超细BaTiO3粉体成瓷技术研究

基于液相化学共沉淀法合成超细ＢａＴｉＯ３粉末，研究了制备ＰＴＣ ＢａＴｉＯ３陶瓷的成瓷技术。利用ＸＲＤ和ＳＥＭ分析手段，对制备的ＢａＴｉＯ３陶瓷的结构进行了表征。对于影响ＢａＴｉＯ３陶瓷的主要性能，如致密化、ＰＴＣ效应和半导化性能的工艺参数进行了较为详细的研究和讨论。     

液相原料制备PTC粉体及其性能研究

本文介绍了一种通过液相原料形式引入以草酸盐共沉淀来制备ＰＴＣ粉体的新方法。即ＢａＴｉＯ３、Ａｌ２Ｏ３、ＳｉＯ２、ＭｎＯ２、Ｙ２Ｏ３等均采用液相原料引入，然后用草酸进行共沉淀，通过灼烧制得ＰＴＣ粉体。用这种粉体制得的ＰＴＣ陶瓷，其晶粒均匀性和电性能都优于传统固相法制得的ＰＴＣ陶瓷。     

双受主掺杂BaTiO_3基PTC陶瓷性能的研究

本文系统地研究了Ｆｅ~（２＋）、Ｍｎ~（４＋）复合受主掺杂和烧结工艺对ＢａＴｉＯ_３基ＰＴＣ陶瓷性能的影响， 通过不同复合受主掺杂量和不同烧结工艺，测试并整理了较大量的ＰＴＣ陶瓷材料的室温电阻及 其升阻比数据，旨在研究多受主掺杂和烧结工艺对瓷料性能的影响规律及寻找一种相应的最佳配 方和最佳烧结工艺，提高ＰＴＣ陶瓷的特性。     

多施主掺杂PTC陶瓷材料的研究

本文在双施主掺杂高ＴｃＢａＴｉＯ_３基ＰＴＣ陶瓷材料的基础上,对ＢａＴｉＯ_３的Ａ、Ｂ、Ｏ位同时进行离子置换以实现多施主掺杂,同时还研究了烧结温度对阻温特性的影响。研究结果表明,多施主掺杂试样的烧成温度对ｐ－Ｔ性能影响很大,在一定配方及工艺条件下,获得的ＰＴＣ陶瓷材料的室温电阻率变化不大,升阻比明显提高。     

钙掺杂对BaTiO3PTCR陶瓷性能的影响

钙参杂对ＢａＴｉＯ３ＰＴＣＲ陶瓷的微观结构和电性能具有显著的影响,钙掺杂有助于晶粒的均匀生长。少量钙掺杂对材料阻值及电性能影响不大。当钙掺杂达到一定时,材料的晶粒迅速减小,其电阻温度系数达到最大,室温电阻值增大。     

超细BaTiO3粉的液相合成技术研究

把快速混合技术运用于草酸盐沉淀法，制备了超细ＢａＴｉＯ３颗粒。运用ＸＲＤ，ＴＥＭ等测试手段，研究了制备超细ＢａＴｉＯ３粉末前驱体的液相合成工艺条件，过程规律及相应的表面处理技术。     

Nd2O3掺杂BaTiO3陶瓷的结构和电性能研究

研究了组份为Ｂａ１－ｘＮｄｘＴｉＯ３（ｘ＝０．００２－０．０４）陶瓷的结构和电性能，实验结果表明：当０．００２≤ｘ≤０．００４时，轻度Ｎｄ２Ｏ３掺杂的ＢａＴｉＯ３陶瓷呈半导体；而当０．０１２≤ｘ≤０．０４时呈绝缘性。ＢａＴｉＯ３陶瓷的室温电阻率ρｖ随Ｎｄ＾３＋含量的变化呈Ｕ型特曲线。组份为Ｂａ０．９９７０Ｎｄ０．００３０ＴｉＯ３的材料具有最低的ρｖ和最佳的ＰＴＣＲ效应，相应于最大的平均晶粒尺寸和最     

BaTiO3系PTCR材料电学性能的复阻抗解析

采用复阻抗解析法研究了ＢａＴｉＯ３系ＰＴＣＲ材料晶粒、晶界的电学性能。结果表明：使用欧姆接触电极的ＰＴＣＲ材料等效电路的复阻抗为：晶粒电阻呈ＮＴＣ特性，而晶界电阻天Ｔ〈Ｔｃ时呈ＮＴＣ特性，Ｔ〉Ｔｃ时呈明显的ＰＴＣ特性；ＰＴＣ效应是一种晶界效应。     

电子陶瓷粉BaTiO3的液相合成技术：Ⅱ前驱体草酸氧钛钡热分解机理研究

本文对液相合成ＢａＴｉＯ３的前驱体草酸氧钛钡采用ＩＲ、ＸＲＤ分析手段跟踪不同分解温度下其组分及晶型的变化规律，结合ＭＲ－ＧＣ、ＤＴＡ和ＴＧ等分析结果，阐述了草酸氧钛钡的热分解机理。分析结果表明前驱体在２００℃之前除四份结晶水成无定形，２２０－４７０℃时是无水草酸氧钡分解为ＢａＣＯ３和ＴｉＯ２并放出ＣＯ、ＣＯ２气体，７５０℃时是固相ＢａＣＯ３和ＴｉＯ２之间的反应生成立方晶型的ＢａＴｉＯ３，在１０００     

（Sr,Pb）TiO3陶瓷的PTCR现象

通过化学共沉淀工艺制备（Ｓｒ，Ｐｂ）ＴｉＯ３半导体陶瓷，首次获得了与ＢａＴｉＯ３陶瓷相类似的典型ＰＴＣ特性，样品耐压强度大，室温电阻率低于７０Ω·ｃｍ，升阻比超过１０＾６，烧结温度可以降低至１１００℃以下。     

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。