Solvent extraction kinetics of lanthanum with purified Cyanex 923 in heptane from nitrate medium was investigated by using a constant interfacial cell with laminar flow at 303 K. The effects of stirring speed, tempera...Solvent extraction kinetics of lanthanum with purified Cyanex 923 in heptane from nitrate medium was investigated by using a constant interfacial cell with laminar flow at 303 K. The effects of stirring speed, temperature and specific interface on the extraction rate were studied. The experimental results showed that the extraction apparent activation energy was 32.0 kJ\5mol -1 and the extraction process was controlled by both chemical reaction and diffusion. The extraction rates were measured at different chemical compositions by varying ionic strength, pH value and the concentration of purified Cyanex 923. The initial extraction rate equation was obtained.展开更多
The crystal structure of [Sm(m-NO2C6H4CO2)3(H2O)2] was determined.Mr=684. 66,triclinic,space group P1.α=11. 408(6),b=12.990(6).c=9.469(3) A,α=104. 84(3),β=92.84,γ=65.31(3)°,V=1229.9(9)A3.Z=2,Dc=1.85g/cm3, F(0...The crystal structure of [Sm(m-NO2C6H4CO2)3(H2O)2] was determined.Mr=684. 66,triclinic,space group P1.α=11. 408(6),b=12.990(6).c=9.469(3) A,α=104. 84(3),β=92.84,γ=65.31(3)°,V=1229.9(9)A3.Z=2,Dc=1.85g/cm3, F(000)=674,μ=25.1 cm-1,R=0.67.The coordination number of samarium ion is eight.The metal ions are bridged by carboxylato groups to form a polymeric chain structure.The crystal data of [Ho (m-NO2C6H4CO2)3 (H2O)2] were measured:triclinic,space group P1,α=11.368(3) .b=12. 943(3),c=9.443(1) A α=104.92(1),β=92.80(3),γ=65.07(2)°,V=1214.7(4)A 3,Z=2,Dc=1.91 g/cm3.These show that the samarium and holmium cornpounds are isomorphous.展开更多
By using the average band-gap model, the chemical bond properties of(La_(1-x)M_x)_2CuO_4(M=Ba, Sr) were calculated . The calculated covalencies for Cu-O and La-O bondin the compounds are 0.3 and 0.03 respectively. Mos...By using the average band-gap model, the chemical bond properties of(La_(1-x)M_x)_2CuO_4(M=Ba, Sr) were calculated . The calculated covalencies for Cu-O and La-O bondin the compounds are 0.3 and 0.03 respectively. Mossbauer isomer shifts of ^(57)Fe doped inLa_2CuO_4 and ^(119)Sn doped in La_2CuO_4 were calculated by using the chemical surrounding factordefined by covalency and electronic polarizability. Four valence state tin and three valence ironsites were identified in ^(57)Fe and ^(119)Sn展开更多
By using the chemical bond theory of dielectric description, the chemical bond parameters of (Tl, Pb) - 1223 was calculated. The results show that the Sr-O, Tl-O, and Ca-O types of bond have higher ionic character an...By using the chemical bond theory of dielectric description, the chemical bond parameters of (Tl, Pb) - 1223 was calculated. The results show that the Sr-O, Tl-O, and Ca-O types of bond have higher ionic character and the Cu-O types of bond have more covalent character. Mssbauer isomer shifts of 57Fe and 119Sn doped in (Tl, Pb) -1223 were calculated by using the chemical environmental factor, he, defined by covalency and electronic polarizability. Four valence state tin and three valence iron sites were identified in 57Fe, and 119Sn doped (Tl, Pb) -1223 superconductor. We conclude that all of the Fe atoms substitute the Cu at square planar Cu (1) site, whereas Sn prefers to substitute the square pyramidal Cu (2) site.展开更多
Monoclonal antibody technique was employed to detect the conformational difference of CaM induced by metal ions. A trivalent europium ion induced conformation-specific anti-calmodulin monoclonal antibody was successf...Monoclonal antibody technique was employed to detect the conformational difference of CaM induced by metal ions. A trivalent europium ion induced conformation-specific anti-calmodulin monoclonal antibody was successfully prepared with europium-saturated calmodulin as antigen.展开更多
The electronic structure and bonding of the cluster compound Sc7Cl10C2 have been studied by INDO method. In contract to the weak interaction between metal-metal in the compound Gd10Cl18C4, the bonding between metal at...The electronic structure and bonding of the cluster compound Sc7Cl10C2 have been studied by INDO method. In contract to the weak interaction between metal-metal in the compound Gd10Cl18C4, the bonding between metal atoms (Sc-Sc) in Sc7Cl10C2 is rather strong. The contribution of the orbitals 4s and 4p is larger than that of 3d to the Sc-Sc bond. In the cluster compound, besides Sc-Sc bonding, there are Sc -C and Sc -Cl bonds. The contribution of 3d is larger than that of 4s and 4p to the bond Sc-C. The contribution of 3d is slightly less than that of 4p and 4s to the bond Sc-Cl. Among the three kinds of bonds, the Sc-Cl bond is the weakest, the bond order of the Sc-Sc is close to that of the Sc-C.展开更多
The crystal structure of the complex [Li(THF)4]2[{(η5-CH3C5H4)Nd-Cl(μ2-Cl)NdCl2(η5-CH3C5H4)}2(μ4-O)] has been determined by X-ray diffraction technique. The crystal is monoclinic of space group C2/c with a = 22. 7...The crystal structure of the complex [Li(THF)4]2[{(η5-CH3C5H4)Nd-Cl(μ2-Cl)NdCl2(η5-CH3C5H4)}2(μ4-O)] has been determined by X-ray diffraction technique. The crystal is monoclinic of space group C2/c with a = 22. 740(7) ,b= 18. 319 (6),c=18. 330(6) A,β=93. 04(3)°,V = 7624. 93A3,Dc= 1. 55g/cm3,Z = 4,F(000) = 2800,μ=15. 02cm-1. The complex is consisted of two [Li(THF)4]+cations and one [{(η5-CH3C5H4)NdCl(μ2-Cl)NdCl2(η5-CH3C5H4)}2(μ4-O)]2-dianion. The two units [Cη5-CH3C5H4)NdCl(μ2-Cl)NdCl2(η5-CH3C5H4)] in the tetra nnclear-neodymium dianion are connected by a μ4-O bridge with the average Nd -μ4-O 2. 36(1) A ,Nd -C(ring) 2. 76(3)A,Nd-Cl 2. 823(7)A and Nd-μ2-Cl 2. 798(7)A.展开更多
The crystal and molecular structure of [Li+(DME)3]2[(CpNd)4 (μ2-CH3)2(μ4-O) (μ2-Cl)6]2~was determined from single crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P21/n with lattice...The crystal and molecular structure of [Li+(DME)3]2[(CpNd)4 (μ2-CH3)2(μ4-O) (μ2-Cl)6]2~was determined from single crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P21/n with lattice parameters a= 14. 614(5), b= 18. 683 (5),c= 24. 595 (6) A, β = ,91-85(2)°, V = 6712(3) A3,2 = 4,DC = 1. 63g/cm3,F(000) = 3256,Mr=1650. 85. The structure was solved by direct methods and Fourier techniques and refined by least-squares to a final R=0. 047,RW = 0. 049 for 3761 with I>3σ(I). The result revealed that the anion [(CpNd)4(μ4-O) (μ2-Cl)6(μ2-CH3)2]2- is composed of four neodymium (Ⅲ) atoms bridged by six Cl atoms, two methyl groups and one oxygen atom, and every Nd is bonded to a cyclopentadienyl group. The four Nd atoms form a distorted tetrahedron. The cations are composed of two Li+(DME)3 with average Li-O distance of 2. 120(40) A.展开更多
By using the chemical bond theory of dielectric description, the chemical bond parameters of (Hg, Pb) 1223 were calculated. The results show that the (Ba, Sr) O and Ca-O types of bond have higher ionic character, wh...By using the chemical bond theory of dielectric description, the chemical bond parameters of (Hg, Pb) 1223 were calculated. The results show that the (Ba, Sr) O and Ca-O types of bond have higher ionic character, while the Cu-O and (Hg, Pb) O types of bond have more covalent character. Mssbauer isomer shifts of 57 Fe and 119 Sn doped in (Hg, Pb) 1223 were calculated by using the chemical environmental factor, h e, defined by covalency and electronic polarizability. Four valence state tin and three valence iron sites were identified in 57 Fe and 119 Sn doped (Hg, Pb) 1223 superconductor. It can be concluded that all of the Fe atoms substitute the Cu at square planar Cu(1) site, whereas Sn prefers to substitute the square pyramidal Cu(2) site.展开更多
文摘Solvent extraction kinetics of lanthanum with purified Cyanex 923 in heptane from nitrate medium was investigated by using a constant interfacial cell with laminar flow at 303 K. The effects of stirring speed, temperature and specific interface on the extraction rate were studied. The experimental results showed that the extraction apparent activation energy was 32.0 kJ\5mol -1 and the extraction process was controlled by both chemical reaction and diffusion. The extraction rates were measured at different chemical compositions by varying ionic strength, pH value and the concentration of purified Cyanex 923. The initial extraction rate equation was obtained.
文摘The crystal structure of [Sm(m-NO2C6H4CO2)3(H2O)2] was determined.Mr=684. 66,triclinic,space group P1.α=11. 408(6),b=12.990(6).c=9.469(3) A,α=104. 84(3),β=92.84,γ=65.31(3)°,V=1229.9(9)A3.Z=2,Dc=1.85g/cm3, F(000)=674,μ=25.1 cm-1,R=0.67.The coordination number of samarium ion is eight.The metal ions are bridged by carboxylato groups to form a polymeric chain structure.The crystal data of [Ho (m-NO2C6H4CO2)3 (H2O)2] were measured:triclinic,space group P1,α=11.368(3) .b=12. 943(3),c=9.443(1) A α=104.92(1),β=92.80(3),γ=65.07(2)°,V=1214.7(4)A 3,Z=2,Dc=1.91 g/cm3.These show that the samarium and holmium cornpounds are isomorphous.
文摘By using the average band-gap model, the chemical bond properties of(La_(1-x)M_x)_2CuO_4(M=Ba, Sr) were calculated . The calculated covalencies for Cu-O and La-O bondin the compounds are 0.3 and 0.03 respectively. Mossbauer isomer shifts of ^(57)Fe doped inLa_2CuO_4 and ^(119)Sn doped in La_2CuO_4 were calculated by using the chemical surrounding factordefined by covalency and electronic polarizability. Four valence state tin and three valence ironsites were identified in ^(57)Fe and ^(119)Sn
文摘By using the chemical bond theory of dielectric description, the chemical bond parameters of (Tl, Pb) - 1223 was calculated. The results show that the Sr-O, Tl-O, and Ca-O types of bond have higher ionic character and the Cu-O types of bond have more covalent character. Mssbauer isomer shifts of 57Fe and 119Sn doped in (Tl, Pb) -1223 were calculated by using the chemical environmental factor, he, defined by covalency and electronic polarizability. Four valence state tin and three valence iron sites were identified in 57Fe, and 119Sn doped (Tl, Pb) -1223 superconductor. We conclude that all of the Fe atoms substitute the Cu at square planar Cu (1) site, whereas Sn prefers to substitute the square pyramidal Cu (2) site.
基金This work was financially supported by a grant from the Science Foundation of Guangzhou (2000-Z-076-01) and Laboratory of Rare Earth Chemistry and Physics Changchun Institute of Applied Chemistry Chinese Academy of Science.
基金This work is financially supported by the NNSF (No.29890280).
文摘Monoclonal antibody technique was employed to detect the conformational difference of CaM induced by metal ions. A trivalent europium ion induced conformation-specific anti-calmodulin monoclonal antibody was successfully prepared with europium-saturated calmodulin as antigen.
文摘The electronic structure and bonding of the cluster compound Sc7Cl10C2 have been studied by INDO method. In contract to the weak interaction between metal-metal in the compound Gd10Cl18C4, the bonding between metal atoms (Sc-Sc) in Sc7Cl10C2 is rather strong. The contribution of the orbitals 4s and 4p is larger than that of 3d to the Sc-Sc bond. In the cluster compound, besides Sc-Sc bonding, there are Sc -C and Sc -Cl bonds. The contribution of 3d is larger than that of 4s and 4p to the bond Sc-C. The contribution of 3d is slightly less than that of 4p and 4s to the bond Sc-Cl. Among the three kinds of bonds, the Sc-Cl bond is the weakest, the bond order of the Sc-Sc is close to that of the Sc-C.
文摘The crystal structure of the complex [Li(THF)4]2[{(η5-CH3C5H4)Nd-Cl(μ2-Cl)NdCl2(η5-CH3C5H4)}2(μ4-O)] has been determined by X-ray diffraction technique. The crystal is monoclinic of space group C2/c with a = 22. 740(7) ,b= 18. 319 (6),c=18. 330(6) A,β=93. 04(3)°,V = 7624. 93A3,Dc= 1. 55g/cm3,Z = 4,F(000) = 2800,μ=15. 02cm-1. The complex is consisted of two [Li(THF)4]+cations and one [{(η5-CH3C5H4)NdCl(μ2-Cl)NdCl2(η5-CH3C5H4)}2(μ4-O)]2-dianion. The two units [Cη5-CH3C5H4)NdCl(μ2-Cl)NdCl2(η5-CH3C5H4)] in the tetra nnclear-neodymium dianion are connected by a μ4-O bridge with the average Nd -μ4-O 2. 36(1) A ,Nd -C(ring) 2. 76(3)A,Nd-Cl 2. 823(7)A and Nd-μ2-Cl 2. 798(7)A.
文摘The crystal and molecular structure of [Li+(DME)3]2[(CpNd)4 (μ2-CH3)2(μ4-O) (μ2-Cl)6]2~was determined from single crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P21/n with lattice parameters a= 14. 614(5), b= 18. 683 (5),c= 24. 595 (6) A, β = ,91-85(2)°, V = 6712(3) A3,2 = 4,DC = 1. 63g/cm3,F(000) = 3256,Mr=1650. 85. The structure was solved by direct methods and Fourier techniques and refined by least-squares to a final R=0. 047,RW = 0. 049 for 3761 with I>3σ(I). The result revealed that the anion [(CpNd)4(μ4-O) (μ2-Cl)6(μ2-CH3)2]2- is composed of four neodymium (Ⅲ) atoms bridged by six Cl atoms, two methyl groups and one oxygen atom, and every Nd is bonded to a cyclopentadienyl group. The four Nd atoms form a distorted tetrahedron. The cations are composed of two Li+(DME)3 with average Li-O distance of 2. 120(40) A.
基金ProjectsupportedbytheNationalNaturalScienceFoundationofChina (No .2 98710 2 9)
文摘By using the chemical bond theory of dielectric description, the chemical bond parameters of (Hg, Pb) 1223 were calculated. The results show that the (Ba, Sr) O and Ca-O types of bond have higher ionic character, while the Cu-O and (Hg, Pb) O types of bond have more covalent character. Mssbauer isomer shifts of 57 Fe and 119 Sn doped in (Hg, Pb) 1223 were calculated by using the chemical environmental factor, h e, defined by covalency and electronic polarizability. Four valence state tin and three valence iron sites were identified in 57 Fe and 119 Sn doped (Hg, Pb) 1223 superconductor. It can be concluded that all of the Fe atoms substitute the Cu at square planar Cu(1) site, whereas Sn prefers to substitute the square pyramidal Cu(2) site.
