With the rise of smart phones,mobile applications have been widely used in daily life.However,the relationship between individuals’mobile application usage and cities’economic development has yet to be investigated....With the rise of smart phones,mobile applications have been widely used in daily life.However,the relationship between individuals’mobile application usage and cities’economic development has yet to be investigated.To study this question,this work utilizes a dataset containing users’history of mobile application usage records(MAURs)and investigates how MAURs are related to Chinese cities’economic development.Our analysis shows the cities’GDP and number of MAURs are highly correlated,and at the individual level,people in wealthier cities(higher GDP per capita)tend to have more active mobile application usage(MAURs per capita).The results also demonstrate the relevance between cities’GDP and MAURs varies significantly among different demographic groups,with male users’relevance consistently higher than female users’and working-age people’s relevance higher than other age groups.A boosted tree regression model is then applied to predict cities’GDP with MAURs and proves to achieve high goodness-of-fit(over 0.8 R-square)and good prediction accuracy,especially for the economically developed and populous regions in China.To the best of our knowledge,this is the first time that the relationship between MAURs and cities’economic development is revealed,which contributes to novel knowledge discovery for regionalization and urban development.展开更多
Electrolysis is a promising technology to improve sludge dewaterability efficiently with negligible environmental impact. To intensify the electrolytic efficiency, the effect of electrolytes(NaCl, Na_2SO_4, NaNO_3, an...Electrolysis is a promising technology to improve sludge dewaterability efficiently with negligible environmental impact. To intensify the electrolytic efficiency, the effect of electrolytes(NaCl, Na_2SO_4, NaNO_3, and NaClO_4) on electrolysis pretreatment of municipal sludge and its mechanisms was investigated using Ti/PbO_2 electrodes. The electrolytes,which enhanced the production of oxidative radicals, showed a significant synergetic effect in reducing the capillary suction time(CST) of sludge. NaCl was distinguished from the other electrolytes since it formed a large amount of active chlorine species, which oxidized the sludge cells to improve the sludge dewaterability. The surface morphologies as well as the soluble proteins and polysaccharides were analyzed to unravel the underlying mechanisms of sludge dewaterability. Additionally, an economic assessment showed that NaCl addition in the electrolysis pretreatment can be a suitable technique for enhancing municipal sludge dewaterability.展开更多
The effect of soil stratification was studied through numerical investigation based on the coupled model of solute transport in deformable unsaturated soil. The theoretical model implied two-way coupled excess pore pr...The effect of soil stratification was studied through numerical investigation based on the coupled model of solute transport in deformable unsaturated soil. The theoretical model implied two-way coupled excess pore pressure and soil deformation based on Biot's consolidation theory as well as a one-way coupled volatile pollutant concentration field developed from the advection-diffusion theory. Embedded in the model, the degree of saturation, fluid compressibility, self-weight of the soil matrix, porosity variance, longitudinal dispersion, and linear sorption were computed. Based on simulation results of a proposed three-layer landfill model using the finite element method, the multi-layer effects are discussed with regard to the hydraulic conductivity, shear modulus, degree of saturation, molecular diffusion coefficient, and thickness of each layer. Generally speaking, contaminants spread faster in a stratified field with a soft and highly permeable top layer; soil parameters of the top layer are more critical than the lower layers but controlling soil thicknesses will alter the results. This numerical investigation showed noticeable impacts of stratified soil properties on solute migration results, demonstrating the importance of correctly modeling layered soil instead of simply assuming the averaged properties across the soil profile.展开更多
Taking Poyang Lake Eco-economic Zone as an example,we analyzed existing problems in China'forest resource protection from the perspective of legal system.The problems include unclear property right system of fores...Taking Poyang Lake Eco-economic Zone as an example,we analyzed existing problems in China'forest resource protection from the perspective of legal system.The problems include unclear property right system of forest resource,imperfect compensation mechanism for forest ecology,forest cutting quota scheme not resolutely put into practice,legal supervision of forest protection not implemented,and lack of integration in forest protection laws.Based on these problems,we put forward countermeasures and suggestions:establish clear forest resource property system;improve ecological benefit compensation mechanism in legal form;strictly implement forest cutting quota scheme;strengthen legal supervision of forest protection;and keep legal system integral for forest resource protection.展开更多
The research of superhydrophobic materials has attracted many researchers＇ attention due to its application value and prospects.In order to expand the serviceable range,people have investigated various superhydrophob...The research of superhydrophobic materials has attracted many researchers＇ attention due to its application value and prospects.In order to expand the serviceable range,people have investigated various superhydrophobic materials.The simple and easy preparation method has become the focus for superhydrophobic materials.In this paper,we present a program for preparing a rough surface on an aluminum foil,which possesses excellent hydrophobic properties after the treatment with low surface energy materials at high vacuum.The resulting contact angle is larger than 160° and the droplet cannot freeze on the surface above-10 ℃.Meanwhile,the modified aluminum foil with the thickness of less than 100 μm can be used as an ideal flexible applied material for superhydrophobicity/anti-icing.展开更多
Dear Editor,This letter proposes an unsupervised entity alignment method,which realizes integration of multiple multi-modal knowledge graphs adaptively.In recent years,Large-scale multi-modal knowledge graphs(LMKGs),c...Dear Editor,This letter proposes an unsupervised entity alignment method,which realizes integration of multiple multi-modal knowledge graphs adaptively.In recent years,Large-scale multi-modal knowledge graphs(LMKGs),containing text and image,have been widely applied in numerous knowledge-driven topics,such as question answering,entity linking,information extraction,reasoning and recommendation.展开更多
The advent of the big data era has provided many types of transportation datasets,such as metro smart card data,for studying residents’mobility and understanding how their mobility has been shaped and is shaping the ...The advent of the big data era has provided many types of transportation datasets,such as metro smart card data,for studying residents’mobility and understanding how their mobility has been shaped and is shaping the urban space.In this paper,we use metro smart card data from two Chinese metropolises,Shanghai and Shenzhen.Five metro mobility indicators are introduced,and association rules are established to explore the mobility patterns.The proportion of people entering and exiting the station is used to measure the jobs-housing balance.It is found that the average travel distance and duration of Shanghai passengers are higher than those of Shenzhen,and the proportion of metro commuters in Shanghai is higher than that of Shenzhen.The jobs-housing spatial relationship in Shenzhen based on metro travel is more balanced than that in Shanghai.The fundamental reason for the differences between the two cities is the difference in urban morphology.Compared with the monocentric structure of Shanghai,the polycentric structure of Shenzhen results in more scattered travel hotspots and more diverse travel routes,which helps Shenzhen to have a better jobs-housing balance.This paper fills a gap in comparative research among Chinese cities based on transportation big data analysis.The results provide support for planning metro routes,adjusting urban structure and land use to form a more reasonable metro network,and balancing the jobs-housing spatial relationship.展开更多
Understanding complex urban systems necessitates untangling the relationships between diverse urban elements such as population,infrastructure,and socioeconomic activities.Scaling laws are basic but effective rules fo...Understanding complex urban systems necessitates untangling the relationships between diverse urban elements such as population,infrastructure,and socioeconomic activities.Scaling laws are basic but effective rules for evaluating a city’s internal growth logic and assessing its efficiency by investigating whether urban indicators scale with population.To date,only limited research has empirically explored the scaling relations between variables of urban mobility in mega-cities at an intra-urban scale of a few meters.Using multiple urban-sensed and human-sensed data,this study proposes a thorough framework for quantifying the scaling laws in a city.To begin,urban mobility networks are built by aggregating population flows using large-scale mobile phone tracking data.To demonstrate the spatiotemporal variability of urban mobility,various network-based mobility measures are proposed.Following that,three different features of urban mobility laws are exposed,explaining spatial agglomeration,spatial hierarchical structures,and the temporal growth process.The scaling correlations between urban indicators pertaining to socioeconomic features and infrastructure and a mobility-population measure are then quantified using multi-sourced urban-sensed data.Applying this framework to the case study of Shenzhen,China revealed(a)spatial travel heterogeneity,hierarchical spatial structures,and mobility growth,and(b)not only a robust sub-linear relationship between infrastructure volume and population,but also a sub-linear relationship for socioeconomic activity.The identified scaling laws,both in terms of mobility measures and urban indicators,provide a multi-faceted portrait of the spatio-temporal variations of urban settings,allowing us to better understand intra-urban developments and,consequently,provide critical policy evaluations and suggestions for improving intra-urban efficiency in the future.展开更多
Increasing calls for zero-carbon cities invite transformative solutions for people and places within our cities around the world. Key to the transformation is cities and regions shifting in mobility away from fossil-f...Increasing calls for zero-carbon cities invite transformative solutions for people and places within our cities around the world. Key to the transformation is cities and regions shifting in mobility away from fossil-fuel based car-oriented solutions. The paper investigates a range of case studies where “tram-based boulevards” have been planned or implemented to provide such opportunities. The case studies share a common broader policy objective: to transform the car-oriented or car-saturated areas to an intensified urban template based on a critical presence of dedicated mid-tier transit infrastructure and active transport. “Trams”, or mid-tier, mid-capacity transit when combined with Transit oriented development (TOD) along whole corridors can provide transformative pathways towards zero-carbon outcomes as well as multiple, strong urban benefits. However, many successful or instructive examples of this practice from non-English speaking countries, particularly in Europe, are underdocumented in the international literature. The paper addresses this gap by investigating opportunities and challenges evident in a range of European case studies. These are explored for insight towards policy learning particularly in New World cities seeking to transform into a zero-carbon and more transit-oriented template: How can decision-makers avoid repeating the identified pitfalls, and instead focus on emulating the successful approaches and outcomes? We conclude the need for recognition of the inherent synergies between transport and land use settings in any endeavour, and their translation into policy priorities in both fields of planning. We also conclude the importance of decision makers proactively identifying and critically appraising specific opportunities for change, concerning funding, technology, public opinion, stakeholder alliances or market dynamics, and capitalising on them at suitable moments in time.展开更多
A clear diagram for the unfolding of protein induced by denaturant is a classical but still unsolved challenge. To explore the unfolded conformations of ubiquitin under different urea concentrations, we performed hybr...A clear diagram for the unfolding of protein induced by denaturant is a classical but still unsolved challenge. To explore the unfolded conformations of ubiquitin under different urea concentrations, we performed hybrid Monte Carlo-molecular dynamics simulations (MC-MD) guided by small angle X-ray scattering (SAXS) structural information. Conformational ensembles sampled by the hybrid MC-MD algorithm exhibited typical 3D structures at different urea concentrations. These typical structures suggested that ubiquitin was subjected to a sequential unfolding, where the native contacts between adjacent β-sheets at first were disrupted together with the exposure of hydrophobic core, followed by the conversion of remaining β-strands and helices into random coils. Ubiquitin in 8 mol·L?1 urea is almost a random coil. With the disruption of native structure, urea molecules are enriched at protein hydrated layer to stabilize newly exposed residues. Compared with water, urea molecules prefer to form hydrogen bonds with the backbone of ubiquitin, thus occupying nodes of the hydrogen bonding network that construct the secondary structure of proteins. Meanwhile, we also found that the slow dynamics of urea molecules was almost unchanged while the dynamics of water was accelerated in the hydration shell when more residues were unfolded and exposed. The former was also responsible for the stabilization of unfolded structures.展开更多
Nowadays,ensuring thequality of networkserviceshas become increasingly vital.Experts are turning toknowledge graph technology,with a significant emphasis on entity extraction in the identification of device configurat...Nowadays,ensuring thequality of networkserviceshas become increasingly vital.Experts are turning toknowledge graph technology,with a significant emphasis on entity extraction in the identification of device configurations.This research paper presents a novel entity extraction method that leverages a combination of active learning and attention mechanisms.Initially,an improved active learning approach is employed to select the most valuable unlabeled samples,which are subsequently submitted for expert labeling.This approach successfully addresses the problems of isolated points and sample redundancy within the network configuration sample set.Then the labeled samples are utilized to train the model for network configuration entity extraction.Furthermore,the multi-head self-attention of the transformer model is enhanced by introducing the Adaptive Weighting method based on the Laplace mixture distribution.This enhancement enables the transformer model to dynamically adapt its focus to words in various positions,displaying exceptional adaptability to abnormal data and further elevating the accuracy of the proposed model.Through comparisons with Random Sampling(RANDOM),Maximum Normalized Log-Probability(MNLP),Least Confidence(LC),Token Entrop(TE),and Entropy Query by Bagging(EQB),the proposed method,Entropy Query by Bagging and Maximum Influence Active Learning(EQBMIAL),achieves comparable performance with only 40% of the samples on both datasets,while other algorithms require 50% of the samples.Furthermore,the entity extraction algorithm with the Adaptive Weighted Multi-head Attention mechanism(AW-MHA)is compared with BILSTM-CRF,Mutil_Attention-Bilstm-Crf,Deep_Neural_Model_NER and BERT_Transformer,achieving precision rates of 75.98% and 98.32% on the two datasets,respectively.Statistical tests demonstrate the statistical significance and effectiveness of the proposed algorithms in this paper.展开更多
The use of freely-available multi-source imagery for mapping vegetation in montane terrain is important for many developing countries that do not have the funding for high-resolution data capture.Radar images are also...The use of freely-available multi-source imagery for mapping vegetation in montane terrain is important for many developing countries that do not have the funding for high-resolution data capture.Radar images are also now freely available and include Sentinel-1 in dual polarisation,and PALSAR-2.These images can penetrate cloud cover and provide the advantage of acquiring data in a cloudy tropical region.This research evaluated whether the addition of radar with optical and topographic data improves classification accuracy in a montane region in Sri Lanka.Six classification experiments were designed based on different combinations of image data to test whether radar data improved land cover classification accuracy compared with optical data alone.Random forest classifier in the Google Earth Engine has been utilised to classify the tropical montane vegetation.The results indicate that radar or optical data alone cannot obtain satisfactory results.However,when combining radar with optical data the overall accuracy increased by approximately 5%,and by an additional 2%when topography data were added.The highest accuracy(92%)was achieved with multiple imagery,and adding the vegetation indices improved the model slightly by 0.3%.In addition,feature importance analysis showed that radar data makes a significant contribution to the classification.These positive outcomes demonstrate that freely-accessible multi-source remotely-sensed data have impressive capability for vegetation mapping,and support the monitoring and managing of forest ecological resources in tropical montane regions.展开更多
The ubiquitous deployment and restricted consumption are the requirements restricting the development of Internet of Things.Thus,a promising technology named Internet of Lamps(Io L)is discussed in this paper to addres...The ubiquitous deployment and restricted consumption are the requirements restricting the development of Internet of Things.Thus,a promising technology named Internet of Lamps(Io L)is discussed in this paper to address these challenges.Compared with other communication networks,the remarkable advantage of Io L is that it can make full use of the existing lighting networks with sufficient power supply.The lamps can be connected to the Internet through wired power line communication and/or wireless communication,while the integration of integrated sensing,hybrid interconnection,and intelligent illumination is realized.In this paper,the Io L is discussed from three aspects including sensing layer,network layer,and application layer,realizing the comprehensive upgrade based on the conventional communication and illumination systems.Meanwhile,several novel technologies of Io L are discussed based on the requirements of sensing,communication,and control,which have put forward practical solutions to the issues faced by Io L.Moreover,the challenges and opportunities for Io L are highlighted from various parts of the system structure,so as to provide future insights and potential trends for researchers in this field.展开更多
The reliable application of field deployable fluorescent dissolved organic matter(fDOM)probes is hindered by several influencing factors which need to be compensated.This manuscript describes the corrections of temper...The reliable application of field deployable fluorescent dissolved organic matter(fDOM)probes is hindered by several influencing factors which need to be compensated.This manuscript describes the corrections of temperature,pH,turbidity and inner filter effect on fluorescence signal of a commercial fDOM probe(fDOMs).For this,Australian waters with wide ranging qualities were selected,e.g.dissolved organic carbon(DOC)ranging from∼1 to∼30 mg/L,specific UV absorbance at 254 nm from∼1 to∼6 L/m/mg and turbidity from∼1 to∼350 FNU.Laboratory-based model calibration experiments(MCEs)were performed.A model template was developed and used for the development of the correction models.For each factor,data generated through MCEs were used to determine model coefficient(α)values by fitting the generated model to the experimental data.Four discrete factor models were generated by determination of a factor-specificαvalue.Theαvalues derived for each water of the MCEs subset were consistent for each factor model.This indicated generic nature of the fourαvalues across wide-ranging water qualities.High correlation between fDOMs and DOC were achieved after applying the four-factor compensation models to new data(r,0.96,p<0.05).Also,average biases(and%)between DOC predicted through fDOMs and actual DOC were decreased by applying the four-factor compensationmodel(from3.54(60.9%)to 1.28(16.7%)mg/L DOC).These correction models were incorporated into a Mi-crosoft EXCEL-based software termed EXOf-Correct for ready-to-use applications.展开更多
Hydrogen spillover mechanism of metal-supported covalent-organic frameworks COF-105 is investigated by means of the density functional theory, and the effects of metal catalysts M_4（Pt_4, Pd_4, and Ni_4） on the whol...Hydrogen spillover mechanism of metal-supported covalent-organic frameworks COF-105 is investigated by means of the density functional theory, and the effects of metal catalysts M_4（Pt_4, Pd_4, and Ni_4） on the whole spillover process are systematically analyzed. These three metal catalysts exhibit several similar phenomena：（i） they prefer to deposit on the tetra（_4-dihydroxyborylphenyl） silane（TBPS） cluster with surface-contacted configuration;（ii） only the H atoms at the bridge site can migrate to 2,3,6,7,10,11-hexahydroxy triphenylene（HHTP） and TBPS surfaces, and the migration process is an endothermic reaction and not stable;（iii） the introduction of M_4 catalyst can greatly reduce the diffusion energy barrier of H atoms, which makes it easier for the H atoms to diffuse on the substrate surface. Differently, all of the H2 molecules spontaneously dissociate into H atoms onto Pt_4 and Pd_4clusters. However, the adsorbed H2 molecules on Ni_4 cluster show two types of adsorption states： one activated state with stretched H–H bond length of 0.88 ？A via the Kubas interaction and five dissociated states with separated hydrogen atoms. Among all the M_4 catalysts, the orders of the binding energy of M_4 deposited on the substrate and average chemisorption energy per H2 molecule are Pt_4〉Ni_4〉Pd_4. On the contrary, the orders of the migration and diffusion barriers of H atoms are Pt_4展开更多
Our infrastructure investment decisions matter enormously if infrastructure is to be long lived, so how can we select infrastructure investments that are optimum？ How do we determine what would be the best investment...Our infrastructure investment decisions matter enormously if infrastructure is to be long lived, so how can we select infrastructure investments that are optimum？ How do we determine what would be the best investments to make.展开更多
Under the background of a new round of transformation and upgrading of the marine fishery industrial structure and the"speed up and upgrading"of the national marine ranching,this paper uses the method of com...Under the background of a new round of transformation and upgrading of the marine fishery industrial structure and the"speed up and upgrading"of the national marine ranching,this paper uses the method of combining practical experience,literature review,and field research to describe the development of marine ranching at home and abroad,and summarizes the practice process and achievements of Tianjin marine ranch:one national and two provincial marine ranch demonstration areas,16 ecotype reef areas,one seafood demonstration area,and one floating fish reef demonstration area were built,with a total scale of 26.9 km^(2),and a total of 134900 m^(2) fish reefs.This paper emphatically analyzed the construction experience and characteristics of the Tianjin Dashentang Marine Ranch demonstration area.Combined with the development orientation and objectives of Tianjin marine ranch,it is proposed to unify understanding,perfect development concept,accelerate the pace of scientific research,and adhere to ecological priority.In future,the construction of Tianjin marine ranch should encourage innovation to achieve leap-forward development,explore a new model of fishery development based on the'Economic Union',with'marine ranching-ecological farming-leisure tourism-featured products'as the main body.Based on relevant experience at home and abroad,the industrialization model of marine ranch with Tianjin characteristics should be established,which aims to provide strong support for the construction of"blue granary"in Tianjin,the implementation of Tianjin's coastal ranching strategy,and the promotion of Tianjin coastal ecosystem reconstruction and fishery resource recovery.展开更多
Achieving the 17 United Nations sustainable development goals(SDGs)in China largely depends on the transition of cities toward sustainable development.However,significant knowledge gaps exist in evaluating the SDG ind...Achieving the 17 United Nations sustainable development goals(SDGs)in China largely depends on the transition of cities toward sustainable development.However,significant knowledge gaps exist in evaluating the SDG index at the city scale and in understanding how to simulate pathways to achieve the 17 SDGs for Chinese cities by 2030.This study aimed to quantify the SDG index of 285 Chinese cities and developed a forecasting model to simulate the performance of each SDG in each city until 2030 using varied scenarios.The results indicated that although the SDG index in Chinese cities increased by 33.97%during 2005–2016,Chinese cities,which continued their past paths,achieved an average of only five SDGs by 2030.To promote the joint achievement of all SDGs,we designed different paths for all SDGs of each of the 285 cities and simulated their SDG index until 2030.Under the scenarios,216 Chinese cities(75.79%)could achieve 9–13 more SDGs in 2030 and the overall SDG index can improve from 74.57 in 2030 to 97.49(target score 100)by adopting more intensive path adjustment.We lastly determined a cost-effective path for each SDG of each city to promote joint achievement of all SDGs by 2030.The proposed simulation model and cost-effective path serve as a foundation for other countries to simulate SDG progress and develop pathways for achieving SDGs in the future.展开更多
Inventing Future Cities Author:Michael Batty Year:2018 Publisher:The MIT Press ISBN:9780262038959(304 pages,in English)Introduction:reflections on the future of cities Cities,as great products of human inventions and ...Inventing Future Cities Author:Michael Batty Year:2018 Publisher:The MIT Press ISBN:9780262038959(304 pages,in English)Introduction:reflections on the future of cities Cities,as great products of human inventions and creations,have undoubtedly become the main habitat for the vast majority of the world's population through the urbanization process of the past 100 years,following the Industrial Revolution.展开更多
Legacy asbestos in built-up urban areas poses a risk of exposure to the surrounding community through environmental exposure pathways.Better understanding the exposure risk of in-situ asbestos containing materials(ACM...Legacy asbestos in built-up urban areas poses a risk of exposure to the surrounding community through environmental exposure pathways.Better understanding the exposure risk of in-situ asbestos containing materials(ACM)presents to surrounding communities through these pathways can better inform its management and reduce asbestos-related diseases.Remote sensing imagery and computer vision techniques facilitate the automated detection of ACM roofs across urban areas.Identifying ACM roofs coupled with GIS-based approaches to evaluate urban community characteristics provides an assessment of community exposure risk to asbestos in a scenario where ACM roofs are disturbed or degraded.This study develops a novel Asbestos-Community Exposure Risk Assessment(A-CERA)framework and associated method and then applies it to a case study urban area located in Australia.A-CERA was developed and applied using a three-phase study method.Phase 1 develops a framework of asbestos exposure risk from literature and subject matter expert focus groups.Phase two formulates the techniques and methods underpinning A-CERA,including autonomous computer vision ACM roof detection,GIS-based land-use feature extraction,and community exposure risk quantification and assessment.Phase 3 applies the developed A-CERA framework to an urban area covering 320 square kilometres with 2,512 detected industrial ACM roofs.Each ACM roof was ranked from the highest assessed level of community exposure risk to the lowest.A-CERA advances the way ACM materials are managed within the urban footprint to reduce asbestos-related diseases.展开更多
基金Wuhan University State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing,No.21S02。
文摘With the rise of smart phones,mobile applications have been widely used in daily life.However,the relationship between individuals’mobile application usage and cities’economic development has yet to be investigated.To study this question,this work utilizes a dataset containing users’history of mobile application usage records(MAURs)and investigates how MAURs are related to Chinese cities’economic development.Our analysis shows the cities’GDP and number of MAURs are highly correlated,and at the individual level,people in wealthier cities(higher GDP per capita)tend to have more active mobile application usage(MAURs per capita).The results also demonstrate the relevance between cities’GDP and MAURs varies significantly among different demographic groups,with male users’relevance consistently higher than female users’and working-age people’s relevance higher than other age groups.A boosted tree regression model is then applied to predict cities’GDP with MAURs and proves to achieve high goodness-of-fit(over 0.8 R-square)and good prediction accuracy,especially for the economically developed and populous regions in China.To the best of our knowledge,this is the first time that the relationship between MAURs and cities’economic development is revealed,which contributes to novel knowledge discovery for regionalization and urban development.
基金supported by the National Nature Science Foundation of China (Nos.21547011,21307036,51708356)the Natural Science Foundation of Guangdong Province (No.2014A030313761)the Science and Technology Research Project of Shenzhen (Nos.ZDSYS201606061530079,JCYJ20150324141711622,JCYJ20150529164656097)
文摘Electrolysis is a promising technology to improve sludge dewaterability efficiently with negligible environmental impact. To intensify the electrolytic efficiency, the effect of electrolytes(NaCl, Na_2SO_4, NaNO_3, and NaClO_4) on electrolysis pretreatment of municipal sludge and its mechanisms was investigated using Ti/PbO_2 electrodes. The electrolytes,which enhanced the production of oxidative radicals, showed a significant synergetic effect in reducing the capillary suction time(CST) of sludge. NaCl was distinguished from the other electrolytes since it formed a large amount of active chlorine species, which oxidized the sludge cells to improve the sludge dewaterability. The surface morphologies as well as the soluble proteins and polysaccharides were analyzed to unravel the underlying mechanisms of sludge dewaterability. Additionally, an economic assessment showed that NaCl addition in the electrolysis pretreatment can be a suitable technique for enhancing municipal sludge dewaterability.
文摘The effect of soil stratification was studied through numerical investigation based on the coupled model of solute transport in deformable unsaturated soil. The theoretical model implied two-way coupled excess pore pressure and soil deformation based on Biot's consolidation theory as well as a one-way coupled volatile pollutant concentration field developed from the advection-diffusion theory. Embedded in the model, the degree of saturation, fluid compressibility, self-weight of the soil matrix, porosity variance, longitudinal dispersion, and linear sorption were computed. Based on simulation results of a proposed three-layer landfill model using the finite element method, the multi-layer effects are discussed with regard to the hydraulic conductivity, shear modulus, degree of saturation, molecular diffusion coefficient, and thickness of each layer. Generally speaking, contaminants spread faster in a stratified field with a soft and highly permeable top layer; soil parameters of the top layer are more critical than the lower layers but controlling soil thicknesses will alter the results. This numerical investigation showed noticeable impacts of stratified soil properties on solute migration results, demonstrating the importance of correctly modeling layered soil instead of simply assuming the averaged properties across the soil profile.
文摘Taking Poyang Lake Eco-economic Zone as an example,we analyzed existing problems in China'forest resource protection from the perspective of legal system.The problems include unclear property right system of forest resource,imperfect compensation mechanism for forest ecology,forest cutting quota scheme not resolutely put into practice,legal supervision of forest protection not implemented,and lack of integration in forest protection laws.Based on these problems,we put forward countermeasures and suggestions:establish clear forest resource property system;improve ecological benefit compensation mechanism in legal form;strictly implement forest cutting quota scheme;strengthen legal supervision of forest protection;and keep legal system integral for forest resource protection.
基金Project supported by China Postdoctoral Science Foundation(Grant No.2016M590137)the National Natural Science Foundation of China(Grant No.21476246)+2 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2016047)the KIST Institutional Program(Grant No.2E26291)Research Grants of NRF funded by the National Research Foundation under the Ministry of Science,ICT & Future,Korea(Grant No.NRF-2015H1D3A1036078)
文摘The research of superhydrophobic materials has attracted many researchers＇ attention due to its application value and prospects.In order to expand the serviceable range,people have investigated various superhydrophobic materials.The simple and easy preparation method has become the focus for superhydrophobic materials.In this paper,we present a program for preparing a rough surface on an aluminum foil,which possesses excellent hydrophobic properties after the treatment with low surface energy materials at high vacuum.The resulting contact angle is larger than 160° and the droplet cannot freeze on the surface above-10 ℃.Meanwhile,the modified aluminum foil with the thickness of less than 100 μm can be used as an ideal flexible applied material for superhydrophobicity/anti-icing.
基金supported by the National Key Research and Development Project(2019YFB2102500)the National Nature Science Foundations of China(U20B2052)。
文摘Dear Editor,This letter proposes an unsupervised entity alignment method,which realizes integration of multiple multi-modal knowledge graphs adaptively.In recent years,Large-scale multi-modal knowledge graphs(LMKGs),containing text and image,have been widely applied in numerous knowledge-driven topics,such as question answering,entity linking,information extraction,reasoning and recommendation.
基金National Key R&D Program of China(No.2019YFB2103102)Hong Kong Polytechnic University(No.CD06,P0042540)。
文摘The advent of the big data era has provided many types of transportation datasets,such as metro smart card data,for studying residents’mobility and understanding how their mobility has been shaped and is shaping the urban space.In this paper,we use metro smart card data from two Chinese metropolises,Shanghai and Shenzhen.Five metro mobility indicators are introduced,and association rules are established to explore the mobility patterns.The proportion of people entering and exiting the station is used to measure the jobs-housing balance.It is found that the average travel distance and duration of Shanghai passengers are higher than those of Shenzhen,and the proportion of metro commuters in Shanghai is higher than that of Shenzhen.The jobs-housing spatial relationship in Shenzhen based on metro travel is more balanced than that in Shanghai.The fundamental reason for the differences between the two cities is the difference in urban morphology.Compared with the monocentric structure of Shanghai,the polycentric structure of Shenzhen results in more scattered travel hotspots and more diverse travel routes,which helps Shenzhen to have a better jobs-housing balance.This paper fills a gap in comparative research among Chinese cities based on transportation big data analysis.The results provide support for planning metro routes,adjusting urban structure and land use to form a more reasonable metro network,and balancing the jobs-housing spatial relationship.
基金supported by the National Natural Science Foundation of China[grant numbers 42001393,42071360,71961137003 and 42101472]the Basic Research Program of Shenzhen Science and Technology Innovation Committee[grant number JCYJ20220530152817039]+1 种基金the Natural Science Foundation of Guangdong Province[grant number 2019A1515011049]the Key Laboratory of National Geographic Census and Monitoring,MNR[grant number 2020NGCMZD02].
文摘Understanding complex urban systems necessitates untangling the relationships between diverse urban elements such as population,infrastructure,and socioeconomic activities.Scaling laws are basic but effective rules for evaluating a city’s internal growth logic and assessing its efficiency by investigating whether urban indicators scale with population.To date,only limited research has empirically explored the scaling relations between variables of urban mobility in mega-cities at an intra-urban scale of a few meters.Using multiple urban-sensed and human-sensed data,this study proposes a thorough framework for quantifying the scaling laws in a city.To begin,urban mobility networks are built by aggregating population flows using large-scale mobile phone tracking data.To demonstrate the spatiotemporal variability of urban mobility,various network-based mobility measures are proposed.Following that,three different features of urban mobility laws are exposed,explaining spatial agglomeration,spatial hierarchical structures,and the temporal growth process.The scaling correlations between urban indicators pertaining to socioeconomic features and infrastructure and a mobility-population measure are then quantified using multi-sourced urban-sensed data.Applying this framework to the case study of Shenzhen,China revealed(a)spatial travel heterogeneity,hierarchical spatial structures,and mobility growth,and(b)not only a robust sub-linear relationship between infrastructure volume and population,but also a sub-linear relationship for socioeconomic activity.The identified scaling laws,both in terms of mobility measures and urban indicators,provide a multi-faceted portrait of the spatio-temporal variations of urban settings,allowing us to better understand intra-urban developments and,consequently,provide critical policy evaluations and suggestions for improving intra-urban efficiency in the future.
文摘Increasing calls for zero-carbon cities invite transformative solutions for people and places within our cities around the world. Key to the transformation is cities and regions shifting in mobility away from fossil-fuel based car-oriented solutions. The paper investigates a range of case studies where “tram-based boulevards” have been planned or implemented to provide such opportunities. The case studies share a common broader policy objective: to transform the car-oriented or car-saturated areas to an intensified urban template based on a critical presence of dedicated mid-tier transit infrastructure and active transport. “Trams”, or mid-tier, mid-capacity transit when combined with Transit oriented development (TOD) along whole corridors can provide transformative pathways towards zero-carbon outcomes as well as multiple, strong urban benefits. However, many successful or instructive examples of this practice from non-English speaking countries, particularly in Europe, are underdocumented in the international literature. The paper addresses this gap by investigating opportunities and challenges evident in a range of European case studies. These are explored for insight towards policy learning particularly in New World cities seeking to transform into a zero-carbon and more transit-oriented template: How can decision-makers avoid repeating the identified pitfalls, and instead focus on emulating the successful approaches and outcomes? We conclude the need for recognition of the inherent synergies between transport and land use settings in any endeavour, and their translation into policy priorities in both fields of planning. We also conclude the importance of decision makers proactively identifying and critically appraising specific opportunities for change, concerning funding, technology, public opinion, stakeholder alliances or market dynamics, and capitalising on them at suitable moments in time.
基金financially supported by the National Natural Science Foundation of China (Nos. 21504092 and U1832177)One Hundred Person Project of the Chinese Academy of Sciences+1 种基金Computing Center of Jilin ProvinceHenan Province Supercomputer Center for essential support
文摘A clear diagram for the unfolding of protein induced by denaturant is a classical but still unsolved challenge. To explore the unfolded conformations of ubiquitin under different urea concentrations, we performed hybrid Monte Carlo-molecular dynamics simulations (MC-MD) guided by small angle X-ray scattering (SAXS) structural information. Conformational ensembles sampled by the hybrid MC-MD algorithm exhibited typical 3D structures at different urea concentrations. These typical structures suggested that ubiquitin was subjected to a sequential unfolding, where the native contacts between adjacent β-sheets at first were disrupted together with the exposure of hydrophobic core, followed by the conversion of remaining β-strands and helices into random coils. Ubiquitin in 8 mol·L?1 urea is almost a random coil. With the disruption of native structure, urea molecules are enriched at protein hydrated layer to stabilize newly exposed residues. Compared with water, urea molecules prefer to form hydrogen bonds with the backbone of ubiquitin, thus occupying nodes of the hydrogen bonding network that construct the secondary structure of proteins. Meanwhile, we also found that the slow dynamics of urea molecules was almost unchanged while the dynamics of water was accelerated in the hydration shell when more residues were unfolded and exposed. The former was also responsible for the stabilization of unfolded structures.
基金supported by the National Key R&D Program of China(2019YFB2103202).
文摘Nowadays,ensuring thequality of networkserviceshas become increasingly vital.Experts are turning toknowledge graph technology,with a significant emphasis on entity extraction in the identification of device configurations.This research paper presents a novel entity extraction method that leverages a combination of active learning and attention mechanisms.Initially,an improved active learning approach is employed to select the most valuable unlabeled samples,which are subsequently submitted for expert labeling.This approach successfully addresses the problems of isolated points and sample redundancy within the network configuration sample set.Then the labeled samples are utilized to train the model for network configuration entity extraction.Furthermore,the multi-head self-attention of the transformer model is enhanced by introducing the Adaptive Weighting method based on the Laplace mixture distribution.This enhancement enables the transformer model to dynamically adapt its focus to words in various positions,displaying exceptional adaptability to abnormal data and further elevating the accuracy of the proposed model.Through comparisons with Random Sampling(RANDOM),Maximum Normalized Log-Probability(MNLP),Least Confidence(LC),Token Entrop(TE),and Entropy Query by Bagging(EQB),the proposed method,Entropy Query by Bagging and Maximum Influence Active Learning(EQBMIAL),achieves comparable performance with only 40% of the samples on both datasets,while other algorithms require 50% of the samples.Furthermore,the entity extraction algorithm with the Adaptive Weighted Multi-head Attention mechanism(AW-MHA)is compared with BILSTM-CRF,Mutil_Attention-Bilstm-Crf,Deep_Neural_Model_NER and BERT_Transformer,achieving precision rates of 75.98% and 98.32% on the two datasets,respectively.Statistical tests demonstrate the statistical significance and effectiveness of the proposed algorithms in this paper.
文摘The use of freely-available multi-source imagery for mapping vegetation in montane terrain is important for many developing countries that do not have the funding for high-resolution data capture.Radar images are also now freely available and include Sentinel-1 in dual polarisation,and PALSAR-2.These images can penetrate cloud cover and provide the advantage of acquiring data in a cloudy tropical region.This research evaluated whether the addition of radar with optical and topographic data improves classification accuracy in a montane region in Sri Lanka.Six classification experiments were designed based on different combinations of image data to test whether radar data improved land cover classification accuracy compared with optical data alone.Random forest classifier in the Google Earth Engine has been utilised to classify the tropical montane vegetation.The results indicate that radar or optical data alone cannot obtain satisfactory results.However,when combining radar with optical data the overall accuracy increased by approximately 5%,and by an additional 2%when topography data were added.The highest accuracy(92%)was achieved with multiple imagery,and adding the vegetation indices improved the model slightly by 0.3%.In addition,feature importance analysis showed that radar data makes a significant contribution to the classification.These positive outcomes demonstrate that freely-accessible multi-source remotely-sensed data have impressive capability for vegetation mapping,and support the monitoring and managing of forest ecological resources in tropical montane regions.
基金supported by Tsinghua University-China Mobile Research Institute Joint Innovation Centerin part by the Science,Technology and Innovation Commission of Shenzhen Municipality(No.JSGG20201103095805015)+2 种基金in part by the National Natural Science Foundation of China(No.61871255)in part by the Fok Ying-Tung Education Foundationin part by Beijing National Research Center for Information Science and Technology(No.BNR2022RC01017)。
文摘The ubiquitous deployment and restricted consumption are the requirements restricting the development of Internet of Things.Thus,a promising technology named Internet of Lamps(Io L)is discussed in this paper to address these challenges.Compared with other communication networks,the remarkable advantage of Io L is that it can make full use of the existing lighting networks with sufficient power supply.The lamps can be connected to the Internet through wired power line communication and/or wireless communication,while the integration of integrated sensing,hybrid interconnection,and intelligent illumination is realized.In this paper,the Io L is discussed from three aspects including sensing layer,network layer,and application layer,realizing the comprehensive upgrade based on the conventional communication and illumination systems.Meanwhile,several novel technologies of Io L are discussed based on the requirements of sensing,communication,and control,which have put forward practical solutions to the issues faced by Io L.Moreover,the challenges and opportunities for Io L are highlighted from various parts of the system structure,so as to provide future insights and potential trends for researchers in this field.
基金an Australian Research Council Linkage Project,grant number LP160100217.
文摘The reliable application of field deployable fluorescent dissolved organic matter(fDOM)probes is hindered by several influencing factors which need to be compensated.This manuscript describes the corrections of temperature,pH,turbidity and inner filter effect on fluorescence signal of a commercial fDOM probe(fDOMs).For this,Australian waters with wide ranging qualities were selected,e.g.dissolved organic carbon(DOC)ranging from∼1 to∼30 mg/L,specific UV absorbance at 254 nm from∼1 to∼6 L/m/mg and turbidity from∼1 to∼350 FNU.Laboratory-based model calibration experiments(MCEs)were performed.A model template was developed and used for the development of the correction models.For each factor,data generated through MCEs were used to determine model coefficient(α)values by fitting the generated model to the experimental data.Four discrete factor models were generated by determination of a factor-specificαvalue.Theαvalues derived for each water of the MCEs subset were consistent for each factor model.This indicated generic nature of the fourαvalues across wide-ranging water qualities.High correlation between fDOMs and DOC were achieved after applying the four-factor compensation models to new data(r,0.96,p<0.05).Also,average biases(and%)between DOC predicted through fDOMs and actual DOC were decreased by applying the four-factor compensationmodel(from3.54(60.9%)to 1.28(16.7%)mg/L DOC).These correction models were incorporated into a Mi-crosoft EXCEL-based software termed EXOf-Correct for ready-to-use applications.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304079,11304140,11404094,and 11504088)the China National Scholarship Foundation(Grant No.201508410255)+4 种基金the Foundation for Young Core Teachers of Higher Education Institutions of Henan Province of Chinathe Foundation for Young Core Teachers of Henan University of Technology in Chinathe Korea Institute of Science and Technology(KIST)Institutional Program(Grant No.2E26291)Flag Program(Grant No.2E26300)the Research Grants of NRF funded by the National Research Foundation under the Ministry of Science,ICT&Future,Korea(Grant No.NRF-2015H1D3A1036078)
文摘Hydrogen spillover mechanism of metal-supported covalent-organic frameworks COF-105 is investigated by means of the density functional theory, and the effects of metal catalysts M_4（Pt_4, Pd_4, and Ni_4） on the whole spillover process are systematically analyzed. These three metal catalysts exhibit several similar phenomena：（i） they prefer to deposit on the tetra（_4-dihydroxyborylphenyl） silane（TBPS） cluster with surface-contacted configuration;（ii） only the H atoms at the bridge site can migrate to 2,3,6,7,10,11-hexahydroxy triphenylene（HHTP） and TBPS surfaces, and the migration process is an endothermic reaction and not stable;（iii） the introduction of M_4 catalyst can greatly reduce the diffusion energy barrier of H atoms, which makes it easier for the H atoms to diffuse on the substrate surface. Differently, all of the H2 molecules spontaneously dissociate into H atoms onto Pt_4 and Pd_4clusters. However, the adsorbed H2 molecules on Ni_4 cluster show two types of adsorption states： one activated state with stretched H–H bond length of 0.88 ？A via the Kubas interaction and five dissociated states with separated hydrogen atoms. Among all the M_4 catalysts, the orders of the binding energy of M_4 deposited on the substrate and average chemisorption energy per H2 molecule are Pt_4〉Ni_4〉Pd_4. On the contrary, the orders of the migration and diffusion barriers of H atoms are Pt_4
文摘Our infrastructure investment decisions matter enormously if infrastructure is to be long lived, so how can we select infrastructure investments that are optimum？ How do we determine what would be the best investments to make.
基金supported by the National Key R&D Plan(2019YFE0122300)Tianjin City Science and Technology Major Special Project and Project(18ZXRHSF00270)+1 种基金Tianjin Agricultural Development Service Center youth science and technology innovation project(ZXKJ202429)Tianjin City Mariculture Modern Agricultural Industry Technology System Innovation Team Project(ITTMRS2023005).
文摘Under the background of a new round of transformation and upgrading of the marine fishery industrial structure and the"speed up and upgrading"of the national marine ranching,this paper uses the method of combining practical experience,literature review,and field research to describe the development of marine ranching at home and abroad,and summarizes the practice process and achievements of Tianjin marine ranch:one national and two provincial marine ranch demonstration areas,16 ecotype reef areas,one seafood demonstration area,and one floating fish reef demonstration area were built,with a total scale of 26.9 km^(2),and a total of 134900 m^(2) fish reefs.This paper emphatically analyzed the construction experience and characteristics of the Tianjin Dashentang Marine Ranch demonstration area.Combined with the development orientation and objectives of Tianjin marine ranch,it is proposed to unify understanding,perfect development concept,accelerate the pace of scientific research,and adhere to ecological priority.In future,the construction of Tianjin marine ranch should encourage innovation to achieve leap-forward development,explore a new model of fishery development based on the'Economic Union',with'marine ranching-ecological farming-leisure tourism-featured products'as the main body.Based on relevant experience at home and abroad,the industrialization model of marine ranch with Tianjin characteristics should be established,which aims to provide strong support for the construction of"blue granary"in Tianjin,the implementation of Tianjin's coastal ranching strategy,and the promotion of Tianjin coastal ecosystem reconstruction and fishery resource recovery.
基金support of the project through a PhD studentship(project account code:RK2K)。
文摘Achieving the 17 United Nations sustainable development goals(SDGs)in China largely depends on the transition of cities toward sustainable development.However,significant knowledge gaps exist in evaluating the SDG index at the city scale and in understanding how to simulate pathways to achieve the 17 SDGs for Chinese cities by 2030.This study aimed to quantify the SDG index of 285 Chinese cities and developed a forecasting model to simulate the performance of each SDG in each city until 2030 using varied scenarios.The results indicated that although the SDG index in Chinese cities increased by 33.97%during 2005–2016,Chinese cities,which continued their past paths,achieved an average of only five SDGs by 2030.To promote the joint achievement of all SDGs,we designed different paths for all SDGs of each of the 285 cities and simulated their SDG index until 2030.Under the scenarios,216 Chinese cities(75.79%)could achieve 9–13 more SDGs in 2030 and the overall SDG index can improve from 74.57 in 2030 to 97.49(target score 100)by adopting more intensive path adjustment.We lastly determined a cost-effective path for each SDG of each city to promote joint achievement of all SDGs by 2030.The proposed simulation model and cost-effective path serve as a foundation for other countries to simulate SDG progress and develop pathways for achieving SDGs in the future.
文摘Inventing Future Cities Author:Michael Batty Year:2018 Publisher:The MIT Press ISBN:9780262038959(304 pages,in English)Introduction:reflections on the future of cities Cities,as great products of human inventions and creations,have undoubtedly become the main habitat for the vast majority of the world's population through the urbanization process of the past 100 years,following the Industrial Revolution.
文摘Legacy asbestos in built-up urban areas poses a risk of exposure to the surrounding community through environmental exposure pathways.Better understanding the exposure risk of in-situ asbestos containing materials(ACM)presents to surrounding communities through these pathways can better inform its management and reduce asbestos-related diseases.Remote sensing imagery and computer vision techniques facilitate the automated detection of ACM roofs across urban areas.Identifying ACM roofs coupled with GIS-based approaches to evaluate urban community characteristics provides an assessment of community exposure risk to asbestos in a scenario where ACM roofs are disturbed or degraded.This study develops a novel Asbestos-Community Exposure Risk Assessment(A-CERA)framework and associated method and then applies it to a case study urban area located in Australia.A-CERA was developed and applied using a three-phase study method.Phase 1 develops a framework of asbestos exposure risk from literature and subject matter expert focus groups.Phase two formulates the techniques and methods underpinning A-CERA,including autonomous computer vision ACM roof detection,GIS-based land-use feature extraction,and community exposure risk quantification and assessment.Phase 3 applies the developed A-CERA framework to an urban area covering 320 square kilometres with 2,512 detected industrial ACM roofs.Each ACM roof was ranked from the highest assessed level of community exposure risk to the lowest.A-CERA advances the way ACM materials are managed within the urban footprint to reduce asbestos-related diseases.
