微胶囊技术在缓释香味刨花板制备中的应用

制备薰衣草、茉莉花及迷迭香精油香精微胶囊,采用SEM观察表面形貌并测定香精微胶囊的包埋率及100℃焙烘留香期,发现选用薰衣草精油制备的微胶囊呈现流动性均匀粉状,具有良好的形貌特征,有更高的包埋率和更长的留香期,较茉莉花及迷迭香更适合制备芳香型刨花板。确定薰衣草微胶囊刨花板制造优化工艺参数为:施香量4.5%、施胶量15%、热压温度170℃、热压时间11min,制备出具有缓释芳香气味刨花板,其物理力学性能满足GB/T4897.3—2003规定要求。     

低密度聚乙烯膜胶合板制备工艺研究

以杨木单板为基材,低密度聚乙烯(LDPE)薄膜为胶黏剂制备木塑复合胶合板,探讨了单位面积上LDPE的质量、改性剂种类及热压工艺对木塑复合胶合板胶合强度的影响。结果表明:经过表面改性的杨木单板制备的胶合板胶合强度优于未改性单板制备的胶合板胶合强度;以KH-550为杨木单板表面改性剂(用量2%),采用121 g/m~2 LDPE薄膜,在温度160℃、时间8 min、压力2.0～2.2 MPa热压工艺条件下,制备的木塑复合胶合板胶合强度符合GB/T 9846—2015中Ⅱ类胶合板要求;表面改性单板表面接触角的检测结果表明,经硅烷偶联剂KH-550处理的木材表面接触角最小,其渗透性较好。     

影响阻燃胶合板胶合强度因素的研究

分析了使用BL-环保阻燃剂压制环保阻燃胶合板过程中,热压温度、热压时间、单板浸渍时间和涂胶量对胶合强度的影响,并检测了氧指数、甲醛释放量和含水率。研究表明,使用BL-环保阻燃剂生产环保阻燃胶合板可以达到胶合强度标准,并提出了最佳工艺条件。     

丙烯酸树脂豆基胶黏剂的研究

以丙烯酸树脂作为交联剂,制备共混改性豆基胶黏剂。探讨了助剂加入量、助剂种类、胶液pH值及热压温度对胶合板的胶合强度与耐水性的影响。结果表明:当助剂加入量为胶液的3/1 000、助剂为聚氯化铝、胶液pH值为3.75时,压板工艺为热压时间6 min、热压压力1.1 MPa、热压温度125℃时,胶合板胶合强度为0.74 MPa,符合GB/T9846—2015中Ⅱ类胶合板强度要求。     

豆胶染色杨木胶合板的工艺及性能

研究了豆胶染色杨木胶合板的工艺,并且对其胶合强度和x射线衍射图谱进行分析.实验结果表明:较佳的热压工艺条件为:热压温度160℃,热压压力1.5 MPa,热压时间80 s/mm;用此工艺压制胶合板的胶合强度达到1.50 MPa,表面颜色较好;X射线衍射结果证明了热压后豆胶染色杨木单板的相对结晶度有所提高,达到76.27%.     

等离子体改性热塑性树脂薄膜制备环保胶合板试验

为获得无甲醛释放的环保胶合板,将热塑性树脂薄膜(低密度聚乙烯(LLDPE)、聚丙烯(PP)、聚氯乙烯(PVC))用作胶黏剂,并利用空气介质阻挡等离子体对热塑性树脂薄膜进行表面改性处理以提高薄膜与杨木单板的界面相容性,从而获得性能良好的环保胶合板。研究了等离子体处理对胶合板胶合性能的影响,并从等离子体处理对热塑性树脂薄膜表面化学组分及其对胶合板界面形貌的影响分析其胶合机理。结果表明:在等离子体处理功率为4.5 kW、处理时间为8 m/min的条件下处理热塑性树脂薄膜,胶合板的胶合强度得到显著提高,LLDPE/杨木胶合板的胶合强度从0.49 MPa增至0.81 MPa,PP/杨木胶合板的胶合强度从0.65 MPa提高到0.84 MPa,均达到Ⅱ类胶合板标准要求。其中用等离子体处理后PVC与杨木制备的胶合板能满足Ⅰ类胶合板的标准要求,胶合强度达到0.79 MPa。XPS分析表明,等离子体改性热塑性树脂薄膜的表面发生了氧化反应,引入了含氧官能团,提高了薄膜表面极性,有利于提高薄膜与杨木单板之间的相互作用,从而使得胶合板的界面胶合更为紧密,说明等离子体处理后树脂与杨木单板的相容性提高,树脂能在单板表面更好地附着。热塑性树脂薄膜与杨木单板制备的胶合板仅有极微量甲醛释放,其主要源于木材自身,远低于国家标准对人造板甲醛释放限量的要求。研究证明等离子体处理能明显改善热塑性树脂薄膜与杨木单板的界面相容性。     

漆酶活化木素磺酸盐条件对胶合板强度的影响

采用漆酶活化木素或其磺酸盐制备胶黏剂用于人造板生产,可以消除游离甲醛的污染问题。以漆酶、工业木素及其磺酸盐、杨木为原料,在处理时间分别为30、45、60min,pH值分别为3．5、4．5、5．5,温度20℃条件下,分别以漆酶处理工业木素、木素磺酸钠和木素磺酸铵三种底物制备胶黏剂,然后在热压时间30min,压力4．5～5MPa,热压温度150℃条件下生产杨木胶合板。结果表明,除漆酶木素磺酸钠胶合体系外,漆酶木素和漆酶木素磺酸铵的胶合体系的胶合板胶合强度均达到并超过国家Ⅲ类胶合板的要求。     

4A分子筛改性阻燃胶合板的研制

用4A分子筛改性脲醛树脂、BL阻燃剂处理杨木单板,通过正交试验设计,制备阻燃胶合板并检测其胶合强度及阻燃性能。结果表明,分子筛可提高阻燃胶合板的胶合强度,分子筛加入胶黏剂中对阻燃胶合板的阻燃性能影响不大。分子筛改性阻燃胶合板制造的优化工艺为阻燃剂浓度10%、分子筛量4%、涂胶量380g/m2、热压温度120℃。     

碱木素-大豆蛋白胶黏剂在胶合板中的应用研究

探讨了一种新型木素基无醛胶黏剂在三层杨木胶合板中的应用。为了探究经活化还原处理后的碱木素与大豆蛋白共混制备生物质胶黏剂的工艺,以胶合板的胶合强度为性能指标.采用单因素实验,对漆酶加入量、碱木素,大豆蛋白共混比例、热压温度和热压时间等因素对其影响进行了研究。结果表明.最优工艺参数为:漆酶加入量为木质素的3/5,碱木素一大豆蛋白共混比例1:1,热压温度130℃,热压时间10 min,且此碱木素一大豆蛋白胶合体系的胶合强度达到并超过国家Ⅱ类胶合板的要求。     

小球藻蛋白基胶黏剂的制备及其胶合性能研究

小球藻蛋白具有可再生、价格低廉等优点,可用于制备蛋白基胶黏剂。采用氢氧化钠(Na OH)、十二烷基硫酸钠(SDS)和三羟甲基丙烷三缩水甘油醚(TTE)改性处理小球藻蛋白后制备胶黏剂。多种方式表征结果显示,改性处理破坏了小球藻蛋白的球形结构,提供了更多的交联位点,从而提高了胶黏剂的胶合强度及耐水性能。在优化工艺参数:双面涂胶量400g/m2,热压压力1.5 MPa、热压温度150℃、热压时间8 min的条件下,制备的三层桉木胶合板的干、湿胶合强度分别为1.78、1.11 MPa,满足GB/T 9846—2015《普通胶合板》中II类胶合板的要求。     

薰衣草实生苗不同生长条件的最优组合探究

为丰富内蒙古地区观赏花卉品种,从云南引进三种不同的薰衣草进行了适应性栽培试验。试验设计以正交实验为依据,设置4个因素、3个水平,在为期1年的实践中,得到了初步的结论,找到了在设置因素条件下的最优组合,即覆膜不施肥条件下,3 d为一个灌水周期,细叶薰衣草生长情况达到最佳。可为后续的研究提供参考。     

薰衣草景观应用与设计初探

通过对国内薰衣草景观的调研,结合相关文献资料研究,指出薰衣草应用现状中存在的问题和不足,并对薰衣草景观的应用方向、具体应用方式和设计要求进行初步探讨,以期加快对薰衣草的推广与应用。       

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.