氨基磺酸盐镀镍的沉积速率与电流效率的研究

采用测厚法和恒电流沉积法,分别研究了镀液温度、阴极电流密度和添加剂对氨基磺酸盐镀镍的沉积速率与电流效率的影响。结果显示:在镀液中不含任何添加剂的前提下,镀镍的沉积速率和电流效率均随镀液温度的升高及阴极电流密度的增大明显提高,最高分别达到0.027 3μm/s和73.4%;而在电镀工艺参数相同的条件下,向镀液中加入适量的添加剂,镀镍的沉积速率和电流效率均略有提高。     

快速光亮化学镀镍工艺

弱酸性化学镀镍溶液体系采用复合配位剂以及一种添加剂,在80～90℃范围内可获得光亮镍磷合金镀层,沉积速率可达20μm/h.研究了温度、pH值及镀液成份对化学镀镍层沉积速率的影响,并讨论了镀液的稳定性及添加剂的作用.     

焦磷酸盐铜-锡合金镀液性能的研究

以焦磷酸铜和锡酸钠为主盐,焦磷酸盐为配位剂,加入一种自制的铜-锡合金添加剂组成焦磷酸盐镀液,通过赫尔槽实验优选出最佳镀液配方和工艺条件,并对镀液的分散能力、深镀能力、阴极电流效率和沉积速率等性能进行测试。结果表明:镀液的分散能力为98.05%,深镀能力为100%,平均电流效率为86.65%,平均沉积速率为59.2μm/h。加入添加剂后明显改善了镀液的极化性能,提高了铜离子及锡离子的析出电位,得到均匀致密、结晶细致、光亮整平的铜-锡合金镀层。     

陶瓷基上化学镀铜

为提高化学镀铜液的稳定性,在化学镀铜液中加入亚铁氰化钾和a,a′-联吡啶作为添加剂,研究了温度与陶瓷基体上化学镀铜沉积速度的关系,计算出铜沉积的活化能。当镀液中含有亚铁氰化钾或a,a′-联吡啶时,铜沉积活化能提高,铜沉积速率降低,镀铜层外观及镀液稳定性均得到改善。此外,镀液中同时含有亚铁氰化钾和a,a′-联吡啶时,镀液、镀层性能得到进一步提高。     

添加剂对无氰镀镉工艺性能的影响

本文采用电沉积方法制备了镉镀层,采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、盐雾试验箱、接触角测量仪测试了镀液添加剂对镀层结构、耐蚀性及接触角的影响,并利用赫尔槽、库仑计测试了镀液的分散能力、电流效率及沉积速率.结果表明:镀液加入维生素B衍生物后,所得镀层晶粒尺寸为44.8 nm,结晶细致均匀,耐蚀性良好.该镀液的分散能力为84％,电流密度为1 A/dm2时的电流效率为64.7％,沉积速率约为0.425μm/min.     

化学镀Ni—W—P合金工艺研究

研究镀液组成及工艺参数对镀层成分和沉积速率以及合金镀层表面形貌、结构、成分及硬度的影响。结果表明,添加剂的加入能显著地抑制镀液的自发分解。Ni-W-P 合金具有优异的耐蚀性。     

电沉积制备铁-镍因瓦合金的工艺研究

采用硫酸盐镀液体系,在紫铜箔上电沉积制备了Fe-Ni合金镀层,研究了镀液成分(如镀液中添加剂含量.Ni2+/Fe2+浓度比)及主要的沉积工艺参数(包括阴极电流密度、温度和搅拌速率)对镀层表面质量、成分及组织的影响.镀液成分及最佳工艺参数为:0.3 mol/L NiSO4·6H2O,0.08 mol/L FeSO4·7H2O,2g/L糖精,0.35 g/L 1,4-丁炔二醇,电流密度3.7 A/dm2,施镀温度40℃,搅拌速率200 r/min.     

响应曲面法优化氯化物体系三价铬电沉积工艺

[目的]三价铬电沉积过程中伴随的剧烈析氢反应导致局部pH升高,是镀速急剧下降、镀层难以增厚及镀层性能恶化的主要原因。[方法]采用甲酸钠、草酸钠和尿素为氯化物体系三价铬电镀的配位剂,以在150 mA/cm²电流密度下电沉积10 min的沉积速率为响应因子,采用响应曲面法优化了镀液配方,建立了氯化物体系三价铬电沉积速率的多项式模型方程。通过单因素实验研究了添加剂、pH、温度、电流密度和沉积时间对沉积速率、镀液深镀能力和镀层耐蚀性的影响。[结果]三价铬电沉积的最佳配方和工艺条件为：三氯化铬0.6 mol/L,甲酸钠0.8 mol/L,草酸钠0.2 mol/L,尿素0.3 mol/L,p H 1.8,温度30℃,电流密度150 mA/cm²,时间30 min。在该条件下所得Cr镀层为非晶态结构,厚度在12μm以上,耐蚀性良好。[结论]选用合适的配位剂抑制电沉积过程中铬的羟桥化反应,是维持较高镀速和改善镀层性能的有效手段。     

稀土La对电沉积Ni-P合金镀层工艺的影响

研究了添加稀土La电沉积电磁屏蔽N i-P合金镀层的工艺。在正交试验的基础上分析了镀液组成及电流密度对沉积速率的影响,综合考察了镀层表面质量及镀层与基体的结合力。结果表明:在镀液中加入微量稀土La,金属离子的沉积速率,镀层与基体的结合力,镀液的分散能力,镀层的表面质量都有不同程度的提高,并由此得出工艺的最佳镀液组成和操作条件。     

电沉积制备Ni-W-Al2O3纳米复合镀层的初步研究

初步研究了电沉积Ni-W-Al2O3纳米复合镀层的制备工艺。考察了纳米粒子的分散方式、纳米粒子在镀液中的浓度以及镀液温度对沉积速度、复合量及镀层形貌的影响。结果表明:纳米粒子加入镀液前超声分散1h、施镀时对镀液采用超声搅拌效果最佳;纳米粒子在镀液中的含量为15g/L时沉积速率最大,为2.88g/(dm2·h);镀液温度为75~80°C时沉积速率较大且较稳定,且当施镀温度为75°C时镀层表面均匀有光泽,呈银白色。     

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。