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
The absorption spectra and the refractive index changes are calculated theoretically for an exeiton in a core/shell quantum dot. The advantage of our methodology is that one can investigate the influence of the repuls...The absorption spectra and the refractive index changes are calculated theoretically for an exeiton in a core/shell quantum dot. The advantage of our methodology is that one can investigate the influence of the repulsive core by varying two parameters in the confinement potential. The dimensionality effect of exciton quantum dots on the optical absorptions has been studied. It has been found that in the same regime, the optical absorption intensities of excitons axe much smaller for the core/shell quantum dots than for the two-dimensional quantum rings. The linear and the nonlinear optical absorption coefficients and refractive index changes have been examined with the change of the confinement potential. The results show that the optical absorptions and the refractive index changes are strongly affected by the repulsive core of core/shell quantum dots. Moreover, the calculated results also reveal that as the inner radius increases, the peak values of the absorption coefficients and the refractive index changes of an exciton will show the optical Aharonov-Bohm oscillation in core/shell quantum dots.展开更多
Objective:To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods:...Objective:To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods: We examined changes in cellular morphology and membrane fluidity of LNCaP cells, distribution of cellular zinc, and the incorporated portion of EGCG after treatments with EGCG, Zn2+, and EGCG+Zn2+. Results: We observed an alteration in cellular morphology and a decrease in membrane fluidity of LNCaP cells after treatment with EGCG or Zn2+. The proportion of EGCG incorporated into liposomes treated with the mixture of EGCG and Zn2+ at the ratio of 1:1 was 90.57%, which was significantly higher than that treated with EGCG alone (30.33%). Electron spin resonance (ESR) studies and determination of fatty acids showed that the effects of EGCG on the membrane fluidity of LNCaP were decreased by Zn2+. EGCG accelerated the accumulation of zinc in the mitochondria and cytosol as observed by atomic absorption spectrometer. Conclusion: These results show that EGCG interacted with cell membrane, decreased the membrane fluidity of LNCaP cells, and accelerated zinc accumulation in the mitochondria and cytosol, which could be the mechanism by which EGCG inhibits proliferation of LNCaP cells. In addition, high concentrations of Zn2+ could attenuate the actions elicited by EGCG.展开更多
Scanning the absorption spectral line of water vapor through wavelength around 1368.597nm is successfully used to measure the value of micro-moisture content. The synchronous superposition average of original signal a...Scanning the absorption spectral line of water vapor through wavelength around 1368.597nm is successfully used to measure the value of micro-moisture content. The synchronous superposition average of original signal algorithm based on labview is innovated and applied to detecting weak spectrum absorption signal instead of low pass filter. Two data processing methods are used to get the concentration of water vapor in ppm： one is a general formula method which has newly deduced a general formula to calculate the concentration of gas with temperature and beam intensity ratio when the pressure is equal to or greater than 1 atm; the other is engineering calibration method which is proved to have high resolution and accuracy with the fitted curve of beam intensity ratio and concentration in ppm when the temperature changes form 258K to 305K and the pressure ranges from 1 atm to 5 atm.展开更多
基金ACKNOWLEDGMENTS This work was supported by Young Scientists Fund of the National Natural Science Foundation of China （No.10904085）.
文摘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.
文摘The absorption spectra and the refractive index changes are calculated theoretically for an exeiton in a core/shell quantum dot. The advantage of our methodology is that one can investigate the influence of the repulsive core by varying two parameters in the confinement potential. The dimensionality effect of exciton quantum dots on the optical absorptions has been studied. It has been found that in the same regime, the optical absorption intensities of excitons axe much smaller for the core/shell quantum dots than for the two-dimensional quantum rings. The linear and the nonlinear optical absorption coefficients and refractive index changes have been examined with the change of the confinement potential. The results show that the optical absorptions and the refractive index changes are strongly affected by the repulsive core of core/shell quantum dots. Moreover, the calculated results also reveal that as the inner radius increases, the peak values of the absorption coefficients and the refractive index changes of an exciton will show the optical Aharonov-Bohm oscillation in core/shell quantum dots.
基金Project (No. 30470198) supported by the National Natural Science Foundation of China
文摘Objective:To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods: We examined changes in cellular morphology and membrane fluidity of LNCaP cells, distribution of cellular zinc, and the incorporated portion of EGCG after treatments with EGCG, Zn2+, and EGCG+Zn2+. Results: We observed an alteration in cellular morphology and a decrease in membrane fluidity of LNCaP cells after treatment with EGCG or Zn2+. The proportion of EGCG incorporated into liposomes treated with the mixture of EGCG and Zn2+ at the ratio of 1:1 was 90.57%, which was significantly higher than that treated with EGCG alone (30.33%). Electron spin resonance (ESR) studies and determination of fatty acids showed that the effects of EGCG on the membrane fluidity of LNCaP were decreased by Zn2+. EGCG accelerated the accumulation of zinc in the mitochondria and cytosol as observed by atomic absorption spectrometer. Conclusion: These results show that EGCG interacted with cell membrane, decreased the membrane fluidity of LNCaP cells, and accelerated zinc accumulation in the mitochondria and cytosol, which could be the mechanism by which EGCG inhibits proliferation of LNCaP cells. In addition, high concentrations of Zn2+ could attenuate the actions elicited by EGCG.
基金This work was supported by Natural Science Foundation of China （60977058）, Science Fund for Distinguished Young Scholars of Shandong Province of China （JQ200819）, Research Award Fund for Outstanding Middle-aged＇ and Young Scientist of Shandong Province of China （2007BS08003）, Independent Innovation Foundation of Shandong University （IIFSDU2010JC002）.
文摘Scanning the absorption spectral line of water vapor through wavelength around 1368.597nm is successfully used to measure the value of micro-moisture content. The synchronous superposition average of original signal algorithm based on labview is innovated and applied to detecting weak spectrum absorption signal instead of low pass filter. Two data processing methods are used to get the concentration of water vapor in ppm： one is a general formula method which has newly deduced a general formula to calculate the concentration of gas with temperature and beam intensity ratio when the pressure is equal to or greater than 1 atm; the other is engineering calibration method which is proved to have high resolution and accuracy with the fitted curve of beam intensity ratio and concentration in ppm when the temperature changes form 258K to 305K and the pressure ranges from 1 atm to 5 atm.
