Intermetallic Nix My (M = Ga and Sn) nanocrystals with uniform particle size and controlled composition are successfully synthesized via a solution-based co-reduction strategy. The as-obtained nanocrystals are crystalline and structurally ordered. The active-site isolation and modified electronic structure are responsible for the excellent catalytic performance for alkyne semi-hydrogenation of the as-obtained non-precious catalysts.

It is still a major challenge for preparing semiconductor nanocrysals with controllable size, shape, and doping. Especially, the size of nanoparticles under 10 nm still remains a big challenge. To date, there are very few researches of the synthesis of SnO 2 nanocrystals by using biomolecule-assisted hydrothermal approach. SnO 2 is an n-type semiconductor with the free exciton Bohr radius of 2.7 nm. The degradation of rhodamine B (RhB), an organic dye, in aqueous suspension is selected as a probe reaction to evaluate the catalytic activity of semiconductor photocatalytic performance. Herein, we report a biomolecule-assisted hydrothermal route for generating SnO 2 with diameters <10 nm, which presents excellent photocatalytic degradation of RhB. Under the basic condition, the degradation of RhB is close to 100% within 150 min. The high degradation rate of RhB on the as-synthesized SnO 2 nanocrystals can be attributed to the small size. The degradation mechanism is also discussed.

International audienceThis paper reviews recent progress in the development of the Beijing Climate Center Climate System Model (BCC_CSM) and its four component models (atmosphere, land surface, ocean, and sea ice). Two recent versions are described: BCC_CSM1.1 with coarse resolution (approximately 2.8125°×2.8125°) and BCC_CSM1.1(m) with moderate resolution (approximately 1.125°×1.125°). Both versions are fully coupled climate-carbon cycle models that simulate the global terrestrial and oceanic carbon cycles and include dynamic vegetation. Both models well simulate the concentration and temporal evolution of atmospheric CO2 during the 20th century with anthropogenic CO2 emissions prescribed. Simulations using these two versions of the BCC_CSM model have been contributed to the Coupled Model Intercomparison Project phase five (CMIP5) in support of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). These simulations are available for use by both national and international communities for investigating global climate change and for future climate projections.Simulations of the 20th century climate using BCC_CSM1.1 and BCC_CSM1.1(m) are presented and validated, with particular focus on the spatial pattern and seasonal evolution of precipitation and surface air temperature on global and continental scales. Simulations of climate during the last millennium and projections of climate change during the next century are also presented and discussed. Both BCC_CSM1.1 and BCC_CSM1.1(m) perform well when compared with other CMIP5 models. Preliminary analyses indicate that the higher resolution in BCC_CSM1.1(m) improves the simulation of mean climate relative to BCC_CSM1.1, particularly on regional scales

Composite Bi@Bi 2 O 3 microspheres have been synthesized via a microwave-assisted solvothermal route. The Bi@Bi 2 O 3 microspheres had a narrow size distribution in the range 1.2-2.8 mm. Glucose was selected as the reductant, BiCl 3 as the bismuth source, and ethylene glycol (EG) as the solvent in the synthesis system. The as-synthesized sample was characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle diameter distribution, energy dispersive X-ray spectroscopy (EDS), ultraviolet-visible (UV-vis) spectroscopy, and photoluminescence (PL) spectroscopy. The photocatalytic activities of the Bi@Bi 2 O 3 microspheres were evaluated by the photodegradation of rhodamine B (RhB) and methyl orange (MO) dyes under UV light irradiation. The degradation reached ~96.6% for RhB and 100% for MO after 4 h reaction in the presence of the as-synthesized Bi@Bi 2 O 3 microspheres.