Using the Dyson-Schwinger equation and perturbation theory, we calculate the mixed quark-gluon condensates in the chiral limit and in the case of nonzero quark current mass for the light quark u/d and strange quark s....Using the Dyson-Schwinger equation and perturbation theory, we calculate the mixed quark-gluon condensates in the chiral limit and in the case of nonzero quark current mass for the light quark u/d and strange quark s. The results show that the mixed quark-gluon condensate will decrease when the quark mass increases. For the quark with zero mass, we obtain mo2 = g（qσuvGuvq）/（qq） 0.68 GeV2, which is in good agreement with the QCD sum rules estimate mo2=（0.8± 0.2） GeV2.展开更多
When a boson interacts with another to form a composite system with SO（3） dynamic symmetry, it is shown that there exists the q-deformed 5osonic excitation satisfying the q-deformed Heisenberg commutation relation i...When a boson interacts with another to form a composite system with SO（3） dynamic symmetry, it is shown that there exists the q-deformed 5osonic excitation satisfying the q-deformed Heisenberg commutation relation in the quasi-classical limit that the angular momentum j for SO（3） is large, but not infinite. In second quantization this quasi-excitation is associated with the boson realization of SO（3） Lie algebra. Physically, the phenomena of q-deformed excitation can happen in many models of quantum dynamics, such as super emission from a system of many identical two-level atoms, the spin wave in Heisenberg chain, the high spin precession and the coherent output of Bose-Einstein atoms in a trap. Especially, in these models, the deformation parameter q is well defined intrinsically by a conservative quantity, such as the total atomic number and the angular momentum.展开更多
By using the dispersion theory instead of the Frohlich Hamiltonian, the polaron energy in a quantum aot with a parabolic confinement potential is investigated at finite temperatures. It is found that the self-trapping...By using the dispersion theory instead of the Frohlich Hamiltonian, the polaron energy in a quantum aot with a parabolic confinement potential is investigated at finite temperatures. It is found that the self-trapping energy of the polaron decreases with the increasing temperature, and the temperature effect is more obvious in quantum dots with weaker confinement.展开更多
This article describes model of human eye fluctuations such as refraction etc. and makes its physical interpretation. Because mistakes in refraction measurements correspond to fluctuations in eye＇s focus, it is possi...This article describes model of human eye fluctuations such as refraction etc. and makes its physical interpretation. Because mistakes in refraction measurements correspond to fluctuations in eye＇s focus, it is possible to calculate theoretical limits for the best accuracy in measurements of eye＇s refraction （0.25-0.3 D）. Optical model for astigmatic human eye predicts possibility only 70% compensation of visual acuity by cylindrical glasses. New data and methods for digital measuring of color and gray vision were tested, too. Also ,some new results and model for periphery color and grey vision were proposed and discussed.展开更多
An efficient and sensitive ion-pair HPLC-UV method using atenolol as internal standard （IS） was developed and validated for the determination of metformin in the plasma of diabetic rats. Plasma samples were deprotei...An efficient and sensitive ion-pair HPLC-UV method using atenolol as internal standard （IS） was developed and validated for the determination of metformin in the plasma of diabetic rats. Plasma samples were deproteinated with 10% （v/v） perchloric acid. Separation was achieved on a UltimateTM AQ-C18 column （250 mm×4.6 mm, 5 μm） with a mobile phase （pH 5.05） composed of acetonitrile-water （31：69, v/v, containing 0.002 M sodium dodecyl sulfate, 0.0125 M potassium dihydrogen phosphate, 0.015 M triethylamine） at a flow rate of 1.0 mL/min. The calibration curve was linear （r〉0.994） between 7.5 and 4000 ng/mL. The lower limit of quantification （LLOQ） was 7.5 ng/mL. The precision was validated and the relative standard deviation was in the range of 1.87% to 15.70%; the accuracy was between 93.98%-106.89%. The mean recoveries were 95.40% and 95.31% for metformin and IS, respectively. The relative error （RE） of stability at different storage conditions was within ±9.00%. This method was used to determine the concentration-time profile of metformin in diabetic rat plasma following an oral administration of metformin at the dose of 10 mg/kg. Our results indicated that ion-pair HPLC-UV method using UltimateTM AQ-C18 column was effective for the pharmacokinetic studies of high polarity compounds like metformin.展开更多
基金Supported in part by the Key Research Plan of Theoretical Physics and Cross Science of China under Grant No. 90503011National Science Foundation under Grant No. 10775012
文摘Using the Dyson-Schwinger equation and perturbation theory, we calculate the mixed quark-gluon condensates in the chiral limit and in the case of nonzero quark current mass for the light quark u/d and strange quark s. The results show that the mixed quark-gluon condensate will decrease when the quark mass increases. For the quark with zero mass, we obtain mo2 = g（qσuvGuvq）/（qq） 0.68 GeV2, which is in good agreement with the QCD sum rules estimate mo2=（0.8± 0.2） GeV2.
基金supported by National Natural Science Foundation of China under Grant Nos.10547101,10647108,and 10604002the National Fundamental Research Program of China under Grant No.2006CB921200
文摘When a boson interacts with another to form a composite system with SO（3） dynamic symmetry, it is shown that there exists the q-deformed 5osonic excitation satisfying the q-deformed Heisenberg commutation relation in the quasi-classical limit that the angular momentum j for SO（3） is large, but not infinite. In second quantization this quasi-excitation is associated with the boson realization of SO（3） Lie algebra. Physically, the phenomena of q-deformed excitation can happen in many models of quantum dynamics, such as super emission from a system of many identical two-level atoms, the spin wave in Heisenberg chain, the high spin precession and the coherent output of Bose-Einstein atoms in a trap. Especially, in these models, the deformation parameter q is well defined intrinsically by a conservative quantity, such as the total atomic number and the angular momentum.
基金Supported by Shanghai Leading Academic Discipline Project(B408)National Key Project for Basic Research of China under Grant Nos.2010CB923203,2006CB806006,and 2006CB921105+1 种基金National Natural Science Foundation of China under Grant Nos.10904038 and 10874044Shanghai Municipal Science and Technology Commission under Grant Nos.09JC1404700 and 08PJ1404800
文摘By using the dispersion theory instead of the Frohlich Hamiltonian, the polaron energy in a quantum aot with a parabolic confinement potential is investigated at finite temperatures. It is found that the self-trapping energy of the polaron decreases with the increasing temperature, and the temperature effect is more obvious in quantum dots with weaker confinement.
文摘This article describes model of human eye fluctuations such as refraction etc. and makes its physical interpretation. Because mistakes in refraction measurements correspond to fluctuations in eye＇s focus, it is possible to calculate theoretical limits for the best accuracy in measurements of eye＇s refraction （0.25-0.3 D）. Optical model for astigmatic human eye predicts possibility only 70% compensation of visual acuity by cylindrical glasses. New data and methods for digital measuring of color and gray vision were tested, too. Also ,some new results and model for periphery color and grey vision were proposed and discussed.
基金National Integrity Innovational Technology Platform of New Drug and Research and Development (Grant No.2009ZX09201-010)Innovation Team of Ministry of Education(Grant No. BMU20110263)
文摘An efficient and sensitive ion-pair HPLC-UV method using atenolol as internal standard （IS） was developed and validated for the determination of metformin in the plasma of diabetic rats. Plasma samples were deproteinated with 10% （v/v） perchloric acid. Separation was achieved on a UltimateTM AQ-C18 column （250 mm×4.6 mm, 5 μm） with a mobile phase （pH 5.05） composed of acetonitrile-water （31：69, v/v, containing 0.002 M sodium dodecyl sulfate, 0.0125 M potassium dihydrogen phosphate, 0.015 M triethylamine） at a flow rate of 1.0 mL/min. The calibration curve was linear （r〉0.994） between 7.5 and 4000 ng/mL. The lower limit of quantification （LLOQ） was 7.5 ng/mL. The precision was validated and the relative standard deviation was in the range of 1.87% to 15.70%; the accuracy was between 93.98%-106.89%. The mean recoveries were 95.40% and 95.31% for metformin and IS, respectively. The relative error （RE） of stability at different storage conditions was within ±9.00%. This method was used to determine the concentration-time profile of metformin in diabetic rat plasma following an oral administration of metformin at the dose of 10 mg/kg. Our results indicated that ion-pair HPLC-UV method using UltimateTM AQ-C18 column was effective for the pharmacokinetic studies of high polarity compounds like metformin.
