The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 an...The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 and 600°C.The values of the cross point between the curves of the real and imaginary parts of the optical conductivity ɑ_1 and ɑ_1 with energy axis of films exhibit values that correspond to optical gaps and are about 3.25-3.3 eV. The maxima of peaks in plots dR/dλ and dT/dλ versus wavelength of films exhibit optical gaps at about 3.12-3.25 eV.The values of the fundamental indirect band gap obtained from the Tauc model are at about 3.14-3.2 eV. It can be seen that films annealed at 600°C have the minimum indirect optical band gap at about 3.15 eV. The films annealed at 600°C have Urbach＇s energy minimum of 1.38 eV and hence have minimum disorder. The dispersion energy d of films annealed at 500°C has the minimum value of 43 eV.展开更多
Co-precipitation was used to prepare cerium oxide nano-particles. The effects of aging temperature and concentration of cobalt ion on the optical property, morphology, and particle size were investigated. The cerium o...Co-precipitation was used to prepare cerium oxide nano-particles. The effects of aging temperature and concentration of cobalt ion on the optical property, morphology, and particle size were investigated. The cerium oxide was prepared by adding ammonia solution into a mixed solution of cerium nitrate with cobalt nitrate solutions to obtain a large amount of precipitates and then aged further. Subsequently, the precipitates were kept in an oven for calcination keeping the temperature at 400?C for lasting 24 h. The average size of cerium oxide particles was obtained from the (111) peak in the X-ray diffraction pattern using the Scherrer equation. The crystal sizes obtained were found to be in the range of 11.82 - 13.47 nm. The results showed that the particle size decreased with an increase in the Co ion concentration and decreased with an increase in temperature. The SEM pictures show that the morphology for cerium oxide is granular and/or columnar. It can be seen from UV/Vis absorption spectrum that the maximum absorption peaks were in the range of 334 - 390 nm, depending on the operating conditions. The corresponding energy gaps were observed in the range of 3.18 - 3.71 eV. Subsequently, the Brus equation for the energy gap was discussed. Finally, particle size was correlated with the aging temperature and Co ion concentration.展开更多
In this paper, the elastic wave propagation in a two-dimensional piezoelectric phononic crystal is studied by considering the mechanic-electric coupling. The generalized eigenvalue equation is obtained by the relation...In this paper, the elastic wave propagation in a two-dimensional piezoelectric phononic crystal is studied by considering the mechanic-electric coupling. The generalized eigenvalue equation is obtained by the relation of the mechanic and electric fields as well as the Bloch-Floquet theorem. The band structures of both the in-plane and anti-plane modes are calculated for a rectangular lattice by the planewave expansion method. The effects of the lattice constant ratio and the piezoelectricity with different filling fractions are analyzed. The results show that the largest gap width is not always obtained for a square lattice. In some situations, a rectangular lattice may generate larger gaps. The band gap characteristics are influenced obviously by the piezoelectricity with the larger lattice constant ratios and the filling fractions.展开更多
Based on the analysis methods of non-parametric Malmquist index and spatial econometrics as well as the provincial panel data in 2007-2010, this paper estimates the efficiency of fiscal expenditure from local governme...Based on the analysis methods of non-parametric Malmquist index and spatial econometrics as well as the provincial panel data in 2007-2010, this paper estimates the efficiency of fiscal expenditure from local governments in china in terms of reducing the income gap between urban and rural residents for the first time and evaluates the spatial correlation and heterogeneity of this efficiency. The results have shown that the fiscal expenditure of most provinces is of low efficiency in reducing the income gap between urban and rural residents, and the expenditure efficiency of local governments is not relevant to their levels of economic development. Besides, the efficiency on reducing the urban-rural income gap between different regions of China has a tendency of convergence. But this is mainly reflected inside the regional economic belt. There is significant difference between the efficiency of each economic belt. The central region has the highest efficiency in a rising trend, the western region has the lowest efficiency in a downward trend, while the eastern region is relatively stable.展开更多
In this study, the propagation of electromagnetic waves in one-dimensional plasma photonic crystals （PPCs）, namely, superlattice structures consisting alternately of a homogeneous unmagnetized plasma and dielectric ...In this study, the propagation of electromagnetic waves in one-dimensional plasma photonic crystals （PPCs）, namely, superlattice structures consisting alternately of a homogeneous unmagnetized plasma and dielectric material, is simulated numerically using the finite-difference time-domain （FDTD） algorithm. A perfectly matched layer （PML） absorbing technique is used in this simulation. The reflection and transmission coefficients of electromagnetic （EM） waves through PPCs are calculated. The characteristics of the photonic band gap （PBG） are discussed in terms of plasma density, dielectric constant ratios, number of periods, and introduced layer defect. These may provide some useful information for designing plasma photonic crystal devices.展开更多
We investigate the roles of different qubit-environment decoherence models on the entanglement trapping of two qubits. By considering three environmental models （the single photonic band gap model, the common photoni...We investigate the roles of different qubit-environment decoherence models on the entanglement trapping of two qubits. By considering three environmental models （the single photonic band gap model, the common photonic band gap model, and the two independent photonic band gaps model）, we note that the final values of entanglement trapping are determined by these different models. We also give the conditions of obtaining the larger entanglement trapping by comparing two-qubit entanglement dynamics in different decoherence models. Moreover, the comparison of entanglement trapping between two Bell-like states in the same decoherence model are also carried out.展开更多
Gap non-union of the tibia is frequently associated with deformity, infection and shortening. Ilizarov’s method of bone transport was used in the management of twenty-five cases of gap non-union of the tibia. The mea...Gap non-union of the tibia is frequently associated with deformity, infection and shortening. Ilizarov’s method of bone transport was used in the management of twenty-five cases of gap non-union of the tibia. The mean bone gap was 6.53 cm (range 4 to 12 cm). Union was achieved in all cases within a mean period of 11.12 months. The mean time taken for union, per centimeter of bone gap was found to be 1.7 months/cm. Pin tract infection was the commonest complication, seen in 9 cases (36%). The other complications encountered were neuropraxia (n = 3) deviation of the transported bone segment (n = 7), buckling of skin at the advancing side of bone (n = 4), traumatic corticotomy (n = 3), incomplete corticotomy (n = 1), equinus deformity (n = 4), knee stiffness (n = 4) and curling of toes (n = 4). The bone healing results were excellent in 92% of cases and good in 8% of cases. The functional results were excellent in 84% of cases, good in 12% and fair in 4% of cases. Thus bone transport by Ilizarov’s method manages the bone loss and the associated conditions with good bone healing and functional results.展开更多
With the full-vector plane-wave method （FVPWM） and the full-vector beam propagation method （FVBPM）, the dependences of the band-gap and mode characteristics on material index and cladding structure parameter in an...With the full-vector plane-wave method （FVPWM） and the full-vector beam propagation method （FVBPM）, the dependences of the band-gap and mode characteristics on material index and cladding structure parameter in anti- resonance guiding photonic crystal fibres （ARGPCFs） are sufficiently analysed. An ARGPCF operating in the near- infrared wavelength is shown. The influences of the high index cylinders, glass interstitial apexes and silica structure on the characteristics of band-gaps and modes are deeply investigated. The equivalent planar waveguide theory is used for analysing such an ARGPCF filled by the isotropic materials, and the resonance and the anti-resonance characteristics r：~n h~ w~｜] r^r~dlrtpd展开更多
A self-assembly method, named the angle controlled inclined deposition method, is developed for fabricating well- ordered silica and polystyrene colloidal crystals. A high-quality colloidal crystal with a flat and uni...A self-assembly method, named the angle controlled inclined deposition method, is developed for fabricating well- ordered silica and polystyrene colloidal crystals. A high-quality colloidal crystal with a flat and uniform surface over a large area can be produced rapidly using a minute quantity of suspension and without any additional equipment. By controlling the inclined angle, we can fabricate colloidal crystals with diverse numbers of layers. A colloidal crystal double-heterostructure （composed of three different colloidal photonic crystals） can be rapidly fabricated with this method. Both experimental and simulation results show that the photonic band gap of the double-heterostructure is not a simple superposition of that of the compositional colloidal crystals along the stacking direction.展开更多
The complete band gaps （CBGs） of shallow water waves propagating over bottoms with periodically drilled holes are investigated numerically by the plane wave expansion method. Four different patterns are considered, ...The complete band gaps （CBGs） of shallow water waves propagating over bottoms with periodically drilled holes are investigated numerically by the plane wave expansion method. Four different patterns are considered, containing triangular, square, hexagonal and circular cross-sectioned holes arranged into triangular lattices. Results show that the width of CBGs can be changed by adjusting the orientation of noncircular holes and the effect of hole shape on the width of the maximal CBGs is discussed.展开更多
The factors affecting one dimensional （1D） and two dimensional （2D） photonic crystals （PhCs） are systemically analyzed in this paper by numerical simulation. Transfer matrix method （TMM） is employed for 1D PCs...The factors affecting one dimensional （1D） and two dimensional （2D） photonic crystals （PhCs） are systemically analyzed in this paper by numerical simulation. Transfer matrix method （TMM） is employed for 1D PCs, both finite difference time domain method （FDTD） and plane wave expansion method （PWE） are employed for 2D PCs. The result shows that the photonic bandgaps （PBG） are directly affected by crystal type, crystal lattice constant, modulation of refractive index and periodicity, and it is should be useful for design of different type photonic crystals with the required PBG and functional devices. Finally, as an example, a near-IR 1D PCs narrow filter was designed.展开更多
Based on the analysis of the grain supply and demand gap’s current situation in China, this paper establishes an indicator system for the influence factors of grain supply and demand gap. Then this paper calculates t...Based on the analysis of the grain supply and demand gap’s current situation in China, this paper establishes an indicator system for the influence factors of grain supply and demand gap. Then this paper calculates the correlation degree between the main grain varieties’ supply and demand gap and its influence factors. The results show that sown area and unit yield have the greatest impact on wheat supply and demand gap;per capita disposable income and unit yield have the greatest impact on corn supply and demand gap;per capita disposable income and agricultural mechanization level have the greatest impact on the supply and demand gap of soybean and rice. From the analysis results, we can obtain the difference between the factors affecting the grain supply and demand gap, and provide a certain theoretical basis and new ideas for the balance of grain supply and demand in China.展开更多
文摘The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 and 600°C.The values of the cross point between the curves of the real and imaginary parts of the optical conductivity ɑ_1 and ɑ_1 with energy axis of films exhibit values that correspond to optical gaps and are about 3.25-3.3 eV. The maxima of peaks in plots dR/dλ and dT/dλ versus wavelength of films exhibit optical gaps at about 3.12-3.25 eV.The values of the fundamental indirect band gap obtained from the Tauc model are at about 3.14-3.2 eV. It can be seen that films annealed at 600°C have the minimum indirect optical band gap at about 3.15 eV. The films annealed at 600°C have Urbach＇s energy minimum of 1.38 eV and hence have minimum disorder. The dispersion energy d of films annealed at 500°C has the minimum value of 43 eV.
文摘Co-precipitation was used to prepare cerium oxide nano-particles. The effects of aging temperature and concentration of cobalt ion on the optical property, morphology, and particle size were investigated. The cerium oxide was prepared by adding ammonia solution into a mixed solution of cerium nitrate with cobalt nitrate solutions to obtain a large amount of precipitates and then aged further. Subsequently, the precipitates were kept in an oven for calcination keeping the temperature at 400?C for lasting 24 h. The average size of cerium oxide particles was obtained from the (111) peak in the X-ray diffraction pattern using the Scherrer equation. The crystal sizes obtained were found to be in the range of 11.82 - 13.47 nm. The results showed that the particle size decreased with an increase in the Co ion concentration and decreased with an increase in temperature. The SEM pictures show that the morphology for cerium oxide is granular and/or columnar. It can be seen from UV/Vis absorption spectrum that the maximum absorption peaks were in the range of 334 - 390 nm, depending on the operating conditions. The corresponding energy gaps were observed in the range of 3.18 - 3.71 eV. Subsequently, the Brus equation for the energy gap was discussed. Finally, particle size was correlated with the aging temperature and Co ion concentration.
基金the National Natural Science Foundation of China (10672017 and 10632020)
文摘In this paper, the elastic wave propagation in a two-dimensional piezoelectric phononic crystal is studied by considering the mechanic-electric coupling. The generalized eigenvalue equation is obtained by the relation of the mechanic and electric fields as well as the Bloch-Floquet theorem. The band structures of both the in-plane and anti-plane modes are calculated for a rectangular lattice by the planewave expansion method. The effects of the lattice constant ratio and the piezoelectricity with different filling fractions are analyzed. The results show that the largest gap width is not always obtained for a square lattice. In some situations, a rectangular lattice may generate larger gaps. The band gap characteristics are influenced obviously by the piezoelectricity with the larger lattice constant ratios and the filling fractions.
基金Supported by National Science Fund for Distinguished Young Scholars(GrantNo.:70825003)Key Project of National Social Science Foundation(GrantNo.:07AJL002,12AGL008 and 12ASH004)+3 种基金Young Scholar Project of National Social Science Foundation(Grant No.:12CGL063 and 12CJY062)Key Project of Ministry of Education(Grant No.:DFA100209)Social Science Planning Fund of Ministry of Education (Grant No.:07JA790104)Foundation Project for Central Universities-Xiamen University(Grant No. :2009ZK1007)
文摘Based on the analysis methods of non-parametric Malmquist index and spatial econometrics as well as the provincial panel data in 2007-2010, this paper estimates the efficiency of fiscal expenditure from local governments in china in terms of reducing the income gap between urban and rural residents for the first time and evaluates the spatial correlation and heterogeneity of this efficiency. The results have shown that the fiscal expenditure of most provinces is of low efficiency in reducing the income gap between urban and rural residents, and the expenditure efficiency of local governments is not relevant to their levels of economic development. Besides, the efficiency on reducing the urban-rural income gap between different regions of China has a tendency of convergence. But this is mainly reflected inside the regional economic belt. There is significant difference between the efficiency of each economic belt. The central region has the highest efficiency in a rising trend, the western region has the lowest efficiency in a downward trend, while the eastern region is relatively stable.
基金supported by the Program for New Century Excellent Talents in University(No.NCET-05-0575)the Education Science Foundation of Jiangxi Province(No.Z-03510)
文摘In this study, the propagation of electromagnetic waves in one-dimensional plasma photonic crystals （PPCs）, namely, superlattice structures consisting alternately of a homogeneous unmagnetized plasma and dielectric material, is simulated numerically using the finite-difference time-domain （FDTD） algorithm. A perfectly matched layer （PML） absorbing technique is used in this simulation. The reflection and transmission coefficients of electromagnetic （EM） waves through PPCs are calculated. The characteristics of the photonic band gap （PBG） are discussed in terms of plasma density, dielectric constant ratios, number of periods, and introduced layer defect. These may provide some useful information for designing plasma photonic crystal devices.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61178012 and 11247240)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20123705120002)+3 种基金the Open Project of State Key Laboratory of Crystal Material in Shandong University, China (Grant No. KF1103)the Natural Science Foundation of Shandong Province, China (Grant No. ZR2012FQ024)the Youth Funds from Qufu Normal University, China (Grant No. XJ201219)the Scientific Research Foundation for Doctors of Qufu Normal University, China (Grant No. BSQD20110132)
文摘We investigate the roles of different qubit-environment decoherence models on the entanglement trapping of two qubits. By considering three environmental models （the single photonic band gap model, the common photonic band gap model, and the two independent photonic band gaps model）, we note that the final values of entanglement trapping are determined by these different models. We also give the conditions of obtaining the larger entanglement trapping by comparing two-qubit entanglement dynamics in different decoherence models. Moreover, the comparison of entanglement trapping between two Bell-like states in the same decoherence model are also carried out.
文摘Gap non-union of the tibia is frequently associated with deformity, infection and shortening. Ilizarov’s method of bone transport was used in the management of twenty-five cases of gap non-union of the tibia. The mean bone gap was 6.53 cm (range 4 to 12 cm). Union was achieved in all cases within a mean period of 11.12 months. The mean time taken for union, per centimeter of bone gap was found to be 1.7 months/cm. Pin tract infection was the commonest complication, seen in 9 cases (36%). The other complications encountered were neuropraxia (n = 3) deviation of the transported bone segment (n = 7), buckling of skin at the advancing side of bone (n = 4), traumatic corticotomy (n = 3), incomplete corticotomy (n = 1), equinus deformity (n = 4), knee stiffness (n = 4) and curling of toes (n = 4). The bone healing results were excellent in 92% of cases and good in 8% of cases. The functional results were excellent in 84% of cases, good in 12% and fair in 4% of cases. Thus bone transport by Ilizarov’s method manages the bone loss and the associated conditions with good bone healing and functional results.
基金partly supported by the National Key Basic Research Special Foundation of China (Grant Nos. 2010CB327605 and 2010CB328300)the National High-Technology Research and Development Program of China (Grant No. 2009AA01Z220)+3 种基金the Key Grant of the Chinese Ministry of Education (Grant No. 109015)the Discipline Co-construction Project of Beijing Municipal Commission of Education,China (Grant No. YB20081001301)the Open Fund of Key Laboratory of Information Photonics and Optical Communications (Beijing University of Posts and Telecommunications),Chinese Ministry of Educationthe Specialized Research Fund for the Doctoral Program of Beijing University of Posts and Telecommunications (Grant No. CX201023)
文摘With the full-vector plane-wave method （FVPWM） and the full-vector beam propagation method （FVBPM）, the dependences of the band-gap and mode characteristics on material index and cladding structure parameter in anti- resonance guiding photonic crystal fibres （ARGPCFs） are sufficiently analysed. An ARGPCF operating in the near- infrared wavelength is shown. The influences of the high index cylinders, glass interstitial apexes and silica structure on the characteristics of band-gaps and modes are deeply investigated. The equivalent planar waveguide theory is used for analysing such an ARGPCF filled by the isotropic materials, and the resonance and the anti-resonance characteristics r：~n h~ w~｜] r^r~dlrtpd
基金Project supported by the Guangdong Province Natural Science Foundation, China (Grant No. 8151063101000030)the National Natural Science Foundation of China (Grant No. 10504008)the Key Project of Chinese Ministry of Education (Grant No. 209091)
文摘A self-assembly method, named the angle controlled inclined deposition method, is developed for fabricating well- ordered silica and polystyrene colloidal crystals. A high-quality colloidal crystal with a flat and uniform surface over a large area can be produced rapidly using a minute quantity of suspension and without any additional equipment. By controlling the inclined angle, we can fabricate colloidal crystals with diverse numbers of layers. A colloidal crystal double-heterostructure （composed of three different colloidal photonic crystals） can be rapidly fabricated with this method. Both experimental and simulation results show that the photonic band gap of the double-heterostructure is not a simple superposition of that of the compositional colloidal crystals along the stacking direction.
基金supported by the National Natural Science Foundation of China (Grant No. 10674032)
文摘The complete band gaps （CBGs） of shallow water waves propagating over bottoms with periodically drilled holes are investigated numerically by the plane wave expansion method. Four different patterns are considered, containing triangular, square, hexagonal and circular cross-sectioned holes arranged into triangular lattices. Results show that the width of CBGs can be changed by adjusting the orientation of noncircular holes and the effect of hole shape on the width of the maximal CBGs is discussed.
基金Sponsored by the Ministerial Level Advanced Research Foundation (1006513002060)
文摘The factors affecting one dimensional （1D） and two dimensional （2D） photonic crystals （PhCs） are systemically analyzed in this paper by numerical simulation. Transfer matrix method （TMM） is employed for 1D PCs, both finite difference time domain method （FDTD） and plane wave expansion method （PWE） are employed for 2D PCs. The result shows that the photonic bandgaps （PBG） are directly affected by crystal type, crystal lattice constant, modulation of refractive index and periodicity, and it is should be useful for design of different type photonic crystals with the required PBG and functional devices. Finally, as an example, a near-IR 1D PCs narrow filter was designed.
文摘Based on the analysis of the grain supply and demand gap’s current situation in China, this paper establishes an indicator system for the influence factors of grain supply and demand gap. Then this paper calculates the correlation degree between the main grain varieties’ supply and demand gap and its influence factors. The results show that sown area and unit yield have the greatest impact on wheat supply and demand gap;per capita disposable income and unit yield have the greatest impact on corn supply and demand gap;per capita disposable income and agricultural mechanization level have the greatest impact on the supply and demand gap of soybean and rice. From the analysis results, we can obtain the difference between the factors affecting the grain supply and demand gap, and provide a certain theoretical basis and new ideas for the balance of grain supply and demand in China.
