On the condition of electric-LO phonon strong coupling in unsymmetrical parabolic confinement potential quantum dot （QD）, we obtain the eigenenergies of the ground state and the first-excited state, the eigenfunctio...On the condition of electric-LO phonon strong coupling in unsymmetrical parabolic confinement potential quantum dot （QD）, we obtain the eigenenergies of the ground state and the first-excited state, the eigenfunctions of the ground state, and the first-excited state by using variational method of Pekar type. This system in QD may be employed as a two-level quantum system-qubit. When the electron is in the superposition state of the ground state and the first-excited state, we obtain the time evolution of the electron density. The relations both the probability density of electron and the period of oscillation with the electron-LO-phonon coupling strength, the confinement strengths in the xy-plane and the z-direction are discussed.展开更多
Synthesis of composite oxides in the series Nd4-xCs2（1＋x）Fe5-xZnxO14＋δ（0≤x≤1.0） （B1-B5： x= 0.0, 0.25, 0.5, 0.75, 1.0） is performed by sol-gel method via nitrate-acetate precursor route. Analysis of the pow...Synthesis of composite oxides in the series Nd4-xCs2（1＋x）Fe5-xZnxO14＋δ（0≤x≤1.0） （B1-B5： x= 0.0, 0.25, 0.5, 0.75, 1.0） is performed by sol-gel method via nitrate-acetate precursor route. Analysis of the powder x-ray diffraction （XRD） patterns show tetragonal unit cell with lattice parameters a = 8.6545, 8.2520, 7.7645, 9.8952, 8.2863 A; b = 8.9800, 11.5788, 15.6305, 8.4766, 11.6465 A in B1-B5, respectively. The average crystallite sizes in the samples are found to be in the range 69.56-119.48 A. Energy dispersive analysis of x-rays （EDAX） result shows the presence of Fe, Nd, Cs and O, and Fe, Nd, Zn, Cs and O in B 1 （x=0） and B2（x=0.25）-B5（x= 1.0）, respectively. The IR results at 300 K show the presence of octahedral [NdO6/2]^3- （asymmetric stretch： 410-416 cml） and [FeO6/2]^3-（symmetric stretch： 562-572 cm^-1） units in the samples. Observed magnetic moments versus magnetic field plots in the range -10 kG to ＋10 kG exhibit hysteresis loops with average magnetic susceptibility values in the range 3.46 × 10^-5 -7.05 × 10^-5 emu/gG in B1-B5 shows fairly strong ferromagnetic nature of the samples. The observed EPR lineshapes at 300 and 77 K with giso=2.01-2.03 and giso=2.01-2.03, respectively is ascribed to the octahedral [FeO6/2]^3- coordination of Fe^3＋ （3d^5） ion. The optical absorption spectra show the transition of ^4I9/2→^4F7/2→^ 4S3/2 （750 nm） of optically active Nd^3＋ ions in samples.展开更多
Theranostics, combining therapy and diagnosis, is an appealing approach for chemotherapy. In the present study, we selected paclitaxel （PTX） as a therapeutic agent, super-paramagnetic iron oxide nanoparticles （SPIO...Theranostics, combining therapy and diagnosis, is an appealing approach for chemotherapy. In the present study, we selected paclitaxel （PTX） as a therapeutic agent, super-paramagnetic iron oxide nanoparticles （SPIO） as a diagnostic agent and sterically stabilized liposomes as a carrier to prepare theranostic liposomes. The SPIO were prepared and characterized. Moreover, the sterically stabilized liposomes containing PTX and SPIO （PTX/SPIO-SSL） were prepared. The characteristics of PTX/SPIO-SSL were investigated. The results indicated that prepared SPIO exhibited super-paramagnetic and could be used for MRI. The average particle size of PTX/SPIO-SSL was about 170 rim, with a polydispersity index （PDI） less than 0.3. The zeta potential of PTX/SPIO-SSL was negative. The PTX entrapment efficiency of PTX/SPIO-SSL was more than 98%. The TEM results indicated the spherical structure and dense SPIO content in PTX/SPIO-SSL. The in vitro release of PTX from PTX/SPIO-SSL and PTX-SSL was almost identical at both pH 6.8 and 7.4. In conclusion, the PTX/SPIO-SSL were prepared and characterized in vitro. The anti-tumor and diagnostic activity of PTX/SPIO-SSL should be investigated deeply in future study.展开更多
An equiatomic CoCrFeNiMn high entropy alloy （HEA） was produced by powder metallurgy method. Cold rolling followed by subsequent annealing was conducted to further optimize the microstructure and mechanical propertie...An equiatomic CoCrFeNiMn high entropy alloy （HEA） was produced by powder metallurgy method. Cold rolling followed by subsequent annealing was conducted to further optimize the microstructure and mechanical properties. The results show that the SPSed CoCrFeNiMn HEA has an equiaxed single fcc phase microstructrue. Cold rolling results in extensive dislocation pile-up and twinning within the grains. The 80% cold-rolled alloy shows very high yield strength of 1292 MPa, but a limited elongation of 3%. Subsequent annealing produces recrystallization and precipitation of fine a particles with particle size of 30-100 nm. The annealed alloy has a yield strength of 540 MPa, which is about two to three times of the cast CoCrFeNiMn HEA, while still maintains a high tensile ductility of 41%. The improvement of the tensile properties is caused by the grain boundary strengthening, solid solution strengthening, and precipitation strengthening.展开更多
文摘On the condition of electric-LO phonon strong coupling in unsymmetrical parabolic confinement potential quantum dot （QD）, we obtain the eigenenergies of the ground state and the first-excited state, the eigenfunctions of the ground state, and the first-excited state by using variational method of Pekar type. This system in QD may be employed as a two-level quantum system-qubit. When the electron is in the superposition state of the ground state and the first-excited state, we obtain the time evolution of the electron density. The relations both the probability density of electron and the period of oscillation with the electron-LO-phonon coupling strength, the confinement strengths in the xy-plane and the z-direction are discussed.
文摘Synthesis of composite oxides in the series Nd4-xCs2（1＋x）Fe5-xZnxO14＋δ（0≤x≤1.0） （B1-B5： x= 0.0, 0.25, 0.5, 0.75, 1.0） is performed by sol-gel method via nitrate-acetate precursor route. Analysis of the powder x-ray diffraction （XRD） patterns show tetragonal unit cell with lattice parameters a = 8.6545, 8.2520, 7.7645, 9.8952, 8.2863 A; b = 8.9800, 11.5788, 15.6305, 8.4766, 11.6465 A in B1-B5, respectively. The average crystallite sizes in the samples are found to be in the range 69.56-119.48 A. Energy dispersive analysis of x-rays （EDAX） result shows the presence of Fe, Nd, Cs and O, and Fe, Nd, Zn, Cs and O in B 1 （x=0） and B2（x=0.25）-B5（x= 1.0）, respectively. The IR results at 300 K show the presence of octahedral [NdO6/2]^3- （asymmetric stretch： 410-416 cml） and [FeO6/2]^3-（symmetric stretch： 562-572 cm^-1） units in the samples. Observed magnetic moments versus magnetic field plots in the range -10 kG to ＋10 kG exhibit hysteresis loops with average magnetic susceptibility values in the range 3.46 × 10^-5 -7.05 × 10^-5 emu/gG in B1-B5 shows fairly strong ferromagnetic nature of the samples. The observed EPR lineshapes at 300 and 77 K with giso=2.01-2.03 and giso=2.01-2.03, respectively is ascribed to the octahedral [FeO6/2]^3- coordination of Fe^3＋ （3d^5） ion. The optical absorption spectra show the transition of ^4I9/2→^4F7/2→^ 4S3/2 （750 nm） of optically active Nd^3＋ ions in samples.
基金Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20120001110012)
文摘Theranostics, combining therapy and diagnosis, is an appealing approach for chemotherapy. In the present study, we selected paclitaxel （PTX） as a therapeutic agent, super-paramagnetic iron oxide nanoparticles （SPIO） as a diagnostic agent and sterically stabilized liposomes as a carrier to prepare theranostic liposomes. The SPIO were prepared and characterized. Moreover, the sterically stabilized liposomes containing PTX and SPIO （PTX/SPIO-SSL） were prepared. The characteristics of PTX/SPIO-SSL were investigated. The results indicated that prepared SPIO exhibited super-paramagnetic and could be used for MRI. The average particle size of PTX/SPIO-SSL was about 170 rim, with a polydispersity index （PDI） less than 0.3. The zeta potential of PTX/SPIO-SSL was negative. The PTX entrapment efficiency of PTX/SPIO-SSL was more than 98%. The TEM results indicated the spherical structure and dense SPIO content in PTX/SPIO-SSL. The in vitro release of PTX from PTX/SPIO-SSL and PTX-SSL was almost identical at both pH 6.8 and 7.4. In conclusion, the PTX/SPIO-SSL were prepared and characterized in vitro. The anti-tumor and diagnostic activity of PTX/SPIO-SSL should be investigated deeply in future study.
基金supported by the National Key Research and Development Plan of China(Grant No.2016YFB0700302)the National Key Fundamental Research and Development Project of China(Grant No.2014CB644002)+3 种基金the National Natural Science Foundation of China(Grant No.51671217)the Science and Technology Planning Project of Hunan Province of China(Grant No.2015SK1002-1)the Innovation Driven Plan of Central South University(Grant No.2015CX004)the State Key Lab of Powder Metallurgy
文摘An equiatomic CoCrFeNiMn high entropy alloy （HEA） was produced by powder metallurgy method. Cold rolling followed by subsequent annealing was conducted to further optimize the microstructure and mechanical properties. The results show that the SPSed CoCrFeNiMn HEA has an equiaxed single fcc phase microstructrue. Cold rolling results in extensive dislocation pile-up and twinning within the grains. The 80% cold-rolled alloy shows very high yield strength of 1292 MPa, but a limited elongation of 3%. Subsequent annealing produces recrystallization and precipitation of fine a particles with particle size of 30-100 nm. The annealed alloy has a yield strength of 540 MPa, which is about two to three times of the cast CoCrFeNiMn HEA, while still maintains a high tensile ductility of 41%. The improvement of the tensile properties is caused by the grain boundary strengthening, solid solution strengthening, and precipitation strengthening.
