[en] A study of the synergistic extraction of uranium (VI) from sulphuric acid solution with the chelating agent 1-phenyl-3-methyl-4-(2'-chloro benzoyl)-pyrazolone-5 (PMCBP) together with di(2-ethylhexyl) phosphoric acid (HDEHP) and also mono-(2-ethylhexyl)-2-ethylhexylphosphate (HEHEHP) is described. The experimental results indicate that the synergistic extraction species is not an individual complex, but rather a mixture of UO₂HA₂X and UO₂HA₂HXX'. The mechanisms of extraction is discussed

[en] The synthesis and the property of polymer oxidizing agent which is suitable for halogen radiolabeling, a high-speed, no-carrier-added solid phase labelling method and its reactor are described. An electrified rhodamine and cholesterol were radiolabelled by the method, and their products were identified. The radiochemical purity of each radiolabelled compound was more than 95% and radioactive recovery ratio was more than 96%. It realized high-speed labelling of five minutes. The solid phase labelling method for the substance that can form organo mercury compound is discussed

[en] The transient changes in UV absorbance of the vibrationally excited UF₆ molecules in the UV region of 220-330 nm have been investigated. The UF₆ molecules are excited from pulsed CO₂ laser pumped SF₆ by a V-V energy transfer process. Under static condition, the influences of CO₂ laser fluence, SF₆ and UF₆ partial pressure upon the UV absorption changes have been measured. For a 2.0 Torr SF₆ and 2.0 Torr UF₆ mixture and at laser pulsed energy of 160 +- 10 mJ, the UV absorption spectrum of vibrationally excited UF₆ molecules shows existence of four absorption peaks at 240, 248, 290 and 313 nm, respectively. It may be related to the UV absorption of several higher vibrationally excited UF₆ molecules

[en] Thirteen solid lanthanide(III) complexes of 18-membered N₃O₃ hexadentate macrocyclic schiff-base ligand containing pyridyl group have been prepared by template reaction. Their compositions and structures were ascertained by elemental analyses, infrared spectra, electrical conductance measurements and differential thermal analyses. The solubility and thermal stability of these complexes have been studied as well

[en] Through the analysis of the balance between the coordination bond and Van der Waals energies of several complex compounds of uranium, we found that the coordination bond energy and the maximum Van der Waals attractive energy between the coordination atoms are nearly the same. This is a strong support for the Packing Model and will be the foundation for the future development of that model

[en] The Mossbauer spectra of compounds with general formula [(π-C₅O₅)Fe-(CO₂)]₂Sn (X)(Y) were studied. The corresponding parameters showed that the parameters for iron were assentially independent on the nature of X and Y. The alternation of X and Y caused the change in s electron density through the shielding of s electron or the substitutents inductive effect and subsequently caused the change of tin isomer shifts. The fact that X and Y groups had little effect on iron parameters might be a good evidence for the absence of π interaction between Fe and Sn

[en] The ENDOR spectra of the ¹⁵N-⁶³Cu-HAP complex measured in 5:1 DMSOEtOH solution at 20 K were studied by orientation selection technique. The anisotropic super-hyperfine coupling tensor of ligand ¹⁵N nucleus and the super-hyperfine coupling constant of several unequal values ¹H nuclei were accurately determined. The result shows that in previous paper the method of spectral analysis is right and the data is reliable

[en] The acid dissociation constants of 3, 6-bis (methyleneiminodiactic acid) catechol (CBMIDA), the stability constants of its Mg(II), Ca(II), Sr(II), Ba(II), Mn(II), Cd(II), Co(II), Ni(II), Zn(II), Cu(II), Fe(III), Th(IV) and U(VI) complexes and the protonation constants of the metal complexes were determined pH-metrically in aqueous solutions at 25.0 ± 0.1 deg C in the presence of 0.1 mol · dm^-3 potassium nitrate. The mechanism of the stepwise acid dissociation equilibria of CBMIDA was presented and the coordination forms of the metal complexes were discussed

[en] A pNa method used for determining the stability constants is reported and applied to the study on coordination reaction of benzo-15-crown-5 (L1) and 4'-nitrobenzo-15-crown-5 (L2) with 10 rare earth ions in methanol solution, and their stability constants are calculated according to the formation of 1:1 coordination compounds. It is found that the coordination capability of L2 to rare earth ions is stronger than that of L1, especially with heavy rare earth. The coordination behavior of L1 and L2 towards yttrium (III) is studied under the same conditions. It is observed that log KY3+ of L2 is larger than that of L1, which is similar to the regularity that the coordination capability of L2 with Ln3+ is stronger than that of L1. This shows that L1 and L2 are also similar as to the property of solution coordination compounds of yttrium and lanthanum with the two ligands. Comparing the log K of the coordination compounds formed by coordinating of the 3 kinds of ions whose radii are similar but their electric charges are different with the ligand L1, the following result is obtained: logKNa+ > logKCa2+ > logKLa3+, but with L2, the result is logKCa2+ > logKLa3+ > logKNa+

[en] Lanthanide ions were used as NMR probes to study the conformation distributions of cytidine (5'-CMP), adenosine (5'-AMP), and inosine (5'-IMP) in acidic aqueous solutions. The experimental data of pseudo-contact shift together with the data of spin-lattice relaxation rate as well as spin-coupling constants of ¹H spectra were processed by computer. The results show that in aqueous solutions the conformations of the nucleotides exist in equilibrium as a group of conformers. In comparison with crystalline state, the dihedral angles around single bonds and the puckering forms of ribose ring have changed to some extent. However, the base groups are still in anti-forms