Co_(3)O_(4)/Mn_(3)O_(4) hybrid catalysts with heterointerfaces as bifunctional catalysts for Zn-air batteries

Zinc-air batteries(ZABs) with high energy density and safety are promising as next-generation energy storage systems, while their applications are severely hindered by the sluggish reaction kinetic of air cathodes. Developing a bifunctional catalyst with high activity and durability is an effective strategy to address the above challenges. Herein, a Co_(3)O_(4)/Mn_(3)O_(4) nanohybrid with heterointerfaces is designed as advanced cathode catalyst for ZABs. Density functional theory calculations show the heterogeneous interface between Co_(3)O_(4)/Mn_(3)O_(4) can improve the dynamics of carrier transport and thus enhancing the catalytic activity and durability. The Co_(3)O_(4)/Mn_(3)O_(4) catalyst anchored on reduced graphene oxide(rGO)exhibits high oxygen reduction reaction(ORR) activity with a half-wave potential of 0.86 V, and excellent oxygen evolution reaction(OER) activity with the potential of 1.59 V at 10 mA cm^(-2) , which are comparable to the commercial noble metal catalysts. The improved ORR/OER catalytic activity is ascribed to the synergistic effect of heterointerfaces between Co_(3)O_(4) and Mn_(3)O_(4)as well as the improved conductivity and contact area of oxygen/catalysts/electrolytes three-phase interface by r GO. Furthermore, a home-made ZAB based on Co_(3)O_(4)/Mn_(3)O_(4)/r GO shows a high open circuit voltage of 1.54 V, a large power density of 194.6 mW cm^(-2) and good long-term cycling stability of nearly 400 h at 5 mA cm^(-2) , which affords a promising bifunctional oxygen catalyst for rechargeable ZABs.

A chromosome-level genome assembly of anesthetic drug–producing Anisodus acutangulus provides insights into its evolution and the biosynthesis of tropane alkaloids

Tropane alkaloids(TAs),which are anticholinergic agents,are an essential class of natural compounds,and there is a growing demand for TAs with anesthetic,analgesic,and spasmolytic effects.Anisodus acutan-gulus(Solanaceae)is a TA-producing plant that was used as an anesthetic in ancient China.In this study,we assembled a high-quality,chromosome-scale genome of A.acutangulus with a contig N50 of 7.4 Mb.A recent whole-genome duplication occurred in A.acutangulus after its divergence from other Solanaceae species,which resulted in the duplication of ADC1 and UGT genes involved in TA biosynthesis.The catalytic activities of H6H enzymes were determined for three Solanaceae plants.On the basis of evolution and co-expressed genes,AaWRKY11 was selected for further analyses,which revealed that its encoded tran-scription factor promotes TA biosynthesis by activating AaH6H1 expression.Thesefindings provide useful insights into genome evolution related to TA biosynthesis and have potential implications for genetic manipulation of TA-producing plants.

Thermally enhanced responsivity in an all-silicon optical power monitor based on defect-mediated absorption

We demonstrate a high responsivity all-silicon in-line optical power monitor by using the thermal effect to enhance the quantum efficiency of defect-mediated absorption at 1550 nm.The doping compensation technique is utilized to increase the density of lattice defects responsible for the sub-bandgap absorption and suppress the detrimental free carrier absorption.The 200-μm-long device presents a propagation loss as low as 2.9 d B/cm.Its responsivity is enhanced from 12.1 m A/W to 112 m A/W at-9 V bias by heating the optical absorption region.With this device,we build an optical power monitoring system that operates in the sampling mode.The minimal detectable optical power of the system is below-22.8 d Bm,while the average power consumption is less than1 m W at a sampling frequency of 10 Hz.Advantages of this scheme in terms of high responsivity,low insertion loss,and low power consumption lend itself to implement the feedback control of advanced large-scale silicon photonic integrated circuits.

High sideband suppression silicon single sideband modulator integrated with a radio frequency branch line coupler

We demonstrate a single-chip silicon optical single sideband (OSSB) modulator composed of a radio frequenc(RF) branch line coupler (BLC) and a silicon dual-parallel Mach–Zehnder modulator (DP-MZM).A co-design between the BLC and the DP-MZM is implemented to improve the sideband suppression ratio (SSR).The modu lator has a modulation efficiency of V_(π)L_(π)~1.75 V·cm and a 3 dB electro-optical (EO) bandwidth of 48.7 GHz The BLC can generate a pair of RF signals with equal amplitudes and orthogonal phases at the optimal frequenc of 21 GHz.We prove through theoretical calculation and experiment that,although the BLC’s performance in terms of power balance and phase orthogonality deteriorates in a wider frequency range,high SSRs can be realized by adjusting relevant bias phases of the DP-MZM.With this technique,the undesired sidebands are completel suppressed below the noise floor in the frequency range from 15 GHz to 30 GHz when the chip operates in the ful carrier OSSB (FC-OSSB) mode.In addition,an SSR>35 dB and an carrier suppression ratio (CSR)>42 dB ar demonstrated at 21 GHz in the suppressed carrier OSSB (SC-OSSB) mode.

The Complete Chloroplast Genome Sequences of Anisodus Acutangulus and a Comparison with Other Solanaceae Species

Background:Anisodus acutangulus(Solanaceae),an important folk medicinal herb in China,produces up to 1.2%alkaloids more than that in other Solanaceae plants such as Hyoscyamus niger,while its evolutionary position in Hyoscyameae is not very clear.Objective:To explain the evolutionary position of A.acutangulus in the Solanaceae via complete chloroplast genome(cp)sequence.Methods:Complete chloroplast genome of A.acutangulus was obtained and characterized using the Illumina PE150 pair-end sequencing data.Structure of the genome,codon usage,nucleotide variability(Pi)value,distribution of repeats and SSRs between A.acutangulus and other seven Solanaceae species were analyzed.Previously published 22 Solanaceae cp genomes were used to construct phylogenetic tree.Results:The complete cp genome of A.acutangulus is 156082 bp in length,showed the typical quadripartite structure.The complete cp genome of A.acutangulus was highly conserved.A total of 112 unique genes were found in cp genome of A.acutangulus,among which 17 were duplicated.Further,we found eight hotspot regions for genome divergence could be explored as new DNA barcodes for the identification of the Solanaceae species.Phylogenetic analysis showed that A.acutangulus formed a clade with H.niger.Conclusion:A.acutangulus belongs to Hyoscyameae subfamily and the complete cp genome provides valuable information for phylogenetic reconstruction or comparative genomics of A.acutangulus.