板式塔降液管的机械消泡研究

研究开发了板式塔降液管机械消泡板组件。在降液管中加设特制的新型消泡板组件,该组件由数列若干块相互平行的倒V字形波纹板垂直排列组成,倒V字形波纹板的开口端向下。消泡板组件半浸于降液管泡沫层中,越堰的泡沫液与波纹板碰撞,以及波动的泡沫层不停地与波纹板摩擦,都加速泡沫的破裂,促进降液管内气液分离,降低了泡沫层高度。开口端向下的倒V字形波纹板还对降液管内液体产生向下的作用力,降低了降液管清液层高度。试验结果表明,对易起泡物系,降液管机械消泡板组件能降低泡沫层高度13.1%—36.2%,降低清液层高度10.5%—32.5%。对不易起泡物系,消泡板组件能降低泡沫层高度7.1%—33.2%,降低清液层高度5.1%—24.6%。因此,该消泡板组件可以起到降低降液管液层高度和延缓降液管液泛的作用,具有良好的消泡效果。     

液相黏度对筛板塔流体力学性能影响的研究

以空气-水、空气-甘油水溶液为物系,实验研究了黏度对筛板塔流体力学性能的影响.根据板压降、泡沫层高度、泡沫层平均气含率、雾沫夹带随气体流量变化的趋势,得出如下结论在相同的气速下,随着黏度增加,塔板压降降低,泡沫层高度降低;距测试筛板同一高度的雾沫夹带量随气量的增大而增加,随黏度增大而降低;雾沫分离空间相同时,雾沫夹带量随黏度增加而增大.根据实验数据还得出了不同气速下泡沫层平均气含率与气体空塔动能因子F的实验数据关联式.     

复合型塔板对易起泡物系的机械消泡研究

在 2 0 0mm× 70mm的有机玻璃塔中进行试验 ,以质量分数为 5 %为碳酸钾水溶液作为易起泡物系 ,测量了普通筛板和 4种复合型塔板的泡沫层高度 ,并用毛细管光电测量仪测量了气泡索太尔直径和气泡直径分布。试验结果表明 :复合型塔板能够机械消泡 ,其中填料放置于塔板一定高度处的复合型塔板消泡效果较好 ;并且 ,复合型塔板能够细化气泡 ,从而提高板效率     

易起泡物系消泡构件的研究

以空气-5%碳酸钾水溶液为实验物系，与空气-水物系作对照，测试了3种不同构件在筛板塔中的消泡功能。采用测量4次取平均的办法得到泡沫层高度，并结合毛细管光束检测技术测得气泡平均直径和气泡大小分布，通过对比分析，最值得推荐的消泡构件是距离塔板一定高度设置板波填料。     

浮阀塔板传质效率与双相流接触状态的关联

浮阀塔板上主要有喷溅、混合泡沫和完全泡沫三种汽液接触状态,塔板上汽液接触状态、雾沫夹带率和清液层高度三者有良好的对应关系。本文得出了状态转变点的规律,推导和提出了预测三种接触状态下液相传质效率和雾沫夹带率的方法,初步考核结果颇为满意。     

新型立体传质塔板及其流体力学性能

新型立体传质塔板（CTST）结构新颖, 充分利用塔板空间进行传质,具有通量大、效率高、压降低、抗堵性能强、消泡性能好等优点.在工业规模的实验塔上对立体传质塔板的塔板压降、帽罩底隙处罩内外压强、帽罩内部气相速度分布规律、雾沫夹带量、气体对液体的提升能力、塔板空间持液量等几个方面的流体力学性能进行了研究.结果表明,立体传质塔板克服了穿过塔板液层的阻力,板压降较低;塔板上帽罩底部的进液口处,罩内压强低于罩外,利于吸液;罩内气相速度分布比较合理;气液两相负荷均可较大幅度提高,而且雾沫夹带量非常低;气体对液体的提升性能以及塔板空间的持液性能都比较理想.     

新型固定阀塔板的流体力学和传质性能研究

提供了一种阀盖两侧具有向下弯曲折边的新型固定阀。在内径为500mm的有机玻璃塔内,以空气水为物系,研究了其流体力学性能;在内径为300mm的不锈钢塔内,以乙醇水为物系,常压全回流情况下,研究了其传质性能。研究结果表明:新型固定阀塔板的板压降略高于筛孔塔板,比F1 浮阀塔板小得多,雾沫夹带量小,雾沫夹带液泛点阀(筛)孔动能因子均比筛孔塔板、F1 浮阀塔板大,漏液量较小,漏液点阀(筛)孔动能因子比筛孔塔板低,比F1 浮阀塔板高,传质效率与F1 浮阀塔板相当。     

混合箱塔板流体力学性能实验研究

研究开发了一种大通量高效率的混合箱塔板 ,它的非传质区仅占塔截面积的 5 %左右 ,在塔板上设计了用于提高气液传质效率的混合箱结构。在冷模试验塔内对混合箱塔板的压降、漏液、雾沫夹带以及降液管清液层高度等流体力学性能进行了试验 ,试验表明该塔板的漏液和雾沫夹带都比传统筛板有所减少 ,且通量大幅度提高     

新型导向桥阀塔板的雾沫夹带和塔板压降

在φ1000mm的圆塔内,采用空气–水系统对新型导向桥阀塔板的流体力学性能进行了测试,考察了液流强度、出口堰高等因素对雾沫夹带和塔板压降的影响,并且与标准的F1型浮阀进行了对比实验。结果表明:新型导向桥阀塔板上气体分散均匀,泡沫层高度稳定,气液接触充分,在相同条件下压降比F1浮阀低10%～30%。具有较好的流体力学性能。     

主动旋转阀的流体力学性能研究

提出一种能够主动旋转的鼓泡元件,并在内径为300 mm×400 mm的矩形有机玻璃塔内,以空气-水为物系,研究了该阀体主动旋转对塔板压降、雾沫夹带的影响;用自制的电导探头测量了一定清液层高度下塔板的局部气含率,以研究阀体旋转对塔板局部气含率分布的影响。结果表明,阀主动旋转的干板压降与不旋转基本相同;阀主动旋转的湿板压降比不旋转时低,雾沫夹带比不旋转时大;阀主动旋转的局部气含率分布较不旋转时均匀,阀主动旋转时的气体对冲现象明显减少,塔壁附近的气液接触状况得到有效改善。     

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。