46 research outputs found
A 3-D diamondoid MOF catalyst based on in situ generated [Cu(L)2] N-heterocyclic carbene (NHC) linkers: hydroboration of CO(2)
Includes supplementary informationA new MOF, [Zn4O{Cu(L)2}2] (1), with a 4-fold interpenetrated 3D diamondoid structure was synthesised from in situ generated [Cu(L)2] NHC linkers. MOF 1 possesses tetrahedral Zn4O nodes, which are unusually coordinated by four pairs of carboxylates from four [Cu(L)2] linkers, and 14 A 1-D pore channels lined with [Cu(L)2] moieties that catalyse the hydroboration of CO2.Alexandre Burgun, Rachel S. Crees, Marcus L. Cole, Christian J. Doonan and Christopher J. Sumb
Photoluminescence as Complementary Evidence for Short-Range Order in Ionic Silica Nanoparticle Networks
Suitable thicknesses of base metal and interlayer, and evolution of phases for Ag/Sn/Ag transient liquid-phase joints used for power die attachment
Both real Si insulated gate bipolar transistors (IGBT) with conventional Ni\Ag metallization and a dummy Si die with thickened Ni\Ag metallization have been bonded on Ag foils electroplated with 2.7 m and 6.8 m thick Sn as an interlayer at 250ºC for 0 min, 40 min and 640 min. From microstructure characterization of the resulting joints, suitable thicknesses are suggested for the Ag base metal and the Sn interlayer for Ag/Sn/Ag transient liquid phase (TLP) joints used in power die attachment, and the diffusivities of Ag and Sn in the Ag phase are extracted. In combination with the kinetic constants of Ag3Sn growth and diffusivities of Ag and Sn in Ag reported in the literature, the extracted diffusivities of Ag and Sn in Ag phase are also used to simulate and predict the diffusion-controlled growth and evolution of phases in the Ag/Sn/Ag TLP joints during an extended bonding process and in service
Complex admixture preceded and followed the extinction of wisent in the wild
Retracing complex population processes that precede extreme bottlenecks may be impossible using data from living individuals. The wisent (Bison bonasus), Europe’s largest terrestrial mammal, exemplifies such a population history, having gone extinct in the wild but subsequently restored by captive breeding efforts. Using low coverage genomic data from modern and historical individuals, we investigate population processes occurring before and after this extinction. Analysis of aligned genomes supports the division of wisent into two previously recognized subspecies, but almost half of the genomic alignment contradicts this population history as a result of incomplete lineage sorting and admixture. Admixture between subspecies populations occurred prior to extinction and subsequently during the captive breeding program. Admixture with the Bos cattle lineage is also widespread but results from ancient events rather than recent hybridization with domestics. Our study demonstrates the huge potential of historical genomes for both studying evolutionary histories and for guiding conservation strategies
Breit-Pauli R-matrix calculation of fine-structure effective collision strengths for the electron impact excitation of Mg V
Autonomy: Risk Assessment
Oceanography and ocean observation in general is ever trending toward both automated in situ observation and working in extreme environments. These goals can only be met by de?risking the technology and deployment practices to acceptable levels of risks. A number of industries have standardised risk management processes to support the design and development of their systems. The lack of formal risk assessment of autonomous ocean vehicles has hindered the potential for true autonomy, which is required for exploring unstructured and unexplored environments. When discussing risks different stakeholders may have different consequences foremost in mind. For example the vehicle owner may be interested in risk of loss, whereas the user is interested in risk of vehicle unavailability. Other risks, such as legal risks and risk of collision, affect all stakeholders. This chapter presents a risk management process using several methods tailored to autonomous oceanvehicles in which risk assessment is a key component