Mu M.,Tianjin University |
Chen L.,Tianjin University |
Wang S.,Lanzhou Industry Research Institute
Journal of Porous Materials | Year: 2015
Tungstophosphoric acid supported on TiO2 (TPA/TiO2) and iron modified tungstophosphoric acid supported on TiO2 (Fe0.5TPA/TiO2 and FeTPA/TiO2) were prepared and examined for Friedel–Crafts acylation reactions. The obtained results indicated that FeTPA/TiO2 exhibited excellent catalytic performance on the acylation of m-xylene with benzoyl chloride, but inferior results were obtained in the acylation of anisole with acetic anhydride. However, TPA/TiO2 displayed better catalytic activity than others in the later reaction. All the catalysts were characterized by XRD, FT-IR, NH3-TPD, Py-IR and TGA. The obtained results demonstrated that the Lewis acidity of catalysts presented a significant influence on the reaction with benzoyl chloride as acylating agent while the total acidity of catalysts was more important with acetic anhydride as acylating agent. Finally, the reaction mechanisms with two acylating agents over the above catalysts were discussed. © 2015, Springer Science+Business Media New York.
Wang B.,Tianjin University |
Fang W.,Tianjin University |
Si L.,Tianjin University |
Li Y.,Tianjin University |
And 3 more authors.
ACS Sustainable Chemistry and Engineering | Year: 2015
The synthesis of 2-(2′-hydroxy-5′-methylphenyl)benzotriazole from 2-nitro-2′-hydroxy-5′-methylazobenzene over Pd/γ-Al2O3 in a fixed-bed reactor was investigated. Pd/γ-Al2O3 catalysts were prepared by two methods and characterized by XRD, TEM, H2-TPR, and N2 adsorption-desorption. Employed in the above reaction, the palladium catalyst impregnated in hydrochloric acid exhibited much better catalytic performance than that impregnated in ammonia-water, which was possibly attributed to the better dispersion of palladium crystals on γ-Al2O3. This result demonstrated that the preparation process of the catalyst was very important. Furthermore, the reaction parameters were optimized. Under the optimized conditions (toluene, NAB/triethylamine molar ratio 1:2, 60 °C, 2.5 MPa hydrogen pressure, 0.23 h-1 liquid hourly space velocity), about 90% yield of 2-(2′-hydroxy-5′-methylphenyl)benzotriazole was obtained. Finally, the time on stream performance of the catalyst was evaluated, and the reaction could proceed effectively over 200 h without deactivation of the catalyst. © 2015 American Chemical Society.
Wang S.,Lanzhou Industry Research Institute
Chemistry Bulletin / Huaxue Tongbao | Year: 2012
Cefcapene pivoxil is one of the important kinds of the fourth generation Cephalosporin antibiotics. It processes high stability, excellent antibacterial capacity and low toxicity. The synthesis of cefcapene pivoxil has been intensively studied. In this paper, four synthetic routes of it were tried with 7ACA and (Z)-2-[(2-tert-butoxycarbonylamino) thiazol-5-yl) pent-2-enoic acid as the starting material. Finally cefcapene pivoxil was successfully obtained in the total yield of 14% by Route IV.
Zhang S.,Lanzhou Industry Research Institute |
Gao S.,Gansu College of Traditional Chinese Medicine |
Gao G.,Lanzhou Industry Research Institute
Applied Biochemistry and Biotechnology | Year: 2010
A study of the cross-linking of β-galactosidase on magnetic beads is reported here. The magnetic beads were prepared from artemisia seed gum, chitosan, and magnetic fluid in the presence of a cross-linking regent (i.e., glutaraldehyde). The reactive aldehyde groups of the magnetic beads allowed the reaction of the amino groups of the enzymes. The animated magnetic beads were used for the covalent immobilization of β-galactosidase. The effect of various preparation conditions on the activity of the immobilized β-galactosidase, such as immobilizing time, amount of enzyme, and the concentration of glutaraldehyde, were investigated. The influence of pH and temperature on the activity and the stability of the enzyme, both free and immobilized, have been studied. And o-nitrophenyl-β-d-galactopyranoside (ONPG) was chosen as a substrate. The β-galactosidase immobilized on the magnetic beads resulted in an increase in enzyme stability. Optimum operational temperature for immobilized enzyme was 10 °C higher than that of free enzyme and was significantly broader. © 2009 Humana Press.
Yang H.,Chinese Institute of Scientific and Technical Information |
Yin T.,Lanzhou University |
Zhang S.,Lanzhou Industry Research Institute
International Journal of Food Properties | Year: 2015
A new polysaccharide (MEP-1) was isolated from fruit body of wide Morchella esculenta (L.) Pers with a stepwise procedure of hot water extraction, removal of the protein, dialysis against water, DEAE-Cellulose A52 and Sephadex G-100 columns. Physicochemical properties of the polysaccharide was determined by chemical methods, high-performance gel permeation chromatography, high performance liquid chromatography, paper chromatography, ultraviolet spectrum, and infrared spectrometry. The polysaccharides were primarily polymers of glucose, mannose, galactose, and arabinose. The average molecular mass was 43625 Da. © Copyright 2015 Taylor & Francis Group, LLC.
Zhang S.T.,Lanzhou Industry Research Institute
Plastics, Rubber and Composites | Year: 2012
Water swellable rubber was prepared by blending styrene butadiene rubber as a matrix, crosslinked poly sodium polyacrylate (PAANa) as a high absorbent water resin, copolymer styrene maleic anhydride as a compatibiliser and polyethylene glycol as an absorbent accelerant. The preparation process was described. The effects of various preparation conditions, such as amount of sulphur, ratio of silicon dioxide to nanocalcium carbonate, amount of PAANa and amount of compatibiliser, on its water absorbency and mechanical properties were investigated by orthogonal tests. The optimal reaction conditions were 2 portion (phr) sulphur, 28 : 12 silicon dioxide/nanocalcium carbonate, 60 phr PAANa and 5 phr compatibiliser. Furthermore, the vulcanisation property of the rubber was measured. © 2012 Institute of Materials, Minerals and Mining.
Ma W.-L.,CAS Lanzhou Institute of Chemical Physics |
Lu L.,Lanzhou Industry Research Institute |
Guo H.-R.,Lanzhou Industry Research Institute |
Wang J.-B.,CAS Lanzhou Institute of Chemical Physics |
And 3 more authors.
Mocaxue Xuebao/Tribology | Year: 2013
The Fe-Mo-Graphite (FM) and Fe-Mo-Ni-Graphite (FMN) composites were fabricated by P/M technology. The microstructure, component and the tribological behavior of these composites at room temperature, 320°C and 450°C were investigated. The results indicate that both kinds of composites were mainly composed of ferrites, pearlite, Fe3Mo, Mo2C, Fe2MoC carbides, and small amount of compacted graphite. The content of pearlites in FMN was less than that in FM. It is suggested that the addition of Ni element affect the formation and growth of the pearlite. At room temperature, the surface layer rich in graphite in sliding contact was contributed to the low friction of these composites. At elevated temperature, graphite and Fe oxides on the surface of counterparts, such as Fe2O3, Fe3O4 and FeO·Cr2O3 played the key role on decreasing friction and reducing wear.
PubMed | Lanzhou Industry Research Institute
Type: Journal Article | Journal: Applied biochemistry and biotechnology | Year: 2010
A study of the cross-linking of beta-galactosidase on magnetic beads is reported here. The magnetic beads were prepared from artemisia seed gum, chitosan, and magnetic fluid in the presence of a cross-linking regent (i.e., glutaraldehyde). The reactive aldehyde groups of the magnetic beads allowed the reaction of the amino groups of the enzymes. The animated magnetic beads were used for the covalent immobilization of beta-galactosidase. The effect of various preparation conditions on the activity of the immobilized beta-galactosidase, such as immobilizing time, amount of enzyme, and the concentration of glutaraldehyde, were investigated. The influence of pH and temperature on the activity and the stability of the enzyme, both free and immobilized, have been studied. And o-nitrophenyl-beta-D: -galactopyranoside (ONPG) was chosen as a substrate. The beta-galactosidase immobilized on the magnetic beads resulted in an increase in enzyme stability. Optimum operational temperature for immobilized enzyme was 10 degrees Celsius higher than that of free enzyme and was significantly broader.