A new non-fluorinated malonamide-based ionic liquid extractant was synthesized and investigated for the extraction behavior of europium(III) and other trivalent rare-earth ions from nitric acid medium. The extractant was the functionalized ionic liquid trihexyl(tetradecyl)phosphonium N,N,N',N'-tetra(2-ethylhexyl)malonate, [P66614][MA], and it was used in combination with the non-fluorinated ion...

Self-assembled atomic chains can be triggered at stepped Si(111) surfaces by adding sub-monolayer amounts of metals, such as gold, silver, platinum, alkali metals, alkaline earths, and rare earths. A common feature of all these structures is the honeycomb chain, a graphitic strip of Si atoms at the step edge that is lattice matched in the direction parallel to the edge but completely mismatched...

X-ray absorption and magnetization experiments are used to describe the oxidation states of the rare earth ions R=Ce, PI and Tb in the double layer high-Tc superconducting series RBa2Cu307 and Pb2Sr2R1-,CaXCu3O8. We obtained the same oxidation states for the rare earths in these two classes of compounds, namely, R=Ce tetravalent and R=Pr and Tb trivalent.

Here, the state of our knowledge regarding the interior dynamics and evolution of habitable terrestrial planets including Earth and super-Earths is reviewed, and illustrated using state-of-the-art numerical models. Convection of the rocky mantle is the key process that drives the evolution of the interior: it causes plate tectonics, controls heat loss from the metallic core (which generates the...

[1] The discovery of terrestrial-scale extrasolar planets, and their calculated abundance in the galaxy, has prompted speculation on their surface conditions and thermal structure. Both are dependent on the tectonic regime of a planet, which is itself a function of the balance between driving forces, and the resistive strength of the lithosphere. Here we use mantle convection simulations to sho...

The resistivities of various liquid rare earths were calculated in a single-site t-matrix approximation. Good agreement with experiment is achieved. Spin disorder scattering is shown to be unimportant in the liquid state. The experimental resistivity data of liquid rare earths (RE) shows the following behavior [l, 21 : The resistivity p increases across the series of the trivalent RE's. The tem...

We compare two recent astrobiological approaches to the solution of the problem of the “Great Silence” (or Fermi’s paradox): the “rare Earth” hypothesis of Ward and Brownlee, and the phase-transition scenario of Annis. We show that they have important similarities, as far as self-selection of intelligent observers is concerned. In order to better illuminate the differences, we consider the dura...

introduction: nowadays,  considerable developments  in  the field  of  radiotherapy have  been  achieved.  they  include  the  advances  made  in  the  equipments  and  treatment  planning  techniques  which  require  highly complex calculations. such achievements have made it possible to treat cancer patients not only  with  higher  radiation  dose  but  also  with  higher  precision  and  con...