Fast ionic conductors are one kind of solid state material with ionic conductivity as high as that of melten salts or liquid electrolytes.Ionic conductivity is one of the important parameters for characterizing a fast...Fast ionic conductors are one kind of solid state material with ionic conductivity as high as that of melten salts or liquid electrolytes.Ionic conductivity is one of the important parameters for characterizing a fast ionic conductor.For a long time materialists and chemists have made great efforts in search of new fast ionic conductors with high ionic conductivity.In view of structure,they have synthesised silver and copper fast ionic conductors with so called open structures.But it is not so successful for searching more applicable alkaline fast ionic conductors.Since polymer has flexibility for making thin film,it concentrates attention on the polymer-alkaline salt complex.Fenton et al.have first reported poly(ethylene oxide) (PEO)-alkaline salt complex.Later on Armard et al.have investigated the electrical property of PEO-NaSCN.展开更多
We have investigated the electrical properties of carbon black (CB) loaded in ethylene butylacrylate copolymer composite (EBA) in the frequency range between 102 and 104 Hz and temperature range between 153 and 353 K....We have investigated the electrical properties of carbon black (CB) loaded in ethylene butylacrylate copolymer composite (EBA) in the frequency range between 102 and 104 Hz and temperature range between 153 and 353 K. The frequency dependence of electrical data that have been analyzed in two frameworks: the electrical modulus formalism with the Kohlrausch-Williams-Watts stretched exponential function (KWW) and the electrical conductivity by using the Jonscher’s power law in the frequency domain. The stretching exponent βKWW and n are found to be temperature independent for all CB fractions and to be decreased when the CB volume concentrations loaded in copolymer matrix increases. It is found that the activation energy obtained by the modulus method is in good agreement with that obtained by the DC conductivity in the power law which is independent on the CB contents that exist in the copolymer matrix, suggesting that these particles do not interact significantly with the chain segments of the macromolecules in the EBA copolymer.展开更多
The electrical and optical effects of particles on the nano aluminum film deposited by thermal evaporation was investigated. From the characterization results of scanning electron microscope(SEM), the accumulation i...The electrical and optical effects of particles on the nano aluminum film deposited by thermal evaporation was investigated. From the characterization results of scanning electron microscope(SEM), the accumulation in tens of nanometers had been observed. The current-voltage(I-V) curve of the sample indicates its nonlinear electrical characters expecting the corresponding nonlinear optical properties. By the theoretical calculation, nonlinear conduction of the carrier transportation may result from the barrier-well-barrier structure, where negative resistance and Coulomb blockade effect appears. The simulation results are approximately matched with the experimental results. By testing the fluorescence emission spectrum of the sample, peaks were found to be located at 420 and 440 nm. In addition, the full width at half maximum(FWHM) had been obviously broadened by means of adding 2, 5-diphenyloxazole(DPO). Therefore, discrete energy levels could be estimated inside those particles.展开更多
The thermally expandable microspheres(TEMs) were prepared via suspension polymerization with acrylonitrile(AN), methyl methacrylate(MMA) and methyl acrylate(MA) as monomers and n-hexane as the blowing agent. M...The thermally expandable microspheres(TEMs) were prepared via suspension polymerization with acrylonitrile(AN), methyl methacrylate(MMA) and methyl acrylate(MA) as monomers and n-hexane as the blowing agent. Meanwhile, a novel type of functional and conductive thermal expandable microsphere was obtained through strongly covering the surface of microsphere by conductive polymers with the mass loading of 1.5%. The optimal conditions to prepare high foaming ratio and equally distributed microcapsules were investigated with AN-MMA-MA in the proportion of 70%/20%/10%(m/m/m), and 25 wt% of n-hexane in oil phase. The further investigation results showed that the unexpanded TEMs were about 30 μm in diameter and the maximum expansion ratio was nearly 125 times of original volume. The polypyrrole(PPy) was smoothly coated on the surface of the TEMs and the expansion property of PPy-coated TEMs was almost the same as the uncoated TEMs. Moreover, the structure and expanding performance of TEMs and PPy-coated TEMs were characterized by scanning electron microscopy(SEM), laser particle size analyzer and dilatometer(DIL).展开更多
This paper proposes a new hybrid maximum power point tracking(MPPT)control strategy for grid-connected solar systems based on Incremental conductance—Particle Swarm Optimization and Model Predictive Controller(IncCon...This paper proposes a new hybrid maximum power point tracking(MPPT)control strategy for grid-connected solar systems based on Incremental conductance—Particle Swarm Optimization and Model Predictive Controller(IncCond-PSOMPC).The purpose of the suggested method is to create as much power as feasible from a PV system during environmental changes,then transfer it to the power grid.To accomplish this,a hybrid combination of incremental conductance(IncCond)and particle swarm optimization(PSO)is proposed to locate maximum power,followed by model predictive control(MPC)to track maximum power and control the boost converter to achieve high performance regardless of parameter variations.A two-level inverter,likewise,controlled by Model Predictive Control,is employed to inject the PV power generated.In this application,the MPC is based on minimizing the difference between the reference and prediction powers,which is computed to select the switching state of the inverter.The proposed system is simulated and evaluated in a variety of dynamic conditions using Matlab/Simulink.Results reveal that the proposed control mechanism is effective at tracking the maximum power point(MPP)with fewer power oscillations.展开更多
文摘Fast ionic conductors are one kind of solid state material with ionic conductivity as high as that of melten salts or liquid electrolytes.Ionic conductivity is one of the important parameters for characterizing a fast ionic conductor.For a long time materialists and chemists have made great efforts in search of new fast ionic conductors with high ionic conductivity.In view of structure,they have synthesised silver and copper fast ionic conductors with so called open structures.But it is not so successful for searching more applicable alkaline fast ionic conductors.Since polymer has flexibility for making thin film,it concentrates attention on the polymer-alkaline salt complex.Fenton et al.have first reported poly(ethylene oxide) (PEO)-alkaline salt complex.Later on Armard et al.have investigated the electrical property of PEO-NaSCN.
基金supported by an action integrated(N°Physique/04/08/09)granted by the Portugal-Moroccan committee.
文摘We have investigated the electrical properties of carbon black (CB) loaded in ethylene butylacrylate copolymer composite (EBA) in the frequency range between 102 and 104 Hz and temperature range between 153 and 353 K. The frequency dependence of electrical data that have been analyzed in two frameworks: the electrical modulus formalism with the Kohlrausch-Williams-Watts stretched exponential function (KWW) and the electrical conductivity by using the Jonscher’s power law in the frequency domain. The stretching exponent βKWW and n are found to be temperature independent for all CB fractions and to be decreased when the CB volume concentrations loaded in copolymer matrix increases. It is found that the activation energy obtained by the modulus method is in good agreement with that obtained by the DC conductivity in the power law which is independent on the CB contents that exist in the copolymer matrix, suggesting that these particles do not interact significantly with the chain segments of the macromolecules in the EBA copolymer.
基金Supported by the 973 Program(No.2014CB932103)the 863 Program(No.2013AA032501)the National Natural Science Foundation of China(NSFC No.21676015)
文摘The electrical and optical effects of particles on the nano aluminum film deposited by thermal evaporation was investigated. From the characterization results of scanning electron microscope(SEM), the accumulation in tens of nanometers had been observed. The current-voltage(I-V) curve of the sample indicates its nonlinear electrical characters expecting the corresponding nonlinear optical properties. By the theoretical calculation, nonlinear conduction of the carrier transportation may result from the barrier-well-barrier structure, where negative resistance and Coulomb blockade effect appears. The simulation results are approximately matched with the experimental results. By testing the fluorescence emission spectrum of the sample, peaks were found to be located at 420 and 440 nm. In addition, the full width at half maximum(FWHM) had been obviously broadened by means of adding 2, 5-diphenyloxazole(DPO). Therefore, discrete energy levels could be estimated inside those particles.
基金the National Natural ScienceFoundation of China(Nos.21206171,21376010)the Project of Natural Science Foundation of Beijing(No.2152012)+1 种基金the Young Elite Teacher Project(No.27170115004/027)the Project of 2011 Collaborative Innovation for Green Printing and Publishing Technology and the Project of Beijing Municipal Commission of Educatio (No.km201410005007)for the financial supports
文摘The thermally expandable microspheres(TEMs) were prepared via suspension polymerization with acrylonitrile(AN), methyl methacrylate(MMA) and methyl acrylate(MA) as monomers and n-hexane as the blowing agent. Meanwhile, a novel type of functional and conductive thermal expandable microsphere was obtained through strongly covering the surface of microsphere by conductive polymers with the mass loading of 1.5%. The optimal conditions to prepare high foaming ratio and equally distributed microcapsules were investigated with AN-MMA-MA in the proportion of 70%/20%/10%(m/m/m), and 25 wt% of n-hexane in oil phase. The further investigation results showed that the unexpanded TEMs were about 30 μm in diameter and the maximum expansion ratio was nearly 125 times of original volume. The polypyrrole(PPy) was smoothly coated on the surface of the TEMs and the expansion property of PPy-coated TEMs was almost the same as the uncoated TEMs. Moreover, the structure and expanding performance of TEMs and PPy-coated TEMs were characterized by scanning electron microscopy(SEM), laser particle size analyzer and dilatometer(DIL).
文摘This paper proposes a new hybrid maximum power point tracking(MPPT)control strategy for grid-connected solar systems based on Incremental conductance—Particle Swarm Optimization and Model Predictive Controller(IncCond-PSOMPC).The purpose of the suggested method is to create as much power as feasible from a PV system during environmental changes,then transfer it to the power grid.To accomplish this,a hybrid combination of incremental conductance(IncCond)and particle swarm optimization(PSO)is proposed to locate maximum power,followed by model predictive control(MPC)to track maximum power and control the boost converter to achieve high performance regardless of parameter variations.A two-level inverter,likewise,controlled by Model Predictive Control,is employed to inject the PV power generated.In this application,the MPC is based on minimizing the difference between the reference and prediction powers,which is computed to select the switching state of the inverter.The proposed system is simulated and evaluated in a variety of dynamic conditions using Matlab/Simulink.Results reveal that the proposed control mechanism is effective at tracking the maximum power point(MPP)with fewer power oscillations.