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61.
Fengqiang Wang Zhijun Zhang Qingwen Wang Jiayin Tang 《Frontiers of Forestry in China》2008,3(4):487-492
An intumescent waterborne amino-resin fire-retardant coating for wood (C) was synthesized and its fire-retardant and smoke-suppressant
properties were investigated. The main film-builder of C was urea-formaldehyde resin blended with polyvinyl acetate resin.
The intumescent fire-retardant system of C consisted of guanylurea phosphate (GUP), ammonium polyphosphate (APP), pentaerythritol
(PER) and melamine (MEL). Specimens of plywood painted, respectively, with a commercial intumescent fire-retardant coating
(A), a synthesized coating (C), and the main film-builder of coating C (B), as well as an unpainted plywood (S-JHB), were
analyzed by cone calorimetry (CONE). The results show a marked decrease in the heat release rate (HRR) and the total heat
release (THR), an increased mass of residual char (Mass), a marked postponement in time to ignition (TTI) and a reduced carbon
monoxide production rate (P
CO). The smoke production rate (SPR) and total smoke production (TSP) of the plywood painted with coating C were observed with
the CONE test. The overall fire-retardant and smoke-suppressant performance of the synthesized coating C was much better than
that of the commercial coating A. The thermo-gravimetric analysis (TGA) results of coating C and its film-builder B indicated
that the thermal degradation process of B was slowed down by the addition of the intumescent fire-retardant system; the increase
in the amount of charring of coating C was considerable.
__________
Translated from Scientia Silvae Sinicae, 2007, 43(12): 117–121 [译自: 林业科学] 相似文献
62.
松果梢斑螟成虫的寄主选择 总被引:4,自引:1,他引:3
在松果梢斑螟成虫产卵期,采用顶空吸附法和CC-:MS分析,研究虫害后油松球果萜类挥发物成分的变化.油松虫害球果(枝)单萜挥发物的释放呈现昼夜节律,并且特异性挥发组分为1R-(+)-α-蒎烯、β-香叶烯和D-柠檬烯.梢斑螟成虫为夜出性害虫,因此产卵期晚上的球果(枝)挥发物更有意义.油松和华山松球果的触角电位(EAG)测试表明:虫害球果与健康球果相比,梢斑螟(雌雄蛾)对油松虫害球果的EAG反应更明显;而对华山松虫害球果和健康球果的EAG反应差异不明显.Y-型嗅觉仪的趋向试验表明:雌成虫的寄主选择性明显高于雄虫,油松球果提取液的引诱作用高于华山松球果,而当年生针叶提取液、虫害球果及其提取液挥发物对雌成虫的引诱作用均高于健康球果;挥发物标准品测试显示,1R-(+)-β-蒎烯、β-香叶烯和D-柠檬烯组合具有明显的引诱作用.虫害油松球果及其提取液可显著刺激雌成虫产卵,表明油松虫害球果提取液组分中存在着雌成虫的产卵刺激物;华山松球果提取液的存在明显抑制了雌虫在油松虫害球果提取液滤纸上的产卵,表明华山松球果提取液中可能有产卵拒避剂. 相似文献
63.
Guomo Zhou Yufeng Zhou Shuquan Yu Shangbin Bai Fengzhu Lu 《Frontiers of Forestry in China》2009,4(2):178-184
To determine the suitability of Schima superba Gardn. et Champ as a fuelbreak, we compared and analyzed the flammability characteristics of tree litter from three trees
commonly grown in south China, i.e., Pinus massoniana Lamb., Cunninghamia lanceolata (Lamb.) Hook., and S. superba, using a cone calorimeter at five different water content levels. Water content levels of 10%, 15%, 20%, 25% and 30% for
the litter were manually produced with a new technique of adding water to dry litter. The cone calorimeter utilized a radiant
heat intensity for leaf litter of 20 kW/m2 (510°C) and for twig litter of 30 kW/m2 (608°C). Results show that fixing the water content level by adding water with a pipette was an acceptable technique. For
S. superba, compared to P. massoniana and C. lanceolata, 1) the heat release rate (HRR) was slower and lower; 2) the total heat released (THR) from the material was lower and started
later in the burning process; and 3) except for the 10% water content, pkHRR/TTI was less. These results show that overall,
S. superba was the best of the three species to be used as a fuelbreak in south China.
__________
Translated from Scientia Silvae Sinicae, 2008, 44(5): 96–101 [译自: 林 业科学] 相似文献
64.
少果悬铃木遗传分析初步 总被引:5,自引:0,他引:5
通过对合肥等地选育出的一球悬铃木少果植株和正常结果植株的体细胞染色体组型分析和过氧化物酶同工酶酶谱分析,找出了两者遗传上的差异。 相似文献
65.
66.
67.
JESSICA R. NIESET JOSEPH F. HARMON SUSAN M. LARUE 《Veterinary radiology & ultrasound》2011,52(5):580-588
Urinary bladder cancer is difficult to treat accurately with fractionated radiation therapy (RT) due to daily positional changes of the bladder and surrounding soft‐tissue structures. We quantified the daily motion experienced by the canine bladder with patients in dorsal vs. sternal vs. lateral recumbency. We also described the dose distribution for three different planning target volume expansions (5, 10, and 15 mm) for each of the three positions to ensure adequate bladder dose and minimize irradiation of nearby healthy tissues. Analysis was based on data from retrospective daily cone‐beam computed tomography (CT) (CBCT) images obtained for positioning of canine patients undergoing routine RT. Organs of interest were contoured on each CBCT data set and the images, along with the contours, were registered to the original planning CT. All measurements were made relative to the planning CT and dosimetric data for the organs of interest was determined using a dose volume histogram generated from sample parallel‐opposed beam configuration. There was a wide range in bladder position throughout treatment. The least amount of bladder variation and the lowest rectal dose was with dogs in lateral recumbency. It was also determined that a margin of 10 mm would allow for sufficient dose to be delivered to the bladder while minimizing rectal dose. 相似文献
68.
69.
The key for puparia of the three species of larch-cone-flics (Strobilomyia) is developed based on their external morphological characteristics on anal (posterior) part which includes segmental protrusions
and background texture. Some characteristics which are only visible under scanning microscope are also included even though
they are supplementary in this key. Those three commonly found larch-cone-infestinganthomgiids arestrobilomyia melania, S. infrequens andS. laricicola. 相似文献
70.
对球果损失造成油松良种减产的分析 总被引:4,自引:0,他引:4
调查了油松种子园、母树林良种减产的原因,主要是由于球果在生长发育过程中的大量损失;而虫害、雌花授粉不良、因缺少水肥造成的落花落果是油松球果损失的主要原因。同时提出了减少球果损失的几点技术措施。 相似文献