Papers by Keyword: Complex

Abstract: Superoxide dismutase (SOD) is an Mn-containing enzyme that catalyzes the conversion of superoxide (O₂^•−) into O₂ and H₂O₂. To develop a small, non-protein Mn-containing SOD mimic, an [Mn(salen)Cl] complex was synthesized from MnCl₂.4H₂O and H₂salen. The product yielded 75-90% reddish dark brown crystals indicative of the presence of manganese(III) metal ions. An elemental analysis showed that the compound contained: C = 48.36%; H = 4.34%; and N = 7.13%. Infrared spectra of this compound showed peaks at: υ(OH)=3426 (medium), υ(C=N)=1634 (very high), υ(CO)=1292 (high). An ESI-MS analysis (m/z) showed the presence of ionic species from the complex including (salen)(H⁺) = 269.0 and [Mn(salen)]⁺ = 320.9. Conductivity measurements revealed that the compound is neutral with a molar conductivity of 0.17 mS. Its magnetic moment of 5.2 BM was obtained from a magnetic susceptibility balance measurement, showing that the compound is paramagnetic. The SOD activity of this compound was given by IC₅₀ = 2.5 ± 0.3 µM in a non-enzymatic riboflavin photoreduction in vitro test.

Abstract: The inclusion complex of β-cyclodextrin (β-CD) and dibutyl phosphite (T304) was prepared by trituration. The tribological properties of the complex with different concentrations were investigated by a four-ball tester in the solution of polyethylene glycol-600 (PEG-600). The tribological test results showed that the complex exhibited better anti-friction and anti-wear properties than β-CD under different loads, and it was noted that the tribo-system showed the least friction coefficient when the concentration of the complex was 0.9%. It was proposed that the complex was decomposed into various molecular fragments and the T304 molecules were released under the friction condition. The XPS analytical results on the worn surfaces revealed that phosphide film formed by the released T304 played a major role and the iron alkoxide and carbon deposition films formed by the β-CD fragments had better anti-friction effect on the phosphide film surface. The interactions of different films resulted in the formation of a mixed boundary lubrication film.

Abstract: The TiO₂ complex samples were produced through sol-gel method, using Ti (OC₄H₉)₄, rice husk (RH) and methenamine as the reactants. Some property analyses were conducted, including X-ray diffraction (XRD), Brunauer-Emmet-Teller (BET), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and photocatalytic experiments in the condition of visible-light. The results showed that the size of crystal was limited with the addition of RH in the complex of N/RH/TiO₂ samples. The particles of TiO₂ were dispersed on the surface of rice husk ash, the skeleton of RH after burning. It can inhibit the phenomenon of agglomerate. The ability of both adsorption and photocatalytie activity of complex samples increased as the surface area increased. Doping N into RH/TiO₂ samples can decrease the forming time, inhibit the transformation of crystal from anatase to rutile to some extent, improve the bond of Ti-O-Si to form and make the absorption spectrum move to the red light part. The complex samples exhibited a certain photocatalytic activity under the visible light region. The reaction rate of visible light photodegradation process arrived 0.0143 min^-1, meeting with the first-order reaction kinetics.

Abstract: The electrochemical behavior of Fe-Cr-Mo codeposition was investigated by using linear scanning. The deposition potential of Fe2+ shifted negatively after adding glycine and additive W, while the deposition potential of Cr3+ had no obvious change, then the purpose of codeposition was achieved. Induced codeposition occurred after adding molybdate into the solution, at last alloy coating of good appearance was obtained.

Abstract: The optimization of complex, electrical and electrochemical erosion processing focuses on improving quality and reducing energy consumption while processing, considering the actual growing of the energy crisis. The technological process is considered to be a system and its components are considered to be subsystems. This paper contains an analysis of the optimization methods that can be applied to dimensional processing using complex, electrical and electrochemical erosion and states the optimization directions and methods that can be used in order to increase the performance of some of the components of the technological process (the subsystems) or of the whole process (the system).

Abstract: 4-(N,N-dibutylaminomethyl) morpholine salt (DBM) was synthesized with morpholine，di-n-butylamine，paraformaldehyde under acid condition and characterized by IR. According to corrosion reason and characteristic of blast furnace gas pipeline, DBM, cyclohexylamine, ethanolamine, propargyl alcohol, etc were chosen as composition of compound corrosion inhibitor formulations, and their corrosion inhibition performance were evaluated by weight-loss method and electrochemical method. The results showed that the yield of DBM was 93.95% when mole ratio of morpholine, di-n-butylamine and paraformaldehyde was 1:1.2:1.2 and reaction temperature was 60 °C, reaction time was 5 h. The compound corrosion inhibitor containing DBM exhibited good inhibitory effect to cathode electrochemical process to the corrosion of A3 carbon steel cathode electrochemical process and the corrosion inhibition efficiency was 98.46%.

Abstract: Polyamide 6 (PA6) gels were prepared by dissolving PA6 powder with relative viscosity 25.85 in formic acid using CaCl₂ as complex agent. Concentration of the polymer was 18 (w/v) %. And then, polyamide 6 (PA6) fibers were obtained through gel-spinning. In this study, the effects of solvent content on fiber structure and properties were investigated. The results showed that with the increasing of solvent content, significant changes occurred in the crystalline structure and thermal property of fibers. The optimum solvent content of fibers with the highest mechanical property in this study was 9.4%.

Abstract: This paper built two kinds of networks:co-author network and competition network and set up a system of influence measurement to determine who is most influential in the network.To evaluate the influence of co-authors, this paper introduced three norms: degree centrality, closeness centrality and betweenness centrality. Then, entropy value method was applied to get the relative weight of norms and establish co-author influence measurement model by the weighted sum of the three norms as influence marks. Meanwhile, the number of times players competed with each other among 10 tennis players in nearly 20 years was chosen to build our network. Because same as the co-author network, the competition network is undirected, we employ same algorithm to rank tennis players and analyze the first three players' competition relationship.

Abstract: Cyclohexylamine, morphine, ethanolamine, propiolic alcohol, seventeen alkenyl amide ethyl imidazoline, water depolymerization malaya acid anhydride, etc were chosen as the raw material of corrosion scale inhibitor in view of corrosion scaling reason and characteristic of blast furnace top gas pressure recovery turbine unit. The optimized formula of corrosion inhibitor have been obtained through orthogonal experiment. Corrosion and scale inhibitor performance were evaluated respectively by static weight-loss method, dynamic weight-loss method and calcium carbonate deposition. The results show that when these components are reasonable distributed, the corrosion effect is satisfied. When water depolymerization malaya acid anhydride is combined with the corrosion inhibitor, the corrosion and scale inhibition efficiency of composite inhibitor are more than 90%. Simulation blast furnace gas is adopted in dynamic simulation experiment, the corrosion inhibition efficiency is over 92%.

Abstract: The results of research of kinetic of oxidations of phenol by oxygen at presence of nitrogen oxides and complexes of cobalt fixed on polyacrylic acid at 333К are presented in the article. It is established, that at presence of complexes of cobalt fixed on PAA and oxides of nitrogen it is possible to spend oxidation of phenol in soft conditions. Fixation of mononuclear complexes on polyacrylic acid promotes destruction of an aromatic ring, getting of aliphatic aldehydes and ketones while at presence of binuclear complexes of cobalt fixed on PAA process of oxidation comes to an end with formation benzoquinone. The given system works stably.