掺杂纳米TiO2在难降解废水处理中的研究进展

掺杂可有效改善纳米TiO2的光催化活性及其光利用率,利于光催化技术在工业生产中的应用推广.介绍了掺杂纳米TiO2的光催化机理,总结了常见的掺杂纳米TiO2的制备方法:溶胶-凝胶法、浸渍法等.阐述了TiO2光催化技术在印染废水、农药废水、造纸废水及工业无机废水处理中的应用,并进一步分析了该研究领域所存在的问题,为今后光催化技术的发展方向提出展望:寻求新的掺杂离子、研制掺杂负载型纳米光催化剂和加强降解机理研究等.     

纳米TiO_2改性方法的研究进展

TiO2在利用光能和环保等领域具有重要应用前景。针对近年来纳米TiO2研究的新成果,对纳米TiO2的制备方法、光催化反应机理做了简要阐述,重点介绍了目前在纳米TiO2掺杂改性方面,尤其是非金属掺杂和共掺杂改性方面的研究进展。指出了TiO2研究进程中存在的主要问题、发展前景及今后的研究方向。     

纳米TiO2光催化降解有机废水及改性研究进展

纳米TiO2是近年来半导体材料用于环保领域中研究最多、最具发展前景的高新技术材料之一.作者介绍了纳米TiO2的光催化机理,并对纳米TiO2在降解有机废水等方面的应用进行了评述,还综述了近年来对纳米TiO2改性方面的研究,包括沉积贵金属、金属离子掺杂、非金属掺杂和半导体复合等技术.     

纳米TiO2的光催化活性及其在废水处理中的应用进展

综述了纳米TiO2光催化降解废水中有机污染物的机理,对影响二氧化钛光催化活性的各种因素,催化剂的形态,其他物质的掺杂、负载,溶液的pH值、光源与光照强度等进行了讨论,阐述了TiO2光催化氧化在水处理中的应用进展.展望了纳米TiO2在降解废水处理中的应用前景,提出了研究发展方向.     

Ag掺杂TiO2纳米薄膜光催化活性研究进展

TiO2在光催化和光电转化领域拥有十分广阔的应用前景,近几年来备受研究人员广泛关注.本文综述了TiO2光催化反应机理以及掺银TiO2纳米薄膜的制备方法,其中包括溶胶凝胶法、微乳液法、电弧溅射法、阳极氧化法以及表面化学反应等.主要讨论了Ag单掺杂和Ag与其他元素共掺杂的TiO2纳米薄膜光催化活性的研究进展,并对二者进行比较,展望了其发展方向.共掺杂TiO2纳米薄膜因比单掺杂薄膜具有更优异的光催化性能,是未来的主要研究方向之一.     

纳米TiO2在废水处理中的光催化活性

介绍了纳米TiO2光催化降解废水中有机污染物的机理,系统评述了纳米TiO2的粒径、晶型、掺杂、负载和废水处理体系中催化剂投加量、pH值、外加氧化剂、无机盐及光强等因素对其催化活性的影响。展望了纳米TiO2在降解工业废水处理中的应用前景,认为：提高纳米TiO2的光催化效率,扩展纳米TiO2的吸收光谱范围和开发纳米TiO2的负载技术是光催化法处理废水应用研究领域今后的主要发展方向。     

气相火焰燃烧合成锌掺杂TiO2纳米晶的光催化性能

以四氯化钛和乙酰丙酮锌为原料,采用气相火焰燃烧合成锌掺杂TiO2纳米晶,利用XRD, XPS和ICP-AES研究了纳米晶结构,考察了锌掺杂TiO2纳米晶在紫外光辐照下催化降解罗丹明B(Rhodamine B)的活性,探讨了光催化机理. 研究结果表明,掺杂相锌主要分布在TiO2表相,并形成均匀分散的ZnO团簇;燃烧过程中锌掺杂对纳米TiO2的晶相组成及晶粒尺寸影响不大. 当掺杂量为0.21%(mol)时,样品具有最高的光催化活性. 光催化机理分析表明,TiO2与ZnO不同的能带位置使光生载流子能够有效分离,改善了纳米TiO2光催化活性.     

提高纳米二氧化钛可见光光催化活性研究的进展

综述了近年来提高纳米TiO2可见光光催化活性的研究,主要包括:对纳米TiO2进行表面复合与衍生、金属离子掺杂、半导体偶合、非金属元素掺杂改性和染料敏化等技术,并分析了各种不同掺杂改性机理.最后,展望了提高纳米TiO2可见光光催化活性研究进展的前景.     

改性TiO2负载活性炭纤维的研究进展

综述了纳米TiO2光催化剂的4种改性方法：贵金属沉积法、离子掺杂法、复合半导体法和表面光敏化法及改性机理,并总结了改性TiO2在活性炭纤维表面的负载工艺研究进展,为今后改性TiO2光催化复合材料的发展提出了建议,旨在为以改性TiO2为基础的新型光催化材料的研究提供思路。     

改性TiO_2负载活性炭纤维的研究进展

综述了纳米TiO2光催化剂的4种改性方法:贵金属沉积法、离子掺杂法、复合半导体法和表面光敏化法及改性机理,并总结了改性TiO2在活性炭纤维表面的负载工艺研究进展,为今后改性TiO2光催化复合材料的发展提出了建议,旨在为以改性TiO2为基础的新型光催化材料的研究提供思路。     

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.     

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.     

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。