镁合金电镀Ni-Al_2O_3薄膜的研究

采用电镀方法对镁合金进行表面镀膜处理,间接提高其硬度和耐蚀性。借助硬度计和浸泡法对表面电镀Ni-Al2O3薄膜的镁合金的硬度和耐蚀性进行了测试。结果表明:表面镀膜能一定程度提高镁合金基体的硬度和耐蚀性,但此两项性能的彰显受电镀参数的影响。加载适宜的电流密度且电极水平面对面放置时,表面电镀Ni-Al2O3薄膜的镁合金的硬度较高,耐蚀性也较好。     

镀铜优化对AZ91D镁合金疏水膜性能的影响

使用HF在AZ91D镁合金表面刻蚀微纳结构,并采用镀铜方法加以优化,然后以硬脂酸为主要成分在表面构成疏水膜,提高镁合金的耐蚀性能。从沉积温度、时间和电流密度等因素优化电镀铜工艺,使用激光共聚焦显微镜、扫描电子显微镜和水接触角测量仪研究镁合金的表面形貌、粗糙度和疏水性能。结果表明,电镀铜可优化镁合金表面的微纳结构,最佳的镀铜工艺为温度10℃、时间15 min、电流密度为0.25 A/dm~2。镁合金进行疏水化处理后,接触角最大可达142.3°。     

镁合金件有机防护涂层的耐腐蚀性能研究

为提高镁合金的耐腐蚀性能,利用复合有机涂层技术在ZM5铸镁合金表面制得防腐涂层。研究了镁合金的前处理、有机防腐涂装以及装饰性涂装工艺条件及其涂膜性能。利用化学转化膜对镁合金进行表面处理,再用复合有机涂层提高镁合金的防腐性能。结果表明:该有机涂层体系对镁合金有较好的腐蚀防护作用,化学转化膜可以提高镁合金与有机涂层的结合力并提高其耐腐蚀性。     

表面处理期刊纵览

Platiing＆Surface Finishing 2005,Vol．92,No．2 电镀生产中的一些问题及其解决办法——第18部分,镁合金电镀工艺咨询,表面精饰中的替代工序及工艺,金-锡电镀液稳定性研究,一种可以提高电机性能的铁-钴-钒合金叠层的电抛光技术。     

镁合金表面合金化及电泳涂装工艺

介绍了镁合金表面合金化及电泳涂装工艺流程。讨论了镁合金表面合金化的工艺配方及其操作步骤。研究了镁合金的前处理、防腐涂装以及装饰性涂装工艺条件及其涂膜性能。为镁合金产品的防腐装饰提供了新的途径。     

金属零件电镀表面处理工艺

金属零件是工业设备的重要组成部分，生产制造过程中使用电镀工艺对其表面进行处理后，能够保障导热、导电等性能，预防表面腐蚀，延长使用寿命。概述了金属零件电镀内容，剖析了电镀表面处理工艺。以钢铁缺件为例，对表面处理工艺的应用进行了讨论。     

镁合金高耐蚀表面处理技术的研究进展

[目的]随着加工技术水平的不断提高,镁合金应用范围迅速扩展,市场需求不断增长。然而镁合金化学活性高,在环境中极易发生腐蚀而造成金属部件失效。因此镁合金的防腐处理至关重要。[方法]综述了改善镁合金耐蚀性的几种常用表面处理技术的研究进展,包括化学转化、微弧氧化、电镀、电泳沉积、溶胶-凝胶处理、水热处理和喷涂。[结果]对镁合金进行适当的表面处理能够显著提高其耐蚀性。[结论]目前镁合金表面防腐处理已取得一定的进展,但还有许多待改进之处。     

封闭工艺对镁合金磷酸盐转化膜的影响

在镁合金上制备磷酸盐转化膜,并进一步用硅酸钠溶液对其进行封闭处理。采用单因素试验方法,确定了硅酸钠的质量浓度、封闭时间及封闭温度,得到了最佳的工艺参数。通过点滴试验、扫描电镜和电化学测试,研究了封闭处理后镁合金的耐蚀性、表面形貌及电化学性能。镁合金磷酸盐转化膜的最佳封闭工艺条件为:硅酸钠5g/L,温度80℃,时间20min。经封闭后,膜层的表面形貌有所改善,并且自腐蚀电位正移,耐蚀性得到提高。     

高分子表面金属化技术

高分子表面金属化是对高分子材料表面进行改性处理使其具有良好物理性能、力学性能及金属光泽的表面技术,广泛应用于高分子导电、薄膜修饰、电磁屏蔽等领域。本文综述了高分子表面金属化的两大类技术方法,即干法镀膜和湿法镀膜。介绍了几种典型的表面处理技术,如真空镀膜、喷涂金属转移法、化学镀、化学还原金属化以及电镀,并总结了它们的技术特点以及在科学研究和工业生产应用中的难点。阐明了从传统电镀技术发展而来的高分子表面直接电镀工艺的优势,直接电镀工艺省去了电镀前的活化工序,缩短了工艺时间,避免了电镀前工艺对环境造成的污染,成为高分子表面金属化技术发展的新方向。     

不锈钢玻璃封接组件化学抛光工艺

在连接器产品设计中,需要对形状复杂的不锈钢玻璃封接组件进行表面处理,使零件表面达到镜面光亮效果,才能在后续电镀过程中更好地保证产品的性能。根据实际生产过程中的需求,研究了不锈钢玻璃封接组件电镀前表面处理达到镜面光亮效果的工艺过程,探索出一种新型环保不锈钢化学处理液,讨论了溶液各组分和温度、处理时间等工艺参数的影响。通过实验和生产验证,该不锈钢玻璃封接组件镜面化学处理液的最佳工艺条件为:40 m L/L硫酸,80 g/L添加剂XSY,θ为80℃,t为30~50 s,其表面可达到镜面般光亮,且封接玻璃表面无裂纹,保障其表面在电镀过程中具有良好的镀层结合力和表面质量,满足了设计对产品的性能要求。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.