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
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.
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
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.
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.
