Aqueous rechargeable Ni-Fe batteries exhibit unique advantages in large-scale energy storage thanks to their affordability,safety,and reliability.However,their limited energy density and Coulombic efficiency stem from...Aqueous rechargeable Ni-Fe batteries exhibit unique advantages in large-scale energy storage thanks to their affordability,safety,and reliability.However,their limited energy density and Coulombic efficiency stem from unfavorable OH^(−)adsorption capability and low electrochemical activity of Fe sites,result in electrode kinetic delays for Fe anodes.Here,we report Mn and S co-modified FeOOH(MSFF)nanosheets as an advanced anode in Ni-Fe batteries,synthesized from a facile one-step surface-redox-etching method at room temperature.Based on the strong electronic coupling effect between Mn and S atoms,such MSFF anode presents fast electron transport capability,enhanced OH^(−)-adsorption capability,and redox reactivity.Specifically,the MSFF anode can achieve a high areal capacity of 2 mAh cm^(−2)at 10 mA cm^(−2),which retains a staggering 96%of the initial capacity after undergoing 9000 cycles at a higher current density of 30 mA cm^(−2).In addition,the assembled Ni-Fe battery can provide a capacity of 0.85 mAh cm^(−2)at 16 mA cm^(−2),significantly outperforming most recently reported aqueous rechargeable batteries.This work may offer an innovative and feasible approach for modulating the local electronic structure of high-performance Ni-Fe battery electrode materials.展开更多
The numerical simulation of the fluid flow and the flexible rod(s)interaction is more complicated and has lower efficiency due to the high computational cost.In this paper,a semi-resolved model coupling the computatio...The numerical simulation of the fluid flow and the flexible rod(s)interaction is more complicated and has lower efficiency due to the high computational cost.In this paper,a semi-resolved model coupling the computational fluid dynamics and the flexible rod dynamics is proposed using a two-way domain expansion method.The gov-erning equations of the flexible rod dynamics are discretized and solved by the finite element method,and the fluid flow is simulated by the finite volume method.The interaction between fluids and solid rods is modeled by introducing body force terms into the momentum equations.Referred to the traditional semi-resolved numerical model,an anisotropic Gaussian kernel function method is proposed to specify the interactive forces between flu-ids and solid bodies for non-circle rod cross-sections.A benchmark of the flow passing around a single flexible plate with a rectangular cross-section is used to validate the algorithm.Focused on the engineering applications,a test case of a finite patch of cylinders is implemented to validate the accuracy and efficiency of the coupled model.展开更多
Noether theorem is applied to a variable order fractional multiscale mechano-electrophysiological model of neuron membrane dynamics.The variable orders fractional Lagrange equation of a multiscale mechano-electrophysi...Noether theorem is applied to a variable order fractional multiscale mechano-electrophysiological model of neuron membrane dynamics.The variable orders fractional Lagrange equation of a multiscale mechano-electrophysiological model of neuron membrane dynamics is given.The variable orders fractional Noether symmetry criterion and Noether conserved quantities are given.The forms of variable orders fractional Noether conserved quantities corresponding to Noether symmetry generators solutions of the model under different conditions are discussed in detail,and it is found that the expressions of variable orders fractional Noether conserved quantities are closely dependent on the external nonconservative forces and material parameters of the neuron.展开更多
Carbon-mediated persulfate advanced oxidation processes(PS-AOPs)are appealing in contaminant remediation.For the first time,S,B-co-doped carbon-based persulfate activators were synthesized through direct carbonization...Carbon-mediated persulfate advanced oxidation processes(PS-AOPs)are appealing in contaminant remediation.For the first time,S,B-co-doped carbon-based persulfate activators were synthesized through direct carbonization of sodium lignosulfonate and boric acid.By degrading sulfamethoxazole(SMX),CSB-750 obtained 98.7%removal and 81.4%mineralization within 30 min.In comparison with solo S or B doping,S and B co-doped carbon showed the coupling effect for enhanced catalysis.The rate constant(kobs)of 0.1679 min^(-1)was 22.38-and 279.83-fold higher than those of CS-750(0.0075 min^(-1))and CB-750(0.0006 min^(-1)),respectively.The degradation was efficient at strong acidic and weak basic conditions(pH 3-9).Substantial inhibition effect was presented at strong basic condition(pH 10.95)and in presence of CO_(3)^(2-).The CO_(3)^(2-)-caused inhibition was the combined result of the cooperation of pH and quenching O_(2)^(·-).Thiophene sulfur,BC_(3),BC_(2)O,and structural defects were identified as the active sites for PS activation.Radical and nonradical pathways were both involved in the CSB-750/PS/SMX system,where^(1)O_(2)dominated the degradation,SO_(4)^(·-),·OH and direct electron transfer played the subordinate role,and O_(2)^(·-)served as a precursor for the formation of partial^(1)O_(2).The toxicity of degradation system,the effect of real water matrix,and the reusability of carbocatalysts were comprehensively analyzed.Nine possible degradation pathways were proposed.This work focuses on the catalytic performance improvement through the coupling effect of S,B co-doping,and develops an advanced heteroatom doping system to fabricate carbonaceous persulfate activators.展开更多
Elasto-plastic consolidation is one of the classic coupling questions in geomechanics. To solve this problem, an elasto-plastic constitutive model is derived based on the numerical modeling method. The model is applie...Elasto-plastic consolidation is one of the classic coupling questions in geomechanics. To solve this problem, an elasto-plastic constitutive model is derived based on the numerical modeling method. The model is applied to Blot＇s consolidation theory. Incremental governing partial differential equations are established using this method. According to the stress path, the decoupling condition of these equations is discussed. Based on these conditions, an incremental diffusion equation and uncoupling governing equations are presented. The method is then applied to numerical analyses of three examples. The results show that （1） the effect of the stress path should be taken into account in the simulation of the soil consolidation question; （2） this decoupling method can predict the evolvement of pore water pressure; （3） the settlement using cam-clay model is less than that using numerical model because of dilatancy.展开更多
This paper provides an equation to entangle all known fundamental forces by employing their coupling constants, i.e., strong (α<sub>s</sub>), electromagnetic (α), weak (α<sub>w</sub>), and g...This paper provides an equation to entangle all known fundamental forces by employing their coupling constants, i.e., strong (α<sub>s</sub>), electromagnetic (α), weak (α<sub>w</sub>), and gravitational (α<sub>g</sub>) interaction coupling values. The constant coupling formulation is further indicative of many other fundamental forces with significantly weaker coupling values. As an example, the fifth fundamental force, Kashi’s Force, is found to have a coupling constant of 10<sup>-1446</sup>, which is significantly smaller than the smallest known fundamental force, gravitational force, with an approximate coupling constant value of 10<sup>-38</sup>. Additionally, the paper finds the sum of all fundamental forces based on the equation proposed is equal to 0.118065, which is within the range of effective world value of the strong coupling constant α<sub>s</sub>(M<sup>2</sup>z</sub>).展开更多
Na-W-Mn-Zr-S-P/SiO2 catalysts for oxidative coupling of methane （OCM） were prepared by incipient wetness impregnation, sol-gel and mixture slurry methods. The catalyst prepared by mixture slurry method showed the be...Na-W-Mn-Zr-S-P/SiO2 catalysts for oxidative coupling of methane （OCM） were prepared by incipient wetness impregnation, sol-gel and mixture slurry methods. The catalyst prepared by mixture slurry method showed the best catalytic performance among all samples. In addition, the effects of different addition sequences of Na, W, Mn, Zr, S and P on the catalytic performance were studied. The absence of Na before the addition of Mn and Zr in the catalysts preparation depressed the formation of the active phases of Mn2O3 and ZrO2 and decreased the activities of the catalysts significantly.展开更多
An efficient, practical, highly selective and environmentally benign method is reported for the synthesis of aryl thioethers via the coupling of thiols with aryl boronic acids in the presence of NaOH and a catalytic a...An efficient, practical, highly selective and environmentally benign method is reported for the synthesis of aryl thioethers via the coupling of thiols with aryl boronic acids in the presence of NaOH and a catalytic amount of CuSO4 at 130 ℃ using water as a green solvent. The products were obtained in moderate to excellent yields;more importantly, the use of toxic ligands and solvents was avoided. A broad range of aryl boronic acids and scalable processes make this methodology valuable and versatile for the synthesis of a broad range of aryl sulfides.展开更多
Chemo-mechanical coupling behavior of materials is a transformation process between mechanical and chemical energy.In this paper,based on the coupled chemo-mechanical constitutive equations and governing equations dur...Chemo-mechanical coupling behavior of materials is a transformation process between mechanical and chemical energy.In this paper,based on the coupled chemo-mechanical constitutive equations and governing equations during isothermal process,the equivalent integral forms of chemo-mechanical coupling governing equations and corresponding finite element procedure are obtained by using Hamilton’s principle.An isoparametric plane element for chemo-mechanical coupling is associated into ABAQUS finite element package through user element subroutine UEL.The numerical examples exhibit that the ionic concentration variation can cause mechanical deformation and mechanical action can produce redistribution of ionic concentration for hydrogels.It is proved that the present developed chemo-mechanical coupling finite element procedure can be utilized to model the coupling behavior of hydrogels effectively.展开更多
Highly regioregular, head-to-tail coupled poly（3-octylesterthiophene） was synthesized by the Pd-catalysed oxidative C--H/C--H coupling polycondensation. The regioregularity of polymer products was confirmed by the 1...Highly regioregular, head-to-tail coupled poly（3-octylesterthiophene） was synthesized by the Pd-catalysed oxidative C--H/C--H coupling polycondensation. The regioregularity of polymer products was confirmed by the 1H-NMR technique. Furthermore, the effects of various reaction factors including polymerization temperature, solvents and catalysts etc. on the yield, molecular weight and structural regioregularity of the resultant polymers were systematically studied. The optical, electrochemical and crystallization properties of the resultant P3OET with different HT regioregularities in solution and film state were studied by UV-Vis and fluorescent spectroscopy, cyclic voltammetry and X-ray diffraction （XRD）, resepectively.展开更多
We report a theoretic study on modulating the spin polarization of charge current in a mesoscopic fourterminal device of cross structure by using the inverse spin hall effect. The scattering region of device is a two-...We report a theoretic study on modulating the spin polarization of charge current in a mesoscopic fourterminal device of cross structure by using the inverse spin hall effect. The scattering region of device is a two-dimensional electron gas （2DEG） with Rashba spin orbital interaction （RSOI）, one of lead is ferromagnetic metal and other three leads are spin-degenerate normal metals. By using Landauer-Biittiker formalism, we found that when a longitudinal charge current flows through 2DEG scattering region from FM lead by external bias, the transverse current can be either a pure spin current or full-polarized charge current due to the combined effect of spin hall effect and its inverse process, and the polarization of this transverse current can be easily controlled by several device parameters such as the Fermi energy, ferromagnetic magnetization, and the RSOI constant. Our method may pave a new way to control the spin polarization of a charge current.展开更多
An efficient and practical synthetic protocol to synthesize nonsymmetrical aryl thioethers by nucleophilic aromatic substitution(S_NAr)reaction of nitroarenes by thiols with potassium phosphate as the catalyst is desc...An efficient and practical synthetic protocol to synthesize nonsymmetrical aryl thioethers by nucleophilic aromatic substitution(S_NAr)reaction of nitroarenes by thiols with potassium phosphate as the catalyst is described.Various moderate to strong electron-withdrawing functional groups are tolerated by the system to provide thioethers in a good to excellent yields.We also showed that the present method allows access to 3 drug examples in a short reaction time.Finally,mechanistic studies suggest that the reaction may form the classic Meisenheimer complex through a two-step additionelimination mechanism.展开更多
We study a general class of holographic superconductor models via the Stiickelberg mechanism in the non-minimal derivative coupling theory in which the charged scalar field is kinetically coupling to Einstein＇s tenso...We study a general class of holographic superconductor models via the Stiickelberg mechanism in the non-minimal derivative coupling theory in which the charged scalar field is kinetically coupling to Einstein＇s tensor. We explore the effects of the coupling parameter on the critical temperature, the order of phase transitions and the critical expo- nents near the second-order phase transition point. Moreover, we compute the electrical conductivity using the probe approximation and check the ratios wg/Tc for the different coupling parameters.展开更多
We report a theoretic study on the inverse spin-Hall effect （ISHE） in a two-terminal nano-device that consists of a two-dimensional electron gas （2DEG） with Rashba spin-orbit coupling （RSOC） and two ideal leads....We report a theoretic study on the inverse spin-Hall effect （ISHE） in a two-terminal nano-device that consists of a two-dimensional electron gas （2DEG） with Rashba spin-orbit coupling （RSOC） and two ideal leads. Based on a two-site toy model and Keldysh Green＇s function method, we derive an analytic result of ISHE, which shows clearly that a nonzero transverse charge current stems from the combined effect of the RSOC, the spin bias, and its spin polarization direction in spin space. Our further numerical calculations in a larger system other than two-site lattice model demonstrate that the transverse charge current, dependent on the strength of the RSOC, the Fermi energy of the system, as well as the system size, can exhibit oscillating behavior and even reverse its sign due to Rashba spin precession. These properties may be helpful for eficient detection of the spin current （spin bias） by measuring the transverse charge current in a spin-orbital coupling system.展开更多
Thermal and electron transport through organic molecules attached to three-dimensional gold electrodes in two different configurations, namely para and meta with thiol-terminated junctions is studied theoretically in ...Thermal and electron transport through organic molecules attached to three-dimensional gold electrodes in two different configurations, namely para and meta with thiol-terminated junctions is studied theoretically in the linear response regime using Green＇s function formalism. We used thiol-terminated（–SH bond） benzene units and found a positive thermopower because the highest occupied molecular orbital（HOMO） is near the Fermi energy level. We investigated the influence of molecular length and molecular junction geometry on the thermoelectric properties. Our results show that the thermoelectric properties are highly sensitive to the coupling geometry and the molecular length. In addition, we observed that the interference effects and increasing molecular length can increase the thermoelectric efficiency of device in a specific configuration.展开更多
In this paper in an elegant way will be presented the unity formulas for the coupling constants and the dimensionless physical constants. We reached the conclusion of the simple unification of the fundamental interact...In this paper in an elegant way will be presented the unity formulas for the coupling constants and the dimensionless physical constants. We reached the conclusion of the simple unification of the fundamental interactions. We will find the formulas for the Gravitational constant. It will be presented that the gravitational fine-structure constant is a simple analogy between atomic physics and cosmology. We will find the expression that connects the gravitational fine-structure constant with the four coupling constants. Perhaps the gravitational fine-structure constant is the coupling constant for the fifth force. Also will be presented the simple unification of atomic physics and cosmology. We will find the formulas for the cosmological constant and we will propose a possible solution for the cosmological parameters. Perhaps the shape of the universe is Poincare dodecahedral space. This article will be followed by the energy wave theory and the fractal space-time theory.展开更多
This paper presents the analysis of dynamic characteristics of horizontal axis wind turbine blade, where the mode coupling among axial extension, flap vibration （out-of-plane bend- ing）, lead/lag vibration （in-plan...This paper presents the analysis of dynamic characteristics of horizontal axis wind turbine blade, where the mode coupling among axial extension, flap vibration （out-of-plane bend- ing）, lead/lag vibration （in-plane bending） and torsion is emphasized. By using the Bernoulli-Euler beam to describe the slender blade which is mounted on rigid hub and subjected to unsteady aero- dynamic force, the governing equation and characteristic equation of the coupled vibration of the blade are obtained. Due to the combined influences of mode coupling, centrifugal effect, and the non-uniform distribution of mass and stiffness, the explicit solution of characteristic equation is impossible to obtain. An equivalent transformation based on Green＇s functions is taken for the characteristic equation, and then a system of integrodifferential equations is derived. The nu- merical difference methods are adopted to solve the integrodifferential equations to get natural frequencies and mode shapes. The influences of mode coupling, centrifugal effect, and rotational speed on natural frequencies and mode shapes are analyzed. Results show that： （1） the influence of bending-torsion coupling on natural frequency is tiny; （2） rotation has dramatic influence on bending frequency but little influence on torsion frequency; （3） the influence of bending-bending coupling on dynamic characteristics is notable at high rotational speed; （4） the effect of rotational speed on bending mode is tiny.展开更多
Hirota＇s bilinear direct method is applied to constructing soliton solutions to a special coupled modified Korteweg- de Vries （mKdV） system. Some physical properties such as the spatiotemporal evolution, waveform s...Hirota＇s bilinear direct method is applied to constructing soliton solutions to a special coupled modified Korteweg- de Vries （mKdV） system. Some physical properties such as the spatiotemporal evolution, waveform structure, interactive phenomena of solitons are discussed, especially in the two-soliton case. It is found that different interactive behaviours of solitary waves take place under different parameter conditions of overtaking collision in this system. It is verified that the elastic interaction phenomena exist in this （1＋1）-dimensional integrable coupled model.展开更多
With Hirota＇s bilinear direct method, we study the special coupled KdV system to obtain its new soliton solutions. Then we further discuss soliton evolution, corresponding structures, and interesting interactive phen...With Hirota＇s bilinear direct method, we study the special coupled KdV system to obtain its new soliton solutions. Then we further discuss soliton evolution, corresponding structures, and interesting interactive phenomena in detail with plot. As a result, we find that after the interaction, the solitons make elastic collision and there are no exchanges of their physical quantities including energy, velocity and shape except the phase shift.展开更多
This paper studies the coupled Burgers equation and the high-order Boussinesq-Burgers equation. The Hirota bilinear method is applied to show that the two equations are completely integrable. Multiple-kink （soliton）...This paper studies the coupled Burgers equation and the high-order Boussinesq-Burgers equation. The Hirota bilinear method is applied to show that the two equations are completely integrable. Multiple-kink （soliton） solutions and multiple-singular-kink （soliton） solutions are derived for the two equations.展开更多
基金financially supported by National Natural Science Foundation of China(Nos.52407242,52162025)Specific Research Fund of the Innovation Platform for Academicians of Hainan Province(No.YSPTZX202123).
文摘Aqueous rechargeable Ni-Fe batteries exhibit unique advantages in large-scale energy storage thanks to their affordability,safety,and reliability.However,their limited energy density and Coulombic efficiency stem from unfavorable OH^(−)adsorption capability and low electrochemical activity of Fe sites,result in electrode kinetic delays for Fe anodes.Here,we report Mn and S co-modified FeOOH(MSFF)nanosheets as an advanced anode in Ni-Fe batteries,synthesized from a facile one-step surface-redox-etching method at room temperature.Based on the strong electronic coupling effect between Mn and S atoms,such MSFF anode presents fast electron transport capability,enhanced OH^(−)-adsorption capability,and redox reactivity.Specifically,the MSFF anode can achieve a high areal capacity of 2 mAh cm^(−2)at 10 mA cm^(−2),which retains a staggering 96%of the initial capacity after undergoing 9000 cycles at a higher current density of 30 mA cm^(−2).In addition,the assembled Ni-Fe battery can provide a capacity of 0.85 mAh cm^(−2)at 16 mA cm^(−2),significantly outperforming most recently reported aqueous rechargeable batteries.This work may offer an innovative and feasible approach for modulating the local electronic structure of high-performance Ni-Fe battery electrode materials.
基金supported by Shanghai 2021“Science and Technology Innovation Action Plan”:Social Development Science and Technology Research Project(Grant No.21DZ1202703).
文摘The numerical simulation of the fluid flow and the flexible rod(s)interaction is more complicated and has lower efficiency due to the high computational cost.In this paper,a semi-resolved model coupling the computational fluid dynamics and the flexible rod dynamics is proposed using a two-way domain expansion method.The gov-erning equations of the flexible rod dynamics are discretized and solved by the finite element method,and the fluid flow is simulated by the finite volume method.The interaction between fluids and solid rods is modeled by introducing body force terms into the momentum equations.Referred to the traditional semi-resolved numerical model,an anisotropic Gaussian kernel function method is proposed to specify the interactive forces between flu-ids and solid bodies for non-circle rod cross-sections.A benchmark of the flow passing around a single flexible plate with a rectangular cross-section is used to validate the algorithm.Focused on the engineering applications,a test case of a finite patch of cylinders is implemented to validate the accuracy and efficiency of the coupled model.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12272148 and 11772141).
文摘Noether theorem is applied to a variable order fractional multiscale mechano-electrophysiological model of neuron membrane dynamics.The variable orders fractional Lagrange equation of a multiscale mechano-electrophysiological model of neuron membrane dynamics is given.The variable orders fractional Noether symmetry criterion and Noether conserved quantities are given.The forms of variable orders fractional Noether conserved quantities corresponding to Noether symmetry generators solutions of the model under different conditions are discussed in detail,and it is found that the expressions of variable orders fractional Noether conserved quantities are closely dependent on the external nonconservative forces and material parameters of the neuron.
基金financially supported by the GuangDong Basic and Applied Basic Research Foundation(Nos.2019A1515110649,2020A1515110271,2019A1515110244)the National Natural,Science Fund of China(No.51908127)+1 种基金the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2017)the Research Team in Dongguan University of Technology(No.TDYB2019013)。
文摘Carbon-mediated persulfate advanced oxidation processes(PS-AOPs)are appealing in contaminant remediation.For the first time,S,B-co-doped carbon-based persulfate activators were synthesized through direct carbonization of sodium lignosulfonate and boric acid.By degrading sulfamethoxazole(SMX),CSB-750 obtained 98.7%removal and 81.4%mineralization within 30 min.In comparison with solo S or B doping,S and B co-doped carbon showed the coupling effect for enhanced catalysis.The rate constant(kobs)of 0.1679 min^(-1)was 22.38-and 279.83-fold higher than those of CS-750(0.0075 min^(-1))and CB-750(0.0006 min^(-1)),respectively.The degradation was efficient at strong acidic and weak basic conditions(pH 3-9).Substantial inhibition effect was presented at strong basic condition(pH 10.95)and in presence of CO_(3)^(2-).The CO_(3)^(2-)-caused inhibition was the combined result of the cooperation of pH and quenching O_(2)^(·-).Thiophene sulfur,BC_(3),BC_(2)O,and structural defects were identified as the active sites for PS activation.Radical and nonradical pathways were both involved in the CSB-750/PS/SMX system,where^(1)O_(2)dominated the degradation,SO_(4)^(·-),·OH and direct electron transfer played the subordinate role,and O_(2)^(·-)served as a precursor for the formation of partial^(1)O_(2).The toxicity of degradation system,the effect of real water matrix,and the reusability of carbocatalysts were comprehensively analyzed.Nine possible degradation pathways were proposed.This work focuses on the catalytic performance improvement through the coupling effect of S,B co-doping,and develops an advanced heteroatom doping system to fabricate carbonaceous persulfate activators.
文摘Elasto-plastic consolidation is one of the classic coupling questions in geomechanics. To solve this problem, an elasto-plastic constitutive model is derived based on the numerical modeling method. The model is applied to Blot＇s consolidation theory. Incremental governing partial differential equations are established using this method. According to the stress path, the decoupling condition of these equations is discussed. Based on these conditions, an incremental diffusion equation and uncoupling governing equations are presented. The method is then applied to numerical analyses of three examples. The results show that （1） the effect of the stress path should be taken into account in the simulation of the soil consolidation question; （2） this decoupling method can predict the evolvement of pore water pressure; （3） the settlement using cam-clay model is less than that using numerical model because of dilatancy.
文摘This paper provides an equation to entangle all known fundamental forces by employing their coupling constants, i.e., strong (α<sub>s</sub>), electromagnetic (α), weak (α<sub>w</sub>), and gravitational (α<sub>g</sub>) interaction coupling values. The constant coupling formulation is further indicative of many other fundamental forces with significantly weaker coupling values. As an example, the fifth fundamental force, Kashi’s Force, is found to have a coupling constant of 10<sup>-1446</sup>, which is significantly smaller than the smallest known fundamental force, gravitational force, with an approximate coupling constant value of 10<sup>-38</sup>. Additionally, the paper finds the sum of all fundamental forces based on the equation proposed is equal to 0.118065, which is within the range of effective world value of the strong coupling constant α<sub>s</sub>(M<sup>2</sup>z</sub>).
基金supported by the financial support from National Natural Science Foundation of China (20676116)
文摘Na-W-Mn-Zr-S-P/SiO2 catalysts for oxidative coupling of methane （OCM） were prepared by incipient wetness impregnation, sol-gel and mixture slurry methods. The catalyst prepared by mixture slurry method showed the best catalytic performance among all samples. In addition, the effects of different addition sequences of Na, W, Mn, Zr, S and P on the catalytic performance were studied. The absence of Na before the addition of Mn and Zr in the catalysts preparation depressed the formation of the active phases of Mn2O3 and ZrO2 and decreased the activities of the catalysts significantly.
基金Funded by the National Natural Science Foundation of China(No.21571144)
文摘An efficient, practical, highly selective and environmentally benign method is reported for the synthesis of aryl thioethers via the coupling of thiols with aryl boronic acids in the presence of NaOH and a catalytic amount of CuSO4 at 130 ℃ using water as a green solvent. The products were obtained in moderate to excellent yields;more importantly, the use of toxic ligands and solvents was avoided. A broad range of aryl boronic acids and scalable processes make this methodology valuable and versatile for the synthesis of a broad range of aryl sulfides.
基金The financial support from the National Natural Science Foundation of China under grants#11172012,#11472020 is gratefully acknowledged.
文摘Chemo-mechanical coupling behavior of materials is a transformation process between mechanical and chemical energy.In this paper,based on the coupled chemo-mechanical constitutive equations and governing equations during isothermal process,the equivalent integral forms of chemo-mechanical coupling governing equations and corresponding finite element procedure are obtained by using Hamilton’s principle.An isoparametric plane element for chemo-mechanical coupling is associated into ABAQUS finite element package through user element subroutine UEL.The numerical examples exhibit that the ionic concentration variation can cause mechanical deformation and mechanical action can produce redistribution of ionic concentration for hydrogels.It is proved that the present developed chemo-mechanical coupling finite element procedure can be utilized to model the coupling behavior of hydrogels effectively.
基金financially supported by the National Natural Science Foundation of China(Nos.21604063 and 51373122)China Postdoctoral Science Foundation(No.2016M591392)
文摘Highly regioregular, head-to-tail coupled poly（3-octylesterthiophene） was synthesized by the Pd-catalysed oxidative C--H/C--H coupling polycondensation. The regioregularity of polymer products was confirmed by the 1H-NMR technique. Furthermore, the effects of various reaction factors including polymerization temperature, solvents and catalysts etc. on the yield, molecular weight and structural regioregularity of the resultant polymers were systematically studied. The optical, electrochemical and crystallization properties of the resultant P3OET with different HT regioregularities in solution and film state were studied by UV-Vis and fluorescent spectroscopy, cyclic voltammetry and X-ray diffraction （XRD）, resepectively.
基金Supported by National Natural Science Foundation of China under Grant No.10704016Natural Science Foundation of Jiangsu Province under Grant Nos.BK2007100Ministry of Education of China under Grant No.MEC-20070286036
文摘We report a theoretic study on modulating the spin polarization of charge current in a mesoscopic fourterminal device of cross structure by using the inverse spin hall effect. The scattering region of device is a two-dimensional electron gas （2DEG） with Rashba spin orbital interaction （RSOI）, one of lead is ferromagnetic metal and other three leads are spin-degenerate normal metals. By using Landauer-Biittiker formalism, we found that when a longitudinal charge current flows through 2DEG scattering region from FM lead by external bias, the transverse current can be either a pure spin current or full-polarized charge current due to the combined effect of spin hall effect and its inverse process, and the polarization of this transverse current can be easily controlled by several device parameters such as the Fermi energy, ferromagnetic magnetization, and the RSOI constant. Our method may pave a new way to control the spin polarization of a charge current.
基金financial support by the National Natural Science Foundation of China (No.U1532135)
文摘An efficient and practical synthetic protocol to synthesize nonsymmetrical aryl thioethers by nucleophilic aromatic substitution(S_NAr)reaction of nitroarenes by thiols with potassium phosphate as the catalyst is described.Various moderate to strong electron-withdrawing functional groups are tolerated by the system to provide thioethers in a good to excellent yields.We also showed that the present method allows access to 3 drug examples in a short reaction time.Finally,mechanistic studies suggest that the reaction may form the classic Meisenheimer complex through a two-step additionelimination mechanism.
基金supported by the National Natural Science Foundation of China (Grant No. 10875041)the Program for New Century Excellent Talents in University (Grant No. 10-0165)+2 种基金the Program for Changjiang Scholars and Innovative Research Team in University (Grant No. IRT0964)the Construct Program of Key Disciplines in Hunan Provincethe Project of Knowledge Innovation Program of Chinese Academy of Sciences (Grant No. KJCX2.YW.W10)
文摘We study a general class of holographic superconductor models via the Stiickelberg mechanism in the non-minimal derivative coupling theory in which the charged scalar field is kinetically coupling to Einstein＇s tensor. We explore the effects of the coupling parameter on the critical temperature, the order of phase transitions and the critical expo- nents near the second-order phase transition point. Moreover, we compute the electrical conductivity using the probe approximation and check the ratios wg/Tc for the different coupling parameters.
基金Supported by National Natural Science Foundation of China under Grant No.10704016National Natural Science Foundation of Jiangsu Province under Grant No.BK2007100New Teacher Fund of Ministry of Education of China under Grant No.20070286036
文摘We report a theoretic study on the inverse spin-Hall effect （ISHE） in a two-terminal nano-device that consists of a two-dimensional electron gas （2DEG） with Rashba spin-orbit coupling （RSOC） and two ideal leads. Based on a two-site toy model and Keldysh Green＇s function method, we derive an analytic result of ISHE, which shows clearly that a nonzero transverse charge current stems from the combined effect of the RSOC, the spin bias, and its spin polarization direction in spin space. Our further numerical calculations in a larger system other than two-site lattice model demonstrate that the transverse charge current, dependent on the strength of the RSOC, the Fermi energy of the system, as well as the system size, can exhibit oscillating behavior and even reverse its sign due to Rashba spin precession. These properties may be helpful for eficient detection of the spin current （spin bias） by measuring the transverse charge current in a spin-orbital coupling system.
文摘Thermal and electron transport through organic molecules attached to three-dimensional gold electrodes in two different configurations, namely para and meta with thiol-terminated junctions is studied theoretically in the linear response regime using Green＇s function formalism. We used thiol-terminated（–SH bond） benzene units and found a positive thermopower because the highest occupied molecular orbital（HOMO） is near the Fermi energy level. We investigated the influence of molecular length and molecular junction geometry on the thermoelectric properties. Our results show that the thermoelectric properties are highly sensitive to the coupling geometry and the molecular length. In addition, we observed that the interference effects and increasing molecular length can increase the thermoelectric efficiency of device in a specific configuration.
文摘In this paper in an elegant way will be presented the unity formulas for the coupling constants and the dimensionless physical constants. We reached the conclusion of the simple unification of the fundamental interactions. We will find the formulas for the Gravitational constant. It will be presented that the gravitational fine-structure constant is a simple analogy between atomic physics and cosmology. We will find the expression that connects the gravitational fine-structure constant with the four coupling constants. Perhaps the gravitational fine-structure constant is the coupling constant for the fifth force. Also will be presented the simple unification of atomic physics and cosmology. We will find the formulas for the cosmological constant and we will propose a possible solution for the cosmological parameters. Perhaps the shape of the universe is Poincare dodecahedral space. This article will be followed by the energy wave theory and the fractal space-time theory.
基金supported by the National Natural Science Foundation of China(Nos.11372257 and 11601007)Sichuan Provincial Project for Young Research Group of Scientific and Technological Innovations(2013)+1 种基金the Anhui Provincial Natural Science Foundation(No.1708085QA17)Pre-research Project Funds of Anhui University of Science and Technology(No.2016yz007)
文摘This paper presents the analysis of dynamic characteristics of horizontal axis wind turbine blade, where the mode coupling among axial extension, flap vibration （out-of-plane bend- ing）, lead/lag vibration （in-plane bending） and torsion is emphasized. By using the Bernoulli-Euler beam to describe the slender blade which is mounted on rigid hub and subjected to unsteady aero- dynamic force, the governing equation and characteristic equation of the coupled vibration of the blade are obtained. Due to the combined influences of mode coupling, centrifugal effect, and the non-uniform distribution of mass and stiffness, the explicit solution of characteristic equation is impossible to obtain. An equivalent transformation based on Green＇s functions is taken for the characteristic equation, and then a system of integrodifferential equations is derived. The nu- merical difference methods are adopted to solve the integrodifferential equations to get natural frequencies and mode shapes. The influences of mode coupling, centrifugal effect, and rotational speed on natural frequencies and mode shapes are analyzed. Results show that： （1） the influence of bending-torsion coupling on natural frequency is tiny; （2） rotation has dramatic influence on bending frequency but little influence on torsion frequency; （3） the influence of bending-bending coupling on dynamic characteristics is notable at high rotational speed; （4） the effect of rotational speed on bending mode is tiny.
文摘Hirota＇s bilinear direct method is applied to constructing soliton solutions to a special coupled modified Korteweg- de Vries （mKdV） system. Some physical properties such as the spatiotemporal evolution, waveform structure, interactive phenomena of solitons are discussed, especially in the two-soliton case. It is found that different interactive behaviours of solitary waves take place under different parameter conditions of overtaking collision in this system. It is verified that the elastic interaction phenomena exist in this （1＋1）-dimensional integrable coupled model.
文摘With Hirota＇s bilinear direct method, we study the special coupled KdV system to obtain its new soliton solutions. Then we further discuss soliton evolution, corresponding structures, and interesting interactive phenomena in detail with plot. As a result, we find that after the interaction, the solitons make elastic collision and there are no exchanges of their physical quantities including energy, velocity and shape except the phase shift.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10871117 and 10571110)
文摘This paper studies the coupled Burgers equation and the high-order Boussinesq-Burgers equation. The Hirota bilinear method is applied to show that the two equations are completely integrable. Multiple-kink （soliton） solutions and multiple-singular-kink （soliton） solutions are derived for the two equations.
