Li W.-L.,Tsinghua University |
Li Y.,Tsinghua University |
Xu C.-Q.,Tsinghua University |
Wang X.-B.,PO Box 999 |
And 3 more authors.
Inorganic Chemistry | Year: 2015
Systematic theoretical and experimental investigations have been performed to understand the periodicity, electronic structures, and bonding of gold halides using tetrahalide [AuX4]- anions (X = F, Cl, Br, I, At, Uus). The [AuX4]- (X = Cl, Br, I) anions were experimentally produced in the gas phase, and their negative-ion photoelectron spectra were obtained, exhibiting rich and well-resolved spectral peaks. As expected, Au-X bonds in such series contain generally increasing covalency when halogen ligands become heavier. We calculated the adiabatic electron detachment energies as well as vertical electron detachment energies using density functional theory methods with scalar relativistic and spin-orbit coupling effects. The computationally simulated photoelectron spectra are in good agreement with the experimental ones. Our results show that the trivalent AuIII oxidation state becomes progressively less stable while AuI tends to be preferred when the halides become heavier along the Periodic Table. This series of molecules provides an example for manipulating the oxidation state of metals in complexes through ligand design. © 2015 American Chemical Society.
Steeves T.E.,University of Canterbury |
Holdaway R.N.,University of Canterbury |
Holdaway R.N.,Palaecol Research Ltd |
Hale M.L.,University of Canterbury |
And 6 more authors.
Biology Letters | Year: 2010
Ancient DNA has revolutionized the way in which evolutionary biologists research both extinct and extant taxa, from the inference of evolutionary history to the resolution of taxonomy. Here, we present, to our knowledge, the first study to report the rediscovery of an 'extinct' avian taxon, the Tasman booby (Sula tasmani), using classical palaeontological data combined with ancient and modern DNA data. Contrary to earlier work, we show an overlap in size between fossil and modern birds in the North Tasman Sea (classified currently as S. tasmani and Sula dactylatra fullagari, respectively). In addition, we show that Holocene fossil birds have mitochondrial control region sequences that are identical to those found in modern birds. These results indicate that the Tasman booby is not an extinct taxon: S. dactylatra fullagari O'Brien & Davies, 1990 is therefore a junior synonym of Sula tasmani van Tets, Meredith, Fullagar & Davidson, 1988 and all North Tasman Sea boobies should be known as S. d. tasmani. In addition to reporting the rediscovery of an extinct avian taxon, our study highlights the need for researchers to be cognizant of multidisciplinary approaches to understanding taxonomy and past biodiversity. © 2009 The Royal Society.
Pendoley K.,Pendoley Environmental Pty Ltd |
Christian M.,PO Box 999
Memoirs of the Queensland Museum | Year: 2012
Nothing has been published in the modern literature on the status of marine turtles at Norfolk Island although their presence has been recognised since 1793 (Fidlon & Ryan 1980). This study brings together all the available published, anecdotal and field survey data on marine turtles at Norfolk Island so that the status of habitat usage could be established. The results confirm the Norfolk Island group is used for foraging by resident adult and juvenile Chelonia mydas (Green) turtles and adult Eretmochelys imbricata (Hawksbill) turtles. The natal beaches for these resident animals are thought to be Melanesian and Polynesian islands to the north and the beaches of north eastern Australia. While juvenile hawksbill turtles have not been recorded foraging at Norfolk Island they are the most common species and age class recorded in the island's strandings data. The confirmation of marine turtles at Norfolk means that any future development proposals must include assessment of project impacts on these listed threatened species under Australian Federal legislation and their marine bioregional processes. © Queensland Museum.
Alvine K.J.,PO Box 999 |
Bliss M.,PO Box 999 |
Riley B.J.,PO Box 999 |
Stave J.A.,PO Box 999
Journal of Electronic Materials | Year: 2015
A section of a vertical gradient freeze Cd0.9Zn0.1Te boule approximately 2100 mm3 with a planar area of 300 mm2 was prepared and examined using transmitted infrared microscopy at various magnifications to determine the three-dimensional spatial and size distributions of Te-particles over large longitudinal and radial length scales. Te-particle density distributions were determined as a function of longitudinal and radial positions in these strips and exhibited a multi-modal log-normal size density distribution that indicated a slight preference for increasing size with longitudinal growth time, while showing a pronounced cellular network structure. Higher magnification images revealed a typical Rayleigh-instability pearl string morphology with large and small satellite droplets. This study includes solidification experiments in small crucibles of 30:70 mixtures of Cd:Te performed over a wide range of cooling rates which clearly demonstrated a growth instability with Te-particle capture that is suggested to be responsible for one of the peaks in the size distribution using size discrimination visualization. The results are discussed with regard to a manifold Te-particle genesis history as Te-particle direct capture from melt–solid growth instabilities due to constitutional supercooling and as Te-particle formation from the breakup of Te-ribbons via a Rayleigh–Plateau instability. © 2015 The Minerals, Metals & Materials Society