Development of advanced anion exchange membrane from the view of the performance of water electrolysis cell

Green hydrogen produced by water electrolysis combined with renewable energy is a promising alternative to fossil fuels due to its high energy density with zero-carbon emissions.Among water electrolysis technologies,the anion exchange membrane(AEM) water electrolysis has gained intensive attention and is considered as the next-generation emerging technology due to its potential advantages,such as the use of low-cost non-noble metal catalysts,the relatively mature stack assembly process,etc.However,the AEM water electrolyzer is still in the early development stage of the kW-level stack,which is mainly attributed to severe performance decay caused by the core component,i.e.,AEM.Here,the review comprehensively presents the recent progress of advanced AEM from the view of the performance of water electrolysis cells.Herein,fundamental principles and critical components of AEM water electrolyzers are introduced,and work conditions of AEM water electrolyzers and AEM performance improvement strategies are discussed.The challenges and perspectives are also analyzed.

Design of ZnSe-CoSe heterostructure decorated in hollow N-doped carbon nanocage with generous adsorption and catalysis sites for the reversibly fast kinetics of polysulfide conversion

Although lithium-sulfur batteries(Li SBs)are regarded as one of the most promising candidates for the next-generation energy storage system,the actual industrial application is hindered by the sluggish solid–liquid phase conversion kinetics,severe shuttle effect,and low sulfur loadings.Herein,a zeolitic imidazolate framework(ZIF)derived heterogeneous ZnSe-CoSe nanoparticles encapsulated in hollow N-doped carbon nanocage(ZnSe-CoSe-HNC)was designed by etching with tannic acid as a multifunctional electrocatalyst to boost the polysulfide conversion kinetics in LiSBs.The hollow structure in ZIF ensures large inner voids for sulfur and buffering volume expansions.Abundant exposed ZnSe-CoSe heterogeneous interfaces serve as bifunctional adsorption-catalytic centers to accelerate the conversion kinetics and alleviate the shuttle effect.Together with the highly conductive framework,the ZnSe-CoSeHNC/S cathode exhibits a high initial reversible capacity of 1305.3 m A h g-1at 0.2 C,high-rate capability,and reliable cycling stability under high sulfur loading and lean electrolyte(maintaining at 745 m A h g-1after 200 cycles with a high sulfur loading of 6.4 mg cm-2and a low electrolyte/sulfur ratio of 6μL mg^(-1)).Theoretical calculations have demonstrated the heterostructures of ZnSe-CoSe offer higher binding energy to lithium polysulfides than that of ZnSe or CoSe,facilitating the electron transfer to lithium polysulfides.This work provides a novel heterostructure with superior catalytic ability and hollow conductive architecture,paving the way for the practical application of functional sulfur electrodes.

基于Diels-Alder反应的聚丙烯回收强化

文中采用反应性加工方法将Diels-Alder(D-A)动态共价键接枝到商品化的等规聚丙烯中,在螺杆挤出机中一步法制备出具有热可逆交联结构的聚丙烯,并详细研究了接枝单体浓度、马来酰亚胺与呋喃基团比例等关键参数对交联聚丙烯力学性能的影响,特别是材料循环再利用时的性能变化规律。结果表明,可逆交联能够显著提高聚丙烯的弯曲模量和弯曲强度,材料的冲击强度也有一定改善;当接枝于聚丙烯侧基的呋喃适当过量于小分子交联剂双马来酰亚胺(即马来酰亚胺与呋喃官能团摩尔比为0.50)时,材料的增强效果最优。可逆交联聚丙烯经循环加工2次后,其力学强度仍优于未交联的商品化聚丙烯。此外,得益于D-A反应的热可逆性,交联聚丙烯具有与商品化聚丙烯相近的熔融加工性能。动态共价键的引入为聚丙烯的回收强化提供了新思路。

Risk assessment on the epidemics of human infection with a novel avian influenza A (H7N9) virus in Jiangsu Province, China

A novel avian influenza A （H7N9） virus was discovered in February 2013 in China and has resulted in more than 100 comfirmed human infections including 26 fatal cases as of May 2, 2013. The situation raises many ur- gent questions and global public health concerns. In this study, epidemiologic characteristics of infected human cases in Jiangsu province were analyzed and risk assessment was undertaken based on the information available. Briefly, it is highly unlikely that a pandemic of human infection with avian influenza A （HTN9） virus will happen in Jiangsu Province in the near future. Iia the end, some measures are recommended to prevent the situation from becoming worse.

AI Enlightens Wireless Communication:Analyses,Solutions and Opportunities on CSI Feedback

In this paper,we give a systematic description of the 1st Wireless Communication Artificial Intelligence(AI)Competition(WAIC)which is hosted by IMT-2020(5G)Promotion Group 5G+AI Work Group.Firstly,the framework of full channel state information(F-CSI)feedback problem and its corresponding channel dataset are provided.Then the enhancing schemes for DL-based F-CSI feedback including i)channel data analysis and preprocessing,ii)neural network design and iii)quantization enhancement are elaborated.The final competition results composed of different enhancing schemes are presented.Based on the valuable experience of 1stWAIC,we also list some challenges and potential study areas for the design of AI-based wireless communication systems.

Effects of closing and reopening live poultry markets on the epidemic of human infection with avian influenza A virus

Live poultry markets（LPMs） are crucial places for human infection of influenza A（H7N9 virus）.In Yangtze River Delta,LPMs were closed after the outbreak of human infection with avian influenza A（H7N9） virus,and then reopened when no case was found.Our purpose was to quantify the effect of LPMs＇ operations in this region on the transmission of influenza A（H7N9） virus.We obtained information about dates of symptom onset and locations for all human influenza A（H7N9） cases reported from Shanghai,Jiangsu and Zhejiang provinces by May 31,2014,and acquired dates of closures and reopening of LPMs from official media.A two-phase Bayesian model was fitted by Markov Chain Monte Carlo methods to process the spatial and temporal influence of human cases.A total of 235 cases of influenza A（H7N9） were confirmed in Shanghai,Jiangsu and Zhejiang by May 31,2014.Using these data,our analysis showed that,after LPM closures,the influenza A（H7N9） outbreak disappeared within two weeks in Shanghai,one week in Jiangsu,and one week in Zhejiang,respectively.Local authorities reopened LPMs when there was no outbreak of influenza A（H7N9）,which did not lead to reemergence of human influenza A（H7N9）.LPM closures were effective in controlling the H7N9 outbreak.Reopening of LPM in summer did not increase the risk of human infection with H7N9.Our findings showed that LPMs should be closed immediately in areas where the H7N9 virus is confirmed in LPM.When there is no outbreak of H7N9 virus,LPMs can be reopened to satisfy the Chinese traditional culture of buying live poultry.In the long term,local authorities should take a cautious attitude in permanent LPM closure.

The Geochemical Characteristics of Stable Carbon and Oxygen Isotope and Analysis of Diagenetic Environment --A Case Study of Upper Permian Changxing Formation Dolostone in Northeast of Sichuan

四川盆地东北部上二叠统长兴组白云岩为重要的优质储层,近年来,长兴组白云岩成岩环境或成因问题成为研究者讨论的热点话题。在岩石学研究的基础上,运用稳定碳、氧同位素,对研究区长兴组白云岩进行综合研究表明,白云石化具有多期次的特点,按照成岩环境划分为蒸发环境下的准同生白云岩和埋藏条件下的早、中、晚期成岩白云岩。并划分为早、中、晚成岩阶段,结合碳、氧同位素分析结果进一步表明晚成岩阶段白云岩是构造热液白云石化的结果。

Deep-elliptical-silver-nanowell arrays (d-EAgNWAs) fabricated by stretchable imprinting combining colloidal lithography: A highly sensitive plasmonic sensing platform

Elliptical metallic nanohole arrays possess much higher transmission and enhanced sensitivity compared with circular nanohole arrays.However,fabricating elliptical metallic nanohole arrays in large area with highly tunable aspect ratio remains a challenge.Herein,a brand-new method combining stretchable imprinting with colloidal lithography is figured out to fabricate deep-elliptical-silver-nanowell arrays (d-EAgNWAs).In this method,large area highly ordered silicon nanopillar arrays fabricated by colloidal lithography were taken as a master to transfer large area polydimethylsiloxane (PDMS) nanohole arrays.Benefit from the high elasticity of PDMS mold,the aspect ratio of d-EAgNWAs achieved can be facilely regulated from 1.7 to 5.0.Through optimization of polarization direction and the structural parameters including nanowell depth,aspect ratio,and hole size,the sensing performance of d-EAgNWAs was finally improved up to 1,414.1 nm/RlU.The best sensing behaved d-EAgNWAs were employed as an immunoassay platform finally to prove their great potential in label-free biosensing.

Enhanced oxidase-like activity of g-C_(3)N_(4) nanosheets supported Pd nanosheets for ratiometric fluorescence detection of acetylcholinesterase activity and its inhibitor

The undesirable enzymatic activity of nanozymes under near neutral p H condition and the traditional single signal output always restrict the analytical application of nanozyme-based biosensors.Herein,graphitic carbon nitride nanosheets supported palladium nanosheets composite (Pd/g-C_(3)N_(4)) with both oxidase-like activity and fluorescent property is synthesized.Notably,Pd/g-C_(3)N_(4)exhibits enhanced oxidase-like activity compared to Pd NSs under p H 7.4.By combining Pd/g-C_(3)N_(4)with o-phenylenediamine(OPD),a ratiometric fluorescence assay for acetylcholinesterase (ACh E) activity detection is developed.Pd/g-C_(3)N_(4)can catalyze oxidation of nonfluorescent OPD to fluorescent oxidized OPD (ox OPD,Em=565nm),which can quench fluorescence of g-C_(3)N_(4)supporter (Em=441 nm) through fluorescence resonance energy transfer (FRET).However,in presence of ACh E,acetylthiocholine can be hydrolyzed into thiocholine,which will block the oxidase-like activity of Pd/g-C_(3)N_(4)and then hamper the FRET process.This ratiometric fluorescence assay is also viable to screen ACh E inhibitor.This work will guide design of ratiometric fluorescence assay based on nanozymes with improved enzymatic activity.

Highly sensitive deep-silver-nanowell arrays （d-AgNWAs） for refractometric sensing

Large-area deep-silver-nanowell arrays （d-AgNWAs） for plasmonic sensing were manufactured by combining colloidal lithography with metal deposition. In contrast to most previous studies, we shed light on the outstanding sensitivity afforded by deep metallic nanowells （up to 400 nm in depth）. Using gold nanohole arrays as a mask, a silicon substrate was etched into deep silicon nanowells, which acted as a template for subsequent Ag deposition, resulting in the formation of d-AgNWAs. Various geometric parameters were separately tailored to study the changes in the optical performance and further optimize the sensing ability of the structure. After several rounds of selection, the best sensing d-AgNWA, which had a Ag thickness of 400 nm, template depth of 400 nm, hole diameter of 504 nm, and period of 1 ~m, was selected. It had a sensitivity of 933 nm.RIU-1, which is substantially higher than those of most common thin metallic nanohole arrays. As a proof of concept, the as-prepared structure was employed as a substrate for an antigen-antibody recognition immunoassay, which indicates its great potential for label-free real-time biosensing.

Highly efficient hydrogen peroxide electrosynthesis on oxidized carbon nanotubes by thermally activated-persulfate

Electrochemical synthesis of hydrogen peroxide(H_(2)O_(2))through two-electron oxygen reduction represents an attractive alternative for on-site H_(2)O_(2) generation.Here,we develop a facile thermally activatedpersulfate approach to obtain oxidized carbon nanotubes(O-CNTs-x,x represents oxidation time)with enhanced H_(2)O_(2) electrosynthesis performance.Electrochemical studies have demonstrated that the optimized O-CNTs-6(i.e.,oxidation time is 6 h)could deliver a sustained high selectivity of around 92%for H_(2)O_(2) over a wide voltage window in 0.1 mol/L KOH and a high H_(2)O_(2) production rate of 296.84 mmol/L g^(-1) cat h^(-1).Compared with pristine CNTs,the enhanced catalytic activity primarily stems from the newly-generated oxygen-containing functional groups and some defects created on the surface of O-CNTs-x.Importantly,the proposed oxidation process is proved to be valid for promoting H_(2)O_(2) electrosynthesis performance of the Ketjen black.This study provides an universal oxidation method to obtain highly active carbon-based catalysts and initiates new opportunities for the exploration of highperformance electrosynthesis H_(2)O_(2) catalysts.

Ag nanoparticle/polymer composite barcode nanorods

We demonstrate a facile method combining colloidal lithography, selective ion-exchange, and the in situ reduction of Ag ions （Ag＋） for the fabrication of multi-segmented barcode nanorods. First, polymer multilayer films were prepared by spin-coating alternating thin films of polystyrene and polyacrylic acid （PAA）, and then multi-segmented polymer nanorods were fabricated via reactive ion etching with colloidal masks. Second, Ag nanoparticles （Ag NPs） were incorporated into the PAA segments by an ion exchange and the in situ reduction of the Ag~. The selective incorporation of the Ag NPs permitted the modification of the specific bars of the nanorods. Lastly, the Ag NP/polymer composite nanorods were released from the substrate to form suspensions for further coding applications. By increasing the number of segments and changing the length of each segment in the nanorods, the coding capacity of nanorods was improved. More importantly, this method can easily realize the density tuning of Ag NPs in different segments of a single nanorod by varying the composition of the PAA segments. We believe that numerous other coded materials can also be obtained, which introduces new approaches for fabricating barcoded nanomaterials.

Impact of COVID-19 Interventions on Respiratory and Intestinal Infectious Disease Notifications-Jiangsu Province,China,2020–2023

Introduction:Many measures implemented to control the coronavirus disease 2019(COVID-19)pandemic have reshaped the epidemic patterns of other infectious diseases.This study estimated the impact of the COVID-19 pandemic on respiratory and intestinal infectious diseases and potential changes following reopening.Methods:The optimal intervention and counterfactual models were selected from the seasonal autoregressive integrated moving average(SARIMA),neural network autoregression(NNAR),and hybrid models based on the minimum mean absolute percentage error(MAPE)in the test set.The relative change rate between the actual notification rate and that predicted by the optimal model was calculated for the entire COVID-19 epidemic prevention period and the“reopening”period.Results:Compared with the predicted notification rate based on the counterfactual model,the total relative change rates for the 9 infectious diseases were−44.24%,respiratory infections(−55.41%),and intestinal infections(−26.59%)during 2020–2022.Compared with the predicted notification rate based on the intervention model,the total relative change rates were+247.98%,respiratory infections(+389.59%),and intestinal infections(+50.46%)in 2023.Among them,the relative increases in influenza(+499.98%)and hand-foot-mouth disease(HFMD)(+70.97%)were significant.Conclusions:Measures taken in Jiangsu Province in response to COVID-19 effectively constrained the spread of respiratory and intestinal infectious diseases.Influenza and HFMD rebounded significantly after the lifting of COVID-19 intervention restrictions.