A Novel Hierarchical Porous 3D Structured Vanadium Nitride/Carbon Membranes for High-performance Supercapacitor Negative Electrodes

Transition-metal nitrides exhibit wide potential windows and good electrochemical performance, but usually experience imbalanced practical applications in the energy storage field due to aggregation, poor circulation stability, and complicated syntheses. In this study, a novel and simple multiphase polymeric strategy was developed to fabricate hybrid vanadium nitride/carbon(VN/C) membranes for supercapacitor negative electrodes, in which VN nanoparticles were uniformly distributed in the hierarchical porous carbon 3D networks. The supercapacitor negative electrode based on VN/C membranes exhibited a high specific capacitance of 392.0 F g^(-1) at 0.5 A g^(-1) and an excellent rate capability with capacitance retention of 50.5% at 30 A g^(-1). For the asymmetric device fabricated using Ni(OH)_2//VN/C membranes, a high energy density of 43.0 Wh kg^(-1) at a power density of800 W kg^(-1) was observed. Moreover, the device also showed good cycling stability of 82.9% at a current density of 1.0 A g^(-1) after 8000 cycles. This work may throw a light on simply the fabrication of other high-performance transition-metal nitridebased supercapacitor or other energy storage devices.

Novel Hybrid Nanoparticles of Vanadium Nitride/Porous Carbon as an Anode Material for Symmetrical Supercapacitor

Hybrid materials of vanadium nitride and porous carbon nanoparticles(VN/PCNPs) were fabricated by a facile pyrolysis process of vanadium pentoxide(V_2O_5) xerogel and melamine at relatively low temperature of 800 °C for supercapacitor application. The effects of the feed ratio of V_2O_5 to melamine(r), and nitrogen flow rate on the microstructure and electrochemical performance were also investigated. It was found that the size of the as-synthesized nanoparticles is about 20 nm. Both r value and N_2 flow rate have enormous impacts on morphology and microstructure of the nanoparticle, which correspondingly determined the electrochemical performance of the material. The VN/C hybrid nanoparticles exhibited high capacitive properties, and a maximum specific capacitance of 255.0 Fg^(-1) was achieved at a current density of 1.0 Ag^(-1) in 2 M KOH aqueous electrolyte and the potential range from 0 to -1.15 V. In addition,symmetrical supercapacitor fabricated with the as-synthesized VN/PCNPs presents a high specific capacitance of 43.5 F g^(-1) at 0.5 A g^(-1) based on the entire cell, and an energy density of 8.0 Wh kg^(-1) when the power density was 575 W kg^(-1). Even when the power density increased to 2831.5 W kg^(-1), the energy density still remained 6.1 Wh kg^(-1).

Neutron irradiation-induced effects on the reliability performance of electrochemical metallization memory devices

In this work,electrochemical metallization memory(ECM)devices with an Ag/AgInSbTe(AIST)/amorphous carbon(a-C)/Pt structure were irradiated with 14 MeV neutrons.The switching reliability performance before and after neutron irradiation was compared and analyzed in detail.The results show that the irradiated memory cells functioned properly,and the initial resistance,the resistance at the low-resistance state(LRS),the RESET voltage and the data retention performance showed little degradation even when the total neutron fluence was as high as 2.5×1011 n/cm2.Other switching characteristics such as the forming voltage,the resistance at the high-resistance state(HRS),and the SET voltage were also studied,all of which merely showed a slight parameter drift.Irradiation-induced Ag ions doping of the a-C layer is proposed to explain the damaging effects of neutron irradiation.The excellent hard characteristics of these Ag/AIST/a-C/Pt-based ECM devices suggest potential beneficial applications in the aerospace and nuclear industries.

Voltage-dependent plasticity and image Boolean operations realized in a WOx-based memristive synapse

The development of electronic devices that possess the functionality of biological synapses is a crucial step towards neuromorphic computing.In this work,we present a WOx-based memristive device that can emulate voltage-dependent synaptic plasticity.By adjusting the amplitude of the applied voltage,we were able to reproduce short-term plasticity(STP)and the transition from STP to long-term potentiation.The stimulation with high intensity induced long-term enhancement of conductance without any decay process,thus representing a permanent memory behavior.Moreover,the image Boolean operations(including intersection,subtraction,and union)were also demonstrated in the memristive synapse array based on the above voltage-dependent plasticity.The experimental achievements of this study provide a new insight into the successful mimicry of essential characteristics of synaptic behaviors.

Emerging multimodal memristors for biorealistic neuromorphic applications

The integration of sensory information from different modalities,such as touch and vision,is essential for organisms to perform behavioral functions such as decision-making,learning,and memory.Artificial implementation of human multi-sensory perception using electronic supports is of great significance for achieving efficient human–machine interaction.Thanks to their structural and functional similarity with biological synapses,memristors are emerging as promising nanodevices for developing artificial neuromorphic perception.Memristive devices can sense multidimensional signals including light,pressure,and sound.Their in-sensor computing architecture represents an ideal platform for efficient multimodal perception.We review recent progress in multimodal memristive technology and its application to neuromorphic perception of complex stimuli carrying visual,olfactory,auditory,and tactile information.At the device level,the operation model and undergoing mechanism have also been introduced.Finally,we discuss the challenges and prospects associated with this rapidly progressing field of research.

Neglected Aspects of SARS-CoV-2 Aerosol Transmission in Bathrooms of Multistory and High-Rise Buildings—Beijing Municipality,China,October 2022

Summary What is already known about this topic?There is a toilet flush-soil stack-floor drain pathway of aerosol transmission in multistory and high-rise buildings,but the influencing factors are not completely clear.What is added by this report?The poor airtightness of the connecting parts of the floor drain,as well as pressure fluctuations in the sewage pipe during toilet flushing caused by blockage of the soil stack vent,may lead to the cross-floor transmission of viral aerosols through the soil stack and floor drains.

Utilization of Transthoracic Echocardiography Is Associated with a Decreased 6-month Readmission Rate in Hospitalized Heart Failure:A Propensity Score-matched Analysis

Objective::Repeated hospitalization due to congestion is a characteristic of the whole course of heart failure.Echocardiography can be used to assess cardiac function and volume status.However,whether echocardiography can reduce the rehospitalization rate remains unclear.This study aimed to evaluate the impact of transthoracic echocardiography(TTE)use on readmission rates in hospitalized patients with heart failure.Methods::The study was based on the Zigong heart failure database,which contained information on 2,008 adult patients with heart failure admitted to the Zigong Fourth People’s Hospital(Sichuan Province,China)from December 2016 to June 2019.Patients were divided into 2 groups according to the usage of TTE on the day of hospital admission(TTE group(1,371 patients)and no TTE group(637 patients),respectively).The primary outcome was the 6-month readmission rate.The statistical approaches used included multivariate Cox regression,propensity score analysis,and an inverse probability weighting model to ensure the robustness of the findings.Results::A significant reduction in 6-month readmission rate was observed among the TTE group compared with the no TTE group(hazard ratio=0.60,95%confidence interval(CI)=0.52-0.69,P<0.001).The frequencies of intravenous nitrates,diuretics,and inotropes during hospitalization were significantly higher in the TTE group compared with those in the no TTE group(10.9%vs.8.3%,88.5%vs.86.2%,and 66.9%vs.65.6%,respectively,all P<0.001).The proportion of patients returning to the emergency department within 6 months was significantly lower in the TTE group compared with the no TTE group(35.6%vs.50.3%,P<0.001).Conclusions::Utilization of TEE on admission day was associated with a reduced 6-month readmission rate in hospitalized patients with heart failure.

Advances in memristor based artificial neuron fabrication-materials,models,and applications

Spiking neural network(SNN),widely known as the third-generation neural network,has been frequently investigated due to its excellent spatiotemporal information processing capability,high biological plausibility,and low energy consumption characteristics.Analogous to the working mechanism of human brain,the SNN system transmits information through the spiking action of neurons.Therefore,artificial neurons are critical building blocks for constructing SNN in hardware.Memristors are drawing growing attention due to low consumption,high speed,and nonlinearity characteristics,which are recently introduced to mimic the functions of biological neurons.Researchers have proposed multifarious memristive materials including organic materials,inorganic materials,or even two-dimensional materials.Taking advantage of the unique electrical behavior of these materials,several neuron models are successfully implemented,such as Hodgkin–Huxley model,leaky integrate-and-fire model and integrate-and-fire model.In this review,the recent reports of artificial neurons based on memristive devices are discussed.In addition,we highlight the models and applications through combining artificial neuronal devices with sensors or other electronic devices.Finally,the future challenges and outlooks of memristor-based artificial neurons are discussed,and the development of hardware implementation of brain-like intelligence system based on SNN is also prospected.

Memristors with organic-inorganic halide perovskites

Organic-inorganic halide perovskites(OHPs)have been intensively studied for application in solar cells with high conversion efficiency exceeding 22%.The unique electrical and optical properties of OHPs have led to their use in optoelectronic device applications beyond photovoltaics,such as light-emitting diodes,photodetectors,transistors.New information storage technologies and computing architectures are being researched extensively with the aim of addressing the growing challenge of approaching end of Moore's law and von Neumann bottleneck.As the fourth basic circuit element,memristor is a leading candidate with powerful capabilities in information storage and neuromorphic computing applications.Recently,OHPs have received growing attention as promising materials for memristors.In particular,their mixed ionic-electronic conduction ability paired with light sensitivity provide OHPs with the opportunity to display novel functions such as optical-erase memory,optogenetics-inspired synaptic functions,and lightaccelerated learning capability.This review covers recent advances in OHP-based memristors development including memristive mechanism and analytical models,universal memristive characteristics for memory and neuromorphic computing applications,and novel multi-functionalization.Challenges and future prospects of OHP-based memristors are also discussed.

Human and climatic drivers of land and water use from 1997 to 2019 in Tarim River basin,China

Climate and human activities change spatial and temporal distribution of water and land use.The Tarim River,the largest inland river in China,faced a long-term exploitation of land and water over a rapid economic development.We analyzed land and water use from 1997 to 2019 in Tarim River Basin by Landsat images,and data on hydrology,climate,population,economy and PM_(2.5)(air particulate matter≤2.5μm).Agricultural land expanded the fastest(4-11%),followed by natural vegetation(15-16%)and water area(4-5%)with population and economic increase.Air quality(PM_(2.5)μg m^(−3))improved in upper(62-27)and middle(48-17)reaches.The water area in lower increase 5%because of ecological water delivery since 2000.Land use in the lower reach was dominated by agriculture,where the downstream runoff consumption increased by 6.8 times.The average annual air temperature and precipitation gradually increased by 0.5℃and 51 mm in source and 0.9℃and 30 mm in main reaches.The average annual water consumption in upper and middle reaches was 4×10^(9)m^(3),accounting for 87%of input runoff in the main reach.Water consumption in middle reach increased by 33 times in 2009-2017.The industry structure was changing from primary to secondary and tertiary industry.To sum up,implementation of water saving strategies and ecological water delivery restored local ecology.Sustainable strategies should be applied facing industrialization.Furthermore,changing the industry structure and restoring the degraded farmlands to grasslands or forests would keep sustainability of Tarim River Basin.

SARS-CoV-2 Aerosol Transmission Through Vertical Sanitary Drains in High-Rise Buildings--Shenzhen,Guangdong Province,China,March 2022

Summary What is already known about this topic?Aerosol transmission of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)via sanitary pipelines in high-rise buildings is possible,however,there is a lack of experimental evidence.

不同社交距离下口罩对气溶胶化新冠病毒替代物的过滤效率

The coronavirus disease 2019(COVID-19)pandemic is an unpreedented global event.It has become clear that COVID-19 is transmitted by virus-containing droplets(>5μm)and aerosols(<5μm),and that all human exhalatory activities(e.g.,breathing,speaking,singing,shouting,coughing,and sneezing)result in the emission of suspended droplets/aerosols of various sizes.As an example,COVID-19 patients exhale millions of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)RNA copies into the air per hour[1].SARS-CoV-2-laden aerosols play a profound role in disease transmission,as they can linger and remain viable in the air for a long duration(~16 h)[2]and travel a long distance(~4.8 m)due to their smaller size[3].