微纳米材料对镀层硬度耐磨性的影响

通过制备Ni,Ni-SiC(微米)复合电镀,Ni-SiC(纳米)复合电镀,Ni-CNTs复合电镀,Ni-CNTs-SiC(微米)复合电镀,Ni-CNTs-SiC(纳米)复合电镀六种镀层,研究这六种镀层的显微硬度、耐磨性,并进行对比。分析了碳纳米管、碳化硅颗粒的加入对镀层的显微硬度和耐磨性的影响。试验结果表明,纳米复合电镀层表面平整光滑,其显微硬度、耐磨性也较纯镀镍镀层有显著的提高。     

浅谈摩擦与磨损

介绍了摩擦与磨损的定义;摩擦与磨损产生的原因、危害性及分类方法;减摩性及耐磨性的表征参数、测量方法;磨损的分类方法等.最后,以电镀及复合电镀为例,简单介绍了在表面处理技术中制备减摩镀层和耐磨镀层的优越性.     

氧化石墨烯对镀镍层耐磨性的影响

以氧化石墨烯为增强体,通过复合电镀的方法,在碳素钢表面制备了镍/氧化石墨烯复合镀层。研究了镀液中氧化石墨烯的质量浓度对镍/氧化石墨烯复合镀层的表面形貌、厚度、硬度及耐磨性的影响。结果表明:镀液中的氧化石墨烯通过提供异质形核核心的方式,使镍/氧化石墨烯复合镀层表面附着胞状突起,厚度和硬度增加,而磨痕宽度和磨损体积减小。与镀镍层相比,镍/氧化石墨烯复合镀层的耐磨性得到明显改善。     

工程车活塞杆用45~#钢电沉积Ni-WC纳米复合镀层的研究

在工程车活塞杆常用材料45#钢表面电沉积Ni-WC纳米复合镀层。分析了纳米复合镀层的表面形貌和物相结构,测试了纳米复合镀层的耐磨性和耐蚀性,并与45#钢的性能做比较。结果表明:纳米复合镀层表面较平整、均匀,结构较致密,主要由Ni相、WC相组成,Ni相的质量分数为81.25%,WC相的质量分数为6.53%,孔隙率低于0.5%,平均摩擦因数约为0.28;相同条件下,纳米复合镀层的腐蚀速率低于45~#钢的;纳米复合镀层能够提供有效的磨损防护和腐蚀防护,提高45~#钢的耐磨性和耐蚀性。     

中国专利

环保型纳米复合增强耐磨镀层生成液 本发明公开了一种环保型纳米复合增强耐磨镀层生成液,该镀层生成液不依靠电场力就可以在金属机件表面上生成一层由镍．磷纳米硬质陶瓷微粒组成的耐磨镀层。本发明与电镀硬铬相比具有成本低、耗能低、不污染环境的特点,特别是高性能纳米陶瓷共沉入合金镀层晶格中,大大增强了镀层的综合耐磨性能,比电镀硬铬层耐磨性提高了5倍以上。可替代电镀硬铬层对金属机件进行表面强化处理。     

活塞环材料的化学复合镀层与性能

本文研究了铸铁活塞环材料表面化学镀复合有SiC的Ni—P合金镀层。研究结果表明，Ni—P合金加热处理后，其Ni—P过饱和固溶体产生脱溶沉淀，析出第二相Ni3P，产生沉淀强化，SiC柱子复合后，产生分散强化，镀层硬度进一步提高，从而提高了耐磨性能。与镀铬、磷化处理相比，Ni-P合金层摩擦系数低，SiC镀层磨损体积低，抗磨能力强，耐磨性优良。     

电机轴套表面电镀强化及其耐磨性的研究

针对电机轴套易磨损导致其使用寿命缩短的问题,对其表面进行电镀强化。磨损试验结果表明:经电镀强化的轴套(简称强化轴套)的耐磨性受施镀参数的制约;采用优选的参数施镀,强化轴套的耐磨性较好,因磨损造成的外径缩减量和表面磨损速率均较低,且磨损较均匀。     

复合电镀镍钴铬合金工艺

一、前言随着电镀技术的发展,人们正在寻找各种功能性镀层.以满足产品的不同技术要求.为了在产品表面获得功能性镀层,往往采用复合电镀方法.复合电镀是在电镀溶液中加入非水溶性的固体微粒,并使其与主体金属在镀件上共沉积的电镀工艺.本文所介绍的镍钴铬合金电镀工艺就是采用复合镀方法,在镀件表面得到具有高耐磨性和抗高温性的功能性镀层.它已在生产中取得了应用.     

基于复合电镀工艺修复液压支架立柱的腐蚀破损

为增强液压支架立柱的耐蚀性,基于复合电镀工艺在其表面电沉积Ni-Al2O3镀层,并以腐蚀速率为评价指标,对处理后立柱表面的耐蚀性进行评价。结果表明:复合电镀修复后立柱表面的腐蚀速率较处理前的大幅降低,但受电镀工艺条件的影响;施加适宜功率的超声波搅拌和低电流密度,有利于获得良好的修复效果。     

Ni-ZrO2复合镀层的腐蚀摩擦学性能研究

用电镀方法制得Ni-ZrO2复合镀层,研究电镀Ni-ZrO2复合镀层的结构以及其硬度、耐磨性、抗腐蚀性与电镀电流密度的关系。结果表明：复合镀层的显微硬度比纯镍镀层硬度成倍提高,复合镀层耐磨性比镍镀层提高20％以上;抗腐蚀性提高70％以上。X射线衍射结果显示,复合镀层由Ni及非晶ZrO2组成。Ni相为面心立方晶体结构,晶格常数为0．353nm,小于纯镍镀层,晶粒尺寸为23．8nm,大于纯镍镀层。     

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.     

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。     

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。