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依据松香的结构及其氧化机理,考察酚类、亚磷酸酯类、硫酯类等对聚合松香的浅色反应.结果表明:十二硫醇、环氧大豆油、SWC-80可作为聚合松香酯化的浅色剂,以SWC-80为浅色剂、DynOm为催化剂,制得的浅色聚合松香甘油酯,颜色为2号(加纳),酸值12.1 mgKOH·g-1,软化点为135℃;制得的浅色聚合松香季戊四醇酯,颜色为3号(加纳),酸值22.1 mgKOH·g-1,软化点为143℃. 相似文献
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以工厂所用的普通一级松香为主原料,采用多种催化剂,研究了合成浅色145#松香季戊四醇酯的工艺条件.实验选用8种国内外适合松香树脂的催化剂,主要探讨了催化剂种类及复配条件与产品质量之间的关系.并对反应温度、反应时间和原料配比等影响因子进行了探讨.通过实验得到,合成145#松香季戊四醇酯的适宜工艺条件为反应温度(275±2)℃,反应时间6 h(可根据实际需要适当延长),适宜的反应物配比为松香、季戊四醇、催化剂A、催化剂G的质量比为10.120.0020.0005.在上述工艺条件下,得到145#松香季戊四醇酯产品,其质量指标是色泽3(加纳比色),软化点91.7℃,酸值24.8 mg/g. 相似文献
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《林产工业》2014,(5)
<正>项目名称:无色松香及无色松香酯产业化项目申报单位:广西梧州日成林产化工股份有限公司(二等奖)1项目简介由广西梧州日成林产化工股份有限公司完成的无色松香和无色松香酯产业化项目于1998年提出计划,先后被列为1999年国家火炬计划项目和1999年广西科技与经济结合重大项目。项目于2003年9月通过广西区科技厅主持的国内相关专家进行的鉴定,技术水平处于国内领先。2004年3月,该项目主要产品无色松香、浅色松香树脂以及氢化松香被认定为广西区高新技术产品,同时该公司被认定为广西区高新技术企业。2004年4月,项目成果获得梧州市科技进步一等奖。2005年2月,项目成果获得广西科技进步二等奖。2008年5月,项目成果获得梧州市科技进步特别贡献奖。 相似文献
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项目名称:无色松香及无色松香酯产业化项目
申报单位:广西梧州日成林产化工股份有限公司(二等奖)
1 项目简介
由广西梧州日成林产化工股份有限公司完成的无色松香和无色松香酯产业化项目于1998年提出计划,先后被列为1999年国家火炬计划项目和1999年广西科技与经济结合重大项目.项目于2003年9月通过广西区科技厅主持的国内相关专家进行的鉴定,技术水平处于国内领先.2004年3月,该项目主要产品无色松香、浅色松香树脂以及氢化松香被认定为广西区高新技术产品,同时该公司被认定为广西区高新技术企业.2004年4月,项目成果获得梧州市科技进步一等奖.2005年2月,项目成果获得广西科技进步二等奖.2008年5月,项目成果获得梧州市科技进步特别贡献奖. 相似文献
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由中国林科院林产化学工业研究所开发的浅色松香树脂生产线在福建省龙岩地区投产并获得了良好效益。 松香和改性松香树脂,有较广的用途和市场,以往因产品质量低劣,不仅外销无门而且内销也受阻。由中国林科院林产化工研究所高级工程师杨必胜主持设计的浅色松香树脂生产 相似文献
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PS-10对松香的浅色化作用机理初探 总被引：1，自引：0，他引：1
研究了浅色剂PS-10对松香的浅色作用机理。对反应前后松香物理指标及其化学组成分析发现：随着PS-10用量增加、反应温度升高或反应时间延长，松香颜色变浅。加入PS-10反应后松香的枞酸型树脂酸含量由70．6％下降至18．8％，去氢枞酸从7．3％增加至30．6％，二氢树脂酸从0增加至12．2％。结果表明，PS-10对松香歧化反应起了催化剂的作用。同时，PS-10在松香脱色过程中，发挥了抗氧剂的作用，它的抗氧活性表现在酚羟基和硫原子上，酚羟基具有捕捉游离基的功能，而硫醚可以分解氢过氧化物，因而表现出分子内协同作用。 相似文献
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A. Lehtijärvi H. T. Doğmuş‐Lehtijärvi A. G. Aday Kaya S. Ünal S. Woodward 《Forest Pathology》2017,47(6)
Although several Armillaria species have been reported in Turkey, there is little information about their ecology in Turkish forests. In this study, we investigated five forest stands, approximately 5–74 ha in size, in Kastamonu province in the Black Sea Region of Turkey for the presence of Armillaria species in stumps and logs. The stands were mixed Abies nordmanniana ssp. bornmülleriana and Pinus sylvestris forests managed using a selective cuttings system; the proportion of fir in the total number of stems and stumps ranged from 36 to 98%. Based on sequence analysis of the internal transcribed spacer and intergenic spacer regions of the rDNA, all rhizomorphs sampled from the stumps and logs were of Armillaria ostoyae. The size of the genets was estimated with random amplified microsatellites analysis of the isolates and ranged from single stumps to approximately 450 m2. One to seven genets were found in each stand. These results indicate that the genets had arisen from spores and vegetative spread was limited on most sites. 相似文献
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通过对上海松江中央公园内65株特大银杏树白蚁为害情况的调查,发现该公园银杏受害率为100%,其中存在活白蚁的银杏占总量的56.9%,采用毒土处理、粉剂疗法、建立白蚁监测点等措施,经过两次灭杀,活白蚁的灭杀率达到92.3%和93.3%,从而使存在活白蚁银杏树的比例从56.9%下降到2.7%,白蚁发生情况明显降低。
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建平半干旱地区石质山地造林技术研究 总被引：1，自引：0，他引：1
研究了不同植物在石质山地的造林成活率、土壤化学性质随造林年限的变化和造林措施对土壤化学性质和植物胸径、树高年净生长量的影响。结果表明：不同植物在石质山地的成活率在21%～85%之间,其中白榆和沙打旺的成活率分别为81%和85%,而小叶杨、刺槐、栾树的成活率均在70%左右;植被能明显提高石质山地不同土层的有机质、全N、P2O5含量,但提高程度随土层深度、养分种类和造林年限的不同而不同;在同一土层,生物复合肥料、菌剂和保水剂均显著提高土壤有机质含量（p〈0.01）并显著降低土壤P2O5含量（p〈0.01）;只有保水剂可引起土壤全K含量的明显升高;生物复合肥料、菌剂和保水剂均显著提高白榆、小叶杨、刺槐、栾树树高和胸径的年净生长量,但保水剂的提高程度最高。 相似文献
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植物经常暴露在各种生物和非生物的胁迫之下,这些胁迫会影响植物的生长发育和繁殖并最终导致植物死亡。为了抵御不利的环境条件,植物已经进化出复杂而精细的网络来感知胁迫并激活防御系统。为此,植物激活许多信号转导通路,这些信号转导通路可以改变一些胁迫响应基因的表达,从而引起植物形态、生理和生化的改变以适应逆境。DNA胞嘧啶甲基化是高等真核生物的主要表观遗传机制之一,在维持基因组稳定性和调节基因表达方面起着关键作用。表观遗传变异比遗传变异更为灵活。一旦环境条件发生变化,为了适应新的环境植物都会发生表观遗传的改变。许多研究表明DNA甲基化参与植物的发育和应激反应。基于相关研究对DNA甲基化进行了综述,对植物逆境胁迫有重要意义。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(6):530-542
Abstract The success of natural regeneration on patch clear-cuts in Norway spruce stands in Southern Finland was examined in terms of stocking and tree height. The experiment was established in mature spruce stands in the submesic Myrtillus (MT) site type. In each of the eight study sites, three plots were treated with clear-cutting and planting, clear-cutting with partial tree retention and planting, and patch clear-cutting without site preparation, respectively. In three of the study sites, one plot with patch clear-cutting and site preparation was established. Each plot was 1 ha, out of which three patches of 40×40 m were clear-cut in the patch treatments. 10–11 years after cutting, the patches had on average 1316 crop trees ha–1, of which 91% were spruces. Some 27% of the stands were up to the target stocking level (≥1600 ha?1), and 36% were at least satisfactory (≥1300 ha?1). Site preparation did not yield greater stocking levels on patches, but that result is ambiguous due to a difference in initial stocking. The average spruce tree height in the patches (0.76 m) was much smaller than in the case of clear-cutting and planting (2.42 m). In conclusion, the patches had been restocked tolerably well with spruce and birch for practical purposes during the 10- to 11-year period, but the regeneration process had been very slow compared to clear-cutting and planting. 相似文献
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The study focused on the success of regeneration on patch cuts in spruce-dominated stands in terms of stocking and tree height. It was based on an experiment in the Kainuu region in northern Finland. The experimental design included 8 stands with 58 clearcut patches of variable size (0.09–0.37?ha), on which either natural regeneration without site preparation or site preparation and planting of Scots pine was applied. A regeneration survey was conducted 13–15 growing seasons after treatments. Patches without site preparation had been restocked quite well from natural seed sources. The average number of trees was about 11,000?ha?1, of which 1700?ha?1 crop trees. With site preparation and planting, the stocking levels were also very high, 25,000 and 2100?ha?1, respectively. One hundred percent of the planted patches and 75% of the naturally regenerated patches had an acceptable density. Restocking was equally good across the range of patch sizes. Tree growth had been somewhat slower in the smallest patches than in the largest ones in the range. Natural regeneration was capable of yielding good regeneration results in most patches, especially when site preparation was applied. Stocking levels and height development were higher yet in the planted patches. 相似文献
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Keisuke Kojiro Yuzo Furuta Makoto Ohkoshi Yutaka Ishimaru Misao Yokoyama Junji Sugiyama Shuichi Kawai Takumi Mitsutani Hiromasa Ozaki Minoru Sakamoto Mineo Imamura 《Journal of Wood Science》2008,54(6):515-519
To investigate the changes in microstructures of wood with elapsed time in the environment, CO2 adsorption onto dry wood was measured at ice-water temperature (273 K) for samples aged from 0.1 years to over 1000 years.
The micropore size distribution was obtained using the Horvath-Kawazoe method. Micropores smaller than 0.6 nm in wood decreased
in number with elapsed time in the environment, and a negative correlation was found between cumulative pore volume for pores
smaller than 0.6 nm and elapsed time in the environment. Cumulative pore volume in the 1000-year sample was almost half of
that in the 0.1- year sample. Micropores smaller than 0.6 nm in wood with a few decades or more of elapsed time increased
in number after rewetting and drying. Consequently, microstructures of wood with longer time elapsed in the environment were
considered to be more stable, because of longer-term thermal motion and possibly more repeated moisture adsorption and desorption
and/or temperature variation in the environment. 相似文献