نتایج جستجو برای: سیستم ni
تعداد نتایج: 126467 فیلتر نتایج به سال:
Hydrogenolysis and dehydrogenation of propane were studied over model nickel–gold catalysts. The supported model Ni–Au catalysts were prepared by depositing Ni and Au onto a planar silica film. Infrared reflection absorption spectroscopic data showed that isolated Ni sites appeared and became dominant on the surface with the addition of Au to Ni. For the conversion of propane in the presence of...
The Ramsey number for a graph G versus a graph H, denoted by R(G,H), is the smallest positive integer n such that for any graph F of order n, either F contains G as a subgraph or F contains H as a subgraph. In this paper, we investigate the Ramsey numbers for union of stars versus small cycle and small wheel. We show that if ni ≥ 3 for i = 1, 2, . . . , k and ni ≥ ni+1 ≥ √ ni − 2, then R( ∪k i=...
We examined the influence of macronutrient (nitrate and phosphate) additions on Ni uptake by phytoplankton (Prorocentrum donghaiense and Skeletonema costatum) and its subsequent transfer to marine copepods (Calanus sinicus and Labidocera euchaeta). Ni uptake by phytoplankton after 24h of exposure was markedly dependent on nutrient conditions, with a higher nutrient quota facilitating Ni accumul...
The title compound, [Ni(C(11)H(10)N(2)O(2))(2)](NO(3))(2), consists of an Ni(II) atom coordinated by two tridentate chelating di-2-pyridylmethane-diol [(2-py)(2)C(OH)(2)] ligands. The Ni(II) atom is located on an inversion center. The geometry around the Ni(II) atom is distorted octa-hedral. The gem-diol (2-py)(2)C(OH)(2) ligand adopts the coordination mode η(1):η(1):η(1). The Ni-N and Ni-O bon...
Methanol oxidation catalysts comprising an outer Pt-shell with an inner Ni-core supported on carbon, (Pt-Ni/C), were prepared with either crystalline or amorphous Ni core structures. Structural comparisons of the two forms of catalyst were made using transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and methanol oxidation activity compar...
Photolysis of [Ni(II)(μ-Cl)Cl(IPr)](2) (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) activates the Ni-Cl bonds to furnish [Ni(I)(μ-Cl)(IPr)](2). Consistent with this photochemistry, a TD-DFT calculation for square planar Ni(ii) centre reveals that light excitation leads to the population of orbitals with σ*(Ni-Cl) character.
[Ni(L(1))Fe((t)BuNC)4](PF6)2 is a robust Ni(II)Fe(II) complex that undergoes a reversible one-electron reduction. Spectroscopic and theoretical studies show that [Ni(L(1))Fe((t)BuNC)4](+) is an unprecedented Ni(I)Fe(II) species that reproduces the electronic configuration of the Ni-L state of the [NiFe] hydrogenases.
For SOFCs to be main means of power generation, they should be able to exploit wide variety of fuels. Among Ni-cermets, Ni-YSZ is the state-of-the-art materials for the anode in SOFC which is the fuel electrode. But sulphur impurity present in different gaseous fuels (e.g Biogas), depending on its concentration, is highly poisonous to the stability and electrochemical performance of the Ni cata...
High concentrations of nickel (Ni) are harmful to humans and animals. Ni targets a number of organs and produces multiple toxic effects. Apoptosis is important in Ni-induced toxicity of the kidneys, liver, nerves, and immune system. Apoptotic pathways mediated by reactive oxygen species (ROS), mitochondria, endoplasmic reticulum (ER), Fas, and c-Myc participate in Ni-induced cell apoptosis. How...
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