Heteroatom doping has emerged as a powerful strategy to optimize the catalytic and adsorption abilities of electrocatalysts by regulating the electronic structure,thereby enabling the development of efficient electroc...Heteroatom doping has emerged as a powerful strategy to optimize the catalytic and adsorption abilities of electrocatalysts by regulating the electronic structure,thereby enabling the development of efficient electrocatalysts for lithium-sulfur(Li-S)batteries.However,the correlation between the properties of doped atoms and adsorptio n-catalytic ability,as well as the interconnection between adsorption strength and catalytic activity,remains underexplored.Herein,we employed halogen atoms(F,Cl,and Br)with different electronegativities to dope nickel phosphide(Ni_(2)P),aiming to modulate the adsorption properties toward lithium polysulfides(LiPSs).We systematically explored the relationship between the electronegativity of the doping atoms and the adsorption strength,followed by exploring the connection between adsorption and catalytic capabilities.Combined experimental and theoretical analyses reveal that doping halogen atoms effectively strengthens d-p orbital hybridization between Ni atoms and S atoms,thereby enhancing LiPSs anchoring and conversion.Specifically,the chemical adsorption capability is enhanced as the electronegativity of the doped atoms increases.Moreover,the catalytic activity presents a volcano-like trend with the enhancement of adsorption performance,wherein the activity initially increases and subsequently diminishes.Therefore,Cl-doped Ni_(2)P with moderate chemisorption ability exhibits optimal redox kinetics in bidirectional sulfur conversion.Consequently,the Li-S batteries with Cl-Ni_(2)P-separators deliver a high-rate capacity of 790 mAh g^(-1)at 5 C and achieve a remarkable areal capacity of 7.36 mAh cm^(-2)under practical conditions(sulfur loading:7.10 mg cm^(-2);electrolyte/sulfur(E/S)ratio:5μL mg^(-1)).This work uncovers the significance of achieving a balance between adsorption and catalytic capabilities,offering insights into designing efficient electrocatalysts for lithium-sulfur batteries.展开更多
We take the contribution of all valence electrons into consideration and propose a new valence electrons equilibration method to calculate the equalized electronegativity including molecular electronegativity, group e...We take the contribution of all valence electrons into consideration and propose a new valence electrons equilibration method to calculate the equalized electronegativity including molecular electronegativity, group electronegativity, and atomic charge. The ionization potential of alkanes and mono-substituted alkanes, the chemical shift of 1H NMR, and the gas phase proton affinity of aliphatic amines, alcohols, and ethers were estimated. All the expressions have good correlations. Moreover, the Sanderson method and Bratsch method were modified on the basis of the valence electrons equilibration theory. The modified Sanderson method and modified Bratsch method are more effective than their original methods to estimate these properties.展开更多
The composition−property relationship of 18 quaternary high entropy diborides(HEBs)consisting of boron and IVB,VB and VIB transition metals(TM)was investigated using first-principles calculations.A valence electron co...The composition−property relationship of 18 quaternary high entropy diborides(HEBs)consisting of boron and IVB,VB and VIB transition metals(TM)was investigated using first-principles calculations.A valence electron concentration−relative electronegativity(VEC−REN)composite descriptor was developed to effectively predict the mechanical properties of HEBs.The results demonstrate that with a fixed VEC,the rise of the REN makes HEBs harder but more brittle when the electronegativity of doped TM atoms is lower than that of boron atoms.However,HEBs become softer and more ductile as REN increases if the doped TM atoms have higher electronegativity than boron atoms.The VEC−REN composite descriptor can accurately classify and predict the mechanical properties of HEBs with different components,which provides important theoretical guidance for the rapid design and development of novel high-entropy ceramic materials.展开更多
The density distributions related to gas electronegativity for c-C4Fs gas, including negative ion, electron number and electron energy densities in the discharge process, are derived theoretically in both plane-to-pla...The density distributions related to gas electronegativity for c-C4Fs gas, including negative ion, electron number and electron energy densities in the discharge process, are derived theoretically in both plane-to-plane and point-to-plane electrode geometries. These calculations have been performed through the Boltzmann equation in the condition of a steady-state Townsend （SST） experiment and a fluid model in the condition of both uniform and non-uniform electric fields. The electronegativity coefficients a = n-/ne of c-C4Fs and SF6 are compared to further describe the electron affinity of c-C4Fs. The result shows that c-C4Fs represents an obvious electron-attachment performance in the discharge process. However, c-C4Fs still has much weaker gas electronegativity than SF6, whose electronegativity coefficient is lower than that of SF6 by at least three orders of magnitude.展开更多
Rare earth catalysts possessing characteristics of cation-anion ion pair show advantages of adjusting electronegativity and steric hindrance of metal active sites, which can control the catalytic performance and stere...Rare earth catalysts possessing characteristics of cation-anion ion pair show advantages of adjusting electronegativity and steric hindrance of metal active sites, which can control the catalytic performance and stereoselectivity better than those of traditional metallocene and Ziegler-Natta catalysts in diene polymerization. In this work, a series of neodymium organic sulfonate complexes,Nd(CF_3SO_3)_3·x H_2O·y L(x, y: the coordination number; L refers to an organic electron donating ligand, such as acetylacetone(acac), isooctyl alcohol(IAOH), tributyl phosphate(TBP), etc.), have been synthesized to form the cationic active species in the presence of alkylaluminum such as Al(i-Bu)_3, AlEt_3, and Al(i-Bu)_2H, which display high activities and distinguishing cis-1,4 selectivities(up to99.9%) for the polymerization of butadiene. The microstructures, yield, molecular weight, and molecular weight distribution of the resulting polymer are well controlled by adjusting electronegativity/steric hindrance of the complexes. In addition, the kinetics, active species, and the possible process of polymerization are also discussed in this article.展开更多
Excited-state intramolecular proton transfer(ESIPT)is favored by researchers because of its unique optical properties.However,there are relatively few systematic studies on the effects of changing the electronegativit...Excited-state intramolecular proton transfer(ESIPT)is favored by researchers because of its unique optical properties.However,there are relatively few systematic studies on the effects of changing the electronegativity of atoms on the ESIPT process and photophysical properties.Therefore,we selected a series of benzoxazole isothiocyanate fluorescent dyes(2-HOB,2-HSB,and 2-HSe B)by theoretical methods,and systematically studied the ESIPT process and photophysical properties by changing the electronegativity of chalcogen atoms.The calculated bond angle,bond length,energy gap,and infrared spectrum analysis show that the order of the strength of intramolecular hydrogen bonding of the three molecules is 2-HOB<2-HSB<2-HSe B.Correspondingly,the magnitude of the energy barrier of the potential energy curve is 2-HOB>2-HSB>2-HSe B.In addition,the calculated electronic spectrum shows that as the atomic electronegativity decreases,the emission spectrum has a redshift.Therefore,this work will offer certain theoretical guidance for the synthesis and application of new dyes based on ESIPT properties.展开更多
One of the novel phenomena of Ar/O_(2)inductively coupled plasma,the delta negative ions density profile is discovered by the fluid simulation at very low electronegativity.The anions delta is found to be formed by th...One of the novel phenomena of Ar/O_(2)inductively coupled plasma,the delta negative ions density profile is discovered by the fluid simulation at very low electronegativity.The anions delta is found to be formed by the collaboration of successive plasma transport phases.The plasma transport itself is affected by the delta,exhibiting many new phenomena.A new type of Helmholtz equation is devised to mathematically explain the delta forming mechanism.For revealing the physics behind,a revised spring oscillator dynamic equation has been constructed according to the Helmholtz equation,in a relevant paper[Zhao S X and Li J Z(2021)Chin.Phys.B 30055202].The investigation about the anions delta distribution is a nice prediction of new phenomenon in low temperature electronegative plasmas,waiting for the validation of related experiments.展开更多
Polychlorinated dibenzothiophenes（PCDTs） are classified as persistent organic pollutants in the environment,so the analysis of PCDTs by their gas chromatographic behaviors is of great significance.Quantitative struc...Polychlorinated dibenzothiophenes（PCDTs） are classified as persistent organic pollutants in the environment,so the analysis of PCDTs by their gas chromatographic behaviors is of great significance.Quantitative structure-retention relationship（QSRR） analysis is a useful technique capable of relating chromatographic retention time to the molecular structure.In this paper,a QSRR study of 37 PCDTs was carried out by using molecular electronegativity distance vector（MEDV） descriptors and multiple linear regression（MLR） and partial least-squares regression（PLS） methods.The correlation coefficient R of established MLR,PLS models,leave-one-out（LOO） cross-validation（CV）,Q2ext were 0.9951,0.9942,0.9839（MLR） and 0.9925,0.9915,0.9833（PLS）,respectively.Results showed that the model exhibited excellent estimate capability for internal sample set and good predictive capability for external sample set.By using MEDV descriptors,the QSRR model can provide a simple and rapid way to predict the gas-chromatographic retention indices of polychlorinated dibenzothiophenes in conditions of lacking standard samples or poor experimental conditions.展开更多
This paper presents the evolution of the electronegativity with the applied power during the E to H mode transition in a radio frequency(rf)inductively coupled plasma(ICP)in a mixture of Ar and O2.The densities of the...This paper presents the evolution of the electronegativity with the applied power during the E to H mode transition in a radio frequency(rf)inductively coupled plasma(ICP)in a mixture of Ar and O2.The densities of the negative ion and the electron,as well as their ratio,i.e.,the electronegativity,are measured as a function of the applied power by laser photo-detachment combined with a microwave resonance probe,under different pressures and O2 contents.Meanwhile,the optical emission intensities at Ar 750.4 nm and O 844.6 nm are monitored via a spectrograph.It was found that by increasing the applied power,the electron density and the optical emission intensity show a similar trench,i.e.,they increase abruptly at a threshold power,suggesting that the E to H mode transition occurs.With the increase of the pressure,the negative ion density presents opposite trends in the E-mode and the H-mode,which is related to the difference of the electron density and energy for the two modes.The emission intensities of Ar 750.4 nm and O 844.6 nm monotonously decrease with increasing the pressure or the O2 content,indicating that the density of high-energy electrons,which can excite atoms,is monotonically decreased.This leads to an increase of the negative ion density in the H-mode with increasing the pressure.Besides,as the applied power is increased,the electronegativity shows an abrupt drop during the E-to H-mode transition.展开更多
The electronegativity and the hardness are two popular and useful theoretical descriptors of chemistry and physics successfully used by both physicists and chemists in correlating chemico-physical properties of atoms,...The electronegativity and the hardness are two popular and useful theoretical descriptors of chemistry and physics successfully used by both physicists and chemists in correlating chemico-physical properties of atoms, molecules and condensed matter physics. We have tried to explore the fundamental nature of the hardness and electronegativity of atoms and have observed that their fundamental nature is basically lying in electrostatics and manifest as the electron attracting power emanating from the nucleus of the atom. We have tried to correlate the periodic nature of variation of the electronegativity and the hardness to the electron attracting power of the nucleus from which they are originated and developed. We have developed the formulae for evaluating both electronegativity and hardness and found that they have the direct correlation with the effective nuclear charge of the atoms and hence their periodicity.展开更多
Atoms in most organic molecules are often carbon,oxygen,nitrogen,sulfur,halogens,etc. Based on the three-dimensional structure of a molecule,a molecular structural characterization（MSC） method called improved molecu...Atoms in most organic molecules are often carbon,oxygen,nitrogen,sulfur,halogens,etc. Based on the three-dimensional structure of a molecule,a molecular structural characterization（MSC） method called improved molecular electronegativity-distance vector（I-MEDV） was developed. It was used to describe the structures of 37 compounds of styrax japonicus sieb flowers. Through multiple linear regression（MLR）,a QSRR model was built up. The correlation coefficient（R1） of the model was 0.980. Then,4 vectors were selected to build another model through the method of stepwise multiple regression（SMR） ,and the correlation coefficient（R2） of the model was 0.975. Moreover,all the two models were evaluated by performing the crossvalidation with the leave-one-out（LOO） procedure and the correlation coefficients（Rcv） were 0.948 and 0.968,respectively. The results show that the I-MEDV could successfully describe the structures of organic compounds. The stability and predictability of the models were good.展开更多
Ferroelectric materials are gaining increasing attention for the development of advanced catalytic technologies due to their field-responsive polarization states.However,achieving dynamic optimization of catalytic act...Ferroelectric materials are gaining increasing attention for the development of advanced catalytic technologies due to their field-responsive polarization states.However,achieving dynamic optimization of catalytic activity using ferroelectrics remains a fundamental challenge.Inspired by the force-adaptive mechanisms of fish scales,we introduce an intracrystalline force regulation strategy to dynamically control cobalt spin states and enhance peroxymonosulfate(PMS)activation in Fenton-like processes.This approach utilizes BaTi_(0.92)Co_(0.08)O_(3-δ)(BTC-8)nano-ferroelectrics,where ultrasound irradiation generates a built-in electric field that drives electrons towards cobalt sites.This electron transfer is further facilitated by electronegativity differences between cobalt and barium/titanium ions.The resulting piezo-driven electron flow promotes continuous regeneration of high-spin Co^(2+),enhancing PMS adsorption and SO_(4)^(-)-OH bond cleavage,leading to increased production of⋅SO_(4)^(-)and singlet oxygen(^(1)O_(2))for organic pollutant degradation.Consequently,BTC-8 achieves a reaction rate(k=1.7960 min^(-1))28.93 times higher than that of pure barium titanate,surpassing previously reported PMS activation and piezocatalytic systems.This work represents a shift from static electronic structure design to dynamic electronic engineering in the development of advanced catalytic strategies for water remediation.展开更多
The scarcity and high cost of lithium resources drive the search for sustainable alternatives,positioning potassium-ion batteries(KIBs)as promising energy storage solutions due to the natural abundance and advantageou...The scarcity and high cost of lithium resources drive the search for sustainable alternatives,positioning potassium-ion batteries(KIBs)as promising energy storage solutions due to the natural abundance and advantageous electrochemical properties of the potassium.This study investigates the enhancement of KIB anodes through phase transformation and electronic structure engineering of monolayer 1T-MoS_(2),achieved via doping with highly electronegative non-metal elements:carbon(C),nitrogen(N),oxygen(O),and fluorine(F).Density functional theory(DFT)simulations reveal that electronegative atom doping enhances phase stability,structural robustness,and thermal resilience,which are key properties for highperformance KIB anodes.Among the doped configurations,F and N-doped 1T-MoS_(2)(MoS_(2-)F and MoS_(2)-N)exhibit superior electrochemical performance,showing optimal adsorption energies and significantly improved electronic conductivity,attributable to favorable charge redistribution and increased active potassium adsorption sites.Specifically,MoS_(2)-F and MoS_(2)-N achieve the highest specific capacities of339.65 and 339.17 mAh/g,respectively,while maintaining stability within an ideal open circuit voltage range,outperforming undoped MoS_(2).This work undersco res the potential of electronegative atom doping in 1T-MoS_(2)to enable sustainable,high-capacity energy storage solutions,offering key advancements in the electrochemical and structural properties of KIB anodes.展开更多
基金supported by the Beijing Institute of Technology Research Fund Program for Young Scholars and 21C Innovation Laboratory Contemporary Amperex Technology Co.,Limited,Ninde,352100,China(21C-OP-202314)。
文摘Heteroatom doping has emerged as a powerful strategy to optimize the catalytic and adsorption abilities of electrocatalysts by regulating the electronic structure,thereby enabling the development of efficient electrocatalysts for lithium-sulfur(Li-S)batteries.However,the correlation between the properties of doped atoms and adsorptio n-catalytic ability,as well as the interconnection between adsorption strength and catalytic activity,remains underexplored.Herein,we employed halogen atoms(F,Cl,and Br)with different electronegativities to dope nickel phosphide(Ni_(2)P),aiming to modulate the adsorption properties toward lithium polysulfides(LiPSs).We systematically explored the relationship between the electronegativity of the doping atoms and the adsorption strength,followed by exploring the connection between adsorption and catalytic capabilities.Combined experimental and theoretical analyses reveal that doping halogen atoms effectively strengthens d-p orbital hybridization between Ni atoms and S atoms,thereby enhancing LiPSs anchoring and conversion.Specifically,the chemical adsorption capability is enhanced as the electronegativity of the doped atoms increases.Moreover,the catalytic activity presents a volcano-like trend with the enhancement of adsorption performance,wherein the activity initially increases and subsequently diminishes.Therefore,Cl-doped Ni_(2)P with moderate chemisorption ability exhibits optimal redox kinetics in bidirectional sulfur conversion.Consequently,the Li-S batteries with Cl-Ni_(2)P-separators deliver a high-rate capacity of 790 mAh g^(-1)at 5 C and achieve a remarkable areal capacity of 7.36 mAh cm^(-2)under practical conditions(sulfur loading:7.10 mg cm^(-2);electrolyte/sulfur(E/S)ratio:5μL mg^(-1)).This work uncovers the significance of achieving a balance between adsorption and catalytic capabilities,offering insights into designing efficient electrocatalysts for lithium-sulfur batteries.
文摘We take the contribution of all valence electrons into consideration and propose a new valence electrons equilibration method to calculate the equalized electronegativity including molecular electronegativity, group electronegativity, and atomic charge. The ionization potential of alkanes and mono-substituted alkanes, the chemical shift of 1H NMR, and the gas phase proton affinity of aliphatic amines, alcohols, and ethers were estimated. All the expressions have good correlations. Moreover, the Sanderson method and Bratsch method were modified on the basis of the valence electrons equilibration theory. The modified Sanderson method and modified Bratsch method are more effective than their original methods to estimate these properties.
基金the National Natural Science Foundation of China (Nos. 52071179, 52271033)the Key Program of National Natural Science Foundation of China (No. 51931003)+2 种基金the Natural Science Foundation of Jiangsu Province, China (No. BK20221493)the Jiangsu Province Leading Edge Technology Basic Research Major Project, China (No. BK20222014)the Foundation of “Qinglan Project” for Colleges and Universities in Jiangsu Province, China。
文摘The composition−property relationship of 18 quaternary high entropy diborides(HEBs)consisting of boron and IVB,VB and VIB transition metals(TM)was investigated using first-principles calculations.A valence electron concentration−relative electronegativity(VEC−REN)composite descriptor was developed to effectively predict the mechanical properties of HEBs.The results demonstrate that with a fixed VEC,the rise of the REN makes HEBs harder but more brittle when the electronegativity of doped TM atoms is lower than that of boron atoms.However,HEBs become softer and more ductile as REN increases if the doped TM atoms have higher electronegativity than boron atoms.The VEC−REN composite descriptor can accurately classify and predict the mechanical properties of HEBs with different components,which provides important theoretical guidance for the rapid design and development of novel high-entropy ceramic materials.
基金supported by National Natural Science Foundation of China (No.51337006)
文摘The density distributions related to gas electronegativity for c-C4Fs gas, including negative ion, electron number and electron energy densities in the discharge process, are derived theoretically in both plane-to-plane and point-to-plane electrode geometries. These calculations have been performed through the Boltzmann equation in the condition of a steady-state Townsend （SST） experiment and a fluid model in the condition of both uniform and non-uniform electric fields. The electronegativity coefficients a = n-/ne of c-C4Fs and SF6 are compared to further describe the electron affinity of c-C4Fs. The result shows that c-C4Fs represents an obvious electron-attachment performance in the discharge process. However, c-C4Fs still has much weaker gas electronegativity than SF6, whose electronegativity coefficient is lower than that of SF6 by at least three orders of magnitude.
基金the National Natural Science Foundation of China(Nos.51473156 and 51873203)Key Projects of Jilin Province Science and Technology Development Plan(Nos.2018020108GX and 20160204028GX)
文摘Rare earth catalysts possessing characteristics of cation-anion ion pair show advantages of adjusting electronegativity and steric hindrance of metal active sites, which can control the catalytic performance and stereoselectivity better than those of traditional metallocene and Ziegler-Natta catalysts in diene polymerization. In this work, a series of neodymium organic sulfonate complexes,Nd(CF_3SO_3)_3·x H_2O·y L(x, y: the coordination number; L refers to an organic electron donating ligand, such as acetylacetone(acac), isooctyl alcohol(IAOH), tributyl phosphate(TBP), etc.), have been synthesized to form the cationic active species in the presence of alkylaluminum such as Al(i-Bu)_3, AlEt_3, and Al(i-Bu)_2H, which display high activities and distinguishing cis-1,4 selectivities(up to99.9%) for the polymerization of butadiene. The microstructures, yield, molecular weight, and molecular weight distribution of the resulting polymer are well controlled by adjusting electronegativity/steric hindrance of the complexes. In addition, the kinetics, active species, and the possible process of polymerization are also discussed in this article.
基金supported by the National Natural Science Foundation of China(No.21773238)the Fundamental Research Funds of Shandong University(2019GN025)。
文摘Excited-state intramolecular proton transfer(ESIPT)is favored by researchers because of its unique optical properties.However,there are relatively few systematic studies on the effects of changing the electronegativity of atoms on the ESIPT process and photophysical properties.Therefore,we selected a series of benzoxazole isothiocyanate fluorescent dyes(2-HOB,2-HSB,and 2-HSe B)by theoretical methods,and systematically studied the ESIPT process and photophysical properties by changing the electronegativity of chalcogen atoms.The calculated bond angle,bond length,energy gap,and infrared spectrum analysis show that the order of the strength of intramolecular hydrogen bonding of the three molecules is 2-HOB<2-HSB<2-HSe B.Correspondingly,the magnitude of the energy barrier of the potential energy curve is 2-HOB>2-HSB>2-HSe B.In addition,the calculated electronic spectrum shows that as the atomic electronegativity decreases,the emission spectrum has a redshift.Therefore,this work will offer certain theoretical guidance for the synthesis and application of new dyes based on ESIPT properties.
基金supported by the foundation of project DUT19LK59
文摘One of the novel phenomena of Ar/O_(2)inductively coupled plasma,the delta negative ions density profile is discovered by the fluid simulation at very low electronegativity.The anions delta is found to be formed by the collaboration of successive plasma transport phases.The plasma transport itself is affected by the delta,exhibiting many new phenomena.A new type of Helmholtz equation is devised to mathematically explain the delta forming mechanism.For revealing the physics behind,a revised spring oscillator dynamic equation has been constructed according to the Helmholtz equation,in a relevant paper[Zhao S X and Li J Z(2021)Chin.Phys.B 30055202].The investigation about the anions delta distribution is a nice prediction of new phenomenon in low temperature electronegative plasmas,waiting for the validation of related experiments.
基金supported by the Foundation of Returned Scholars (Main Program) of Shanxi Province (200902)
文摘Polychlorinated dibenzothiophenes（PCDTs） are classified as persistent organic pollutants in the environment,so the analysis of PCDTs by their gas chromatographic behaviors is of great significance.Quantitative structure-retention relationship（QSRR） analysis is a useful technique capable of relating chromatographic retention time to the molecular structure.In this paper,a QSRR study of 37 PCDTs was carried out by using molecular electronegativity distance vector（MEDV） descriptors and multiple linear regression（MLR） and partial least-squares regression（PLS） methods.The correlation coefficient R of established MLR,PLS models,leave-one-out（LOO） cross-validation（CV）,Q2ext were 0.9951,0.9942,0.9839（MLR） and 0.9925,0.9915,0.9833（PLS）,respectively.Results showed that the model exhibited excellent estimate capability for internal sample set and good predictive capability for external sample set.By using MEDV descriptors,the QSRR model can provide a simple and rapid way to predict the gas-chromatographic retention indices of polychlorinated dibenzothiophenes in conditions of lacking standard samples or poor experimental conditions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11675039,11875101,and 11935005)the Fundamental Research Founds for the Central Universities,China(Grant Nos.DUT18TD06 and DUT20LAB201).
文摘This paper presents the evolution of the electronegativity with the applied power during the E to H mode transition in a radio frequency(rf)inductively coupled plasma(ICP)in a mixture of Ar and O2.The densities of the negative ion and the electron,as well as their ratio,i.e.,the electronegativity,are measured as a function of the applied power by laser photo-detachment combined with a microwave resonance probe,under different pressures and O2 contents.Meanwhile,the optical emission intensities at Ar 750.4 nm and O 844.6 nm are monitored via a spectrograph.It was found that by increasing the applied power,the electron density and the optical emission intensity show a similar trench,i.e.,they increase abruptly at a threshold power,suggesting that the E to H mode transition occurs.With the increase of the pressure,the negative ion density presents opposite trends in the E-mode and the H-mode,which is related to the difference of the electron density and energy for the two modes.The emission intensities of Ar 750.4 nm and O 844.6 nm monotonously decrease with increasing the pressure or the O2 content,indicating that the density of high-energy electrons,which can excite atoms,is monotonically decreased.This leads to an increase of the negative ion density in the H-mode with increasing the pressure.Besides,as the applied power is increased,the electronegativity shows an abrupt drop during the E-to H-mode transition.
文摘The electronegativity and the hardness are two popular and useful theoretical descriptors of chemistry and physics successfully used by both physicists and chemists in correlating chemico-physical properties of atoms, molecules and condensed matter physics. We have tried to explore the fundamental nature of the hardness and electronegativity of atoms and have observed that their fundamental nature is basically lying in electrostatics and manifest as the electron attracting power emanating from the nucleus of the atom. We have tried to correlate the periodic nature of variation of the electronegativity and the hardness to the electron attracting power of the nucleus from which they are originated and developed. We have developed the formulae for evaluating both electronegativity and hardness and found that they have the direct correlation with the effective nuclear charge of the atoms and hence their periodicity.
基金supported by the Youth Foundation of Education Bureau,Sichuan Province (09ZB036)Technology Bureau,Sichuan Province (2006j13-141)
文摘Atoms in most organic molecules are often carbon,oxygen,nitrogen,sulfur,halogens,etc. Based on the three-dimensional structure of a molecule,a molecular structural characterization（MSC） method called improved molecular electronegativity-distance vector（I-MEDV） was developed. It was used to describe the structures of 37 compounds of styrax japonicus sieb flowers. Through multiple linear regression（MLR）,a QSRR model was built up. The correlation coefficient（R1） of the model was 0.980. Then,4 vectors were selected to build another model through the method of stepwise multiple regression（SMR） ,and the correlation coefficient（R2） of the model was 0.975. Moreover,all the two models were evaluated by performing the crossvalidation with the leave-one-out（LOO） procedure and the correlation coefficients（Rcv） were 0.948 and 0.968,respectively. The results show that the I-MEDV could successfully describe the structures of organic compounds. The stability and predictability of the models were good.
基金the National Natural Science Foundation of China(Grant No.U2002217,52102342,52103024 and 12404116)Key Research Program of the Chinese Academy of Sciences(Grant No.ZDRW-CN2021-3-1-18)+5 种基金Chenguang Program of Shanghai Education Development Foundation,Shanghai Municipal Education Commission(Grant No.21CGA40)9th Young Elite Scientists Sponsorship Program by CAST(Grant No.2023QNRC001)10th Young Elite Scientists Sponsorship Program by CAST(Grant No.YESS20240270)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20232832)Donghua University 2024 Cultivation Project of Discipline Innovation(Grant No.xkcx-202413)Student Training Program for Innovation and Entrepreneurship of Hangzhou Institute for Advanced Study,University of Chinese Academy of Sciences(Grant No.CXCY20230305).
文摘Ferroelectric materials are gaining increasing attention for the development of advanced catalytic technologies due to their field-responsive polarization states.However,achieving dynamic optimization of catalytic activity using ferroelectrics remains a fundamental challenge.Inspired by the force-adaptive mechanisms of fish scales,we introduce an intracrystalline force regulation strategy to dynamically control cobalt spin states and enhance peroxymonosulfate(PMS)activation in Fenton-like processes.This approach utilizes BaTi_(0.92)Co_(0.08)O_(3-δ)(BTC-8)nano-ferroelectrics,where ultrasound irradiation generates a built-in electric field that drives electrons towards cobalt sites.This electron transfer is further facilitated by electronegativity differences between cobalt and barium/titanium ions.The resulting piezo-driven electron flow promotes continuous regeneration of high-spin Co^(2+),enhancing PMS adsorption and SO_(4)^(-)-OH bond cleavage,leading to increased production of⋅SO_(4)^(-)and singlet oxygen(^(1)O_(2))for organic pollutant degradation.Consequently,BTC-8 achieves a reaction rate(k=1.7960 min^(-1))28.93 times higher than that of pure barium titanate,surpassing previously reported PMS activation and piezocatalytic systems.This work represents a shift from static electronic structure design to dynamic electronic engineering in the development of advanced catalytic strategies for water remediation.
基金financial support provided by the NORPART-2021/10355 project,funded by the Norwegian Directorate for Higher Education and Skills(HK-Dir)。
文摘The scarcity and high cost of lithium resources drive the search for sustainable alternatives,positioning potassium-ion batteries(KIBs)as promising energy storage solutions due to the natural abundance and advantageous electrochemical properties of the potassium.This study investigates the enhancement of KIB anodes through phase transformation and electronic structure engineering of monolayer 1T-MoS_(2),achieved via doping with highly electronegative non-metal elements:carbon(C),nitrogen(N),oxygen(O),and fluorine(F).Density functional theory(DFT)simulations reveal that electronegative atom doping enhances phase stability,structural robustness,and thermal resilience,which are key properties for highperformance KIB anodes.Among the doped configurations,F and N-doped 1T-MoS_(2)(MoS_(2-)F and MoS_(2)-N)exhibit superior electrochemical performance,showing optimal adsorption energies and significantly improved electronic conductivity,attributable to favorable charge redistribution and increased active potassium adsorption sites.Specifically,MoS_(2)-F and MoS_(2)-N achieve the highest specific capacities of339.65 and 339.17 mAh/g,respectively,while maintaining stability within an ideal open circuit voltage range,outperforming undoped MoS_(2).This work undersco res the potential of electronegative atom doping in 1T-MoS_(2)to enable sustainable,high-capacity energy storage solutions,offering key advancements in the electrochemical and structural properties of KIB anodes.
