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以MgCl2-6H2O、CaCO3和LiCl为原料,采甩熔盐法制备了MgO粉体。通过热重.差示扫描热量计(TG—DSC)、X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)等手段对反应过程及产物进行了分析和表征,同时采用水解动力学分析法研究了煅烧温度和时间对氧化镁粉体活性的影响。TG-DSC分析表明,650℃时CaCO3可完全反应;XRD分析表朝,450℃保温3h热处理,产物中有MgO生成。650℃保温3h热处理,产物经无水乙醇洗涤后,全部为MgO晶体;SEM分析表明,所制备的氧化镁形貌为颗粒状,形状不规整,大小介于50-250nm之间;水解动力学分析法表明,当温度大于500℃、保温时阕超过3h后,随着热处理温度的升高和时间的延长,MgO粉体活性下降。 相似文献
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以MgCl_2·6H_2O、CaCO_3和LiCl为原料,采用熔盐法制备了岩层形貌MgO粉体.借助热重-差示扫描热量计(TG-DSC)、X射线衍射仪(XRD)、场发射扫描电子显微镜(SEM)等手段对反应过程及产物进行了分析和表征.结果表明,430 ℃保温3 h热处理,产物中有MgO生成,600 ℃保温3 h热处理,产物经无水乙醇洗涤后,全部为MgO晶体;原料在650 ℃下保温3 h热处理,用水浸泡得到的氢氧化镁为不规整的片状形貌,分解为氧化镁后变成颗粒状形貌,粒径介于0.1~0.6 μm之间;EDTA-PEG溶液浸泡得到的氢氧化镁为四面体形貌,分解为氧化镁后为岩层形貌,大部分在顶角处有缺损,最大边长可达1.5 μm,表层粘附着少量颗粒状氧化镁,表面不平整. 相似文献
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用柠檬酸法和XRD法测定氧化镁的活性,得到氧化镁活性与煅烧温度和煅烧时间的关系。用菱镁矿煅烧制备的氧化镁进行湿法烟气脱硫试验,结果表明,当煅烧温度为650℃、煅烧45min时,氧化镁活性最好,在650℃下煅烧45min和700℃下煅烧30min时的氧化镁的脱硫活性好。 相似文献
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均匀沉淀法制备锡酸锌与锡酸锌包覆纳米碳酸钙的研究 总被引:1,自引:0,他引:1
以均匀沉淀法制备了羟基锡酸锌和羟基锡酸锌包覆纳米碳酸钙,利用超声分散和共沸蒸馏对所得产物处理后,经高温煅烧得锡酸锌包覆纳米碳酸钙粉体.采用XRD,TG-DTA对羟基锡酸锌及羟基锡酸锌包覆纳米碳酸钙的煅烧产物进行分析,确定合成锡酸锌和锡酸锌包覆纳米碳酸钙的最佳煅烧温度为500 ℃,最佳煅烧时间为3 h.X射线光电子能谱(XPS)分析表明,锡酸锌已包覆在纳米碳酸钙表面,透射电子显微镜(TEM)结果表明,锡酸锌包覆纳米碳酸钙的粒径在40~60 nm. 相似文献
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《耐火材料》2017,(4)
为探讨悬浮态煅烧菱镁矿制备高活性轻烧氧化镁的可行性,将粒度74μm的菱镁矿粉放置于实验室自行研制的小型模拟悬浮态煅烧装置内煅烧,在温度分别为650、750、850和950℃,保温时间分别为30、60、180和300 s的条件下对菱镁矿进行快速煅烧而制备轻烧氧化镁,采用XRD、SEM分析煅烧产物的物相组成和显微结构,根据Scherrer公式计算MgO晶粒的尺寸,通过柠檬酸显色法分析MgO活性。结果表明:采用悬浮态煅烧菱镁矿可在短时间内制备出高活性轻烧氧化镁;煅烧温度为850℃、保温时间为180 s时制备出的MgO活性最高,其活性指数为3.33,柠檬酸显色时间为30 s。 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