垃圾气化分析及其对中国实现碳中和与无废城市建设的贡献

气化是实现化学利用碳资源(尤其是煤)生产化学品和燃料的关键工艺.目前,全球拥有超过272套气化装置,主要应用于煤化工,尤其在中国.由于在一个化工厂通过技术集成达到工业规模的集中生产可实现减少二氧化碳排放并促进碳密集型行业的循环经济,如废物管理、化学和交通行业,因此,近年来全球对垃圾气化的兴趣日益浓厚,尤其是那些在煤气化...     

Al-Mn-Ce quasicrystalline composites: Phase formation and mechanical properties

Aluminium-based composites with quasicrystalline particles as reinforcements were synthesized via the powder metallurgy processing route. In order to obtain bulk samples with a nanoscale microstructure most equivalent to that resulting from rapid solidification, powders of Al-Mn-Ce alloys were prepared by pulverization of melt-spun ribbons using a planetary ball mill. Significant differences in the phase formation upon quenching, composite microstructure and thermal stability of the microstructure were found for different alloy compositions. Severe grain growth during the subsequent consolidation by hot extrusion caused the formation of a micrometre-scale composite instead of the nanoscale phase mixture initially existing after rapid solidification. After hot extrusion, the specimens were deformed by compression at a constant compression rate at room temperature. With an ultimate strength of up to 975 MPa and a ductility of more than 4% the material yields excellent properties compared with conventionally produced aluminium-based alloys.     

Facile growth of monolayer MoS<Subscript>2</Subscript> film areas on SiO<Subscript>2</Subscript>

Areas of single-layer MoS₂ film can be prepared in a tube furnace without the need for temperature control. The films were characterized by means of Raman spectroscopy, photoluminescence, low-energy electron diffraction and microscopy, and X-ray photoelectron spectroscopy and mapping. Transport measurements show n-doped material with a mobility of 0.26 cm² V^-1 s^-1.     

Semiconductor-laser amplifier as an optically controlled switch

The application of a semiconductor-laser amplifier with reduced facet reflectivity as all-optical switch is described. An optical data signal is switched on and off with an extinction ratio of 10 dB when an optical control signal is turned on and off. The two optical signals are polarized perpendicularly to each other. The device was operated up to 100 MHz.Nanjing Institute of Posts and Telecommunication Nanjing, PR China