Formation mechanism of yolk-shell LaMnO3 microspheres prepared by P123-template and oxidation of NO

The yolk-shell LaMnO3 perovskite microspheres were fabricated by a novel,simple and mild soft template approach.A series of template-P123 concentrations(0-6.12 mmol·L^-1)were employed to optimize the most complete spheres.When the concentration of P123 is 3.0 mmol·L^-1,the obtained yolk-shell microspheres with a diameter of 200-700 nm were constructed by nanoparticles.The possible formation mechanism of the yolk-shell microspheres was revealed step by step via XRD,SEM,TEM,EDS and HRTEM.Molecules of P123 were suitably mixed with solvents for double shelled vesicles through self-assembly,which interacted with metal complexes to form P123-metal vesicles.After the removal of P123 and citric acid by calcination at 700 ℃,the yolk-shell LaMnO3 microspheres with through-channels were obtained.Through-channels on the surface were due to citric acid and the solid core was attributed to the shrink of inner vesicles.Prepared yolk-shell microsphere samples possessed a larger surface area and a higher maximum NO conversion value of 78% at 314 ℃ for NO oxidation,compared with samples without the yolk-shell structure.

Optical properties of Zn-diffused InP layers for the planar-type InGaAs/InP photodetectors

Zn diffusion into InP was carried out ex-situ using a new Zn diffusion technique with zinc phosphorus particles placed around InP materials as zinc source in a semi-closed chamber formed by a modified diffusion furnace. The optical characteristics of the Zn-diffused InP layer for the planar-type InGaAs/InP PIN photodetectors grown by molecular beam epitaxy （MBE） has been investigated by photoluminescence （PL） measurements. The temperature-dependent PL spectrum of Zn-diffused InP samples at different diffusion temperatures showed that band-to-acceptor transition dominates the PL emission, which indicates that Zn was commendably diffused into InP layer as the acceptor. High quality Zn-diffused InP layer with typically smooth surface was obtained at 580 ℃for 10 min. Furthermore, more interstitial Zn atoms were activated to act as acceptors after a rapid annealing process. Based on the above Zn-diffusion technique, a 50μm planar-type InGaAs/InP PIN photodector device was fabricated and exhibited a low dark current of 7.73 pA under a reverse bias potential of -5 V and a high break- down voltage of larger than 41 V （1 〈 10μA）. In addition, a high responsivity of 0.81 A/W at 1.31/~m and 0.97 A/W at 1.55μm was obtained in the developed PIN photodetector.

Symplastic communication in the root cap directs auxin distribution to modulate root development

Root cap not only protects root meristem,but also detects and transduces the signals of environmental changes to affect root development.The symplastic communication is an important way for plants to transduce signals to coordinate the development and physiology in response to the changing enviroments.However,it is unclear how the symplastic communication between root cap cells affects root growth.Here we exploit an inducible system to specifically block the symplastic communication in the root cap.Transient blockage of plasmodesmata(PD)in differentiated collumella cells severely impairs the root development in Arabidopsis,in particular in the stem cell niche and the proximal meristem.The neighboring stem cell niche is the region that is most sensitive to the disrupted symplastic communication and responds rapidly via the alteration of auxin distribution.In the later stage,the cell division in proximal meristem is inhibited,presumably due to the reduced auxin level in the root cap.Our results reveal the essential role of the differentiated collumella cells in the root cap mediated signaling system that directs root development.