Microcapsules containing oil drag-reducing polymer particles were prepared by melting-scattering and condensing of polyethylene wax,in-situ polymerization of urea and formaldehyde,and interfacial polymerization of sty...Microcapsules containing oil drag-reducing polymer particles were prepared by melting-scattering and condensing of polyethylene wax,in-situ polymerization of urea and formaldehyde,and interfacial polymerization of styrene respectively.The related processes were studied by a molecular dynamics simulation method,and molecular design of microcapsule isolation agent was carried out on the basis of the simulation.The technologies for preparing microencapsulated oil drag-reducing polymer particles were compared and the circulation drag reducing efficiency of the microencapsulated polymer particles was evaluated based on the characterization results and their dissolution properties.Molecular design of a microcapsule isolation agent suggests that a-olefin polymer particles can be stably dispersed in water by using long-chain alkyl sodium salt surfactant which can prevent the agglomeration ofα-olefin polymer particles.The results of simulation of the adsorption process shows that the amount of alkyl sodium salt surfactant can directly affect the stability of microencapsulatedα-olefin polymer particles, and there must be a minimum critical amount of it.After characterization of the morphology by Scanning Electron Microscopy(SEM) and comparison of the static pressure stability,especially the conditions of reaction and technological control of microcapsules with different shell materials,microencapsulation of a-olefin polymer particles with poly-(urea-formaldehyde) as shell material was selected as the optimum scheme,because it can react under mild conditions and its technological process can be controlled in a large range.The relationship of drag reducing rate and dissolving time of microcapsules showed that the formation of microcapsules did not affect the maximum drag reducing rate,and the drag reducing rate of each sample can reach about 35%along with the dissolving time,i.e.microencapsulation did not affect the drag reducing property ofα-olefin polymer.展开更多
The present study was aimed to assess the ability of Bacillus sp.JDM-2-1 and Staphylococcus capitis to reduce hexavalent chromium into its trivalent form.Bacillus sp.JDM-2-1 could tolerate Cr(Ⅵ)(4800 μg/mL) and ...The present study was aimed to assess the ability of Bacillus sp.JDM-2-1 and Staphylococcus capitis to reduce hexavalent chromium into its trivalent form.Bacillus sp.JDM-2-1 could tolerate Cr(Ⅵ)(4800 μg/mL) and S.capitis could tolerate Cr(Ⅵ)(2800 μg/mL).Both organisms were able to resist Cd^2+(50 μg/mL),Cu^2+(200 μg/mL),Pb^2+(800 μg/mL),Hg^2+(50 μg/mL) and Ni2+(4000 μg/mL).S.capitis resisted Zn^2+ at 700 μg/mL while Bacillus sp.JDM-2-1 only showed resistance up to 50 μg/mL.Bacillus sp.JDM-2-1 and S.capitis showed optimum growth at pH 6 and 7,respectively,while both bacteria showed optimum growth at 37°C.Bacillus sp.JDM-2-1 and S.capitis could reduce 85% and 81% of hexavalent chromium from the medium after 96 h and were also capable of reducing hexavalent chromium 86% and 89%,respectively,from the industrial effuents after 144 h.Cell free extracts of Bacillus sp.JDM-2-1 and S.capitis showed reduction of 83% and 70% at concentration of 10 μg Cr(Ⅵ)/mL,respectively.The presence of an induced protein having molecular weight around 25 kDa in the presence of chromium points out a possible role of this protein in chromium reduction.The bacterial isolates can be exploited for the bioremediation of hexavalent chromium containing wastes,since they seem to have a potential to reduce the toxic hexavalent form to its nontoxic trivalent form.展开更多
A novel thermoregulated phosphine ligand PhP(CHCHO)CH(n=22) was synthesized and used for the Rh-catalyzed hydroformylation of mixed Colefins in aqueous/organic biphasic system.Under the optimized conditions,pressure =...A novel thermoregulated phosphine ligand PhP(CHCHO)CH(n=22) was synthesized and used for the Rh-catalyzed hydroformylation of mixed Colefins in aqueous/organic biphasic system.Under the optimized conditions,pressure =5 MPa (H:CO=1:1),phosphine/Rh =13(molar ratio),reaction time =6 h and temperature =130℃,the conversion of Colefins and the yield of aldehyde are 99%and 94%,respectively.The catalyst retained in aqueous phase can be easily separated from the product-containing organic phase by simple phase separation and the catalytic activity remains almost constant after four consecutive cycles.展开更多
Poly α-olefin,used as the drag reducing agent on the crude oil transportation,was analyzed by pyrolysis/gas chromatography-mass spectrometry(PY/GC-MS).Three polyolefin samples of polydecene,polyoctene and the copolym...Poly α-olefin,used as the drag reducing agent on the crude oil transportation,was analyzed by pyrolysis/gas chromatography-mass spectrometry(PY/GC-MS).Three polyolefin samples of polydecene,polyoctene and the copolymer of decene and octane,were analyzed.The samples were analyzed by increasing pyrolysis temperatures from 500 to 800 ℃.The result showed that the optimal pyrolysis temperature was 600 ℃.2-Methyl-decene and 2-methyl-pentadecene was selected as the characteristic pyrolysates for identification polydecene and polyoctene,respectively.The quantitative method of the copolymer was also discussed.Height peak of the characteristic pyrolysate was used to calculate the mass rate of the two monomers in the copolymers.The error of the method was-4.08%.展开更多
文摘Microcapsules containing oil drag-reducing polymer particles were prepared by melting-scattering and condensing of polyethylene wax,in-situ polymerization of urea and formaldehyde,and interfacial polymerization of styrene respectively.The related processes were studied by a molecular dynamics simulation method,and molecular design of microcapsule isolation agent was carried out on the basis of the simulation.The technologies for preparing microencapsulated oil drag-reducing polymer particles were compared and the circulation drag reducing efficiency of the microencapsulated polymer particles was evaluated based on the characterization results and their dissolution properties.Molecular design of a microcapsule isolation agent suggests that a-olefin polymer particles can be stably dispersed in water by using long-chain alkyl sodium salt surfactant which can prevent the agglomeration ofα-olefin polymer particles.The results of simulation of the adsorption process shows that the amount of alkyl sodium salt surfactant can directly affect the stability of microencapsulatedα-olefin polymer particles, and there must be a minimum critical amount of it.After characterization of the morphology by Scanning Electron Microscopy(SEM) and comparison of the static pressure stability,especially the conditions of reaction and technological control of microcapsules with different shell materials,microencapsulation of a-olefin polymer particles with poly-(urea-formaldehyde) as shell material was selected as the optimum scheme,because it can react under mild conditions and its technological process can be controlled in a large range.The relationship of drag reducing rate and dissolving time of microcapsules showed that the formation of microcapsules did not affect the maximum drag reducing rate,and the drag reducing rate of each sample can reach about 35%along with the dissolving time,i.e.microencapsulation did not affect the drag reducing property ofα-olefin polymer.
文摘The present study was aimed to assess the ability of Bacillus sp.JDM-2-1 and Staphylococcus capitis to reduce hexavalent chromium into its trivalent form.Bacillus sp.JDM-2-1 could tolerate Cr(Ⅵ)(4800 μg/mL) and S.capitis could tolerate Cr(Ⅵ)(2800 μg/mL).Both organisms were able to resist Cd^2+(50 μg/mL),Cu^2+(200 μg/mL),Pb^2+(800 μg/mL),Hg^2+(50 μg/mL) and Ni2+(4000 μg/mL).S.capitis resisted Zn^2+ at 700 μg/mL while Bacillus sp.JDM-2-1 only showed resistance up to 50 μg/mL.Bacillus sp.JDM-2-1 and S.capitis showed optimum growth at pH 6 and 7,respectively,while both bacteria showed optimum growth at 37°C.Bacillus sp.JDM-2-1 and S.capitis could reduce 85% and 81% of hexavalent chromium from the medium after 96 h and were also capable of reducing hexavalent chromium 86% and 89%,respectively,from the industrial effuents after 144 h.Cell free extracts of Bacillus sp.JDM-2-1 and S.capitis showed reduction of 83% and 70% at concentration of 10 μg Cr(Ⅵ)/mL,respectively.The presence of an induced protein having molecular weight around 25 kDa in the presence of chromium points out a possible role of this protein in chromium reduction.The bacterial isolates can be exploited for the bioremediation of hexavalent chromium containing wastes,since they seem to have a potential to reduce the toxic hexavalent form to its nontoxic trivalent form.
基金the financial support from the Program for New Century Excellent Talents in University (No.NCET-07-0138)the Science and Technology Project in Universities from the Education Department of Liaoning Province(No.2008T233).
文摘A novel thermoregulated phosphine ligand PhP(CHCHO)CH(n=22) was synthesized and used for the Rh-catalyzed hydroformylation of mixed Colefins in aqueous/organic biphasic system.Under the optimized conditions,pressure =5 MPa (H:CO=1:1),phosphine/Rh =13(molar ratio),reaction time =6 h and temperature =130℃,the conversion of Colefins and the yield of aldehyde are 99%and 94%,respectively.The catalyst retained in aqueous phase can be easily separated from the product-containing organic phase by simple phase separation and the catalytic activity remains almost constant after four consecutive cycles.
文摘Poly α-olefin,used as the drag reducing agent on the crude oil transportation,was analyzed by pyrolysis/gas chromatography-mass spectrometry(PY/GC-MS).Three polyolefin samples of polydecene,polyoctene and the copolymer of decene and octane,were analyzed.The samples were analyzed by increasing pyrolysis temperatures from 500 to 800 ℃.The result showed that the optimal pyrolysis temperature was 600 ℃.2-Methyl-decene and 2-methyl-pentadecene was selected as the characteristic pyrolysates for identification polydecene and polyoctene,respectively.The quantitative method of the copolymer was also discussed.Height peak of the characteristic pyrolysate was used to calculate the mass rate of the two monomers in the copolymers.The error of the method was-4.08%.