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[目的]建立一种测定溴氰菊酯乳油中顺式二溴菊酰氯杂质含量的高效液相色谱分析技术。[方法]采用CHIRALPAK?AD-H不锈钢柱和DAD检测器,以异辛烷∶1,4-二氧六环(体积比90∶10)为流动相,在210 nm波长下对顺式二溴菊酰氯进行分析定量测定。[结果]顺式二溴菊酰氯的线性相关系数R2为0.9996,标准偏差为0.0013,变异系数RSD为2.71%,平均回收率为87.85%。[结论]该方法操作简单,分离效果良好,具有较高的准确度和精密度,线性关系良好,适用于50 g/L溴氰菊酯乳油中顺式二溴菊酰氯杂质的定量分析。 相似文献
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采用氨基丙基三乙氧基硅烷偶联剂处理涤纶蚊帐,然后将处理后的蚊帐浸泡在添加溴氰菊酯悬浮液的聚氨酯胶粘剂乳液中,室温固化得到表面含有溴氰菊酯的蚊帐,该蚊帐具有驱蚊效果。利用紫外可见吸收光谱可以非常简便地测定蚊帐中溴氰菊酯含量。 相似文献
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考察了一缩二乙二醇(又名二甘醇DEG)在近临界水体系中两种不同添加物存在下的反应活性,并测定了在不同时间、温度、物料/水比、压力以及添加物浓度下二甘醇脱水环化产物-1,4-二氧六环(Dioxane)的产率.实验结果表明,在无任何添加物存在的近临界水体系中,二甘醇可以进行环化脱水生成1,4-二氧六环,但产率相对较低.当温度为340℃,反应时间为240 min,1,4-二氧六环的产率仅为9.84 %(wt).向反应体系引入ZnCl2,所得1,4-二氧六环产率较纯水条件下有很大提高.在浓度为0.5 %(wt) 的ZnCl2 溶液中,当温度为340℃,反应时间为120 min,1,4-二氧六环的产率最高可达50.89 % (wt);在浓度为1.0 %(wt) ZnCl2 溶液中,相同反应温度和时间下,1,4-二氧六环的产率最高可达36.18 %(wt).在相同反应条件下,向反应体系中引入Na2CO3,二甘醇几乎没有转化,检测不到1,4-二氧六环.根据产物产率变化规律和传统条件下二甘醇脱水机理,提出了近临界水中引入少量添加物情况下DEG脱水反应可能的反应历程. 相似文献
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使用高效液相色谱测定了香精中甲醛的含量。香精中的甲醛经2,4-二硝基苯肼衍生化形成2,4-二硝基苯腙后,以乙腈提取,然后采用高效液相色谱测定。色谱柱:WatersNova-pakC18(4μm,3.9mm×150mm);柱温:30℃;流动相∶乙腈-水(体积比为45∶55);检测波长352.0nm;运行时间:9min;流速:1mL/min。甲醛在0.01~10μg/mL范围内呈良好的线性关系,相关系数为0.9998,回收率在96.6%~107.9%范围内,相对标准偏差为2.7%,检测限为26.4ng/g。该方法可满足香精中甲醛的检验工作。 相似文献
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反相高效液相色谱法测定化妆品中防腐剂 总被引:3,自引:2,他引:3
采用反相高效液相色谱法测定化妆品中山梨酸、苯甲酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯和对羟基苯甲酸丁酯等6种防腐剂,用ZorbaxODS(5μm,4 6mmi d ×150mm)柱,V(磷酸二氢钾)∶V(乙腈)为90∶10作流动相,加入磷酸调pH值为2 0,检测波长为254nm。样品用乙醇-水-冰乙酸(体积比为70∶29 5∶0 5)提取,回收率为90 8%~105 7%,相对标准偏差为3 1%~8 5%。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria. 相似文献
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively.
There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized.
High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without
the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of
fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to
achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic
SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve
F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender
particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing,
and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing
or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually
preserves suspension stability during freezing.
Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago,
IL. Tied for first place in The John A. Gordon Best Paper Competition. 相似文献
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Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US
In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae
and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted
in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures
(release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species
(Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species
to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were
exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of
separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles
from the southeastern region of the US. 相似文献
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Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed. 相似文献
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
收集了2007年7月~2008年6月世界塑料工业的相关资料,介绍了2007~2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍. 相似文献
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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
收集了2005年7月~2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、通用热固性树脂(酚醛、聚氨酯、不饱和树脂、环氧树脂)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。 相似文献