现场表面拉曼光谱研究Ni-P合金电沉积机理

由于Ｎｉ Ｐ合金具有许多优越的物理和化学性能 ,如高的耐蚀性［１］、好的电催化特性［２,３］以及好的非磁特性［４,５］,人们对这种合金的沉积方法进行了大量的研究．磷是一种不能从水溶液中单独进行电沉积的元素 ,但它很容易和铁组元素共沉积．为了解释这一现象 ,Ｂｒｅｎｎｅｒ曾提出直接机理［６］．认为镀液中磷的含氧酸 (根 )直接在电极上还原成合金中的磷．然而 ,磷不能用电化学方法以纯态沉积出来,所以直接机理没有被广泛接受．第二种是由Ｆｅｄｏｔ′ｅｖ等提出的间接机理［７］,认为磷的含氧酸（根）首先还原成磷化氢（ＰＨ…     

电沉积Ni—Mo—P合金镀层在NaCl溶液中的腐蚀特性

用失重法，阳极率曲线，Ｘ－光电子能谱（ＸＰＳ）以及俄歇电子能谱（ＡＥＳ）研究了电沉积Ｎｉ－Ｍｏ－Ｐ合金镀层在５％ＮａＣｌ溶液中的腐蚀特性，非晶态Ｎｉ－Ｍｏ－Ｐ合金镀层比晶态Ｎｉ－Ｍｏ－Ｐ合金镀层有较低的腐蚀速度阳极极化曲线表明，Ｎｉ－Ｍｏ－Ｐ合金镀层中，镍的摩尔分数国０．７１９～０．８６８时，随镀层中磷含量的增加，腐蚀电位正移，而活化区的峰电流随镀层中钼含量的增加而增加，磷含量的活化区的峰电流以及     

半导体硅上电沉积Ni-Pd-P薄膜及其结构

采用控电位的沉积方式在半导体硅上制备出ＮｉＰｄＰ薄膜,结果表明镀液中Ｈ３ＰＯ３含量的增加对Ｐ、Ｎｉ的析出有促进作用,对Ｐｄ的析出有抑制作用．随ｐＨ值的升高,镍含量不断升高,Ｐｄ、Ｐ含量不断下降．Ｐ含量对薄膜内应力有很大影响,含Ｐ质量分数为１４９％的ＮｉＰｄＰ镀层表面上有许多裂缝,当Ｐ含量增加到２６１％时,镀层表面的裂缝已基本消失,继续增加Ｐ含量到３５０％时,裂缝完全消失．ＮｉＰｄＰ镀层的结构与其组成密切相关,Ｐ含量小于２００％的ＮｉＰｄＰ镀层形成的是面心立方结构的固溶体．Ｐ含量大于４００％的薄膜为非晶态结构．     

无电解镀镍磷非晶态合金的近边结构研究

用ＤＴＡ，ＸＲＤ和ＥＸＡＦＳ方法研究无电解镀镍磷合金层结构，其中含Ｐ１０％（重量百分比）左右的Ｎｉ－Ｐ合金层是非晶态合金固溶体，Ｎｉ，Ｐ之间存在共价键作用，Ｎｉ－Ｎｉ键长０．２５ｎｍ，Ｎｉ－Ｐ键长０．２８ｎｍ经４００℃热处理１后的含Ｐ１０％的Ｎｉ－Ｐ镀层是Ｎｉ３Ｐ晶态与Ｎｉ－Ｐ非晶态的混合物，ＥＸＡＦＳ方法给出了镍磷合金层的结构，键长和配位原子情况，体现出ＥＸＡＦＳ方法在研究金属结构尤其是非晶态金     

纳米晶镍—钼合金电沉积层的结构与性能

通过控电流沉积制备出纳米晶镍钼合金沉积层,沉积层的ＸＲＤ、ＸＰＳ结果表明,纳米晶镍钼合金沉积层存在较大的晶格畸变,其微晶尺寸为１７ｎｍ,纳米合金各元素的结合能发生了不同程度的位移．在３０％的ＫＯＨ溶液中纳米晶镍钼合金电极对析氢反应表现出较高的电催化活性．电化学交流阻抗谱表明,析氢过程按ＶｏｌｍｅｒＨｅｙｒｏｖｓｋｙ机理进行．     

双四氮杂大环镍(Ⅱ)配合物催化的化学振荡反应

四氮杂大环配合物是生物体内一些金属酶结构单元的模拟物,四氮杂大环铜和镍的配合物可以催化化学振荡反应。近年来,此类反应被广泛地研究［１～４］。目前已报道的作为化学振荡反应催化剂的四氮杂大环配合物的配体都是单环。我们发现一种双四氮杂大环镍(Ⅱ)配合物Ｎｉ２Ｌ（ＣｌＯ４）４［Ｌ为双(１１,１３二甲基１,４,７,１０四氮杂１０,１３环十三二烯１２亚甲基)］可以作为化学振荡反应的催化剂,本文研究了Ｎｉ２Ｌ（ＣｌＯ４）４催化ＮａＢｒＯ３ＣＨ２（ＣＯＯＨ）２（ＭＡ）Ｈ３ＰＯ４体系的化学振荡反应。１实验部分实验试剂:丙二酸…     

钨含量对Ni-W合金镀层结构的影响

对于用电镀方法获得的非晶态合金镀层,普遍认为合金元素的加入破坏了原基体金属晶格的规则排列,形成非晶．而且只有合金镀层的组成达到临界限度时,才能非晶化,镀层的合金组成是其能否形成非晶态的决定性因素［１］．但镀层的合金组成与镀层结构的关系未见详细报道．本文用Ｘ射线衍射法和扫描电镜对ＮｉＷ镀层的结构进行了初步探讨．所用仪器：日本理学Ｄ／ｍａｘＲＢ型Ｘ射线衍射仪（ＣｕＫα靶,λ＝０－１５４１８ｎｍ,管流２０ｍＡ,管压２５ｋＶ,扫速２°／ｍｉｎ）;日本ＥＤＡＸ９１００型扫描电镜．基础镀液：Ｎａ２ＷＯ…     

p—Si上电沉积Ni—W—P薄膜的结构与热稳定性

研究了ｐ－Ｓｉ上恒电流沉积Ｎｉ－Ｗ－Ｐ合金薄膜组成与结构的关系，讨论了镀层的组成、结构随沉积时间的变化．测定了非晶合金的晶体结构随热处理温度的改变以及ＤＴＡ曲线，结果表明，非晶Ｎｉ－Ｗ－Ｐ合金在晶化过程中形成两个纳米超微晶相，非晶Ｎｉ－Ｗ－Ｐ薄膜的热稳定性远高于通常使用的非晶Ｎｉ－Ｐ薄膜．     

电镀Fe－Cr－Ni合金显微结构研究

电镀Ｆｅ－Ｃｒ－Ｎｉ合金显微结构研究①李东林＊刘建平郭芳洲华建荣（南方冶金学院化工系,江西赣州３４１０００）Ｆｅ－Ｃｒ－Ｎｉ合金,一直是电镀工作者研究的对象［１,２］．Ａ．Ｍ．Ａｎｄｅｒｓｏｎ［３］等人从多种Ｃｒ（Ⅲ）的水溶液中镀出了Ｆｅ－Ｃｒ－Ｎｉ...     

镍钨磷合金电结晶机理及其镀层结构与显微硬度

应用循环伏安,恒电位阶跃和Ｘ射线衍射（ＸＲＤ）等方法了Ｎｉ－Ｗ－Ｐ合金电沉积特点和镀层结构与显微硬度,结果表明,在以柠檬酸铵为配体的溶液中,Ｎｉ－Ｗ－Ｐ合金 层较Ｎｉ－Ｗ合金有较低的电化学活性,根据电位阶跃的ｉ－ｔ曲线分析表明,在玻碳电极上Ｎｉ－Ｗ－Ｐ合金电结晶过程遵从扩散控制瞬时成核三维成长模式进行,随着过电位的增加,电极表面上晶核数增多,ＸＲＤ试验结果表明,Ｎｉ－Ｗ－Ｐ合金镀层呈现明显的非晶态特征,所获得的Ｎｉ－Ｗ－Ｐ合金电沉层的显微硬度在４５０ｋｇ．ｍｍ＾－２左右。     

基于有机磷酸类MOFs前驱体制备Ni2P/C复合材料

以镍为金属中心、 对二甲苯二磷酸为有机配体, 构筑了一种有机磷酸类Ni-MOF前驱体, 再经过一步碳化, 原位制备出多孔碳包覆Ni₂P纳米颗粒的复合材料. 该复合材料保留了前驱体的片状形貌, 比表面积可达202 m²/g, 复合材料中的Ni₂P纳米颗粒具有良好的结晶度, 颗粒均匀且无团聚现象. 在锂离子电池性能测试中, 该Ni₂P/C复合结构在缓解材料体积膨胀的同时提高了材料的电子和离子电导率, 进而提高了材料的电化学性能. 在0.2 C的电流密度下, 材料首次充、 放电比容量分别为247和226 mA·h·g^-1, 库仑效率可达91.7%, 循环200圈后, 库仑效率接近100%.     

Proton conduction in indium hydrogensulfate and hydrous zirconia composites

Solid composite proton electrolytes based on indium hydrogensulfate and hydrous zirconia are studied. A composite effect is observed in these systems: their proton conductivity is higher than in the starting components. Maximal conductivities are achieved at a comparatively low concentration of hydrous zirconia (10% wt %) in composites heat-treated at 373 K. The increasing surface basicity of hydrous zirconia as a result changing its deposition pH noticeably improves the low-temperature conductivity of the composites. Irreversible processes that decrease the conductivity occur in composites even during treatment at temperatures above 373 K. A third component (neutral indium sulfate) only decreases the conductivity.     

球磨La2Mg17+x％Ni(x=50,100,150,200)复合贮氢合金的电化学性能研究

研究了球磨制备的La2 Mg17+x％Ni(x =50,100,150,200)复合贮氢合金的电化学性能.XRD分析表明:随着Ni含量的增加,复合合金的晶体结构逐渐转变为非晶结构.电化学测试显示:球磨制备的La2Mg17+x％Ni复合贮氢合金在首次循环后即可达最大放电比容量,合金具有较好的活化性能;复合合金的放电比容量也随Ni粉加入量的增加而增大.在经过60h球磨后制得的非晶态的La2 Mg17+ 200％ Ni复合贮氢合金,其303 K下放电比容量为353.1 mAh·g-1.电化学放电比容量的提高应归因于非晶结构的形成以及Ni粉对表面状态的改变.     

Mechanical behavior of basalt and glass textile composites at high strain rates: A comparison

The aim of this paper is to study and compare the mechanical behavior of woven basalt and woven glass epoxy composites at high strain rates, in order to assess the possibility of replacing glass fiber composites with basalt fiber composites for aircraft secondary structures, such as radomes, fairings, wing tips, etc. Both composites were produced using the same epoxy matrix, the same manufacturing technique, and with comparable densities, fiber volume fractions, and static stiffnesses. Dynamic tensile and shear experiments were performed using a split Hopkinson tension bar, in addition to reference quasi-static experiments to compare both material behaviors over a wide range of strain rates. Normalized results with respect to the material density and fiber volume fraction showed that basalt epoxy composite had higher elastic stiffness, ultimate tensile strength, ultimate tensile strain, and absorbed energy in tension compared to glass epoxy composite. This suggests a promising potential in replacing glass fibers composites with basalt fiber composites in aircraft secondary structures and, more generally, components prone to impact. However, for the basalt epoxy composite, improvements in the fiber-matrix adhesion and in the manufacturing technique are still required to enhance their shear properties compared to glass fiber composites, and fully exploit the potential of basalt epoxy composites in aeronautical applications.     

氢氧化镍/多壁碳纳米管复合材料的溶剂热法制备及电容性能

采用溶剂热法制备了氢氧化镍/多壁碳纳米管[Ni(OH)2/MWCNTs]复合纳米材料;借助X射线衍射仪和透射电镜分析了产物的结构和形貌,利用循环伏安测试测定了复合材料的电容特性.结果表明:片状β-Ni(OH)2较好地附着在MWCNTs上;复合样品的循环伏安行为明显有别于空白样品Ni(OH)2,峰电流较高.这表明引入MWCNTs可改善Ni(OH)2的电化学性能.与此同时,当MWCNTs的质量分数为10%时,相应的Ni(OH)2/MWCNTs复合物的氧化还原峰电位差最小,循环可逆性最佳.     

Electroless deposition and some properties of Ni–Cu–P and Ni–Sn–P coatings

In this review, a summary of our published results, completed with new unpublished data are considered together with some of other authors’ publications, making an attempt to reveal the mechanism of the third element co-deposition in electroless Ni–P plating and to define its influence on the ternary coatings’ properties. A model explaining the triple role of Cu added to the solution for electroless (EL) Ni–P plating is described: as a stabilizer [Cu(I)]; as an accelerator; and as a stability-affecting agent, forming a dispersed solid phase in the solution. The disproportionation reaction of Cu(I) has been taken into account. A planned experiment was performed using full-effect factorial design with two levels of three process variables, and the response surfaces were constructed. The interaction between the factors was revealed. The results are in harmony with the aforementioned model. In low-tin Ni–Sn–P coatings, the alloy components are uniformly distributed both on the surface and through the thickness. In contrast, high-tin coatings exhibit three-dimensional areas enriched in Sn and impoverished in Ni and P. As the reason for their formation, the disproportionation reaction of Sn(II) is suggested, supposed to be locally predominant over the hypophosphite oxidation. EL deposition of pure Sn onto Ni–Sn–P substrates is shown. The inclusion of Cu or Sn in EL Ni–P increases the thermal stability of amorphous state, ensures the preservation of a paramagnetic behavior and improves the corrosion resistance. Dedicated to the 70th birthday of Professor A. Vaskelis.     

Quantum Chemical Study on Geometry and Property of Cluster Ni_4P

1INTRODUCTION Amorphous alloys attractive to scientists have worked in the field of materials and catalysts since they have many excellent physical and chemical pro-perties,such as high magnetic susceptibility,high specific heat,high strength,ductile in compression,low coefficient of friction,high corrosion resistance,super plasticity within the range,ferromagnetism and super conductivity[1~5].Especially,amorphous alloys as catalytic materials have shown either hig-her activity or selectiv…     

Properties of poly(vinyl chloride)/wood flour/montmorillonite composites: Effects of coupling agents and layered silicate

Organomodified montmorillonite (OMMT) was prepared using cetylalkyl trimethyl amine bromide. OMMT and wood flour (WF) were surface-modified by silane coupling agent. They were melt-blended with polyvinyl chloride (PVC) and extruded into wood-plastic composite samples using one conical twin screw extruder. The effects of their contents on the composite mechanical properties were investigated. X-ray diffraction, transmission electron microscopy and scanning electron microscopy observed intercalation and dispersion of the OMMT. FTIR and X-ray photoelectron spectroscopy were used to analyze the silane-modification effects. The possible reaction mechanisms were proposed. After wood flour was modified by 1.5 phr silane, the impact strength and the tensile strength of wood flour-PVC composite were increased by 14.8% and 18.5%, respectively. Mechanical tests showed that the addition of OMMT did not enhance the untreated wood flour-PVC composites. However, adding 0.5% OMMT did improve the mechanical properties of the treated ones. The grafting improved the interfacial compatibility between components producing higher properties of the composites. Further addition of OMMT reinforced the composites. Too higher contents of silane and OMMT impaired some properties because of weak interfacial layer and higher concentrated stress. Cone calorimetry showed that the fire flame retardancy and smoke suppression of composites were strongly improved with the addition of OMMT.     

锂离子电池SiAg复合材料研究

应用机械合金化法制备了两种不同组分的Si-Ag复合材料.扫描电镜(SEM)、X射线衍射(XRD)、充放电测试和循环伏安法对该材料的微观形貌、相组成及电化学性能.研究表明,组成原子比为1∶1的复合材料具有很好的循环稳定性和可逆性,在0.2mA·cm-2的电流密度下,经50周循环后可逆容量仍保持300mAh·g-1.实验发现,借助充放电控制,即可有效提高合金材料的循环性能.     

Effect of the composition and structure of metal oxide nanocomposites on the sensor process when detecting reducing gases

The effect the nature of metal oxide components, quantitative and qualitative composition, structure of binary metal oxide nanocomposites, and temperature have on the physicochemical processes that occur during the detection of reducing gases and are responsible for the efficiency and selectivity of sensors based on these composites is considered. The relationship between the mechanisms of the conductivity and sensor effect in composites is determined. The crucial role of electron transfer between metal oxide components with different work functions leading to the mutual charging of these components is noted. The mechanisms of electronic and chemical sensitization of the sensor effect in composite materials consisting of metal oxides with various electronic and chemical properties are discussed. The important role of the way composite materials are obtained is noted. The effect of small clusters of one oxide on the surfaces of nanoparticles of other components, formed during the synthesis of composites via impregnation, is studied. Systems consisting of composite nanofibers of the core–shell type based on metal oxides of different natures are considered. It is shown that by changing the nature of the components and their relative location in the nanofibers, the sensitivity and selectivity of a sensor system can be adjusted for different chemical compounds.