吸波材料研究进展

吸波材料的研究是隐身技术发展的关键,是当代隐身技术发展的重点方向之一,而吸波剂质量的好坏决定了吸波材料的性能。介绍了吸波材料的工作原理,主要从无机吸波材料和有机吸波材料方面进行概述,重点阐述了铁系、碳系和陶瓷类、导电高分子类等吸波剂的性能及研究状况,并指出今后的发展方向。     

新型吸波材料的应用及研究

分析了不同情况下吸波材料的吸波机理和吸波特性。阐述了近年来应用研究较多的新型无机吸波剂如:碳系、铁系以及手性吸收剂的结构特性以及研究现状。同时介绍了聚合物与无机吸波剂复合,制备新型吸波材料的研究进展。此外,还提出了现有微波吸收材料研究中存在的不足及进一步的研究方向。     

无机吸波材料研究进展

本文论述了无机吸波材料种类、吸波原理和研究进展.重点对铁氧体、金属微粉、碳纳米管、碳纤维、纳米氧化物和陶瓷等吸波材料的研究进展进行了分析和讨论,并指出了吸波材料今后的研究重点和发展方向.     

陶瓷吸波材料的研究进展

简述了在当今世界能提高各类武器在战争中的生存能力、防卫能力和攻击能力的隐身技术,对其在现代高技术武器装备中的重要作用进行了肯定。对隐身技术中占重要地位的电磁波吸收材料的种类、吸波原理及吸波方式做了进一步阐述。重点讨论了陶瓷吸波材料的吸波原理、组成结构和方式,并着重介绍了几种最近几年陶瓷吸波材料的最新研究成果,列举了它们的吸波性能参数。最后,对陶瓷吸波材料发展方向进行了展望。     

吸波材料的研究进展

吸渡材料的研究是隐身技术发展的关键,吸波剂的好坏对于吸波材料的性能有很大的影响。本文在对吸波材料以及其吸波原理进行介绍的基础上,大体阐述了有关吸波材料的研究进展,通过对几种常用的微波吸波剂的介绍,提出了未来吸波材料的发展将向着”薄、轻、宽、强”和耐腐蚀性等方面进行研究。     

柔性橡胶吸波材料的研究进展

概述柔性橡胶吸波材料吸波基本原理,重点介绍铁氧体系橡胶吸波材料、金属铁微粉系橡胶吸波材料、碳系橡胶吸波材料以及多层橡胶吸波材料的研究状况。目前橡胶吸波材料的探索大多局限于实验室研究,橡胶吸波材料还未能成熟地进行工业化生产和应用,需要进一步探讨高温、低温、振动冲击等环境因素以及硫化体系和混炼工艺对橡胶吸波材料吸波性能的影响,开发能够吸收特定波长的橡胶吸波材料。     

生物质衍生碳基复合吸波材料的研究进展

为了满足军事国防领域对隐身技术的需求,解决5G时代广泛的电磁污染问题,各类型的碳基吸波材料异军突起。生物质衍生碳基材料相比传统碳基吸波材料,不仅提高了吸波性能,还具有轻质、低成本和可持续的优势。简要叙述了生物质碳材料的合成方法,系统地介绍了可食用和非食用2种生物质衍生材料在碳基复合吸波材料制备中的应用,综述了近几年来生物质衍生碳基复合材料在吸波领域的最新研究进展。重点分析了不同生物质衍生碳基复合材料的微观结构、微波吸收性能的差异,并概述了不同生物质衍生碳基复合材料吸波机理,最后讨论了具有高效微波吸收性能的生物质碳基复合吸波材料所面临的挑战,展望了其未来发展的方向。为从事生物质衍生吸波材料的科研工作者提供了较为全面的理论和应用知识背景,并有望进一步推进生物质衍生碳基复合吸波材料的发展及应用。     

吸波弹性体材料的研究进展

以弹性体为基体的吸波材料,因其具有良好的柔性和可设计性,近年来受到广泛关注.重点介绍了碳系吸波弹性体、铁氧体系吸波弹性体、磁性金属系吸波弹性体和碳基/磁性复合吸波弹性体的制备方法和吸波性能,并展望了吸波弹性体材料的发展方向.     

吸波材料的研究进展

吸波材料的研究是隐身技术发展的关键,是当代隐身技术发展的重点方向之一,对于提高军事目标和武器平台的生存能力和战斗能力至关重要.文章阐述了吸波材料的工作原理,综述了吸波材料最新研究进展,并指出了其未来的发展方向.     

高熵陶瓷吸波材料研究进展

吸波材料是指能吸收或者大幅减弱其表面接收到的电磁波能量，从而减少电磁波干扰的一类材料。近年来对吸波材料的探索中出现各种高熵陶瓷吸波材料，通过热力学的高熵效应、结构的晶格畸变效应、动力学的迟滞扩散效应以及组元的协同增效作用，获得高熵陶瓷材料的吸波性能优于单组元的吸波性能。基于近年来的研究成果，本文归纳总结了不同种类高熵吸波陶瓷的组元设计、制备与吸波性能关系的相关研究结果，分析了高熵效应对吸波性能的影响规律，最后，总结了目前研究工作中存在的关键科学难题与挑战，并展望了高熵吸波陶瓷的未来前景和发展方向。     

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。