China has been experiencing widespread air pollution due to rapid industrialization and urbanization in recent decades.The two major concerns of ambient air quality in China are particulate matter(PM)and tropospheric ...China has been experiencing widespread air pollution due to rapid industrialization and urbanization in recent decades.The two major concerns of ambient air quality in China are particulate matter(PM)and tropospheric ozone(O3).With the implementation of air pollution prevention and control actions in the last five years,the PM pollution in China has been substantially reduced.In contrast,under the conditions of the urban air pollution complex,the elevated O3 levels in city clusters of eastern China,especially in warm seasons,have drawn increasing attention.Emissions of air pollutants and their precursors not only contribute to regional air quality,but also alter climate.Climate change in turn can change chemical processes,long-range transport,and local meteorology that influence air pollution.Compared to PM,less is known about O3 pollution and its climate effects over China.Here,we present a review of the main findings from the literature over the period 2011-18 with regard to the characteristics of O3 concentrations in China and the mechanisms that drive its interannual to decadal variations,aiming to identify robust conclusions that may guide decision-making for emissions control and to highlight critical knowledge gaps.We also review regional and global modeling studies that have investigated the impacts of tropospheric O3 on climate,as well as the projections of future tropospheric O3 owing to climate and/or emission changes.展开更多
In the present work,an incompressible smoothed particle hydrodynamic(SPH)method is introduced to simulate water-soil-structure interactions.In the current calculation,the water is modelled as a Newtonian fluid.The soi...In the present work,an incompressible smoothed particle hydrodynamic(SPH)method is introduced to simulate water-soil-structure interactions.In the current calculation,the water is modelled as a Newtonian fluid.The soil is modelled in two different cases.In the first case,the granular material is considered as a fluid where a Bingham type constitutive model is proposed based on Mohr-Coulomb yield-stress criterion,and the viscosity is derived from the cohesion and friction angle.In addition,the fictitious suspension layers between water and soil depending on the concentration of soil are introduced.In the second case,Hooke’s law introduces elastic soil.In ISPH,the pressure is evaluated by solving the pressure Poisson equation using a semi-implicit algorithm based on the projection method and an eddy viscosity for water is modelled by a large eddy simulation with the Smagorinsky model.In the proposed ISPH method,the pressure is stabilized to simulate the multiphase flow between soil and water.Numerical experiments for water-soil suspension flow of Louvain erosional dam break with flat soil foundation,is simulated and validated using 3D-ISPH method.Coupling between water-soil interactions with different solid structures are simulated.The results revealed that,the suspension layers with the Bingham model of soil gives more accurate results in the experiment as compared to the case of the Bingham model without suspension layers.In addition,the elastic soil model by the Hooke’s law can simulate soil hump accurately as compared to the Bingham model.From the simulations,avoiding erosion behind the structure for preventing the structure break during flood are investigated by using an extended structure or a wedge structure.展开更多
Gas adsorption has an important influence on gas flow in a coal body.Research on the characteristics of coal and gas adsorption is the theoretical basis for studying gas flow in coal.In this paper,the interaction betw...Gas adsorption has an important influence on gas flow in a coal body.Research on the characteristics of coal and gas adsorption is the theoretical basis for studying gas flow in coal.In this paper,the interaction between methane,carbon dioxide and surface molecules of anthracite was simulated using the quantum chemistry method.Adsorption energy and adsorption configurations of different quantities of gas molecules absorbed on the coal surface were calculated.The results show that adsorption between coal and the two kinds of gas molecules is a physical adsorption process and there is an optimal configuration.Gas molecules are more easily adsorbed in the hydroxyl-containing side chain,while it is difficult for them to be adsorbed at the position of the benzene ring.Besides,carbon dioxide molecules are more readily adsorbed on the coal surface than methane molecules.The findings have an important significance in revealing the nature of gas adsorption in coal.展开更多
Background Augmented reality classrooms have become an interesting research topic in the field of education,but there are some limitations.Firstly,most researchers use cards to operate experiments,and a large number o...Background Augmented reality classrooms have become an interesting research topic in the field of education,but there are some limitations.Firstly,most researchers use cards to operate experiments,and a large number of cards cause difficulty and inconvenience for users.Secondly,most users conduct experiments only in the visual modal,and such single-modal interaction greatly reduces the users'real sense of interaction.In order to solve these problems,we propose the Multimodal Interaction Algorithm based on Augmented Reality(ARGEV),which is based on visual and tactile feedback in Augmented Reality.In addition,we design a Virtual and Real Fusion Interactive Tool Suite(VRFITS)with gesture recognition and intelligent equipment.Methods The ARGVE method fuses gesture,intelligent equipment,and virtual models.We use a gesture recognition model trained by a convolutional neural network to recognize the gestures in AR,and to trigger a vibration feedback after a recognizing a five finger grasp gesture.We establish a coordinate mapping relationship between real hands and the virtual model to achieve the fusion of gestures and the virtual model.Results The average accuracy rate of gesture recognition was 99.04%.We verify and apply VRFITS in the Augmented Reality Chemistry Lab(ARCL),and the overall operation load of ARCL is thus reduced by 29.42%,in comparison to traditional simulation virtual experiments.Conclusions We achieve real-time fusion of the gesture,virtual model,and intelligent equipment in ARCL.Compared with the NOBOOK virtual simulation experiment,ARCL improves the users'real sense of operation and interaction efficiency.展开更多
Typical cationic and anionic surfactants were chosen and their interactions were calculated by quantum chemical method. Interaction energies are -0.2378 kJ·mol^-1, -3.3394 kJ·mol^-1 and 0.1204 kJ·mol^-1...Typical cationic and anionic surfactants were chosen and their interactions were calculated by quantum chemical method. Interaction energies are -0.2378 kJ·mol^-1, -3.3394 kJ·mol^-1 and 0.1204 kJ·mol^-1 for the molecular pairs with fluocarbon and hydrocarbon chain: C4H10/C5H12, C4F10/C5H12, and C4F10 /C5F12, respectively.When hydrophilic group with cationic and anionicions is introduced, interaction energies are -287.40kJ·mol^-1,-311.18 kJ·mo1^-1 and -345.83 kJ·mo1^-1. The results show that there is strong static interaction between cationic and anionic surfactants. It has been predicted that mixed monolayer may be formed and surface activity is enhanced favorably, especially for mixtures of cationic and anionic surfactants with fluocarbon and hydrocarbon chains. The anionic surfactants, sodium octadecylbenzenesulfonate perfluopolyetherbenzenesulonate(ANF-I) was synthesized, mixture effects of ANF-I with sodium octadecylbenzenesulfonate or dodecyldimethyl benzylammonium bromide were studied. The results indicate that the efficiency of mixing increased and the theoretical prediction was testified. These results can provide useful information for the design of new surfactants.展开更多
Water electrolysis poses a significant challenge for balancing catalytic activity and stability of oxygen evolution reaction(OER)electrocatalysts.In this study,we address this challenge by constructing asymmetric redo...Water electrolysis poses a significant challenge for balancing catalytic activity and stability of oxygen evolution reaction(OER)electrocatalysts.In this study,we address this challenge by constructing asymmetric redox chemistry through elaborate surface OO–Ru–OH and bulk Ru–O–Ni/Fe coordination moieties within single-atom Ru-decorated defective NiFe LDH nanosheets(Ru@d-NiFe LDH)in conjunction with strong metal-support interactions(SMSI).Rigorous spectroscopic characterization and theoretical calculations indicate that single-atom Ru can delocalize the O 2p electrons on the surface and optimize d-electron configurations of metal atoms in bulk through SMSI.The^(18)O isotope labeling experiment based on operando differential electrochemical mass spectrometry(DEMS),chemical probe experiments,and theoretical calculations confirm the encouraged surface lattice oxygen,stabilized bulk lattice oxygen,and enhanced adsorption of oxygen-containing intermediates for bulk metals in Ru@d-NiFe LDH,leading to asymmetric redox chemistry for OER.The Ru@d-NiFe LDH electrocatalyst exhibits exceptional performance with an overpotential of 230 mV to achieve 10 mA cm^(−2)and maintains high robustness under industrial current density.This approach for achieving asymmetric redox chemistry through SMSI presents a new avenue for developing high-performance electrocatalysts and instills confidence in its industrial applicability.展开更多
The cellular microenvironment plays a major role in the biological functions of cells.Thus,biomaterials,especially hydrogels,which can be design to mimic the cellular microenvironment,are being increasingly used for c...The cellular microenvironment plays a major role in the biological functions of cells.Thus,biomaterials,especially hydrogels,which can be design to mimic the cellular microenvironment,are being increasingly used for cell encapsulation,delivery,and 3D culture,with the hope of controlling cell functions.Yet,much remains to be understood about the effects of cell-material interactions,and advanced synthetic strategies need to be developed to independently control the mechanical and biochemical properties of hydrogels.To address this challenge,we designed a new hyaluronic acid(HA)-based hydrogel platform using a click and bioorthogonal strain-promoted azide-alkyne cycloaddition(SPAAC)reaction.This approach facilitates the synthesis of hydrogels that are easy to synthesize and sterilize,have minimal swelling,are stable long term,and are cytocompatible.It provides bioorthogonal HA gels over an uncommonly large range of stiffness(0.5-45 kPa),all forming within 1-15 min.More importantly,our approach offers a versatile one-pot procedure to independently tune the hydrogel composition(e.g.,polymer and adhesive peptides).Using this platform,we investigate the independent effects of polymer type,stiffness,and adhesion on the secretory properties of human adipose-derived stromal cells(hASCs)and demonstrate that HA can enhance the secretion of immunomodulatory factors by hASCs.展开更多
Jets caused by burst tubes erode the surrounding soil, eventually leading to issues such as ground collapse. It is therefore highly important to study the mechanisms of soil erosion caused by jets after pipeline leaka...Jets caused by burst tubes erode the surrounding soil, eventually leading to issues such as ground collapse. It is therefore highly important to study the mechanisms of soil erosion caused by jets after pipeline leakage. To investigate the water-soil interaction mechanisms of pipe leakage, this study used transparent soil and developed a three-dimensional experimental device to observe the fluidization process. Changes in the boundary of the fluidization transition area were investigated, and a formula for calculating the soil damage area was derived. The results showed three different shapes of the fluidized cavity appearing in the fluidization process. The particles initially moved upward and then gradually transitioned into a state of backflow. The effects of particle size, upper load, and porosity on fluidization were also analyzed. It was found that soil with a large particle size and a lower porosity under a heavy upper load can effectively restrain fluidization. Therefore, large-diameter and dense soil can be used as pipe-covering material.展开更多
Understanding the regulatory mechanism of self-assembly processes is a necessity to modulate nanostructures and their properties. Herein, we have studied the mechanism of self-assembly in the C3 symmetric 1,3,5-benzen...Understanding the regulatory mechanism of self-assembly processes is a necessity to modulate nanostructures and their properties. Herein, we have studied the mechanism of self-assembly in the C3 symmetric 1,3,5-benzentricarboxylic amino acid methyl ester enantiomers(TPE) in a mixed solvent system consisting of methanol and water. The resultant chiral structure was used for chiral recognition. The formation of chiral structures from the synergistic effect of multiple noncovalent interaction forces was confirmed by various techniques. Molecular dynamics simulations were used to characterize the time evolution of TPE structure and properties in solution. The theoretical results were consistent with the experimental results. Furthermore, the chiral structure assembled by the building blocks of TPE molecules was highly stereoselective for diamine compounds.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.91744311 and91544219)the National Key Research and Development Program of China(Grant No.2016YFA0600203)the National Natural Science Foundation of China(Grant No.41405138)
文摘China has been experiencing widespread air pollution due to rapid industrialization and urbanization in recent decades.The two major concerns of ambient air quality in China are particulate matter(PM)and tropospheric ozone(O3).With the implementation of air pollution prevention and control actions in the last five years,the PM pollution in China has been substantially reduced.In contrast,under the conditions of the urban air pollution complex,the elevated O3 levels in city clusters of eastern China,especially in warm seasons,have drawn increasing attention.Emissions of air pollutants and their precursors not only contribute to regional air quality,but also alter climate.Climate change in turn can change chemical processes,long-range transport,and local meteorology that influence air pollution.Compared to PM,less is known about O3 pollution and its climate effects over China.Here,we present a review of the main findings from the literature over the period 2011-18 with regard to the characteristics of O3 concentrations in China and the mechanisms that drive its interannual to decadal variations,aiming to identify robust conclusions that may guide decision-making for emissions control and to highlight critical knowledge gaps.We also review regional and global modeling studies that have investigated the impacts of tropospheric O3 on climate,as well as the projections of future tropospheric O3 owing to climate and/or emission changes.
基金This work was supported by Deanship of Scientific Research at King Khalid University,Abha,Saudi Arabia,through the Research Group Project under grant number R.G.P2/70/41.
文摘In the present work,an incompressible smoothed particle hydrodynamic(SPH)method is introduced to simulate water-soil-structure interactions.In the current calculation,the water is modelled as a Newtonian fluid.The soil is modelled in two different cases.In the first case,the granular material is considered as a fluid where a Bingham type constitutive model is proposed based on Mohr-Coulomb yield-stress criterion,and the viscosity is derived from the cohesion and friction angle.In addition,the fictitious suspension layers between water and soil depending on the concentration of soil are introduced.In the second case,Hooke’s law introduces elastic soil.In ISPH,the pressure is evaluated by solving the pressure Poisson equation using a semi-implicit algorithm based on the projection method and an eddy viscosity for water is modelled by a large eddy simulation with the Smagorinsky model.In the proposed ISPH method,the pressure is stabilized to simulate the multiphase flow between soil and water.Numerical experiments for water-soil suspension flow of Louvain erosional dam break with flat soil foundation,is simulated and validated using 3D-ISPH method.Coupling between water-soil interactions with different solid structures are simulated.The results revealed that,the suspension layers with the Bingham model of soil gives more accurate results in the experiment as compared to the case of the Bingham model without suspension layers.In addition,the elastic soil model by the Hooke’s law can simulate soil hump accurately as compared to the Bingham model.From the simulations,avoiding erosion behind the structure for preventing the structure break during flood are investigated by using an extended structure or a wedge structure.
基金foundation by the National Key Basic Research and Development Project Program of China(No.2011CB201202-2)the Research Fund for the Doctoral Program of Higher Education(No.20120023120005)+1 种基金the Foundation of State Key Laboratory of Coal Resources and Safety Mining(No.SKLCRSM11KFB04)the Fundamental Research Funds for the Central Universities(No.2009kz03)
文摘Gas adsorption has an important influence on gas flow in a coal body.Research on the characteristics of coal and gas adsorption is the theoretical basis for studying gas flow in coal.In this paper,the interaction between methane,carbon dioxide and surface molecules of anthracite was simulated using the quantum chemistry method.Adsorption energy and adsorption configurations of different quantities of gas molecules absorbed on the coal surface were calculated.The results show that adsorption between coal and the two kinds of gas molecules is a physical adsorption process and there is an optimal configuration.Gas molecules are more easily adsorbed in the hydroxyl-containing side chain,while it is difficult for them to be adsorbed at the position of the benzene ring.Besides,carbon dioxide molecules are more readily adsorbed on the coal surface than methane molecules.The findings have an important significance in revealing the nature of gas adsorption in coal.
基金the National Key R&D Program of China(2018YFB1004901)the Independent Innovation Team Project of Jinan City(2019GXRC013).
文摘Background Augmented reality classrooms have become an interesting research topic in the field of education,but there are some limitations.Firstly,most researchers use cards to operate experiments,and a large number of cards cause difficulty and inconvenience for users.Secondly,most users conduct experiments only in the visual modal,and such single-modal interaction greatly reduces the users'real sense of interaction.In order to solve these problems,we propose the Multimodal Interaction Algorithm based on Augmented Reality(ARGEV),which is based on visual and tactile feedback in Augmented Reality.In addition,we design a Virtual and Real Fusion Interactive Tool Suite(VRFITS)with gesture recognition and intelligent equipment.Methods The ARGVE method fuses gesture,intelligent equipment,and virtual models.We use a gesture recognition model trained by a convolutional neural network to recognize the gestures in AR,and to trigger a vibration feedback after a recognizing a five finger grasp gesture.We establish a coordinate mapping relationship between real hands and the virtual model to achieve the fusion of gestures and the virtual model.Results The average accuracy rate of gesture recognition was 99.04%.We verify and apply VRFITS in the Augmented Reality Chemistry Lab(ARCL),and the overall operation load of ARCL is thus reduced by 29.42%,in comparison to traditional simulation virtual experiments.Conclusions We achieve real-time fusion of the gesture,virtual model,and intelligent equipment in ARCL.Compared with the NOBOOK virtual simulation experiment,ARCL improves the users'real sense of operation and interaction efficiency.
文摘Typical cationic and anionic surfactants were chosen and their interactions were calculated by quantum chemical method. Interaction energies are -0.2378 kJ·mol^-1, -3.3394 kJ·mol^-1 and 0.1204 kJ·mol^-1 for the molecular pairs with fluocarbon and hydrocarbon chain: C4H10/C5H12, C4F10/C5H12, and C4F10 /C5F12, respectively.When hydrophilic group with cationic and anionicions is introduced, interaction energies are -287.40kJ·mol^-1,-311.18 kJ·mo1^-1 and -345.83 kJ·mo1^-1. The results show that there is strong static interaction between cationic and anionic surfactants. It has been predicted that mixed monolayer may be formed and surface activity is enhanced favorably, especially for mixtures of cationic and anionic surfactants with fluocarbon and hydrocarbon chains. The anionic surfactants, sodium octadecylbenzenesulfonate perfluopolyetherbenzenesulonate(ANF-I) was synthesized, mixture effects of ANF-I with sodium octadecylbenzenesulfonate or dodecyldimethyl benzylammonium bromide were studied. The results indicate that the efficiency of mixing increased and the theoretical prediction was testified. These results can provide useful information for the design of new surfactants.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2021B1515120072)the Natural Science Foundation of China(22279096 and T2241003)the Fundamental Research Funds for the Central Universities(WUT:2023IVA094).
文摘Water electrolysis poses a significant challenge for balancing catalytic activity and stability of oxygen evolution reaction(OER)electrocatalysts.In this study,we address this challenge by constructing asymmetric redox chemistry through elaborate surface OO–Ru–OH and bulk Ru–O–Ni/Fe coordination moieties within single-atom Ru-decorated defective NiFe LDH nanosheets(Ru@d-NiFe LDH)in conjunction with strong metal-support interactions(SMSI).Rigorous spectroscopic characterization and theoretical calculations indicate that single-atom Ru can delocalize the O 2p electrons on the surface and optimize d-electron configurations of metal atoms in bulk through SMSI.The^(18)O isotope labeling experiment based on operando differential electrochemical mass spectrometry(DEMS),chemical probe experiments,and theoretical calculations confirm the encouraged surface lattice oxygen,stabilized bulk lattice oxygen,and enhanced adsorption of oxygen-containing intermediates for bulk metals in Ru@d-NiFe LDH,leading to asymmetric redox chemistry for OER.The Ru@d-NiFe LDH electrocatalyst exhibits exceptional performance with an overpotential of 230 mV to achieve 10 mA cm^(−2)and maintains high robustness under industrial current density.This approach for achieving asymmetric redox chemistry through SMSI presents a new avenue for developing high-performance electrocatalysts and instills confidence in its industrial applicability.
基金the Fondation de l’Avenir pour la Recherche Médicale Appliquée(AP-RM-18-005,CLV)the Fondation pour la Recherche M´edicale(ARF201809007012,VD)+1 种基金the Nantes Excellence Trajectory program(NExT Junior Talent 2018,VD,NexT IIP Shelby 2018,CLV)the Marie-Sklodowska Curie Actions(BABHY-CART project,GAP-846477,VD)for their financial support.
文摘The cellular microenvironment plays a major role in the biological functions of cells.Thus,biomaterials,especially hydrogels,which can be design to mimic the cellular microenvironment,are being increasingly used for cell encapsulation,delivery,and 3D culture,with the hope of controlling cell functions.Yet,much remains to be understood about the effects of cell-material interactions,and advanced synthetic strategies need to be developed to independently control the mechanical and biochemical properties of hydrogels.To address this challenge,we designed a new hyaluronic acid(HA)-based hydrogel platform using a click and bioorthogonal strain-promoted azide-alkyne cycloaddition(SPAAC)reaction.This approach facilitates the synthesis of hydrogels that are easy to synthesize and sterilize,have minimal swelling,are stable long term,and are cytocompatible.It provides bioorthogonal HA gels over an uncommonly large range of stiffness(0.5-45 kPa),all forming within 1-15 min.More importantly,our approach offers a versatile one-pot procedure to independently tune the hydrogel composition(e.g.,polymer and adhesive peptides).Using this platform,we investigate the independent effects of polymer type,stiffness,and adhesion on the secretory properties of human adipose-derived stromal cells(hASCs)and demonstrate that HA can enhance the secretion of immunomodulatory factors by hASCs.
基金supported by the National Natural Science Foundation of China(Grant No.52070165)the Major Science and Technology Project of Zhejiang Province,China(Grant No.2015C03015).
文摘Jets caused by burst tubes erode the surrounding soil, eventually leading to issues such as ground collapse. It is therefore highly important to study the mechanisms of soil erosion caused by jets after pipeline leakage. To investigate the water-soil interaction mechanisms of pipe leakage, this study used transparent soil and developed a three-dimensional experimental device to observe the fluidization process. Changes in the boundary of the fluidization transition area were investigated, and a formula for calculating the soil damage area was derived. The results showed three different shapes of the fluidized cavity appearing in the fluidization process. The particles initially moved upward and then gradually transitioned into a state of backflow. The effects of particle size, upper load, and porosity on fluidization were also analyzed. It was found that soil with a large particle size and a lower porosity under a heavy upper load can effectively restrain fluidization. Therefore, large-diameter and dense soil can be used as pipe-covering material.
基金supported by the National Natural Science Foundation of China(No.21962003)the Natural Science Foundation of Jiangsu Province(No.BK20190056)the“Fundamental Research Funds for the Central Universities”(No.021514380014)。
文摘Understanding the regulatory mechanism of self-assembly processes is a necessity to modulate nanostructures and their properties. Herein, we have studied the mechanism of self-assembly in the C3 symmetric 1,3,5-benzentricarboxylic amino acid methyl ester enantiomers(TPE) in a mixed solvent system consisting of methanol and water. The resultant chiral structure was used for chiral recognition. The formation of chiral structures from the synergistic effect of multiple noncovalent interaction forces was confirmed by various techniques. Molecular dynamics simulations were used to characterize the time evolution of TPE structure and properties in solution. The theoretical results were consistent with the experimental results. Furthermore, the chiral structure assembled by the building blocks of TPE molecules was highly stereoselective for diamine compounds.
