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141.
We tested how terpenoid (i.e., monoterpenes and resin acids) composition and concentration in wood affects resistance against wood-borers and decaying fungi. Scots pine (Pinus sylvestris) wood from nine provenances having variable terpenoid profiles was studied against the old house borer, Hylotrupes bajulus, and the decay fungus, Coniophora puteana. Provenances represented a 1200-km N-S transect from Estonia to northern Finland, but they were all cultivated for 7 years in the same nursery field, in central Finland. Mean relative growth rate (MRGR) of small H. hajulus larvae positively correlated with the total monoterpene concentration of wood, and feeding was associated with high proportion of levopimaric+palustric acid in wood. Provenance did not affect the MRGR of small or big larvae, but big larvae consumed more wood and produced more frass on the northern Ylitornio trees than on the southern Rakvere and Ruokolahti trees. Low beta-pinene and total monoterpene concentration and low beta: alpha-pinene ratio in wood were all associated with a high number of eggs. The most northern Muonio provenance was the most favored as an oviposition site, differing significantly from Saaremaa, Tenhola, and Suomussalmi. Wood from Saaremaa, Tenhola, Ruokolahti, and Suomussalmi provenance was most resistant against decay fungus, differing significantly from that of Kinnula provenance. However, decay resistance was not clearly associated with the concentrations of wood terpenoids. These results suggest that monoterpene composition of wood affects resistance against wood-boring Cerambycid beetles, but resistance against wood-decaying fungi is not as clearly associated with wood terpenoids.  相似文献   
142.
改性脲醛树脂胶粘剂的研究   总被引:8,自引:1,他引:8  
主要利用混合改性剂,改进生产工艺以及施胶时加入填料等方法研究脲醛树脂胶粘剂的游离甲醛含量,剪切强度、耐水性等问题,得到低毒,综合性能良好的胶粘剂。  相似文献   
143.
We determined variation in both the concentration and composition of terpenoids in needles and wood within nine Scots pine (Pinus sylvestris) provenances. Seedlings of different provenances representing a 1200-km N–S transect from Estonia to northern Finland were cultivated in Suonenjoki nursery field, central Finland, for seven years. Growth of seedlings and the number of vertical resin ducts in wood were also determined. -Pinene and 3-carene were the major monoterpenes both in the needles and wood. The total monoterpene concentration was about five times higher in the needles than in the wood. A strong positive correlation was found between proportional quantities of several terpenes of the needles and wood, particularly for 3-carene, sabinene, and terpinolene. The needles contained both labdane-type and tricyclic resin acids, whereas the wood contained only tricyclic ones. The wood had a four times higher tricyclic resin acid concentration than the needles. The highest total monoterpene concentration in the needles and in the wood occurred in the most northern Muonio provenance and in the most southern Saaremaa provenance plants, respectively. The amount of high 3-carene genotype trees decreased among the northern provenances. The wood of the most northern Muonio provenance showed the lowest total resin acid concentration, but provenance did not affect total tricyclic resin acids in the needles. Korpilahti provenance trees from central Finland had the best growth in height. In addition, Korpilahti and Ruokolahti provenance trees showed largest radial growth of stem and smallest number of vertical resin ducts. The results suggest that especially the proportional quantity of 3-carene in the needles could be used in estimating the amount of this compound in the wood and vice versa.  相似文献   
144.
离子交换树脂非均相催化乙酰化合成乙酰甲胺磷   总被引:3,自引:0,他引:3  
刘平乐  李国兵  焦飞鹏  王良芥  罗和安 《农药》2003,42(3):19-20,23
研究了在间易搅拌釜中以阳离子交换树脂为催化剂,由甲胺磷催化乙酰化合成乙酰甲胺磷。分别考察了不同类型离子交换树脂的催化乙酰化作用。并且研究了搅拌速度,催化剂用量以及反应温度对乙酰化反应的影响。研究结果表明,以NKC9型离子交换树脂在333.15K温度下具有最好的催化乙酰化作用。  相似文献   
145.
张军  钟山  丁家海 《弹性体》2002,12(6):5-9
在选择三元共聚尼龙(PA)、聚氯乙烯(PVC)、丁腈橡胶(NBR)为主体材料,制备PA/PVC/NBR(10/30/60)三元共混弹性体的工作基础上,进一步探讨了填料品种和用量,共混温度,加料顺序等因素PA/PVC/NBR三元共混弹性体的影响。试验结果表明:在PA/PVC/NBR(10/30/60)共混体系中,补强型填料的补强效果优于非补强型的填料,6种填料补强效果依次是:快压出炭黑>半补强炭黑>白炭黑>活性重质,CaCO3>陶土>滑石粉,快压出炭黑的适宜用量是20-50份。在制备PA/PVC/NBR三元共混物时,适宜的共混温度是122-140℃,并且采用二段法混工艺制得的共混物性能优于采用一段法共混工艺。  相似文献   
146.
三聚氰胺改性脲醛树脂粉体胶粘剂的研制   总被引:3,自引:0,他引:3  
用三聚氰胺改性脲醛树脂改善了胶粘剂的耐沸水性,并有效地降低了游离甲醛含量。三聚氰胺改性脲醛树脂粉体胶粘剂应用更广泛,性能更可靠。  相似文献   
147.
丙烯酰胺改性蜜胺甲醛树脂的絮凝性能研究   总被引:3,自引:1,他引:3  
合成了丙烯酰胺改性三聚氰胺(蜜胺)甲醛树脂,研究了其絮凝性能,利用烧杯澄清试验法,考察了酸碱条件,絮凝剂投加量和静置时间对絮凝性能的影响。实验证明:酸性条件,絮凝剂投加量为50mg/L,静置时间为20min时改性树脂的絮凝效果最好。并且与不同絮凝剂进行了浊度去除效果比较。  相似文献   
148.
用氧指数 (LOI) ,TG法测定研究了 2 ,4,6-三溴苯胺 (TBA)对环氧树脂酸酐固化物阻燃耐热性的影响 ,结果表明 TBA能较好地阻燃树脂固化物 ,TBA与 Sb2 O3 和磷酸三苯酯 (TPP)配用时具有阻燃协同效应 ,且对环氧树脂酸酐固化物的热稳定性影响较小。  相似文献   
149.
Zhiguang Xu 《Polymer》2007,48(20):6134-6144
Poly(?-caprolactone)-block-polydimethylsiloxane-block-poly(?-caprolactone) triblock copolymer (PCL-b-PDMS-b-PCL) was synthesized via the ring-opening polymerization of ?-caprolactone with dihydroxypropyl-terminated PDMS (HTPDMS) as the initiator. The triblock block copolymer was characterized by means of Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR) and gel permeation chromatography (GPC). The triblock copolymer was incorporated to prepare nanostructured thermosetting blends. The morphology of the epoxy thermosets containing PCL-b-PDMS-b-PCL were investigated by means of atomic force microscopy (AFM), transmission electronic microscopy (TEM) and small-angle X-ray scattering (SAXS). The thermomechanical properties of the nanostructured blends were investigated by means of differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The formation of the nanostructures in the thermosetting composites was judged to follow the self-assembly mechanism in terms of the difference in miscibility of PDMS and PCL subchains with epoxy resin after and before curing reaction.  相似文献   
150.
制备工艺参数对抗菌胶衣树脂抗菌性能的影响   总被引:1,自引:0,他引:1  
本文以硅溶胶为载体,通过负载金属银离子、TiO2、ZnO以及A l2(S iO3)3于硅溶胶中,制备了复合无机抗菌剂,并将其加入到胶衣树脂中制备了抗菌胶衣树脂。主要研究了抗菌剂的制备参数、含量及种类和抗菌胶衣树脂的制备参数对胶衣树脂抗菌性能的影响。实验结果表明,随着烧结温度的升高,抗菌胶衣树脂的抗菌率呈现先升高后降低的趋势,烧结温度为1000℃时抗菌胶衣树脂的抗菌率最高;随着球磨时间的延长,抗菌胶衣树脂的抗菌率呈上升趋势,球磨时间大于6h时抗菌率增加的幅度减小;随着苯乙烯含量的增加,其抗菌率也逐渐增加,苯乙烯含量为10m l时抗菌率达94%;随搅拌时间的延长,抗菌胶衣树脂的抗菌率也有所增加,搅拌时间为1h时抗菌率为94%。  相似文献   
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