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《化工学报》2016,(6)
掌握Fe~(2+)/H_2O_2体系O_2的生成路径,可为避免H_2O_2无效分解,开发经济高效的Fe~(2+)/H_2O_2体系利用技术指明方向。采用添加自由基捕获剂的方法,探究Fe~(2+)/H_2O_2体系内各种自由基对O_2生成速率的影响,进而确定O_2的生成路径。结果表明:Fe~(2+)/H_2O_2体系内不会产生大量O_2~-·,O_2~-·不是生成O_2的主要反应物质;·OH被全部捕获后,体系中仍产生大量HO_2·,但此时无O_2生成,证明生成O_2的反应由·OH和HO_2·两种自由基直接参与。分析认为反应·OH+HO_2=H_2O+O_2是Fe~(2+)/H_2O_2体系内O_2生成的主要路径。控制Fe~(2+)/H_2O_2体系定向生成·OH,抑制HO_2·的产生,是提高Fe~(2+)/H_2O_2体系中H_2O_2利用率的有效手段。 相似文献
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采用实验方法研究了不同尺寸滴管炉反应器内H_2O_2热分解氧化NO特性。对比了不同H_2O_2蒸发条件对NO氧化率的影响规律。分析了气体温度、H_2O_2溶液浓度、H_2O_2:NO摩尔比、NO初始浓度及气体流量对NO氧化率的影响。检测了氧化产物并分析了产物的生成路径。结果表明:H_2O_2的快速蒸发是其热分解氧化NO的前提。减小H_2O_2液滴尺寸或液膜厚度可加速H_2O_2蒸发与分解,提高NO氧化率,扩宽NO氧化的温度范围。保证蒸发速率可削弱H_2O_2浓度对NO氧化率的影响。当H_2O_2:NO10时,NO氧化率随H_2O_2:NO的增加而增加;当H_2O_2:NO10时,NO氧化率几乎不随H_2O_2:NO变化。H_2O_2热分解对于较高浓度的NO具有更高的氧化效率。H_2O_2热分解氧化NO的主要产物为NO_2。HO_2·直接将NO氧化为NO_2,·OH则先将NO转化为HONO,然后进一步氧化为NO_2。 相似文献
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介绍了含硅西佛碱的合成,制备了8种含硅西佛碱。用^1H—NMR、^13C—NMR对合成的化合物进行表征。目标分子为Ph—CH=NCH2CH2CH2Si(OCH2CH3)3;Ph—CH=NCH2CH2NHCH2CH2CH2Si(OCH2CH3)3;o-HO-Ph—CH—NCH2CH2CH2Si(OCH2CH3)3;o-HO-Ph—CH=NCH2CH2NHCH2CH2CH2Si(OCH2CH3)3;2,4-Cl-Ph—CH=NCH2CH2CH2Si(OCH2CH3)3;2,4-Cl-Ph-CH=NCH2CH2NHCH2CH2CH2Si(OCH2CH3)3;p-NO2-Ph-CH=NCH2CH2CH2Si(OCH2CH3)3;P-NO2-Ph-CH=NCH2CH2NHCH2CH2CH2Si(OCH2CH3)3。 相似文献
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用空气直接氧化硫化钠制取硫代硫酸钠的研究 总被引:3,自引:0,他引:3
生产硫代硫酸钠的方法很多。有硫化钠法、多硫化钠法、亚硫酸钠法、硫氢化钠法、硫化氢法等。它们的反应原理分别为: 2Na_2S+Na_2CO_3+4SO_2→3Na_2S_2O_3+CO_2↑2Na_2S_2+3Na_2CO_3+6SO_2→5Na_2S_2O_3+3CO_2↑2Na_2S_2+6NaHSO_3→5Na_2S_2O_3+3H_2O Na_2SO_3+S→Na_2S_2O_3 2NaHS+4NaHSO_3→3Na_2S_2O_3+3H_2O 2H_2S+2Na_2SO_3+2NaHSO_3→3Na_2S_2O_3+3H_2O 相似文献
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碱,Fe~(3+),Mg~(2+)对过氧化氢稳定性的影响 总被引:3,自引:0,他引:3
本文从印染漂白角度研究了碱、Fe3+、Mg2+对H2O2稳定性的影响。结果表明,碱浓度增大时,H2O2的稳定性是不单调降低;Fe3+对H2O2分解有明显催化作用;Mg2+对H2O2有良好稳定作用。解释了Mg2+稳定H2O2的原因。 相似文献
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O_2/N_2、O_2/CO_2和O_2/CO_2/NO气氛下煤粉燃烧NO_x排放特性 总被引:1,自引:0,他引:1
利用滴管炉研究了O2/N2、O2/CO2和O2/CO2/NO气氛下煤燃烧过程中NOx的排放特性。实验结果表明,在O2/N2和O2/CO2气氛下,高温或高O2浓度均使NO排放量增加。O2/CO2气氛下NO排放量比O2/N2气氛下NO排放量低大约30%~40%。在O2/CO2/NO气氛下,温度不同时,O2浓度变化对NO排放量的影响规律不同,对循环NO降解的影响规律也不同。高温不利于循环NO降解。随停留时间的延长NO排放量出现两个峰值。 相似文献
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以偶氮染料橙黄G(OG)为目标污染物,研究Fe2+分别催化H2O2、S2O82-、H2O2-S2O82-降解0.1 mmol/LOG Fe2+/H2O2体系,[Fe2+]=1 mmol/L,pH=3,[H2O2]0=10 mmol/L,降解30 min OG脱色率为96%,随着pH值增大和[H2O2]0>10 mmol/L,OG脱色率减小,呈线性变化。Fe2+/S2O82-体系,随着S2O82-初始浓度增加OG脱色率增大,随着pH值增大OG脱色率减小,呈非线性变化。Fe2+/H2O2-S2O82-体系,pH=3,[H2O2]0=2 mmol/L,[S2O82-]0>10 mmol/L时OG脱色率持续增大。Fe2+/H2O2-S2O82-体系矿化率最高。利用乙醇和硝基苯作为分子探针,采用分子探针竞争实验鉴定该体系中产生的SO4.和OH.。 相似文献
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SiO_2-ZrO_2-Na_2O 玻璃中 TiO_2对玻璃耐碱性的影响 总被引:1,自引:0,他引:1
本文研究了 TiO_2对国内外抗碱玻璃纤维中应用最广泛的 SiO_2-ZrO_2-Na_2O 系统玻璃耐碱性的影响。应用分光光度法分别测定了玻璃中三种主要氧化物siO_2、TiO_2和 ZrO_2转入 NaOH 侵蚀液中的量。讨论了 ZrO_2、TiO_2提高玻璃耐碱性的原因。结果表明,TiO_2具有耐碱性,三种主要氧化物的耐碱性序列为 ZrO_2>TiO_2>SiO_2。但当 TiO_2引入玻璃中将促使 SiO_2由玻璃向 NaOH 侵蚀溶液转入量的增加。使试样总失重略有增加。 相似文献
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1 前言 H_2O_2的稳定性受温度、pH值及某些阴阳离子的影响。关于重金属离子对H_2O_2稳定性的影响,国外已有不少报导。有关Mg~(2+)、Ca~(2+)、Sr~(2+)、Zn~(2+)、Cd~(2+)等二价阳离子对H_2O_2稳定性的影响未见报导。本文对H_2O_2初始浓度为0.05mol·L~(-1)、pH值为11.0时,相同浓度的Mg~(2+)、Ca~(2+)、Sr~(2+)、Zn~(2+)、Cd~(2+)在不同温度下对H_2O_2稳定性的影响效力及同一温度下不同浓度5种阳离子对H_2O_2稳定性的影响效力作了对比研究。为印染业 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