The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the ...The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the long-cycling stability of batteries needs to be improved.Herein,the Mn-based Li-rich cathode materials with small amounts of Li2 MnO3 crystal domains and gradient doping of Al and Ti elements from the surface to the bulk have been developed to improve the structure and interface stability.Then the batteries with a high energy density of 600 Wh kg^(-1),excellent capacity retention of 99.7%with low voltage decay of 0.03 mV cycle^(-1) after 800 cycles,and good rates performances can be achieved.Therefore,the structure and cycling stability of low voltage Mn-based Li-rich cathode materials can be significantly improved by the bulk structure design and interface regulation,and this work has paved the way for developing low-cost and high-energy Mn-based energy storage batteries with long lifetime.展开更多
Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2) production can reduce the carbon footprint associated with transportation of water,waste,and energy carrier.This study...Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2) production can reduce the carbon footprint associated with transportation of water,waste,and energy carrier.This study reports Ir-doped NiFe_(2)O_(4)(NFI,~5 at%Ir)spinel layer with TiO_(2) overlayer(NFI/TiO_(2)),as a scalable heterojunction anode for direct electrolysis of wastewater with circumneutral pH in a single-compartment cell.In dilute(0.1 M)NaCl solutions,the NFI/TiO_(2) marks superior activity and selectivity for chlorine evolution reaction,outperforming the benchmark IrO_(2).Robust operation in near-neutral pH was confirmed.Electroanalyses including operando X-ray absorption spectroscopy unveiled crucial roles of TiO_(2) which serves both as the primary site for Cl−chemisorption and a protective layer for NFI as an ohmic contact.Galvanostatic electrolysis of NH4+-laden synthetic wastewater demonstrated that NFI/TiO_(2)not only achieves quasi-stoichiometric NH_(4)^(+)-to-N_(2)conversion,but also enhances H_(2)generation efficiency with minimal competing reactions such as reduction of dissolved oxygen and reactive chlorine.The scaled-up WEC with NFI/TiO_(2)was demonstrated for electrolysis of toilet wastewater.展开更多
Diel investigations of water environments are one means to holistically understand the dynamics and functional roles of phytoplankton,bacteria and viruses in these ecosystems.They have the potential to substantially i...Diel investigations of water environments are one means to holistically understand the dynamics and functional roles of phytoplankton,bacteria and viruses in these ecosystems.They have the potential to substantially impact carbon(C),nitrogen(N)and phosphorus(P)biogeochemistry through their respective roles.This study characterizes the phytoplankton,bacteria and virus communities and the elemental composition of various C,N and P nutrients flow over three diel cycles in tropical urban lake.Our results show that ratios of C:N:P fluctuated strongly from the lack of dissolved organic phosphorus(DOP)and PO_(4).Specifically,green algae peaked during day time and exudate dissolved organic matter(DOM)that strongly modulate dissolved organic carbon(DOC):DOP ratio to diel DOP limitation.Multiple linear regression and Stella modelling emphasize the roles of viruses together with Synechococcus as important nutrient recyclers of NH_(4)and PO_(4)in nutrients-limited waters.Respective normalised surface PO_(4)and combined surface and bottom NH_(4)concentration selected both viruses and Synechococcus as important drivers.Process model of N and P biogeochemical cycles can achieve 69%and 57%similar to observed concentration of NH_(4)and PO_(4),respectively.A short latent period of 9 hr was calculated,in addition to the calibrated high infectivity of viruses to Synechococcus.Taken together,the rapid turn-over between Synechococcus and viruses has biogeochemical significance,where the rapid recycling of essential nutrients allows for shortcuts in the N and P cycle,supporting a wide range of microbes.展开更多
Military missions in hostile environments are often costly and unpredictable,with squadrons sometimes facing isolation and resource scarcity.In such scenarios,critical components in vehicles,drones,and energy generato...Military missions in hostile environments are often costly and unpredictable,with squadrons sometimes facing isolation and resource scarcity.In such scenarios,critical components in vehicles,drones,and energy generators may require structural reinforcement or repair due to damage.This paper proposes a portable,on-site production method for molds under challenging conditions,where material supply is limited.The method utilizes large format additive manufacturing(LFAM)with recycled composite materials,sourced from end-of-life components and waste,as feedstock.The study investigates the microstructural effects of recycling through shredding techniques,using microscopic imaging.Three potential defense-sector applications are explored,specifically in the aerospace,automotive,and energy industries.Additionally,the influence of key printing parameters,particularly nonparallel plane deposition at a 45-degree angle,on the mechanical behavior of ABS reinforced with 20%glass fiber(GF)is examined.The results demonstrate the feasibility of this manufacturing approach,highlighting reductions in waste material and production times compared to traditional methods.Shorter layer times were found to reduce thermal gradients between layers,thereby improving layer adhesion.While 45-degree deposition enhanced Young's modulus,it slightly reduced interlayer adhesion quality.Furthermore,recycling-induced fiber length reduction led to material degradation,aligning with findings from previous studies.Challenges encountered during implementation included weak part adherence to the print bed and local excess material deposition.Overall,the proposed methodology offers a cost-effective alternative to traditional CNC machining for mold production,demonstrating its potential for on-demand manufacturing in resource-constrained environments.展开更多
With the advancement of electronic countermeasures,airborne synthetic aperture radar(SAR)systems are facing increasing challenges in maintaining effective performance in hostile environments.In particular,high-power i...With the advancement of electronic countermeasures,airborne synthetic aperture radar(SAR)systems are facing increasing challenges in maintaining effective performance in hostile environments.In particular,high-power interference can severely degrade SAR imaging and signal processing,often rendering target detection impossible.This highlights the urgent need for robust anti-interference solutions in both the signal processing and image processing domains.While current methods address interference across various domains,techniques such as waveform modification and spatial filtering typically increase the system costs and complexity.To overcome these limitations,we propose a novel approach that leverages the multi-domain characteristics of interference to efficiently suppress narrowband interference and repeater modulation interference.Specifically,narrowband interference is mitigated using notch filtering,a signal processing technique that effectively filters out unwanted frequencies,while repeater modulation interference is addressed through strong signal amplitude normalization,which enhances both the signal and image processing quality.These methods were validated through tests on real SAR data,demonstrating significant improvements in the imaging performance and system robustness.Our approach offers valuable insights for advancing anti-interference technologies in SAR systems and provides a cost-effective solution to enhance their resilience in complex electronic warfare environments.展开更多
Joint health is critical for musculoskeletal(MSK)conditions that are affecting approximately one-third of the global population.Monitoring of joint torque can offer an important pathway for the evaluation of joint hea...Joint health is critical for musculoskeletal(MSK)conditions that are affecting approximately one-third of the global population.Monitoring of joint torque can offer an important pathway for the evaluation of joint health and guided intervention.However,there is no technology that can provide the precision,effectiveness,low-resource setting,and longterm wearability to simultaneously achieve both rapid and accurate joint torque measurement to enable risk assessment of joint injury and long-term monitoring of joint rehabilitation in wider environments.Herein,we propose a piezoelectric boron nitride nanotubes(BNNTs)-based,AI-enabled wearable device for regular monitoring of joint torque.We first adopted an iterative inverse design to fabricate the wearable materials with a Poisson's ratio precisely matched to knee biomechanics.A highly sensitive piezoelectric film was constructed based on BNNTs and polydimethylsiloxane and applied to precisely capture the knee motion,while concurrently realizing self-sufficient energy harvesting.With the help of a lightweight on-device artificial neural network,the proposed wearable device was capable of accurately extracting targeted signals from the complex piezoelectric outputs and then effectively mapping these signals to their corresponding physical characteristics,including torque,angle,and loading.A real-time platform was constructed to demonstrate the capability of fine real-time torque estimation.This work offers a relatively low-cost wearable solution for effective,regular joint torque monitoring that can be made accessible to diverse populations in countries and regions with heterogeneous development levels,potentially producing wide-reaching global implications for joint health,MSK conditions,ageing,rehabilitation,personal health,and beyond.展开更多
The increasing population and continuous urbanization make food security a key consideration in sustainable development.Efficient farming strategies with low environmental footprints are thus increasingly required to ...The increasing population and continuous urbanization make food security a key consideration in sustainable development.Efficient farming strategies with low environmental footprints are thus increasingly required to meet food demands.This study presents a design for environmentally friendly,economical,and modular vertical farming systems,in which vegetables are cultivated in a carbon dioxide(CO_(2))-enriched atmosphere enabled by direct air capture(DAC)and subjected to artificial light exposure.We established a vertical farming setup and conducted experiments to identify productive cultivation strategies by regulating lighting,CO_(2)concentration,biochar application,and plant species.Additionally,a self-developed DAC rotary adsorber was utilized to achieve stable and efficient CO_(2)enrichment.Compared with the control group,the fresh weight of the vegetables in the experimental groups increased by up to 57.5%.Furthermore,we performed a comprehensive evaluation of the design and demonstrated that integrating photovoltaic-thermal(PVT)and DAC units increased the system’s net present value(NPV)by 157%compared with a conventional design without these units.Importantly,we found it possible to maintain the low carbon footprint of the system(0.468 kg-CO_(2)equivalent·kg−1(CO_(2)eq·kg−1)-vegetable)in the production process.Parametric studies and an application analysis on a global scale reveal the wide adaptability of this strategy to diverse conditions.These findings,together with the modular characteristics of vertical farming systems,highlight the promising potential of this design to increase food security and foster sustainable agriculture.展开更多
Proton exchange membranes(PEMs)are widely employed in energy conversion and storage devices including fuel cells(FCs),redox flow batteries(RFBs)and PEM water electrolysis(PEMWE).As one of the main components of these ...Proton exchange membranes(PEMs)are widely employed in energy conversion and storage devices including fuel cells(FCs),redox flow batteries(RFBs)and PEM water electrolysis(PEMWE).As one of the main components of these devices,a high-performance PEM is always desirable considering the cost challenges from both energy utilization efficiency and production cost.From this century,governments of countries worldwide have introduced PFAS(per-and polyfluoroalkyl substances)restriction related policies,which facilitate the extensive research on non-fluorinated PEMs.Besides,non-fluorinated PEMs become hot topics of all kinds of PEMs due to the advantages including excellent conductivity,high mechanical property,reduced swelling,low cost and reduced ion permeation of electrochemically active species.In this review,various types of non-fluorinated PEMs including main-chain-type hydrocarbon membranes,microphase separation membranes and membranes with rigid-twisted structure are comprehensively summarized.The basic properties of different types of non-fluorinated PEMs including water uptake,swelling ratio,oxidative stability,tensile strength and conductivity are compared and the corresponding application performance in FCs,RFBs and PEMWE are discussed.The state-of-the-art of the structural design in both monomers and polymers is reviewed for the construction of fast ion transport channels and high resistance of free radical attacks.Also,future challenges and possibilities for the development of non-fluorinated PEMs are comprehensively forecasted.展开更多
碳排放交易市场的建立,是一个基于经济学理论来解决气候变暖问题的具有价值的途径,其目的是发展低碳经济。在欧盟排放交易体系一级市场上,以欧盟排放配额(European Union Allowances,EUA)作为主要交易标的物的碳排放权交易市场已经成为...碳排放交易市场的建立,是一个基于经济学理论来解决气候变暖问题的具有价值的途径,其目的是发展低碳经济。在欧盟排放交易体系一级市场上,以欧盟排放配额(European Union Allowances,EUA)作为主要交易标的物的碳排放权交易市场已经成为一个重要的新兴贸易市场。随着碳排放权交易市场的不断发展,该市场的资本化程度逐渐深化,其金融属性也日益显著,并逐步融入到国际资本市场体系之中。与其它资本市场相类似,碳排放权交易市场之间也存在着复杂的非线性相关关系,而Copula函数可以用来捕捉这种相依结构特征。因此,文章选取欧盟排放配额(EUA)期货的日价格时间序列数据,首先假设新息序列服从学生t分布,运用ARMA-GARCH模型对经调整的对数收益率序列进行过滤,采用极大似然方法估计模型的参数,并得到残差序列,同时将其标准化而得到标准化残差;然后,将Kendall’s tau秩相关系数作为权重,采用最大生成树算法(maximum spanning tree algorithm)的序贯Copula选择方法构建合适的规则藤Copula模型,并运用基于序贯的极大似然方法估计规则藤Copula模型,以描述碳排放权交易市场之间复杂的相依结构特征。研究结果发现:在无条件下,t-copula函数可以较好地捕捉碳排放权市场之间的相依关系,说明市场存在明显的对称尾部;在Dec10EUA、Dec12EUA、Dec13EUA市场相依结构固定下,Dec11EUA与Dec14EUA市场之间的相依结构可以采用Gaussian copula函数来描述,而在Dec10EUA、Dec13EUA市场相依结构确定不变情形下,Dec12EUA与Dec14EUA市场之间的相依结构则适合采用Frank copula函数来捕捉,说明这些市场之间并没有出现尾部特征。进一步地,文章分别选择White信息矩阵等式拟合优度检验和基于概率积分转换(probability integral transform,PIT)与经验Copula过程(empirical copula process,ECP)混合方法的拟合优度检验,并基于Bootstrap方法,以Cramer von Mises(Cv M)检验统计量作为度量测度,来对模型进行拟合优度的检验。研究发现,构建的规则藤Copula模型能够较好地捕捉碳排放权市场之间的相依结构。这一研究结果,为准确探讨碳排放权交易市场之间、碳排放权交易市场与其它资本市场之间套期保值策略提供了一定的参考意义,也有利于提高碳排放权市场产品定价的准确度。展开更多
As urbanization process has been and will be happening in an unprecedented scale worldwide,strong requirements from academic research and practical fields for smart management and intelligent planning of cities are pr...As urbanization process has been and will be happening in an unprecedented scale worldwide,strong requirements from academic research and practical fields for smart management and intelligent planning of cities are pressing to handle increasing demands of infrastructure and potential risks of inhabitants’agglomeration in disaster management.Geospatial data and geographic information systems(GISs)are essential components for building smart cities in a basic way that maps the physical world into virtual environment as a referencing framework.On higher level,GIS has been becoming very important in smart cities on different sectors.In the digital city era,digital maps and geospatial databases have long been integrated in workflows in land management,urban planning and transportation in government.People have anticipated GIS to be more powerful not only as an archival and data management tool but also as spatial models for supporting decision-making in intelligent cities.Successful applications have been developed in private and public organizations by using GIS as a platform for data integration,a system for geospatial analysis and collection of models for visualization and decision-making.Location-based services on smart mobile devices in ubiquitous telecommunication networks are now an indispensable function that expands knowledge of the nature and connections among people.On data side,crowd-sourcing,real-time urban sensing and true 3-dimensional(3D)models and visualization have provided more advantages of GIS to final users and at the same time challenged current available solutions and technologies of data handling,visualization and human–computer interaction.On the technological side,Web 2.0 participatory applications provide the framework and environment for GIS to closer link to photogrammetry and computer vision,which empowers smart devices more capabilities.How to manage big geo-tagged data volumes collected by numerous sensors and implement professional GIS functions in a cloud computing environment are urgent questions to facilitate smart cities management.This paper reviews advancements of GIS in the management of cities as information systems to facilitate urban modelling and decision-making,as referencing basis to integrate social network media,and concludes that an interdisciplinary urban GIS is needed to support development of smart cities.We take Singapore as a case of GIS pervasive applications,which has strategically made a master plan of national information infrastructure and has been implementing geospatial collaboration environments for public and private sectors.展开更多
Developing a flexible,light-weight and effective electromagnetic(EM)absorber remains challenging despite being on increasing demand as more wearable devices and portable electronics are commercialized.Herein,we report...Developing a flexible,light-weight and effective electromagnetic(EM)absorber remains challenging despite being on increasing demand as more wearable devices and portable electronics are commercialized.Herein,we report a flexible and lightweight hybrid paper by a facile vacuumfiltration-induced self-assembly process,in which cotton-derived carbon fibers serve as flexible skeletons,compactly surrounded by other microwave-attenuating components(reduced graphene oxide and Fe3O4@C nanowires).Owing to its unique architecture and synergy of the three components,the asprepared hybrid paper exhibits flexible and lightweight features as well as superb microwave absorption performance.Maximum absorption intensity with reflection loss as low as-63 dB can be achieved,and its broadest frequency absorption bandwidth of 5.8 GHz almost covers the entire Ku band.Such a hybrid paper is promising to cope with ever-increasing EM interference.The work also paves the way to develop low-cost and flexible EM wave absorber from biomass through a facile method.展开更多
Electrochemical water splitting consists of two elementary reactions i.e.,hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Developing robust HER and OER technologies necessitates a molecular picture ...Electrochemical water splitting consists of two elementary reactions i.e.,hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Developing robust HER and OER technologies necessitates a molecular picture of reaction mechanism,yet the reactants for water splitting reactions are unfortunately not fully understood.Here we utilize magnetic field to understand proton transport in HER,and hydroxide ion transport in OER,to discuss the possible implications on understanding the reactants for HER and OER.Magnetic field is a known tool for changing the movement of charged species like ions,e.g.the magnetic‐field‐improved Cu^(2+)transportation near the electrode in Cu electrodeposition.However,applying a magnetic field does not affect the HER or OER rate across various pH,which challenges the traditional opinion that charged species(i.e.proton and hydroxide ion)act as the reactant.This anomalous response of HER and OER to magnetic field,and the fact that the transport of proton and hydroxide ion follow Grotthuss mechanism,collectively indicate water may act as the universal reactant for HER and OER across various pH.With the aid of magnetic field,this work serves as an understanding of water might be the reactant in HER and OER,and possibly in other electrocatalysis reactions involving protonation and deprotonation step.A model that simply focuses on the charged species but overlooking the complexity of the whole electrolyte phase where water is the dominant species,may not reasonably reflect the electrochemistry of HER and OER in aqueous electrolyte.展开更多
Sodium-ion capacitors(SICs)have received increasing interest for grid stationary energy storage application due to their affordability,high power,and energy densities.The major challenge for SICs is to overcome the ki...Sodium-ion capacitors(SICs)have received increasing interest for grid stationary energy storage application due to their affordability,high power,and energy densities.The major challenge for SICs is to overcome the kinetics imbalance between faradaic anode and nonfaradaic cathode.To boost the Na+reaction kinetics,the present work demonstrated a high-rate MnS-based anode by embedding the MnS nanocrystals into the N,S-co-doped carbon matrix(MnS@NSC).Benefiting from the fast pseudocapacitive Na+storage behavior,the resulting composite exhibits extraordinary rate capability(205.6 mAh g−1 at 10 A g−1)and outstanding cycling stability without notable degradation after 2000 cycles.A prototype SIC was demonstrated using MnS@NSC anode and N-doped porous carbon(NC)cathode;the obtained hybrid SIC device can display a high energy density of 139.8 Wh kg−1 and high power density of 11,500 W kg−1,as well as excellent cyclability with 84.5%capacitance retention after 3000 cycles.The superior electrochemical performance is contributed to downsizing of MnS and encapsulation of conductive N,S-co-doped carbon matrix,which not only promote the Na+and electrons transport,but also buffer the volume variations and maintain the structure integrity during Na+insertion/extraction,enabling its comparable fast reaction kinetics and cyclability with NC cathode.展开更多
The rapid construction of artificial reservoirs in metropolises has promoted the emergence of city-river-reservoir systems worldwide.This study investigated the environmental behaviors and risks of heavy metals in the...The rapid construction of artificial reservoirs in metropolises has promoted the emergence of city-river-reservoir systems worldwide.This study investigated the environmental behaviors and risks of heavy metals in the aquatic environment of a typical system composed of main watersheds in Suzhou and Jinze Reservoir in Shanghai.Results shown that Mn,Zn and Cu were the dominant metals detected in multiple phases.Cd,Mn and Zn were mainly presented in exchangeable fraction and exhibited high bioavailability.Great proportion and high mobility of metals were found in suspended particulate matter(SPM),suggesting that SPM can greatly affect metal multi-phase distribution process.Spatially,city system(Ci S)exhibited more serious metal pollution and higher ecological risk than river system(Ri S)and reservoir system(Re S)owing to the diverse emission sources.Ci S and Re S were regarded as critical pollution source and sink,respectively,while Ri S was a vital transportation aisle.Microbial community in sediments exhibited evident spatial variation and obviously modified by exchangeable metals and nutrients.In particular,Bacteroidetes and Firmicutes presented significant positive correlations with most exchangeable metals.Risk assessment implied that As,Sb and Ni in water may pose potential carcinogenic risk to human health.Nevertheless,Re S was in a fairly safe state.Hg was the main risk contributor in SPM,while Cu,Zn,Ni and Sb showed moderate risk in sediments.Overall,Hg,Sb and Ci S were screened out as priority metals and system,respectively.More attention should be paid to these priority issues to promote the sustainable development of the watershed.展开更多
Photocatalytic water splitting and carbon dioxide reduction provide us clean and sustainable energy resources. The carbon dioxide reduction is also the redemption of the greenhouse effect. MoS/TiOphotocatalysts based ...Photocatalytic water splitting and carbon dioxide reduction provide us clean and sustainable energy resources. The carbon dioxide reduction is also the redemption of the greenhouse effect. MoS/TiOphotocatalysts based on TiOnanoplates have been synthesized via a hydrothermal acidification route for water and carbon dioxide reduction reactions. This facile approach generates well dispersed Mo S3 with low crystallinity on the surface of TiOnanoplates. The as-synthesized MoS/TiOphotocatalyst showed considerable activity for both water reduction and carbon dioxide reduction. The thermal treatment effects of TiO, the loading percentage of MoSand the crystalline phase of TiOhave been investigated towards the photocatalytic performance. TiOnanoplate synthesized through hydrothermal reaction with the presence of HF acid is an ideal semiconductor material for the loading of MoSfor photocatalytic water and carbon dioxide reduction simultaneously in EDTA sacrificial solution.展开更多
Lithium-sulfur batteries(LSBs)are considered as the next generation of advanced rechargeable batteries because of their high energy density.In this study,sulfur and CoxS electrocatalyst are deposited on carbon nanotub...Lithium-sulfur batteries(LSBs)are considered as the next generation of advanced rechargeable batteries because of their high energy density.In this study,sulfur and CoxS electrocatalyst are deposited on carbon nanotube buckypaper(S/CoxS/BP)by a facile electrodeposition method and are used as a binder-free high-performance cathode for LSBs.Elemental sulfur is deposited on buckypaper by electrooxidation of a polysulfide solution(-S6^2-).This approach substantially increased the current and time efficiency of sulfur electrochemical deposition on conductive material for LSBs.S/CoxS/BP cathode could deliver an initial discharge capacity as high as 1650 mAh g^-1 at 0.1 C,which is close to the theoretical capacity of sulfur.At current rate of 0.5 C,the S/CoxS/BP has a capacity of 1420 mAh g^-1 at the first cycle and 715 mAh g^-1 after 500 cycles with a fading rate of 0.099%per cycle.The high capacity of S/CoxS/BP is attributed to both the homogeneous dispersion of nanosized sulfur within BP and the presence of CoxS catalyst.The sodium dodecyl sulfate(SDS)pretreatment of BP renders it polarity to bind polysulfides and thus facilitates the good dispersibility of nanosized sulfur within BP.CoxS catalyst accelerates the kinetics of polysulfide conversion and reduces the presence of polysulfide in the cathode,which suppresses the polysulfide diffusion to anode,i.e.,the shuttle effect.The mitigation of the active material loss improves not only the capacity but also the cyclability of S/CoxS/BP.展开更多
It is our goal to make today’s and future cities smart,sustainable and resilient.In order to achieve this,it is fundamental to understand how each city works,to formalize the knowledge gained and to apply it to a cit...It is our goal to make today’s and future cities smart,sustainable and resilient.In order to achieve this,it is fundamental to understand how each city works,to formalize the knowledge gained and to apply it to a city model as the base for simulations that can generate future scenarios with a high level of probability.The nature of this model,which must cover design,qualitative and quantitative aspects,has changed over time.In this study,we focus on the role of the spatial dimension and of geometry in a city model.Emerging from being a dominating generative force in ancient cities,spatial modeling has developed into an underlying description language for present and future cities to define functions and properties of the city in space and time.The example of the stocks and flows model applied to the city depicts where and how spatial modeling influences the design,construction and performance of the future Smart City.展开更多
基金supported by the National Key R&D Program of China(No.2022YFB2404400)the National Natural Science Foundation of China(Nos.U23A20577,52372168,92263206 and 21975006)+1 种基金the“The Youth Beijing Scholars program”(No.PXM2021_014204_000023)the Beijing Natural Science Foundation(Nos.2222001 and KM202110005009).
文摘The cobalt-free Mn-based Li-rich layered oxide material has the advantages of low cost,high energy density,and good performance at low temperatures,and is the promising choice for energy storage batteries.However,the long-cycling stability of batteries needs to be improved.Herein,the Mn-based Li-rich cathode materials with small amounts of Li2 MnO3 crystal domains and gradient doping of Al and Ti elements from the surface to the bulk have been developed to improve the structure and interface stability.Then the batteries with a high energy density of 600 Wh kg^(-1),excellent capacity retention of 99.7%with low voltage decay of 0.03 mV cycle^(-1) after 800 cycles,and good rates performances can be achieved.Therefore,the structure and cycling stability of low voltage Mn-based Li-rich cathode materials can be significantly improved by the bulk structure design and interface regulation,and this work has paved the way for developing low-cost and high-energy Mn-based energy storage batteries with long lifetime.
基金supported by the National Research Foundation of Korea(NRF)grants(2022R1A2C4001228,2022M3H4A4097524,2022M3I3A1082499,and 2021M3I3A1084818)the Technology Innovation Program(20026415)of the Ministry of Trade,Industry&Energy(MOTIE,Korea)the supports from Nanopac for fabrication of scaled-up reactor.
文摘Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2) production can reduce the carbon footprint associated with transportation of water,waste,and energy carrier.This study reports Ir-doped NiFe_(2)O_(4)(NFI,~5 at%Ir)spinel layer with TiO_(2) overlayer(NFI/TiO_(2)),as a scalable heterojunction anode for direct electrolysis of wastewater with circumneutral pH in a single-compartment cell.In dilute(0.1 M)NaCl solutions,the NFI/TiO_(2) marks superior activity and selectivity for chlorine evolution reaction,outperforming the benchmark IrO_(2).Robust operation in near-neutral pH was confirmed.Electroanalyses including operando X-ray absorption spectroscopy unveiled crucial roles of TiO_(2) which serves both as the primary site for Cl−chemisorption and a protective layer for NFI as an ohmic contact.Galvanostatic electrolysis of NH4+-laden synthetic wastewater demonstrated that NFI/TiO_(2)not only achieves quasi-stoichiometric NH_(4)^(+)-to-N_(2)conversion,but also enhances H_(2)generation efficiency with minimal competing reactions such as reduction of dissolved oxygen and reactive chlorine.The scaled-up WEC with NFI/TiO_(2)was demonstrated for electrolysis of toilet wastewater.
文摘Diel investigations of water environments are one means to holistically understand the dynamics and functional roles of phytoplankton,bacteria and viruses in these ecosystems.They have the potential to substantially impact carbon(C),nitrogen(N)and phosphorus(P)biogeochemistry through their respective roles.This study characterizes the phytoplankton,bacteria and virus communities and the elemental composition of various C,N and P nutrients flow over three diel cycles in tropical urban lake.Our results show that ratios of C:N:P fluctuated strongly from the lack of dissolved organic phosphorus(DOP)and PO_(4).Specifically,green algae peaked during day time and exudate dissolved organic matter(DOM)that strongly modulate dissolved organic carbon(DOC):DOP ratio to diel DOP limitation.Multiple linear regression and Stella modelling emphasize the roles of viruses together with Synechococcus as important nutrient recyclers of NH_(4)and PO_(4)in nutrients-limited waters.Respective normalised surface PO_(4)and combined surface and bottom NH_(4)concentration selected both viruses and Synechococcus as important drivers.Process model of N and P biogeochemical cycles can achieve 69%and 57%similar to observed concentration of NH_(4)and PO_(4),respectively.A short latent period of 9 hr was calculated,in addition to the calibrated high infectivity of viruses to Synechococcus.Taken together,the rapid turn-over between Synechococcus and viruses has biogeochemical significance,where the rapid recycling of essential nutrients allows for shortcuts in the N and P cycle,supporting a wide range of microbes.
基金Generalitat Valenciana(GVA)and Spanish Ministry of Science and Innovation(Grant Nos.TED2021-130879 B-C21,CIACIF/2021/286,PID2023-151110OB-I00,and CIPROM/2022/3)to provide funds for conducting experiments and software licensessupported by the National Research Foundation,Prime Minister's Office,Singapore under its Campus for Research Excellence and Technological Enterprise(CREATE)programme。
文摘Military missions in hostile environments are often costly and unpredictable,with squadrons sometimes facing isolation and resource scarcity.In such scenarios,critical components in vehicles,drones,and energy generators may require structural reinforcement or repair due to damage.This paper proposes a portable,on-site production method for molds under challenging conditions,where material supply is limited.The method utilizes large format additive manufacturing(LFAM)with recycled composite materials,sourced from end-of-life components and waste,as feedstock.The study investigates the microstructural effects of recycling through shredding techniques,using microscopic imaging.Three potential defense-sector applications are explored,specifically in the aerospace,automotive,and energy industries.Additionally,the influence of key printing parameters,particularly nonparallel plane deposition at a 45-degree angle,on the mechanical behavior of ABS reinforced with 20%glass fiber(GF)is examined.The results demonstrate the feasibility of this manufacturing approach,highlighting reductions in waste material and production times compared to traditional methods.Shorter layer times were found to reduce thermal gradients between layers,thereby improving layer adhesion.While 45-degree deposition enhanced Young's modulus,it slightly reduced interlayer adhesion quality.Furthermore,recycling-induced fiber length reduction led to material degradation,aligning with findings from previous studies.Challenges encountered during implementation included weak part adherence to the print bed and local excess material deposition.Overall,the proposed methodology offers a cost-effective alternative to traditional CNC machining for mold production,demonstrating its potential for on-demand manufacturing in resource-constrained environments.
文摘With the advancement of electronic countermeasures,airborne synthetic aperture radar(SAR)systems are facing increasing challenges in maintaining effective performance in hostile environments.In particular,high-power interference can severely degrade SAR imaging and signal processing,often rendering target detection impossible.This highlights the urgent need for robust anti-interference solutions in both the signal processing and image processing domains.While current methods address interference across various domains,techniques such as waveform modification and spatial filtering typically increase the system costs and complexity.To overcome these limitations,we propose a novel approach that leverages the multi-domain characteristics of interference to efficiently suppress narrowband interference and repeater modulation interference.Specifically,narrowband interference is mitigated using notch filtering,a signal processing technique that effectively filters out unwanted frequencies,while repeater modulation interference is addressed through strong signal amplitude normalization,which enhances both the signal and image processing quality.These methods were validated through tests on real SAR data,demonstrating significant improvements in the imaging performance and system robustness.Our approach offers valuable insights for advancing anti-interference technologies in SAR systems and provides a cost-effective solution to enhance their resilience in complex electronic warfare environments.
基金support from the EPSRC REMIN project(EP/W009412/1)the UCL Fellowship Incubator Award+6 种基金the EPSRC award(TEGMOF EP/Z534146/1)for fundingfinancial support from the China Scholarship Councilfinancial support from UCL Research Excellence Scholarshipthe Wellcome Trust and EPSRC through the WEISS Centre(grant:203145Z/16/Z)at UCLsupport from the Royal Society Research Grant(RGSR2222333)Engineering and Physical Sciences Research Council Grant(13171178 R00287)European Innovative Council(EIC)under the European Union’s Horizon Europe research and innovation program(Grant agreement No.101099093)。
文摘Joint health is critical for musculoskeletal(MSK)conditions that are affecting approximately one-third of the global population.Monitoring of joint torque can offer an important pathway for the evaluation of joint health and guided intervention.However,there is no technology that can provide the precision,effectiveness,low-resource setting,and longterm wearability to simultaneously achieve both rapid and accurate joint torque measurement to enable risk assessment of joint injury and long-term monitoring of joint rehabilitation in wider environments.Herein,we propose a piezoelectric boron nitride nanotubes(BNNTs)-based,AI-enabled wearable device for regular monitoring of joint torque.We first adopted an iterative inverse design to fabricate the wearable materials with a Poisson's ratio precisely matched to knee biomechanics.A highly sensitive piezoelectric film was constructed based on BNNTs and polydimethylsiloxane and applied to precisely capture the knee motion,while concurrently realizing self-sufficient energy harvesting.With the help of a lightweight on-device artificial neural network,the proposed wearable device was capable of accurately extracting targeted signals from the complex piezoelectric outputs and then effectively mapping these signals to their corresponding physical characteristics,including torque,angle,and loading.A real-time platform was constructed to demonstrate the capability of fine real-time torque estimation.This work offers a relatively low-cost wearable solution for effective,regular joint torque monitoring that can be made accessible to diverse populations in countries and regions with heterogeneous development levels,potentially producing wide-reaching global implications for joint health,MSK conditions,ageing,rehabilitation,personal health,and beyond.
基金the National Research Foundation(NRF),Prime Minister’s Office,Singapore,under its Campus for Research Excellence and Technological Enterprise(CREATE)program(A-0001032-01-00)the National Natural Science Foundation of China(52376011).
文摘The increasing population and continuous urbanization make food security a key consideration in sustainable development.Efficient farming strategies with low environmental footprints are thus increasingly required to meet food demands.This study presents a design for environmentally friendly,economical,and modular vertical farming systems,in which vegetables are cultivated in a carbon dioxide(CO_(2))-enriched atmosphere enabled by direct air capture(DAC)and subjected to artificial light exposure.We established a vertical farming setup and conducted experiments to identify productive cultivation strategies by regulating lighting,CO_(2)concentration,biochar application,and plant species.Additionally,a self-developed DAC rotary adsorber was utilized to achieve stable and efficient CO_(2)enrichment.Compared with the control group,the fresh weight of the vegetables in the experimental groups increased by up to 57.5%.Furthermore,we performed a comprehensive evaluation of the design and demonstrated that integrating photovoltaic-thermal(PVT)and DAC units increased the system’s net present value(NPV)by 157%compared with a conventional design without these units.Importantly,we found it possible to maintain the low carbon footprint of the system(0.468 kg-CO_(2)equivalent·kg−1(CO_(2)eq·kg−1)-vegetable)in the production process.Parametric studies and an application analysis on a global scale reveal the wide adaptability of this strategy to diverse conditions.These findings,together with the modular characteristics of vertical farming systems,highlight the promising potential of this design to increase food security and foster sustainable agriculture.
基金funded by the National Key Research and Development Program of China(No.2022YFB3805300)National Natural Science Foundation of China(Grant No.22125801,22005010).
文摘Proton exchange membranes(PEMs)are widely employed in energy conversion and storage devices including fuel cells(FCs),redox flow batteries(RFBs)and PEM water electrolysis(PEMWE).As one of the main components of these devices,a high-performance PEM is always desirable considering the cost challenges from both energy utilization efficiency and production cost.From this century,governments of countries worldwide have introduced PFAS(per-and polyfluoroalkyl substances)restriction related policies,which facilitate the extensive research on non-fluorinated PEMs.Besides,non-fluorinated PEMs become hot topics of all kinds of PEMs due to the advantages including excellent conductivity,high mechanical property,reduced swelling,low cost and reduced ion permeation of electrochemically active species.In this review,various types of non-fluorinated PEMs including main-chain-type hydrocarbon membranes,microphase separation membranes and membranes with rigid-twisted structure are comprehensively summarized.The basic properties of different types of non-fluorinated PEMs including water uptake,swelling ratio,oxidative stability,tensile strength and conductivity are compared and the corresponding application performance in FCs,RFBs and PEMWE are discussed.The state-of-the-art of the structural design in both monomers and polymers is reviewed for the construction of fast ion transport channels and high resistance of free radical attacks.Also,future challenges and possibilities for the development of non-fluorinated PEMs are comprehensively forecasted.
文摘碳排放交易市场的建立,是一个基于经济学理论来解决气候变暖问题的具有价值的途径,其目的是发展低碳经济。在欧盟排放交易体系一级市场上,以欧盟排放配额(European Union Allowances,EUA)作为主要交易标的物的碳排放权交易市场已经成为一个重要的新兴贸易市场。随着碳排放权交易市场的不断发展,该市场的资本化程度逐渐深化,其金融属性也日益显著,并逐步融入到国际资本市场体系之中。与其它资本市场相类似,碳排放权交易市场之间也存在着复杂的非线性相关关系,而Copula函数可以用来捕捉这种相依结构特征。因此,文章选取欧盟排放配额(EUA)期货的日价格时间序列数据,首先假设新息序列服从学生t分布,运用ARMA-GARCH模型对经调整的对数收益率序列进行过滤,采用极大似然方法估计模型的参数,并得到残差序列,同时将其标准化而得到标准化残差;然后,将Kendall’s tau秩相关系数作为权重,采用最大生成树算法(maximum spanning tree algorithm)的序贯Copula选择方法构建合适的规则藤Copula模型,并运用基于序贯的极大似然方法估计规则藤Copula模型,以描述碳排放权交易市场之间复杂的相依结构特征。研究结果发现:在无条件下,t-copula函数可以较好地捕捉碳排放权市场之间的相依关系,说明市场存在明显的对称尾部;在Dec10EUA、Dec12EUA、Dec13EUA市场相依结构固定下,Dec11EUA与Dec14EUA市场之间的相依结构可以采用Gaussian copula函数来描述,而在Dec10EUA、Dec13EUA市场相依结构确定不变情形下,Dec12EUA与Dec14EUA市场之间的相依结构则适合采用Frank copula函数来捕捉,说明这些市场之间并没有出现尾部特征。进一步地,文章分别选择White信息矩阵等式拟合优度检验和基于概率积分转换(probability integral transform,PIT)与经验Copula过程(empirical copula process,ECP)混合方法的拟合优度检验,并基于Bootstrap方法,以Cramer von Mises(Cv M)检验统计量作为度量测度,来对模型进行拟合优度的检验。研究发现,构建的规则藤Copula模型能够较好地捕捉碳排放权市场之间的相依结构。这一研究结果,为准确探讨碳排放权交易市场之间、碳排放权交易市场与其它资本市场之间套期保值策略提供了一定的参考意义,也有利于提高碳排放权市场产品定价的准确度。
文摘As urbanization process has been and will be happening in an unprecedented scale worldwide,strong requirements from academic research and practical fields for smart management and intelligent planning of cities are pressing to handle increasing demands of infrastructure and potential risks of inhabitants’agglomeration in disaster management.Geospatial data and geographic information systems(GISs)are essential components for building smart cities in a basic way that maps the physical world into virtual environment as a referencing framework.On higher level,GIS has been becoming very important in smart cities on different sectors.In the digital city era,digital maps and geospatial databases have long been integrated in workflows in land management,urban planning and transportation in government.People have anticipated GIS to be more powerful not only as an archival and data management tool but also as spatial models for supporting decision-making in intelligent cities.Successful applications have been developed in private and public organizations by using GIS as a platform for data integration,a system for geospatial analysis and collection of models for visualization and decision-making.Location-based services on smart mobile devices in ubiquitous telecommunication networks are now an indispensable function that expands knowledge of the nature and connections among people.On data side,crowd-sourcing,real-time urban sensing and true 3-dimensional(3D)models and visualization have provided more advantages of GIS to final users and at the same time challenged current available solutions and technologies of data handling,visualization and human–computer interaction.On the technological side,Web 2.0 participatory applications provide the framework and environment for GIS to closer link to photogrammetry and computer vision,which empowers smart devices more capabilities.How to manage big geo-tagged data volumes collected by numerous sensors and implement professional GIS functions in a cloud computing environment are urgent questions to facilitate smart cities management.This paper reviews advancements of GIS in the management of cities as information systems to facilitate urban modelling and decision-making,as referencing basis to integrate social network media,and concludes that an interdisciplinary urban GIS is needed to support development of smart cities.We take Singapore as a case of GIS pervasive applications,which has strategically made a master plan of national information infrastructure and has been implementing geospatial collaboration environments for public and private sectors.
基金financial support from National Natural Science Foundation of China(No.:51971111)the National Research Foundation,Prime Minister’s Office,Singapore under its Campus for Research Excellence and Technological Enterprise(CREATE)program+2 种基金the Funding for Outstanding Doctoral Dissertation in NUAA(No.BCXJ17-07)Postgraduate Research&Practice Innovation of Jiangsu Province(KYCX17_0252)the Open Research Fund of Jiangsu Provincial Key Laboratory of Bionic Functional Materials。
文摘Developing a flexible,light-weight and effective electromagnetic(EM)absorber remains challenging despite being on increasing demand as more wearable devices and portable electronics are commercialized.Herein,we report a flexible and lightweight hybrid paper by a facile vacuumfiltration-induced self-assembly process,in which cotton-derived carbon fibers serve as flexible skeletons,compactly surrounded by other microwave-attenuating components(reduced graphene oxide and Fe3O4@C nanowires).Owing to its unique architecture and synergy of the three components,the asprepared hybrid paper exhibits flexible and lightweight features as well as superb microwave absorption performance.Maximum absorption intensity with reflection loss as low as-63 dB can be achieved,and its broadest frequency absorption bandwidth of 5.8 GHz almost covers the entire Ku band.Such a hybrid paper is promising to cope with ever-increasing EM interference.The work also paves the way to develop low-cost and flexible EM wave absorber from biomass through a facile method.
基金supported by the Singapore MOE Tier 2 MOE2018-T2-2-027the Singapore National Research Foundation under its Campus for Research Excellence and Technological Enterprise (CREATE) Programme
文摘Electrochemical water splitting consists of two elementary reactions i.e.,hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Developing robust HER and OER technologies necessitates a molecular picture of reaction mechanism,yet the reactants for water splitting reactions are unfortunately not fully understood.Here we utilize magnetic field to understand proton transport in HER,and hydroxide ion transport in OER,to discuss the possible implications on understanding the reactants for HER and OER.Magnetic field is a known tool for changing the movement of charged species like ions,e.g.the magnetic‐field‐improved Cu^(2+)transportation near the electrode in Cu electrodeposition.However,applying a magnetic field does not affect the HER or OER rate across various pH,which challenges the traditional opinion that charged species(i.e.proton and hydroxide ion)act as the reactant.This anomalous response of HER and OER to magnetic field,and the fact that the transport of proton and hydroxide ion follow Grotthuss mechanism,collectively indicate water may act as the universal reactant for HER and OER across various pH.With the aid of magnetic field,this work serves as an understanding of water might be the reactant in HER and OER,and possibly in other electrocatalysis reactions involving protonation and deprotonation step.A model that simply focuses on the charged species but overlooking the complexity of the whole electrolyte phase where water is the dominant species,may not reasonably reflect the electrochemistry of HER and OER in aqueous electrolyte.
基金financially supported by the NRF Investigatorship (NRFI), Award No. NRF-NRFI2016-05the Campus for Research Excellent and Technological Enterprise (CREATE),National Research Foundation, Prime Minister’s Office, Singapore
文摘Sodium-ion capacitors(SICs)have received increasing interest for grid stationary energy storage application due to their affordability,high power,and energy densities.The major challenge for SICs is to overcome the kinetics imbalance between faradaic anode and nonfaradaic cathode.To boost the Na+reaction kinetics,the present work demonstrated a high-rate MnS-based anode by embedding the MnS nanocrystals into the N,S-co-doped carbon matrix(MnS@NSC).Benefiting from the fast pseudocapacitive Na+storage behavior,the resulting composite exhibits extraordinary rate capability(205.6 mAh g−1 at 10 A g−1)and outstanding cycling stability without notable degradation after 2000 cycles.A prototype SIC was demonstrated using MnS@NSC anode and N-doped porous carbon(NC)cathode;the obtained hybrid SIC device can display a high energy density of 139.8 Wh kg−1 and high power density of 11,500 W kg−1,as well as excellent cyclability with 84.5%capacitance retention after 3000 cycles.The superior electrochemical performance is contributed to downsizing of MnS and encapsulation of conductive N,S-co-doped carbon matrix,which not only promote the Na+and electrons transport,but also buffer the volume variations and maintain the structure integrity during Na+insertion/extraction,enabling its comparable fast reaction kinetics and cyclability with NC cathode.
基金supported by the Scientific and Innovative Action Plan of Shanghai(CN)“One Belt One Road”International Cooperation Project(No.20260750400)the Singapore National Research Foundation(NRF)under its Campus for Research Excellence and Technological Enterprise(CREATE)program(E2S2-CREATE project ES-2:Detection,Assessment&Modelling of Emerging Contaminants in the Urban Environment)。
文摘The rapid construction of artificial reservoirs in metropolises has promoted the emergence of city-river-reservoir systems worldwide.This study investigated the environmental behaviors and risks of heavy metals in the aquatic environment of a typical system composed of main watersheds in Suzhou and Jinze Reservoir in Shanghai.Results shown that Mn,Zn and Cu were the dominant metals detected in multiple phases.Cd,Mn and Zn were mainly presented in exchangeable fraction and exhibited high bioavailability.Great proportion and high mobility of metals were found in suspended particulate matter(SPM),suggesting that SPM can greatly affect metal multi-phase distribution process.Spatially,city system(Ci S)exhibited more serious metal pollution and higher ecological risk than river system(Ri S)and reservoir system(Re S)owing to the diverse emission sources.Ci S and Re S were regarded as critical pollution source and sink,respectively,while Ri S was a vital transportation aisle.Microbial community in sediments exhibited evident spatial variation and obviously modified by exchangeable metals and nutrients.In particular,Bacteroidetes and Firmicutes presented significant positive correlations with most exchangeable metals.Risk assessment implied that As,Sb and Ni in water may pose potential carcinogenic risk to human health.Nevertheless,Re S was in a fairly safe state.Hg was the main risk contributor in SPM,while Cu,Zn,Ni and Sb showed moderate risk in sediments.Overall,Hg,Sb and Ci S were screened out as priority metals and system,respectively.More attention should be paid to these priority issues to promote the sustainable development of the watershed.
基金supported by the Fundamental Research Funds for the Central Universities of Chinathe Starting Research Funds of Shaanxi Normal University for Mainstay Young Scholars+2 种基金the National Environment Agency of Singapore under the Environment Technology Research Programme(ETRP)through Project No.ETRP 1002 103Singapore National Research Foundation(NRF)through the Singapore-Berkeley Research Initiative for Sustainable Energy(SinBeRISE)Cambridge Centre for Carbon Reduction in Chemical Technology(C4T)CREATE Programmes
文摘Photocatalytic water splitting and carbon dioxide reduction provide us clean and sustainable energy resources. The carbon dioxide reduction is also the redemption of the greenhouse effect. MoS/TiOphotocatalysts based on TiOnanoplates have been synthesized via a hydrothermal acidification route for water and carbon dioxide reduction reactions. This facile approach generates well dispersed Mo S3 with low crystallinity on the surface of TiOnanoplates. The as-synthesized MoS/TiOphotocatalyst showed considerable activity for both water reduction and carbon dioxide reduction. The thermal treatment effects of TiO, the loading percentage of MoSand the crystalline phase of TiOhave been investigated towards the photocatalytic performance. TiOnanoplate synthesized through hydrothermal reaction with the presence of HF acid is an ideal semiconductor material for the loading of MoSfor photocatalytic water and carbon dioxide reduction simultaneously in EDTA sacrificial solution.
基金conducted by Nanomaterials for Energy and Energy-Water Nexus(NEW)Programme under Singapore-HUJ Alliance for Research and Enterprise(SHARE)in the Campus for Research Excellence and Technological Enterprise(CREATE)that is supported by the National Research Foundation,Prime Minister’s O ce,Singaporesupported also by the Israel National Research Center for Electrochemical Propulsion(INREP)。
文摘Lithium-sulfur batteries(LSBs)are considered as the next generation of advanced rechargeable batteries because of their high energy density.In this study,sulfur and CoxS electrocatalyst are deposited on carbon nanotube buckypaper(S/CoxS/BP)by a facile electrodeposition method and are used as a binder-free high-performance cathode for LSBs.Elemental sulfur is deposited on buckypaper by electrooxidation of a polysulfide solution(-S6^2-).This approach substantially increased the current and time efficiency of sulfur electrochemical deposition on conductive material for LSBs.S/CoxS/BP cathode could deliver an initial discharge capacity as high as 1650 mAh g^-1 at 0.1 C,which is close to the theoretical capacity of sulfur.At current rate of 0.5 C,the S/CoxS/BP has a capacity of 1420 mAh g^-1 at the first cycle and 715 mAh g^-1 after 500 cycles with a fading rate of 0.099%per cycle.The high capacity of S/CoxS/BP is attributed to both the homogeneous dispersion of nanosized sulfur within BP and the presence of CoxS catalyst.The sodium dodecyl sulfate(SDS)pretreatment of BP renders it polarity to bind polysulfides and thus facilitates the good dispersibility of nanosized sulfur within BP.CoxS catalyst accelerates the kinetics of polysulfide conversion and reduces the presence of polysulfide in the cathode,which suppresses the polysulfide diffusion to anode,i.e.,the shuttle effect.The mitigation of the active material loss improves not only the capacity but also the cyclability of S/CoxS/BP.
基金This research is funded by ETH Zürich and by the Singapore National Research FoundationThe publication is supported under the Campus for Research Excellence And Technological Enterprise(CREATE)program.
文摘It is our goal to make today’s and future cities smart,sustainable and resilient.In order to achieve this,it is fundamental to understand how each city works,to formalize the knowledge gained and to apply it to a city model as the base for simulations that can generate future scenarios with a high level of probability.The nature of this model,which must cover design,qualitative and quantitative aspects,has changed over time.In this study,we focus on the role of the spatial dimension and of geometry in a city model.Emerging from being a dominating generative force in ancient cities,spatial modeling has developed into an underlying description language for present and future cities to define functions and properties of the city in space and time.The example of the stocks and flows model applied to the city depicts where and how spatial modeling influences the design,construction and performance of the future Smart City.
