(Ni-P)-Si_3N_4复合镀层硬度及耐磨性研究

利用化学镀方法获得了(Ni-P)-Si3N4复合镀层,并研究了Si3N4颗粒含量、pH及热处理条件对镀层硬度及耐磨性的影响。采用扫描电子显微镜观察,镀层表面平整,Si3N4微粒均匀复合在镀层中。机械性能测试表明,镀层的硬度与耐磨性能随着镀液中次磷酸钠质量浓度的增加呈现出先提高后降低的趋势。当镀液中Si3N4质量浓度为10g/L时,镀层硬度及耐磨性最好,热处理后的镀层硬度高达1088HV。     

复合刷镀纳米Ni-ZrO2高温耐磨性的研究

复合刷镀纳米Ｎｉ－ＺｒＯ２镀层具有优良的高温耐磨性,常用于设备在高温下磨损后的修复处理。提出了一种纳米Ｎｉ－ＺｒＯ２复合刷镀工艺,研究了镀液中纳米ＺｒＯ２含量度怪中的纳米ＺｒＯ２粒子复合量的影响,时效热处理与镀层硬度的关系。镀层中的ＺｒＯ２粒子复合量随镀液中ＺｒＯ２含量的增大而增大,时效热处理能明显提高镀层的硬度,经４００℃时效热自理后,硬度达最大,纳米Ｎｉ－ＺｒＯ２复合镀层的高温耐磨性是基材（４     

化学复合镀Ni-P-Cr_2O_3工艺及镀层性能的研究

研究了Ni P Cr2 O3 化学复合镀工艺 ,以及热处理对镀层硬度、耐磨性的影响 ,并与Ni P镀层作了对比。结果表明 ,通过制定合理的镀制工艺和控制镀液中Cr2 O3 固体颗粒的添加量 ,可提高镀速 ,获得Cr2 O3 颗粒含量适宜的复合镀层。另外 ,采用正确的热处理工艺 ,可使镀层的硬度、耐磨性显著改善     

化学复合镀中金刚石颗粒的分散对复合镀层性能的影响

通过数值仿真,研究了镀槽结构与搅拌速率对镀液流场和镀液中金刚石颗粒分布特性的影响,并制备了镍–磷–金刚石复合镀层,研究了镀槽结构与搅拌速率对镀层中金刚石含量、粒径分布以及镀层显微硬度和耐磨性的影响。结果表明,镀槽中添加挡板和提高搅拌速率,可以明显改善镀液流场的均匀性,有利于金刚石颗粒在镀液与镀层中的分散与均匀分布,显著提高复合镀层的显微硬度与耐磨性;当镀槽中有挡板、搅拌速率为600 r/min时,所制备的微米金刚石–镍–磷复合镀层经400°C热处理1 h后,显微硬度高达1 442 HV,镀层几乎无磨损。     

电沉积RE-Ni-W-P-SiC复合镀层的硬度与耐磨性研究

研究了RE-Ni-W-P-SiC复合镀层的硬度与耐磨性。结果表明，随着加热温度的提高，复合镀层的硬度和耐磨性增加，在400℃时达峰值，温度继续升高，复合镀层硬度和耐磨性呈下降趋势，随着复合镀层中磷含量的增加，其耐磨性改善，在400℃热处理条件下，随着热处理时间的延长，复合镀层的硬度和耐磨性增加，当热处理时间达到3h时，复合镀层硬度和耐磨性达到最佳值，随着镀液中SiC和钨酸钠浓度的增加，复合镀层的硬度和耐磨性均增强。     

(Ni-P)-纳米Si3N4微粒复合刷镀工艺研究

论述了（Ni-P)-纳米Si3N4微粒复合刷镀工艺,设备及（Ni-P)-纳米Si3N4微粒复合刷镀液的组成和配制方法;研究了纳米Si3N4微粒在刷镀液中的含量,刷镀工作电压和刷镀温度对（Ni-P)-纳米Si3N4微粒复合刷镀层的影响;研究了在不同的热处理温度下复合刷镀层的硬度和耐磨性。     

聚乙烯亚胺对Si3N4纳米微粒复合刷镀的影响

研究了聚乙烯亚胺对刷镀(Ni-P)-Si3N4纳米微粒复合镀液中Si3N4纳米微粒的分散性、刷镀层性能及结构的影响,并确定了聚乙烯亚胺在复合刷镀液中的最佳含量。结果表明,聚乙烯亚胺能有效阻止复合刷镀液中颗粒的絮凝、团聚,其用量对复合刷镀层中Si3N4含量、刷镀层硬度及耐磨性能有显著的影响。当其质量浓度为0.8 g/L时,获得了微粒均匀分散,稳定悬浮的复合刷镀液,复合刷镀层微观表面结构致密,微粒分布均匀,磨损量最小,显微硬度最大。     

(Ni-P)-纳米Si3N4复合刷镀层结构及性能研究

1引言 复合刷镀是指在镀液中纳米级的不溶性的固体形成纳米复合刷镀层.用具有很好悬浮性能的纳米Si3N4固体微粒作为复合刷镀液的第二相粒子,通过搅拌使其悬浮在镀液中,用电刷镀的方法使Ni-P合金与纳米Si3N4微粒共沉积于基体表面.它具有沉积速度快、镀层硬度高和耐磨性好等优异的性能.     

化学复合镀(Ni-W-P)-Si3N4工艺研究

采用化学复合镀方法,制备了(Ni—W—P)—Si3N4复合镀层;研究了镀液组成及工艺参数对镀层成分和沉积速率的影响;采用X—射线衍射分析了复合镀层表面相结构,并对复合镀层的耐蚀性及耐磨性进行了测试分析。试验结果表明：Si3N4纳米颗粒的加入影响了镀层的沉积速率,提高了沉积层的耐磨性;(Ni—W—P)—Si3N4复合沉积层仍具有与Ni—W—P沉积层相近的优异性能。     

Ni-Si3N4纳米复合镀层研究

将Si3N4纳米粒子加入电镀镍的基础镀液中,在碳钢上制备了Ni–Si3N4复合镀层。扫描电镜观察表明,复合镀层的表面晶粒细小致密。能谱分析结果表明,镀层表面以Ni元素为主,且含有少量的Si和N。随着镀液中纳米Si3N4粒子含量的增加,镀层的显微硬度升高。热震法和划痕法实验表明,镀层与基体结合良好。     

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。