Nitrogen and sulfur co-doped graphene aerogel with hierarchically porous structure for high-performance supercapacitors

Supercapacitors with unique performance have been widely utilized in many fields. Herein, we report a nitrogen and sulfur co-doped graphene aerogel(N/S-GA-2) prepared using a low toxic precursor for high-performance supercapacitors. The as-obtained material possesses a hierarchically porous structure and a large number of electrochemical active sites. At a current density of 1 Ag^-1, the specific capacitance of the N/S-GA-2 for supercapacitors with the ionic liquid as the electrolyte is 169.4 Fg^-1, and the corresponding energy density is 84.5 Wh kg^-1.At a power density of 8.9 k W kg^-1, the energy density can reach up to 75.7 Wh kg^-1, showing that the N/S-GA-2 has an excellent electrochemical performance. Consequently, the N/S-GA-2 can be used as a promising candidate of electrode materials for supercapacitors with high power density and high energy density.

Recommendations for the Diagnosis and Treatment of Maternal SARS-CoV-2 Infection

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has spread worldwide and threatened human’s health.With the passing of time,the epidemiology of coronavirus disease 2019 evolves and the knowledge of SARS-CoV-2 infection accumulates.To further improve the scientific and standardized diagnosis and treatment of maternal SARS-CoV-2 infection in China,the Chinese Society of Perinatal Medicine of Chinese Medical Association commissioned leading experts to develop the Recommendations for the Diagnosis and Treatment of Maternal SARS-CoV-2 Infection under the guidance of the Maternal and Child Health Department of the National Health Commission.This recommendations includes the epidemiology,diagnosis,management,maternal care,medication treatment,care of birth and newborns,and psychological support associated with maternal SARS-CoV-2 infection.It is hoped that the recommendations will effectively help the clinical management of maternal SARS-CoV-2 infection.

A high-sensitivity MEMS gravimeter with a largedynamic range

Precise measurement of variations in the local gravitational acceleration is valuable for natural hazard forecasting,prospecting,and geophysical studies.Common issues of the present gravimetry technologies include their high cost,high mass,and large volume,which can potentially be solved by micro-electromechanical-system(MEMS)technology.However,the reported MEMS gravimeter does not have a high sensitivity and a large dynamic range comparable with those of the present commercial gravimeters,lowering its practicability and ruling out worldwide deployment.In this paper,we introduce a more practical MEMS gravimeter that has a higher sensitivity of 8μGal/√Hz and a larger dynamic range of 8000 mGal by using an advanced suspension design and a customized optical displacement transducer.The proposed MEMS gravimeter has performed the co-site earth tides measurement with a commercial superconducting gravimeter GWR iGrav with the results showing a correlation coefficient of 0.91.