镀铬钢板表面特性对涂饰性的影响

在一定温度下对镀铬钢板烘烤一定时间后进行涂漆,主要工序为除油、酸洗、电镀铬、电镀氧化铬和涂漆。研究了氧化铬层铬含量对镀铬板涂饰性的影响,探讨了烘烤时间和温度对镀铬板表面形貌、耐蚀性及其与漆膜之间结合力的影响。当氧化铬层铬含量为19.5~25.0 mg/m2时,镀铬板表面具有较好的涂饰性。烘烤温度和烘烤时间对镀铬板表面形貌和耐蚀性无明显影响,但对氧化铬层与漆膜之间的结合力有着明显的影响。在200°C下对镀铬板烘烤20 min后,镀铬板的涂饰性最佳。     

宝钢镀铬板的表面形貌与缺陷分析

基板表面质量对镀铬板的表面形貌及性能影响较大。生产中部分产品目视即可看出有白点或表面亮度不够,与其他区域存在明显差异。这些区域极易出现锈斑。针对这些问题,采用扫描电子显微镜对镀铬板的表面形貌进行观察,并用能谱仪分析了缺陷处的元素组成,确定了影响镀铬板表面形貌的因素及出现缺陷的原因。同时,分析了工艺条件和基板形貌对镀铬板性能的影响。     

二次冷轧基板及其镀铬板耐蚀性研究

通过塔菲尔曲线测试、中性盐雾试验和浸泡腐蚀试验研究了二次冷轧基板及其镀铬板的腐蚀行为.结果表明:镀铬板的耐蚀性优于二次冷轧基板.二次冷轧基板和镀铬板的腐蚀均优先发生在表面缺陷处.二次冷轧基板处于中性盐雾气氛或40°C的3.5％NaCl溶液中时,逐渐从局部腐蚀转变为大面积严重腐蚀甚至全面腐蚀.镀铬板处于上述两种介质中时发生局部腐蚀,随时间的延长,局部腐蚀现象加剧.     

光度法测定镀铬板表面金属铬的质量浓度

利用电解将镀铬板表面金属铬剥离完全,采用二苯卡巴肼分光光度法测定镀铬板表面金属铬的含量。实验中,探讨了电解电流、各显色条件对测定铬离子含量的影响,确定最佳试验条件。在优化条件下,测得镀铬板表面金属铬的平均质量浓度为94.09 mg/m2,其相对标准偏差为1.22%(n=5),对镀铬板试样进行加标回收,测得铬的加标回收率在97%~102%之间,说明该方法准确度较好,能满足日常分析要求。     

镀铬板表面初始腐蚀机制的研究

为了解镀铬板的初始腐蚀机制,利用扫描电子显微镜(SEM)、X射线能量色散谱仪(EDS)和X射线光电子能谱仪(XPS)研究了分别在25℃和40℃的3.5%NaCl溶液中浸泡不同时间后镀铬板的腐蚀形貌和组成。结果表明:镀铬板腐蚀优先发生在缺陷处,这是由于缺陷处粗糙度较大,容易吸附大量氯离子。镀铬板表面钝化膜主要由Cr₂O₃、Cr(OH)₃和金属铬组成。镀铬板在3.5%NaCl溶液中浸泡后,表面氧化膜以FeO和Fe₂O₃为主,随着浸泡时间的延长,二价Fe逐渐向三价Fe转变。     

不锈钢模具板化学蚀刻、抛光和电镀铬研究

研究了不锈钢模具板的化学蚀刻、化学抛光和电镀铬工艺。分析了影响蚀刻、化学抛光和电镀铬质量的因素,得到了化学蚀刻、化学抛光及电镀铬最佳工艺参数和操作规范。该工艺可以用于各种类型不锈钢的化学蚀刻、化学抛光和电镀铬处理。     

冷轧薄板连续电镀铬机组

为满足市场和冷轧薄板厂自身发展需求,进一步增加产品规模、扩大品种范围,在食品包装行业采用镀铬板代替镀锡板.为便于镀铬板的生产,设计、组建、投产了连续镀铬机组.该机组经三年时间的生产实践,其产能已达到设计水平,产品质量满足了用户要求.对该机组作简要的介绍,以供同行参考.     

深槽带钩类零件批量镀铬挂具的设计

通过设计一种一字前后夹板型组合挂具来实现槽针的批量镀铬。受制于槽针的结构特点,没有合适的批量镀铬挂具。同时,批量镀铬时容易出现过烧、结瘤等现象。对此,设计了一种组合挂具,不仅加以引流铜丝和物理屏蔽遮挡板设计,还改进了阳极板与挂具的相对位置并隔离了超出的阳极。实验结果表明:该组合挂具能实现槽针的批量镀铬;辅助阴极设计在很大程度上改善了针钩处的烧焦现象,针槽内壁及针钩处都能获得一层光亮、平滑的镀铬层;槽针批量镀铬后的合格率在95.0%以上。     

镀铬板生产线镀液净化技术

测试了宝钢电镀铬机组镀液中杂质颗粒的粒度分布,观察了镀液中杂质颗粒浓度的变化情况,提出了一种去除镀液中固体杂质的方法,并设计了一套净化过滤系统.经实际使用,过滤后的镀液能满足高品质镀铬板生产的要求.     

镀铬板工业化生产实践

0 前言 随着锡的用途不断扩大,其资源正日趋匮乏.镀铬薄钢板被认为是目前代替镀锡板最为理想的材料.镀铬板是将冷轧薄钢板在铬酸溶液中进行阴极还原,在钢板表面形成一层极薄的金属铬和水合氧化物铬膜的产品.     

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.     

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。