In order to improve the leaching resistance of active ingredient-copper in ammoniacal copper quat-type D （ACQ-D） treated Chinese fir （Cunninghamia lanceolata Hook.）, microwave post-treatments were carried out. The...In order to improve the leaching resistance of active ingredient-copper in ammoniacal copper quat-type D （ACQ-D） treated Chinese fir （Cunninghamia lanceolata Hook.）, microwave post-treatments were carried out. The percentages of leached copper from ACQ-D treated Chinese fir with different microwave post-treatments were obtained after leaching tests by analyzing the copper retention in treated wood. The fixation mechanism of copper in the treated wood was determined with the help of SEM and FTIR spectra, while the valence conversion of copper after microwave post-treatments was studied by UV spectroscopy. Our experimental results show that the percentage of leached copper was reduced significantly after microwave post-treatment over time. This development was reinforced by allowing even more time for the treatment as well as with an increase in the power of microwave post-treatment. The leaching resistance of copper in wrapped samples was better than that in unwrapped samples, which is attributed to the combined effects of temperature and moisture content. Compared with air-dried samples, the valence conversion in the samples with microwave post-treatments changed slightly, which demonstrates that microwave post-treatments cannot impair the natural decay resistance of ACQ-D treated wood. SEM and FTIR spectra showed the presence of crystal particles formed by chemical reactions between copper and wood ingredients in wood cell walls and wood pits. Only a small amount of copper reacted with cellulose, while lignin and hemicellulose were the major bonding sites for copper in wood. Given the experimental results of mechanical properties, microwave post-treatments had a slight effect on the compression strength parallel to the grain and on the erystallinity of ACQ-D treated Chinese fir.展开更多
The rDNA internal transcribed spacer 1(ITS-1) regions of two Chinese fir provanences was amplified and cloned by PCR reaction.The PCR reaction was following:97℃ 5 minutes→95℃ 5 minhtes→Adding the Tag polymerase→9...The rDNA internal transcribed spacer 1(ITS-1) regions of two Chinese fir provanences was amplified and cloned by PCR reaction.The PCR reaction was following:97℃ 5 minutes→95℃ 5 minhtes→Adding the Tag polymerase→94℃ l?min 56℃ 1?min,72℃ 2?min;thirty\|six cycles→72 ℃ 10?min.High quality DNA template is necessary for the amplification of ITS-1 sequence,during the PCR reaction,ten minutes denaturation time and 56℃ annealing temperature are beneficial to amplification.The ITS-1 fragment was ligated to PUC19 plasmid,digested with Hind Ⅱ and transformed into competence cells of E.coli JM83 strain,the cloned strains harboring recombinant plasmid were obtained,those recombinant plasmids were used to sequence for ITS-1 fragment.Sequence analysis indicated that the sequence length is 273 bp,the using percentage of A\,T\,C\,G within ITS1 sequence of Chinese fir were 27.5%\,23%\,21.6%\,27.9% respectively and the G/C content of ITS1 sequence was 48.35%.Comparing with other plants,the G/C content of Chinese fir was less than other plants,whose ITS1 regions have been sequenced.As to ITSI sequence,there was no difference among two Chinese fir provenances,sequence analysis disclosed there were two repeat sequences [AAAG] n and [TTG] nappeared within ITS1 sequence of Chinese fir.展开更多
基金the FANEDD of China (No. 200352)the Fok Ying Tong Education Foundation (No. 101028) for financial support
文摘In order to improve the leaching resistance of active ingredient-copper in ammoniacal copper quat-type D （ACQ-D） treated Chinese fir （Cunninghamia lanceolata Hook.）, microwave post-treatments were carried out. The percentages of leached copper from ACQ-D treated Chinese fir with different microwave post-treatments were obtained after leaching tests by analyzing the copper retention in treated wood. The fixation mechanism of copper in the treated wood was determined with the help of SEM and FTIR spectra, while the valence conversion of copper after microwave post-treatments was studied by UV spectroscopy. Our experimental results show that the percentage of leached copper was reduced significantly after microwave post-treatment over time. This development was reinforced by allowing even more time for the treatment as well as with an increase in the power of microwave post-treatment. The leaching resistance of copper in wrapped samples was better than that in unwrapped samples, which is attributed to the combined effects of temperature and moisture content. Compared with air-dried samples, the valence conversion in the samples with microwave post-treatments changed slightly, which demonstrates that microwave post-treatments cannot impair the natural decay resistance of ACQ-D treated wood. SEM and FTIR spectra showed the presence of crystal particles formed by chemical reactions between copper and wood ingredients in wood cell walls and wood pits. Only a small amount of copper reacted with cellulose, while lignin and hemicellulose were the major bonding sites for copper in wood. Given the experimental results of mechanical properties, microwave post-treatments had a slight effect on the compression strength parallel to the grain and on the erystallinity of ACQ-D treated Chinese fir.
文摘The rDNA internal transcribed spacer 1(ITS-1) regions of two Chinese fir provanences was amplified and cloned by PCR reaction.The PCR reaction was following:97℃ 5 minutes→95℃ 5 minhtes→Adding the Tag polymerase→94℃ l?min 56℃ 1?min,72℃ 2?min;thirty\|six cycles→72 ℃ 10?min.High quality DNA template is necessary for the amplification of ITS-1 sequence,during the PCR reaction,ten minutes denaturation time and 56℃ annealing temperature are beneficial to amplification.The ITS-1 fragment was ligated to PUC19 plasmid,digested with Hind Ⅱ and transformed into competence cells of E.coli JM83 strain,the cloned strains harboring recombinant plasmid were obtained,those recombinant plasmids were used to sequence for ITS-1 fragment.Sequence analysis indicated that the sequence length is 273 bp,the using percentage of A\,T\,C\,G within ITS1 sequence of Chinese fir were 27.5%\,23%\,21.6%\,27.9% respectively and the G/C content of ITS1 sequence was 48.35%.Comparing with other plants,the G/C content of Chinese fir was less than other plants,whose ITS1 regions have been sequenced.As to ITSI sequence,there was no difference among two Chinese fir provenances,sequence analysis disclosed there were two repeat sequences [AAAG] n and [TTG] nappeared within ITS1 sequence of Chinese fir.
