石墨炉原子吸收光谱法测定食品中镍含量的研究探讨

通过对武汉市部分地区３４种，１７０件样品中镍含量的测定结果证明，该方法上有操作简便，准确，灵敏，干扰较少等优点，是分析测定食品中镍含量理想方法之一。该方法灵敏度为２．５１－１０＾－３／ｐｐｂ。方法添加回收率分别为（添加两种不同浓度的镍标准）８１．２５－１０７％，９０．５－１０５％，变异系数为（测定两种质控标样各５份）４．１￣７．７％，检出限为１．３２ｐｐｂ。     

钙镁磷肥副产物磷铁中镍的测定

在pH=6.2的HAc-NaAc缓冲溶液中,镍与偶氮胂Ⅲ形成1∶3的蓝色配合物。且镍含量在0~1μg/mL符合比尔定律,在620 nm处有最大吸收。在焦磷酸钾存在下测定了镍磷铁中镍的含量。     

镍基合金镀层中镍的快速测定

本文采用原子吸收光谱法测定了含稀土的镍基合金镀层中的镍含量。其特点是灵敏度高,选择性好,数据准确可靠,方法简便快速,具有广泛的使用价值。本文研究建立了在弱酸性介质中,以特征波长232nm作测定波长,镍空心阴极灯为光源,用火焰原子化进行测定镀层中的镍含量。     

钢铁中微量镍测定方法的探讨

镍的测定方法很多,常用的有重量法、容量法,吸光光度法。对于钢铁中微量镍的测定只能采用吸光光变法,其使用范围0.01～0.03％,再低含量就无法测定。为了控制分析误差,往往绘制0.01～0.6％、0.6～1.5％、1.5～3.0％三种工作曲线,比较复杂。这里我们利用标准加入法的原理,测定钢铁中微量镍的含量,到目前为止尚未     

丁二酮肟分光光度法测定硫酸镍生产废水中的镍

本文将丁二酮肟分光光度法应用于硫酸镍生产废水中镍的测定。以过硫酸铵作氧化剂，丁二酮肟为显色剂，在波长的４６５ｎｍ处测定硫酸镍生产废水中的镍。     

丁二酮肟比色法测定高比重合金中镍含量

本采用丁二酮肟比色法测定高比重合金中镍含量的实验条件是：溶液在碱性介质中，在氧化剂存在下，镍与丁二酮肟生成可溶性红色络合物，然后进行比色测定。     

5—Br—PADAP一阶导数光度法同时测定钴和镍的研究

本文研究了５－Ｂｒ－ＰＡＤＡＰ与钴，镍反应的导数行为，利用一阶导数光度法同时测定钴和镍的新方法。用所建立的方法对化学试剂中的钴和镍的含量进行了同时测定，结果令人满意。     

基于尿素中镍含量的测定探析

通常尿素中镍的含量大约在2×10^-6,用分光光度法测定镍的含量,准确率高,而且分析过程比较简单,测定速度也比较快,检测出的镍含量精密度好,这种检测方法完全可以满足工业生产需求。本文针对尿素中镍含量的测定展开探讨,分析镍元素测定过程中形成误差的原因及镍元素测定的注意事项。     

5－Br－PADAP一阶导数光度法同时测定钴和镍的研究

本文研究了５－Ｂｒ－ＰＡＤＡＰ与钴、镍反应的导数行为，利用一阶导数光度法同时测定钴和镍的新方法。用所建立的方法对化学试剂中的钴和镍的含量进行了同时测定，结果令人满意。     

黑镍镀液分析方法研究

介绍了使用氨气敏电极通过电位分析方法准确地测定黑镍镀液中的NK^ 4含量，进而测定硫酸镍铵、硫酸镍的含量解决了常规容量分析法无法测定合有硫酸镍铵、硫酸镍的黑镍镀涣成分含量的问题。方法简便易行，准确度高。     

溶胶-凝胶法制备油脂加氢催化剂的研究

采用溶胶－凝胶法，制备了可用于食用油脂加氢的单元镍催化剂，研究了催化剂制备方法对催化剂镍含量的影响及镍含量的变化对活性的影响。研究表明：镍含量最佳值在20％左右，催化剂的活性随镍含量增加而提高，采用乙醇代替水洗可有效提高催化剂的镍含量和催化活性。     

纳米Ni/Fe对水中硝基苯的催化还原特性

采用自制的纳米Ni/Fe对水中硝基苯进行催化还原处理。探讨了硝基苯的还原降解途径,考察了溶液pH、纳米Ni/Fe用量和Ni含量对还原效果的影响。结果表明,纳米Ni/Fe对水中硝基苯的去除是纳米Ni/Fe的吸附作用和还原作用的协同作用的结果,两者对硝基苯去除率的贡献分别为33.7%和66.3%。纳米Ni/Fe可将硝基苯还原为苯胺和中间产物亚硝基苯,亚硝基苯进一步被还原为最终产物苯胺。还原产物苯胺的生成率随溶液pH的升高而降低;随纳米Ni/Fe用量的增加而升高;Ni含量的适当增大有利于硝基苯还原为苯胺,但Ni含量过高时会导致苯胺生成率降低,适宜的Ni含量为1.85%。纳米Ni/Fe对硝基苯的催化还原过程遵循一级反应动力学规律,反应速率常数为0.0226 min-1。     

Synthesis of flake-like graphene from nickel-coated polyacrylonitrile polymer

Graphene can be synthesized from polyacrylonitrile (PAN) polymer through pyrolysis. A metal catalyst such as nickel (Ni) is required for the conversion of the polymer to graphene. The metal catalysts can be placed either atop or underneath the polymer precursor. We observed that spatially non-uniform and disconnected graphene was fabricated when PAN film coated with a Ni layer was pyrolyzed, resulting in flake-like graphene. Formation of the flake-like graphene is attributed to the dewetting of the Ni layer coated on the PAN film. Dewetting phenomenon can be reduced by decreasing the pyrolysis temperature, and hence, more uniform graphene could be prepared. The effects of Ni coating thickness and the pyrolysis temperature on the fabricated graphene have been experimentally analyzed.     

缓释镍陶粒对废水厌氧处理的影响

以粉煤灰、水泥、石灰、石膏为主要原料,以CaCl2、Na2SO4、Na3PO4为复合添加剂,在制备陶粒过程中加入吸附Ni2+后的硅藻土,采用蒸气养护法制备出缓慢释放微量Ni2+的生物陶粒,并研究其对废水厌氧处理的影响。实验结果表明,陶粒对Ni2+的释放量与陶粒负载Ni2+质量、陶粒蒸养时间有关,陶粒释放平衡时间为9 d,起到了很好的缓释效果;通过在厌氧生物反应器中空白对照组与添加缓释Ni2+陶粒组的对比实验表明,添加缓释Ni2+反应器的COD去除率最高达到89.8%,比空白对照组高出23.6%,缓释陶粒释放出的Ni2+离子能够被微生物很好的吸收利用,提高废水厌氧处理效果,而不会造成水质的污染。     

电解回收镀镍废水中镍的研究

首次提出了从镀镍废水中电渗析电解回收金属镍的方法，并对电解回收过程中的影响因素进行了讨论，利用此法将含镍离子１ｇ／ｌ左右的镀镍废水处理至５０ｍｇ／Ｌ左右，电流效率可达６０％以上。     

Study on the blackening phenomenon of leaded glass during microgroove molding using nickel phosphorous mold

Precision glass molding (PGM) is a recently developed method to fabricate glass microgroove components. Lead glass is commonly used as an optical material due to its high refractive index and low transition temperature. A nickel-phosphorous (Ni–P) plated mold is traditionally employed in the PGM process for microstructures optics. However, leaded glass is subject to color change and can blacken during the PGM process, reducing the light transmittance of microgrooves. In this paper, an equation for the redox reaction between Ni and Pb is proposed, which is based on the diffusion of inner Ni atoms to the surface of the mold and the standard electrode potential of the Pb ions in leaded glass. A viscoelastic constitutive model of the glass is established to simulate the compression stress distribution during molding. Finally, the effects of molding pressure, molding temperature, and mold material on glass blackening are studied. The results show that the blackening of leaded glass is caused by Pb enriching the surface. The rise in molding stress and temperature increases the deformation of Ni–P plating, which promotes the diffusion of Ni atoms. By adding a titanium incorporated diamond-like carbon (Ti-DLC) coating, the deformation of the Ni–P plating during molding is suppressed, and the diffusion of Ni atoms can be prevented. In this way, the blackening of leaded glass can be prevented.     

一种镍离子浓度自动检测方法

给出一种以单片机为核心的化学镀镍液中镍离子浓度自动检测电路,以实现利用光电比色法对镍离子浓度的自动分析,对其硬件构成、软件设计、可靠性等有关问题进行了详细介绍。     

Bound-state Ni species — a superior form in Ni-based catalyst for CH4/CO2 reforming

The effects of nickel loading, calcination temperature, support, and basic additives on Ni-based catalyst structure and reactivity for CH₄ reforming with CO₂ were investigated. The results show that the structure of the nickel active phase strongly depends on the interactions of the metal and the support, which are related to the support properties, the additives and the preparation conditions. “Free” Ni species can be formed when the interaction is weak and their mobility makes them easily deactivated by coking and sintering. The effect of strong metal-support interaction (SMSI effect) is different for various supports. The formation of solid solution of Ni–Mg–O₂ and the blocking of TiO_x by the partially reduced TiO₂ can both decrease the availability of Ni active sites in Ni/MgO and Ni/TiO₂. The spinel NiAl₂O₄ formed in Ni/γ-Al₂O₃ might be responsible for its high activity and resistance to coking and sintering because it can produce a highly dispersed active phase and a large active surface area as bound-state Ni species when the catalyst is prepared at high calcined temperatures or with low nickel loading. The addition of La₂O₃ or MgO as alumina modifiers can also be beneficial for the performance of the Ni/γ-Al₂O₃ catalyst.     

Synthesis and Growth Mechanism of Ni Nanotubes and Nanowires

Highly ordered Ni nanotube and nanowire arrays were fabricated via electrodeposition. The Ni microstructures and the process of the formation were investigated using conventional and high-resolution transmission electron microscope. Herein, we demonstrated the systematic fabrication of Ni nanotube and nanowire arrays and proposed an original growth mechanism. With the different deposition time, nanotubes or nanowires can be obtained. Tubular nanostructures can be obtained at short time, while nanowires take longer time to form. This formation mechanism is applicable to design and synthesize other metal nanostructures and even compound nanostuctures via template-based electrodeposition.     

A Novel Approach to the Preparation of a Highly Crystallized BaTiO3 Layer on Ni Nanoparticles

A novel chemical approach is proposed to facilitate the crystallization of the BaTiO₃ coating layer on Ni nanoparticles for multilayer ceramic capacitors. Based on the chemical equilibrium principle, the polycrystalline coating layer can be obtained at atmospheric pressure and at a relatively low temperature by a one‐step reaction. The details of the coating process of the Ni nanoparticles are clearly discussed. The coating is uniform, dense, and well crystallized, and can protect the Ni from oxidation and also shift the starting point of Ni densification to a higher temperature, reducing differential shrinkage issues in the co‐firing.