The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric a...The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric acid （HDEHP, H2A2（0）） and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester （HEH/EHP, H2L2（0）） were studied. The distribution ratios and synergistic coefficients of Nd^3＋ and Sm^3＋ in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm^3＋ or Nd^3＋. The chemical compositions of the extracted complex were determined as Nd.（HA2）2-HL2 and Sm.（HA2）2-HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.展开更多
In view of the importance of solvent extraction of rare earth metals with the acidic organophosphorous reagent,the development of a chemically based model applicable to high concentration is desired.In the present stu...In view of the importance of solvent extraction of rare earth metals with the acidic organophosphorous reagent,the development of a chemically based model applicable to high concentration is desired.In the present study,the equilibrium distribution of dysprosium(Ⅲ)between an aqueous nitric acid solution and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC88A)was measured in the range of an initial aqueous dysprosium(Ⅲ)concentration from 1.0×10-3to 1.0×10-1kmol/m 3and PC88A concentration from 0.16 to 0.65 kmol/m3in Shellsol D70 as the diluent.The obtained data were analyzed using the chemically based model in order to correlate the equilibrium distribution ratios.In this model,dysprosium(Ⅲ)was assumed to be extracted with the PC88A dimer as a 1:3 complex,the activities were considered for the aqueous species,and the effective concentration of the PC88A dimer was calculated using Alstad's empirical equation.As a result,the apparent extraction equilibrium constant was determined to be 253(kmol·m- 3)-2with an excellent correlation between the experiment and calculation results in the wide range of the logarithm of the distribution ratio from-2 to 3.5.In conclusion,the methodology in this model would be effective for quantitative description of solvent extraction behavior of general rare earth elements as well as dysprosium.展开更多
The synergistic extraction of Pr^3＋ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester （P507, HL） and 8-Hydroxyquinoline （HQ） in heptane was investigated. The effect o...The synergistic extraction of Pr^3＋ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester （P507, HL） and 8-Hydroxyquinoline （HQ） in heptane was investigated. The effect of equilibrium of aqueous acidity on extraction of Pr^3＋ was discussed. The effect of extractant concentraction, different diluents, equilibrium time and acetate ion concentration oil extraction reaction were also studied. With a method of double-logarithmic slope, composition of the extracted species on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline was derived. The result shows that the synergistic extraction system not only overcomes emulsification of 8-Hydroxyquinoline, but also shows perfect capacity of synergistic extraction. The largest synergistic enhancement factor can be calculated to be 5.49 at pH 3.6 for Pr^3＋.展开更多
The chemistry of extraction of lanthanide and yttrium by 2-ethylhexylphosphonic acidmono-2-ethylhexyl ester in n-dodecane from nitric acid is described. By M W determination, NMR and the slope method, the extraction r...The chemistry of extraction of lanthanide and yttrium by 2-ethylhexylphosphonic acidmono-2-ethylhexyl ester in n-dodecane from nitric acid is described. By M W determination, NMR and the slope method, the extraction reaction is studied.Based upon elementery analyses, IR, NMR as well as MW determination, the compositions ofthe complexes formed with La（NO3）3 and Nd（NO3）3 are studied. Both the standard enthalprchanges（-△H°） and the relative free energy and entropy changes （-△Zr°）（△SPr°）of the ex-.traction reaction are also estimated. The regularity of the variations of Kea（concentrationequilibrium constant）, -△AZr° and △Sr°reveals the tetrad effect. The average separationfactor of the adjacent lanthanides is calculated to be as high as 3.04.展开更多
The chemistry of essential obtained from the leaves of Senna podocarpa (Guill. Et Perr.) Lock from Nigeria is being reported. The hydrodistilled oil was analyzed by gas chromatography-flame ionization detector (GC-FID...The chemistry of essential obtained from the leaves of Senna podocarpa (Guill. Et Perr.) Lock from Nigeria is being reported. The hydrodistilled oil was analyzed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) techniques. The main constituents of the oil were 1,2-benzenedicarboxylic acid, mono (2-ethylhexyl) ester phthalate (26.6%) and β-elemene (27.9%). There were significant amounts of caryophyllene oxide (7.3%) and urs-12-en-24-oic acid, 3-oxo-methyl ester (5.5%). The antimicrobial activity of the essential oil was evaluated against a panel of seven bacteria and two fungal strain using agar diffusion and broth microdilution methods. Results had shown that the oil exhibited moderate to strong antimicrobial activity against the tested microorganisms. The activity zones of inhibition (ZI) ranged between 10.0 ± 0.2 mm and 28.3 ± 2.9 mm while the minimum inhibitory concentrations (MIC) ranged between 0.3 mg/mL 5.0 mg/mL, respectively. The chemical constituents and antimicrobial activity of the essential oil of Senna podocarpa were being reported for the first time.展开更多
AIM： To investigate the chemical constituents of Fitex negundo. METHOD： Compounds were isolated by different chromatographic methods and their structures were elucidated on the basis of NMR spectroscopy. RESULTS： F...AIM： To investigate the chemical constituents of Fitex negundo. METHOD： Compounds were isolated by different chromatographic methods and their structures were elucidated on the basis of NMR spectroscopy. RESULTS： Four compounds were isolated and identified as 2a, 3a, 24-trihydroxyurs-12, 20（30）-dien-28-oic acid-28-O- β-D-glucopyranosyl ester （1）, corosolic acid （2）, vulgarsaponin A （3） and 2a, 3a, 24-trihydroxyurs-12-en-28-oic acid-28-O-β-D- glucopyranosyl ester （4）, respectively. CONCLUSION： Compound I is a new triterpenoid glycoside.展开更多
基金the National Natural Science Foundation of China (50674016)the National High Technology Research and Develop-ment Program of China (863 Program) ( 2006AA06Z123)
文摘The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric acid （HDEHP, H2A2（0）） and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester （HEH/EHP, H2L2（0）） were studied. The distribution ratios and synergistic coefficients of Nd^3＋ and Sm^3＋ in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm^3＋ or Nd^3＋. The chemical compositions of the extracted complex were determined as Nd.（HA2）2-HL2 and Sm.（HA2）2-HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.
基金the Japan Society for the Promotion of Science for supporting this fellowship work(No.07616)
文摘In view of the importance of solvent extraction of rare earth metals with the acidic organophosphorous reagent,the development of a chemically based model applicable to high concentration is desired.In the present study,the equilibrium distribution of dysprosium(Ⅲ)between an aqueous nitric acid solution and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC88A)was measured in the range of an initial aqueous dysprosium(Ⅲ)concentration from 1.0×10-3to 1.0×10-1kmol/m 3and PC88A concentration from 0.16 to 0.65 kmol/m3in Shellsol D70 as the diluent.The obtained data were analyzed using the chemically based model in order to correlate the equilibrium distribution ratios.In this model,dysprosium(Ⅲ)was assumed to be extracted with the PC88A dimer as a 1:3 complex,the activities were considered for the aqueous species,and the effective concentration of the PC88A dimer was calculated using Alstad's empirical equation.As a result,the apparent extraction equilibrium constant was determined to be 253(kmol·m- 3)-2with an excellent correlation between the experiment and calculation results in the wide range of the logarithm of the distribution ratio from-2 to 3.5.In conclusion,the methodology in this model would be effective for quantitative description of solvent extraction behavior of general rare earth elements as well as dysprosium.
文摘The synergistic extraction of Pr^3＋ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester （P507, HL） and 8-Hydroxyquinoline （HQ） in heptane was investigated. The effect of equilibrium of aqueous acidity on extraction of Pr^3＋ was discussed. The effect of extractant concentraction, different diluents, equilibrium time and acetate ion concentration oil extraction reaction were also studied. With a method of double-logarithmic slope, composition of the extracted species on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline was derived. The result shows that the synergistic extraction system not only overcomes emulsification of 8-Hydroxyquinoline, but also shows perfect capacity of synergistic extraction. The largest synergistic enhancement factor can be calculated to be 5.49 at pH 3.6 for Pr^3＋.
文摘The chemistry of extraction of lanthanide and yttrium by 2-ethylhexylphosphonic acidmono-2-ethylhexyl ester in n-dodecane from nitric acid is described. By M W determination, NMR and the slope method, the extraction reaction is studied.Based upon elementery analyses, IR, NMR as well as MW determination, the compositions ofthe complexes formed with La（NO3）3 and Nd（NO3）3 are studied. Both the standard enthalprchanges（-△H°） and the relative free energy and entropy changes （-△Zr°）（△SPr°）of the ex-.traction reaction are also estimated. The regularity of the variations of Kea（concentrationequilibrium constant）, -△AZr° and △Sr°reveals the tetrad effect. The average separationfactor of the adjacent lanthanides is calculated to be as high as 3.04.
文摘The chemistry of essential obtained from the leaves of Senna podocarpa (Guill. Et Perr.) Lock from Nigeria is being reported. The hydrodistilled oil was analyzed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) techniques. The main constituents of the oil were 1,2-benzenedicarboxylic acid, mono (2-ethylhexyl) ester phthalate (26.6%) and β-elemene (27.9%). There were significant amounts of caryophyllene oxide (7.3%) and urs-12-en-24-oic acid, 3-oxo-methyl ester (5.5%). The antimicrobial activity of the essential oil was evaluated against a panel of seven bacteria and two fungal strain using agar diffusion and broth microdilution methods. Results had shown that the oil exhibited moderate to strong antimicrobial activity against the tested microorganisms. The activity zones of inhibition (ZI) ranged between 10.0 ± 0.2 mm and 28.3 ± 2.9 mm while the minimum inhibitory concentrations (MIC) ranged between 0.3 mg/mL 5.0 mg/mL, respectively. The chemical constituents and antimicrobial activity of the essential oil of Senna podocarpa were being reported for the first time.
基金supported by the Program for Changjiang Scholars and Innovative Research Team in the University(No.IRT0965)the Team Project of Natural Science Foundation of Guangdong Province(No.8351063201000003)the Science and Technology Planning Project of Guangdong Province(No.2012A080204005)
文摘AIM： To investigate the chemical constituents of Fitex negundo. METHOD： Compounds were isolated by different chromatographic methods and their structures were elucidated on the basis of NMR spectroscopy. RESULTS： Four compounds were isolated and identified as 2a, 3a, 24-trihydroxyurs-12, 20（30）-dien-28-oic acid-28-O- β-D-glucopyranosyl ester （1）, corosolic acid （2）, vulgarsaponin A （3） and 2a, 3a, 24-trihydroxyurs-12-en-28-oic acid-28-O-β-D- glucopyranosyl ester （4）, respectively. CONCLUSION： Compound I is a new triterpenoid glycoside.
