微波/过氧化氢降解水中苯酚

研究了在微波/H2O2辐射下苯酚溶液降解率,考察了影响微波/H2O2辐射降解苯酚溶液的各种因素.试验结果表明:苯酚降解率与溶液初始浓度、pH值、微波辐射时间和微波辐射温度等因素有关.随着微波温度的增加苯酚降解率呈线性增加.且初始溶液浓度愈高,苯酚降解量愈高.微波辐射时间愈长,苯酚降解率愈高.微波对苯酚的降解过程符合表观...     

超声/过氧化氢联合降解苯酚废水的研究

采用超声波/过氧化氢(US/H2O2)工艺对苯酚模拟废水进行了降解,考察了处理时间、苯酚溶液的初始pH值、初始浓度、反应温度等对降解效果的影响.实验结果表明:在单一超声波辐照或过氧化氢氧化下苯酚的降解率低,而两者联合降解效果明显提高,表明存在协同效应.在苯酚废水初始浓度为50mg/L、初始pH值3.01、反应温度25℃、处理时间180min在US/H2O2共同作用下,苯酚降解率为52.2%.苯酚在US/H2O2工艺中的降解反应符合表观一级反应动力学.     

自制氧化铅电极降解苯酚的试验研究

以钛片为基底,Sn O2+Sb2O5为中间层,自制氧化铅电极用于苯酚的电化学降解。试验结果表明,自制电极具有良好的苯酚去除效果:在室温为15℃,电极间距为15 mm,电流密度为16 m A/cm2,苯酚溶液p H为6.3,导电介质Na2SO4浓度为0.25 mol/L时,电解300 m L初始质量浓度为100 mg/L的苯酚,4 h后去除率可达91.89%。研究降解过程中苯酚初始浓度、p H、导电介质、电流密度、电极间距等因素对苯酚降解过程的影响。在此基础上对苯酚降解影响较大的初始浓度、p H、电流密度3个因素优化,通过响应曲面分析交互影响和单因素影响,结果表明,三者交互影响不大,苯酚初始浓度影响最大,p H影响最小,与单因素影响分析结果吻合。     

超声波降解水中苯酚的研究

分别研究了超声波、超声波/H2O2、超声波/Fenton试剂对苯酚降解率的影响.实验结果表明:对浓度为20 mg/L的苯酚水溶液超声波、超声波/H2O2、超声波/Fenton体系的降解率分别为10％、43％和58％.超声波可以提升H2O2和Fenton试剂的氧化效率.在超声功率为150W、超声时间为60 min,溶液p...     

旋转填充床中O_3/Fenton工艺处理模拟焦化废水

在旋转填充床(RPB)中,研究了O3/Fenton工艺处理模拟焦化废水的效果。考察了Fe2+浓度、旋转床转速、液体流量、气体流量及初始p H值对化学需氧量(COD)去除率及溶液中苯酚、苯胺、喹啉和NH3-N去除率的影响。结果表明,在p H值为6,温度25℃,液体流量20 L/h,气体流量5 L/h,转速1 000 r/min,H2O2的浓度为6.5 mmol/L,Fe2+浓度为0.4 mmol/L的条件下,模拟焦化废水的COD的去除率达到43.57%,废水中苯酚的去除率达81.56%,苯胺为100%,喹啉为81.17%,NH3-N为100%。     

超声波强化Fenton试剂法降解对硝基苯酚废水

通过超声波产生的空化效应,对Fenton试剂法降解对硝基苯酚(PNP)进行了强化。研究了声强、溶液初始pH、H_2O_2的浓度等因素对超声波强化Fenton试剂法(US/Fenton)降解对硝基苯酚的影响。结果表明,随着声强和H_2O_2浓度的增大,PNP的降解率增大;较低的pH有利于US/Fenton法降解对硝基苯酚。在充分利用超声空化产生的特殊反应环境的同时,提高了Fenton试剂对PNP的降解效果。     

超声波强化Fenton试剂法降解对硝基苯酚废水

通过超声波产生的空化效应,对Fenton试剂法降解对硝基苯酚(PNP)进行了强化。研究了声强、溶液初始pH、H_2O_2的浓度等因素对超声波强化Fenton试剂法(US/Fenton)降解对硝基苯酚的影响。结果表明,随着声强和H_2O_2浓度的增大,PNP的降解率增大;较低的pH有利于US/Fenton法降解对硝基苯酚。在充分利用超声空化产生的特殊反应环境的同时,提高了Fenton试剂对PNP的降解效果。     

超声波降解苯酚废水的研究

利用超声及超声组合技术降解含酚废水,实验中研究了苯酚初始浓度、声强及H2O2浓度等组合技术对超声降解苯酚反应的影响。结果表明在初始浓度为25 mg/L,H2O2的添加比例为1.0%、超声声强为4.97 W/cm2,催化剂添加量为1.0 g/L的条件下能有效降解苯酚,反应4 h后测得苯酚降解率为89.52%。     

非均相UV/Fenton催化降解苯酚研究

研究了UV/H2O2/改性海藻酸铁非均相催化降解苯酚时H2O2的投加量、溶液初始pH、苯酚初始浓度、改性海藻酸铁的含铁量等因素对苯酚降解率的影响.结果表明:该非均相体系在pH 2.0～11.1范围内都能高效催化氧化降解不同浓度苯酚废水.在基准条件下,若增加改性海藻酸铁的含铁量,则在反应时间2 min时,苯酚降解率可接近100%;以日光代替紫外光,苯酚降解率仍可达68.9%.     

紫外光-超声波耦合降解水溶液中苯酚和氯苯的研究

选取苯酚和氯苯分别作为亲水性和疏水性有机物代表,研究了紫外光、超声波和紫外光-超声波耦合3种降解方式、初始p H和初始浓度对苯酚和氯苯降解的影响。结果表明:苯酚紫外光降解效果更优,而氯苯超声波降解效果更优,两者耦合比单独使用降解效果更好。在中性条件下,苯酚的降解率最大;溶液的初始p H对氯苯降解率的影响不明显。2种有机物的降解与初始浓度呈负相关性,在同一浓度下,苯酚降解效果较优。     

Insect antifeedant properties of anthranoids from the genusVismia

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.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

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.     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

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.     

2005～2006年国外塑料工业进展

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。     

2007～2008年世界塑料工业进展

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.