新防腐剂TWP橡胶木防腐试验

TWP防腐剂对木腐菌的毒性剂量为2.2—3.2kg/m~3,毒杀双钩异翅长蠹初龄幼虫的剂量为1.0kg/m~3,抑制蓝变菌和霉菌的毒性浓度分别为1％及1.5—2.0％,对雄性小鼠口服半致死剂量(LD_(50))为1301mg/kg,使用时对人、畜和环境比较安全,并保持木材原有色泽。生产性应用试验结果表明,橡胶木生材用2.0—2.5％TWP,满细胞法或振荡加压法处理,净药保持量4±0.7kg/m~3,防腐效果相当干硼酚合剂12kg/m~3,并优于进口防腐剂。     

牛肋巴地板木药物处理的试验研究

采用不同药物及不同时间处理牛肋巴地板木开展牛肋巴地板木防蛀、防腐、防变形的试验研究 ,结果表明 :通过不同药物和不同时间处理下防蛀、防腐、防变形特性存在明显差异 ,0 .3%高锰酸钾药液浸泡 9d能显著提高牛肋巴地板木防蛀、防腐、防变形的性能 ,而且牛肋巴地板木的纹理自然清晰美观。分别使用 0 .3%的敌百虫、石灰水和多菌灵药液 ,虽能提高其防蛀、防腐、防变形特性 ,但致使地板木变黑。     

Water absorption of boron-treated and heat-modified wood

Heat treatments change the chemical and physical properties of wood and dimensional stability and hygroscopicity are affected as a result of modifications of wood cell components. This study evaluated the water absorption of wood specimens treated with boron compounds followed by heat treatment. Sugi (Cryptomeria japonica D. Don) sapwood specimens treated with either boric acid (BA) or disodium octoborate tetrahydrate (DOT) solutions were heat-modified at either 180° or 220°C for 2 or 4 h. Carbohydrate composition and water absorption of the specimens were then measured and compared with those of untreated and unheated specimens. Wood carbohydrates were significantly degraded in the specimens after heat treatment. The heat treatment evidently decreased the water absorption and the heat-modified specimens absorbed less water than unheated specimens. The higher the treatment temperature and the longer the treatment time, the lower the amount of absorbed water. The boron-treated and heat-modified specimens, however, showed increased water absorption due to the hygroscopic properties of BA and DOT.     

木粉加入量对木／塑复合材料性能影响的研究

研究了聚丙烯与木粉以不同比率复合而成的材料的物理力学性能和复合形态特征。结果表明：不同混合比率的聚丙烯与木粉进行复合后所得的复合材料，除冲击强度有所降低外，其它力学性能均比纯聚丙烯的有较大幅度的提高。木粉表面的酯化处理可以改善木塑界面之间的相容性和复合材料的均匀性。在木塑复合过程中木塑之间发生镶嵌现象使木塑之间产生物理结合。     

FSY30型林木枝丫切碎机试验分析

FSY30型林木枝丫切碎机是林区林木剩余物碎化处理的专用设备,该机采用圆盘式切碎装置,结构简单实用,解决了我国现有林木剩余物碎化处理设备野外作业性能差、切削效率低和原料适应面窄等问题,为我国林区人工林迹地整理更新、抚育和采伐等作业产生的各种林木剩余物碎化处理提供了适用的设备。该机性能和生产试验结果表明：其作业效率比现有机型提高20%以上,作业成本减少15%以上,具有显著的经济效益和一定的生态效益。     

Effects of early cleaning on young Picea abies stands

Young Norway spruce stands (Picea abies [L.] Karst) are typically cleaned of non-crop species on one or several occasions during young stand stage. In order to objectively evaluate the perceived benefits of early cleaning (EC), we studied the effects of EC on three study sites 2–2.5 years after receiving the treatment. Experiments were established as a randomised complete block design with a total of 40 blocks. Although height growth and mortality were not significantly affected, we found that EC substantially reduced canopy competition and, consequently, the mean diameter of released spruce grew 21–32% faster depending on the site. Furthermore, non-crop trees that were cleared during EC had fewer sprouts in two of the three sites and the sprouts were substantially smaller than the corresponding non-crop trees on control in all sites. EC can reduce the cost of pre-commercial thinning because EC reduced the estimated time needed for subsequent management by 18–49%. Thus, EC offers forest owners and managers an economically viable young stand management option.     

Effect of steam explosion on enzymatic hydrolysis and baking quality of wheat bran

In this study, the effect of steam explosion (SE) treatment on microstructure, enzymatic hydrolysis and baking quality of wheat bran was investigated. Coarse and fine bran were treated at different steam temperatures (120–160 °C) and residence times (5 or 10 min) and then hydrolysed with carbohydrase enzymes. The SE treatment increased water extractable arabinoxylan (WEAX) content from 0.75 to 2.06% and reducing sugars from 0.92 to 2.41% for fine bran. The effect was more pronounced with increased SE temperature and residence time. The highest carbohydrate solubilisation was observed in fine bran at SE treatment of 160 °C, 5 min. WEAX content increased to 3.13% when this bran was incubated without enzyme, while WEAX content increased to 9.14% with enzyme addition. Microscopic analysis indicated that cell wall structure of wheat bran was disrupted by severe SE conditions. Supplementation of SE treated (150 °C, 10 min) bran at 20% replacement level decreased the baking quality of bread. However SE followed by enzymatic hydrolysis increased specific volume and decreased crumb hardness (on the day of baking and after three days of storage). Phytic acid content of bread supplemented with SE treated bran was lower than the one supplemented with untreated bran.     

西藏青稞品种喜马拉雅8号低温处理的SSH-cDNA文库构建及分析

为进一步研究青稞低温抗性相关基因,以喜马拉雅8号为材料,通过抑制差减杂交(suppression subtractive hybridization,SSH)的方法,构建青稞低温环境下的cDNA文库,并通过nr及KEGG数据库对筛选得到的高质量EST序列进行功能注释。结果发现,对随机挑选的281个阳性克隆进行测序,获得209条高质量ESTs序列,其中有117条序列能够在GenBank库中比对到同源性较高的基因或蛋白。对上述117条序列进行GO功能注释及KEGG代谢路径分析,发现其涉及到植物的基础物质、能量代谢、光合作用、信号转导等方面,说明这些基因可能参与了青稞对低温的抗性反应。     

磁化处理的全尾砂料浆沉降参数优化模型

为了提高全尾砂料浆的脱水浓缩效果,将磁化处理技术引入到全尾砂料浆脱水浓缩中,并建立GA-SVM模型优选全尾砂料浆的沉降参数。建立支持向量机（SVM）沉降参数优化模型,以磁感应强度、磁化处理时间、料浆流速、料浆浓度、絮凝剂单耗为输入因子,沉降速度为综合输出因子,通过正交试验建立样本数据对SVM模型进行训练与检验,采用遗传算法（GA）对SVM模型参数进行优化,进而得到磁化全尾砂料浆沉降参数的GA-SVM优化模型。将GA-SVM模型运用到某铁矿磁化全尾砂料浆沉降参数优化中,得到的最佳沉降参数为磁感应强度0.192 T、磁化处理时间1.85 min、料浆速度1.92 m/s、PAC单耗28 g/t,沉降速度可达约155 cm/h。研究表明：适宜的磁化处理条件可提高全尾砂料浆的脱水浓缩效果,节约30.0%~42.5% PAC用量,GA-SVM模型对全尾砂料浆沉降参数预测结果相对误差在5%以内、预测精度高,为全尾砂料浆脱水浓缩及其参数优选提供了一种新思路。