The effects of CO2 pressure,temperature and concentration on asphaltene precipitation induced by CO2 were studied using a high-pressure vessel,interfacial tensiometer,Fourier transform infrared （FTIR） and drill core...The effects of CO2 pressure,temperature and concentration on asphaltene precipitation induced by CO2 were studied using a high-pressure vessel,interfacial tensiometer,Fourier transform infrared （FTIR） and drill core displacement experimental apparatus.The results indicated that the content of asphaltene in crude oil decreased,and the interfacial tension between a model oil and distilled water increased,with an increase of CO2 pressure,decrease of temperature and increase of molar ratio of CO2 to crude oil when CO2 contacted crude oil in the high pressure vessel.The content of asphaltene in sweepout oil and the permeability of test cores both also decreased with an increase of CO2 flooding pressure.The main reason for changes in content of asphaltene in crude oil,in interfacial tension between model oil and distilled water and in the permeability of the test core is the precipitation of asphaltene which is an interfacially active substance in crude oil.Precipitation of asphaltene also blocks pores in the drill core which decreases the permeability.展开更多
The crystallography and morphology of precipitates in different systems were rationalized based on the optimum matching conditions. The interfaces that obey these conditions were conveniently identified in reciprocal ...The crystallography and morphology of precipitates in different systems were rationalized based on the optimum matching conditions. The interfaces that obey these conditions were conveniently identified in reciprocal space,in terms of three △g's parallelism rules. The theoretic basis of the O-lattice and CSL/DSC theory for these rules was provided briefly. Examples of small lattice misfit system(a Ti alloy),and large lattice misfit systems(Al and Mg alloys) were presented. The effect of lattice parameters on the orientation relationship and morphology was also discussed.展开更多
Crusher hammers for the mineral processing industry must meet the demands of both high wear resistance at the hammer head and high impact toughness at the hammer handle. The crusher hammers made of Hadfield steel have...Crusher hammers for the mineral processing industry must meet the demands of both high wear resistance at the hammer head and high impact toughness at the hammer handle. The crusher hammers made of Hadfield steel have typical y low service life of less than 40 hours. To solve the problem, a kind of bimetal crusher hammers made of high chromium cast iron （HCCI） and low al oy steel （LAS） has been successful y developed by using liquid-liquid composite casting. The microstructure and composite interface bonding was analyzed using optical microscope, SEM, EDX and XRD. Micrographs indicate that the composite interface is metal urgical y bonded with a zigzag shape across the boundary and without unbound region or void. After heat treatment, the composite hammers have shown excellent properties. The hardness of HCCI is at least 63 HRC and its αk is greater than 3.5 J？cm-2; the hardness of LAS is greater than 35 HRC and its αk is no less than 80 J？cm-2. Diffusion of elements takes place at the interface and forms a transition region. The micro hardness increases from LAS to the interface and then to HCCI. Wear comparison was made separately between the bimetal composite hammer and a Hadfield steel hammer in two quarries of Jilin province and Liaoning province. The results showed that the liquid-liquid bimetal composite hammers did not have the fal ing off of hammer head or impact fracture phenomenon, and their service life was 3.75 times as long as that of the Hadfield steel hammers.展开更多
The segregated flow pattern, which occurs in a 26.1 mm diameter, horizontal, stainless steel test section, is investigated. Pressure gradient and in situ phase distribution data were obtained for different combination...The segregated flow pattern, which occurs in a 26.1 mm diameter, horizontal, stainless steel test section, is investigated. Pressure gradient and in situ phase distribution data were obtained for different combinations of phase superficial velocities ranging from 0.05 m.s^-1 to 0,96 m.s^-1. For the current small Eoetvoes number liquid-liquid system （EOD=4.77）, the dominant effect of interfacial tension and wall-wetting properties of the liquids over the gravity is considered. The approach introduces the closure relationship for the case of turbulent flow m a rough pipe, and attempts to modify the two-fluid model to account for the curved interface. In present flow rates range, wave amplitudes were found small, while interfacial mixing was observed. An adjustable definition for hydraulic diame- ters of two fluids and interfacial friction factor is adopted. The predicted pressure gradient and in situ phase distribution data have been compared with present experimental data and those reported in the literature.展开更多
Twinning and precipitation play important roles in deformation and strengthening of magnesium alloys.In this work,interfacial precipitation in{1012}twin boundaries(TBs)of a cold-stamped Mg-12Gd-1.2Zn-0.4Zr alloy was i...Twinning and precipitation play important roles in deformation and strengthening of magnesium alloys.In this work,interfacial precipitation in{1012}twin boundaries(TBs)of a cold-stamped Mg-12Gd-1.2Zn-0.4Zr alloy was investigated using atomic-resolution high-angle annular dark-field scanning transmission electron microscopy.Extended periodic segregation of Gd+Zn atoms in the~86.2°{1012}TBs with basal-prismatic facets and in the symmetric tilting TBs(obviously>86.2°)frequently occurred,resulted in the formation of new interfacial phases,namelyβ_(TB)’having a monoclinic structure in the TBs with two segregation layers andβ_(TB) having a tetragonal structure in the TBs with three or more segregation layers.The formation ofβ_(TB) clearly accelerates peak-aging and improves the alloy’s strength.展开更多
Objective:Pretreatment of biological samples is the most critical step in pharmacokinetic studies,especially pre-treatment of plasma samples.The pretreatment of biological samples in pharmacokinetic study of Tradition...Objective:Pretreatment of biological samples is the most critical step in pharmacokinetic studies,especially pre-treatment of plasma samples.The pretreatment of biological samples in pharmacokinetic study of Traditional Chinese Medicines (TCM) is difficult due to the complexity of the ingredients.An organic solvent system ethyl acetate:acetone (10:1) solution used for liquid-liquid extraction has been developed in this study and compared with the commonly used protein precipitation method.Methods:Rats,Beagle dogs and humans plasma samples were adopted in this study in order to demonstrate the universality of the pretreatment method.Feasibility of this pretreatment method was also verified through its application to the pharmacokinetics of rhubarb in rats.Results:According to the results of extraction recovery matrix effect,it was indicated that the liquid-liquid extraction methods with new organic solvent might be suitable for variety of structures of compounds and various types of plasma samples.The pharmacokinetic study result showed that the developed pretreatment method could successfully be used for simultaneous determination of three active compounds modin,emodin-8-O-β-D-glucopyranoside (EDG) and rhein in rat plasma with high sensitivity,accuracy,and recovery by liquid chromatography tandem mass spectrometry (LC-MS/MS).Conclusion:The pretreatment method of liquid-liquid extraction methods with new organic solvent could be successfully applied for multi-component pharmacokinetics of TCM.展开更多
Ionic liquids are possible alternative solvents for the separation of aromatic and aliphatic hydrocarbons by liquid-liquid extrac- tion. Interfacial tension is an important property to consider in the design of liquid...Ionic liquids are possible alternative solvents for the separation of aromatic and aliphatic hydrocarbons by liquid-liquid extrac- tion. Interfacial tension is an important property to consider in the design of liquid-liquid extraction processes. In this work, the liquid-liquid interfacial tension and the mutual solubility at 25 ℃ have been measured for a series of biphasic, equilibrated mixtures of an ionic liquid and a hydrocarbon. In particular, the ionic liquids 1-alkyl-3-methylimidazolium bis（trifluorome- thanesulfonyl）imide （with the alkyl substituent being ethyl, hexyl or decyl）, 1-ethyl-3-methylimidazolium ethylsulfate, and 1-ethyl-3-methylimidazolium methanesulfonate have been selected, as well as the hydrocarbons benzene, hexane, ethylben- zene, and octane. The selected sets of ionic liquids and hydrocarbons allow the analysis of the influence of a series of effects on the interfacial tension. For example, the interfacial tension decreases with an increase in the length of the alkyl substituent chain of the cation or with an increase of the degree of charge delocalisation in the anion of the ionic liquid. Also, the interfa- cial tension with the aromatic hydrocarbons is markedly lower than that with the aliphatic hydrocarbons. A smaller effect is caused by variation of the size of the hydrocarbon. Some of the observed trends can be explained from the mutual solubility of the hydrocarbon and the ionic liquid.展开更多
基金supported by the National Key Technologies R&D Program(2012BAC24B02)Basic Subject Fund of China University of Petroleum-Beijing(KYJJ2012-07-01)+1 种基金Basic Subject Fund of China University of Petroleum-Beijing(No.YJRC-2013-20)National Natural Science Foundation of China(51304222)
文摘The effects of CO2 pressure,temperature and concentration on asphaltene precipitation induced by CO2 were studied using a high-pressure vessel,interfacial tensiometer,Fourier transform infrared （FTIR） and drill core displacement experimental apparatus.The results indicated that the content of asphaltene in crude oil decreased,and the interfacial tension between a model oil and distilled water increased,with an increase of CO2 pressure,decrease of temperature and increase of molar ratio of CO2 to crude oil when CO2 contacted crude oil in the high pressure vessel.The content of asphaltene in sweepout oil and the permeability of test cores both also decreased with an increase of CO2 flooding pressure.The main reason for changes in content of asphaltene in crude oil,in interfacial tension between model oil and distilled water and in the permeability of the test core is the precipitation of asphaltene which is an interfacially active substance in crude oil.Precipitation of asphaltene also blocks pores in the drill core which decreases the permeability.
基金Projects(59871021, 50271035, 50471012) supported by the National Natural Science Foundation of China.
文摘The crystallography and morphology of precipitates in different systems were rationalized based on the optimum matching conditions. The interfaces that obey these conditions were conveniently identified in reciprocal space,in terms of three △g's parallelism rules. The theoretic basis of the O-lattice and CSL/DSC theory for these rules was provided briefly. Examples of small lattice misfit system(a Ti alloy),and large lattice misfit systems(Al and Mg alloys) were presented. The effect of lattice parameters on the orientation relationship and morphology was also discussed.
基金financially supported by the National Foundation (grant No:51371090)the Science and Technology Support Program of the 12th Five-year Plan (grant No:2011BAD20B03010401)+1 种基金the National Natural Science Foundation of China (grant No:51203061)the College Student Science and Technology Innovation of Hei Longjiang Province (grant No:2012sj001)
文摘Crusher hammers for the mineral processing industry must meet the demands of both high wear resistance at the hammer head and high impact toughness at the hammer handle. The crusher hammers made of Hadfield steel have typical y low service life of less than 40 hours. To solve the problem, a kind of bimetal crusher hammers made of high chromium cast iron （HCCI） and low al oy steel （LAS） has been successful y developed by using liquid-liquid composite casting. The microstructure and composite interface bonding was analyzed using optical microscope, SEM, EDX and XRD. Micrographs indicate that the composite interface is metal urgical y bonded with a zigzag shape across the boundary and without unbound region or void. After heat treatment, the composite hammers have shown excellent properties. The hardness of HCCI is at least 63 HRC and its αk is greater than 3.5 J？cm-2; the hardness of LAS is greater than 35 HRC and its αk is no less than 80 J？cm-2. Diffusion of elements takes place at the interface and forms a transition region. The micro hardness increases from LAS to the interface and then to HCCI. Wear comparison was made separately between the bimetal composite hammer and a Hadfield steel hammer in two quarries of Jilin province and Liaoning province. The results showed that the liquid-liquid bimetal composite hammers did not have the fal ing off of hammer head or impact fracture phenomenon, and their service life was 3.75 times as long as that of the Hadfield steel hammers.
基金the National High Technology Research and Development Program of China (2006AA09Z333)
文摘The segregated flow pattern, which occurs in a 26.1 mm diameter, horizontal, stainless steel test section, is investigated. Pressure gradient and in situ phase distribution data were obtained for different combinations of phase superficial velocities ranging from 0.05 m.s^-1 to 0,96 m.s^-1. For the current small Eoetvoes number liquid-liquid system （EOD=4.77）, the dominant effect of interfacial tension and wall-wetting properties of the liquids over the gravity is considered. The approach introduces the closure relationship for the case of turbulent flow m a rough pipe, and attempts to modify the two-fluid model to account for the curved interface. In present flow rates range, wave amplitudes were found small, while interfacial mixing was observed. An adjustable definition for hydraulic diame- ters of two fluids and interfacial friction factor is adopted. The predicted pressure gradient and in situ phase distribution data have been compared with present experimental data and those reported in the literature.
基金financially supported by the Scientific and Technological Developing Scheme of Jilin Province under grants No.YDZJ202102CXJD012,20200801048GH,20200602021ZPthe Capital Construction Founds of Jilin Province with Innovation Capacity Building under grants No.2021C038-1。
文摘Twinning and precipitation play important roles in deformation and strengthening of magnesium alloys.In this work,interfacial precipitation in{1012}twin boundaries(TBs)of a cold-stamped Mg-12Gd-1.2Zn-0.4Zr alloy was investigated using atomic-resolution high-angle annular dark-field scanning transmission electron microscopy.Extended periodic segregation of Gd+Zn atoms in the~86.2°{1012}TBs with basal-prismatic facets and in the symmetric tilting TBs(obviously>86.2°)frequently occurred,resulted in the formation of new interfacial phases,namelyβ_(TB)’having a monoclinic structure in the TBs with two segregation layers andβ_(TB) having a tetragonal structure in the TBs with three or more segregation layers.The formation ofβ_(TB) clearly accelerates peak-aging and improves the alloy’s strength.
文摘Objective:Pretreatment of biological samples is the most critical step in pharmacokinetic studies,especially pre-treatment of plasma samples.The pretreatment of biological samples in pharmacokinetic study of Traditional Chinese Medicines (TCM) is difficult due to the complexity of the ingredients.An organic solvent system ethyl acetate:acetone (10:1) solution used for liquid-liquid extraction has been developed in this study and compared with the commonly used protein precipitation method.Methods:Rats,Beagle dogs and humans plasma samples were adopted in this study in order to demonstrate the universality of the pretreatment method.Feasibility of this pretreatment method was also verified through its application to the pharmacokinetics of rhubarb in rats.Results:According to the results of extraction recovery matrix effect,it was indicated that the liquid-liquid extraction methods with new organic solvent might be suitable for variety of structures of compounds and various types of plasma samples.The pharmacokinetic study result showed that the developed pretreatment method could successfully be used for simultaneous determination of three active compounds modin,emodin-8-O-β-D-glucopyranoside (EDG) and rhein in rat plasma with high sensitivity,accuracy,and recovery by liquid chromatography tandem mass spectrometry (LC-MS/MS).Conclusion:The pretreatment method of liquid-liquid extraction methods with new organic solvent could be successfully applied for multi-component pharmacokinetics of TCM.
基金the Ministry of Economy and Competitiveness of the Spanish Government, for financial support through project CTQ2009-10776, and for H. Rodríguez's contract under the "Ramón y Cajal" program
文摘Ionic liquids are possible alternative solvents for the separation of aromatic and aliphatic hydrocarbons by liquid-liquid extrac- tion. Interfacial tension is an important property to consider in the design of liquid-liquid extraction processes. In this work, the liquid-liquid interfacial tension and the mutual solubility at 25 ℃ have been measured for a series of biphasic, equilibrated mixtures of an ionic liquid and a hydrocarbon. In particular, the ionic liquids 1-alkyl-3-methylimidazolium bis（trifluorome- thanesulfonyl）imide （with the alkyl substituent being ethyl, hexyl or decyl）, 1-ethyl-3-methylimidazolium ethylsulfate, and 1-ethyl-3-methylimidazolium methanesulfonate have been selected, as well as the hydrocarbons benzene, hexane, ethylben- zene, and octane. The selected sets of ionic liquids and hydrocarbons allow the analysis of the influence of a series of effects on the interfacial tension. For example, the interfacial tension decreases with an increase in the length of the alkyl substituent chain of the cation or with an increase of the degree of charge delocalisation in the anion of the ionic liquid. Also, the interfa- cial tension with the aromatic hydrocarbons is markedly lower than that with the aliphatic hydrocarbons. A smaller effect is caused by variation of the size of the hydrocarbon. Some of the observed trends can be explained from the mutual solubility of the hydrocarbon and the ionic liquid.
