BACKGROUND Adipose-derived stem cells(ADSCs)and the stromal vascular fraction(SVF)have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions.Traditional enzy...BACKGROUND Adipose-derived stem cells(ADSCs)and the stromal vascular fraction(SVF)have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions.Traditional enzymatic methods for isolating these cells face challenges such as high costs,lengthy processing time,and regulatory complexities.AIM This systematic review aimed to assess the efficacy and practicality of nonenzymatic,mechanical methods for isolating SVF and ADSCs,comparing these to conventional enzymatic approaches.METHODS Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across multiple databases.Studies were selected based on inclusion criteria focused on non-enzymatic isolation methods for SVF and ADSCs from adipose tissue.The risk of bias was assessed,and a qualitative synthesis of findings was performed due to the methodological heterogeneity of the included studies.RESULTS Nineteen studies met the inclusion criteria,highlighting various mechanical techniques such as centrifugation,vortexing,and ultrasonic cavitation.The review identified significant variability in cell yield and viability,and the integrity of isolated cells across different non-enzymatic methods compared to enzymatic procedures.Despite some advantages of mechanical methods,including reduced processing time and avoidance of enzymatic reagents,the evidence suggests a need for optimization to match the cell quality and therapeutic efficacy achievable with enzymatic isolation.CONCLUSION Non-enzymatic,mechanical methods offer a promising alternative to enzymatic isolation of SVF and ADSCs,potentially simplifying the isolation process and reducing regulatory hurdles.However,further research is necessary to standardize these techniques and ensure consistent,high-quality cell yields for clinical applications.The development of efficient,safe,and reproducible non-enzymatic isolation methods could significantly advance the field of regenerative medicine.展开更多
Reversed-phase paper chromatography technique is used for study on the extraction mechanism and sep- aration of rare earth elements.As the stationary phase,chromatographic paper strips are impregnated with a solution ...Reversed-phase paper chromatography technique is used for study on the extraction mechanism and sep- aration of rare earth elements.As the stationary phase,chromatographic paper strips are impregnated with a solution of monomyristyl phosphoric acid (MPA) in chloroform.Mineral acids are used as developers. The effect of concentration of acids and/or salts upon R_f has been investigated.According to the re- sults of R_f values for a given rare earth element in various acids,the order of extraction ability is HCl>HNO_3>H_2SO_4.A tetrad effect is clearly observed.for the R_f value of rare earth elements.The effects of other parameters on the R_f value,such as the quantities of extractant retained by the paper and the temperature are also examined.Based on the determination of the molar ratio of MPA to rare earth elements and the number of H^+ ions released in extraction reaction,a reasonable mechanism is proposed.The mutual separation of heavy rare earth elements will be better than that of the light rare earth group because of the larger separation coefficient of the former.A mixture of Ho-Er-Tm-Lu is successfully separated by the present method.展开更多
Anaerobic digestion(AD)as a waste management method has the potential to reduce greenhouse gas emissions while pro-ducing renewable energy,making it a viable option for managing the organic fraction of municipal solid...Anaerobic digestion(AD)as a waste management method has the potential to reduce greenhouse gas emissions while pro-ducing renewable energy,making it a viable option for managing the organic fraction of municipal solid waste(OFMSW).OFMSW characteristics can vary depending on factors such as waste source,composition and separation units.The charac-teristics of OFMSW are critical for analyzing and monitoring the AD process to optimize biogas production.In this study,the waste composition and physicochemical characteristics of the mechanically separated OFMSW(ms-OFMSW)were determined at a full-scale AD plant in Turkiye.The ms-OFMSW samples were collected monthly after mechanical separation and were subsequently sent to the anaerobic digester.The composition and physicochemical characteristics of the samples were determined by manual sorting.The results showed that the majority of the ms-OFMSW(76.45%±1.71%)was organic,while 8.99%±1.56%was recyclable and 14.56%±1.69%was non-recyclable.Loss of environmental benefits for the recyclable materials was determined using a free online tool provided by Environmental Protection Agency.Metals(399.7 GJ)and plas-tics(403.7 GJ)both saved nearly the same amount of energy while metals saved the most water(421.8 m3),with the greatest positive impact.Greenhouse benefits ranged from 3 tons to 40 tons of carbon dioxide equivalent for each waste stream.These findings suggest that efficient pre-separation units can improve the anaerobic digestibility of OFMSW,while also providing greater environmental benefits by preventing recyclable waste from the anaerobic digester.In addition to encouraging source separation applications,this study demonstrates the need for improved technologies to separate OFMSW from mixed MSW.展开更多
Covalent organic frameworks(COFs)are a new kind of crystalline porous materials composed of organic molecules connected by covalent bonds,processes the characteristics of low density,large specific surface area,adjust...Covalent organic frameworks(COFs)are a new kind of crystalline porous materials composed of organic molecules connected by covalent bonds,processes the characteristics of low density,large specific surface area,adjustable pore size and structure,and easy to functionalize,which have been widely used in the field of membrane separation technology.Recently,there are more and more researches focusing on the preparation methods,separation application,and mechanism of COF membranes,which need to be further summarized and compared.In this review,we primarily summarized several conventional preparation methods,such as two-phase interfacial polymerization,in-situ growth on substrate,unidirectional diffusion method,layer-by-layer assembly method,mixed matrix membranes,and so on.The advantages and disadvantages of each method are briefly summarized.The application potential of COF membrane in liquid separation are introduced from four aspects:dyeing wastewater treatment,heavy metal removal,seawater desalination and oil-water separation.Then,the mechanisms including pore structure,hydrophilic/hydrophobic,electrostatic repulsion/attraction and Donnan effect are introduced.For the efficient removal of different kind of pollutions,researchers can select different ligands to construct membranes with specific pore size,hydrophily,salt or organic rejection ability and functional group.The ideas for the design and preparation of COF membranes are introduced.Finally,the future direction and challenges of the next generation of COF membranes in the field of separation are prospected.展开更多
With the global warming of concern,the secondary aluminum stream is becoming an even more important component of aluminum production and is attractive because of its economic and environmental benefits.In this work,re...With the global warming of concern,the secondary aluminum stream is becoming an even more important component of aluminum production and is attractive because of its economic and environmental benefits.In this work,recycling of automotive aluminum is reviewed to highlight environmental benefits of aluminum recycling,use of aluminum alloys in automotive applications,automotive recycling process,and new technologies in aluminum scrap process.Literature survey shows that newly developed techniques such as laser induced breakdown spectroscopy(LIBS) and solid state recycling provide promising alternatives in aluminum scrap process.Compared with conventional remelting and subsequent refinement,solid state recycling utilizing compression and extrusion at room or moderate temperature can result in significant energy savings and higher metal yield.展开更多
The ionic liquid(IL)1-ethyl-3-methylimidazolium dicyanamide([EMIM][DCA])was selected as an appropriate entrainer for the extractive distillation of the methanol-ethanol-water mixture.The COSMO-RS model was applied to ...The ionic liquid(IL)1-ethyl-3-methylimidazolium dicyanamide([EMIM][DCA])was selected as an appropriate entrainer for the extractive distillation of the methanol-ethanol-water mixture.The COSMO-RS model was applied to screen out the appropriate solvents considering selectivity and solvent capacity together.Isobaric vapor-liquid equilibrium(VLE)experiments for the two systems of methanol-water and ethanol-water with different amounts of[EMIM][DCA]added were conducted at 101.3 kPa.The experimental data showed that[EMIM][DCA]exhibits an obvious salting effect for the methanol(or ethanol)-water mixture and eliminates the azeotropic point of ethanol-water.Moreover,the predicted values by UNIFAC-Lei model coincide well with experimental data.The separation mechanism was further explained in combination with surface charge density distribution(σ-profiles),excess enthalpy(HE),and binding energy.In addition,the flow charts were designed to evaluate the improvement of energy consumption with[EMIM][DCA]as the entrainer when compared to ethylene glycol(EG).The simulation results demonstrated that[EMIM][DCA]is more energy efficient than EG.展开更多
Ultra-high purity Yb_(2)O_(3) is the critical material of many high-tech materials such as laser glass and fiber,in which impurities seriously affect the laser color quality,intensity and power.In order to reduce the ...Ultra-high purity Yb_(2)O_(3) is the critical material of many high-tech materials such as laser glass and fiber,in which impurities seriously affect the laser color quality,intensity and power.In order to reduce the influence of impurities on the properties of laser materials,the purification process of Yb_(2)O_(3) was studied by comparing two kinds of resins(RT-1 and RS-1)using improved ion-exchange chromatography(IEC)method.In this study,through the synergistic improvement of resin structure and eluting system,the environmental pollution caused by ammonia water in the traditional IEC method was reduced,and the requirements of high temperature and pressure were cut.The ion exchange behavior and impurity removal mechanism in the resin column during the loading and eluting process were compared and analyzed.The experimental results show that RS-1 resin is all superior to RT-1resin in elements selectivity,ion exchange capacity and impurities removal rate.After separation and purification by IEC with RS-1 resin,the total removal rate of rare earth impurities was 77.59%and that of non-rare earth impurities was 95.86%when Yb recovery was more than 70%,both higher than that of RT-1 resin(73.26%and 83.18%).This indicates that the improved IEC method is very effective in separating and removing different metal impurities from Yb_(2)O_(3).The pilot test results of IEC method separating and purifying Yb_(2)O_(3) with RS-1 resin show that the purity of Yb_(2)O_(3) can be increased from 99.9929%to 99.9997%by IEC method.It has exhibited huge potential of preparing ultra-high purity Yb_(2)O_(3),especially the deep removal of non-rare earth impurities.展开更多
Photocatalysis is a green and environmentally-friendly process that utilizes the ubiquitous intermittent sunlight.To date,an emerging S-scheme heterojunction across the intimately coupled heterojunction materials is p...Photocatalysis is a green and environmentally-friendly process that utilizes the ubiquitous intermittent sunlight.To date,an emerging S-scheme heterojunction across the intimately coupled heterojunction materials is proposed to surpass the efficiency of conventional Ⅱ-type and Z-type photocatalysis.Further-more,S-scheme heterojunction photocatalysts with greatly improved photocatalytic performance have gained significant attention due to their fast charge carriers separation along with strong redox ability and stability,since its proposal in 2019.Herein,a timely and comprehensive review is highly desired to cover the state-of-the-art advances.Driven by this idea,the review conveys the recent progress and provides new insights into further developments.Unlike the conventional method,in this review,we im-plement a quantification model to outline current trends in S-scheme heterojunctions research as well as their correlations.The overview begins with the fundamentals of four basic photocatalytic mechanisms,followed by its design principles.Afterward,diverse characterization techniques used in the S-scheme heterojunctions are systematically summarized along with the modification strategies to boost photocat-alytic performances.Additionally,the internal reaction mechanism and emerging applications have been reviewed,including water conversion,CO_(2) remediation,wastewater treatment,H_(2)0_(2) production,N_(2) fix-ation,etc.To sum up the review,we present several current challenges and future prospects of the S-scheme heterojunctions photocatalysts,aiming to provide indispensable platforms for the future smart design of photocatalysts.展开更多
The traditional separation of bicyclic and tricyclic aromatics from coal tar involves complicated multi-steps and consumes significantly more energy.Previous work accomplished the separation between anthracene-phenant...The traditional separation of bicyclic and tricyclic aromatics from coal tar involves complicated multi-steps and consumes significantly more energy.Previous work accomplished the separation between anthracene-phenanthrene isomers using electrostatic interaction,but for the separation between bicyclic and tricyclic aromatics,electrostatic interactions are difficult to produce a recognizable effect.Naphthalene-based solvents,named as naphthaleneacetamide,naphthaleneethanol,naphthalenemethanol,naphthol,naphthylacetic acid,naphthylacetonitrile,and naphthylamine,respectively,were used for the efficient separation of naphthalene and phenanthrene via dispersion interaction.Results showed that the pre-studied structural parameters are the key factors in selecting an efficient solvent.And the substituents on the intermolecular interactions involved in the separation processes had an important impact,which were evaluated.Naphthalenemethanol exhibited a superior performance with a purity of 96.3 wt%naphthalene products because its electron-donating substituent enables the selective recognition of naphthalene via the dispersion interaction.The used naphthalene-based solvents can be regenerated and recycled via back extraction with a purity of over 90 wt%naphthalene products,suggesting solvent structural stability during the regeneration processes.Notably,the naphthalene-based solvents also demonstrated better separation performance for polycyclic aromatics from coal tar with a purity of over 80 wt%for bicyclic aromatics.This study would enhance the utilization of coal tar as a valuable source of polycyclic aromatics besides broadening the knowledge for applying non-bonded interaction in the separation of polycyclic aromatics technologies.展开更多
A spacecraft＇s separation parameters directly affect its flying trace. If the parameters exceed their limits, it will be difficult to adjust the flying attitude of the spacecraft, and the spacescraft may go off-track...A spacecraft＇s separation parameters directly affect its flying trace. If the parameters exceed their limits, it will be difficult to adjust the flying attitude of the spacecraft, and the spacescraft may go off-track or crash. In this paper, we present a composite optimization method, which combines angular velocities with external moments for separation parameters of large-eccentricity pico-satellites. By changing the positions of elastic launch devices, the method effectively controls the popping process under the condition of less change in the separation mechanism. Finally, the reasons for deviation of angular velocities and unreliable optimization results are presented and analyzed. This optimization method is proved through a ground test which offsets the gravity. Simulation and test results show that the optimization method can effectively optimize the separation parameters of large-eccentricity pico-satellites. The proposed method adapts particularly to the fixed and non-stable status elastic parameters, the distribution of all kinds of elastic devices, and large-eccentricity spacecrafts for which attitude corrections are difficult. It is gen- erally applicable and easy to operate in practical applications.展开更多
In this paper,the concept of reversed-or normal-phase chiral stationary phase liquid chromatography has been put forward according to the polar strength of mobile and stationary phases. The statistical model developed...In this paper,the concept of reversed-or normal-phase chiral stationary phase liquid chromatography has been put forward according to the polar strength of mobile and stationary phases. The statistical model developed in HPLC has been used to investigate the separation mechanism of D-and L-enantiomer in chiral stationary phase liquid chromatography.It has been observed that the variation of capacity factor of enantiomers with mobile phase composition in both reversed-phase and normal-phase chiral stationary phase liquid chromatography can be described by the fundamental elution equation lnk'=a+blnC_b+cC_b.The effect of mobile phase composition on the selec- tivity of enantiomers D and L in normal-phase chiral stationary phase liquid chromatography cam be described by the equation lnα=⊿a+⊿blnC_b,but in reversed-phase chiral stationary phase liquid chromatography the selectivity is almost independant of the mobile phase composition.展开更多
Graphene oxide(GO),a derivative of graphene,is a novel carbon material that has attracted a lot of attention in the field of membrane materials as its ability to achieve layer-by-layer stacking and the formation of na...Graphene oxide(GO),a derivative of graphene,is a novel carbon material that has attracted a lot of attention in the field of membrane materials as its ability to achieve layer-by-layer stacking and the formation of nanochannels between the lamellae makes it excellent for selective separation of substances.In this paper,the separation mechanism of the GO membrane is summarized.According to the different separation substances,the separation mechanism of graphene oxide membrane is reviewed from two aspects of metal ions and organic pollutants.Next,the preparation methods of graphene oxide membranes is introduced,such as spin-coating,vacuum filtration,dip-coating,spraying,and layer-by-layer self-assembly,followed by a review on the structural regulation of GO.Finally,this paper concludes with an overview of the potential development prospects and challenges of GO membranes.展开更多
文摘BACKGROUND Adipose-derived stem cells(ADSCs)and the stromal vascular fraction(SVF)have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions.Traditional enzymatic methods for isolating these cells face challenges such as high costs,lengthy processing time,and regulatory complexities.AIM This systematic review aimed to assess the efficacy and practicality of nonenzymatic,mechanical methods for isolating SVF and ADSCs,comparing these to conventional enzymatic approaches.METHODS Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines,a comprehensive literature search was conducted across multiple databases.Studies were selected based on inclusion criteria focused on non-enzymatic isolation methods for SVF and ADSCs from adipose tissue.The risk of bias was assessed,and a qualitative synthesis of findings was performed due to the methodological heterogeneity of the included studies.RESULTS Nineteen studies met the inclusion criteria,highlighting various mechanical techniques such as centrifugation,vortexing,and ultrasonic cavitation.The review identified significant variability in cell yield and viability,and the integrity of isolated cells across different non-enzymatic methods compared to enzymatic procedures.Despite some advantages of mechanical methods,including reduced processing time and avoidance of enzymatic reagents,the evidence suggests a need for optimization to match the cell quality and therapeutic efficacy achievable with enzymatic isolation.CONCLUSION Non-enzymatic,mechanical methods offer a promising alternative to enzymatic isolation of SVF and ADSCs,potentially simplifying the isolation process and reducing regulatory hurdles.However,further research is necessary to standardize these techniques and ensure consistent,high-quality cell yields for clinical applications.The development of efficient,safe,and reproducible non-enzymatic isolation methods could significantly advance the field of regenerative medicine.
文摘Reversed-phase paper chromatography technique is used for study on the extraction mechanism and sep- aration of rare earth elements.As the stationary phase,chromatographic paper strips are impregnated with a solution of monomyristyl phosphoric acid (MPA) in chloroform.Mineral acids are used as developers. The effect of concentration of acids and/or salts upon R_f has been investigated.According to the re- sults of R_f values for a given rare earth element in various acids,the order of extraction ability is HCl>HNO_3>H_2SO_4.A tetrad effect is clearly observed.for the R_f value of rare earth elements.The effects of other parameters on the R_f value,such as the quantities of extractant retained by the paper and the temperature are also examined.Based on the determination of the molar ratio of MPA to rare earth elements and the number of H^+ ions released in extraction reaction,a reasonable mechanism is proposed.The mutual separation of heavy rare earth elements will be better than that of the light rare earth group because of the larger separation coefficient of the former.A mixture of Ho-Er-Tm-Lu is successfully separated by the present method.
基金the Scientific Research Project supported by The Istanbul Technical University,Turkiye(Yagmur Kabakci,Project No.MDK-2019-42183)The authors gratefully acknowledge to Duzce Solid Waste Association,Project No.5218B04.
文摘Anaerobic digestion(AD)as a waste management method has the potential to reduce greenhouse gas emissions while pro-ducing renewable energy,making it a viable option for managing the organic fraction of municipal solid waste(OFMSW).OFMSW characteristics can vary depending on factors such as waste source,composition and separation units.The charac-teristics of OFMSW are critical for analyzing and monitoring the AD process to optimize biogas production.In this study,the waste composition and physicochemical characteristics of the mechanically separated OFMSW(ms-OFMSW)were determined at a full-scale AD plant in Turkiye.The ms-OFMSW samples were collected monthly after mechanical separation and were subsequently sent to the anaerobic digester.The composition and physicochemical characteristics of the samples were determined by manual sorting.The results showed that the majority of the ms-OFMSW(76.45%±1.71%)was organic,while 8.99%±1.56%was recyclable and 14.56%±1.69%was non-recyclable.Loss of environmental benefits for the recyclable materials was determined using a free online tool provided by Environmental Protection Agency.Metals(399.7 GJ)and plas-tics(403.7 GJ)both saved nearly the same amount of energy while metals saved the most water(421.8 m3),with the greatest positive impact.Greenhouse benefits ranged from 3 tons to 40 tons of carbon dioxide equivalent for each waste stream.These findings suggest that efficient pre-separation units can improve the anaerobic digestibility of OFMSW,while also providing greater environmental benefits by preventing recyclable waste from the anaerobic digester.In addition to encouraging source separation applications,this study demonstrates the need for improved technologies to separate OFMSW from mixed MSW.
基金funding support from the National Science Foundation of China(Nos.22276054,U2167218,22006036)the Beijing Outstanding Young Scientist Program(HY,ZC,XW)。
文摘Covalent organic frameworks(COFs)are a new kind of crystalline porous materials composed of organic molecules connected by covalent bonds,processes the characteristics of low density,large specific surface area,adjustable pore size and structure,and easy to functionalize,which have been widely used in the field of membrane separation technology.Recently,there are more and more researches focusing on the preparation methods,separation application,and mechanism of COF membranes,which need to be further summarized and compared.In this review,we primarily summarized several conventional preparation methods,such as two-phase interfacial polymerization,in-situ growth on substrate,unidirectional diffusion method,layer-by-layer assembly method,mixed matrix membranes,and so on.The advantages and disadvantages of each method are briefly summarized.The application potential of COF membrane in liquid separation are introduced from four aspects:dyeing wastewater treatment,heavy metal removal,seawater desalination and oil-water separation.Then,the mechanisms including pore structure,hydrophilic/hydrophobic,electrostatic repulsion/attraction and Donnan effect are introduced.For the efficient removal of different kind of pollutions,researchers can select different ligands to construct membranes with specific pore size,hydrophily,salt or organic rejection ability and functional group.The ideas for the design and preparation of COF membranes are introduced.Finally,the future direction and challenges of the next generation of COF membranes in the field of separation are prospected.
基金Project(FRINAT) supported by the Research Council of Norway (RCN)
文摘With the global warming of concern,the secondary aluminum stream is becoming an even more important component of aluminum production and is attractive because of its economic and environmental benefits.In this work,recycling of automotive aluminum is reviewed to highlight environmental benefits of aluminum recycling,use of aluminum alloys in automotive applications,automotive recycling process,and new technologies in aluminum scrap process.Literature survey shows that newly developed techniques such as laser induced breakdown spectroscopy(LIBS) and solid state recycling provide promising alternatives in aluminum scrap process.Compared with conventional remelting and subsequent refinement,solid state recycling utilizing compression and extrusion at room or moderate temperature can result in significant energy savings and higher metal yield.
基金financially supported by the National Key Research and Development Program of China(no.2018YFB0604702)
文摘The ionic liquid(IL)1-ethyl-3-methylimidazolium dicyanamide([EMIM][DCA])was selected as an appropriate entrainer for the extractive distillation of the methanol-ethanol-water mixture.The COSMO-RS model was applied to screen out the appropriate solvents considering selectivity and solvent capacity together.Isobaric vapor-liquid equilibrium(VLE)experiments for the two systems of methanol-water and ethanol-water with different amounts of[EMIM][DCA]added were conducted at 101.3 kPa.The experimental data showed that[EMIM][DCA]exhibits an obvious salting effect for the methanol(or ethanol)-water mixture and eliminates the azeotropic point of ethanol-water.Moreover,the predicted values by UNIFAC-Lei model coincide well with experimental data.The separation mechanism was further explained in combination with surface charge density distribution(σ-profiles),excess enthalpy(HE),and binding energy.In addition,the flow charts were designed to evaluate the improvement of energy consumption with[EMIM][DCA]as the entrainer when compared to ethylene glycol(EG).The simulation results demonstrated that[EMIM][DCA]is more energy efficient than EG.
基金financially supported by the National Key R&D Program of China(No.2020YFC1909004)China Postdoctoral Science Foundation(Nos.2020M680615 and 2021T140581)the Youth Fund Project of GRINM。
文摘Ultra-high purity Yb_(2)O_(3) is the critical material of many high-tech materials such as laser glass and fiber,in which impurities seriously affect the laser color quality,intensity and power.In order to reduce the influence of impurities on the properties of laser materials,the purification process of Yb_(2)O_(3) was studied by comparing two kinds of resins(RT-1 and RS-1)using improved ion-exchange chromatography(IEC)method.In this study,through the synergistic improvement of resin structure and eluting system,the environmental pollution caused by ammonia water in the traditional IEC method was reduced,and the requirements of high temperature and pressure were cut.The ion exchange behavior and impurity removal mechanism in the resin column during the loading and eluting process were compared and analyzed.The experimental results show that RS-1 resin is all superior to RT-1resin in elements selectivity,ion exchange capacity and impurities removal rate.After separation and purification by IEC with RS-1 resin,the total removal rate of rare earth impurities was 77.59%and that of non-rare earth impurities was 95.86%when Yb recovery was more than 70%,both higher than that of RT-1 resin(73.26%and 83.18%).This indicates that the improved IEC method is very effective in separating and removing different metal impurities from Yb_(2)O_(3).The pilot test results of IEC method separating and purifying Yb_(2)O_(3) with RS-1 resin show that the purity of Yb_(2)O_(3) can be increased from 99.9929%to 99.9997%by IEC method.It has exhibited huge potential of preparing ultra-high purity Yb_(2)O_(3),especially the deep removal of non-rare earth impurities.
基金National Natural Science Foundation of China(Grant No.62004143)Key R&D Program of Hubei Province(Grant No.2022BAA084).
文摘Photocatalysis is a green and environmentally-friendly process that utilizes the ubiquitous intermittent sunlight.To date,an emerging S-scheme heterojunction across the intimately coupled heterojunction materials is proposed to surpass the efficiency of conventional Ⅱ-type and Z-type photocatalysis.Further-more,S-scheme heterojunction photocatalysts with greatly improved photocatalytic performance have gained significant attention due to their fast charge carriers separation along with strong redox ability and stability,since its proposal in 2019.Herein,a timely and comprehensive review is highly desired to cover the state-of-the-art advances.Driven by this idea,the review conveys the recent progress and provides new insights into further developments.Unlike the conventional method,in this review,we im-plement a quantification model to outline current trends in S-scheme heterojunctions research as well as their correlations.The overview begins with the fundamentals of four basic photocatalytic mechanisms,followed by its design principles.Afterward,diverse characterization techniques used in the S-scheme heterojunctions are systematically summarized along with the modification strategies to boost photocat-alytic performances.Additionally,the internal reaction mechanism and emerging applications have been reviewed,including water conversion,CO_(2) remediation,wastewater treatment,H_(2)0_(2) production,N_(2) fix-ation,etc.To sum up the review,we present several current challenges and future prospects of the S-scheme heterojunctions photocatalysts,aiming to provide indispensable platforms for the future smart design of photocatalysts.
基金financial support provided by the National Natural Science Foundation of China(Grant No.22038008)the China Shenhua Coal-to-Liquids Chemical Co.,Ltd.Science and Technology Innovation Project(Grant No.MZYHG-2021-01).
文摘The traditional separation of bicyclic and tricyclic aromatics from coal tar involves complicated multi-steps and consumes significantly more energy.Previous work accomplished the separation between anthracene-phenanthrene isomers using electrostatic interaction,but for the separation between bicyclic and tricyclic aromatics,electrostatic interactions are difficult to produce a recognizable effect.Naphthalene-based solvents,named as naphthaleneacetamide,naphthaleneethanol,naphthalenemethanol,naphthol,naphthylacetic acid,naphthylacetonitrile,and naphthylamine,respectively,were used for the efficient separation of naphthalene and phenanthrene via dispersion interaction.Results showed that the pre-studied structural parameters are the key factors in selecting an efficient solvent.And the substituents on the intermolecular interactions involved in the separation processes had an important impact,which were evaluated.Naphthalenemethanol exhibited a superior performance with a purity of 96.3 wt%naphthalene products because its electron-donating substituent enables the selective recognition of naphthalene via the dispersion interaction.The used naphthalene-based solvents can be regenerated and recycled via back extraction with a purity of over 90 wt%naphthalene products,suggesting solvent structural stability during the regeneration processes.Notably,the naphthalene-based solvents also demonstrated better separation performance for polycyclic aromatics from coal tar with a purity of over 80 wt%for bicyclic aromatics.This study would enhance the utilization of coal tar as a valuable source of polycyclic aromatics besides broadening the knowledge for applying non-bonded interaction in the separation of polycyclic aromatics technologies.
基金Project supported by the National Natural Science Foundation of China(No.61525403)
文摘A spacecraft＇s separation parameters directly affect its flying trace. If the parameters exceed their limits, it will be difficult to adjust the flying attitude of the spacecraft, and the spacescraft may go off-track or crash. In this paper, we present a composite optimization method, which combines angular velocities with external moments for separation parameters of large-eccentricity pico-satellites. By changing the positions of elastic launch devices, the method effectively controls the popping process under the condition of less change in the separation mechanism. Finally, the reasons for deviation of angular velocities and unreliable optimization results are presented and analyzed. This optimization method is proved through a ground test which offsets the gravity. Simulation and test results show that the optimization method can effectively optimize the separation parameters of large-eccentricity pico-satellites. The proposed method adapts particularly to the fixed and non-stable status elastic parameters, the distribution of all kinds of elastic devices, and large-eccentricity spacecrafts for which attitude corrections are difficult. It is gen- erally applicable and easy to operate in practical applications.
基金This work was supported by the National Natural Science Foundation of China.
文摘In this paper,the concept of reversed-or normal-phase chiral stationary phase liquid chromatography has been put forward according to the polar strength of mobile and stationary phases. The statistical model developed in HPLC has been used to investigate the separation mechanism of D-and L-enantiomer in chiral stationary phase liquid chromatography.It has been observed that the variation of capacity factor of enantiomers with mobile phase composition in both reversed-phase and normal-phase chiral stationary phase liquid chromatography can be described by the fundamental elution equation lnk'=a+blnC_b+cC_b.The effect of mobile phase composition on the selec- tivity of enantiomers D and L in normal-phase chiral stationary phase liquid chromatography cam be described by the equation lnα=⊿a+⊿blnC_b,but in reversed-phase chiral stationary phase liquid chromatography the selectivity is almost independant of the mobile phase composition.
基金Y.X.W.,L.J.H.and J.G.T.acknowledge the National Natural Scientific Foundation of China(Nos.51878361 and 52070104)the Natural Scientific Foundation of Shandong Province(No.ZR2019MEM048)+2 种基金the State Key Project of International Cooperation Research(No.2016YFE01108002017YFE0108300)the National Program for Introducing Talents of Discipline to Universities(“111”plan)the 1st Class Discipline Program of Materials Science of Shandong Province,and the DoubleHundred Foreign Expert Program of Shandong Province(2019-2021).
文摘Graphene oxide(GO),a derivative of graphene,is a novel carbon material that has attracted a lot of attention in the field of membrane materials as its ability to achieve layer-by-layer stacking and the formation of nanochannels between the lamellae makes it excellent for selective separation of substances.In this paper,the separation mechanism of the GO membrane is summarized.According to the different separation substances,the separation mechanism of graphene oxide membrane is reviewed from two aspects of metal ions and organic pollutants.Next,the preparation methods of graphene oxide membranes is introduced,such as spin-coating,vacuum filtration,dip-coating,spraying,and layer-by-layer self-assembly,followed by a review on the structural regulation of GO.Finally,this paper concludes with an overview of the potential development prospects and challenges of GO membranes.
