船用柴油机活塞杆表面微粒增强镍基复合镀层的制备及其性能分析

采用电沉积方法,在船用柴油机活塞杆表面分别制备纳米微粒增强镍基复合镀层、亚微米微粒增强镍基复合镀层和微米微粒增强镍基复合镀层。分析了三者的显微形貌、晶相结构及磨痕形貌,并测定了硬度。结果表明:与亚微米微粒增强镍基复合镀层和微米微粒增强镍基复合镀层相比,纳米微粒增强镍基复合镀层的外观显得更加光亮,硬度接近5 800 MPa。     

镍基纳米复合镀层的研究进展

综述了镍基纳米复合镀层的研究现状。阐述了复合镀层的沉积机理、纳米微粒在复合镀层中的作用机理、纳米微粒在镍基镀液中的分散以及镍基纳米复合镀层的种类和性能。指出了纳米复合镀技术研究中存在的问题和发展方向。     

纳米SiC微粒增强镍基复合材料的研究进展

探讨了制备纳米SiC微粒增强镍基复合材料的工艺条件,介绍了纳米SiC微粒增强镍基复合材料的应用方向,并讨论了基于超临界二氧化碳流体制备镀层的方法。     

镍基纳米复合镀层的研究现状

镍基纳米复合镀层中由于复合纳米颗粒的特性而被广泛应用。就国内外镍基纳米复合镀层的研究现状进行了分析,对镍基纳米复合镀层的沉积机理、镀层结构特点、影响纳米颗粒与镍金属电沉积的主要工艺因素、镀层性能及应用进行了阐述。当前具有更优良硬度、耐磨性、耐腐蚀性、减摩性、催化功能和抗高温氧化性的镍基纳米复合镀层是行业的研究热点。对镍基纳米复合镀层的研究还属于初步阶段,理论研究还需进一步深入。     

镍基SiC纳米微粒复合电镀研究

以镀层中SiC复合量为参考标准,通过正交试验,考察了SiC纳米微粒、电流密度、pH和空气流量四个因素对SiC复合量的影响,发现镀液中的SiC纳米微粒质量浓度对复合量影响最大。根据正交试验结果得出镍基SiC纳米微粒复合电镀的最佳工艺条件。在最佳工艺条件下,对Ni-SiC复合镀层表面形貌和能谱进行分析。     

工艺参数对Ni-SiC纳米复合镀层硬度的影响

为了提高结晶器铜板的使用寿命,采用电沉积的方法得到了Ni-SiC纳米复合镀层。采用单因素实验法对影响电镀层硬度的阴极电流密度、SiC纳米微粒添加量、pH及温度等进行了研究。结果表明,Ni基SiC纳米复合电镀工艺参数均对复合镀层的硬度有影响。对Ni-SiC纳米复合镀层的表面形貌进行了测试,确定最优工艺条件为8g/L SiC纳米微粒,Jκ为3A/dm2,pH为4.0,θ为30℃。纳米复合镀层的硬度与纯镍镀层相比有明显提高。     

镍/纳米二氧化硅纳米复合镀层耐腐蚀性能的研究

制备了纳米氧化硅镍复合镀层材料,并利用静态浸泡法对纯镍镀层和由镀液中不同微粒含量制备的复合镀层样品的耐蚀性能进行了研究,讨论镀液中纳米微粒含量对镀层抗蚀性能的影响。并用扫描电镜观察镀层的表面形貌。     

Ni-纳米SiO2复合镀层耐蚀性的初探

制备了纳米氧化硅—镍复合镀层材料，并利用静态浸泡法对纯镍镀层和由镀液中不同微粒含量制备的复合镀层耐蚀性能进行研究，讨论了镀液中纳米微粒含量对镀层抗蚀性的影响，并用扫描电镜观察镀层的表面形貌。     

复合电刷镀技术修复气缸套的应用研究

本文通过分析汽车气缸套磨损的规律、原因以及气缸套磨损后的可修复的工艺方法，采用含WC纳米微粒的镍基复合电刷镀层作为修复层或强化层，结果表明其耐磨损性能和耐腐蚀性能都高于未经电刷镀处理或单一镍基电刷镀层的气缸套。     

镍基氧化铝纳米微粒复合电镀的研究现状

以Al2O3纳米微粒为复合材料的复合电镀是一种取代镀硬铬的极有价值的复合表面技术。Al2O3微粒与镍金属共沉积可明显提高镀层的硬度、耐磨性与耐蚀性。主要阐述了Al2O3纳米微粒与金属镍共沉积的工艺条件对沉积速率和镀层性能的影响。并且指出Al2O3纳米微粒复合镀镍中关键问题是如何提高复合镀层中纳米微粒的含量及镀层形貌对镀层性能的影响,以寻找控制镀层表面形貌的条件。     

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。