Papers by Keyword: Activity

Abstract: FCC gasoline fraction (75~120°C) is feedstock, Ethyl silicate (TEOS) or γ-aminopropyl triethoxysilane were used as the silicon source respectively, aromatization were examined on the fixed-bed reactor. The catalyst activity and stability are improved when SiO2 depositions are 2% and 10%, respectively.

Abstract: In the treatment of methyl orange simulation printing and dyeing wastewater by catalytic wet air oxidation method, the Ru series catalysts were prepared with the equal amount impregnation method. The catalyst activity and stability were characterized by the decolorization rate of the water samples, and the eluted metal ion concentration from the catalyst of the water samples. XRD, SEM, FT-IR were used to characterize the catalysts. The results showed that: when active allocation ratio of the catalyst was Ru:Cu:Fe:Ce:La = 1:0.5:0.5:0.5:0.5, the degradation rate of methyl orange could reach up to 98.5%. And the concentration of each metal component eluted lower after the reaction, while its activity and stability were relatively high.The active component of 1wt% Ru catalyst mainly existed as the form of γ-Al₂O₃, RuO₂, La₂O₃, La₂CuO₄ and CeO₂. The surface of catalyst was relatively flat and flaky. The Ru catalyst appeared strong infrared absorption in the vicinity of 1070 cm^-1, 1650 cm^-1 and 3450 cm^-1.

Abstract: The optimum extraction condition of water-soluble asparagus powder through water boiling method is to extract it twice, in the first extraction, 8% is set as the solid-liquid ratio, 15 minutes is set as the soak time and 40 minutes is set as the boiling time; in the second extraction, 10% is set as the solid-liquid ratio, 40 minutes is set as the boiling time. Under this condition, the dry yield rate is 33.98%, and the total active substance yield rate is 10.34% (including flavones yield rate of 1.0%, saponin yield rate of 5.99%, and polysaccharide yield rate of 3.35%). Water-soluble asparagus powder has good removal effects on hydroxyl radicals, superoxide anion free radicals, and DPPH free radicals. The water-soluble asparagus powders made from the raw material in different pick-time have different removal effects on DPPH free radicals, and the asparagus powder made from asparagus picked in August, September, and October is better.The best is to read these instructions and follow the outline of this text.

Abstract: The property of raw kaolinite-coal-gangue is very stable, and reactivity of kaolinite-coal-gangue is enhanced by mechanical force. The SEM, XRD and IR were used to analyze mechanochemical changes during kaolinite-type-coal gangue grinding. The results showed that mechanical force plays a dominant role in the enhanced reactivity, by inducing dehydration reactions the lattice OH grouping decreased with the extension of grinding time. The separation of tetrahedral and octahedral layers combined with the increasing disorder of the kaolinite crystal structure, resulting in kaolinite-type-coal gangue particles become "loose" aggregates. Moreover, due to destroy to tight Si-O and Al-O bond, the mechanical force increases the solubility of SiO2 and Al2O3, which enhanced the reactivity of coal gangue.

Abstract: Hydration activity of silica fume(SF) and its effect on the structure of C-S-H gel in silica fume-cement (SFC)pastes was studied by FTIR and 29Si MAS NMR combined with deconvoluton technique, respectively. The experimental results indicate that the cement of 48% and the SF of 41% can react in the paste with SF replacement for cement was 10% by weight and the average chain length (ACL) of SiO4 and/or AlO4 tetrahedra in C-S-H was 3.0 at 3d. At 120d, the cement of 65% and the SF of 96% could react, and the ACL of C-S-H was 3.7, which was higher than that in the plain cement paste (ACL was 3.1). In the highly alkaline environment of the cement paste, pozzolanic reaction of silica fume can potentially occur in two ways, the monosilicate formed after the structure of silica fume were broken can combine with Ca cations to form C-S-H directly. Moreover, these chemical species can also connect C-S-H dimers into highly polymerized C-S-H and increase the ACL of C-S-H.

Abstract: This paper reports the effect of alkali precipitating agents, i.e. KOH and NaOH, on activity and stability of Cu-Mn based catalysts for the water gas shift (WGS) reaction. Structural and texture characteristics of the catalysts were characterized by low temperature N2 adsorption, X-Ray Diffraction (XRD) and TPR techniques. The XRD and low temperature N2 adsorption results showed the two types of precipitators produced different Cu-Mn phases during precipitation and drying. The KOH precipitator resulted in partial precipitation of copper ion and formation of hydrate basic copper sulfate, Cu₄SO₄(OH)₆•H₂O after drying; while the NaOH precipitator led to a completed precipitation of Cu ion and formation of relatively stable Cu₂₊₁O and Mn₃O₄ crystals after drying. These phases formed after precipitation by the KOH and NaOH, however, experienced the same phase change during calcination and activation, namely, they first changed to Cu_1.5Mn_1.5O₄ in calcination followed by the formation of microcrystalline Cu and MnO phases during activation. The Cu-Mn WGS catalysts prepared by the NaOH was found to have larger surface area and more content of Cu and MnO phases after activation, which might be the reasons of higher activity and better stability of the Cu-Mn catalyst.

Abstract: Sixteen 3-arylurea-5-fluoroindolin-2-one derivatives were designed according to the principle of fragment based drug discovery and synthesized with 5-fluoroisatin as the starting material. The obtained structures were identified by 1H NMR, MS and elemental analysis. In vitro evaluation of antitumor bioactivity was performed by MTT method. Most of synthesized compounds showed antitumor activities, especially, activities of 6a, 6h, and 6j in tumor inhibition were better than others.

Abstract: The effects of Cu/Mn ratio on the activity and stability of Cu-Mn catalysts for the water-gas shift reaction (WGSR) were investigated. Activity tests showed that the Cu-Mn catalyst while the ration of Cu to Mn is 1:1 displayed higher activity and better stability than that of others catalysts. The BET , XRD and TPR results revealed that the Cu-Mn catalyst while the ration of Cu to Mn is 1:1 led to higher surface area, a more stable catalyst structure and suitable reduction performance, in turn leading to better catalytic behavior for the Cu-Mn catalyst.

Abstract: Nine 5-fluoroindolin-2-one derivatives with urea linkage were designed and synthesized. The obtained structures were identified by 1H NMR, MS and elemental analysis. In vitro evaluation of antitumor bioactivity was performed by MTT method. Most of synthesized compounds showed antitumor activities, especially, compounds 6e and 6f, which were better than or equal to the antitumor activity of positive control.

Abstract: The effects of alkali charge on the activity and stability of copper-based mixed oxides catalyst for the water-gas shift reaction (WGSR) were investigated. Activity tests showed that the copper-based mixed oxides catalyst while the 2[NaOH]/[Cu²⁺+Mn²⁺] is above 1.2 displayed higher activity and better stability than that of others catalysts. The BET , XRD and TPR results revealed that the Cu-Mn catalyst while the 2[NaOH]/[Cu²⁺+Mn²⁺] is above 1.2 led to higher surface area, a more stable catalyst structure and suitable reduction performance, in turn leading to better catalytic behavior for the Cu-Mn catalyst.