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31.
J. R. Clearwater S. P. Foster S. J. Muggleston J. S. Dugdale E. Priesner 《Journal of chemical ecology》1991,17(2):413-429
The specific status ofCtenopseustis obliquana pheromone-types I, II, and III has been more fully examined. Females of types I and III produce a mixture of (Z)-8- and (Z)-5-tetradecenyl acetates (Z8-14:Ac, Z5-14: Ac). The previously reported different ratios of these two components in females of the two types (type I=8020, III=9010) have been reinvestigated. The median ratios of each type differed significantly, although there was some overlap in the ranges of these ratios. A field cage trial showed that males of type III are attracted to females of type I, so the observed differences may be ascribed to intraspecific variation. In contrast to females of types I or III, females of type II produce Z5-14Ac but no Z8-14Ac. The electroantennogram (EAG) profile of antennae of type II males shows a maximum response to Z5-14Ac, while the EAG profiles of types I and III show a strong response to Z8-14Ac. In wind tunnel tests using mixtures of these two compounds, type II males prefer blends consisting of all or mostly Z5-14: Ac, while type I males showed a preference to a mix of 70% Z8-14Ac plus 30% Z5-14Ac. We found that type I males are attracted to type I females when offered a choice between type I and type II females in a field cage test and that type II males similarly prefer type II females. Males of types I and II have specialist cells for Z8-14Ac and Z5-14Ac but differ with respect to relative densities of these cells and to further cell types responsive to other alkenyl acetates. Type IIC. obliquana is considered therefore a sibling species of types I and III. In addition, the amount of Z5-14Ac produced by type II females varied geographically. Females from the North Island produced significantly less (median=1.2 ng) Z5-14Ac than females from the South Island (median=2.2 ng). Type II populations in the North Island morphologically resembled sympatric type I, rather than type II from the South Island and are designated as type II (North Island). Type II (North Island) populations have so far been found only at Rukuhia (near Hamilton) and from Kerikeri. In contrast, type II populations are sympatric with type III populations over much of the South Island. In a field cage trial, males of types II and II (North Island) were attracted to females of both II and II (North Island). We tentatively ascribe the differences between type II and type II (North Island) to intraspecific variation. 相似文献
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介绍了由氧化铅与冰醋酸在一定温度下反应生成碱式醋酸铅,碱式醋酸铅在一定条件下与二氧化碳反应生成碱式碳酸铅,再经沉淀、抽滤,制得结晶产品。探讨了溶液pH、反应温度、二氧化碳流量、水中的杂质、总铅质量分数等对碱式碳酸铅结晶的影响,得出了制备碱式碳酸铅的最佳工艺条件:pH=6.5时停止通入二氧化碳,反应温度25~30℃,二氧化碳流量控制在0.5~3L/min,把河水或自来水经过离子交换处理,溶液中总铅质量分数控制在2%~5%。 相似文献
36.
乙酸酐对魔芋葡甘聚糖的改性 总被引:3,自引:0,他引:3
研究了乙酸酐对魔芋葡甘聚糖的改性,制备了魔芋葡甘聚糖醋酸酯,优化了制备工艺条件,得出了酸性催化剂条件下,乙酰化魔芋葡甘聚糖的最佳改性工艺条件为:n(乙酸酐)∶n(魔芋葡甘聚糖)=4 8∶1,反应温度50℃,反应时间4h,催化剂c(H2SO4)=0 038mol/L,取代度DS=0 662。物化性能测试表明,取代度超过0 270时,魔芋葡甘聚糖醋酸酯在水中溶解;60℃时最大溶解度为w(魔芋葡甘聚糖醋酸酯)=12%,取代度超过0 469时,魔芋葡甘聚糖醋酸酯能制成均匀的薄膜,膜厚10~30μm。 相似文献
37.
S. A. Katovich P. D. Swedenborg M. Giblin E. W. Underhill 《Journal of chemical ecology》1989,15(2):581-590
The sex pheromone ofCydia toreuta (Grote), the eastern pine seedworm, was investigated using electroantennogram (AG) measurements, gas chromatography (combined GC-FID-EAD) measurements, and field tests. (E,Z)-8,10-dodecadienyl acetate (E,Z8,10-12:Ac) and (E,E)-8,10-dodecadienyl actetate (E,E8,10-12: Ac) produced both the highest EAG and EAD responses. Only a single antennal stimulatory peak was observed when female abdominal tip extracts were analyzed by GC-FID-EAD, which corresponded exactly with that of authenticE,Z8,10-12: Ac. Field tests confirmedE,Z8,10-12: Ac as the major pheromone component. TheE,Z isomer by itself caught equivalent numbers of male moths as did caged females. The addition of theE,E isomer to theE,Z form increased trap catch, although not significantly (P = 0.05). The addition of (Z,Z)-8,10-dodecadienyl acetate to theE,Z isomer significantly (P=0.05) reduced trap catch, while the addition of (Z,E)-8,10-dodecadienyl acetate to theE,Z form also decreased trap catch, but not significantly (P=0.05). 相似文献
38.
HIPS/EVA/CB体系的相容性 总被引:1,自引:0,他引:1
研究了炭黑(CB)对高抗冲聚苯乙烯(HIPS)/乙烯-乙酸乙烯酯共聚物(EVA)共混体系相容性的影响,并预测了共混体系的相形态转变点。填充CB后,当EVA用量大于50 phr时,碳氧双键伸缩振动峰的位置由1 737.9cm~(-1)偏移到1 706.5 cm~(-1)附近,且在1 240.0 cm~(-1)附近的碳氧单键峰减弱,近乎消失。采用半经验公式对共混体系进行理论预测,HIPS/EVA/CB共混体系理论上发生相形态转变时,HIPS的临界质量分数为50%~60%,经傅里叶变换红外光谱和扫描电子显微镜照片分析,共混体系发生相形态转变时,HIPS的质量分数约为42%。 相似文献
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V. Kova
evi S. Lu
i D. Hace A. Glasnovi I. mit M. Bravar 《The Journal of Adhesion》1994,47(1):201-215
The properties of poly(vinyl acetate) compositions prepared as potential wood adhesives were investigated. The paper presents the results of the influence of various kinds of inorganic fillers based on calcium carbonate and alumino-silicate and an organic filler, starch, on the adhesive composition properties. The comparison among rheological behavior of the adhesive dispersions concerning the specific role of fillers were made. Mechanical and relaxation properties of the adhesive films could reveal the effect of filler characteristics on the polymer matrix. The significant influences of particle size distribution and specific surface area on the poly(vinyl acetate) adhesive composition were determined, along with other filler characteristics. 相似文献