纳米SiO_2微粒的质量浓度对Ni-Zn-P/纳米SiO_2复合镀层组织和性能的影响

采用碱式化学镀方法在Q235钢表面制备了Ni-Zn-P合金镀层和Ni-Zn-P/纳米SiO_2复合镀层。研究了硫酸锌、硫酸铵及柠檬酸钠的质量浓度对Ni-Zn-P合金镀层组织的影响,并研究了纳米SiO_2微粒的质量浓度对Ni-Zn-P/纳米SiO_2复合镀层性能的影响。通过单因素试验确定的化学镀Ni-Zn-P合金镀层的最优工艺条件为:硫酸锌0.5g/L,硫酸铵40g/L,柠檬酸钠50g/L,硫酸镍27g/L,次磷酸钠16g/L,pH值9.0,温度85℃。当纳米SiO_2微粒的质量浓度为1.0g/L时,NiZn-P/纳米SiO_2复合镀层表面光滑平整,组织均匀致密。随着纳米SiO_2微粒的质量浓度的增加,Ni-Zn-P/纳米SiO_2复合镀层的硬度逐渐提高。Ni-Zn-P/纳米SiO_2复合镀层比Ni-Zn-P合金镀层更耐Cl-和碱性溶液腐蚀,而且在纳米SiO_2微粒的质量浓度为1.0g/L时,Ni-Zn-P/纳米SiO_2复合镀层的腐蚀速率最低。     

汽车用碳锰钢化学镀Ni-Mo-P合金镀层性能的研究

在汽车用碳锰钢(16Mn钢)表面制备了化学镀Ni-Mo-P合金镀层,并研究了pH值对化学镀Ni-Mo-P合金镀层性能的影响。结果表明:升高pH值有利于增大化学镀Ni-Mo-P合金镀层的沉积速率及厚度。但当pH值大于10时,镀液容易发生水解。随着pH值的增大,化学镀Ni-Mo-P合金镀层中钼的质量分数逐渐提高,进一步提高了化学镀Ni-Mo-P合金镀层的显微硬度和耐蚀性。化学镀Ni-Mo-P合金镀层呈现出典型的颗粒结构,增大pH值有利于细化晶粒。当pH值为11时,化学镀Ni-Mo-P合金镀层具有最高的显微硬度和最佳的耐蚀性。     

机械结构钢表面三种化学镀层的性能比较

在40Cr钢表面分别制备了化学镀Ni-P合金镀层、化学镀Ni-Co-P合金镀层和化学镀Ni-P/SiC复合镀层。观察了三种化学镀层的形貌和微观结构,并测试了三种化学镀层的显微硬度、磨损量和摩擦因数。结果表明:三种化学镀层的表面质量整体较好,都呈胞状形貌;当衍射角2θ为45°左右时,三种化学镀层的XRD谱图中都出现了明显的漫散射峰,三种化学镀层都为非晶态结构;三种化学镀层中,化学镀Ni-Co-P合金镀层的显微硬度最高,耐磨性最好。     

燃机压气机导叶轴用钢化学镀Ni–P合金

在导叶轴用钢12Cr12Mo表面化学镀制备Ni-P合金镀层,研究了镀后热处理温度对Ni-P合金镀层组织结构、显微硬度和耐磨性的影响。结果表明,Ni-P合金镀层与基体紧密结合,无裂纹、孔隙等缺陷。在400℃下热处理1h后,Ni-P合金镀层由非晶态结构转变为以Ni₃P稳定相为主的晶体结构,显微硬度高达916 HV,耐磨性良好。     

化学镀Ni–P合金镀层热处理及磨损性能的研究

在20CrMnTi低碳钢上实施渗碳工艺,再化学镀Ni–P合金,研究了不同热处理温度对Ni–P合金镀层结构、显微硬度和结合力的影响,探索了不同载荷下Ni–P合金镀层的耐磨性,并与渗碳层进行了对比。结果表明,随着热处理温度的提高,Ni–P合金镀层由非晶态转变为晶态,并伴随着新相Ni3P的析出。镀层结合力随热处理温度的升高不断增强,而镀层显微硬度和耐磨性则先增大后减小,并在400°C时达到最大值。在本试验条件下,化学镀Ni–P合金镀层的耐磨性优于渗碳层。     

两种不同类型的化学镀层对汽车用铝材表面性能的影响

在汽车用铝材表面分别制备了化学镀Ni-P合金镀层和化学镀Ni-P-WC复合镀层。分析了两种不同类型的化学镀层的成分,并研究了两种不同类型的化学镀层对铝基体表面性能的影响。结果表明:化学镀Ni-P合金镀层中主要含有Ni、P两种元素,化学镀Ni-P-WC复合镀层中主要含有Ni、P、W、C四种元素,Ni的质量分数都在80%以上;两种不同类型的化学镀层都能显著提高铝基体的显微硬度和摩擦学性能;通过适当的热处理,能进一步提高两种不同类型的化学镀层的显微硬度,并降低磨损量。     

化学镀时间对Ni-Co-P合金镀层性能的影响

采用化学镀技术在铜基体上制备了Ni-Co-P合金镀层,研究了化学镀时间对镀层微观形貌、厚度、显微硬度和耐腐蚀性能的影响。结果表明:化学镀20～120 min时的镀层都呈胞状形貌,且都含有Ni、Co、P、C和O五种元素。随着化学镀时间延长,镀层微观形貌发生变化,Ni和P元素质量分数总体呈升高的趋势,Co元素质量分数总体呈降低的趋势,厚度呈现出先显著增加后缓慢增加的趋势,显微硬度在325～542 HV之间呈先增大后趋于稳定的趋势,耐腐蚀性能逐渐改善。化学镀120 min时的镀层表面较为平整致密,胞状物的尺寸明显减小,显微硬度达到542 HV,在氯盐溶液和弱碱性溶液中都表现出相对较好的抗腐蚀能力。     

钨对化学镀Ni-W-P合金镀层结构及性能的影响

通过不同的化学镀工艺配方,获得了4种不同钨含量的化学镀Ni-W-P三元合金镀层.研究了钨含量对镀层结构、硬度及在5%H2SO4溶液中耐蚀性的影响规律.研究发现,化学镀Ni-W-P三元合金镀层的结构受镀层中钨含量的影响较大,非晶态Ni-W-P三元合金镀层所需磷含量较非晶态Ni-P二元镀层所需磷含量要低,并且钨含量越高,所需磷含量越少;镀层硬度随镀层结构从非晶态→混晶态→纳米晶态转变而增加;镀层的耐蚀性随镀层中钨含量增加而变好,且非晶态镀层较混晶态和纳米晶态镀层更易形成钝化区.     

前处理工艺对铝基Ni-P化学镀层性能的影响

针对铝合金易产生晶间腐蚀、表面硬度低、不耐磨损等缺点,利用金相显微观察、扫描电镜能谱测定、增重法、热震网格实验和失重法,以镀速、镀层结合强度、显微硬度以及耐蚀性为考核指标,研究了以硫酸镍为主盐、以次磷酸钠为还原剂、以焦磷酸钠为络合剂的预化学镀镍磷合金过程的工艺参数以及预化学镀和活化时间对镀层性能的影响。研究结果表明,所获得的活化-预化学镀镍磷合金前处理新工艺可显著提高镀层与基体的结合强度和沉积速率,同时得到的镀层组织结构致密均匀、硬度好、耐蚀性优良。     

化学镀Ni-Zn-P合金工艺的研究

对于石油化工中一些容器内表面的防腐,比较适宜的方法是化学镀Ni-Zn-P镀层.但目前化学镀锌镀速较慢,难以达到生产应用的要求;实验通过考察pH值、温度、硫酸锌、次磷酸钠等参数对镀速、镀层中锌的质量分数及镀液稳定性等影响,确立了适合于生产应用的化学镀Ni-Zn-P工艺.     

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。