This paper examines project⁃based policies and regulations implemented globally to control and mitigate emissions from diesel⁃powered construction equipment.This study systematically reviews and analyzes various manag...This paper examines project⁃based policies and regulations implemented globally to control and mitigate emissions from diesel⁃powered construction equipment.This study systematically reviews and analyzes various managerial,regulatory,and technical measures adopted across countries and regions,mostly of advanced economy.Key strategies of control include setting emission thresholds,idling restrictions,perform remote online monitoring,operational time limits,setting low emission zones,and enforced registration systems.The review highlights the rationale,implementation details,and experiences gained from these localized approaches,reduces localized emission sources,improve urban air quality and environmental management efficiency.展开更多
Semiconductor photocatalysis can be operated over a narrow pH range for wastewater treatment. In this study, a simulated solar-light-mediated bismuth tungstate (SSL/Bi2WO6) process is found to be effective for norflox...Semiconductor photocatalysis can be operated over a narrow pH range for wastewater treatment. In this study, a simulated solar-light-mediated bismuth tungstate (SSL/Bi2WO6) process is found to be effective for norfloxacin degradation over a narrow pH range. To broaden the operating pH range of the SSL/Bi2WO6 process, an NH4+ buffer system and an Fe3+ salt were introduced under extremely basic and acidic pH conditions, respectively. The NH4+ buffer system continuously supplied hydroxyl ions to generate ·OH radicals and prevented acidification of the solution, resulting in improved norfloxacin removal and mineralization removal under alkaline conditions. In contrast, the Fe3+ salt offered an additional homogeneous photo-sensitization pathway. The former treatment assisted in norfloxacin decay and the latter increased the collision frequency between the photo-generated hole and hydroxyl ions. Moreover, the effect of parameters such as pH and Fe3+ dosage was optimized.展开更多
Bismuth‐based photocatalysts are a class of excellent visible‐light photocatalysts;however,their redox activity is relatively poor and the efficiency of photogenerated carrier separation is low,limiting their develo...Bismuth‐based photocatalysts are a class of excellent visible‐light photocatalysts;however,their redox activity is relatively poor and the efficiency of photogenerated carrier separation is low,limiting their development and application in the field of photocatalysis.To address these issues,a series of polyoxometalate PW_(12)O_(40)^(3–)‐doped Bi_(2)O_(3–x)/Bi Schottky photocatalysts PW_(12)@Bi_(2)O_(3–x)/Bi‐n(PBOB‐n,where n is the amount of NaBH4,i.e.,6,12,18,24,and 48 mg)were prepared by a simple electrospinning/calcination/in‐situ NaBH4 reduction method.In this composite photocatalyst,the doping of PW_(12) could effectively adjust the electronic structure of Bi_(2)O_(3–x) and improve its redox properties.As a shallow electron trap,PW_(12) promoted the separation of the photogenerated carriers.Furthermore,desirable Schottky junction between the metal Bi nanoparticles and PW_(12)@Bi_(2)O_(3–x) further accelerated the separation of the photogenerated carriers.The synergistic effect of the aforementioned factors endowed PBOB‐n with excellent photocatalytic activity.Among the samples,PBOB‐18 exhibited superior photocatalytic activity.Under visible‐light irradiation,93.7%(20 mg catalyst)of 20 ppm tetrabromobisphenol A(TBBPA,20 mL)was degraded in 60 min.Its activity was 4.4 times higher than that of Bi_(2)O_(3).PBOB‐18 also exhibited an ultrahigh photocatalytic performance for the removal of NO.Its removal rate(600 ppb)reached 83.3%in 30 min,making it one of the most active Bi‐based photocatalysts.Furthermore,the photocatalytic mechanisms of PBOB‐18 for TBBPA and NO have been proposed.This work provides a new direction and reference for the design of low‐cost,efficient,stable,and versatile photocatalysts.展开更多
A synergistic UV/TiO2/Fenton(PCF)process is investigated for the degradation of ibuprofen(IBP)at circumneutral pH.The IBP decay in the PCF process is much faster than that with the conventional UV,UV/H2O2,Fenton,photo...A synergistic UV/TiO2/Fenton(PCF)process is investigated for the degradation of ibuprofen(IBP)at circumneutral pH.The IBP decay in the PCF process is much faster than that with the conventional UV,UV/H2O2,Fenton,photo‐Fenton,and photocatalysis processes.The kinetics analysis showed that the IBP decay follows a two‐stage pseudo‐first order profile,that is,a fast IBP decay(k1)followed by a slow decay(k2).The effects of various parameters,including initial pH level,dosage of Fenton’s reagent and TiO2,wavelength of UV irradiation,and initial IBP concentration,are evaluated.The optimum pH level,[Fe2+]0,[Fe2+]0/[H2O2]0 molar ratio,and[TiO2]0 are determined to be approximately 4.22,0.20 mmol/L,1/40,and 1.0 g/L,respectively.The IBP decay at circumneutral pH(i.e.,6.0–8.0 for wastewater)shows the same IBP decay efficiency as that at the optimum pH of 4.22 after 30 min,which suggests that the PCF process is applicable for the treatment of wastewater in the circumneutral pH range.The lnk1 and lnk2 are observed to be linearly correlated to 1/pH0,[IBP]0,[H2O2]0,[H2O2]0/[Fe2+]0 and ln[TiO2]0.Mathematical models are therefore derived to predict the IBP decay.展开更多
To address the control of low frequency noises,we propose an new perforated thin-plate acoustic metamaterials with the attachable Helmholtz resonator(AHR)which can be directly attached to the existing structure to sup...To address the control of low frequency noises,we propose an new perforated thin-plate acoustic metamaterials with the attachable Helmholtz resonator(AHR)which can be directly attached to the existing structure to suppress acoustic radiation.Sound transmission loss of the aluminium plate with AHR has been simulated using the finite element method under a normal incident plane sound wave.The results show that AHR works well in the 50—500 Hz frequency band,with two peaks of insulation occurring and the corresponding frequency of the first insulation peak dropping to around 120 Hz.The study of the effects of plate thickness,cavity depth,perforation radius and perforation length on the sound insulation performance of metamaterials demonstrates that the effective suppression of acoustic radiation at specific frequencies can be achieved by changing the acoustic radiation properties of the structure.展开更多
Nickel(Ni)-based materials act as one of the most promising candidates as platinum-group-metal-free(PGM-free)electrocatalysts for hydrogen oxidation reaction(HOR)in alkaline solution.Nevertheless,the electrocatalytic ...Nickel(Ni)-based materials act as one of the most promising candidates as platinum-group-metal-free(PGM-free)electrocatalysts for hydrogen oxidation reaction(HOR)in alkaline solution.Nevertheless,the electrocatalytic activity of pure Ni is significantly limited due to the sluggish kinetics under alkaline condition.To accelerate the kinetics,constructing heterostructures and nitride structures have been developed as two representative strategies.Here,we combined the two methods and presented a facile synthesis of the sheet-like Ni_(3)N/MoO_(2)in-plane heterostructures for enhanced HOR in alkaline electrolytes.Relative to Ni or Ni_(3)N,the Ni_(3)N/MoO_(2)in-plane heterostructures exhibited a significantly increased mass activity by 8.6-fold or 4.4-fold,respectively.Mechanistic studies revealed that the enhanced activity of Ni_(3)N/MoO_(2)could be attributed to the weakened hydrogen adsorption and strengthened hydroxyl adsorption.This work provides a facile approach to design high-efficiency catalysts for hydrogen-oxidation catalysis and beyond.展开更多
Dispersing metals from nanoparticles into clusters or single atoms often exhibits unique properties such as the inhibition of structure-sensitive side reactions.Here,we reported the use of ion exchange(IE)methods and ...Dispersing metals from nanoparticles into clusters or single atoms often exhibits unique properties such as the inhibition of structure-sensitive side reactions.Here,we reported the use of ion exchange(IE)methods and direct hydrogen reduction to achieve high dispersion of Co species on zincosilicate.The obtained 2Co/Zn-4-IE catalyst achieved an initial propane conversion of 41.4%at a temperature of 550℃in a 25%propane and 75%nitrogen atmosphere for propane dehydrogenation.Visualization of the presence of Co species within specific rings(alpha-α,beta-βand delta-δ)was obtained by aberration-corrected scanning transmission electron microscopy.A series of Fourier transform infrared spectra confirmed the anchoring of Co by specific hydroxyl groups in zincosilicate and the specific coordination environment of Co and its presence in the rings essentially as a single site.The framework Zn for the modulation of the microenvironment and the presence of Co species as Lewis acid active sites(Co-O4)was also supported by density functional theory calculations.展开更多
As social and economic dynamics continue to evolve and the demand for companionship increases,pet ownership has become an increasingly popular lifestyle choice.Pet parks,as a new form of urban public space,are gaining...As social and economic dynamics continue to evolve and the demand for companionship increases,pet ownership has become an increasingly popular lifestyle choice.Pet parks,as a new form of urban public space,are gaining significant attention.This study,grounded in the theory of spatial justice,employs a combination of questionnaires and semi-structured interviews to evaluate four representative pet parks in Hong Kong,China.It explores how pet parks,as inclusive green infrastructure in high-density environments,contribute to urban community well-being and broader spatial justice.The study reveals the conflicts between pet owners and non-pet owners regarding the rights to use public spaces,examining how to guarantee the spatial rights of specific groups while avoiding harm to others.The findings indicate that green space availability,sociability and participation,walkability,safety,and flexibility in pet parks play a positive role in achieving urban spatial justice.However,pet parks also face challenges related to social exclusion and safety,requiring a balance between promoting community integration and ensuring public safety.This study offers valuable insights for the development of pet parks,the creation of vibrant and diverse public spaces,and the promotion of harmonious human-animal environments in cities across China and other Asian countries.展开更多
基金Research Grants Council of the Hong Kong Special Administrative Region,China(U15239024)。
文摘This paper examines project⁃based policies and regulations implemented globally to control and mitigate emissions from diesel⁃powered construction equipment.This study systematically reviews and analyzes various managerial,regulatory,and technical measures adopted across countries and regions,mostly of advanced economy.Key strategies of control include setting emission thresholds,idling restrictions,perform remote online monitoring,operational time limits,setting low emission zones,and enforced registration systems.The review highlights the rationale,implementation details,and experiences gained from these localized approaches,reduces localized emission sources,improve urban air quality and environmental management efficiency.
基金supported by the National Science Foundation of China(41877481,41503102)the open project of the State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Science(SKLLQG1729)+2 种基金the China Postdoctoral Science Foundation(2018M643669)the Fundamental Research Funds for the Central Universities(2018249)the "Hundred Talent Program" of the Chinese Academy of Sciences~~
文摘Semiconductor photocatalysis can be operated over a narrow pH range for wastewater treatment. In this study, a simulated solar-light-mediated bismuth tungstate (SSL/Bi2WO6) process is found to be effective for norfloxacin degradation over a narrow pH range. To broaden the operating pH range of the SSL/Bi2WO6 process, an NH4+ buffer system and an Fe3+ salt were introduced under extremely basic and acidic pH conditions, respectively. The NH4+ buffer system continuously supplied hydroxyl ions to generate ·OH radicals and prevented acidification of the solution, resulting in improved norfloxacin removal and mineralization removal under alkaline conditions. In contrast, the Fe3+ salt offered an additional homogeneous photo-sensitization pathway. The former treatment assisted in norfloxacin decay and the latter increased the collision frequency between the photo-generated hole and hydroxyl ions. Moreover, the effect of parameters such as pH and Fe3+ dosage was optimized.
文摘Bismuth‐based photocatalysts are a class of excellent visible‐light photocatalysts;however,their redox activity is relatively poor and the efficiency of photogenerated carrier separation is low,limiting their development and application in the field of photocatalysis.To address these issues,a series of polyoxometalate PW_(12)O_(40)^(3–)‐doped Bi_(2)O_(3–x)/Bi Schottky photocatalysts PW_(12)@Bi_(2)O_(3–x)/Bi‐n(PBOB‐n,where n is the amount of NaBH4,i.e.,6,12,18,24,and 48 mg)were prepared by a simple electrospinning/calcination/in‐situ NaBH4 reduction method.In this composite photocatalyst,the doping of PW_(12) could effectively adjust the electronic structure of Bi_(2)O_(3–x) and improve its redox properties.As a shallow electron trap,PW_(12) promoted the separation of the photogenerated carriers.Furthermore,desirable Schottky junction between the metal Bi nanoparticles and PW_(12)@Bi_(2)O_(3–x) further accelerated the separation of the photogenerated carriers.The synergistic effect of the aforementioned factors endowed PBOB‐n with excellent photocatalytic activity.Among the samples,PBOB‐18 exhibited superior photocatalytic activity.Under visible‐light irradiation,93.7%(20 mg catalyst)of 20 ppm tetrabromobisphenol A(TBBPA,20 mL)was degraded in 60 min.Its activity was 4.4 times higher than that of Bi_(2)O_(3).PBOB‐18 also exhibited an ultrahigh photocatalytic performance for the removal of NO.Its removal rate(600 ppb)reached 83.3%in 30 min,making it one of the most active Bi‐based photocatalysts.Furthermore,the photocatalytic mechanisms of PBOB‐18 for TBBPA and NO have been proposed.This work provides a new direction and reference for the design of low‐cost,efficient,stable,and versatile photocatalysts.
文摘A synergistic UV/TiO2/Fenton(PCF)process is investigated for the degradation of ibuprofen(IBP)at circumneutral pH.The IBP decay in the PCF process is much faster than that with the conventional UV,UV/H2O2,Fenton,photo‐Fenton,and photocatalysis processes.The kinetics analysis showed that the IBP decay follows a two‐stage pseudo‐first order profile,that is,a fast IBP decay(k1)followed by a slow decay(k2).The effects of various parameters,including initial pH level,dosage of Fenton’s reagent and TiO2,wavelength of UV irradiation,and initial IBP concentration,are evaluated.The optimum pH level,[Fe2+]0,[Fe2+]0/[H2O2]0 molar ratio,and[TiO2]0 are determined to be approximately 4.22,0.20 mmol/L,1/40,and 1.0 g/L,respectively.The IBP decay at circumneutral pH(i.e.,6.0–8.0 for wastewater)shows the same IBP decay efficiency as that at the optimum pH of 4.22 after 30 min,which suggests that the PCF process is applicable for the treatment of wastewater in the circumneutral pH range.The lnk1 and lnk2 are observed to be linearly correlated to 1/pH0,[IBP]0,[H2O2]0,[H2O2]0/[Fe2+]0 and ln[TiO2]0.Mathematical models are therefore derived to predict the IBP decay.
文摘To address the control of low frequency noises,we propose an new perforated thin-plate acoustic metamaterials with the attachable Helmholtz resonator(AHR)which can be directly attached to the existing structure to suppress acoustic radiation.Sound transmission loss of the aluminium plate with AHR has been simulated using the finite element method under a normal incident plane sound wave.The results show that AHR works well in the 50—500 Hz frequency band,with two peaks of insulation occurring and the corresponding frequency of the first insulation peak dropping to around 120 Hz.The study of the effects of plate thickness,cavity depth,perforation radius and perforation length on the sound insulation performance of metamaterials demonstrates that the effective suppression of acoustic radiation at specific frequencies can be achieved by changing the acoustic radiation properties of the structure.
文摘Nickel(Ni)-based materials act as one of the most promising candidates as platinum-group-metal-free(PGM-free)electrocatalysts for hydrogen oxidation reaction(HOR)in alkaline solution.Nevertheless,the electrocatalytic activity of pure Ni is significantly limited due to the sluggish kinetics under alkaline condition.To accelerate the kinetics,constructing heterostructures and nitride structures have been developed as two representative strategies.Here,we combined the two methods and presented a facile synthesis of the sheet-like Ni_(3)N/MoO_(2)in-plane heterostructures for enhanced HOR in alkaline electrolytes.Relative to Ni or Ni_(3)N,the Ni_(3)N/MoO_(2)in-plane heterostructures exhibited a significantly increased mass activity by 8.6-fold or 4.4-fold,respectively.Mechanistic studies revealed that the enhanced activity of Ni_(3)N/MoO_(2)could be attributed to the weakened hydrogen adsorption and strengthened hydroxyl adsorption.This work provides a facile approach to design high-efficiency catalysts for hydrogen-oxidation catalysis and beyond.
文摘Dispersing metals from nanoparticles into clusters or single atoms often exhibits unique properties such as the inhibition of structure-sensitive side reactions.Here,we reported the use of ion exchange(IE)methods and direct hydrogen reduction to achieve high dispersion of Co species on zincosilicate.The obtained 2Co/Zn-4-IE catalyst achieved an initial propane conversion of 41.4%at a temperature of 550℃in a 25%propane and 75%nitrogen atmosphere for propane dehydrogenation.Visualization of the presence of Co species within specific rings(alpha-α,beta-βand delta-δ)was obtained by aberration-corrected scanning transmission electron microscopy.A series of Fourier transform infrared spectra confirmed the anchoring of Co by specific hydroxyl groups in zincosilicate and the specific coordination environment of Co and its presence in the rings essentially as a single site.The framework Zn for the modulation of the microenvironment and the presence of Co species as Lewis acid active sites(Co-O4)was also supported by density functional theory calculations.
文摘As social and economic dynamics continue to evolve and the demand for companionship increases,pet ownership has become an increasingly popular lifestyle choice.Pet parks,as a new form of urban public space,are gaining significant attention.This study,grounded in the theory of spatial justice,employs a combination of questionnaires and semi-structured interviews to evaluate four representative pet parks in Hong Kong,China.It explores how pet parks,as inclusive green infrastructure in high-density environments,contribute to urban community well-being and broader spatial justice.The study reveals the conflicts between pet owners and non-pet owners regarding the rights to use public spaces,examining how to guarantee the spatial rights of specific groups while avoiding harm to others.The findings indicate that green space availability,sociability and participation,walkability,safety,and flexibility in pet parks play a positive role in achieving urban spatial justice.However,pet parks also face challenges related to social exclusion and safety,requiring a balance between promoting community integration and ensuring public safety.This study offers valuable insights for the development of pet parks,the creation of vibrant and diverse public spaces,and the promotion of harmonious human-animal environments in cities across China and other Asian countries.
