无限微元法求霍尔槽初级电流分布

使用无限微元法对霍尔槽阴极初级电流分布进行了理论探讨，推导出霍尔槽阴极初级电流分布公式为：Ｄｋ＝Ｉｍ（Ａ＋Ｂｌｇ（Ｌｓｉｎθ＋α）），公式所得结果能正确解释电镀生产中的一些因素对镀层质量的影响，并对非直流电镀具有一定的指导意义。     

对霍尔槽阴极电流分布规律的再研究

采用最常用的１６种电镀工艺,通过测量霍尔槽阴极片上被分割的２０块小阴极条件的平均电流密度,再次研究了霍尔槽阴极电流的分布规律。所研究的电镀工艺包括３种镀锌、４种镀铜、５种镀镍、２种镀锡以及２种仿金镀。考察了描述上述分布规律的经验公式Ｄｋ＝Ｉ（ａ－ｂｌｇＬ）,并与所得实验结果进行比较,提出了不同电镀工艺的截矩ａ和叙率－ｂ的更准确数值。     

霍尔槽试片上电流分布的研究

本文采用直接测电流法在六种电镀液中,测量了容量250毫升的霍尔槽试片上的电流分布。根据测得的结果,对过去沿用的经验公式中的系数a、b进行了修正。     

赫尔槽阴极上电位分布规律初探

本文从赫尔槽阴极电流分布的经验公式:D_k=I(C_1-C_2lgl)出发,运用数学方法,逐步推导出赫尔槽阴极电位分布的规律,同时还对金属电沉积过程的机理进行了初步探讨。     

电镀电流参数在线测量

采用新型磁敏感原理专利技术所研制的低内阻电流传感器和电流测量仪,对霍尔槽阴极板的电流密度分布进行测量,并在镀锌生产线测量主电路电流及各挂具分电路的电流分布.     

霍尔槽阴极电流分布规律的研究

采用了工业最常用的氯化钾镀锌，碱性锌酸盐镀锌、氰化物镀锌、低氰化物镀锌、酸性镀暗镍、酸性光亮镀镍，酸性光这镀铜，氰化物镀我同镀钴体系所得镀氰化物预镀薄铜，二元仿金及三元仿金镀等十一种工艺，在霍尔槽中进行了阴极电流分布规律的研究。     

基于铜电解槽电流分布估计的烧板故障诊断

铜电解过程中,为了实现阴极棒“烧板”故障的自动诊断和电流分布的实时监测。提出依据红外成像原理,采用红外相机拍摄铜电解槽槽面图像,提取处理后图像阴极棒部位灰度值,结合现场试验建立灰度值与物体表面温度的数学模型,进而求出阴极棒表面温度。其次,应用偏最小二乘法(PLS)分区建立阴极棒表面温度与电流之间的数学模型,整合后得出阴极棒中电流的平方值与阴极棒表面温度、阴极棒坐标点和环境温度为拟线性关系。依据模型导出的阴极棒电流与现场实测电流对比表明:该方法能较准确地测量阴极棒中电流,实现了铜电解过程阴极棒中电流分布的实时监测。此外,能准确自动诊断出发生“烧板”故障的阴极棒,通过阴极棒中电流的监控也能对“烧板”故障进行预测,实现了“烧板”故障的自动诊断。从而降低了阴极棒“烧板”故障的发生,为企业带来了良好的经济效益。     

塑料基体酒石酸盐镀铅工艺

在含有酯键的塑料基体上经镀前处理,在酒石酸盐镀液中获得了铅镀层。实验中重点探讨了各种工艺条件（镀液组成及阴极电流密度）对阴极电流效率的影响;通过阳极极化曲线的测定,找出了络合剂游离量和搅拌与阳极临界钝化电流密度的关系;通过霍尔槽试验确定了最佳阴极电流密度范围。     

碱性镀锌镀层厚度均一性的研究

采用霍尔槽试验对碱性镀锌镀层厚度均一性的影响因素进行了研究.通过改善阴极电流分布、适当提高阴极电流密度、控制ρ(NaOH)与ρ(Zn2+)的比值、提高氢氧化钠质量浓度、降低锌离子质量浓度、控制镀液温度、提高RZ-5101A稳定剂的质量浓度和降低RZ-5101T净化剂的质量浓度均可提高镀层厚度均一性.改善碱性镀锌镀层厚度均一性的实质是通过控制镀液组成及工艺条件,降低阴极高电流密度区电流效率同时提高低电流密度区电流效率而达到的.     

轻研——1型赫尔槽的特点及其应用(下)

四、附有加热管的赫尔槽阴极试片上电流分布的探讨采用本所新制的赫尔槽,由于插入了加热管,因而阳极的宽度为4.5cm,比原来赫尔糟的阳极6.4cm要窄.是否可以采用原来常用的计算公式呢?下面我们对此作一简要讨论.在阴极上电流密度的分布情况与许多因素有关,大致有下述几方面:(1)镀液的性质(单盐、络盐、有无添加剂及添加剂的类型及含量);(2)所采用的电镀规范;(3)镀槽中阴阳极的尺寸、形状及其相互位置;     

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.     

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.     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.