相变储能材料的研究及应用新进展

综述了近年来相变储能材料的研究和应用新进展.介绍了相变材料的种类及各类相变材料特点,并对各类相变材料的性能、储能机理和优缺点进行了讨论;探讨了相变材料在太阳能利用、建筑节能等领域的应用;展望了未来相变材料的发展方向和应用前景.     

相变储热材料研究进展

对储热特别是相变储热材料的研究进展进行了综述.根据不同相变温度对相变储热材料进行分类,重点介绍了目前广泛应用的相变储热材料的重要性能、制备方法、应用及存在的问题,并对相变储热材料的下一步研究进行了展望,提出将相变材料的研究与相变储热换热器和热管理理念相结合是发展高效储能系统的主流发展方向.     

相变材料在动力电池中的应用研究进展

从相变材料的类型和特点分析了适用于锂电池热管理的材料,阐述了相变材料的选型和制备的研究现状.获取高导热系数、高潜热的复合材料将是相变材料制备研究的主要方向.从换热方式的角度出发,综述了被动式、主动式基于相变材料的热管理系统研究进展,并展望了今后的发展方向.     

聚合物基相变储能材料的研究与发展

相变储能材料由于其独特的功能作用以及广阔的发展前景引起了各国科研单位的极大关注,并形成了世界范围内的研究热潮.阐述了当前相变材料发展现状,并详细介绍了目前各种相变储能材料的制备工艺,并对各种制备方法的优点和缺点做了简单分析.此外还总结了当前研究中需要解决的实际问题,并对未来的研究方向提出了自己的看法.     

相变储能材料在温室大棚中应用研究进展

采用相变储热材料(PCMs)潜热储蓄技术是最有效热能贮存方式之一,将其应用于温室节能有重要意义.本文综述了低温相变储热材料在温室大棚中的应用条件及类型,国内外低温相变储热材料的研究现状.分析了温室储热材料的性能与存在问题,展望了低温相变储能材料的发展方向和应用前景.     

相变材料及其在建筑节能中的应用

建筑用能是能源消耗的大户,随着建筑行业的迅速发展,节能越来越受到重视,而相变材料在建筑节能中的运用尤为重要。本文对相变材料的分类、选择、使用方式及在建筑节能中的应用等进行了简单地综述,为相变材料在建筑节能工程中应用提供借鉴。     

复合相变材料在混凝土中的应用研究进展

复合相变材料具有较大的相变潜热,可以改善相变材料分散性差、易渗漏的缺点,选用合适的复合相变材料能有效降低大体积混凝土水化热和混凝土建筑的能耗.介绍了复合相变材料的制备方法,综述了其在大体积混凝土和混凝土建筑节能中的应用研究进展,并对当前研究中存在的问题和未来发展前景进行了分析和探讨.     

聚乙二醇/二氧化硅复合定形相变储能材料的制备与研究

为拓宽相变储能材料在实际工程中的应用范围,以聚乙二醇(PEG)为相变储能材料,二氧化硅(SiO2)为载体基质,采用溶胶-凝胶法制备了一种有机-无机复合定形相变材料.通过DSC、TGA、SEM和相变循环试验对复合定形相变材料的结构与性能进行测试,试验结果表明:聚乙二醇的最佳质量分数为70％,相变温度为49.73℃,相变焓...     

相变材料在水泥基材料中的应用

相变储能已成为水泥基材料领域的研究热点.本文总结了水泥基材料领域常用相变材料的类型与特点,阐述了相变材料在水泥基材料中的3种植入方式:浸渍吸附法、定型封装法、胶囊封装法.讨论了相变材料对水泥基材料工作性能、力学性能及水泥水化历程的影响规律,介绍了相变材料在水泥基材料中的应用情况,探讨了相变材料研究存在的问题与发展趋势.     

基于VIKOR法的相变材料性能评价研究

随着相变材料在材料科学领域的不断发展,其评价和选择逐渐受到人们的关注,相变材料评价指标通常包括相变焓、比热、导热率、密度、过冷度和价格等各方面,但是其性能评价不够科学和系统.本文利用VIKOR法构建了法不同层次的指标体系,建立了相变材料性能评价模型,以AHP法确定指标体系的权重,通过评价模型对各种相变材料的综合性能进行排序,研究表明,基于VIKOR法的评价模型的评价结果与实际研究相吻合,说明VIKOR法具有较强的实际性和理论性.     

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。