塑料土工格栅的特性及其在土木工程中的应用

介绍以聚烯烃为主要原料制备塑料土工格栅的生产工艺，塑料土工格栅具有拉伸强度高，伸长率低、与土石结合效果好，耐久性强、施工简便等特点，是一种优良的土工材料，在土木工程中得到广泛应用。     

塑料土工格栅蠕变性能测试方法探讨

研究了塑料土工格栅蠕变性能与拉伸强度之间的关系,并证明了塑料土工格栅蠕变行为符合时温等效原理,应用时温等效原理可在较高温度下试验得到较低温度下更长期的设计强度。     

双向拉伸土工格栅生产工艺及装备

塑料土工格栅是新型的土工合成材料,分为单向拉伸和双向拉伸土工格栅,用作土木工程的加固,加筋材料,适用于公路,铁路,水利工程的软基处理和路面,路堤,河堤的加固,滑坡,塌方的修复及有治理水土流失,而我国尚无一条合格的双向拉伸土栅生产线,经多年研究的试验,结合国外先进的生产技术,本文简要介绍其生产工艺及主要装备。     

土工格栅拉伸速率试验分析

通过对土工格栅(塑料格栅和玻纤格栅)在不同速率下进行拉伸试验,得出拉力—变形曲线及2%,5%应变和峰值拉伸强度、最大断裂力时的延伸率等数据。经过对数据分析和曲线拟合,得出格栅受拉伸速率影响的规律,并最终选定合适的室内拉伸试验速率。结果表明,塑料格栅和玻纤格栅,纵、横向的断裂拉力随着拉伸速率的增加而增大,延伸率随着拉伸速率的增加而减小。塑料格栅和玻纤格栅,纵、横向同等规格时,纵向拉伸强度总体大于横向拉伸强度。     

大连研发单双向拉伸塑料土工格栅生产线

大连塑料研究所研制开发的单、双向拉伸塑料土工格栅生产线及技术,近日通过鉴定。 专家认为,该生产线设计合理,土工格栅纵向拉伸的双极多点拉伸技术为国内外自创,横向拉伸技术采用了结构合理的夹具及先进可靠的调速手段与加温方式,生产线传动平     

大连研发单双向拉伸塑料土工格栅生产线

大连塑料研究所研制开发的单、双向拉伸塑料土工格栅生产线及技术，近日通过鉴定。专家认为，该生产线设计合理，土工格栅纵向拉伸的双极多点拉伸技术为国内外首创，横向拉伸技术采用了结构合理的夹具及先进可靠的调速手段与加温方式，生产线传动平稳，温度均匀。采用本技术生产的土工格栅，具有强度高、质量轻、价格低廉、性能可靠的特点。该产品经检测，各项性能指标达到国外同类产品水平，其中2%、5%伸长率下的单位宽度拉力均超过国际同类产品水平。本刊摘编自《中国化工报》，2002-9-2大连研发单双向拉伸塑料土工格栅生产线     

塑料土工格栅的长期性能与质量保证

利用时温叠加原理和最小偏差原理,对同一系列多种规格的高密度聚乙烯（HDPE）单向拉伸土工格栅在不同温度下的蠕变性能进行测试,并结合数学方法在短期内预测其长期性能。该方法置信度高,可广泛应用于塑料土工格栅质量保证及工程设计中,大大减小了工程设计的误差,确保了塑料土工格栅使用的安全性。     

关于塑料土工格栅冲孔模具的相关研究

冲孔模具在塑料土工格栅产品生产中占据着十分重要的地位,并且冲孔模具参数也会直接影响到生产产品的拉伸强度、单位面积质量等,加强塑料土工格栅冲孔模具研究就非常有必要。本文联系塑料土工格栅的基本概述,对塑料土工格栅生产工艺、冲孔装置、模具参数等进行细致的分析,并围绕冲孔模具工作失效问题,尝试从优化模具参数、合理模具结构、选用合适钢材、加强模具维护等方面入手,提出几点有效应对策略,以供参考。     

全国土工聚合物排水带应用技术研讨会九月底在宁召开

<正> 随着化纤工业、塑料工业的飞跃发展,高分子聚合物在土工工程中应用越来越广泛,早在六十年代,工业发达国家已广泛运用土工聚合物排水带、土工布、塑料盲沟、塑料格栅、塑料土筋等。七十年代末,已有大批国外厂商来我国推销其土工制材产品。     

塑料土工格栅的现场破坏实验

论述塑料土工格栅现场破坏实验的必要性,以青岛颐中格栅股份有限公司生产的EGR系列塑料土工格栅为对象,进行了现场破坏实验。实验测得不同型号的塑料土工格栅在不同填料中的最高损伤因子,得到了适用于工程设计的损伤因子,并发现填料的级配是影响塑料土工格栅损伤因子的主要因素之一。     

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。