In this paper, CiteSpace, a bibliometrics software, was adopted to collect research papers published on the Web of Science, which are relevant to biological model and effluent quality prediction in activated sludge pr...In this paper, CiteSpace, a bibliometrics software, was adopted to collect research papers published on the Web of Science, which are relevant to biological model and effluent quality prediction in activated sludge process in the wastewater treatment. By the way of trend map, keyword knowledge map, and co-cited knowledge map, specific visualization analysis and identification of the authors, institutions and regions were concluded. Furthermore, the topics and hotspots of water quality prediction in activated sludge process through the literature-co-citation-based cluster analysis and literature citation burst analysis were also determined, which not only reflected the historical evolution progress to a certain extent, but also provided the direction and insight of the knowledge structure of water quality prediction and activated sludge process for future research.展开更多
Developing highly-active,earth-abundant non-precious-metal catalysts for hydrogen evolution reaction(HER)in alkaline solution would be beneficial to sustainable energy storage.Perovskite oxides are generally regarded ...Developing highly-active,earth-abundant non-precious-metal catalysts for hydrogen evolution reaction(HER)in alkaline solution would be beneficial to sustainable energy storage.Perovskite oxides are generally regarded as low-active HER catalysts,due to their inapposite hydrogen adsorption and water dissociation.Here,we report a detailed study on perovskite LaCoO_(3)epitaxial thin films as a model catalyst to significantly enhance the HER performance via an electrochemical activation process.As a result,the overpotential for the activation films to achieve a current density of 0.36 m A/cm^(2)is 238 m V,reduced by more than 200 m V in comparison with that of original samples.Structural characterization revealed the activation process dramatically increases the concentration of oxygen vacancies(Vo)on the surface of LaCoO_(3).We established the relationship between the electronic structure induced by Vo and the enhanced HER activity.Further theoretical calculations revealed that the Vo optimizes the hydrogen adsorption and dissociation of water on the surface of LaCoO_(3)thin films,thus improving the HER catalytic activity.This work may promote a deepened understanding of perovskite oxides for HER mechanism by Vo adjusting and a new avenue for designing highly active electrochemical catalysts in alkaline solution.展开更多
The microstructural properties and electrochemical performance of zinc(Zn)sacrificial anodes during strain-induced melt activation(SIMA)were investigated in this study.The samples were subjected to a compressive ratio...The microstructural properties and electrochemical performance of zinc(Zn)sacrificial anodes during strain-induced melt activation(SIMA)were investigated in this study.The samples were subjected to a compressive ratio of 20%-50% at various temperatures(425-435℃)and durations(5-30 min).Short-term electrochemical tests(anode tests)based on DNV-RP-B401 and potentiodynamic polarization tests were performed in 3.5wt%NaCl solution to evaluate the electrochemical efficiency and corrosion behavior of the samples,respectively.The electrochemical test results for the optimum sample confirmed that the corrosion current density declined by 90% and the anode efficiency slightly decreased relative to that of the raw sample.Energy-dispersive X-ray spectroscopy,scanning electron microscopy,metallographic images,and microhardness profiles showed the accumulation of alloying elements on the boundary and the conversion of uniform corrosion into localized corrosion,hence the decrease of the Zn sacrificial anode’s efficiency after the SIMA process.展开更多
According to the second law of thermodynamics,spontaneous chemical processes will ultimately reach the equilibrium state with the lowest energy.However,in biological systems,there are numerous highenergy states far fr...According to the second law of thermodynamics,spontaneous chemical processes will ultimately reach the equilibrium state with the lowest energy.However,in biological systems,there are numerous highenergy states far from equilibrium.One typical example is the transmembrane ion-concentration gradient,which plays crucial roles in maintaining homeostasis,regulating cell volume,and enabling cell signaling.Transmembrane ion-concentration gradient is achieved by an active transport process that requires the input of energy and the action of pump proteins.Replicating this process with synthetic supramolecular systems is particularly challenging,requiring both the input of energy and very specific,spatiotemporal control over ion uptake and release.In nature,pump proteins,such as protein-based ion channels,have evolved highly intricate architectures to perform this function.In contrast,Aprahamian and coworkers recently developed a much simpler smallmolecule system that functions as a molecular ion pump,utilizing light energy to pump chloride ions across a hydrophobic barrier against the concentration gradient[1].展开更多
The utilization of biowaste to the activated carbon(AC)as electrode material is conducive to alleviating the energy crisis and promoting the high value-added.The popular KOH activation has been applied for years,but r...The utilization of biowaste to the activated carbon(AC)as electrode material is conducive to alleviating the energy crisis and promoting the high value-added.The popular KOH activation has been applied for years,but rare report clarified the difference of dry and wet activation,with which the batch producing technique could be different.Here nitrogen doped hierarchical AC was derived from wood chip by a wet or dry KOH activation.The surface area,framework structure and surface feature were characterized to reveal the effect of wet and dry activation.1.44 at%of nitrogen doped AC was made by dry KOH activation,which was higher than the AC derived from wet KOH activation with 1.36 at%of nitrogen.Their electrochemical properties were investigated in 6 mol L^(-1)of KOH,the capacitance of wAC was 401 F g^(-1)at 0.5 A g^(-1),but dAC possessed a capacitance of 215 F g^(-1).These indicated that AC obtained by using wet KOH activation displayed a potential application in energy field.展开更多
Structure evolution of an Al-Zn wrought alloy in remelting processing in thestrain induced melt activated (SIMA) serai-solid procedure was observed, and effects of factors, theremelting temperature, the holding time, ...Structure evolution of an Al-Zn wrought alloy in remelting processing in thestrain induced melt activated (SIMA) serai-solid procedure was observed, and effects of factors, theremelting temperature, the holding time, and the compression strain, on structures and grain sizesof the alloy were investigated. The results show that (1) the proper temperature of remelting is inthe range of 610 to 615℃; (2) the grain size in specimen with greater compression strain is smallerthan that with smaller compression strain in condition of the same remelting temperature andholding time, and the grain size in local area with great local equivalent strain is smaller thanthat with small one; (3) liquid occurs in form of cluster in matrix during remelting and itsquantity increases with remelting time increasing; liquid in specimen with great compression strainoccurs earlier than that with small one, and quantity of liquid in the center of specimen withgreater local equivalent strain is greater than that in the two ends of it; (4) distortion energyafter deforming in matrix of the alloy is the significant factor to activate melting of matrix atlocal area with great local equivalent strain.展开更多
To develop technically feasible and economically favorable dynamic process control(DPC)strategies for an alternating activated sludge(AAS)system,a bench-scale continuous-flow alternating aerobic and anoxic reactor,per...To develop technically feasible and economically favorable dynamic process control(DPC)strategies for an alternating activated sludge(AAS)system,a bench-scale continuous-flow alternating aerobic and anoxic reactor,performing short-cut nitrogen removal from real domestic wastewater was operated under different control strategies for more than five months.A fixed-time control(FTC) study showed that bending-points on pH and oxidation-reduction potential(ORP)profiles accurately coincided with the major biologic...展开更多
The removal efficiencies of heavy metals(As, Cr, Cu, Ni, Pb and Zn) were investigated in the 17 operating municipal wastewater treatment plants(WWTPs) and compared with those in four main activated sludge processes. S...The removal efficiencies of heavy metals(As, Cr, Cu, Ni, Pb and Zn) were investigated in the 17 operating municipal wastewater treatment plants(WWTPs) and compared with those in four main activated sludge processes. Significant differences of heavy metal removal efficiencies were observed among four activated sludge processes. The removal efficiency for As(75.5%) in the oxidation ditch(OD) process is significantly higher than that in the conventional activated sludge(CAS) process(38.6%) or sequencing batch reactor(SBR) process(51.4%). The mean removal efficiencies for Cu and Ni in the OD process are 90.5% and 46.7%, respectively, while low mean removal efficiencies are observed for Cu(69.9%) and Ni(16.5%), respectively, in the SBR process. The removal efficiencies for Cu and Ni in the OD process are significantly higher than those in the anaerobic-anoxic-oxic(A2-O) process. These results highlight the differences of removal efficiencies for heavy metals in different processes and should be considered when selecting a wastewater treatment process.展开更多
Two hybrid processes including ozonation-ceramic membrane-biological activated carbon （BAC） （Process A） and ceramic membrane-BAC （Process B） were compared to treat polluted raw water. The performance of hybrid p...Two hybrid processes including ozonation-ceramic membrane-biological activated carbon （BAC） （Process A） and ceramic membrane-BAC （Process B） were compared to treat polluted raw water. The performance of hybrid processes was evaluated with the removal efficiencies of turbidity, ammonia and organic matter. The results indicated that more than 99% of particle count was removed by both hybrid processes and ozonation had no significant effect on its removal. BAC filtration greatly improved the removal of ammonia. Increasing the dissolved oxygen to 30.0 mg/L could lead to a removal of ammonia with concentrations as high as 7.80 mg/L and 8.69 mg/L for Processes A and B, respectively. The average removal efficiencies of total organic carbon and ultraviolet absorbance at 254 nm （UV254, a parameter indicating organic matter with aromatic structure） were 49% and 52% for Process A, 51% and 48% for Process B, respectively. Some organic matter was oxidized by ozone and this resulted in reduced membrane fouling and increased membrane flux by 25%-30%. However, pre-ozonation altered the components of the raw water and affected the microorganisms in the BAC, which may impact the removals of organic matter and nitrite negatively.展开更多
A new Mg−10%Al−1%Zn−1%Si alloy with non-dendritic microstructure was prepared by strain induced melt activation(SIMA)process.The effect of compression ratio on the evolution of semisolid microstructure of the experime...A new Mg−10%Al−1%Zn−1%Si alloy with non-dendritic microstructure was prepared by strain induced melt activation(SIMA)process.The effect of compression ratio on the evolution of semisolid microstructure of the experimental alloy was investigated.The results indicate that the average size ofα-Mg grains decreases and spheroidizing tendency becomes more obvious with the compression ratios increasing from 0 to 40%.In addition,the eutectic Mg2Si phase in the Mg−10%Al−1%Zn−1%Si alloy transforms completely from the initial fishbone shape to globular shape by SIMA process.With the increasing of compression ratio,the morphology and average size of Mg2Si phases do not change obviously.The morphology modification mechanism of Mg2Si phase in Mg−10%Al−1%Zn−1%Si alloy by SIMA process was also studied.展开更多
As an important intermediate product, short-chain fatty acids（SCFAs） can be generated after hydrolysis and acidification from waste activated sludge, and then can be transformed to methane during anaerobic digestion...As an important intermediate product, short-chain fatty acids（SCFAs） can be generated after hydrolysis and acidification from waste activated sludge, and then can be transformed to methane during anaerobic digestion process. In order to obtain more SCFA and methane,most studies in literatures were centered on enhancing the hydrolysis of sludge anaerobic digestion which was proved as un-efficient. Though the alkaline pretreatment in our previous study increased both the hydrolysis and acidification processes, it had a vast chemical cost which was considered uneconomical. In this paper, a low energy consumption pretreatment method, i.e. enhanced the whole three stages of the anaerobic fermentation processes at the same time, was reported, by which hydrolysis and acidification were both enhanced, and the SCFA and methane generation can be significantly improved with a small quantity of chemical input. Firstly, the effect of different pretreated temperatures and pretreatment time on sludge hydrolyzation was compared. It was found that sludge pretreated at 100°C for 60 min can achieve the maximal hydrolyzation. Further, effects of different initial p Hs on acidification of the thermal pretreated sludge were investigated and the highest SCFA was observed at initial p H 9.0with fermentation time of 6 d, the production of which was 348.63 mg COD/g VSS（6.8 times higher than the blank test） and the acetic acid was dominant acid. Then, the mechanisms for this new pretreatment significantly improving SCFA production were discussed. Finally,the effect of this low energy consumption pretreatment on methane generation was investigated.展开更多
Objective: To determine the active process on dipeptide transport with proton-and energy-dependence in Caco-2 cells.Methods: A human intestinal cell monolayer(Caco-2) was used as the in vitro model of human small inte...Objective: To determine the active process on dipeptide transport with proton-and energy-dependence in Caco-2 cells.Methods: A human intestinal cell monolayer(Caco-2) was used as the in vitro model of human small intestine and cephalexin as the model substrate for dipeptide transporter(PepT1).Caco-2 cells grown on multiwell dishes(24 wells) and Transwell membrane filters were incubated in the culture medium. The transport and uptake experiments of cephalexin across apical membranes were then conducted with different temperature and different pH values.Uptake of cephalexin in Caco-2 cells gsown on multiple well dishes with addition of energy inhibitors(sodium azide,SA and 2,4-dinitrophenol,DNP) were then measured. Results: The accumulation of cephalexin into Caco-2 monolayers increased with the duration of culture.The uptake from the apical surface was markedly influenced by the pH of the apical medium,and the maximal uptake was achieved at pH 5.5;further acidification of the incubation medium may decrease transport of cephalexin despite an increase inward H+ gradient.Cephalexin uptake was linear over the concentration range when the cells were incubated at 4℃ while the uptake rate was enhanced and tended to be saturated as the cephalexin concentration increased when the cells were incubated at 37℃.The kinetic parameters for the cephalexin transport carrier were determined to be: Vmax of(22.173±1.9) nmol/min per mg protein,Km of(2.069±0.9)mol/L,the Kd was estimated to be(0.07±0.02) nmol/min per mg protein per mmol/L.Uptake of cephalexin was markedly inhibited by sodium azide(SA) and 2,4-dinitrophenol(DNP). Conclusion: Cephalexin was transported actively across Caco-2 cells,and the transport process was proton-and energy-dependent.In addition, Caco-2 cells taked up cephalexin by dipeptide transporters that closely resembled the transporters present in the intestine.Caco-2 cells represented an ideal cellular model for future studies of the dipeptide transporter.展开更多
Soluble microbial products(SMPs),dissolved organic matter excreted by activated sludge,can interact with antibiotics in wastewater and natural water bodies.Interactions between SMPs and antibiotics can influence antib...Soluble microbial products(SMPs),dissolved organic matter excreted by activated sludge,can interact with antibiotics in wastewater and natural water bodies.Interactions between SMPs and antibiotics can influence antibiotic migration,transformation,and toxicity but the mechanisms involved in such interactions are not fully understood.In this study,integrated spectroscopy approaches were used to investigate the mechanisms involved in interactions between SMPs and a representative antibiotic,trimethoprim(TMP),which has a low biodegradation rate and has been detected in wastewater.The results of liquid chromatography-organic carbon detection-organic nitrogen detection indicated that the SMPs used in the study contained 15% biopolymers and 28% humic-like substances(based on the total dissolved organic carbon concentration)so would have contained sites that could interact with TMP.A linear relationship of fluorescent intensities of tryptophan protein-like substances in SMP was observed(R^(2)>0.99),indicating that the fluorescence enhancement between SMP and TMP occurred.Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy indicated that carboxyl,carbonyl,and hydroxyl groups were the main functional groups involved in the interactions.The electrostatic andπ-πinteractions were discovered by the UV-vis spectra and 1H nuclear magnetic resonance spectra.Structural representations of the interactions between representative SMP subcomponents and TMP were calculated using density functional theory,and the results confirmed the conclusions drawn from the 1H nuclear magnetic resonance spectra.The results help characterize SMP–TMP complexes and will help understand antibiotic transformations in wastewater treatment plants and aquatic environments.展开更多
The effects of activated sintering technology of H2 atmosphere sintering on the microstructure and properties of W-15Cu alloy using ultrafine W-15Cu composite powder fabricated by spray drying calcining-continuous red...The effects of activated sintering technology of H2 atmosphere sintering on the microstructure and properties of W-15Cu alloy using ultrafine W-15Cu composite powder fabricated by spray drying calcining-continuous reduction technology were investigated.The experimental results showed that W-15Cu alloy,consolidated by activated sintering technology of H2 atmosphere sintering for 1 h at 1300 ℃,with 98.5 % relative density,transverse rupture strength 1218 MPa,Vickers hardness HV0.5 378,average grain size about 1.2 μm and thermal conductivity 192 W/m·K,was obtained.In comparison to the normal sintering process,activated sintering process to W-15Cu alloy could be achieved at lower sintering temperature.Furthermore,better properties in activated sintered compacts were obtained,and activated sintering process resulted in finer microstructure and excellent properties.展开更多
The activated sludge process （ASP） is the most generally applied biological wastewater treatment method. The ASP for the removal of organic carbon and nitrogen can be looked as the combination of eight processes. In...The activated sludge process （ASP） is the most generally applied biological wastewater treatment method. The ASP for the removal of organic carbon and nitrogen can be looked as the combination of eight processes. In order to set up an ASP model, the stoichiometric coefficients should be deduced so that the stoichiometric matrix can be presented. The important assumptions and simplifications behind the model for ASP are enumerated. Using the matrix, mass balance equation and consistent units, the stoichiometric coefficients in the eight processes are exclusively deduced one by one.展开更多
By combining sequencing batch reactor (SBR) activated sludge process and constructed wetland (CW), this study is to achieve the domestic wastewater treatment. Our purpose was to determine the optimum operating paramet...By combining sequencing batch reactor (SBR) activated sludge process and constructed wetland (CW), this study is to achieve the domestic wastewater treatment. Our purpose was to determine the optimum operating parameters of the combined process. The process involved advantages and shortages of SBR and CW. Under normal temperature, the 3rd cycle (SBR’s operation cycle is 8 h: inflow for 1 h, limited aeration for 3 h, sediment for 1 h, outflow for 1 h, and idling for 2 h; CW’s hydraulic retention time (HRT) is 24.8 h and hydraulic loading is 24.5 m3/m2 d) was the best cyclic mode. The effluents can meet the standard GB/T18921-2002: "The reuse of urban recycling water: water quality standard for scenic environment use". In the 3rd cycle, the efficiency of CW was the maximum, and energy consumption of SBR was the minimum. Under the condition of low dissolved oxygen, the removing efficiency of chemical oxygen demand (COD) and ammonia was not affected obviously. Simultaneously, nitrification and denitrification phenomena occured and phosphorus was absorbed obviously.展开更多
To resolve the technical difficulty of managing the product devdoping process,an ob-ject model for product developing process is provided by using the object-oriented methodology.In this model,the constituent objects ...To resolve the technical difficulty of managing the product devdoping process,an ob-ject model for product developing process is provided by using the object-oriented methodology.In this model,the constituent objects including activity,transition,data,partidpant,applica-tion tool and resource as well as the rela tions between them are identified and discussed in detail.According to this model,a function framework of the process managing system is also proposed.Based on the object model and the function framework,product devdoping process and productinformation flow can be efficiently managed and controlled.As a result,costly errors and dupli-cate efforts are avoided in the product developing process,which is useful for shor tening develop-ment cyde and improving product quality.展开更多
In recent decades,meromictic ponds attract the attention of researchers in different directions,because here the character of the physical,chemical and biological processes differ from those of typical mixing waters(K...In recent decades,meromictic ponds attract the attention of researchers in different directions,because here the character of the physical,chemical and biological processes differ from those of typical mixing waters(Kuznetsov,1970;Hutchinson,1969).In Transbaikalia widely distributed soda and salt lakes with different salinity.Notable among them is Lake Doroninskoye,which has a pronounced stratification for a展开更多
National logistics system in Indonesia can be categorized as inefficient logistics system due to current number of non-value added （NVA） activities. The unreliable National logistics system and the complexity of dis...National logistics system in Indonesia can be categorized as inefficient logistics system due to current number of non-value added （NVA） activities. The unreliable National logistics system and the complexity of distribution system are the big obstacles. This study aims to analyze the value and to propose recommendation for further improvement of National distribution system for imported product. This study employed convenience sampling through in-depth interview to analyze the activity in freight forwarder （FF）, distributor and retailer. To demonstrate and analyze the activity process in each party, Process Activity Mapping （PAM） was used as a tool. The study results showed that the delivery speed in Jakarta （8.4 min/km） is slower than that of Surabaya （6.6 min/km）. The government support through creating adequate infrastructure, good bureaucracy system and good collaboration directly affects the activities of FF, distributor and retailer. Improving FF performance in a timely and reliable manner is required to reduce errors that may occur. Moreover, encouraging the practice of cold chain management is also necessary in distributing the product throughout Indonesia. The pull strategy can be chosen by retailer to eliminate storage activity. Meanwhile, the use of information technology （IT） system is essential to encourage better inventory management, database management and sharing information in distributor and retailer stage.展开更多
Carbon aerogels were synthesized via ambient pressure drying process using resorcinolformaldehyde as precursor and P123 to strengthen their skeletons. CO2 activation technology was implemented to improve surface areas...Carbon aerogels were synthesized via ambient pressure drying process using resorcinolformaldehyde as precursor and P123 to strengthen their skeletons. CO2 activation technology was implemented to improve surface areas and adjust pore size distribution. The synthesis process was optimized, and the morphology, structure, adsorption properties and electrochemical behavior of different samples were characterized. The CO2-activated samples achieved a high specific capacitance of 129.2 F/g in 6 M KOH electrolytes at the current density of 1 m A/cm^2 within the voltage range of 0-0.8 V. The optimized activation temperature and duration were determined to be 950 ℃ and 4 h, respectively.展开更多
文摘In this paper, CiteSpace, a bibliometrics software, was adopted to collect research papers published on the Web of Science, which are relevant to biological model and effluent quality prediction in activated sludge process in the wastewater treatment. By the way of trend map, keyword knowledge map, and co-cited knowledge map, specific visualization analysis and identification of the authors, institutions and regions were concluded. Furthermore, the topics and hotspots of water quality prediction in activated sludge process through the literature-co-citation-based cluster analysis and literature citation burst analysis were also determined, which not only reflected the historical evolution progress to a certain extent, but also provided the direction and insight of the knowledge structure of water quality prediction and activated sludge process for future research.
基金funding support by the National Natural Science Foundation of China(Grant No.21872116 and 22075232)the Mobility Program of the Sino-German Center for Research Promotion(Grant No.M-0377)the financial support by National Natural Science Foundation of China(Grant No.21991151,21991150,22021001)。
文摘Developing highly-active,earth-abundant non-precious-metal catalysts for hydrogen evolution reaction(HER)in alkaline solution would be beneficial to sustainable energy storage.Perovskite oxides are generally regarded as low-active HER catalysts,due to their inapposite hydrogen adsorption and water dissociation.Here,we report a detailed study on perovskite LaCoO_(3)epitaxial thin films as a model catalyst to significantly enhance the HER performance via an electrochemical activation process.As a result,the overpotential for the activation films to achieve a current density of 0.36 m A/cm^(2)is 238 m V,reduced by more than 200 m V in comparison with that of original samples.Structural characterization revealed the activation process dramatically increases the concentration of oxygen vacancies(Vo)on the surface of LaCoO_(3).We established the relationship between the electronic structure induced by Vo and the enhanced HER activity.Further theoretical calculations revealed that the Vo optimizes the hydrogen adsorption and dissociation of water on the surface of LaCoO_(3)thin films,thus improving the HER catalytic activity.This work may promote a deepened understanding of perovskite oxides for HER mechanism by Vo adjusting and a new avenue for designing highly active electrochemical catalysts in alkaline solution.
文摘The microstructural properties and electrochemical performance of zinc(Zn)sacrificial anodes during strain-induced melt activation(SIMA)were investigated in this study.The samples were subjected to a compressive ratio of 20%-50% at various temperatures(425-435℃)and durations(5-30 min).Short-term electrochemical tests(anode tests)based on DNV-RP-B401 and potentiodynamic polarization tests were performed in 3.5wt%NaCl solution to evaluate the electrochemical efficiency and corrosion behavior of the samples,respectively.The electrochemical test results for the optimum sample confirmed that the corrosion current density declined by 90% and the anode efficiency slightly decreased relative to that of the raw sample.Energy-dispersive X-ray spectroscopy,scanning electron microscopy,metallographic images,and microhardness profiles showed the accumulation of alloying elements on the boundary and the conversion of uniform corrosion into localized corrosion,hence the decrease of the Zn sacrificial anode’s efficiency after the SIMA process.
基金financial supports of National Natural Science Foundation of China(22171226)Natural Science Basic Research Program of Shaanxi(2022JC-06).
文摘According to the second law of thermodynamics,spontaneous chemical processes will ultimately reach the equilibrium state with the lowest energy.However,in biological systems,there are numerous highenergy states far from equilibrium.One typical example is the transmembrane ion-concentration gradient,which plays crucial roles in maintaining homeostasis,regulating cell volume,and enabling cell signaling.Transmembrane ion-concentration gradient is achieved by an active transport process that requires the input of energy and the action of pump proteins.Replicating this process with synthetic supramolecular systems is particularly challenging,requiring both the input of energy and very specific,spatiotemporal control over ion uptake and release.In nature,pump proteins,such as protein-based ion channels,have evolved highly intricate architectures to perform this function.In contrast,Aprahamian and coworkers recently developed a much simpler smallmolecule system that functions as a molecular ion pump,utilizing light energy to pump chloride ions across a hydrophobic barrier against the concentration gradient[1].
基金the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2021D01A03)Project of Tian chi talent leader in Xinjiang Uygur Autonomous Region(2022).
文摘The utilization of biowaste to the activated carbon(AC)as electrode material is conducive to alleviating the energy crisis and promoting the high value-added.The popular KOH activation has been applied for years,but rare report clarified the difference of dry and wet activation,with which the batch producing technique could be different.Here nitrogen doped hierarchical AC was derived from wood chip by a wet or dry KOH activation.The surface area,framework structure and surface feature were characterized to reveal the effect of wet and dry activation.1.44 at%of nitrogen doped AC was made by dry KOH activation,which was higher than the AC derived from wet KOH activation with 1.36 at%of nitrogen.Their electrochemical properties were investigated in 6 mol L^(-1)of KOH,the capacitance of wAC was 401 F g^(-1)at 0.5 A g^(-1),but dAC possessed a capacitance of 215 F g^(-1).These indicated that AC obtained by using wet KOH activation displayed a potential application in energy field.
文摘Structure evolution of an Al-Zn wrought alloy in remelting processing in thestrain induced melt activated (SIMA) serai-solid procedure was observed, and effects of factors, theremelting temperature, the holding time, and the compression strain, on structures and grain sizesof the alloy were investigated. The results show that (1) the proper temperature of remelting is inthe range of 610 to 615℃; (2) the grain size in specimen with greater compression strain is smallerthan that with smaller compression strain in condition of the same remelting temperature andholding time, and the grain size in local area with great local equivalent strain is smaller thanthat with small one; (3) liquid occurs in form of cluster in matrix during remelting and itsquantity increases with remelting time increasing; liquid in specimen with great compression strainoccurs earlier than that with small one, and quantity of liquid in the center of specimen withgreater local equivalent strain is greater than that in the two ends of it; (4) distortion energyafter deforming in matrix of the alloy is the significant factor to activate melting of matrix atlocal area with great local equivalent strain.
文摘To develop technically feasible and economically favorable dynamic process control(DPC)strategies for an alternating activated sludge(AAS)system,a bench-scale continuous-flow alternating aerobic and anoxic reactor,performing short-cut nitrogen removal from real domestic wastewater was operated under different control strategies for more than five months.A fixed-time control(FTC) study showed that bending-points on pH and oxidation-reduction potential(ORP)profiles accurately coincided with the major biologic...
基金Project(2012AA06A202)supported by Hi-tech Research and Development Project of China
文摘The removal efficiencies of heavy metals(As, Cr, Cu, Ni, Pb and Zn) were investigated in the 17 operating municipal wastewater treatment plants(WWTPs) and compared with those in four main activated sludge processes. Significant differences of heavy metal removal efficiencies were observed among four activated sludge processes. The removal efficiency for As(75.5%) in the oxidation ditch(OD) process is significantly higher than that in the conventional activated sludge(CAS) process(38.6%) or sequencing batch reactor(SBR) process(51.4%). The mean removal efficiencies for Cu and Ni in the OD process are 90.5% and 46.7%, respectively, while low mean removal efficiencies are observed for Cu(69.9%) and Ni(16.5%), respectively, in the SBR process. The removal efficiencies for Cu and Ni in the OD process are significantly higher than those in the anaerobic-anoxic-oxic(A2-O) process. These results highlight the differences of removal efficiencies for heavy metals in different processes and should be considered when selecting a wastewater treatment process.
基金supported by the National Grand Water Project(No.2008ZX07423-002)the National Natural Science Foundation of China(No.50978170)the Guangdong Provincial Funding(No.2012B030800001)
文摘Two hybrid processes including ozonation-ceramic membrane-biological activated carbon （BAC） （Process A） and ceramic membrane-BAC （Process B） were compared to treat polluted raw water. The performance of hybrid processes was evaluated with the removal efficiencies of turbidity, ammonia and organic matter. The results indicated that more than 99% of particle count was removed by both hybrid processes and ozonation had no significant effect on its removal. BAC filtration greatly improved the removal of ammonia. Increasing the dissolved oxygen to 30.0 mg/L could lead to a removal of ammonia with concentrations as high as 7.80 mg/L and 8.69 mg/L for Processes A and B, respectively. The average removal efficiencies of total organic carbon and ultraviolet absorbance at 254 nm （UV254, a parameter indicating organic matter with aromatic structure） were 49% and 52% for Process A, 51% and 48% for Process B, respectively. Some organic matter was oxidized by ozone and this resulted in reduced membrane fouling and increased membrane flux by 25%-30%. However, pre-ozonation altered the components of the raw water and affected the microorganisms in the BAC, which may impact the removals of organic matter and nitrite negatively.
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(Nos.41807235,50674038).
文摘A new Mg−10%Al−1%Zn−1%Si alloy with non-dendritic microstructure was prepared by strain induced melt activation(SIMA)process.The effect of compression ratio on the evolution of semisolid microstructure of the experimental alloy was investigated.The results indicate that the average size ofα-Mg grains decreases and spheroidizing tendency becomes more obvious with the compression ratios increasing from 0 to 40%.In addition,the eutectic Mg2Si phase in the Mg−10%Al−1%Zn−1%Si alloy transforms completely from the initial fishbone shape to globular shape by SIMA process.With the increasing of compression ratio,the morphology and average size of Mg2Si phases do not change obviously.The morphology modification mechanism of Mg2Si phase in Mg−10%Al−1%Zn−1%Si alloy by SIMA process was also studied.
基金supported by the National Science Foundation of China (Grant no. 51408419)the National Key Technology Research and Development Program of China (Grant nos. 2014BAL02B02-03 and 2014BAC29B01)the Key Program for International S&T Cooperation Projects of China (Grant no. 2012DFG91380)
文摘As an important intermediate product, short-chain fatty acids（SCFAs） can be generated after hydrolysis and acidification from waste activated sludge, and then can be transformed to methane during anaerobic digestion process. In order to obtain more SCFA and methane,most studies in literatures were centered on enhancing the hydrolysis of sludge anaerobic digestion which was proved as un-efficient. Though the alkaline pretreatment in our previous study increased both the hydrolysis and acidification processes, it had a vast chemical cost which was considered uneconomical. In this paper, a low energy consumption pretreatment method, i.e. enhanced the whole three stages of the anaerobic fermentation processes at the same time, was reported, by which hydrolysis and acidification were both enhanced, and the SCFA and methane generation can be significantly improved with a small quantity of chemical input. Firstly, the effect of different pretreated temperatures and pretreatment time on sludge hydrolyzation was compared. It was found that sludge pretreated at 100°C for 60 min can achieve the maximal hydrolyzation. Further, effects of different initial p Hs on acidification of the thermal pretreated sludge were investigated and the highest SCFA was observed at initial p H 9.0with fermentation time of 6 d, the production of which was 348.63 mg COD/g VSS（6.8 times higher than the blank test） and the acetic acid was dominant acid. Then, the mechanisms for this new pretreatment significantly improving SCFA production were discussed. Finally,the effect of this low energy consumption pretreatment on methane generation was investigated.
基金The work was Supported by National Natural Science Foundation of China(30371392)
文摘Objective: To determine the active process on dipeptide transport with proton-and energy-dependence in Caco-2 cells.Methods: A human intestinal cell monolayer(Caco-2) was used as the in vitro model of human small intestine and cephalexin as the model substrate for dipeptide transporter(PepT1).Caco-2 cells grown on multiwell dishes(24 wells) and Transwell membrane filters were incubated in the culture medium. The transport and uptake experiments of cephalexin across apical membranes were then conducted with different temperature and different pH values.Uptake of cephalexin in Caco-2 cells gsown on multiple well dishes with addition of energy inhibitors(sodium azide,SA and 2,4-dinitrophenol,DNP) were then measured. Results: The accumulation of cephalexin into Caco-2 monolayers increased with the duration of culture.The uptake from the apical surface was markedly influenced by the pH of the apical medium,and the maximal uptake was achieved at pH 5.5;further acidification of the incubation medium may decrease transport of cephalexin despite an increase inward H+ gradient.Cephalexin uptake was linear over the concentration range when the cells were incubated at 4℃ while the uptake rate was enhanced and tended to be saturated as the cephalexin concentration increased when the cells were incubated at 37℃.The kinetic parameters for the cephalexin transport carrier were determined to be: Vmax of(22.173±1.9) nmol/min per mg protein,Km of(2.069±0.9)mol/L,the Kd was estimated to be(0.07±0.02) nmol/min per mg protein per mmol/L.Uptake of cephalexin was markedly inhibited by sodium azide(SA) and 2,4-dinitrophenol(DNP). Conclusion: Cephalexin was transported actively across Caco-2 cells,and the transport process was proton-and energy-dependent.In addition, Caco-2 cells taked up cephalexin by dipeptide transporters that closely resembled the transporters present in the intestine.Caco-2 cells represented an ideal cellular model for future studies of the dipeptide transporter.
基金supported by the National Natural Science Foundation of China (Nos. 51878244 and 52170032)the the Fundamental Research Funds for the Central Universities (No. B200202101)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), China
文摘Soluble microbial products(SMPs),dissolved organic matter excreted by activated sludge,can interact with antibiotics in wastewater and natural water bodies.Interactions between SMPs and antibiotics can influence antibiotic migration,transformation,and toxicity but the mechanisms involved in such interactions are not fully understood.In this study,integrated spectroscopy approaches were used to investigate the mechanisms involved in interactions between SMPs and a representative antibiotic,trimethoprim(TMP),which has a low biodegradation rate and has been detected in wastewater.The results of liquid chromatography-organic carbon detection-organic nitrogen detection indicated that the SMPs used in the study contained 15% biopolymers and 28% humic-like substances(based on the total dissolved organic carbon concentration)so would have contained sites that could interact with TMP.A linear relationship of fluorescent intensities of tryptophan protein-like substances in SMP was observed(R^(2)>0.99),indicating that the fluorescence enhancement between SMP and TMP occurred.Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy indicated that carboxyl,carbonyl,and hydroxyl groups were the main functional groups involved in the interactions.The electrostatic andπ-πinteractions were discovered by the UV-vis spectra and 1H nuclear magnetic resonance spectra.Structural representations of the interactions between representative SMP subcomponents and TMP were calculated using density functional theory,and the results confirmed the conclusions drawn from the 1H nuclear magnetic resonance spectra.The results help characterize SMP–TMP complexes and will help understand antibiotic transformations in wastewater treatment plants and aquatic environments.
基金Funded by the Project for Science and Technology Plan of Wuhan City(200910321092)the Fundamental Research Funds for the Central Universities(2010-Ⅱ-020)
文摘The effects of activated sintering technology of H2 atmosphere sintering on the microstructure and properties of W-15Cu alloy using ultrafine W-15Cu composite powder fabricated by spray drying calcining-continuous reduction technology were investigated.The experimental results showed that W-15Cu alloy,consolidated by activated sintering technology of H2 atmosphere sintering for 1 h at 1300 ℃,with 98.5 % relative density,transverse rupture strength 1218 MPa,Vickers hardness HV0.5 378,average grain size about 1.2 μm and thermal conductivity 192 W/m·K,was obtained.In comparison to the normal sintering process,activated sintering process to W-15Cu alloy could be achieved at lower sintering temperature.Furthermore,better properties in activated sintered compacts were obtained,and activated sintering process resulted in finer microstructure and excellent properties.
基金supported by the Special Foundation of Shanghai Municipal Education Commission (Grant No.06AZ057)
文摘The activated sludge process （ASP） is the most generally applied biological wastewater treatment method. The ASP for the removal of organic carbon and nitrogen can be looked as the combination of eight processes. In order to set up an ASP model, the stoichiometric coefficients should be deduced so that the stoichiometric matrix can be presented. The important assumptions and simplifications behind the model for ASP are enumerated. Using the matrix, mass balance equation and consistent units, the stoichiometric coefficients in the eight processes are exclusively deduced one by one.
基金Funded by Sustainable Water Management Improves Tomorrow’s City’s Health (SWITCH018530)
文摘By combining sequencing batch reactor (SBR) activated sludge process and constructed wetland (CW), this study is to achieve the domestic wastewater treatment. Our purpose was to determine the optimum operating parameters of the combined process. The process involved advantages and shortages of SBR and CW. Under normal temperature, the 3rd cycle (SBR’s operation cycle is 8 h: inflow for 1 h, limited aeration for 3 h, sediment for 1 h, outflow for 1 h, and idling for 2 h; CW’s hydraulic retention time (HRT) is 24.8 h and hydraulic loading is 24.5 m3/m2 d) was the best cyclic mode. The effluents can meet the standard GB/T18921-2002: "The reuse of urban recycling water: water quality standard for scenic environment use". In the 3rd cycle, the efficiency of CW was the maximum, and energy consumption of SBR was the minimum. Under the condition of low dissolved oxygen, the removing efficiency of chemical oxygen demand (COD) and ammonia was not affected obviously. Simultaneously, nitrification and denitrification phenomena occured and phosphorus was absorbed obviously.
文摘To resolve the technical difficulty of managing the product devdoping process,an ob-ject model for product developing process is provided by using the object-oriented methodology.In this model,the constituent objects including activity,transition,data,partidpant,applica-tion tool and resource as well as the rela tions between them are identified and discussed in detail.According to this model,a function framework of the process managing system is also proposed.Based on the object model and the function framework,product devdoping process and productinformation flow can be efficiently managed and controlled.As a result,costly errors and dupli-cate efforts are avoided in the product developing process,which is useful for shor tening develop-ment cyde and improving product quality.
基金supported by Integration projects of the Presidium of SB RAS№5,56,94
文摘In recent decades,meromictic ponds attract the attention of researchers in different directions,because here the character of the physical,chemical and biological processes differ from those of typical mixing waters(Kuznetsov,1970;Hutchinson,1969).In Transbaikalia widely distributed soda and salt lakes with different salinity.Notable among them is Lake Doroninskoye,which has a pronounced stratification for a
文摘National logistics system in Indonesia can be categorized as inefficient logistics system due to current number of non-value added （NVA） activities. The unreliable National logistics system and the complexity of distribution system are the big obstacles. This study aims to analyze the value and to propose recommendation for further improvement of National distribution system for imported product. This study employed convenience sampling through in-depth interview to analyze the activity in freight forwarder （FF）, distributor and retailer. To demonstrate and analyze the activity process in each party, Process Activity Mapping （PAM） was used as a tool. The study results showed that the delivery speed in Jakarta （8.4 min/km） is slower than that of Surabaya （6.6 min/km）. The government support through creating adequate infrastructure, good bureaucracy system and good collaboration directly affects the activities of FF, distributor and retailer. Improving FF performance in a timely and reliable manner is required to reduce errors that may occur. Moreover, encouraging the practice of cold chain management is also necessary in distributing the product throughout Indonesia. The pull strategy can be chosen by retailer to eliminate storage activity. Meanwhile, the use of information technology （IT） system is essential to encourage better inventory management, database management and sharing information in distributor and retailer stage.
基金Funded by the National High Technology Research and Development Program(863 Program)(No.2013AA050905),China Academy of Engineering Physics,Mianyang,China
文摘Carbon aerogels were synthesized via ambient pressure drying process using resorcinolformaldehyde as precursor and P123 to strengthen their skeletons. CO2 activation technology was implemented to improve surface areas and adjust pore size distribution. The synthesis process was optimized, and the morphology, structure, adsorption properties and electrochemical behavior of different samples were characterized. The CO2-activated samples achieved a high specific capacitance of 129.2 F/g in 6 M KOH electrolytes at the current density of 1 m A/cm^2 within the voltage range of 0-0.8 V. The optimized activation temperature and duration were determined to be 950 ℃ and 4 h, respectively.
