All-optical RF spectrum analyzer with a 5 THz bandwidth based on CMOS-compatible high-index doped silica waveguides.

We report an all-optical radio-frequency (RF) spectrum analyzer with a bandwidth greater than 5 THz, based on a 50 cm long spiral waveguide in a CMOS-compatible high-index doped silica platform. By carefully mapping out the dispersion profile of the waveguides for different thicknesses, we identify the optimal design to achieve near-zero dispersion in the C-band. To demonstrate the capability of the RF spectrum analyzer, we measure the optical output of a femtosecond fiber laser with an ultrafast optical RF spectrum in the terahertz regime.

[Microbial degradation of lignocellulose].

Lignocellulose is widely found in the nature. The highly efficient degradation of lignocellulose requires synergistic interactions of varieties of microorganisms. The mechanism of synergistic interaction relationship is not entirely clear because it needs multitudinous microorganisms to participate in the process of lignocellulose degradation.

Biological pretreatment enhances the activity of functional microorganisms and the ability of methanogenesis during anaerobic digestion.

Biological pretreatment can increase the methane production of anaerobic digestion. In this study, stover was pretreated via microbial consortium prior to anaerobic digestion; through 16S rRNA gene and 16S rRNA amplicon sequencing and metatranscriptomic analysis, and the effects of the pretreatment on the microbial community and critical factors of the increased methane production were studied. Microbial community structure was less affected by the pretreatment, which ensures the stable performance of anaerobic digestion.

[Change of bacterial community structure during cellulose degradation by the microbial consortium].

In order to clarify dynamic change of microbial community composition and to identify key functional bacteria in the cellulose degradation consortium, we studied several aspects of the biodegradation of filter papers and rice straws by the microbial consortium, the change of substrate degradation, microbial biomass and pH of fermentation broth. We extracted total DNA of the microbial consortium in different degradation stages for high-throughput sequencing of amplicons of bacterial 16 S rRNA genes. Based on the decomposition characteristics test, we defined the 12th, 72nd and 168th hours after inoculation as the initial stage, peak stage and end stage of degradation, respectively.

Abundance of ammonia-oxidizing bacteria and archaea under different ventilation strategies during cattle manure composting.

Composting of cattle manure was conducted under four ventilation strategies, i.e., no-aeration (A-00), continuous aeration (B-44), non-aeration for 14 d and then aeration for 42 d (C-04), aeration for 14 d and then no-aeration for 42 d (D-40).

In-Situ Generation of Oxide Nanowire Arrays from AgCuZn Alloy Sulfide with Enhanced Electrochemical Oxygen-Evolving Performance.

In this study, AgCuZn sulfide is fabricated on the surface of AgCuZn alloys by hydrothermal sulfuration. This ternary metal sulfide is equipped with enhanced activity toward oxygen evolution reaction (OER) in an alkaline electrolyte. Through comparison of the alloys with diverse compositions, we find out the best electrochemical property of a particular alloy sulfide forming on a AgCuZn substrate (Ag:Cu:Zn=43:49:8).