Sichuan University

About: Sichuan University is a education organization based out in Chengdu, China. It is known for research contribution in the topics: Population & Catalysis. The organization has 107623 authors who have published 102844 publications receiving 1612131 citations. The organization is also known as: Sìchuān Dàxué.

Gigahertz quantized charge pumping

Abstract: The high-speed, high-accuracy transport of single electrons in nanoscale devices is predicted to underpin future electronics. A key and topical application is the development of a fundamental standard of electrical current linking the ampere to the elementary charge and frequency. For a practical standard, currents at the nanoampere level are required, corresponding to gigahertz transport frequencies. Recent research has concentrated on transport using Coulomb blockade techniques. However, the tunnelling time of the electrons in such devices limits the operation to a few megahertz. We present a different pumping mechanism of single charges, whereby electrons ‘surf’ as particles on a time-dependent potential instead of tunnelling through the barriers as waves. This potential is created by two phase-shifted sinusoidal signals applied directly to metallic finger gates on an etched GaAs/AlGaAs quantum wire. Pumping accurate to better than 10−4, at a frequency up to 3.4 GHz, is reported with this approach.

Facile Route for Synthesizing Ordered Mesoporous Ni–Ce–Al Oxide Materials and Their Catalytic Performance for Methane Dry Reforming to Hydrogen and Syngas

Abstract: A series of ordered mesoporous Ni–Ce–Al composite oxides with various cerium contents were synthesized via a one-pot route: evaporation-induced self-assembly (EISA) strategy and tested in methane dry reforming for hydrogen and synthesis gas production. Using this method, the hydrophobic nickel precursor was directly incorporated into the hydrophobic cores of surfactant micelles, and thus, the highly dispersed Ni nanoparticles were stabilized inside the mesopore channels of an alumina matrix. For comparison, Ni-based catalysts were also prepared by a traditional impregnation method. The characterization results confirmed that the ordered mesostructures were well maintained in all of the cerium-incorporated Ni–Al materials (Ce/(Ce + Al) molar ratio ≤ 3%). The catalyst with a Ce/(Ce + Al) ratio of 1% exhibited the highest catalytic activity (with CO2 and CH4 initial conversions being 70% and 68% at 700 °C, respectively) and remained stable in a methane dry reforming reaction. This improved activity can be at...