Climate crises necessitate adaptive,cost-effective,and community-driven strategies to enhance urban resilience.Tactical urban design,which includes temporary and experimental interventions,is becoming increasingly vit...Climate crises necessitate adaptive,cost-effective,and community-driven strategies to enhance urban resilience.Tactical urban design,which includes temporary and experimental interventions,is becoming increasingly vital,particularly in indigenous contexts.This study explores the spatial agency approach within tactical urbanism,emphasizing low-technology techniques,indigenous knowledge,and decentralized design as active elements in transforming public spaces.It aims to review recent trends and alternative tactical strategies in indigenous settings while identifying the attributes and mechanisms that contribute to the creation of sustainable public spaces through spatial agency.Employing an interpretive qualitative methodology that includes case studies and content analysis,the research focuses on the Open-Air Lab in Dakar,Senegal(Codesign Lab,Paolo Cascone).This project,a small-scale public infrastructure initiative born from participatory design,exemplifies a hybrid model that combines traditional craftsmanship,low-tech digital fabrication,and environmentally conscious solutions.The findings indicate that framing spatial agency as an actor-network process brings marginalized actors and practices to the forefront,fostering empowerment,social synergy,and climate-responsive design.The study advocates for a shift in tactical urban design from ephemeral placemaking toward long-term,adaptive strategies grounded in local materiality,community engagement,knowledge systems,and decentralized networks.These insights reshape the understanding of urban adaptability and provide practical guidance for architects and planners aiming to create inclusive,climate-resilient public spaces in indigenous and Global South contexts.展开更多
Language plays a significant role in business,trade and commerce.Bargaining in open-air markets often involves the speech act of negotiating,compromising and manoeuvring,which could either result in conflict or persua...Language plays a significant role in business,trade and commerce.Bargaining in open-air markets often involves the speech act of negotiating,compromising and manoeuvring,which could either result in conflict or persuasion of the potential buyer to patronize a seller.This article examined the sociolinguistic aspects of language use between sellers and buyers in Ipata,a popular market in Ilorin,north-central Nigeria.The call strategy,spiel,honorification,pragmatic mechanics as well as sociolinguistic style employed by vendors were observed.The objectives of the study were to:identify the number of languages used in Ipata market;investigate the factors that influence the choice of any of the languages used between sellers and buyers at a particular time;analyze their sociolinguistic and stylistic features;and discuss some of the barriers that could cause intercultural communication breakdown between sellers and buyers in a market situation.Oral interview,systematic observation and Bauman’s(2001)method of street recording were used to gather data for the study.Sixty-five people comprising thirty-six females and twenty-nine males were interviewed.The survey which spanned three months discovered that open-air markets bear some universal features,however,due to cultural relativity,variations occur.To this end,it was established that Ipata market harbours different languages;it also identified calls and spiels with their characteristic stylistic,sociolinguistic and discourse features in the market.In conclusion,the study argued that studying the verbal discourse of marketplaces is significant as it defines what the language-culture-society-relationship is all about.展开更多
The framing of this theme would contribute to a better analysis of the benefits of open-air quarrying in Zinder, and should make it possible to understand and measure the socio-environmental externalities of this type...The framing of this theme would contribute to a better analysis of the benefits of open-air quarrying in Zinder, and should make it possible to understand and measure the socio-environmental externalities of this type of activity in an urban environment. The approach method consisted of carrying out surveys combined with field observations and interviews with the various stakeholders as well as the local population. The results obtained made it possible to identify both positive and negative impacts. The positive impacts are above all the advantages derived from these aggregate quarries, in particular, the creation of direct and permanent jobs and the increase in community income. The price of piling up a truck costs around 28,000 CFA ($56 CAN) and that of loading is around 10,000 F CFA ($20 CAN). This has the effect of removing young people (20 - 39 years old) from the circuit of migration outside the region and even the country. The possibility of using the extraction sites by the local population was identified, in terms of profits relating to fish farming, off-season crops, animal drinking and reclaimed plots. The study also noted negative externalities, such as the temptation of young boys to become involved in extractive activities for immediate gains at the expense of school attendance. Added to this is the upheaval in the topography of the urban landscape, pollution and nuisances (noise, visual and olfactory), while the disappearance or clogging of quarry ponds is the cause of frequent flooding in the neighborhoods. In short, corrective measures (e.g. the revegetation of sites) certainly make it possible to minimize the harmful impacts on the urban environment. But, to improve the performance and organizational capacity of the quarrying industry in Niger, even stronger regulation, training and awareness of stakeholders prove to be the necessary measures.展开更多
Fabricating organic solar cells(OSCs)in open-air and room-temperature environments is essential for cost-effective roll-to-roll printing,but its performance is limited by non-ideal block and surface morphology of acti...Fabricating organic solar cells(OSCs)in open-air and room-temperature environments is essential for cost-effective roll-to-roll printing,but its performance is limited by non-ideal block and surface morphology of active layer.Herein,we demonstrate a record power conversion efficiency(PCE)of 19.72%in open-air and as-cast processed devices by using a lowcost terpolymer donor(PTQ20-5)to optimize the block and surface morphology.Compared with the counterpart PTQ10,PTQ20-5 shows increased hydrophobicity,which can better prevent the intrusion of H_(2)O molecules in the film formation process in open-air environment,giving excellent humidity tolerance of corresponding devices.Moreover,the enhanced dielectric constant results in reduced exciton binding energy and improved charge transport of PTQ20-5,leading to improved charge separation and transfer,and suppressed carrier recombination in the devices.Besides,the PTQ20-5-based film has more appropriate block morphological features of balanced molecular self-assembly and phase separation,which simultaneously promotes the charge carrier transport and inhibits the carrier recombination at the donor/acceptor interface.This work is of great significance for promoting the industrialization of OSCs.展开更多
High-temperature solid lubricant coatings with decent lubrication performance are essential in critical processes of metal forming and aerospace.However,their preparation is formidably challenging due to the harsh wor...High-temperature solid lubricant coatings with decent lubrication performance are essential in critical processes of metal forming and aerospace.However,their preparation is formidably challenging due to the harsh working conditions.Here,we successfully developed a solid lubricant coating via a facile and eco-friendly approach by casting a homogeneous mixture of molybdenum disulfide(MoS_(2))and hexagonal boron nitride(h-BN)as lubricants,silicate as the binder,and water as the solvent onto a titanium alloy substrate.This solid lubricant coating exhibited excellent and stable tribological properties with a very low coefficient of friction(COF)of 0.080 at 1,000℃,yet in an open-air atmosphere.This superior lubrication behavior is attributed to the synergistic effect between the base lubricants h-BN and MoS_(2),contributing to the formation of a coating for both lubrication and lubricant protection against oxidation at 1,000℃in an open-air environment.This work largely extends the operation temperature range of the crucial lubricant MoS_(2)in an open-air atmosphere and further sheds valuable light on the design of high-temperature solid lubricants via the synergistic effect between base lubricants.展开更多
Organic solar cells(OSCs)have emerged as a promising solution for sustainable energy production,offering advantages such as a low carbon footprint,short energy payback period,and compatibility with eco-solvents.Howeve...Organic solar cells(OSCs)have emerged as a promising solution for sustainable energy production,offering advantages such as a low carbon footprint,short energy payback period,and compatibility with eco-solvents.However,the use of hazardous solvents continues to dominate the best-performing OSCs,mainly because of the challenges of controlling phase separation and domain crystallinity in eco-solvents.In this study,we combined the solvent vapor treatment of CS2 and thermal annealing to precisely control the phase separation and domain crystallinity in PM6:M-Cl and PM6:O-Cl systems processed with the eco-solvent o-xylene.This method resulted in a maximum power conversion efficiency(PCE)of 18.4%,which is among the highest values reported for sustainable binary OSCs.Furthermore,the fabrication techniques were transferred from spin coating in a nitrogen environment to blade printing in ambient air,retaining a PCE of 16.0%,showing its potential for high-throughput and scalable production.In addition,a comparative analysis of OSCs processed with hazardous and green solvents was conducted to reveal the differences in phase aggregation.This work not only underscores the significance of sustainability in OSCs but also lays the groundwork for unlocking the full potential of open-air-printable sustainable OSCs for commercialization.展开更多
Taking the input and reflected waves into account,the relationship between the acoustic impedance at the end and the input of a system were theoretically analyzed.Closed and open acoustic configurations that influence...Taking the input and reflected waves into account,the relationship between the acoustic impedance at the end and the input of a system were theoretically analyzed.Closed and open acoustic configurations that influence the pressure,volumetric velocity,impedance and acoustic work were compared in detail.Based on the above investigation,an open-air traveling-wave thermoacoustic generator was designed and fabricated.It is composed of a looped tube,a resonator open at one end,a regenerator,and hot and cold heat exchangers.It is a small scale and simple configuration.The resonant frequency is 74 Hz at 1 bar in air.The maximum acoustic pressures at the open end and 0.5 m far away from the open end are 133.4 dB and 101 dB from a reference value of 20μPa when the heating power was 210 W,respectively.Acoustic pressure is reasonable for practical application as a low-frequency acoustic source.In further work,we believe that the acoustic pressure at the open end can achieve 150 dB,which could be a solution to problems in existing acoustic generators.These problems include low acoustic pressure and system complexity.It can be used as a basic acoustic source for low frequency and long-range noise experiments,and as a supply for high acoustic pressures necessary for industrial sources.展开更多
文摘Climate crises necessitate adaptive,cost-effective,and community-driven strategies to enhance urban resilience.Tactical urban design,which includes temporary and experimental interventions,is becoming increasingly vital,particularly in indigenous contexts.This study explores the spatial agency approach within tactical urbanism,emphasizing low-technology techniques,indigenous knowledge,and decentralized design as active elements in transforming public spaces.It aims to review recent trends and alternative tactical strategies in indigenous settings while identifying the attributes and mechanisms that contribute to the creation of sustainable public spaces through spatial agency.Employing an interpretive qualitative methodology that includes case studies and content analysis,the research focuses on the Open-Air Lab in Dakar,Senegal(Codesign Lab,Paolo Cascone).This project,a small-scale public infrastructure initiative born from participatory design,exemplifies a hybrid model that combines traditional craftsmanship,low-tech digital fabrication,and environmentally conscious solutions.The findings indicate that framing spatial agency as an actor-network process brings marginalized actors and practices to the forefront,fostering empowerment,social synergy,and climate-responsive design.The study advocates for a shift in tactical urban design from ephemeral placemaking toward long-term,adaptive strategies grounded in local materiality,community engagement,knowledge systems,and decentralized networks.These insights reshape the understanding of urban adaptability and provide practical guidance for architects and planners aiming to create inclusive,climate-resilient public spaces in indigenous and Global South contexts.
文摘Language plays a significant role in business,trade and commerce.Bargaining in open-air markets often involves the speech act of negotiating,compromising and manoeuvring,which could either result in conflict or persuasion of the potential buyer to patronize a seller.This article examined the sociolinguistic aspects of language use between sellers and buyers in Ipata,a popular market in Ilorin,north-central Nigeria.The call strategy,spiel,honorification,pragmatic mechanics as well as sociolinguistic style employed by vendors were observed.The objectives of the study were to:identify the number of languages used in Ipata market;investigate the factors that influence the choice of any of the languages used between sellers and buyers at a particular time;analyze their sociolinguistic and stylistic features;and discuss some of the barriers that could cause intercultural communication breakdown between sellers and buyers in a market situation.Oral interview,systematic observation and Bauman’s(2001)method of street recording were used to gather data for the study.Sixty-five people comprising thirty-six females and twenty-nine males were interviewed.The survey which spanned three months discovered that open-air markets bear some universal features,however,due to cultural relativity,variations occur.To this end,it was established that Ipata market harbours different languages;it also identified calls and spiels with their characteristic stylistic,sociolinguistic and discourse features in the market.In conclusion,the study argued that studying the verbal discourse of marketplaces is significant as it defines what the language-culture-society-relationship is all about.
文摘The framing of this theme would contribute to a better analysis of the benefits of open-air quarrying in Zinder, and should make it possible to understand and measure the socio-environmental externalities of this type of activity in an urban environment. The approach method consisted of carrying out surveys combined with field observations and interviews with the various stakeholders as well as the local population. The results obtained made it possible to identify both positive and negative impacts. The positive impacts are above all the advantages derived from these aggregate quarries, in particular, the creation of direct and permanent jobs and the increase in community income. The price of piling up a truck costs around 28,000 CFA ($56 CAN) and that of loading is around 10,000 F CFA ($20 CAN). This has the effect of removing young people (20 - 39 years old) from the circuit of migration outside the region and even the country. The possibility of using the extraction sites by the local population was identified, in terms of profits relating to fish farming, off-season crops, animal drinking and reclaimed plots. The study also noted negative externalities, such as the temptation of young boys to become involved in extractive activities for immediate gains at the expense of school attendance. Added to this is the upheaval in the topography of the urban landscape, pollution and nuisances (noise, visual and olfactory), while the disappearance or clogging of quarry ponds is the cause of frequent flooding in the neighborhoods. In short, corrective measures (e.g. the revegetation of sites) certainly make it possible to minimize the harmful impacts on the urban environment. But, to improve the performance and organizational capacity of the quarrying industry in Niger, even stronger regulation, training and awareness of stakeholders prove to be the necessary measures.
基金supported by the National Natural Science Foundation of China(No.52103240)the Science and Technology Department of Henan Province(No.242301420056).
文摘Fabricating organic solar cells(OSCs)in open-air and room-temperature environments is essential for cost-effective roll-to-roll printing,but its performance is limited by non-ideal block and surface morphology of active layer.Herein,we demonstrate a record power conversion efficiency(PCE)of 19.72%in open-air and as-cast processed devices by using a lowcost terpolymer donor(PTQ20-5)to optimize the block and surface morphology.Compared with the counterpart PTQ10,PTQ20-5 shows increased hydrophobicity,which can better prevent the intrusion of H_(2)O molecules in the film formation process in open-air environment,giving excellent humidity tolerance of corresponding devices.Moreover,the enhanced dielectric constant results in reduced exciton binding energy and improved charge transport of PTQ20-5,leading to improved charge separation and transfer,and suppressed carrier recombination in the devices.Besides,the PTQ20-5-based film has more appropriate block morphological features of balanced molecular self-assembly and phase separation,which simultaneously promotes the charge carrier transport and inhibits the carrier recombination at the donor/acceptor interface.This work is of great significance for promoting the industrialization of OSCs.
基金supported by the National Key R&D Program of China(No.2020YFA0711003)the National Natural Science Foundation of China(Nos.51925506 and 52305198)the XPLORER PRIZE,and the China Postdoctoral Science Foundation(No.2023M731936).
文摘High-temperature solid lubricant coatings with decent lubrication performance are essential in critical processes of metal forming and aerospace.However,their preparation is formidably challenging due to the harsh working conditions.Here,we successfully developed a solid lubricant coating via a facile and eco-friendly approach by casting a homogeneous mixture of molybdenum disulfide(MoS_(2))and hexagonal boron nitride(h-BN)as lubricants,silicate as the binder,and water as the solvent onto a titanium alloy substrate.This solid lubricant coating exhibited excellent and stable tribological properties with a very low coefficient of friction(COF)of 0.080 at 1,000℃,yet in an open-air atmosphere.This superior lubrication behavior is attributed to the synergistic effect between the base lubricants h-BN and MoS_(2),contributing to the formation of a coating for both lubrication and lubricant protection against oxidation at 1,000℃in an open-air environment.This work largely extends the operation temperature range of the crucial lubricant MoS_(2)in an open-air atmosphere and further sheds valuable light on the design of high-temperature solid lubricants via the synergistic effect between base lubricants.
基金Scientific Research Startup Fund for Shenzhen High-Caliber Personnel of Shenzhen Polytechnic,Grant/Award Number:6022310038kNational Natural Science Foundation of China,Grant/Award Number:62004129+7 种基金Shenzhen Science and Technology Innovation Commission,Grant/Award Numbers:JCYJ20200109105003940,20220811205532001Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2023A1515011677Innovation Team Project of Guangdong,Grant/Award Number:2022KCXTD055China Postdoctoral Science Foundation,Grant/Award Number:2022M720156Post-Doctoral Foundation Project of Shenzhen Polytechnic,Grant/Award Number:6022331001KKing Abdullah University of Science and Technology(KAUST),Grant/Award Numbers:ORFSCRG11-2022-5045,OSR-CARF/CCF-3079Research Grants Council of Hong Kong,Grant/Award Numbers:C7018-20G,CRF C5037-18G,15221320Hong Kong Polytechnic University funds,Grant/Award Numbers:Q-CDA5,8-8480。
文摘Organic solar cells(OSCs)have emerged as a promising solution for sustainable energy production,offering advantages such as a low carbon footprint,short energy payback period,and compatibility with eco-solvents.However,the use of hazardous solvents continues to dominate the best-performing OSCs,mainly because of the challenges of controlling phase separation and domain crystallinity in eco-solvents.In this study,we combined the solvent vapor treatment of CS2 and thermal annealing to precisely control the phase separation and domain crystallinity in PM6:M-Cl and PM6:O-Cl systems processed with the eco-solvent o-xylene.This method resulted in a maximum power conversion efficiency(PCE)of 18.4%,which is among the highest values reported for sustainable binary OSCs.Furthermore,the fabrication techniques were transferred from spin coating in a nitrogen environment to blade printing in ambient air,retaining a PCE of 16.0%,showing its potential for high-throughput and scalable production.In addition,a comparative analysis of OSCs processed with hazardous and green solvents was conducted to reveal the differences in phase aggregation.This work not only underscores the significance of sustainability in OSCs but also lays the groundwork for unlocking the full potential of open-air-printable sustainable OSCs for commercialization.
基金supported by the National Natural Science Foundation of China(50806081)
文摘Taking the input and reflected waves into account,the relationship between the acoustic impedance at the end and the input of a system were theoretically analyzed.Closed and open acoustic configurations that influence the pressure,volumetric velocity,impedance and acoustic work were compared in detail.Based on the above investigation,an open-air traveling-wave thermoacoustic generator was designed and fabricated.It is composed of a looped tube,a resonator open at one end,a regenerator,and hot and cold heat exchangers.It is a small scale and simple configuration.The resonant frequency is 74 Hz at 1 bar in air.The maximum acoustic pressures at the open end and 0.5 m far away from the open end are 133.4 dB and 101 dB from a reference value of 20μPa when the heating power was 210 W,respectively.Acoustic pressure is reasonable for practical application as a low-frequency acoustic source.In further work,we believe that the acoustic pressure at the open end can achieve 150 dB,which could be a solution to problems in existing acoustic generators.These problems include low acoustic pressure and system complexity.It can be used as a basic acoustic source for low frequency and long-range noise experiments,and as a supply for high acoustic pressures necessary for industrial sources.
