The oil / water two-phase flow inside T-junctions was numerically simulated with a 3-D two-fluid model, and the turbulence was described using the mixture k- ε model. Some experiments of oil / water flow inside a sin...The oil / water two-phase flow inside T-junctions was numerically simulated with a 3-D two-fluid model, and the turbulence was described using the mixture k- ε model. Some experiments of oil / water flow inside a single T-junction were conducted in the laboratory. The results show that the separating performance of T-junction largely depends on the inlet volumetric fraction and flow patterns. A reasonable agreement is reached between the numerical simulation and the experiments for both the oil fraction distribution and the separation efficiency.展开更多
Single-molecule junctions,integrating individual molecules as active components between electrodes,serve as fundamental building blocks for advanced electronic and sensing technologies.The application of ionic liquids...Single-molecule junctions,integrating individual molecules as active components between electrodes,serve as fundamental building blocks for advanced electronic and sensing technologies.The application of ionic liquids in single-molecule junctions represents a cutting-edge and rapidly evolving field of research at the intersection of nanoscience,materials chemistry,and electronics.This review explores recent advances where ionic liquids function as electrolytes,dielectric layers,and structural elements within single-molecule junctions,reshaping charge transport,redox reactions,and molecular behaviors in these nanoscale systems.We comprehensively dissect fundamental concepts,techniques,and modulation mechanisms,elucidating the roles of ionic liquids as gates,electrochemical controllers,and interface components in singlemolecule junctions.Encompassing applications from functional device construction to unraveling intricate chemical reactions,this review maps the diverse applications of ionic liquids in single-molecule junctions.Moreover,we propose critical future research topics in this field,including catalysis involving ionic liquids at the single-molecule level,functionalizing single-molecule devices using ionic liquids,and probing the structure and interactions of ionic liquids.These endeavors aim to drive technological breakthroughs in nanotechnology,energy,and quantum research.展开更多
The second dissociation constant, pK2, and related thermodynamic quantities for TAPSO have been previously determined and reported from the temperatures (278.15 to 328.15) K. In the current study there are five buffer...The second dissociation constant, pK2, and related thermodynamic quantities for TAPSO have been previously determined and reported from the temperatures (278.15 to 328.15) K. In the current study there are five buffer solutions without NaCl and five buffer solutions with NaCl present which yield an ionic strength (I = 0.16 mol·kg-1) similar to that of blood plasma. These buffer solutions have been evaluated in the temperature range of (278.15 to 328.15) K using the extended Debye-Hückel equation, due to the limitations of the Bates-Guggenheim convention such that it is only valid when I -1. The liquid junction potential (Ej) values between the TAPSO solution and the saturated KCl calomel electrode solution have been estimated at (298.15 and 310.15) K using a flowing junction cell measurement. The previously mentioned Ej values have been used in determining the operational pH values at (298.15 and 310.15) K. These TAPSO buffer solutions are recommended as reference solutions for pH measurements in saline media with an ionic strength of I = 0.16 mol·kg-1.展开更多
The second acidic dissociation constants of protonated piperazine-N,N′-bis-2-hydroxypropane-sulfonic acid (POPSO sesquisodium salt) have been determined at 12 different temperatures from (278.15 to 328.15) K includin...The second acidic dissociation constants of protonated piperazine-N,N′-bis-2-hydroxypropane-sulfonic acid (POPSO sesquisodium salt) have been determined at 12 different temperatures from (278.15 to 328.15) K including 310.15 K. Electromotive-force measurement technique was used employing hydrogen-silver chloride cells without liquid junction. The results of pK2 are given by the equation: pK2 = -1041.77/T + 51.0459 - 6.97646lnT. The uncertainty of the fit is ±0.0008. At 289.15 K, pK2 = 7.8029;whereas, at 310.15 K (body temperature), pK2 = 7.6862. Thus, the buffer solutions of POPSO and its sodium salt are useful for pH control in the physiological pH region of (7.0 to 8.5). The changes of Gibbs free energy (G°), enthalpy (H°), entropy (S°) and heat capacity Cp° were computed from the temperature derivative of the pK2 for the dissociation of the zwitterionic acid POPSO±-3 = POPSO-4 + H+ in the standard state. At 298.15 K, these results are compared with those of similar components, which are the derivatives of the parent compounds TAURINE, PIPERAZINE and MORPHOLINE.展开更多
This paper reports the results for the pH of three buffer solutions free of chloride ion. The remaining six buffer solutions have saline media of the ionic strength I = 0.16 mol.kg-1, matching closely to that of the p...This paper reports the results for the pH of three buffer solutions free of chloride ion. The remaining six buffer solutions have saline media of the ionic strength I = 0.16 mol.kg-1, matching closely to that of the physiological sample. Conventional paH values for the three buffer solutions without the chloride ion and six buffer solutions with the chloride ion at I = 0.16 mol.kg-1 from 5°C to 55°C have been calculated. The operational pH values for five buffer solutions at 5°C and 55°C have been determined based on the difference in the values of the liquid junction potentials between the blood phosphate standard and the experimental buffer solutions. Five of these buffers are recommended as standards for the physiological pH range 7.5 to 8.5.展开更多
This paper is a report on the development of a convenient approach to fabricating a very efficient hybrid photoelectrocatalyst for water splitting.This photoelectrocatalyst consists of nickel-cobalt layered double hyd...This paper is a report on the development of a convenient approach to fabricating a very efficient hybrid photoelectrocatalyst for water splitting.This photoelectrocatalyst consists of nickel-cobalt layered double hydroxide as the core,cadmium sulfide as the shell,and nitrogen,hence NiCo-LDH@CdS-N.For the electrocatalytic activity to be improved,the H_(2) and O_(2) binding energy needs to be weakened.The interstitial nitrogen doping on NiCo-LDH@CdS can increase electrocatalytic activity to a great extent.NiCoLDH@CdS nanoparticles are obtained by subjecting to nitriding the NiCo-LDH@CdS electrode coated with polyvinylpyrrolidone nanosheets.This electrode has a large specific surface area,allows fast transfer of electrons,and exhibits long-term stability.The experimental results presented in this paper reveal that interstitial nitrogen doping largely reduces H_(2) and O_(2) binding energy and lowers the activation barrier for the formation and splitting of water.展开更多
The present study demonstrates the comparison of erosion rate of critical pipeline parts, namely elbow and T-junction which face the maximum erosion in a pipeline and may cause an early damage and failure of the syste...The present study demonstrates the comparison of erosion rate of critical pipeline parts, namely elbow and T-junction which face the maximum erosion in a pipeline and may cause an early damage and failure of the system. CFD （computational fluid dynamics） with an Eulerian-Lagrangian approach coupled with an approved erosion model is applied to visualize the 3-D flow behavior of slurry flow in both parts and to predict the erosion rate and the location of erosion at the internal surfaces. The analysis of slurry erosion is performed in five steps; geometry and grid generation, grid study/refinement, fluid flow solution, solid particles tracking and finally, the erosion calculation. In previous publications in literature considering transportation of gas-solid flows in pipe parts, the application ofT-junctions instead of elbows for specified conditions in order to reduce the erosion is recommended. In this article, it is approved that for liquid-solid flows, the Stokes number is reasonably smaller than the values for gas-solid flows. This causes the solid particles tightly couple to the fluid phase and to travel more closely with the fluid streamlines. The effects of important influencing parameters such as feed flow velocity, solid concentration, particle size and shape are investigated in detail in current work. It was found that for liquid-solid flows, the erosion of T-junction for all of the mentioned influencing parameters, due to its geometrical specifications and Stokes number variation in comparison with gas-solid flows, is reasonably higher than erosion of elbow. Due to these findings, in contrary to the gas-solid mixture flows, application of T-junction instead of elbow for liquid-solid flow transportation is not recommended.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.10572143)
文摘The oil / water two-phase flow inside T-junctions was numerically simulated with a 3-D two-fluid model, and the turbulence was described using the mixture k- ε model. Some experiments of oil / water flow inside a single T-junction were conducted in the laboratory. The results show that the separating performance of T-junction largely depends on the inlet volumetric fraction and flow patterns. A reasonable agreement is reached between the numerical simulation and the experiments for both the oil fraction distribution and the separation efficiency.
基金primary financial supports from the National Key R&D Program of China(2021YFA1200102,2021YFA1200101,and 2022YFE0128700)the National Natural Science Foundation of China(22173050,22150013,21727806,and 21933001)+4 种基金the New Cornerstone Science Foundation through the XPLORER PRIZEthe Natural Science Foundation of Beijing(2222009)Beijing National Laboratory for Molecular Sciences(BNLMS202105)the Fundamental Research Funds for the Central Universities(63223056)“Frontiers Science Center for New Organic Matter”at Nankai University(63181206).
文摘Single-molecule junctions,integrating individual molecules as active components between electrodes,serve as fundamental building blocks for advanced electronic and sensing technologies.The application of ionic liquids in single-molecule junctions represents a cutting-edge and rapidly evolving field of research at the intersection of nanoscience,materials chemistry,and electronics.This review explores recent advances where ionic liquids function as electrolytes,dielectric layers,and structural elements within single-molecule junctions,reshaping charge transport,redox reactions,and molecular behaviors in these nanoscale systems.We comprehensively dissect fundamental concepts,techniques,and modulation mechanisms,elucidating the roles of ionic liquids as gates,electrochemical controllers,and interface components in singlemolecule junctions.Encompassing applications from functional device construction to unraveling intricate chemical reactions,this review maps the diverse applications of ionic liquids in single-molecule junctions.Moreover,we propose critical future research topics in this field,including catalysis involving ionic liquids at the single-molecule level,functionalizing single-molecule devices using ionic liquids,and probing the structure and interactions of ionic liquids.These endeavors aim to drive technological breakthroughs in nanotechnology,energy,and quantum research.
文摘The second dissociation constant, pK2, and related thermodynamic quantities for TAPSO have been previously determined and reported from the temperatures (278.15 to 328.15) K. In the current study there are five buffer solutions without NaCl and five buffer solutions with NaCl present which yield an ionic strength (I = 0.16 mol·kg-1) similar to that of blood plasma. These buffer solutions have been evaluated in the temperature range of (278.15 to 328.15) K using the extended Debye-Hückel equation, due to the limitations of the Bates-Guggenheim convention such that it is only valid when I -1. The liquid junction potential (Ej) values between the TAPSO solution and the saturated KCl calomel electrode solution have been estimated at (298.15 and 310.15) K using a flowing junction cell measurement. The previously mentioned Ej values have been used in determining the operational pH values at (298.15 and 310.15) K. These TAPSO buffer solutions are recommended as reference solutions for pH measurements in saline media with an ionic strength of I = 0.16 mol·kg-1.
文摘The second acidic dissociation constants of protonated piperazine-N,N′-bis-2-hydroxypropane-sulfonic acid (POPSO sesquisodium salt) have been determined at 12 different temperatures from (278.15 to 328.15) K including 310.15 K. Electromotive-force measurement technique was used employing hydrogen-silver chloride cells without liquid junction. The results of pK2 are given by the equation: pK2 = -1041.77/T + 51.0459 - 6.97646lnT. The uncertainty of the fit is ±0.0008. At 289.15 K, pK2 = 7.8029;whereas, at 310.15 K (body temperature), pK2 = 7.6862. Thus, the buffer solutions of POPSO and its sodium salt are useful for pH control in the physiological pH region of (7.0 to 8.5). The changes of Gibbs free energy (G°), enthalpy (H°), entropy (S°) and heat capacity Cp° were computed from the temperature derivative of the pK2 for the dissociation of the zwitterionic acid POPSO±-3 = POPSO-4 + H+ in the standard state. At 298.15 K, these results are compared with those of similar components, which are the derivatives of the parent compounds TAURINE, PIPERAZINE and MORPHOLINE.
文摘This paper reports the results for the pH of three buffer solutions free of chloride ion. The remaining six buffer solutions have saline media of the ionic strength I = 0.16 mol.kg-1, matching closely to that of the physiological sample. Conventional paH values for the three buffer solutions without the chloride ion and six buffer solutions with the chloride ion at I = 0.16 mol.kg-1 from 5°C to 55°C have been calculated. The operational pH values for five buffer solutions at 5°C and 55°C have been determined based on the difference in the values of the liquid junction potentials between the blood phosphate standard and the experimental buffer solutions. Five of these buffers are recommended as standards for the physiological pH range 7.5 to 8.5.
文摘This paper is a report on the development of a convenient approach to fabricating a very efficient hybrid photoelectrocatalyst for water splitting.This photoelectrocatalyst consists of nickel-cobalt layered double hydroxide as the core,cadmium sulfide as the shell,and nitrogen,hence NiCo-LDH@CdS-N.For the electrocatalytic activity to be improved,the H_(2) and O_(2) binding energy needs to be weakened.The interstitial nitrogen doping on NiCo-LDH@CdS can increase electrocatalytic activity to a great extent.NiCoLDH@CdS nanoparticles are obtained by subjecting to nitriding the NiCo-LDH@CdS electrode coated with polyvinylpyrrolidone nanosheets.This electrode has a large specific surface area,allows fast transfer of electrons,and exhibits long-term stability.The experimental results presented in this paper reveal that interstitial nitrogen doping largely reduces H_(2) and O_(2) binding energy and lowers the activation barrier for the formation and splitting of water.
文摘The present study demonstrates the comparison of erosion rate of critical pipeline parts, namely elbow and T-junction which face the maximum erosion in a pipeline and may cause an early damage and failure of the system. CFD （computational fluid dynamics） with an Eulerian-Lagrangian approach coupled with an approved erosion model is applied to visualize the 3-D flow behavior of slurry flow in both parts and to predict the erosion rate and the location of erosion at the internal surfaces. The analysis of slurry erosion is performed in five steps; geometry and grid generation, grid study/refinement, fluid flow solution, solid particles tracking and finally, the erosion calculation. In previous publications in literature considering transportation of gas-solid flows in pipe parts, the application ofT-junctions instead of elbows for specified conditions in order to reduce the erosion is recommended. In this article, it is approved that for liquid-solid flows, the Stokes number is reasonably smaller than the values for gas-solid flows. This causes the solid particles tightly couple to the fluid phase and to travel more closely with the fluid streamlines. The effects of important influencing parameters such as feed flow velocity, solid concentration, particle size and shape are investigated in detail in current work. It was found that for liquid-solid flows, the erosion of T-junction for all of the mentioned influencing parameters, due to its geometrical specifications and Stokes number variation in comparison with gas-solid flows, is reasonably higher than erosion of elbow. Due to these findings, in contrary to the gas-solid mixture flows, application of T-junction instead of elbow for liquid-solid flow transportation is not recommended.
