降温速率对浮法硼硅酸盐玻璃下表面渗锡的影响

研究锡槽中降温速率对浮法硼硅酸盐玻璃下表面渗锡的影响.采用不同降温速率制备浮法硼硅酸盐玻璃,用电子探针测试浮法硼硅酸盐玻璃在1 250～650℃温度范围内不同降温速率情况下表面渗锡分布情况.研究结果表明:浮法成形过程中硼硅酸盐玻璃渗锡的深度可达到40.0μm左右,并且在1 050℃以上的高温段锡离子以深度方向扩散为主,在1 050℃以下的低温阶段锡离子主要在玻璃的近表面富集.随着时间的延长浮法硼硅酸盐玻璃近表面的渗锡量增加,而深度大于7.0μm以上的内部的渗锡量不会由于时间的延长而累加,只与温度有关.在浮法成形过程中渗锡曲线会在1 050℃左右,距玻璃表面15.0μm处出现卫星峰,但最终在低温时该卫星峰会由于逆扩散而消失.     

浮法玻璃渗锡问题分析及相应措施

浮法玻璃渗锡问题严重限制了我国浮法玻璃在玻璃深加工领域中的应用和发展。通过分析热加工虹彩现象和离子强化玻璃翘曲现象及浮法生产工艺中渗锡影响因素和测试方法,提出了监控锡槽内气体和锡槽密封性的必要性以及准确及时有效测试渗锡量和渗锡分布的重要性。     

浮法玻璃下表面富锡层的某些特点

在浮法成型过程中,由于锡液中含有氧而大大加捉了锡向玻璃的下表面(即与锡液接触的一面)扩散.近年来,国内外的浮法工作者在如何减少锡槽内的氧含量方面作了大量的研究,希望尽量降低锡向玻璃的扩散.正是由于浮法玻璃表面有一层富锡层,使浮     

浮法玻璃表面渗锡的系统性治理

浮法玻璃在锡槽内产生的表面渗锡缺陷是制约玻璃产品应用范围以及影响玻璃光学性能的重要因素。通过研究锡槽密封材料、锡槽内压力、保护气分配、锡液温度、锡槽附属设备配置等因素对玻璃表面渗锡量的影响,总结出浮法玻璃表面渗锡的系统性治理办法,达到降低玻璃表面渗锡拓展产品应用范围的目的。     

浮法成型过程中玻璃带降温速率控制

主要对玻璃带在锡槽内自然温降曲线的形成进行分析,阐述了拉引量、玻璃带运行速度、槽体散热、保护气体分布、锡液流动、拉边机参数与玻璃带降温速率的关系。分析了玻璃带降温速率对玻璃成型的影响,提出了通过锡槽结构和成型工艺参数设计控制温降曲线的方法和途径。浮法成型过程中,玻璃带温度由1 100℃左右降低至600℃左右,在整个降温过程中,温降曲线的控制是生产优质浮法玻璃的关键技术之一,建立合理的成型温降曲线可有效控制玻璃厚薄差和退火质量,提高玻璃带运行的稳定性。     

锡槽耗锡量问题研究与分析

通过研究浮法生产过程中锡槽的耗锡量问题,分析锡耗产生的主要原因,找到锡耗与玻璃生产质量之间的关系。通过对生产数据的收集和分析,发现耗锡量与玻璃渗锡量、流道温度、氢气使用量、二氧化硫使用量、槽压等因素的变化关系,并通过理论计算确认耗锡量的主要组成。结果表明：玻璃的渗锡是造成锡耗的最主要原因,在流道温度较低及渗锡量较低时,锡槽的锡耗会明显下降,同时在锡槽压力越高、氢气含量越高、锡槽出口二氧化硫用量越低的情况下,锡液的污染就越少,玻璃的耗锡量也随之减少,玻璃的成品率及质量也越好。     

浮法玻璃表面化学组成对玻璃性能的影响——浮法玻璃上下两表面的物理和化学性质有明显的不同

在用浮法工艺生产平板玻璃的过程中,玻璃带的上下两表面处在两种明显不同的介质中.当玻璃带通过锡槽时其下表与熔融锡液接触.玻璃与锡液之间相互作用的程度与玻璃在锡槽中的温度和时间以及锡槽中微量杂质的含量有关.玻璃带上表面在一特定高的温度下暴露在氮氢混合气体中.该还原气     

硼硅酸盐玻璃与钠钙硅玻璃浮法成型的对比研究

总结了浮法成型工艺的特点,介绍了浮法工艺对普通钠钙硅玻璃的要求,在此基础上提出从玻璃的熔化和成型温度要求,粘度-温度曲线要求,析晶温度上限要求等几个方面探讨耐热高强硼硅酸盐平板玻璃浮法成型的要求.     

渗锡量的定性检测及降低玻璃表面渗锡量的措施研究

浮法工艺生产平板玻璃,由于玻璃在锡槽内成形,玻璃下表面必然会引入一定的渗锡量,当渗锡量达到一定程度时,如果玻璃进行钢化加工,就会出现钢化彩虹,从而影响到玻璃的外观质量.分析了浮法玻璃钢化彩虹的形成与渗锡量的关系,提出了浮法玻璃生产中渗锡量的定性快速检测方法,可以避免玻璃在后续加工中造成损失;论述了降低玻璃渗锡量的措施,可用于指导浮法玻璃生产.     

锗对浮法玻璃下表面离子扩散影响的研究

利用浮法玻璃锡槽模拟装置,研究在锡槽中添加锗元素对玻璃下表面离子扩散的影响.通过X射线能谱仪(EDS)、X射线光电子能谱(XPS)测试手段对所得玻璃样品表面进行分析.结果表明:当锡液中添加0.02％锗元素时,玻璃样品下表面渗锡量与纯锡液上所得到的玻璃样品的渗锡量相比,降低3.74％.同时发现,渗入玻璃表面的锗主要以Ge4+为主.     

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。