共查询到20条相似文献,搜索用时 904 毫秒
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采用改进的Ross-Miles法研究了4种不同烷基链长的可断键均三嗪脂肪磺酸盐表面活性剂(OSEAT、DSEAT、TSEAT、HSEAT)的泡沫性能,考察了质量浓度、温度、Ca2+浓度对它们泡沫性能的影响。结果表明,OSEAT的抗钙能力最强,其起泡性和稳泡性几乎不受Ca2+浓度的影响;DSEAT的起泡性最好,在0.46 g/L时达到最大发泡力185 mm,且抗温能力强,当Ca2+浓度小于200 mg/L时,其抗钙能力比较强;TSEAT的起泡性较好,且具有一定的抗温、抗钙能力;HSEAT在水溶液中稳泡性最优,其发泡力随温度的升高而增大,55℃时达到最大值144 mm。与普通表面活性剂C12-LAS的泡沫性能比较,DSEAT发泡能力比C12-LAS强,泡沫稳定与C12-LAS接近。 相似文献
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采用脂肪醇聚氧乙烯醚、顺丁烯二酸酐和反丁烯二酸为主要原料合成了系列羧化对称型脂肪醇聚氧乙烯醚马来酸双酯Gemini表面活性剂,并将其作为棉织物的低温精练助剂。探讨了不同聚氧乙烯醚链段和不同脂肪链端基的双子表面活性剂用作精练剂的效果,结果表明羧化对称型月桂醇聚氧乙烯醚(9)马来酸双脂双子表面活性剂(DLEO9)的效果最好。详细研究了该双子表面活性剂对棉织物精练时温度、时间、碱和表面活性剂用量与失重和毛效之间的关系,精练后布样的失重率随精练温度的提高而增大,但毛细管效应随温度变化不同。最佳的精练工艺为:温度为85℃,时间为120 min,NaOH质量浓度为20 g/L,DLEO9质量浓度为1 g/L,浴比为1∶30。在相同条件下,DLEO9的精练效果优于常用的渗透剂JFC。 相似文献
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采用孔径为4 nm的陶瓷膜去除水中的Ca2+,考察了不同Ca2+含量、跨膜压差、溶液pH和温度对陶瓷膜渗透通量和Ca2+截留率随时间的变化情况。结果表明,溶液中的Ca2+含量越低,膜渗透通量越高,Ca2+截留率也越高;跨膜压差升高,膜渗透通量增大,Ca2+截留率降低;降低溶液pH及升高温度能够提高膜渗透通量及对Ca2+的截留率。对Ca2+的质量浓度为10 mg/L的水溶液,在TMP为0.1 MPa、溶液pH为3、温度为50℃时、孔径为4 nm陶瓷膜渗透通量稳定在80 L/(m2.h),Ca2+截留率为85%左右。研究结果可为金属离子微污染水的净化提供方法。 相似文献
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以玉米淀粉为原料,顺丁烯二酸酐为酯化剂,脂肪酶Novozym 435为催化剂,在低共熔溶剂中合成了顺丁烯二酸酐酯化淀粉.通过傅里叶变换红外光谱和核磁氢谱测试证实了酯化淀粉的生成.同时,研究了反应温度对酯化淀粉取代度的影响.GPC测试结果表明,改性之后的酯化淀粉分子量明显提高.X射线衍射分析表明,酯化反应破坏了玉米淀粉的晶型和降低了淀粉的结晶度.差示扫描量热(DSC)证实,酯化淀粉结晶温度降低以及结晶度下降.扫描电镜结果表明,酯化反应导致淀粉颗粒表面粗糙,颗粒尺寸增大并呈现不规则形状. 相似文献
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采用搅拌球磨机对木薯淀粉进行机械活化,以活化60min的木薯淀粉为原料,CuSO4 为催化剂,H2O2为氧化剂干法制备氧化淀粉,考察了活化时间、氧化淀粉浓度、pH.温度、钙离子浓度、时间等因素对木薯淀粉氧化产物阻碳酸钙垢性能的影响.结果表明,机械活化对木薯淀粉氧化产物的阻垢率有显著的影响.活化60min的木薯淀粉的氧化产物在氧化淀粉浓度10.0 mg-L-1;pH7.0.温度80℃,Ca2+离子质量浓度500.0 mg-L-1恒温时间10.0h的条件下阻垢率为93.5%,而在相同条件下,原木薯淀粉氧化产物的阻垢率仅为22.4%.并就机械活化木薯淀粉氧化产物阻碳酸钙垢的机理进行了探讨. 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