Electronic, elastic and piezoelectric properties of two-dimensional （2D） group-IV buckled monolayers （GeSi, SnSi and SnGe） are studied by first principle calculations. According to our calculations, SnSi and SnGe ...Electronic, elastic and piezoelectric properties of two-dimensional （2D） group-IV buckled monolayers （GeSi, SnSi and SnGe） are studied by first principle calculations. According to our calculations, SnSi and SnGe are good 2D piezoelectric materials with large piezoelectric coefficients. The values of d11d11 of SnSi and SnGe are 5.04pm/V and 5.42pm/V, respectively, which are much larger than 2D MoS2 （3.6pm/V） and are comparable with some frequently used bulk materials （e.g., wurtzite AlN 5.1pm/V）. Charge transfer is calculated by the L wdin analysis and we find that the piezoelectric coefficients （d11d11 and d31） are highly dependent on the polarizabilities of the anions and cations in group-IV monolayers.展开更多
The space group of PrCo_(12)B_6,compound has been determined using the convergent beam elec- tron diffraction method.The space group is found to be R3m.
A fair electronic cash system is a system that allows customers to make payments anonymously. Furthermore the trusted third party can revoke the anonymity when the customers did illegal transactions. In this paper, a ...A fair electronic cash system is a system that allows customers to make payments anonymously. Furthermore the trusted third party can revoke the anonymity when the customers did illegal transactions. In this paper, a new fair electronic cash system based on group signature scheme by using elliptic curve cryptography is proposed, which satisfies properties of secure group signature scheme (correctness, unforgeability, etc). Moreover, our electronic cash contains group members (users, merchants and banks) and trusted third party which is acted by central bank as group manager.展开更多
The Xinxing Electronics Group was jointly established by several stateowned electronic enterprises lacking in technical base in Zibo, Shandong Province, in 1994. The year 1996 saw the Group realizing sales income of R...The Xinxing Electronics Group was jointly established by several stateowned electronic enterprises lacking in technical base in Zibo, Shandong Province, in 1994. The year 1996 saw the Group realizing sales income of RMB80 million and pre-tax profits of RMB25 million. According to market forecasts, sales income of RMB300 million展开更多
The physical trend of group-I/tellurides is unexpected and contrary to the conventional wisdom. The present firstprinciples calculations give fundamental insights into the extent to which group-Ⅱ telluride compounds ...The physical trend of group-I/tellurides is unexpected and contrary to the conventional wisdom. The present firstprinciples calculations give fundamental insights into the extent to which group-Ⅱ telluride compounds present special properties upon mixing the d valence character. Our results provide explanations for the unexpected experimental observations based on the abnormal binding ordering of metal d electrons and their strong perturbation to the band edge states. The insights into the binary tellurides are useful for the study and control of the structural and chemical perturbation in their ternary alloys and heterostructures.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 structural, electronic, mechanical, and thermal properties of Pt, Pd, Rh, Ir, Os metals and their alloys PtPdX （X = Ir, Os and Rh） are studied systematically using ab initio density functional theory. The ground...The structural, electronic, mechanical, and thermal properties of Pt, Pd, Rh, Ir, Os metals and their alloys PtPdX （X = Ir, Os and Rh） are studied systematically using ab initio density functional theory. The groundstate properties such as lattice constant and bulk modulus are calculated to find the equilibrium atomic position for stable alloys. The electronic band structure and density of states are calculated to study the electronic behavior of metals on making their alloys. The electronic properties substantiate the metallic behavior for all studied materials. The firstprinciples density functional perturbation theory as implemented in quasi-harmonic approximation is used for the calculations of thermal properties. We have calculated the thermal properties such as the Debye temperature, vibrational energy, entropy and constant-volume specific heat. The calculated properties are compared with the previously reported experimental and theoretical data for metals and are found to be in good agreement. Calculated results for alloys could not be compared because there is no data available in the literature with such alloy composition.展开更多
Organic electrode materials have high capacity,and environmentally friendly advantages for the next generation lithium-ion batteries(LIBs).However,organic electrode materials face many challenges,such as low reduction...Organic electrode materials have high capacity,and environmentally friendly advantages for the next generation lithium-ion batteries(LIBs).However,organic electrode materials face many challenges,such as low reduction potential as cathode materials or high reduction potential as anode materials.Here,the influence of chemical functionalities that are capable of either electron donating or electron withdrawing groups on the reduction potential and charge-discharge performance of anthraquinone(AQ)based system is studied.The cyclic voltammetry results show that the introduction of two-OH groups,two-NO2 groups and one-CH3 group on anthraquinone structure has a little impact on the reduction potential,which is found to be 2.1 V.But when three or four-OH groups are introduced on AQ structure,the reduction potential is increased to about 3.1 V.The charge-discharge tests show that these materials exhibit moderate cycling stability.展开更多
New electron donors with hydroxyl groups were synthesized and characterized spectroscopically. Their redox potentials were determined with cyclic voltammetry, and the comparison with BEDT-TTF [Bis(ethylenedithio)tetra...New electron donors with hydroxyl groups were synthesized and characterized spectroscopically. Their redox potentials were determined with cyclic voltammetry, and the comparison with BEDT-TTF [Bis(ethylenedithio)tetrathiafulvalene] in this aspect was made. These results indicated that the new electron donors had similar electron-donating capabilities as BEDT-TTF.展开更多
This paper describes the research results and development of fair off-line e-cash systems so far, and points out that in these systems, the bank can compute the double-spender’s account secret key, thus the bank can ...This paper describes the research results and development of fair off-line e-cash systems so far, and points out that in these systems, the bank can compute the double-spender’s account secret key, thus the bank can impersonate the double-spender to withdraw from the double-spender’s account. This article utilizes anonymity control and group signature to address this shortcoming. Key words electronic cash - anonymity control - group signature CLC number TP 309 Foundation item: Supported by the National Natural Science Fundation of China (90204015)Biography: SU Yun-xue (1975-), male, Ph. D. research direction: the software and theory of computer and information security.展开更多
MXenes are a new type of two-dimensional carbides with rich physical and chemical properties. The physics of MXenes, and thus the applications, are dominated by surface functional groups. Herein, the effects of differ...MXenes are a new type of two-dimensional carbides with rich physical and chemical properties. The physics of MXenes, and thus the applications, are dominated by surface functional groups. Herein, the effects of different terminations(O,S, Se, Te) on the geometric and electronic properties of Nb_(2)C MXenes were studied via density functional theory(DFT)calculations. Three adsorption sites were examined to determine the most stable configurations. The results showed that both the types and the positions of surface functional groups influence the geometric stability and physical characters of Nb_(2)C. The S and Se terminations make the Nb_(2)C MXenes to be semiconductor, while Nb_(2)C MXenes with other terminations(O, Te) are conductor. The electron location function, density of states, Bader charge distribution, and the projected crystal orbital Hamilton population were conducted to explain the origin of adsorption stability and electronic nature difference. Our results provide a fundamental understanding about the effects of surface terminations on the intrinsic stability and electronic properties of Nb_(2)C MXenes.展开更多
With the right and the left waves of an electron, plus the left wave of its neutrino, we write the tensorial densities coming from all associations of these three spinors. We recover the wave equation of the electro-w...With the right and the left waves of an electron, plus the left wave of its neutrino, we write the tensorial densities coming from all associations of these three spinors. We recover the wave equation of the electro-weak theory. A new non linear mass term comes out. The wave equation is form invariant, then relativistic invariant, and it is gauge invariant under the U(1)×SU(2), Lie group of electro-weak interactions. The invariant form of the wave equation has the Lagrangian density as real scalar part. One of the real equations equivalent to the invariant form is the law of conservation of the total current.展开更多
This paper mainly analysis of group buying website based on O2O model. This new e-business model which has great development potential attracted many entrepreneurs. The related theories of network group-buying model w...This paper mainly analysis of group buying website based on O2O model. This new e-business model which has great development potential attracted many entrepreneurs. The related theories of network group-buying model were collected. The problems existed in this new e-business model were discussed and analyzed with professional management knowledge. Corresponding suggestions and measures were also given.展开更多
The change and development of the environment of electronic commerce has a great influence on enterprises and consumers. The characteristics of the consumer behavior is changing,the marketing mode of enterprise, espec...The change and development of the environment of electronic commerce has a great influence on enterprises and consumers. The characteristics of the consumer behavior is changing,the marketing mode of enterprise, especially network marketing, is gradually affected. This paper analyzes the challenges faced by the production and operation activities of traditional enterprise,the changes of consumer behavior, and some problems and countermeasures in network marketing.展开更多
Poly(methyltetraphenylphenylsilylene-co-bis(methylphenylsilyl)acetylene) (PSA) was synthesized by the cocondensation reaction of methyltetraphenylphenyldichlorosilane and bis(chloromethylphenylsilyl)acetylene with sod...Poly(methyltetraphenylphenylsilylene-co-bis(methylphenylsilyl)acetylene) (PSA) was synthesized by the cocondensation reaction of methyltetraphenylphenyldichlorosilane and bis(chloromethylphenylsilyl)acetylene with sodium in toluene. The PSA thus obtained was soluble in most organic solvents, and its molecular weight was smaller than that of poly[(disilanylene)acetylenes] with alkyl- or aryl-substitution because of the great steric congestion of tetraphenylphenyl groups. The optical and electronic properties of the polymer were investigated. The results show that PSA has strong UV absorption and fluorescence emission, the maximum UV absorption wavelength of PSA is 330 nm, which shows a considerable red-shift in comparison with that of poly(methylphenylsilylene-co-methylphenylsilylacetylene) (PSI) and alkyl- substituted poly[(disilanylene)acetylenes]. A strong photoluminescence band at 470 nm in THF and 432 nm in benzene can be observed in the visible region, respectively. Treatment of the films of PSA with I 2 vapor afforded conducting films. The conductivity of PSA thin film doped with I 2 was measured to be 0.35 S cm -1 in the air which is lower than that of poly(methyltetraphenylphenylsilylene-co-bis(methylphenylsilyl)phenylene), but higher than that of σ-π polymers without tetraphenylphenyl groups. As an explanation, the tetraphenylphenyl group is a large π-electron-conjugated group; after being introduced to the Si atoms of the polysilanes, the interaction between π-electrons of the tetraphenylphenyl groups and the σ- electrons conjugated along the Si—Si bonds is increased strongly, and the σ-electrons can be conjugated more extensively along the main chain of the polysilanes.展开更多
In 2019,the Atomic&Molecular Spectroscopy Group made progresses on development of Momentum Com-puted Tomography(MCT),theoretical investigation of Two-Electron-One-Photon(TEOP)processes,and other researches.
基金Supported by the National Natural Science Foundation of China under Grant No 51672208the National Science and Technology Pillar Program during the Twelfth Five-Year Plan Period under Grant No 2012BAD47B02+2 种基金the Sci-Tech Research and Development Program of Shaanxi Province under Grant Nos 2010K01-120,2011JM6010 and 2015JM5183the Shaanxi Provincial Department of Education under Grant No 2013JK0927the SRF for ROCS of SEM
文摘Electronic, elastic and piezoelectric properties of two-dimensional （2D） group-IV buckled monolayers （GeSi, SnSi and SnGe） are studied by first principle calculations. According to our calculations, SnSi and SnGe are good 2D piezoelectric materials with large piezoelectric coefficients. The values of d11d11 of SnSi and SnGe are 5.04pm/V and 5.42pm/V, respectively, which are much larger than 2D MoS2 （3.6pm/V） and are comparable with some frequently used bulk materials （e.g., wurtzite AlN 5.1pm/V）. Charge transfer is calculated by the L wdin analysis and we find that the piezoelectric coefficients （d11d11 and d31） are highly dependent on the polarizabilities of the anions and cations in group-IV monolayers.
文摘The space group of PrCo_(12)B_6,compound has been determined using the convergent beam elec- tron diffraction method.The space group is found to be R3m.
文摘A fair electronic cash system is a system that allows customers to make payments anonymously. Furthermore the trusted third party can revoke the anonymity when the customers did illegal transactions. In this paper, a new fair electronic cash system based on group signature scheme by using elliptic curve cryptography is proposed, which satisfies properties of secure group signature scheme (correctness, unforgeability, etc). Moreover, our electronic cash contains group members (users, merchants and banks) and trusted third party which is acted by central bank as group manager.
文摘The Xinxing Electronics Group was jointly established by several stateowned electronic enterprises lacking in technical base in Zibo, Shandong Province, in 1994. The year 1996 saw the Group realizing sales income of RMB80 million and pre-tax profits of RMB25 million. According to market forecasts, sales income of RMB300 million
基金supported by the National Natural Science Foundation of China (Grant Nos. 10847111 and 61006091)the Startup Project for Ph. D. of Guangdong University of Technology (Grant No. 083034)the Fundamental Research Funds for the Central Universities of South China University of Technology (Grant No. 2009ZM0022)
文摘The physical trend of group-I/tellurides is unexpected and contrary to the conventional wisdom. The present firstprinciples calculations give fundamental insights into the extent to which group-Ⅱ telluride compounds present special properties upon mixing the d valence character. Our results provide explanations for the unexpected experimental observations based on the abnormal binding ordering of metal d electrons and their strong perturbation to the band edge states. The insights into the binary tellurides are useful for the study and control of the structural and chemical perturbation in their ternary alloys and heterostructures.
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.
文摘The structural, electronic, mechanical, and thermal properties of Pt, Pd, Rh, Ir, Os metals and their alloys PtPdX （X = Ir, Os and Rh） are studied systematically using ab initio density functional theory. The groundstate properties such as lattice constant and bulk modulus are calculated to find the equilibrium atomic position for stable alloys. The electronic band structure and density of states are calculated to study the electronic behavior of metals on making their alloys. The electronic properties substantiate the metallic behavior for all studied materials. The firstprinciples density functional perturbation theory as implemented in quasi-harmonic approximation is used for the calculations of thermal properties. We have calculated the thermal properties such as the Debye temperature, vibrational energy, entropy and constant-volume specific heat. The calculated properties are compared with the previously reported experimental and theoretical data for metals and are found to be in good agreement. Calculated results for alloys could not be compared because there is no data available in the literature with such alloy composition.
基金Project(21875076)supported by the National Natural Science Foundation of ChinaProjects(2018A050506077,2017A050506048)supported by the Scientific and Technological Plan of Guangdong Province,ChinaProject(201910574037)supported by the Undergraduates’ Innovating Experimentation Project of China
文摘Organic electrode materials have high capacity,and environmentally friendly advantages for the next generation lithium-ion batteries(LIBs).However,organic electrode materials face many challenges,such as low reduction potential as cathode materials or high reduction potential as anode materials.Here,the influence of chemical functionalities that are capable of either electron donating or electron withdrawing groups on the reduction potential and charge-discharge performance of anthraquinone(AQ)based system is studied.The cyclic voltammetry results show that the introduction of two-OH groups,two-NO2 groups and one-CH3 group on anthraquinone structure has a little impact on the reduction potential,which is found to be 2.1 V.But when three or four-OH groups are introduced on AQ structure,the reduction potential is increased to about 3.1 V.The charge-discharge tests show that these materials exhibit moderate cycling stability.
基金the Chinese Academy of Sciences(KJ951-A1-501-03)
文摘New electron donors with hydroxyl groups were synthesized and characterized spectroscopically. Their redox potentials were determined with cyclic voltammetry, and the comparison with BEDT-TTF [Bis(ethylenedithio)tetrathiafulvalene] in this aspect was made. These results indicated that the new electron donors had similar electron-donating capabilities as BEDT-TTF.
文摘This paper describes the research results and development of fair off-line e-cash systems so far, and points out that in these systems, the bank can compute the double-spender’s account secret key, thus the bank can impersonate the double-spender to withdraw from the double-spender’s account. This article utilizes anonymity control and group signature to address this shortcoming. Key words electronic cash - anonymity control - group signature CLC number TP 309 Foundation item: Supported by the National Natural Science Fundation of China (90204015)Biography: SU Yun-xue (1975-), male, Ph. D. research direction: the software and theory of computer and information security.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. U1804130, U2004212, 11904084, and 11874141)the Henan Overseas Expertise Introduction Center for Discipline Innovation (Grant No. CXJD2019005)+1 种基金the China Postdoctoral Science Foundation (Grant No. 2021M690933)the Key Scientific Research Projects of Henan Education Department, China (Grant No. 22A140020)。
文摘MXenes are a new type of two-dimensional carbides with rich physical and chemical properties. The physics of MXenes, and thus the applications, are dominated by surface functional groups. Herein, the effects of different terminations(O,S, Se, Te) on the geometric and electronic properties of Nb_(2)C MXenes were studied via density functional theory(DFT)calculations. Three adsorption sites were examined to determine the most stable configurations. The results showed that both the types and the positions of surface functional groups influence the geometric stability and physical characters of Nb_(2)C. The S and Se terminations make the Nb_(2)C MXenes to be semiconductor, while Nb_(2)C MXenes with other terminations(O, Te) are conductor. The electron location function, density of states, Bader charge distribution, and the projected crystal orbital Hamilton population were conducted to explain the origin of adsorption stability and electronic nature difference. Our results provide a fundamental understanding about the effects of surface terminations on the intrinsic stability and electronic properties of Nb_(2)C MXenes.
文摘With the right and the left waves of an electron, plus the left wave of its neutrino, we write the tensorial densities coming from all associations of these three spinors. We recover the wave equation of the electro-weak theory. A new non linear mass term comes out. The wave equation is form invariant, then relativistic invariant, and it is gauge invariant under the U(1)×SU(2), Lie group of electro-weak interactions. The invariant form of the wave equation has the Lagrangian density as real scalar part. One of the real equations equivalent to the invariant form is the law of conservation of the total current.
文摘This paper mainly analysis of group buying website based on O2O model. This new e-business model which has great development potential attracted many entrepreneurs. The related theories of network group-buying model were collected. The problems existed in this new e-business model were discussed and analyzed with professional management knowledge. Corresponding suggestions and measures were also given.
文摘The change and development of the environment of electronic commerce has a great influence on enterprises and consumers. The characteristics of the consumer behavior is changing,the marketing mode of enterprise, especially network marketing, is gradually affected. This paper analyzes the challenges faced by the production and operation activities of traditional enterprise,the changes of consumer behavior, and some problems and countermeasures in network marketing.
基金This work was supported by the National Natural Science Foundation of China (Project No. 29974016).
文摘Poly(methyltetraphenylphenylsilylene-co-bis(methylphenylsilyl)acetylene) (PSA) was synthesized by the cocondensation reaction of methyltetraphenylphenyldichlorosilane and bis(chloromethylphenylsilyl)acetylene with sodium in toluene. The PSA thus obtained was soluble in most organic solvents, and its molecular weight was smaller than that of poly[(disilanylene)acetylenes] with alkyl- or aryl-substitution because of the great steric congestion of tetraphenylphenyl groups. The optical and electronic properties of the polymer were investigated. The results show that PSA has strong UV absorption and fluorescence emission, the maximum UV absorption wavelength of PSA is 330 nm, which shows a considerable red-shift in comparison with that of poly(methylphenylsilylene-co-methylphenylsilylacetylene) (PSI) and alkyl- substituted poly[(disilanylene)acetylenes]. A strong photoluminescence band at 470 nm in THF and 432 nm in benzene can be observed in the visible region, respectively. Treatment of the films of PSA with I 2 vapor afforded conducting films. The conductivity of PSA thin film doped with I 2 was measured to be 0.35 S cm -1 in the air which is lower than that of poly(methyltetraphenylphenylsilylene-co-bis(methylphenylsilyl)phenylene), but higher than that of σ-π polymers without tetraphenylphenyl groups. As an explanation, the tetraphenylphenyl group is a large π-electron-conjugated group; after being introduced to the Si atoms of the polysilanes, the interaction between π-electrons of the tetraphenylphenyl groups and the σ- electrons conjugated along the Si—Si bonds is increased strongly, and the σ-electrons can be conjugated more extensively along the main chain of the polysilanes.
文摘In 2019,the Atomic&Molecular Spectroscopy Group made progresses on development of Momentum Com-puted Tomography(MCT),theoretical investigation of Two-Electron-One-Photon(TEOP)processes,and other researches.
