[en] In the present paper, N,N,N',N'-tetraoctyl diglycolamide (TODGA) as the extractant and n-dodecane as the diluent, the extraction kinetics behavior of Am(III) in TODGA/n-dodecane-HNO₃ system were studied, including stirring speed, the interfacial area, extractant concentration in n-dodecane, extracted ions concentration, acidity of aqueous phase and temperature. The results show that: the extraction process is controlled by diffusion mode under 130 rpm of stirring speed and by chemical reaction mode above 150 rpm. The extraction rate equation and the apparent extraction rate constant of Am(III) by TODGA/n-dodecane in 170 rpm and at 25 °C are followed as: r₀ = d[M]_org./dt ∣∣∣ t=0 = kS/V[Am]_aq.,0^0.94[HNO₃]_aq.,0^1.05[TODGA]_org.,0^1.19 k = (24.17±3.43) x 10^-3 mol^-2.18 L^2.18 min^-1 cm, E_a(Am(III)) = 25.94±0.98kJ/mol. (author)

[en] The removal of minor actinides (mainly Am, Cm and Np) from the high-level waste would remarkably reduce the necessary storage time. Recently developed, a tridentate ligand, N,N,N',N'-tetraoctyl diglycolamide (TODGA), has been identified as one of the most powerful extractants being considered for the partitioning of trivalent actinides and lanthanides. In the present paper, the extraction kinetics behavior of Am(III) in TODGA/n-dodecane-HNO₃ system has been studied, dependent on various parameters such as the stirring speed, the interfacial area, the extractant concentration in n-dodecane, the extracted ions concentration, the acidity of aqueous phase and the temperature. The results show that: the extraction process is controlled by diffusion mode under 130 rpm of stirring speed and by chemical reaction mode above 150 rpm. The extraction rate equation is given in the paper and the apparent extraction rate constant of Am(III) by TODGA/n-dodecane in 170 rpm and at 25 Celsius degrees is k=(24.2±3.4)*10^-3 mol^-2.18*L^2.18*min^-1*cm. The initial extraction rate of Am(III) by TODGA/n-dodecane at 170 r/min and 25 Celsius degrees increases with increasing temperature, and the apparent active energy is calculated to be E_a=(25.94±0.98) kJ/mol

[en] The extraction behavior of U, Np, Pu, Am, rare earth elements and Sr from nitric acid solutions by TODGA/dodecan, DHOA/dodecane and TODGA-DHOA/dodecane were investigated, respectively. Based on experimental results, a separation process was proposed for minor actinide isolation from high level liquid waste (HLLW): the TODGA-DHOA/kerosene system. The multi-stage counter-current cascade experiments were carried out for the purpose by 0.1 mol/l TODGA-1.0 mol/l DHOA/kerosene with miniature mixer- settler contactor rigs (8 stages for extraction, 6 stages for scrubbing, 8 stages for first stripping, 8 stages for second stripping). The results show that the recovery efficiencies of the actinides and lanthanides are more than 99.9%, whereas less than 1% Sr was extracted by 0.1 mol/l TODGA - 1.0 mol/l DHOA/kerosene. The stripping efficiencies of U, Np and Pu are more than 95% in the first stripping step by 0.5 mol/l HNO₃ + 0.5 mol/l AHA(aceto-hydroxamic acid), all of the remained actinides and lanthanides can be stripped by 0.01 mol/l HNO₃ in the second stripping step. 99% Sr was extracted by 0.1 mol/l TODGA/kerosene, so Sr can be recovered efficiently directly from the raffinate by 0.1 mol/l TODGA/kerosene. (authors)

[en] Diffraction-free vectorial elliptic hollow beams (vEHBs) are generated by an optical system composed of a short elliptic hollow fiber (EHF) and an axicon. Each beam has a closed elliptic annular intensity profile and space-varying polarization states in its diffraction-free distance of more than 1 m. The generated beams have a counter-clockwise or clockwise periodically-rotated inhomogeneous polarization. And the spin angular momentum (SAM) of the vEHBs is 1ℏ or –1ℏ which is consistent with the type of dual-mode in the EHF and the periodic polarization rotations of the vEHBs. The vEHBs have potential applications in optically trapping and micromanipulating the micro- or nano-particles, quantum information transmission, and Bose–Einstein condensates, etc. (paper)