R2O-RO-B2O3-SiO2-Al2O3-P2O5-CaF2系分相-析晶乳浊釉的形成机理

通过正交试验方法优化釉料组成和烧成工艺,制备了R2O-RO-B2O3-SiO2-Al2O3-P2O5-CaF2多元系光亮无锆的分相-析晶乳浊釉.采用X射线衍射仪、透射电子显微镜/X射线能谱、场发射扫描电子显微镜等研究了釉的显微结构及分相与析晶的形成机理.结果表明:析晶与分相结构并存,分相促进析晶;尺寸接近可见光波长的孤立液滴和所析出的钙钠长石晶体是釉面产生乳浊的根本原因.研究了不同烧成制度对分相-析晶乳浊釉显微结构的影响,发现缓冷釉样的分相液滴尺寸明显大于急冷釉样,急冷釉样中的第二相形貌表里存在明显差异,内部呈球形液滴状,表面则为蠕虫状.     

R2O-RO-B2O3-SiO2-Al2O3-P2O5-CaF2分相-析晶乳浊釉的形成机理

通过正交试验方法优化釉料组成和烧成工艺，制备了R2O-RO-B2O3-SiO2-Al2O3-P2O5-CaF2多元系光亮无锆的分相-析晶乳浊釉。采用X射线衍射仪、透射电子显微镜／X射线能谱、场发射扫描电子显微镜等研究了釉的显微结构及分相与析晶的形成机理。结果表明：析晶与分相结构并存，分相促进析晶；尺寸接近可见光波长的孤立液滴和所析出的钙钠长石晶体是釉面产生乳浊的根本原因。研究了不同烧成制度对分相-析晶乳浊釉显微结构的影响，发现缓冷釉样的分相液滴尺寸明显大于急冷釉样，急冷釉样中的第二相形貌表里存在明显差异，内部呈球形液滴状，表面则为蠕虫状。     

组成对分相-析晶乳浊釉显微结构及表面性质的影响

采用X射线衍射、透射电镜和扫描电镜等测试手段,研究了不同组成对分相-析晶乳浊釉显微结构及釉面性状的影响.研究表明:B2O3和P2O5能促进分相形成,并且由于分相具有很小的表面张力而使其液滴易于长大.适量引入CaO能使液滴尺寸增大,体积分数提高,但过量引入会由于析晶而使体积分数降低.控制分相液滴尺寸接近可见光波长以及使釉中析出适量钙钠长石晶体可获得最佳的乳浊效果,而液滴过大或过小都难以获得较佳的乳浊效果.     

R_2O–RO–B_2O_3–SiO_2–Al_2O_3–P_2O_5–CaF_2系分相–析晶乳浊釉的形成机理

通过正交试验方法优化釉料组成和烧成工艺,制备了R_2O–RO–B_2O_3–SiO_2–Al_2O_3–P_2O_5–CaF_2多元系光亮无锆的分相–析晶乳浊釉。采用X射线衍射仪、透射电子显微镜/X射线能谱、场发射扫描电子显微镜等研究了釉的显微结构及分相与析晶的形成机理。结果表明析晶与分相结构并存,分相促进析晶;尺寸接近可见光波长的孤立液滴和所析出的钙钠长石晶体是釉面产生乳浊的根本原因。研究了不同烧成制度对分相–析晶乳浊釉显微结构的影响,发现缓冷釉样的分相液滴尺寸明显大于急冷釉样,急冷釉样中的第二相形貌表里存在明显差异,内部呈球形液滴状,表面则为蠕虫状。     

组成及工艺条件对分相/析晶乳浊釉乳浊行为的影响

以天然矿物原料为主要原料,通过合理的组成设计和工艺控制,使R2O-RO-Al2O3-SiO2-P2O5系釉在高温下发生分相和析晶,得到分相/析晶乳浊釉。XRD、SEM、EDS等测试技术研究表明:在高骨粉区域以分相乳浊为主,其连续相为富铝、硅贫磷的硅酸盐玻璃,分散相是富磷、锌、镁贫铝、硅的磷硅酸盐玻璃,分散相粒子粒度约为0.3～0.8μm,且分布均匀,釉面白度80%、光泽度101%;在骨粉和滑石均较高的区域,得到分相和析晶共存的乳浊釉,析出的晶体以原顽火辉石为主,釉面白度85%、光泽度98%。     

低温快烧自生微晶乳浊釉的研究

采用SEM、EDX、XRD等手段,研究了KNaO-MgO-Al2O3-B2O3-SiO2系全熔块乳浊釉的形成规律,指出釉层中均匀分布的大量MgSiO3微晶是釉面乳浊的原因.组成中B2O3含量愈高,釉熔体的析晶倾向愈大.少量Al2O3则可以降低釉熔体高温粘度,抑制析晶,改善釉面白度和光泽度.在釉烧过程中,析晶继续进行,B2O3含量的增加使基质釉玻璃的成熟温度降低.设计合理组成及快烧工艺,可得到釉面综合质量良好的微晶乳浊釉.     

液—液分相与乳浊釉

常用的乳浊釉就其乳浊机理而言可分为两大类。一是由于液一液分离在基质釉玻璃中分离出第二相,因两相的折射率不同导致乳浊称为分相乳浊;二是在基质釉玻璃中析出大量细小的晶体,由于晶相与玻相存在折射率差形成乳浊称为熔析乳浊。二者的乳浊效果都取决于两相的折射率差和分散相的尺寸及其在基质中的分布形态。不言而喻,分相乳浊的乳浊效果与分相的热力学、动力学及显微结构有着密切的关系。大量研究工作亦表明分相对玻璃中的析晶也有种种影响。本文旨在讨论液—液分离现象对常用乳浊釉乳浊效果的影响及如何根据分相原理和相图合理地选择釉组成,以获得良好的乳浊效果。     

R2O-RO-Al2O3-SiO2-P2O5系分相/析晶乳浊釉乳浊粒子的形成机理

在普通石灰碱釉的基础上引入骨粉和滑石,形成R2O-RO-Al2O3-SiO2-P2O5系统釉料,通过调整釉料的化学组成获得分相/析晶乳浊釉.利用XRD,SEM,EDS等测试技术,研究了SiO2与P2O5和SiO2与MgO的摩尔比与釉层显微结构的关系,分析了乳浊粒子(玻璃液滴和微晶)的形成机理.     

0.20R_2O-0.45CaO-0.35ZnO-Al_2O_3-SiO_2系统的相变

通过大量的配方实验 ,利用OM、TEM和XRD分析 ,研究了 0 .2 0R2 O - 0 .4 5CaO - 0 .35ZnO-Al2 O3-SiO2 系统的分相与析晶。研究结果表明 ,在Al2 O3含量高于 0 .30～ 0 .4 5mole的区域可以获得乳浊程度和光泽度各异的析晶乳浊釉 ,在低铝区可获得分相乳浊釉和分相玻璃 ,且乳浊程度随Al2 O3含量的降低、SiO2 含量的提高而提高。用Na2 O取代K2 O不利于系统的分相。试样中析出的晶体主要为硅锌矿、锌黄长石、白榴石和锌铝尖晶石。当R2 O全部由K2 O引入且Al2 O3含量较低时 ,主要为硅锌矿、白榴石和锌黄长石 ,Al2 O3 含量较高时则主要为白榴石、锌黄长石和锌铝尖晶石 ;用Na2 O等摩尔取代K2 O不利于白榴石和硅锌矿的析晶 ,而有利于锌黄长石的析晶 ;锌黄长石的析晶主要受组成的影响 ,对析晶保温温度不敏感。通过设计合理的配方、采用适当的烧成温度制度 ,可以获得结晶良好的析晶乳浊釉、分相乳浊釉、分相玻璃、硅锌矿或锌黄长石分相结晶釉或微晶玻璃。     

R_20-RO-Al_2O_3-SiO_2-P_2O_5系分相／析晶乳浊釉乳浊粒子的形成机理

在普通石灰碱釉的基础上引入骨粉和滑石,形成R2O-RO-Al2O3-SiO2-P2O5系统釉料,通过调整釉料的化学组成获得分相／析晶乳浊釉。利用XRD,SEM,EDS等测试技术,研究了SiO2与P2O5和SiO2与MgO的摩尔比与釉层显微结构的关系,分析了乳浊粒子(玻璃液滴和微晶)的形成机理。     

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.