Growth of 3,4,9,10-perylenetetracarboxylic-dianhydride (PTCDA) on Cu(110) studied by STM

. The structure of thin 3,4,9,10-perylenetetracarb-oxylic-dianhydride (PTCDA) films on Cu(110) was studied by scanning tunnelling microscopy (STM) from submonolayer to monolayer coverage. While no long-range ordering was found after deposition at room temperature, the formation of a well-defined superstructure is observed after thermal annealing. It appears that the formation of the superstructure is driven by the interaction between the oxygen atoms of the PTCDA and the copper atoms of the substrate. While the distance between the molecules fits well to the atomic lattice of the Cu(110) surface along the [1[`(^[¯])]1^[¯]\bar\Box1\Box]]0] direction, the mismatch along the [001] direction leads to a periodic buckling normal to the surface accompanied by a restructuring of the substrate.     

Particle dynamics in cyclone tribochargers

Triboelectric separation is of increasing importance in a number of industries. The initial tribocharging process is poorly understood, with tribocharger design and operation dominated by trial and error. Better physical understanding of tribocharger operation would be invaluable for the optimization of triboelectric separation processes. Cylindrical pneumatic cyclones are highly suitable for continuous-flow mineral separation applications. Charge measurements, trajectory modelling and high-speed video footage of particle motion have been combined to understand charging in terms of particle dynamics in a cylindrical cyclone. These observations are interpreted in terms of cyclone tribocharger design and operation.     

Juxtaposition of Chemical and Mutation-Induced Developmental Defects in Zebrafish Reveal a Copper-Chelating Activity for Kalihinol F

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Citorellamine,a new bromoindole derivative from polycitorella mariae

The structure of citorellamine, isolated from the tunicate $\text{Polycitorella mariae}$, has been deduced from spectroscopic analyses and chemical transformations.     

The angular distribution of the 12C(γ,pn) reaction for Eγ=120−150 MeV

The angular distribution of nucleons emitted in the ¹²C(γ,pn) reaction has been measured using tagged photons at the Mainz microtron MAMI. The variation of the reaction strength with the polar angles of the two emitted nucleons is reported for E_γ=120−150 MeV. The proton angular distribution peaks at more backward angles than the ²H(γ,p) differential cross section indicating a departure from the simple quasi-deuteron model of 2N photo-emission. The distribution shape is in reasonable agreement with microscopic theoretical models which include both π- and ρ-exchange. Received: 3 September 1997 / Revised version: 17 December 1997     

Iodinated phenethylamine products from a didemnid tunicate

Two idodinated phenethylamine derivatives 1 and 2 were isolated from a didemnid tunicate