Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on lo...Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on local hydrology,climate,biodiversity,and food production[1,2].However,maps,that contain knowledge on the distribution,pattern and composition of various land use types in urban areas,are limited to city level.The mapping standard on data sources,methods,land use classification schemes varies from city to city,due to differences in financial input and skills of mapping personnel.To address various national and global environmental challenges caused by urbanization,it is important to have urban land uses at the national and global scales that are derived from the same or consistent data sources with the same or compatible classification systems and mapping methods.This is because,only with urban land use maps produced with similar criteria,consistent environmental policies can be made,and action efforts can be compared and assessed for large scale environmental administration.However,despite of the fact that a number of urban-extent maps exist at global scales[3,4],more detailed urban land use maps do not exist at the same scale.Even at big country or regional levels such as for the United States,China and European Union,consistent land use mapping efforts are rare[5,6](e.g.,https://sdi4apps.eu/open_land_use/).展开更多
Asthma,rhinitis and eczema(allergic or non-allergic)have increased throughout the world during the last decades,especially among children.Changes in the indoor environment are suspected to be important causes.China ha...Asthma,rhinitis and eczema(allergic or non-allergic)have increased throughout the world during the last decades,especially among children.Changes in the indoor environment are suspected to be important causes.China has experienced a dramatic change in indoor environmental exposures during the past two decades.However,such changes and their associations with children’s asthma and other health aspects have not been thoroughly studied.China,Children,Homes,Health(CCHH),Phase I,was a cross-sectional questionnaire survey of 48219 children 1–8 years old in 10 Chinese cities during 2010–2012.The questionnaire includes the International Study of Asthma and Allergies in Childhood(ISAAC)core health questions and additional questions regarding housing,life habits and outdoor environment.In health analyses,children aged 3–6 years old were included.The prevalences of doctor diagnosed asthma varied from 1.7%to 9.8%(mean 6.8%),a large increase from 0.91%in 1999 and 1.50%in2000.The prevalence of wheeze,rhinitis and atopic eczema(last 12 months)varied from 13.9%to 23.7%,24.0%to 50.8%and4.8%to 15.8%,respectively.Taiyuan had the lowest prevalences of all illnesses and Shanghai the highest,except for wheezewhere the highest value was for Urumqi.We found(1)no obvious association between disease prevalences and ambient PM10concentrations and(2)higher prevalences of disease in humid climates with hot summers and cold winters,but with no centrally heated buildings.Associations between the diseases and economic status as indexed by Gross Domestic Product(GDP)requires further study.展开更多
Heavy metal complexes with high mobility are widely distributed in wastewater from modern industries,which are mo re stable and refracto ry than free heavy metal ions.Their re movals from wastewater draw increasing at...Heavy metal complexes with high mobility are widely distributed in wastewater from modern industries,which are mo re stable and refracto ry than free heavy metal ions.Their re movals from wastewater draw increasing attentions and various technologies have been developed,among which advanced oxidation processes(AOPs)are more effectively and promising.Progresses on five representative types of AOPs,including Fenton(like)oxidation,electrochemical oxidation,photocatalytic oxidation,ozonation and discharge plasma oxidation for heavy metal complexe s degradation are summarized in this review.Their rationales,advantages,applications,challenges and prospects are introduced independently.Combinations among these AOPs,such as electrochemical Fenton oxidation and photoelectrocatalytic oxidation,are also comprehensively highlighted.Future efforts should be made to reduce acid requirement and scale up for practical applications of AOPs for heavy metal complex degradation efficiently and cost-effectively.展开更多
Buildings contribute to almost 30%of total energy consumption worldwide.Developing building energy modeling programs is of great significance for lifecycle building performance assessment and optimization.Advances in ...Buildings contribute to almost 30%of total energy consumption worldwide.Developing building energy modeling programs is of great significance for lifecycle building performance assessment and optimization.Advances in novel building technologies,the requirements of high-performance computation,and the demands for multi-objective models have brought new challenges for building energy modeling software and platforms.To meet the increasing simulation demands,DeST 3.0,a new-generation building performance simulation platform,was developed and released.The structure of DeST 3.0 incorporates four simulation engines,including building analysis and simulation(BAS)engine,HVAC system engine,combined plant simulation(CPS)engine,and energy system(ES)engine,connected by air loop and water loop balancing iterations.DeST 3.0 offers numerous new simulation features,such as advanced simulation modules for building envelopes,occupant behavior and energy systems,cross-platform and compatible simulation kernel,FMI/FMU-based co-simulation functionalities,and high-performance parallel simulation architecture.DeST 3.0 has been thoroughly evaluated and validated using code verification,inter-program comparison,and case-study calibration.DeST 3.0 has been applied in various aspects throughout the building lifecycle,supporting building design,operation,retrofit analysis,code appliance,technology adaptability evaluation as well as research and education.The new generation building simulation platform DeST 3.0 provides an efficient tool and comprehensive simulation platform for lifecycle building performance analysis and optimization.展开更多
Buildings have a significant impact on global sustainability.During the past decades,a wide variety of studies have been conducted throughout the building lifecycle for improving the building performance.Data-driven a...Buildings have a significant impact on global sustainability.During the past decades,a wide variety of studies have been conducted throughout the building lifecycle for improving the building performance.Data-driven approach has been widely adopted owing to less detailed building information required and high computational efficiency for online applications.Recent advances in information technologies and data science have enabled convenient access,storage,and analysis of massive on-site measurements,bringing about a new big-data-driven research paradigm.This paper presents a critical review of data-driven methods,particularly those methods based on larger datasets,for building energy modeling and their practical applications for improving building performances.This paper is organized based on the four essential phases of big-data-driven modeling,i.e.,data preprocessing,model development,knowledge post-processing,and practical applications throughout the building lifecycle.Typical data analysis and application methods have been summarized and compared at each stage,based upon which in-depth discussions and future research directions have been presented.This review demonstrates that the insights obtained from big building data can be extremely helpful for enriching the existing knowledge repository regarding building energy modeling.Furthermore,considering the ever-increasing development of smart buildings and IoT-driven smart cities,the big data-driven research paradigm will become an essential supplement to existing scientific research methods in the building sector.展开更多
Quorum sensing(QS)regulation of the composition of ammonia-oxidising archaea(AOA)and ammonia-oxidising bacteria(AOB)communities and functions in wastewater treatment was investigated.Specifically,we explored the role ...Quorum sensing(QS)regulation of the composition of ammonia-oxidising archaea(AOA)and ammonia-oxidising bacteria(AOB)communities and functions in wastewater treatment was investigated.Specifically,we explored the role of N-acyl-L-homoserine lactones(AHLs)in microbial community dynamics in activated sludge.On average,the specific ammoniaoxidising-rate increased from 1.6 to 2.8 mg NH_4^+-N/g MLSS/hr after treatment with long-chain AHLs for 16 days,and the addition of AHLs to sludge resulted in an increased number of AOA/AOB amoA genes.Significant differences were observed in the AOA communities of control and AHL-treated cultures,but not the AOB community.Furthermore,the dominant functional AOA strains of the Crenarchaeota altered their ecological niche in response to AHL addition.These results provide evidence that AHLs play an important role in mediating AOA/AOB microbial community parameters and demonstrate the potential for application of QS to the regulation of nitrogen compound metabolism in wastewater treatment.展开更多
The combined fouling during ultrafiltration（UF） of surface water pretreated to different extents was investigated to disclose the roles of polysaccharides, proteins, and inorganic particles in UF membrane fouling. B...The combined fouling during ultrafiltration（UF） of surface water pretreated to different extents was investigated to disclose the roles of polysaccharides, proteins, and inorganic particles in UF membrane fouling. Both reversible and irreversible fouling decreased with enhanced pretreatment（biologically active carbon（BAC） treatment and sand filtration）. The sand filter effluent fouled the membrane very slowly. The UF membrane removed turbidity to less than 0.1 nephelometric turbidity unit（NTU）, reduced polysaccharides by 25.4%–29.9%, but rejected few proteins. Both polysaccharides and inorganic particles were detected on the fouled membranes, but inorganic particles could be effectively removed by backwashing. The increase of turbidity in the sand filter effluent to 3.05 NTU did not significantly increase the fouling rate, but an increase in the turbidity in the BAC effluent to6.11 NTU increased the fouling rate by more than 100%. The results demonstrated that the polysaccharide, not the protein, constituents of biopolymers were responsible for membrane fouling. Membrane fouling was closely associated with a small fraction of polysaccharides in the feed water. Inorganic particles exacerbated membrane fouling only when the concentration of fouling–inducing polysaccharides in the feed water was relatively high. The combined fouling was largely reversible, and polysaccharides were the predominant substances responsible for irreversible fouling.展开更多
Bi2MoO6,a typical Bi-based photocatalyst,has received increasing interests and been widely applied in various fields.However,the visible light photocatalytic activity of Bi2MoO6 is still restricted by some obstacles,s...Bi2MoO6,a typical Bi-based photocatalyst,has received increasing interests and been widely applied in various fields.However,the visible light photocatalytic activity of Bi2MoO6 is still restricted by some obstacles,such as limited photo-response and low charge separation efficiency.In this work,we developed a facile method to introduce artificial oxygen vacancy into Bi2MoO6 microspheres,which could effectively address these problems and realize highly efficient visible light photocatalysis.The experimental and theoretical methods were combined to explore the effects of oxygen vacancy on the electronic structure,photocatalytic activity and the reaction mechanism toward NO removal.The results showed that the addition of NaBH4 during catalyst preparation induced the formation of oxygen vacancy in Bi2MoO6,which plays a significant role in extending the visible light absorption of Bi2MoO6.The visible light photocatalytic activity of Bi2MoO6 with oxygen vacancy was obviously enhanced with a NO removal ratio of 43.5%,in contrast to that of 25.0%with the pristine Bi2MoO6.This can be attributed to the oxygen vacancy that creates a defect energy level in the band gap of Bi2MoO6,thus facilitating the charge separation and transfer processes.Hence,more reactive radicals were generated and participated in the photocatalytic NO oxidation reaction.The in situ FT-IR was used to dynamically monitor the photocatalytic NO oxidation process.The reaction intermediates were observed and the adsorption-reaction mechanism was proposed.It was found that the reaction mechanism was unchanged by introducing the oxygen vacancy in Bi2MoO6.This work could provide new insights into the understanding of the oxygen vacancy in photocatalysis and gas-phase photocatalytic reaction mechanism.展开更多
The adsorption of phosphorus （P） onto three industrial solid wastes （fiy ash, red mud and ferric-alum water treatment residual （FAR）） and their modified materials was studied systematically ufa batch experiments...The adsorption of phosphorus （P） onto three industrial solid wastes （fiy ash, red mud and ferric-alum water treatment residual （FAR）） and their modified materials was studied systematically ufa batch experiments. Compared with two natural adsorbents （zeolite and diatomite）, three solid wastes possessed a higher adsorption capacity for P because of the higher Fe, A1 and Ca contents. After modification （i.e., the fly ash and red mud modified by FeC13 and FARs modified by HC1）, the adsorption capacity increased, especially for the modified red mud, where more Fe bonded P was observed. The P adsorption kinetics can be satisfactorily fitted using the pseudo-second-order model. The Langmuir model can describe well the P adsorption on all of the samples in our study, pH and dissolved organic matter （DOM） are two important factors for P adsorption. Under neutral conditions, the maximum adsorption amount on the modified materials was observed. With the deviation from pH 7, the adsorption amount decreased, which resulted from the change of P species in water and surface charges of the adsorbents. The DOM in water can promote P adsorption, which may be due to the promotion effects of humic-Fe（A1） complexes and the pH buffer function exceeds the depression of competitive adsorption.展开更多
The combination of urbanization and global warming leads to urban overheating and compounds the frequency and intensity of extreme heat events due to climate change.Yet,the risk of urban overheating can be mitigated b...The combination of urbanization and global warming leads to urban overheating and compounds the frequency and intensity of extreme heat events due to climate change.Yet,the risk of urban overheating can be mitigated by urban green-blue-grey infrastructure(GBGI),such as parks,wetlands,and engineered greening,which have the potential to effectively reduce summer air temperatures.Despite many reviews,the evidence bases on quantified GBGI cooling benefits remains partial and the practical recommendations for implementation are unclear.This systematic literature review synthesizes the evidence base for heat mitigation and related co-benefits,identifies knowledge gaps,and proposes recommendations for their implementation to maximize their benefits.After screening 27,486 papers,202 were reviewed,based on 51 GBGI types categorized under 10 main divisions.Certain GBGI(green walls,parks,street trees)have been well researched for their urban cooling capabilities.However,several other GBGI have received negligible(zoological garden,golf course,estuary)or minimal(private garden,allotment)attention.The most efficient air cooling was observed in botanical gardens(5.0±3.5℃),wetlands(4.9±3.2℃),green walls(4.1±4.2℃),street trees(3.8±3.1℃),and vegetated balconies(3.8±2.7℃).Under changing climate conditions(2070–2100)with consideration of RCP8.5,there is a shift in climate subtypes,either within the same climate zone(e.g.,Dfa to Dfb and Cfb to Cfa)or across other climate zones(e.g.,Dfb[continental warm-summer humid]to BSk[dry,cold semi-arid]and Cwa[temperate]to Am[tropical]).These shifts may result in lower efficiency for the current GBGI in the future.Given the importance of multiple services,it is crucial to balance their functionality,cooling performance,and other related co-benefits when planning for the future GBGI.This global GBGI heat mitigation inventory can assist policymakers and urban planners in prioritizing effective interventions to reduce the risk of urban overheating,filling research gaps,and promoti展开更多
In recent years,volatile fatty acid(VFA)production through anaerobic fermentation of sewage sludge,instead of methane production,has been regarded as a high-value and promising roadmap for sludge stabilization and res...In recent years,volatile fatty acid(VFA)production through anaerobic fermentation of sewage sludge,instead of methane production,has been regarded as a high-value and promising roadmap for sludge stabilization and resource recovery.This review first presents the effects of some essential factors that influence VFA production and composition.In the second part,we present an extensive analysis of conventional pretreatment and co-fermentation strategies ultimately addressed to improving VFA production and composition.Also,the effectiveness of these approaches is summarized in terms of sludge degradation,hydrolysis rate,and VFA production and composition.According to published studies,it is concluded that some pretreatments such as alkaline and thermal pretreatment are the most effective ways to enhance VFA production from sewage sludge.The possible reasons for the improvement of VFA production by different methods are also discussed.Finally,this review also highlights several current technical challenges and opportunities in VFA production with spectrum control,and further related research is proposed.展开更多
Photothermal catalysis realizes the synergistic effect of solar energy and thermochemistry,which also has the potential to improve the reaction rate and optimize the selectivity.In this review,the research progress of...Photothermal catalysis realizes the synergistic effect of solar energy and thermochemistry,which also has the potential to improve the reaction rate and optimize the selectivity.In this review,the research progress of photothermal catalytic removal of volatile organic compounds(VOCs)by nano-catalysts in recent years is systematically reviewed.First,the fundamentals of photothermal catalysis and the fabrication of catalysts are described,and the design strategy of optimizing photothermal catalysis performance is proposed.Second,the performance for VOC degradation with photothermal catalysis is evaluated and compared for the batch and continuous systems.Particularly,the catalytic mechanism of VOC oxidation is systematically introduced based on experimental and theoretical study.Finally,the future limitations and challenges have been discussed,and potential research directions and priorities are highlighted.A broad view of recent photothermal catalyst fabrication,applications,challenges,and prospects can be systemically provided by this review.展开更多
The plane exposure of support vitally affects the catalytic performance of the catalyst.In this work,CeO_(2)nanorods((110)plane exposure),nano-octahedrons((111)plane exposure)and nano-cubes((100)plane exposure)were pr...The plane exposure of support vitally affects the catalytic performance of the catalyst.In this work,CeO_(2)nanorods((110)plane exposure),nano-octahedrons((111)plane exposure)and nano-cubes((100)plane exposure)were prepared as the supports of Pt/CeO_(2)samples to investigate the effect of CeO_(2)plane exposure on total toluene oxidation.Characterizations reveal that the(110)plane of CeO_(2)is more helpful to the dispersion of Pt species,followed by(111)face.The improved dispersion of Pt species can enhance the metal-supports interaction,which promotes the electron transfer of CeO_(2)carrier to Pt nanoparticles and the adsorption-activation of O_(2),thereby facilitating the total oxidation of toluene via the Langmuir-Hinshelwood(L-H)mechanism.Therefore,Pt/CeO_(2)-r(nanorods)sample expresses excellent catalytic performance of toluene oxidation.Finally,the procedure of toluene total oxidation was studied by in-situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy.We expect that this work can contribute to the development of an effective sample for the decomposition of volatile organic compounds(VOCs).展开更多
With the development in photocatalysis field,photocatalysts have received increasing attention due to their important role in environmental pollution and energy crisis.As a nonmetallic photocatalyst,graphitic carbon n...With the development in photocatalysis field,photocatalysts have received increasing attention due to their important role in environmental pollution and energy crisis.As a nonmetallic photocatalyst,graphitic carbon nitride(g-C3N4)has been widely recognized because of its excellent optical properties,low cost,and environment friendliness.In the g-C3N4 intrinsic frameworks,carbon atom tends to be the reducing active site,while nitrogen atom tends to be the oxidizing active site and reducing active site according to the difference of electronegativity.However,the quantity and quality of these active sites are affected by many factors,including C N covalent bonds,surface properties,etc.Active sites play an important role in photocatalysis;however,this role is not detailed in most reports.In this review,we proposed the following possible mechanisms of active sites in improving the photocatalytic activity of traditional g-C_(3)N_(4) based on its intrinsic:morphology regulation,carrier migration,surface active treatment,and substrate adsorption.The following factors affecting the active sites of g-C_(3)N_(4),including basal engineering and hybrid engineering,were also investigated.The roles of these active sites in improving the photocatalytic activity of g-C_(3)N_(4)-based photocatalytic materials,including morphology regulation,surface treatment,heteroatom doping,and interfacial interaction,were also expounded.Current challenges and future development of g-C_(3)N_(4)-based photocatalysts that are rich in active surface sites were also discussed.This review provides an in-depth understanding of g-C_(3)N_(4)-based photocatalysts.展开更多
Global climate change,growing population,and environmental pollution underscore the need for a greater focus on providing advanced water treatment technologies.Although electrochemical basedprocesses are becoming prom...Global climate change,growing population,and environmental pollution underscore the need for a greater focus on providing advanced water treatment technologies.Although electrochemical basedprocesses are becoming promising solutions,they still face challenges owing to mass transport and upscaling which hinder the exploitation of this technology.Electrode design and reactor configuration are key factors for achieving operational improvements.The electroactive membrane has proven to be a breakthrough technology integrating electrochemistry and membrane separation with an enhanced mass transport by convection.In this review article,we discuss recent progress in environmental applications of electroactive membranes with particular focus on those composed of carbon nanotubes(CNT)due to their intriguing physicochemical prope rties.Their applications in degradation of refractory contaminants,detoxification and sequestration of toxic heavy metal ions,and membrane fouling alleviations are systematically reviewed.We then discuss the existing limitations and opportunities for future research.The development of advanced electroactive systems depends on interdisciplinary collaborations in the areas of materials,electrochemistry,membrane development,and environmental sciences.展开更多
The high population and concrete environment alter urban areas by changing temperature, rainfall runoff, and water resource utilization activities. This study was conducted to investigate the water quality features of...The high population and concrete environment alter urban areas by changing temperature, rainfall runoff, and water resource utilization activities. This study was conducted to investigate the water quality features of the Yongding Diversion Channel in Beijing, China, and its relationship with rainfall and urban development. Monthly water quality data were obtained from April to October of 2004 at monitoring sites of Sanjiadian, Gaojing, Luodaozhuang, and Yuyuangtan. The monthly water quality grades from 2007 to 2011 were also investigated and compared with those of other rivers. Dissolved oxygen and pH showed greater decreases after one or two moderate rainfall events than several light rainfall events. The potassium permanganate index （CODMn）, ammonia nitrogen （NH3-N） and total phosphorus （TP） increased more after several light rainfall events than after one or two moderate or heavy rainfall events. Pollutant concentrations （CODMn, NH3-N, TP） in downstream regions showed greater changes than those in upstream areas after heavy rainfall events. Intense human activities around the channel greatly influenced the water quality of the channel in rainy season because of runoff pollution; however, heavy rainfall had a strong dilution effect on the pollutant concentrations in rivers. Overall, urban development has obviously deteriorated the water quality of the Yongding Diversion Channel as indicated by an increase in the water quality index from 3.22 in 2008 to 4.55 in 2010. The Pearson correlation between monthly rainfall and water quality indices from 2007 to 2011 ranged from 0.1286 to 0.6968, generally becoming weaker as rainfall and rainfall runoff became more random and extreme.展开更多
With the acceleration of urbanization,changes in the urban ecological environment and landscape pattern have led to a series of prominent ecological environmental problems.In order to better coordinate the balanced re...With the acceleration of urbanization,changes in the urban ecological environment and landscape pattern have led to a series of prominent ecological environmental problems.In order to better coordinate the balanced relationship between city and ecological environment,we selected land use change data to evaluate the habitat quality in Hohhot City of China,which is of great practical significance for regional urban and economic development.Thus,the integrated valuation of ecosystem services and tradeoffs(InVEST)and Cellular Automata-Markov(CA-Markov)models were used to analyze,predict,and explore the Spatiotemporal evolution path and characteristics of urban land use,and forecast the typical evolution pattern of land use in 2030.The results showed that the land use types in Hohhot City changed significantly from 2000 to 2020,and the biggest change took place in cultivated land,grassland,shrub,and artificial surface.The decrease of cultivated land area and the increase of artificial surface area were the main impact trend of land use change.The average value of habitat quality had been decreasing continuously from 2000 to 2020,and the values of habitat degradation were 0.2605,0.2494,and 0.2934 in 2000,2010,and 2020,respectively,showing a decreasing trend.The decrease of habitat quality was caused by the needs of economic development and urban construction,as well as the impact of land occupation.During this evolution,many cultivated land and urban grassland had been converted into construction land.The simulated land use changes in 2030 are basically the same as those during 2000-2020,and the habitat quality will still be declining.The regional changes are influenced by the urban rapid development and industrial layout.These results can provide decision-making reference for regional urban planning and management as well as habitat quality evaluation.展开更多
Lane-changing is performed either to follow the route to a planned destination(i.e.,mandatory lane-changing)or to achieve better driving conditions(i.e.,discretionary lane-changing).A connected environment is expected...Lane-changing is performed either to follow the route to a planned destination(i.e.,mandatory lane-changing)or to achieve better driving conditions(i.e.,discretionary lane-changing).A connected environment is expected to assist during lane-changing manoeuvres,but it is not known well how driving aids in a connected environment assist lane-changing execution.As such,this study investigates the impact of a connected environment on lanechanging execution time during mandatory and discretionary lane-changing manoeuvres.To this end,this study designed an advanced driving simulator experiment where 78 drivers performed these manoeuvres on a simulated motorway in three randomised driving conditions.The conditions were baseline(without driving aids),a fully functioning connected environment with a perfect supply of driving aids,and an impaired connected environment with delayed driving aids.The lane-changing execution time has been modelled by a random parameters hazard-based duration modelling approach,which accounts for the panel nature of data and captures the unobserved heterogeneity.Results suggest that,compared to the baseline condition(i.e.,a non-connected environment),most of the drivers in the connected environment take more time to complete their lane-changing manoeuvres,indicating drivers’safer lane-changing execution behaviour in the connected environment.The communication delay driving condition has been found to have more deteriorating effects on mandatory lanechanging manoeuvres than discretionary lane-changing manoeuvres.This study concludes that(i)the connected environment increases safety margin during both lane-changing manoeuvres,and(ii)a higher magnitude of safety margin is observed during mandatory lane-changing manoeuvres whereby drivers have a higher need for assistance.展开更多
基金partially supported by the National Key Research and Development Program of China(2016YFA0600104)supported by donations made by Delos Living LLC,and the Cyrus Tang Foundation+2 种基金supported by the National Natural Science Foundation of China(41471419)Beijing Institute of Urban Planningsupported by the Fundamental Research Funds for the Central Universities(CCNU19TD002).
文摘Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on local hydrology,climate,biodiversity,and food production[1,2].However,maps,that contain knowledge on the distribution,pattern and composition of various land use types in urban areas,are limited to city level.The mapping standard on data sources,methods,land use classification schemes varies from city to city,due to differences in financial input and skills of mapping personnel.To address various national and global environmental challenges caused by urbanization,it is important to have urban land uses at the national and global scales that are derived from the same or consistent data sources with the same or compatible classification systems and mapping methods.This is because,only with urban land use maps produced with similar criteria,consistent environmental policies can be made,and action efforts can be compared and assessed for large scale environmental administration.However,despite of the fact that a number of urban-extent maps exist at global scales[3,4],more detailed urban land use maps do not exist at the same scale.Even at big country or regional levels such as for the United States,China and European Union,consistent land use mapping efforts are rare[5,6](e.g.,https://sdi4apps.eu/open_land_use/).
基金supported by the National Natural Science Foundation of China(51136002,51076079,51006057)Ministry of Science and Technology of China(2012BAJ02B03)National High Technology Research and Development Program of China(2010AA064903)
文摘Asthma,rhinitis and eczema(allergic or non-allergic)have increased throughout the world during the last decades,especially among children.Changes in the indoor environment are suspected to be important causes.China has experienced a dramatic change in indoor environmental exposures during the past two decades.However,such changes and their associations with children’s asthma and other health aspects have not been thoroughly studied.China,Children,Homes,Health(CCHH),Phase I,was a cross-sectional questionnaire survey of 48219 children 1–8 years old in 10 Chinese cities during 2010–2012.The questionnaire includes the International Study of Asthma and Allergies in Childhood(ISAAC)core health questions and additional questions regarding housing,life habits and outdoor environment.In health analyses,children aged 3–6 years old were included.The prevalences of doctor diagnosed asthma varied from 1.7%to 9.8%(mean 6.8%),a large increase from 0.91%in 1999 and 1.50%in2000.The prevalence of wheeze,rhinitis and atopic eczema(last 12 months)varied from 13.9%to 23.7%,24.0%to 50.8%and4.8%to 15.8%,respectively.Taiyuan had the lowest prevalences of all illnesses and Shanghai the highest,except for wheezewhere the highest value was for Urumqi.We found(1)no obvious association between disease prevalences and ambient PM10concentrations and(2)higher prevalences of disease in humid climates with hot summers and cold winters,but with no centrally heated buildings.Associations between the diseases and economic status as indexed by Gross Domestic Product(GDP)requires further study.
基金the National Natural Science Foundation of China(NSFC)(No.41672237)the Beijing Natural Science Foundation(No.8192040)。
文摘Heavy metal complexes with high mobility are widely distributed in wastewater from modern industries,which are mo re stable and refracto ry than free heavy metal ions.Their re movals from wastewater draw increasing attentions and various technologies have been developed,among which advanced oxidation processes(AOPs)are more effectively and promising.Progresses on five representative types of AOPs,including Fenton(like)oxidation,electrochemical oxidation,photocatalytic oxidation,ozonation and discharge plasma oxidation for heavy metal complexe s degradation are summarized in this review.Their rationales,advantages,applications,challenges and prospects are introduced independently.Combinations among these AOPs,such as electrochemical Fenton oxidation and photoelectrocatalytic oxidation,are also comprehensively highlighted.Future efforts should be made to reduce acid requirement and scale up for practical applications of AOPs for heavy metal complex degradation efficiently and cost-effectively.
基金supported by the“13th Five-Year”National Key R&D Program of China(No.2017YFC0702200)。
文摘Buildings contribute to almost 30%of total energy consumption worldwide.Developing building energy modeling programs is of great significance for lifecycle building performance assessment and optimization.Advances in novel building technologies,the requirements of high-performance computation,and the demands for multi-objective models have brought new challenges for building energy modeling software and platforms.To meet the increasing simulation demands,DeST 3.0,a new-generation building performance simulation platform,was developed and released.The structure of DeST 3.0 incorporates four simulation engines,including building analysis and simulation(BAS)engine,HVAC system engine,combined plant simulation(CPS)engine,and energy system(ES)engine,connected by air loop and water loop balancing iterations.DeST 3.0 offers numerous new simulation features,such as advanced simulation modules for building envelopes,occupant behavior and energy systems,cross-platform and compatible simulation kernel,FMI/FMU-based co-simulation functionalities,and high-performance parallel simulation architecture.DeST 3.0 has been thoroughly evaluated and validated using code verification,inter-program comparison,and case-study calibration.DeST 3.0 has been applied in various aspects throughout the building lifecycle,supporting building design,operation,retrofit analysis,code appliance,technology adaptability evaluation as well as research and education.The new generation building simulation platform DeST 3.0 provides an efficient tool and comprehensive simulation platform for lifecycle building performance analysis and optimization.
基金The authors gratefully acknowledge the support of this research by the Research Grant Council of Hong Kong SAR(152075/19E)the National Natural Science Foundation of China(No.51908365)the National Natural Science Foundation of China(No.51778321).
文摘Buildings have a significant impact on global sustainability.During the past decades,a wide variety of studies have been conducted throughout the building lifecycle for improving the building performance.Data-driven approach has been widely adopted owing to less detailed building information required and high computational efficiency for online applications.Recent advances in information technologies and data science have enabled convenient access,storage,and analysis of massive on-site measurements,bringing about a new big-data-driven research paradigm.This paper presents a critical review of data-driven methods,particularly those methods based on larger datasets,for building energy modeling and their practical applications for improving building performances.This paper is organized based on the four essential phases of big-data-driven modeling,i.e.,data preprocessing,model development,knowledge post-processing,and practical applications throughout the building lifecycle.Typical data analysis and application methods have been summarized and compared at each stage,based upon which in-depth discussions and future research directions have been presented.This review demonstrates that the insights obtained from big building data can be extremely helpful for enriching the existing knowledge repository regarding building energy modeling.Furthermore,considering the ever-increasing development of smart buildings and IoT-driven smart cities,the big data-driven research paradigm will become an essential supplement to existing scientific research methods in the building sector.
基金supported by the National Natural Science Foundation of China (No. 41501250)the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB15030101)the National Key Research and Development Program of China (Nos. 2016YFC0500401 and 2017YFC050580301)
文摘Quorum sensing(QS)regulation of the composition of ammonia-oxidising archaea(AOA)and ammonia-oxidising bacteria(AOB)communities and functions in wastewater treatment was investigated.Specifically,we explored the role of N-acyl-L-homoserine lactones(AHLs)in microbial community dynamics in activated sludge.On average,the specific ammoniaoxidising-rate increased from 1.6 to 2.8 mg NH_4^+-N/g MLSS/hr after treatment with long-chain AHLs for 16 days,and the addition of AHLs to sludge resulted in an increased number of AOA/AOB amoA genes.Significant differences were observed in the AOA communities of control and AHL-treated cultures,but not the AOB community.Furthermore,the dominant functional AOA strains of the Crenarchaeota altered their ecological niche in response to AHL addition.These results provide evidence that AHLs play an important role in mediating AOA/AOB microbial community parameters and demonstrate the potential for application of QS to the regulation of nitrogen compound metabolism in wastewater treatment.
基金supported by the China Major Science and Technology Program for Water Pollution Control and Treatment (No. 2012ZX07404-002)
文摘The combined fouling during ultrafiltration（UF） of surface water pretreated to different extents was investigated to disclose the roles of polysaccharides, proteins, and inorganic particles in UF membrane fouling. Both reversible and irreversible fouling decreased with enhanced pretreatment（biologically active carbon（BAC） treatment and sand filtration）. The sand filter effluent fouled the membrane very slowly. The UF membrane removed turbidity to less than 0.1 nephelometric turbidity unit（NTU）, reduced polysaccharides by 25.4%–29.9%, but rejected few proteins. Both polysaccharides and inorganic particles were detected on the fouled membranes, but inorganic particles could be effectively removed by backwashing. The increase of turbidity in the sand filter effluent to 3.05 NTU did not significantly increase the fouling rate, but an increase in the turbidity in the BAC effluent to6.11 NTU increased the fouling rate by more than 100%. The results demonstrated that the polysaccharide, not the protein, constituents of biopolymers were responsible for membrane fouling. Membrane fouling was closely associated with a small fraction of polysaccharides in the feed water. Inorganic particles exacerbated membrane fouling only when the concentration of fouling–inducing polysaccharides in the feed water was relatively high. The combined fouling was largely reversible, and polysaccharides were the predominant substances responsible for irreversible fouling.
基金supported by the National Natural Science Foundation of China(21501016,51501024,51871037 and 21822601)the Fundamental Research Funds for the Central Universities(2018CDQYCL0027)~~
文摘Bi2MoO6,a typical Bi-based photocatalyst,has received increasing interests and been widely applied in various fields.However,the visible light photocatalytic activity of Bi2MoO6 is still restricted by some obstacles,such as limited photo-response and low charge separation efficiency.In this work,we developed a facile method to introduce artificial oxygen vacancy into Bi2MoO6 microspheres,which could effectively address these problems and realize highly efficient visible light photocatalysis.The experimental and theoretical methods were combined to explore the effects of oxygen vacancy on the electronic structure,photocatalytic activity and the reaction mechanism toward NO removal.The results showed that the addition of NaBH4 during catalyst preparation induced the formation of oxygen vacancy in Bi2MoO6,which plays a significant role in extending the visible light absorption of Bi2MoO6.The visible light photocatalytic activity of Bi2MoO6 with oxygen vacancy was obviously enhanced with a NO removal ratio of 43.5%,in contrast to that of 25.0%with the pristine Bi2MoO6.This can be attributed to the oxygen vacancy that creates a defect energy level in the band gap of Bi2MoO6,thus facilitating the charge separation and transfer processes.Hence,more reactive radicals were generated and participated in the photocatalytic NO oxidation reaction.The in situ FT-IR was used to dynamically monitor the photocatalytic NO oxidation process.The reaction intermediates were observed and the adsorption-reaction mechanism was proposed.It was found that the reaction mechanism was unchanged by introducing the oxygen vacancy in Bi2MoO6.This work could provide new insights into the understanding of the oxygen vacancy in photocatalysis and gas-phase photocatalytic reaction mechanism.
基金supported by the National Natural Science Foundation of China (Nos. 51578070, 21177013)the International Science & Technology Cooperation Program of China (No. 2013DFR90290)+1 种基金support from the Brook Byers Institute for Sustainable SystemsHightower Chair and Georgia Research Alliance at Georgia Institute of Technology
文摘The adsorption of phosphorus （P） onto three industrial solid wastes （fiy ash, red mud and ferric-alum water treatment residual （FAR）） and their modified materials was studied systematically ufa batch experiments. Compared with two natural adsorbents （zeolite and diatomite）, three solid wastes possessed a higher adsorption capacity for P because of the higher Fe, A1 and Ca contents. After modification （i.e., the fly ash and red mud modified by FeC13 and FARs modified by HC1）, the adsorption capacity increased, especially for the modified red mud, where more Fe bonded P was observed. The P adsorption kinetics can be satisfactorily fitted using the pseudo-second-order model. The Langmuir model can describe well the P adsorption on all of the samples in our study, pH and dissolved organic matter （DOM） are two important factors for P adsorption. Under neutral conditions, the maximum adsorption amount on the modified materials was observed. With the deviation from pH 7, the adsorption amount decreased, which resulted from the change of P species in water and surface charges of the adsorbents. The DOM in water can promote P adsorption, which may be due to the promotion effects of humic-Fe（A1） complexes and the pH buffer function exceeds the depression of competitive adsorption.
基金This work has been commissioned by the UKRI(EPSRC,NERC,AHRC)funded by RECLAIM Network Plus project(EP/W034034/1,EP/W033984)under its synthesis review seriesThe following authors acknowledge the funding received through their grants:P.K.and L.J.(NE/X002799/1,NE/X002772/1),L.J.(H2020 REGREEN,EU Grant agreement No.821016,2021YFE93100),G.M.L.(FAPESP 2019/08783-0),C.D.F.R.(EP/R017727),L.M.(ARC Grant No.IC220100012),H.G.(RGC Grant No.C5024-21G),M.F.A.and E.D.F.(FAPESP Grant No.2016/18438-0,2022/02365-5),S.J.C.(NSFC Grant No.52225005),R.Y.(NSFC Grant No.52278090),F.W.(NKP Grant No.2020YFC180700),J.E.(NE/X000443/1),and F.C.(NE/M010961/1,NE/V002171/1).The authors thank Andrea Sofia Majjul Fajardo for her contribution to the initial design of certain figures.We also thank the team members of GCARE and its Guildford Living Lab(GLL),as well as the participants in the RECLAIM Network Plus Horizon Scanning Workshop.
文摘The combination of urbanization and global warming leads to urban overheating and compounds the frequency and intensity of extreme heat events due to climate change.Yet,the risk of urban overheating can be mitigated by urban green-blue-grey infrastructure(GBGI),such as parks,wetlands,and engineered greening,which have the potential to effectively reduce summer air temperatures.Despite many reviews,the evidence bases on quantified GBGI cooling benefits remains partial and the practical recommendations for implementation are unclear.This systematic literature review synthesizes the evidence base for heat mitigation and related co-benefits,identifies knowledge gaps,and proposes recommendations for their implementation to maximize their benefits.After screening 27,486 papers,202 were reviewed,based on 51 GBGI types categorized under 10 main divisions.Certain GBGI(green walls,parks,street trees)have been well researched for their urban cooling capabilities.However,several other GBGI have received negligible(zoological garden,golf course,estuary)or minimal(private garden,allotment)attention.The most efficient air cooling was observed in botanical gardens(5.0±3.5℃),wetlands(4.9±3.2℃),green walls(4.1±4.2℃),street trees(3.8±3.1℃),and vegetated balconies(3.8±2.7℃).Under changing climate conditions(2070–2100)with consideration of RCP8.5,there is a shift in climate subtypes,either within the same climate zone(e.g.,Dfa to Dfb and Cfb to Cfa)or across other climate zones(e.g.,Dfb[continental warm-summer humid]to BSk[dry,cold semi-arid]and Cwa[temperate]to Am[tropical]).These shifts may result in lower efficiency for the current GBGI in the future.Given the importance of multiple services,it is crucial to balance their functionality,cooling performance,and other related co-benefits when planning for the future GBGI.This global GBGI heat mitigation inventory can assist policymakers and urban planners in prioritizing effective interventions to reduce the risk of urban overheating,filling research gaps,and promoti
基金supported by the National Natural Science Foundation of China(No.51578068)"One Thousand Talent Plan" Youth Program
文摘In recent years,volatile fatty acid(VFA)production through anaerobic fermentation of sewage sludge,instead of methane production,has been regarded as a high-value and promising roadmap for sludge stabilization and resource recovery.This review first presents the effects of some essential factors that influence VFA production and composition.In the second part,we present an extensive analysis of conventional pretreatment and co-fermentation strategies ultimately addressed to improving VFA production and composition.Also,the effectiveness of these approaches is summarized in terms of sludge degradation,hydrolysis rate,and VFA production and composition.According to published studies,it is concluded that some pretreatments such as alkaline and thermal pretreatment are the most effective ways to enhance VFA production from sewage sludge.The possible reasons for the improvement of VFA production by different methods are also discussed.Finally,this review also highlights several current technical challenges and opportunities in VFA production with spectrum control,and further related research is proposed.
基金sponsored financially by the National Natural Science Foundation of China (No.21906104 and No.12175145)the Shanghai Rising-Star Program (21QA1406600).
文摘Photothermal catalysis realizes the synergistic effect of solar energy and thermochemistry,which also has the potential to improve the reaction rate and optimize the selectivity.In this review,the research progress of photothermal catalytic removal of volatile organic compounds(VOCs)by nano-catalysts in recent years is systematically reviewed.First,the fundamentals of photothermal catalysis and the fabrication of catalysts are described,and the design strategy of optimizing photothermal catalysis performance is proposed.Second,the performance for VOC degradation with photothermal catalysis is evaluated and compared for the batch and continuous systems.Particularly,the catalytic mechanism of VOC oxidation is systematically introduced based on experimental and theoretical study.Finally,the future limitations and challenges have been discussed,and potential research directions and priorities are highlighted.A broad view of recent photothermal catalyst fabrication,applications,challenges,and prospects can be systemically provided by this review.
基金Project supported by the Natural Science Foundation for the Higher Education Institutions of Anhui Province of China(KJ2020A0236,KJ2018A0638,KJ2019A0079)。
文摘The plane exposure of support vitally affects the catalytic performance of the catalyst.In this work,CeO_(2)nanorods((110)plane exposure),nano-octahedrons((111)plane exposure)and nano-cubes((100)plane exposure)were prepared as the supports of Pt/CeO_(2)samples to investigate the effect of CeO_(2)plane exposure on total toluene oxidation.Characterizations reveal that the(110)plane of CeO_(2)is more helpful to the dispersion of Pt species,followed by(111)face.The improved dispersion of Pt species can enhance the metal-supports interaction,which promotes the electron transfer of CeO_(2)carrier to Pt nanoparticles and the adsorption-activation of O_(2),thereby facilitating the total oxidation of toluene via the Langmuir-Hinshelwood(L-H)mechanism.Therefore,Pt/CeO_(2)-r(nanorods)sample expresses excellent catalytic performance of toluene oxidation.Finally,the procedure of toluene total oxidation was studied by in-situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy.We expect that this work can contribute to the development of an effective sample for the decomposition of volatile organic compounds(VOCs).
基金financially supported by the National Natural Science Foundation of China(Nos.51672099 and 21403079)the Sichuan Science and Technology Program(No.2019JDRC0027)the Fundamental Research Funds for the Central Universities(No.2017-QR-25)。
文摘With the development in photocatalysis field,photocatalysts have received increasing attention due to their important role in environmental pollution and energy crisis.As a nonmetallic photocatalyst,graphitic carbon nitride(g-C3N4)has been widely recognized because of its excellent optical properties,low cost,and environment friendliness.In the g-C3N4 intrinsic frameworks,carbon atom tends to be the reducing active site,while nitrogen atom tends to be the oxidizing active site and reducing active site according to the difference of electronegativity.However,the quantity and quality of these active sites are affected by many factors,including C N covalent bonds,surface properties,etc.Active sites play an important role in photocatalysis;however,this role is not detailed in most reports.In this review,we proposed the following possible mechanisms of active sites in improving the photocatalytic activity of traditional g-C_(3)N_(4) based on its intrinsic:morphology regulation,carrier migration,surface active treatment,and substrate adsorption.The following factors affecting the active sites of g-C_(3)N_(4),including basal engineering and hybrid engineering,were also investigated.The roles of these active sites in improving the photocatalytic activity of g-C_(3)N_(4)-based photocatalytic materials,including morphology regulation,surface treatment,heteroatom doping,and interfacial interaction,were also expounded.Current challenges and future development of g-C_(3)N_(4)-based photocatalysts that are rich in active surface sites were also discussed.This review provides an in-depth understanding of g-C_(3)N_(4)-based photocatalysts.
基金the Natural Science Foundation of Shanghai,China(No.18ZR1401000)the Shanghai Pujiang Program(No.18PJ1400400)Donghua University for the start-up grant(No.113-07-005710)。
文摘Global climate change,growing population,and environmental pollution underscore the need for a greater focus on providing advanced water treatment technologies.Although electrochemical basedprocesses are becoming promising solutions,they still face challenges owing to mass transport and upscaling which hinder the exploitation of this technology.Electrode design and reactor configuration are key factors for achieving operational improvements.The electroactive membrane has proven to be a breakthrough technology integrating electrochemistry and membrane separation with an enhanced mass transport by convection.In this review article,we discuss recent progress in environmental applications of electroactive membranes with particular focus on those composed of carbon nanotubes(CNT)due to their intriguing physicochemical prope rties.Their applications in degradation of refractory contaminants,detoxification and sequestration of toxic heavy metal ions,and membrane fouling alleviations are systematically reviewed.We then discuss the existing limitations and opportunities for future research.The development of advanced electroactive systems depends on interdisciplinary collaborations in the areas of materials,electrochemistry,membrane development,and environmental sciences.
基金This work was supported by the International Research Center of Big Data for Sustainable Development Goals,the National Natural Science Foundation of China(42271422 and 41930648)the Open Fund of Key Laboratory of Urban Land Resources Monitoring and Simulation,Ministry of Natural Resources(KF-2020-05-025).
基金supported by the National Science Foundation for Innovative Research Group (No. 51121003)the Open Research Fund Program of Key Laboratory of Urban Stormwater System and Water Environment (BUCEA)+1 种基金the National Science Foundation of China (No. 51278054)the FST Short Term PD & VF Scheme 2013 and MYRG072(Y1-L2)-FST13-LIC from University of Macao
文摘The high population and concrete environment alter urban areas by changing temperature, rainfall runoff, and water resource utilization activities. This study was conducted to investigate the water quality features of the Yongding Diversion Channel in Beijing, China, and its relationship with rainfall and urban development. Monthly water quality data were obtained from April to October of 2004 at monitoring sites of Sanjiadian, Gaojing, Luodaozhuang, and Yuyuangtan. The monthly water quality grades from 2007 to 2011 were also investigated and compared with those of other rivers. Dissolved oxygen and pH showed greater decreases after one or two moderate rainfall events than several light rainfall events. The potassium permanganate index （CODMn）, ammonia nitrogen （NH3-N） and total phosphorus （TP） increased more after several light rainfall events than after one or two moderate or heavy rainfall events. Pollutant concentrations （CODMn, NH3-N, TP） in downstream regions showed greater changes than those in upstream areas after heavy rainfall events. Intense human activities around the channel greatly influenced the water quality of the channel in rainy season because of runoff pollution; however, heavy rainfall had a strong dilution effect on the pollutant concentrations in rivers. Overall, urban development has obviously deteriorated the water quality of the Yongding Diversion Channel as indicated by an increase in the water quality index from 3.22 in 2008 to 4.55 in 2010. The Pearson correlation between monthly rainfall and water quality indices from 2007 to 2011 ranged from 0.1286 to 0.6968, generally becoming weaker as rainfall and rainfall runoff became more random and extreme.
基金The authors thank anonymous reviewers and editors for their helpful comments on improving the quality of this manuscript.
文摘With the acceleration of urbanization,changes in the urban ecological environment and landscape pattern have led to a series of prominent ecological environmental problems.In order to better coordinate the balanced relationship between city and ecological environment,we selected land use change data to evaluate the habitat quality in Hohhot City of China,which is of great practical significance for regional urban and economic development.Thus,the integrated valuation of ecosystem services and tradeoffs(InVEST)and Cellular Automata-Markov(CA-Markov)models were used to analyze,predict,and explore the Spatiotemporal evolution path and characteristics of urban land use,and forecast the typical evolution pattern of land use in 2030.The results showed that the land use types in Hohhot City changed significantly from 2000 to 2020,and the biggest change took place in cultivated land,grassland,shrub,and artificial surface.The decrease of cultivated land area and the increase of artificial surface area were the main impact trend of land use change.The average value of habitat quality had been decreasing continuously from 2000 to 2020,and the values of habitat degradation were 0.2605,0.2494,and 0.2934 in 2000,2010,and 2020,respectively,showing a decreasing trend.The decrease of habitat quality was caused by the needs of economic development and urban construction,as well as the impact of land occupation.During this evolution,many cultivated land and urban grassland had been converted into construction land.The simulated land use changes in 2030 are basically the same as those during 2000-2020,and the habitat quality will still be declining.The regional changes are influenced by the urban rapid development and industrial layout.These results can provide decision-making reference for regional urban planning and management as well as habitat quality evaluation.
基金partly funded by the Australian Research Council grant DP210102970.
文摘Lane-changing is performed either to follow the route to a planned destination(i.e.,mandatory lane-changing)or to achieve better driving conditions(i.e.,discretionary lane-changing).A connected environment is expected to assist during lane-changing manoeuvres,but it is not known well how driving aids in a connected environment assist lane-changing execution.As such,this study investigates the impact of a connected environment on lanechanging execution time during mandatory and discretionary lane-changing manoeuvres.To this end,this study designed an advanced driving simulator experiment where 78 drivers performed these manoeuvres on a simulated motorway in three randomised driving conditions.The conditions were baseline(without driving aids),a fully functioning connected environment with a perfect supply of driving aids,and an impaired connected environment with delayed driving aids.The lane-changing execution time has been modelled by a random parameters hazard-based duration modelling approach,which accounts for the panel nature of data and captures the unobserved heterogeneity.Results suggest that,compared to the baseline condition(i.e.,a non-connected environment),most of the drivers in the connected environment take more time to complete their lane-changing manoeuvres,indicating drivers’safer lane-changing execution behaviour in the connected environment.The communication delay driving condition has been found to have more deteriorating effects on mandatory lanechanging manoeuvres than discretionary lane-changing manoeuvres.This study concludes that(i)the connected environment increases safety margin during both lane-changing manoeuvres,and(ii)a higher magnitude of safety margin is observed during mandatory lane-changing manoeuvres whereby drivers have a higher need for assistance.
