钒-氮共掺杂TiO2光催化降解苯酚试验研究

采用溶胶-凝胶法制备了钒-氮共掺杂TiO2光催化剂,对苯酚溶液进行了光催化降解试验研究,考察了在模拟太阳光条件下,pH、曝气量、苯酚溶液初始和催化剂投加量对钒-氮共掺杂TiO2光催化剂降解苯酚溶液的影响。结果表明,在试验条件下,以800 W氙灯为光源,反应溶液pH=6,曝气体积流量75 mL/min,苯酚溶液初始质量浓度小于80mg/L,催化剂投加量1.5 g/L时,苯酚溶液降解率最高;钒-氮共掺杂TiO2光催化剂重复使用7次后,对苯酚的光催化活性没有明显下降,具有良好的重复使用性。可为钒-氮共掺杂TiO2的应用推广提供依据。     

固体超强酸SO2-4/TiO2-WO3光催化降解邻硝基苯酚动力学研究

在高压汞灯下,研究了邻硝基苯酚在SO4^2-/TiO2-WO3光催化剂表面的降解过程,对邻硝基苯酚在SO4^2-/TiO2-WO3悬浮体系中的降解机理进行了初步的探讨。结果表明,光降解反应速率受邻硝基苯酚的初始浓度、气相氧流量、反应温度、溶液pH值、光强度和催化剂用量等因素的影响。基于Langmuir-Hinshelwood方程和一些假设,分析了邻硝基苯酚光降解的动力学机理,推导了固体超强酸SO4^2-/TiO2-WO3催化邻硝基苯酚光降解的动力学方程。     

固体超强酸SO4^2-/TiO2-WO3光催化降解邻硝基苯酚动力学研究

在高压汞灯下,研究了邻硝基苯酚在SO4^2-/TiO2-WO3光催化剂表面的降解过程,对邻硝基苯酚在SO4^2-/TiO2-WO3悬浮体系中的降解机理进行了初步的探讨。结果表明,光降解反应速率受邻硝基苯酚的初始浓度、气相氧流量、反应温度、溶液pH值、光强度和催化剂用量等因素的影响。基于Langmuir-Hinshelwood方程和一些假设,分析了邻硝基苯酚光降解的动力学机理,推导了固体超强酸SO4^2-/TiO2-WO3催化邻硝基苯酚光降解的动力学方程。     

锶掺杂二氧化钛介孔材料的制备及其光降解邻硝基苯酚

采用固相法合成了锶掺杂二氧化钛(Sr-TiO2)介孔材料。采用XRD、TEM、UV-Vis、BET、Raman等测试手段对材料进行了详细表征,考察了材料对邻硝基苯酚的光催化活性。结果表明,Sr-TiO2材料为锐钛矿相,典型样品的BET比表面积为160.9 m2/g,孔径集中分布在7.2 nm处。锶的掺杂使TiO2晶体结构产生微小畸变,吸收带边发生红移;在紫外光照射下,Sr-TiO2对邻硝基苯酚的催化降解性能比纯TiO2有明显提高,2 h内光催化降解率达到98.2%。在邻硝基苯酚初始质量浓度为30 mg/L,催化剂投加量为1.2 g/L,光催化效率最高。     

固体超强酸SO_4~(2-)/TiO_2-WO_3光催化降解邻硝基苯酚动力学研究

在高压汞灯下,研究了邻硝基苯酚在SO42-/TiO2-WO3光催化剂表面的降解过程,对邻硝基苯酚在SO42-/TiO2-WO3悬浮体系中的降解机理进行了初步的探讨。结果表明,光降解反应速率受邻硝基苯酚的初始浓度、气相氧流量、反应温度、溶液pH值、光强度和催化剂用量等因素的影响。基于Langmuir-Hinshelwood方程和一些假设,分析了邻硝基苯酚光降解的动力学机理,推导了固体超强酸SO42-/TiO2-WO3催化邻硝基苯酚光降解的动力学方程。     

Fe~(3+)/TiO_2太阳光催化降解对硝基苯酚的研究

采用均匀沉淀法制备了铁掺杂TiO2催化剂粉体,利用XRD、TEM对粉体进行了表征。以太阳光为光源,研究了太阳光下光催化降解对硝基苯酚的可行性。结果表明,当Fe3+/TiO2摩尔比为1:1000,煅烧温度为400℃时,得到的复合光催化剂具有较高的光催化活性,在光催化反应240min的条件下,对硝基苯酚的降解率可达64.6%,其光催化活性要优于纯TiO2。     

光电催化降解硝基苯及反应产物的分布

采用溶胶-凝胶法制备TiO2薄膜光电极,作为工作电极,铂丝为对电极,饱和甘汞电极为参比电极,对硝基苯的光电催化降解进行了研究.结果表明：该电极具有n型半导体的特征行为.在外加偏压为＋0.6V、pH=1、50mg/L的H2O2中对初始浓度为50mg/L的硝基苯溶液光照120min降解率达6 5.68%.讨论了外加偏压、硝基苯浓度和pH值等因素对光电催化反应的影响,并且在硝基苯降解时所产生的中间产物中,可以检测到有邻硝基苯酚、对硝基苯酚、间硝基苯酚和硝酸根存在及其分布情况.     

SO_4~(2-)/TiO_2光催化降解邻硝基苯酚(英文)

采用硫酸溶液浸渍处理TiO2制得SO42-/TiO2光催化剂。考察了光催化剂对邻硝基苯酚溶液的光催化行为。发现SO42-/TiO2的光催化活性高于TiO2,浸渍液中H2SO4的浓度和催化剂的焙烧温度对SO42-/TiO2的催化活性有一定的影响,H2SO4溶液的最佳浓度为0.5 mol.L-1,最佳焙烧温度为500℃。催化降解过程符合一级反应动力学规律。     

Sn4+-TiO2的制备及其光催化降解邻硝基苯酚的研究

采用硬脂酸法制备出Sn4 -TiO2复合光催化剂,用X光衍射仪对粉体进行了必要的表征。样品经500℃焙烧2h后,5%(摩尔分数)Sn4 -TiO2纳米粉末的平均粒径约为14nm。通过粉体对邻硝基苯酚的降解情况对其光催化活性进行了测试,结果表明与纯TiO2相比,Sn4 -TiO2的光催化活性有较大提高,当SnO2的掺入量为摩尔比5.0%时催化活性最高。以高压汞灯为光源,邻硝基苯酚的初始浓度为50mg·L-1、催化剂5%(摩尔分数)Sn4 -TiO2投加量为1.0g·L-1时,邻硝基苯酚的光催化降解效果最好。     

Co~(2+)-TiO_2纳米粒子的制备及光催化性能研究

用溶胶-凝胶法制备Co2+-TiO2纳米粒子,利用X-射线衍射(XRD)、透射电子显微镜(TEM)和紫外-可见光谱(UV-vis)对样品进行表征。以对-硝基苯酚为目标降解物,考察了Co2+掺杂对纳米TiO2光催化活性的影响。结果表明,适量Co2+掺杂抑制了纳米TiO2晶粒的成长,使TiO2的光谱响应范围向可见光拓展,有利于提高TiO2的光催化活性,提高TiO2对太阳光的利用率;Co2+-TiO2能有效提高对-硝基苯酚的光催化降解,掺Co量(以摩尔计)不同的TiO2光催化活性依次为:0.5%>0.25%>0%>5%>10%。     

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。