Rising utilization of stable isotopes in tree rings for climate change and forest ecology

Analyses of stable isotopes(C,O,H)in tree rings are increasingly important cross-disciplinary programs.The rapid development in this field documented in an increasing number of publications requires a comprehensive review.This study includes a bibliometric analysis-based review to better understand research trends in tree ring stable isotope research.Overall,1475 publications were selected from the Web of Science Core Collection for 1974-2023.The findings are that:(1)numbers of annual publications and citations increased since 1974.From 1974 to 1980,there were around two relevant publications per year.However,from 2020 to 2022,this rose sharply to 109 publications per year.Likewise,average article citations were less than four per year before 1990,but were around four per article per year after 2000;(2)the major subjects using tree ring stable isotopes include forestry,geosciences,and environmental sciences,contributing to 42.5%of the total during 1974-2023;(3)the top three most productive institutions are the Chinese Academy of Sciences(423),the Swiss Federal Institute for Forest,Snow and Landscape Research(227),and the University of Arizona(204).These achievements result from strong collaborations;(4)review papers,for example,(Dawson et al.,Annu Rev Ecol Syst 33:507-559,2002)and(McCarroll and Loader,Quat Sci Rev 23:771-801,2004),are among the most cited,with more than 1000 citations;(5)tree ring stable isotope studies mainly focus on climatology and ecology,with atmospheric CO_(2) one of the most popular topics.Since 2010,precipitation and drought have received increasing attention.Based on this analysis,the research stages,key findings,debated issues,limitations and direc-tions for future research are summarized.This study serves as an important attempt to understand the progress on the use of stable isotopes in tree rings,providing scientific guid-ance for young researchers in this field.

Comprehensive evaluation of 5G+smart distribution network based on combined weighting method-cloud model

With the large-scale application of 5G technology in smart distribution networks,the operation effects of distribution networks are not clear.Herein,we propose a comprehensive evaluation model of a 5G+smart distribution network based on the combination weighting and cloud model of the improved Fuzzy Analytic Hierarchy-Entropy Weight Method(FAHP-EWM).First,we establish comprehensive evaluation indexes of a 5G+smart distribution network from five dimensions:reliable operation,economic operation,efficient interaction,technological intelligence,and green emission reduction.Second,by introducing the principle of variance minimization,we propose a combined weighting method based on the improved FAHP-EWM to calculate the comprehensive weight,so as to reduce the defects of subjective arbitrariness and promote objectivity.Finally,a comprehensive evaluation model of 5G+smart distribution network based on cloud model is proposed by considering the uncertainty of distribution network node information and equipment status information.The example analysis indicates that the overall operation of the 5G+smart distribution network project is decent,and the weight value calculated by the combined weighting method is more reasonable and accurate than that calculated by the single weighting method,which verifies the effectiveness and rationality of the proposed evaluation method.Moreover,the proposed evaluation method has a certain guiding role for the large-scale application of 5G communication technology in smart distribution networks.

Ferroelectricity of pristine Hf_(0.5)Zr_(0.5)O_(2) films fabricated by atomic layer deposition

Hafnium-based ferroelectric films,remaining their ferroelectricity down to nanoscale thickness,present a promising application for low-power logic devices and nonvolatile memories.It has been appealing for researchers to reduce the required temperature to obtain the ferroelectric phase in hafnium-based ferroelectric films for applications such as flexible and wearable electronics.This work demonstrates that a remanent polarization(P_(r))value of>5μC/cm^(2)can be obtained in asdeposited Hf_(0.5)Zr_(0.5)O_(2)(HZO)films that are fabricated by thermal atomic layer deposition(TALD)under low temperature of 250℃.The ferroelectric orthorhombic phase(o-phase)in the as-deposited HZO films is detected by scanning transmission electron microscopy(STEM).This low fabrication temperature further extends the compatibility of ferroelectric HZO films to flexible electronics and avoids the cost imposed by following high-temperature annealing treatments.

Enhancing long-term stability of bio-photoelectrochemical cell by defect engineering of a WO_(3-x) photoanode

Bio-photoelectrochemical cells(BPECs)can further expand the use of conventional biofuel cells for renewable energy,but the poor stability of the photoelectrode still hinders their practical application.Herein,a BPEC capable of long-term operating in a fuel-free model is fabricated by WO3-xphotoanode with oxygen vacancy(Ov)and bilirubin oxidase catalyzed biocathode.The construction of Ov on the WO3surface significantly suppresses the dissolution of W species into the electrolyte,and improves the charge separation efficiency and the reaction kinetics during the photoelectrochemical oxygen evolution process,thus enhancing the stability and power output performance of the BPEC.As a result,the assembled BPEC can output an open circuit voltage of 0.81 V and deliver a maximum output power of up to 283μW cm^(-2).Impressively,the BPECs maintain 97%of their original power after 36000 s of consecutive discharge under an enclosed environment.This fuel-free BPEC based on a robust WO3-xphotoanode shows excellent promise for accurate application.

Ultrathin and Air-Stable Lithium Metal Anodes with Superlong Cycling Life in Ether/Ester-Based Electrolytes

Ultrathin and air-stable Li metal anodes hold great promise toward high-energy and high-safety Li metal batteries(LMBs).However,the application of LMBs is technically impeded by existing Li metal anodes with large thickness,high reactivity,and poor performance.Here,we developed a novel and scalable approach for the construction of a 10-μm-thick flexible and air-stable Li metal anode by conformally encapsulating Li within a multifunctional VN film.Specifically,the highly lithiophilic VN layer guides a uniform deposition of Li,while abundant and multilevel pores arising from assembly of ultrathin nanosheets enable a spatially confined immersion of metallic Li,thus ensuring an ultrathin and sandwiched Li anode.More impressively,the strong hydrophobicity of VN surface can effectively improve the stability of anode to humid air,whereas the highly conductive framework greatly boosts charge transfer dynamics and enhances Li utilization and high-rate capability.Benefiting from such fascinating features,the constructed Li-VN anode exhibits ultrastable cycling stability in both ether(2500 h)and carbonate(900 h)electrolytes,respectively.Moreover,even exposed to ambient air for 12 h,the anode still can retain~78%capacity,demonstrating excellent air-defendable capability.This work affords a promising strategy for fabricating high-performance,high-safety,and low-cost LMBs.

Some Characteristics and Innovative Development Countermeasures of Short Weather Video:A Case Study of the First Award-winning Excellent Short Weather Video in Hubei Province

With the advent of the era of short video,people can receive more information easy to be read and understood in a short time.Meteorological communicators should seize this opportunity,dig out characteristics and make innovations.In this paper,the first award-winning excellent short weather video in Hubei Province is taken as an example,to analyze some characteristics of short weather video,and some innovative development strategies are proposed.

Lithiophilic N-doped carbon bowls induced Li deposition in layered graphene film for advanced lithium metal batteries

Lithium(Li)metal with high theoretical capacity and low electrochemical potential is the most ideal anode for next-generation high-energy batteries.However,the practical implementation of Li anode has been hindered by dendritic growth and volume expansion during cycling,which results in low Coulombic efficiency(CE),short lifespan,and safety hazards.Here,we report a highly stable and dendrite-free Li metal anode by utilizing N-doped hollow porous bowl-like hard carbon/reduced graphene nanosheets(CB@rGO)hybrids as three-dimensional(3D)conductive and lithiophilic scaffold host.The lithiophilic carbon bowl(CB)mainly works as excellent guides during the Li plating process,whereas the rGO layer with high conductivity and mechanical stability maintains the integrity of the composite by confining the volume change in long-range order during cycling.Moreover,the local current density can be reduced due to the 3D conductive framework.Therefore,CB@rGO presents a low lithium metal nucleation overpotential of 18 mV,high CE of 98%,and stable cycling without obvious voltage fluctuation for over 600 cycles at a current density of 1 mA cm^(-2).Our study not only provides a good CB@rGO host and pre-Lithiated CB@rGO composite anode electrode,but also brings a new strategy of designing 3D electrodes for those active materials suffering from severe volume expansion.

耐瑞特:一种基于群体学习方法的新型硝酸盐制剂,可发挥更好的机体保护作用

硝酸盐是一种机体不可或缺的营养物质,已应用于多种疾病的预防和治疗研究.但由于半衰期短,硝酸盐的临床应用受限.为了提高硝酸盐可用性,突破传统的依赖大规模高通量生物实验的药物配伍研发瓶颈,本文报道了一种基于群体学习方法的药物配伍预测系统,该系统预测维生素C为与硝酸盐配伍的首选药物.通过采用微囊化技术,筛选并优化缓释制剂工艺,以维生素C、硝酸钠及壳聚糖3000为芯材,果胶与羧甲基纤维素钠为壁材制备硝酸盐纳米颗粒,命名为耐瑞特(Nanonitrator).耐瑞特的更长循环期显著提高了硝酸盐对放射性唾液腺损伤的疗效,同时维持了安全性.相同剂量的耐瑞特比硝酸盐(包含或不包含维生素C)可显著增强PI3K-Akt信号通路转导,更好地维持细胞内稳态,提示了其广泛的临床应用潜力.此外,本文还提供了一种将无机化合物加入缓释纳米颗粒的新方法.

Risk factors and molecular epidemiology of canine rabies in Beijing

Rabies is a serious public health problem in Asia and Africa.Approximately 99%of cases result from a bite by an infected dog.The high rabies risk countries are generally characterized by rapid urbanization;however,the prevalence and risk factors for rabies in urban dogs in developing countries remain unclear.Beijing,the capital of China,has been undergoing rapid urbanization,and implemented compulsory rabies immunization for dogs on October 1,2014.We evaluated the effects of this immunization policy and investigated the dynamics and determinants of the spread of dog rabies virus(RABV)in Beijing.Between 2013 and 2018,the positive rate of rabies in biting dogs declined significantly;79.6%of these were stray dogs.Reconstructed spatiotemporal diffusion for RABV presents a more central distribution within Beijing and a surrounding dissemination of virus lineage toward suburban areas,indicating that rabies is self-sustaining in Beijing.Continuous RABV phylogeographic reconstructions and logistic regression analysis of rabies cases revealed that rabies tended to remain in commercial areas,high-rise residences,demolition areas,and high-GDP,high-population and high-accessibility areas.Demolition areas,where many residents have abandoned their pets,are recognized as high-risk areas for rabies.Our findings reveal that the implementation of the immunization policy in Beijing has been effective in prevention and control of canine rabies,and because the prevalence of canine rabies results from multiple factors,emphasize the important role of multi-sectoral cooperation in rabies prevention and control.