．０￣２１．０Ｌ／ｍｉｎ,有效喷幅４０ｍ,雾滴粒径９５￣１７０μｍ,雾滴密度平均９￣１６滴／ｃｍ＾２,雾滴     

适宜密植苹果新品种──特拉蒙

适宜密植苹果新品种──特拉蒙山东省莱阳农学院引种的３个柱型苹果品种中以特拉蒙品种综合表现最好。在高度密植株行距０．６ｍ×１．０ｍ（１１１１～１３３３株／６６７ｍ２）的情况下，１年生结果株率８０．９％，平均单果重２Ｓ５ｓ。平均株产量１．０６ｋｇ．平均产...     

马桑硬枝扦插育苗试验

马桑硬枝扦插试验结果表明，二年生１６ｃｍ长度的插穗经ＡＢＴ１号生根粉处理后，扦插成活率为６８．３％，秋季苗木封顶后的平均高度为６３．８ｃｍ，新梢基部平均直径０．７４ｃｍ。一年生枝条用清水处理的对照组（８ｃｍ长），扦插成活率为零。     

砷剂白蚁药在土壤中淋溶动态和持效期的研究

经室外１ａ的降水淋溶和室内人工模拟５，７，１０ａ淋溶试验，结果表明，砷铜合剂白蚁药的有效成份砷大部份仍停留在表土层。随着时间的推移，表土层砷量有所下降，下面土层砷量有所上升．生物测试表明，药土对家白蚁毒杀和驱避最低有效浓度为０．０４５７％．木块表层含砷量达６５μｇ／ｃｍ２时，也能有效地防止白蚁取食，据此衡阳市白蚁所改进的新药６倍稀释液土壤处理用量可从目前的３．３ｋｇ／ｍ２减少到２．５ｋｇ／ｍ２，１５ａ后表土层仍可保持上述有效砷量．这样既可节约成本１／４，又可减少环境污染．     

五台山华北落叶松人工林生物生产力与营养元素的积累*

在太行五台山地区，调查华北落叶松人工林林分１６块标准地，并测定了单株平均木各器官生物量及营养元素含量，拟合了华北落叶松林木各器官生物量随年龄变化的ｌｏｇｉｓｔｉｃｓ生长方程。试验表明：华北落叶松立木及林分生物量年平均生长随年龄呈抛物线变化，２４年生时达到高峰，而叶片对干材的净光合同化率１８年生时即达顶峰，约为４００ｇ／ｍ２。１５年生林木各器官主要营养元素总积累量，从大到小顺序为Ｎ、Ｃａ、Ｋ、Ｍｇ、Ｐ，林分每公顷可积累以上五种营养元素的总量是８８８．９１ｋｇ。Ｎ为４０６．８６ｋｇ，其中叶片中Ｎ积累２１４．５６ｋｇ，占总Ｎ积累的５２．７４％；干中Ｎ积累５４．３５ｋｇ，占总Ｎ积累的１３．３６％。１５年生华北落叶松林分，生产１吨干物质即固定Ｎ３．５ｋｇ；而生产１ｍ２木材需固定Ｎ４．６ｋｇ；伐倒１ｍ３木材所消耗的Ｎ仅为０．６１１ｋｇ，占１ｍ３木材需固Ｎ总量的１３．３６％。     

施肥对尾叶桉无性系MLA生长影响的研究

在雷州林业局两个试验点进行了尾叶桉无性系ＭＬＡ施肥试验,林龄３８个月生的结果表明：处理⑥（Ｐ３００ｇ／株＋Ｋ３００ｇ／株＋１５０ｇ／株）的平均蓄积生长量为２９．２４ｍ＾３／ｈｍ＾２．ａ,比处理⑦（常规施肥,滤泥５０００ｇ／株＋Ｐ２５０ｇ／株＋Ｋ１５０ｇ／株）的平均蓄积生长量２６．２６ｍ＾２／ｈｍ＾２．ａ大１１;３％,比ｃｋ（不施肥）的平均蓄积生长量６．３９ｍ＾３／ｈｍ＾２．ａ大３５７．５９％,比总     

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.     

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.     

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.     

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.     

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.     

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。