Introduction: Calcium-aluminum–rich inclusions (CAIs) are considered to be the first formed solids in the Solar System [1]. Determining absolute ages of CAIs using long-lived radiochronometers such as PbPb, and relative ages using short-lived radiochronometers such as Al-Mg, is important for establishing the time sequence of early Solar System events. The long lived Pb-Pb chronometer has been u...

The thermal conductivity of superconducting MgB 2 was studied in both the superconducting and normal state region. The latter is almost equally determined by the electronic-and the lattice thermal conductivity. In the superconducting state, however, the lattice thermal conductivity is larger. The electronic thermal conductivity below T c was derived from the experimental data considering the Ba...

Coordinative chain transfer polymerization (CCTP) has opened a new path for the development of novel products like olefin block copolymers and chain-end functional polyolefins. However, conflicting results are frequently reported on the catalyst performance including activity and comonomer selectivity under CCTP conditions. Here we have selected two catalysts including rac-ethylenebis(1-η5-inde...

Previous work in Arabidopsis showed that after an ancient tetraploidy event, genes were preferentially removed from one of the two homologs, a process known as fractionation. The mechanism of fractionation is unknown. We sought to determine whether such preferential, or biased, fractionation exists in maize and, if so, whether a specific mechanism could be implicated in this process. We studied...

Carbon isotope fractionation factors associated with the aerobic consumption of methane (C1), ethane (C2), propane (C3), and nbutane (C4) were determined from incubations of marine sediment collected from the Coal Oil Point hydrocarbon seep field, located offshore Santa Barbara, CA. Hydrogen isotope fractionation factors for C1, C2 and C3 were determined concurrently. Fresh sediment samples fro...

Studies of microbial sulfate reduction have suggested that the magnitude of sulfur isotope fractionation varies with sulfate concentration. Small apparent sulfur isotope fractionations preserved in Archean rocks have been interpreted as suggesting Archean sulfate concentrations of <200 μm, while larger fractionations thereafter have been interpreted to require higher concentrations. In this wor...