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Schwinger-boson approach to anisotropy ferrimagnetic chain with bond alternation
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作者 李殷翔 陈斌 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第2期409-413,共5页
We use the Schwinger-boson approach to study the anisotropy ferrimagnetic spin-(1/2,1) chain with bond alternation.Based on the effect of bond alternation δ,we obtain energy gap,free energy,and specific heat,respec... We use the Schwinger-boson approach to study the anisotropy ferrimagnetic spin-(1/2,1) chain with bond alternation.Based on the effect of bond alternation δ,we obtain energy gap,free energy,and specific heat,respectively.The specific heat with larger bond alternation(δ 〉 0.7) displays a peak at low temperature.Based on the effect of XXZ anisotropy parameter Δ,we present excited spectrums,free energy,and specific heat,respectively. 展开更多
关键词 Schwinger-boson approach bond alternation XXZ anisotropy ferrimagnetic spin chain
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Effects of Rotational Isomerism and Bond Length Alternation on Optical Spectra of FTC Chromophore in Solution
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作者 赵珂 韩广超 +1 位作者 张立立 贾海洪 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第1期75-81,I0004,共8页
Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-(4-N,N-di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)-thien-5]-E-vinylg-5,5-... Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-(4-N,N-di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)-thien-5]-E-vinylg-5,5-dimethyl-2,5-dihydrofuran (FTC) in a few solvents have been studied using the time-dependent density functional theory in combination with the polarizable continuum model. It is shown that the maximum absorption peaks of the ro-tamers have difference of nearly 30 nm both in vacuum and in solutions. The population of the rotamers changes a lot in different solvents. Based on the geometries optimized by Hartree-Fock method, the Maxwell-Boltzmann averaged absorption has been calculated and the maximum absorption peak is in good agreement with experiment. It indicates that the bond length alternation can have an important effect on the optical spectra. 展开更多
关键词 Rotational isomerism bond length alternation One-photon absorption Po-larizable continuum model
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Extraordinary mechanical performance in charged carbyne
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作者 Yong-Zhe Guo Yong-Heng Wang +2 位作者 Kai Huang Hao Yin En-Lai Gao 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第12期559-565,共7页
Carbyne,the linear chain of carbon,promises the strongest and toughest material but possesses a Peierls instability(alternating single-bonds and triple-bonds)that reduces its strength and toughness.Herein,we computati... Carbyne,the linear chain of carbon,promises the strongest and toughest material but possesses a Peierls instability(alternating single-bonds and triple-bonds)that reduces its strength and toughness.Herein,we computationally found that the gravimetric strength,strain-to-failure,and gravimetric toughness can be improved from 74 GPa·g^(-1)·cm^(3),18%,and 9.4 k J·g^(-1)for pristine carbyne to the highest values of 106 GPa·g^(-1)·cm^(3),26%,and 19.0 k J·g^(-1)for carbyne upon hole injection of+0.07 e/atom,indicating the charged carbyne with record-breaking mechanical performance.Based on the analyses of the atomic and electronic structures,the underlying mechanism behind the record-breaking mechanical performance was revealed as the suppressed and even eliminated bond alternation of carbyne upon charge injection. 展开更多
关键词 charged carbyne first-principles calculations strength and toughness bond alternation
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Effects of the structural order of canthaxanthin on the Raman scattering cross section in various solvents:A study by Raman spectroscopy and ab initio calculation 被引量:1
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作者 吴楠楠 里佐威 +1 位作者 刘靖尧 欧阳顺利 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第10期195-200,共6页
In this work,we measure the Raman scattering cross sections(RSCSs) of the carbon-carbon(CC) stretching vibrational modes of canthaxanthin in benzene,acetone,n-heptane,cyclohexane,and m-xylene.It is found that the ... In this work,we measure the Raman scattering cross sections(RSCSs) of the carbon-carbon(CC) stretching vibrational modes of canthaxanthin in benzene,acetone,n-heptane,cyclohexane,and m-xylene.It is found that the absolute RSCS of CC stretching mode of canthaxanthin reaches a value of 10 24 cm ^-2 ·molecule ^-1 ·sr ^-1 at 8×10 ^-5 M,which is 6 orders of magnitude larger than general RSCS(10 30 cm 2 ·molecule 1 ·sr 1),and the RSCSs of canthaxanthin in various solvents are very different due to the hydrogen bond.A theoretical interpretation of the magnetic experimental results is given,which is introduced in a qualitative nonlinear model of coherent weakly damped electron-lattice vibration in the structural order of polyene chains.In addition,the optimal structure and the bond length alternation(BLA) parameter of canthaxanthin are calculated using quantum chemistry calculation(at the b3lyp/6-31g(d,p) level of theory).The theoretical calculations are in good agreement with the experimental results.Furthermore,the combination of Raman spectroscopy and the quantum chemistry calculation study would be a quite suitable method of studying the structures and the properties of the π-conjugated systems. 展开更多
关键词 Raman spectroscopy the bond length alternation(BLA) parameter quantum chemistry calculation CANTHAXANTHIN
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Solvent Effects on Two-Photon Absorption of Alkyne and Alkene π-bridging Chromophores
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作者 Jing Li Chuan-kui Wang Yu-zhi Song 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2017年第1期63-70,I0001,共9页
The present work concerns the study of solvent effects on the geometrical structures, as well as one- and two-photon absorption (TPA) processes, for two series of alkyne and alkene π-bridging molecules, within the ... The present work concerns the study of solvent effects on the geometrical structures, as well as one- and two-photon absorption (TPA) processes, for two series of alkyne and alkene π-bridging molecules, within the framework of the polarization continuum model. Particular emphasis was put on the characterization of solvent effects on the molecular geometrical structures and geometric distortion, which were measured by the bond-length-alternation parameter. The π centres in the compounds are seen to play a decisive role in increasing the TPA cross section and nonlinear optical properties. All studied molecules have relatively strong TPA characteristics, while the alkyne π-bridging ones yield larger TPA cross sections. 展开更多
关键词 Nonlinear optics Two photon absorption Solvent effect Charge transfer bond length alternation
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Off-diagonal long-range order of the wave function in terms of the alternate molecular bonding geminals
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作者 吕文彩 孙家钟 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2000年第4期467-474,共8页
It is shown that in the quantum structural approach to high-Tc superconductivity, the wave function in terms of the alternate molecular bonding geminals possesses off-diagonal long-range order (ODLRO).
关键词 Alternate molecular bonding geminals quantum structural approach off-diagonal long-range order
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