钕铁硼磁体表面高耐蚀性锌铝涂层的制备及性能研究

通过浸涂-离心工艺在NdFeB磁体表面制备了ZnAl涂层,对涂层形貌、元素成分及织构进行了分析,研究了ZnAl/NdFeB磁体的极化曲线、高温老化和耐盐雾性能,测试了磁体涂覆后磁通量的变化。结果表明,NdFeB磁体表面制备的ZnAl涂层中Zn、Al以金属单质的形式存在,且以片状形态堆叠于磁体表面。涂覆后,磁体在3.5%NaCl溶液中的腐蚀电流密度降低了2个数量级。高温高湿老化400 h和中性盐雾试验720 h后,ZnAl/NdFeB磁体表面无变化。NdFeB磁体的磁通在涂覆后只降低了0.14%～0.26%,说明ZnAl涂层对NdFeB磁体的磁性能影响甚微。     

机械装备用6xxx系铝合金在氯盐溶液中的腐蚀行为及其防护

以机械装备用6xxx系铝合金为研究对象,通过测量腐蚀坑数量、深度及开口面积,并分析腐蚀形貌特征,对6xxx系铝合金在氯盐溶液中的腐蚀行为进行了研究。结果表明:在氯盐溶液中浸泡后,6xxx系铝合金表面腐蚀坑数量随浸泡时间的延长而增多,腐蚀坑的最大深度和最小深度相差较大;腐蚀后6xxx系铝合金表面形成带孔洞的疏松结构,腐蚀产物的化学成分以铝和氧为主。对比实验证实了通过化学镀-镍-铜磷合金对6xxx系铝合金进行表面防护是可行的。     

后处理对离子液体电镀铝合金涂层耐蚀性能的影响

为了获得最佳的耐蚀性能,研究了喷丸和化学氧化后处理方法对离子液体电镀铝合金涂层微观形貌和耐蚀性能的影响,并综合对比了离子液体电镀铝合金涂层、离子镀铝及电镀镉-钛合金三种涂镀层的耐蚀性和与铝合金接触腐蚀性能。研究结果显示,喷丸处理对离子液体电镀铝合金涂层的耐蚀性没有明显的增强效果,三价铬化学氧化处理则能够大幅提高其耐蚀性能;离子液体电镀铝合金涂层耐蚀性优异,略低于电镀镉-钛合金涂层,略优于离子镀铝涂层;离子液体电镀铝合金涂层与7050铝合金阳极化试样接触腐蚀敏感性等级为A级,不会引起电偶腐蚀,与离子镀铝相当,优于电镀镉-钛合金涂层。     

NdFeB塑料粘结磁体的研究进展

主要从粘结磁体的反应共混、耐腐蚀性、加工流变性能和动态性能4个方面论述NdFeB粘结磁体的最新研究进展.NdFeB粘结磁体既拥有NdFeB磁体较好的磁性能,又能表现出粘结剂(主要是塑料)固有的流变性能,是未来NdFeB磁体发展的方向.     

硝酸根离子对铝在盐酸溶液中的缓蚀作用

用失重法和动电位极化曲线方法研究了硝酸根离子对工业纯铝在1．5mol／L HCl溶液中的缓蚀作用和机理,讨论了其在铝表面的吸附。结果表明,对铝在盐酸溶液中的腐蚀,硝酸根离子是很一种很好的缓蚀剂。当硝酸根离子浓度较低时,其缓蚀效率随着浓度增加而增大,随后增加硝酸根离子,缓蚀效率基本稳定;当硝酸根离子浓度较大时,缓蚀效率在测量时间内随着腐蚀时间的延长而增大。硝酸根离子通过抑制铝的阴极反应而起到缓蚀作用,其在铝表面的吸附符合Freundlich吸附等温式。     

离子热合成磷酸铝分子筛AlPO4-11的研究

应用离子热合成法以溴化N-烷基取代咪唑离子液体为反应介质,合成了AlPO4-11分子筛,考察了离子液体用量、磷铝比、HF用量、晶化时间、晶化温度等条件对分子筛结构的影响,并对离子液体进行回收再利用,通过X射线衍射、扫描电子显微照片、红外光谱等手段进行表征。结果表明,在磷铝比1.5~4范围内,能合成出具有独特晶粒形貌的AlPO4-11分子筛,且离子液体能多次循环利用。     

离子热合成磷酸铝分子筛AIPO4-11的研究

应用离子热合成法以溴化N-烷基取代咪唑离子液体为反应介质,合成了AIPO4-11分子筛,考察了离子液体用量、磷铝比、HF用量、晶化时间、晶化温度等条件对分子筛结构的影响,并对离子液体进行回收再利用,通过X射线衍射、扫描电子显微照片、红外光谱等手段进行表征.结果表明,在磷铝比1.5～4范围内,能合成出具有独特晶粒形貌的AIPO4-11分子筛,且离子液体能多次循环利用.     

离子液体在有色金属冶金中的应用

离子液体作为一种新型绿色溶剂在有色金属提取与分离中有着重要作用. 本文着重介绍了离子液体在金属及其氧化物的溶解与腐蚀、活泼金属镁铝钛电沉积及黄铜矿湿法冶金方面的应用. 研究工作显示,离子液体的应用可以使冶金反应在室温或接近室温下进行, 可大幅度降低能耗和生产成本, 减少环境污染.     

铝在高压直流输电系统中高电压高温下的腐蚀行为研究

高压直流输电换流阀的内冷水系统中,铝散热器在高压高温下会腐蚀进而引起均压电极发生氢氧化铝结垢,导致生产异常。此状态下的铝的腐蚀行为少有报道。本文研究了与散热器相同材质的铝电极在高电压、高温下于蒸馏水和弱碱性溶液中的腐蚀行为及其电化学反应规律。理清了铝的电化学腐蚀行为,建立铝在中性溶液中失去电子的反应的模型。建立了铝电极的腐蚀反应的等效电路,计算了各历程的阻抗,发现腐蚀的控制步骤为OH^-穿过沉淀层。研究表明,在3.35mmol/L氨水溶液中具有最低的腐蚀趋势,其腐蚀电位为-0.731 V,腐蚀电流密度为7.667×10^-7 A/cm²,塔菲尔斜率为5.328。此时电化学反应的阻抗最大,其腐蚀速度最低。铝电极表面会覆盖氢氧化铝等腐蚀产物,其限制离子的扩散,减缓腐蚀趋势。由此建议在保证低电导率的前提下调整内冷水的pH,来改善换流阀内冷水系统的防腐能力。     

铁细菌对聚驱采出体系管线钢腐蚀行为研究

采用电化学测试技术和表面分析技术,研究了无菌体系以及铁细菌（FB）下聚驱采出体系管线钢的腐蚀行为。结果表明,无菌体系下碳钢表面腐蚀程度较弱。随浸泡时间的增加,其腐蚀速率前期迅速增大,随后腐蚀速率降低,浸泡后期腐蚀速率缓慢增大。随浸泡时间的增加,FB体系下碳钢表面发生了局部腐蚀,碳钢的腐蚀速率呈增大、减小和增大的趋势。微生物在碳钢表面形成的生物膜抑制了碳钢电化学的阴极反应,促进了电化学的阳极反应。     

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。