浅析圆中空涤纶中空度的控制

分析了喷丝孔孔形、纺丝温度、冷却成形条件、拉伸倍数对圆中空涤纶中空度的影响,并结合中空纤维其它质量指标,采取熔体温度２８０℃,风速０．５５ｍ／ｓ,风温２４℃,泵供量２８８ｇ／ｍｉｎ,拉伸倍数４．３５的工艺条件,可生产出中空度约为２２％的圆中空涤纶。     

热固性塑料的中空成型

传统的中空吹塑成型技术只能适用于热塑性塑料？现在．利用熔芯中空成型技术便可以将热固性塑料制成性能优良的中空制品。[编者按]     

聚丙烯腈中空纤维膜的研究

本文对聚丙烯腈中空纤维膜的原料组成，中空纤维的纺丝工艺与膜性能的关系，以及纺制不同结构中空纤维膜的纺丝工艺和方法进行了综述，提出了纺制耐热性好的聚丙烯腈中空纤维３膜可能的方法和意义。     

中空纤维渗透汽化膜分离研究现状与展望

本文综述了中空纤维渗透汽化膜分离的研究进展,包括中空纤维支撑膜的制备、复合膜的制备方法、中空纤维渗透汽化膜的工业应用和中空纤维渗透汽化膜传质特性等几个方面,对这个方面所存在的问题以及今后发展方向进行了展望.     

中空制品成型技术

随着中空塑料制品复杂程度的提高以及应用范围的不断扩大，用于中空成型的工艺技术也越来越多。     

中空冷却塔热力计算模型初探

中空冷却塔在降温效果、综合能耗和设备投资等方面均优于传统的填料冷却塔,已经在工业中得到了广泛的应用.但是至今未有文献对中空冷却塔的热力计算方法进行系统讨论.作者以Merkel焓差法公式为基础建立了中空冷却塔一维传热传质模型,推导出中空冷却塔的基本热力计算方程式,为中空冷却塔的实际应用提供了理论基础.     

中空纤维膜用喷丝板

聚砜中空纤维超滤膜以其截面形状(圆中空)而论,属于异形纤维,就其性能而言,属于特种纤维。为使聚砜中空纤维在一定的压力下具有良好的渗透和渗透选择性能,要求具有理想的微观结构(纤维表面层有孔径为30—1000(?)的微孔)和截面形状(适当的中空度,圆整的内外孔)。膜用中空纤维不同于一般服装用的中空纤维,前者对纤维截面形状要求十分严格,因为     

中空纤维膜的现状与研究进展

综述了中空纤维膜的现状和研究进展,包括中空纤维膜的发展历史、中空纤维膜的制备方法、中空纤维膜的工业应用等几个方面,提出了中空纤维膜应用存在的问题,对这个方面所存在的问题和今后发展方向进行了展望,并提出建议。     

聚合物模板法制备中空材料研究进展

中空结构材料具有低密度、高比表面积、可以容纳客体分子等特点，被广泛应用于生物医药、环境保护、保温涂层等领域。在各种制备中空材料的方法中，模板法因具有简单、高效、再现性好等诸多优点而被广泛采用。本文重点阐述了以聚苯乙烯，三聚氰胺甲醛树脂和其他聚合物为模板来制备中空材料的方法以及形成机理。     

高吸汗透气PBT/PET共混中空和异形中空微孔纤维

本文探讨了PBT/PET共混中空和异形中空纤维及其微孔纤维的力学性质、输水性和保水性。指出:聚酯异形中空纤维和异形中空微孔纤维具有优良的输水性和保水性,力学强度综合服用纤维要求,该纤维具有良好的变形加工和机织能力,适宜做聚酯系列仿丝绸、仿毛及针织产品,能大大提高其服用舒适性。     

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。