负载型二氧化钛光阳极对碱性紫5BN的光电催化降解

采用溶胶-凝胶拉提法在多孔泡沫镍基片上制备了纳米TiO2薄膜光阳极。利用自制反应器，对碱性紫5BN在固定态TiO2薄膜光阳极上的催化降解进行了研究。考察了外加电压、初始pH值、外加氧化剂对目标物质降解效率的影响。实验结果表明：制备的光催化剂具有良好的催化活性，通过XRD表征发现所制备的TiO2均为锐钛矿型；外加1．0V阳极电压时光电催化降解效果最好；初始pH为碱性时可以更好地进行降解：在酸性初始条件下降解效率反而有所降低；外加氧化剂对降解反应起到了增效作用；外加电压和氧化剂大大增加了降解反应的动力学速率常数。     

TiO_2光催化甲基橙电化学阻抗法表征的研究

采用溶胶-凝胶法在Al2O3薄膜表面上制备了纳米TiO2光催化薄膜(TiO2/Al2O3),将此薄膜用于光催化降解甲基橙,采用电化学阻抗法分析了TiO2薄膜光电极在甲基橙溶液中暗态、光照、不同光强以及改变阳极偏压时的交流阻抗图谱。结果表明,电化学阻抗谱能够较好的反应光催化、光电催化降解甲基橙的实验过程;并且发现施加阳极偏压可提高薄膜的催化性能,发现0.4 V左右最佳。     

光电催化降解活性蓝染料的研究

以液相沉积法在不锈钢片上沉积TiO2薄膜,以该TiO2/不锈钢片作为光阳极,Pb为阴极,采用单槽反应器和双槽反应器,研究了水中活性蓝染料的光电催化降解行为。结果表明,光电降解有机染料时,外加阳极偏压可提高TiO2薄膜电极的光催化活性。在相同的气氛下,活性蓝在双槽反应器的光电催化反应速率大于单槽反应器的反应速率;利用光电流的大小可以判断反应速率的快慢,本实验光电催化降解效率最大时,溶液的pH=7,阳极偏压为0.6 V,紫外光照射下两槽中通入空气。     

TiO2光催化薄膜的制备及其性能

在稀硫酸溶液中的阳极氧化钛箔,采用混合增长模型技术控制氧化膜的生长,制备了TiO2光催化薄膜.TiO2薄膜通过苯酚的光催化降解实验检验,具有较高的催化活性及很好的催化稳定性.实验结果表明阳极氧化法固定TiO2薄膜切实可行,不仅解决了TiO2微粒光催化过程催化剂微粒与水难分离的问题,而且阳极氧化制膜所需时间短(几秒到几分)、工艺简单,十分有利于工业化制备.     

ZnFe_2O_4和TiO_2纳米复合薄膜光电催化性能的研究

采用溶胶凝胶法,在导电玻璃上制备了纳米ZnFe2O4和TiO2的复合薄膜,利用X射线衍射仪及扫描电镜对其进行了表征,通过复合薄膜对甲基橙的降解试验研究了其光电催化性能及催化机理。并将复合薄膜、ZnFe2O4薄膜和TiO2薄膜在不同电压下的光电催化效果进行了对比,结果表明:复合薄膜的光电催化降解效率有了明显提高,三层复合薄膜ZnFe2O4+TiO2+ZnFe2O4的光催化效果最好,在外加偏压0.2-6V范围内随电压增大不同薄膜对甲基橙的降解率均呈现波动性增长。     

二氧化钛纳米管阵列制备和光催化降解亚甲基蓝

采用电化学阳极氧化的方法,以氟化铵水溶液为电解液,在纯钛表面制备了TiO2纳米管阵列。以亚甲基蓝为模拟污染物,考察了TiO2纳米管阵列光催化降解效果。结果表明,TiO2纳米管阵列催化降解效果要好于TiO2薄膜电极,当降解时间为1h、2h、3h和4h时,降解率分别为57.84%、86.44%、93.66%和95.72%;而TiO2薄膜电极的降解率分别为50.18%、76.27%、87.31%和91.53%。在此基础上,考察了阳极氧化电压、氧化时间和焙烧温度对阳极氧化过程的影响规律。结果表明,阳极氧化电压在25V,氧化时间在1h,焙烧温度在500℃时所制备的TiO2纳米管阵列的光催化降解性能最好。     

TiO2纳米管电极光电催化降解五氯苯酚

研究了阳极氧化TiO2纳米管电极对五氯苯酚(PCP)光催化降解,考察了外加偏压、pH、电解质Na2SO4浓度以及光强对PCP降解的影响。试验结果表明,当外加偏压增大到0.6 V时,PCP的去除率在2 h的反应时间从74%提高到87.5%;酸性溶液有利于PCP的降解;提高Na2SO4浓度有利于电子的转移,从而改善PCP光降解效率;光强越强,产生的空穴越多,就越有利于PCP的光电催化降解。     

TiO2光催化薄膜的制备及其性能

在稀硫酸溶液中的阳极氧化钛箔,采用混合增长模型技术控制氧化膜的生长,制备了TiO2光催化薄膜,TiO2薄膜通过苯酚的光催化降解实验检验,具有较高的催化活性及很好的催化稳定性,实验结果表明：阳极氧化法固定TiO2薄膜切实地,不仅解决了TiO2微粒光催化过程催化剂微料与水难分离的问题,而且阳极氧化制膜所需时间短（几秒到几分）、工艺简单,十分有利于工业化制备。     

二氧化钛纳米管阵列制备和光催化降解甲基橙

采用电化学阳极氧化的方法,以氟化铵水溶液为电解液,在纯钛表面制备了TiO2纳米管阵列。以甲基橙为模拟污染物,考察了TiO2纳米管阵列光催化降解效果。结果表明,TiO2纳米管阵列催化降解效果要好于TiO2薄膜电极,60、120和180 min时,降解率分别为56%、88%和100%;而TiO2薄膜电极的降解率分别为43%、76%和91%。在此基础上,考察了阳极氧化电压、氧化时间和焙烧温度对阳极氧化过程的影响规律。结果表明,阳极氧化电压在10～25 V,氧化时间在1～2 h,焙烧温度在500℃时所制备的TiO2纳米管阵列光催化降解性能最好。     

纳米TiO2膜电极光电催化降解污染物的研究进展

纳米TiO2基薄膜光电催化通过外加偏压阻止光生电子与空穴发生复合以提高光催化的量子效率,并使有机污染物发生深度矿化。本文详细介绍了光电催化的反应机理、TiO2基薄膜电极的制备及提高光电催化效率的主要途径、影响光电催化过程的主要因素等,最后对TiO2光电催化的发展方向进行了展望。     

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。