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1.
采用溶胶一凝胶法制备了负载于玻璃的CdO-TiO2复合光催化剂,并将其用于光催化降解染料酸性媒介红B。实验表明,n(Cd)/n(Ti)=0.04,涂覆5层,550℃煅烧0.5h的CdO-TiO2复合光催化剂活性最高,反应1h后的降解率是使用纯TiO2的3倍多。实验证明,该负载型光催化剂对染料酸性媒介红B的降解符合准一级动力学规律,常温(25℃)时反应的速率常数为0.0095min^-1,反应的活化能21.2KJ/mol。  相似文献   

2.
方彩霞  钱晓良  王奎 《工业催化》2004,12(11):37-40
以玻片为载体,采用溶胶-凝胶法制备了CeO2-TiO2复合光催化剂。采用XRD等对催化剂进行了表征。通过可溶性染料酸性媒介红B的微波辅助光催化氧化反应,考察了其光催化活性;并研究了复合催化剂的煅烧温度、铈掺杂量和涂覆次数等对催化活性的影响。实验结果表明,x(CeO2)=0.03%,涂覆次数为2次,在400 ℃焙烧2 h的CeO2-TiO2负载型光催化剂的活性最高。  相似文献   

3.
含钛和稀土高炉渣光催化降解活性艳红X-3B   总被引:8,自引:1,他引:7  
实验制备了含钛高炉渣/稀土渣复合光催化剂,负载于玻璃表面,通过对水溶液中活性艳红X-3B的降解实验,研究了含钛高炉渣/稀土渣复合光催化剂的光催化效果,评价了含钛高炉渣/稀土渣复合光催化剂性能与溶液的pH值、不同光源、空气流量及热处理温度的影响关系,并与纯TiO2光催化剂进行了对比实验。结果表明:经600℃处理的催化剂具有最好的光催化性,酸性条件、适当空气通人量、提高紫外光强度均有助于染料的降解。  相似文献   

4.
周建敏  胡相红  王键 《工业催化》2016,24(12):64-67
采用溶胶-凝胶法制备镱镧共掺杂二氧化钛光催化剂Yb-La/TiO_2,在紫外光照射下,以罗丹明B作为目标降解染料,考察催化剂的光催化性能。结果表明,制备Yb-La/TiO_2光催化剂的最佳条件为:n(La)∶n(Yb)∶n(Ti)=1.2∶1.0∶100,钛酸丁酯用量10 m L,无水乙醇用量50 m L,聚乙二醇用量0.4 g,冰醋酸用量2 m L,pH=2.3,陈化4天,150℃干燥24 h,550℃焙烧2 h。此条件下制备的Yb-La/TiO_2光催化剂对罗丹明B的降解率达93.37%,重复使用3次后,降解率仍高于80%。  相似文献   

5.
采用浸渍法制备出B、N和Ce共掺杂TiO2光催化剂,并用SEM等表征了其结构特征.以酸性大红染料溶液的光催化降解为探针反应,考察了制备条件对共掺杂TiO2催化剂活性的影响.结果表明,在600℃,当B、N和Ce的原子比为2:2:0.1,焙烧3 h时,光催化剂活性最大,大红染料的降解率达到90%.  相似文献   

6.
采用原位氧化还原法制备了三维石墨烯负载型Fe_3O_4(Fe_3O_4/3D GN)非均相Fenton反应催化剂,对其进行了表征,并用于酸性红B染料废水的Fenton氧化降解。表征结果显示:制备的Fe_3O_4/3D GN具有相互贯通的独特三维网状结构,Fe_3O_4纳米颗粒均匀分散在石墨烯片层中。实验结果表明:Fe_3O_4/3D GN具有较高的催化活性和稳定性。Fe_3O_4/3D GN非均相Fenton催化降解酸性红B的最佳工艺条件为:H2O2投加量0.67 m L/L,催化剂投加量1 g/L,初始溶液pH为6。在此最佳工艺条件下反应30 min,酸性红B染料废水的脱色率达到95.64%。  相似文献   

7.
钇掺杂TiO2/膨润土复合光催化剂降解染料X-3B的研究   总被引:2,自引:0,他引:2  
以膨润土为载体,钛酸四丁酯和氯化钇为原料,采用溶胶-凝胶法制备钇掺杂TiO2/膨润土纳米复合光催化剂,在太阳光照射下,通过染料活性艳红X-3B的降解反应,考察其光催化活性.实验结果表明:随着光照时间的延长,染料活性艳红X-3B的特征峰540 nm强度逐渐减弱,2 h后可彻底消失,脱色率达96.86%;染料活性艳红X-3B的降解速率随着外加氧化剂H2O2的增多而增大,但过量的H2O2也会抑制复合光催化剂的活性;在强酸和强碱条件下,染料活性艳红X-3B的降解率较高.  相似文献   

8.
从已运行一年的三相内循环好氧生物流化床系统中分离筛选出一株降解酸性红B的高效耐盐菌株BY-2,通过对菌株的理化形态特征及16s r RNA序列分析,初步确定菌株BY-2为Pseudomonas sp.属。考察了初始pH、盐度、染料浓度以及接种量等条件对酸性红B降解与菌体生长的影响。结果表明:初始pH为7,盐浓度为50 g×L~(-1),酸性红B初始浓度为500 mg×L~(-1),接种量2%,反应18 h时,酸性红B的降解率可达90%以上。降解中间产物的紫外-可见光光谱和GC-MS分析说明菌株BY-2对酸性红B有良好的降解作用,菌株BY-2在实际染料废水处理中具有潜在应用价值。  相似文献   

9.
采用溶胶-凝胶法制备了纳米TiO_2,合成了TiO_2/Cu_2O复合光催化剂,并对合成的TiO_2和TiO_2/Cu_2O进行SEM和XRD表征。在高压汞灯照射下,采用TiO_2/Cu_2O复合光催化剂对活性艳红X-3B进行光催化降解反应,考察了n(Ti~(4+))∶n(Cu~(2+))、pH、反应温度等因素的影响。结果表明,在高压汞灯照射下,与纳米TiO_2相比,TiO_2/Cu_2O的光催化降解效果得到明显提高。以0.01gTiO_2/Cu_2O复合物为光催化剂,在高压汞灯照射下,降解100mL20mg/L的活性艳红X-3B溶液,起始pH为1,水浴温度为60℃,反应60min,活性艳红X-3B最佳降解率为83.6%。  相似文献   

10.
以牡蛎壳为载体,采用超声浸渍法-焙烧制备牡蛎壳负载铜的催化剂,利用电镜扫描(SEM)、X射线衍射(XRD)对催化剂进行表征。以酸性红FRL为降解目标物,研究此催化剂催化过硫酸钠降解酸性红FRL的性能。考察了催化剂焙烧的条件、氧化剂浓度、催化剂用量和初始染料浓度对降解的影响。结果表明,催化剂经500℃焙烧3 h,催化活性较高;当初始污染物浓度为120 mg·L-1,氧化剂浓度为0.28 g·L-1,催化剂用量为0.70 g·L-1时,降解2.5 h,酸性红FRL染料溶液的降解率可达80.3%以上。  相似文献   

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12.
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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14.
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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17.
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   

18.
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   

19.
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   

20.
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   

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