The role of bathophenanthroline (Bphen) as a buffer layer inserted between fullerene (C60) and Ag cathode in organic photovoltaic (OPV) cell was discussed. By introducing Bphen as a buffer layer with thicknes fr...The role of bathophenanthroline (Bphen) as a buffer layer inserted between fullerene (C60) and Ag cathode in organic photovoltaic (OPV) cell was discussed. By introducing Bphen as a buffer layer with thicknes from 0 to 2.5 nm, the power conversion efficiency of the OPV cell based on copper phthalocyanine (CuPc) and C60 was increased from 0.87% to 2.25% under AM 1.5 solar illumination at an intensity of 100 mW/cm^2, which was higher than that of bathocuproine used as a buffer layer. The photocurrent-voltage characteristics showed that Bphen effectively improves electron transport through C60 layer into Ag electrode and leads to balance charge carrier transport capability. The influence of Bphen thickness on OPV cells was also investigated. Furthermore, the absorption spectrum shows that an additional Bphen layer enhances the light harvest capability of CuPc/C60.展开更多
The model of ion transportation through graphene nanochannels is established by the molecular dynamics simulation method. Statistics of the electric potential and charge distribution are made, respectively, on both si...The model of ion transportation through graphene nanochannels is established by the molecular dynamics simulation method. Statistics of the electric potential and charge distribution are made, respectively, on both sides of graphene nanopore with various diameters. Then, their changing relationship with respect to the nanopore diameter is determined. When applying a uniform electric field, polar water molecules are rearranged so that the corresponding relationship between the polarized degree of these molecules and the nanopore diameter can be created. Based on the theoretical model of ion transportation through nanochannels,the changing relationship between the concentration of anions/cations in nanochannels and bulk solution concentration is quantitatively analyzed. The results show that the increase of potential drop and charge accumulation, as well as a more obvious water polarization, will occur with the decrease of nanopore diameter. In addition, hydrogen ion concentration has a large proportion in nanochannels with a sodium chloride(NaCl) solution at a relative low concentration. As the NaCl concentration increases, the concentration appreciation of sodium ions tends to be far greater than the concentration drop of chloride ions. Therefore, sodium ion concentration makes more contribution to ionic conductance.展开更多
Transport of nanoparticles and coagulation is simulated with the combination of CFD in a circular bend. The Taylor-expansion moment method(TEMOM)is employed to study dynamics of nanoparticles with Brownian motion,base...Transport of nanoparticles and coagulation is simulated with the combination of CFD in a circular bend. The Taylor-expansion moment method(TEMOM)is employed to study dynamics of nanoparticles with Brownian motion,based on the flow field from numerical simulation.A fully developed flow pattern in the present simulation is compared with previous numerical results for validating the model and computational code.It is found that for the simulated particulate flow system,the particle mass concentration,number concentration,particle polydispersity, mean particle diameter and geometric standard deviation over cross-section increase with time.The distribution of particle mass concentration at different time is independent of the initial particle size.More particles are concen-trated at outer edge of the bend.Coagulation plays more important role at initial stage than that in the subsequent period.The increase of Reynolds number and initial particle size leads to the increase of particle number concentration.The particle polydispersity,mean particle diameter and geometric standard deviation increase with decreasing Reynolds number and initial particle size.展开更多
Polyaniline (PANI)/silver composite was one-step synthesized under γ-ray irradiation. The structure of the composite was characterized by Fourier transform infrared spectroscopy, UV-Visible, and X-ray diffraction, ...Polyaniline (PANI)/silver composite was one-step synthesized under γ-ray irradiation. The structure of the composite was characterized by Fourier transform infrared spectroscopy, UV-Visible, and X-ray diffraction, which indicated that PANI and face-centered-cubic silver were synthesized under γ-ray irradiation. The reaction mechanism were discussed, which revealed that the PANI was formed by the reaction of aniline cation radicals formed by the reaction of aniline cation and -OH, and Ag was formed by the reaction of Ag+ and eaq. The morphology of the composite consisted of PANI nanofibers and Ag nanoparticles, and the mechanism of the morphology formation was discussed, which revealed that the rapid mixing like polymerization process might play an important role. It was revealed that the transport behavior of the composite well fitted with the variable-range-hopping model in 80-300 K and deviated from the model below 80 K.展开更多
A facile method to fabricate wettability pattern(two extreme wettabilities arranged in a pattern)to realize water self-pumping is proposed on cemented carbide while not necessarily depositing other materials on substr...A facile method to fabricate wettability pattern(two extreme wettabilities arranged in a pattern)to realize water self-pumping is proposed on cemented carbide while not necessarily depositing other materials on substrate surface.The water self-pumping is achieved by arranging wedge shaped superhydrophilic domain in superhydrophobic substrate using laser machining.Through single factor experiments,it is found that the key to the extreme wettabilities,micro⁃and nano⁃structures,is rendered by laser machining processes and is influenced by laser parameters.Meanwhile,the proper laser parameters that are used to fabricate required micro-and nano⁃structures are obtained.Finally,the water transport experiment is carried out,which shows that the velocity of water bulge could be up to 362 mm/s when the wedge angle is 3°.The mechanism of the water self-pumping is analyzed and it is found that the migration of water bulge is governed by Laplace pressure of the water bulge induced by the wedge micro-groove.展开更多
We have developed a simple, productive, and ettectlve poly(cllmetnysltoxane) rranu fer method to fabricate highly conductive Pd nanowires following DNA scaffolds on various substrates, based on ethanolreduction at l...We have developed a simple, productive, and ettectlve poly(cllmetnysltoxane) rranu fer method to fabricate highly conductive Pd nanowires following DNA scaffolds on various substrates, based on ethanolreduction at low temperature. Pd nanoparticles were selectively deposited and confined onto the DNA templates on a PDMS sheet to form Pd nanowires and then the nanowires were transferred to other various substrates with a low occurrence of par asitic nanoparticles. The structure, morphology and the conductance of Pd nanowires were characterized with transmission electron microscopy, field emission scanning electron mi croscopy, and electrical transport measurement, respectively. Moreover, the growth process of the Pd nanowires was investigated by varying the incubation time and reaction temper ature. The present strategy provides a new method to fabricate extremely dense, highly conductive, and well aligned Pd nanowires on various substrates, which make it promising for building nanosensors and nanoelectronic devices.展开更多
In this paper,we propose a cooperative spectrum sharing strategy based on the Nash bargaining solution.Specifically,the primary system leases a fraction of its transmission time to the secondary system in exchange for...In this paper,we propose a cooperative spectrum sharing strategy based on the Nash bargaining solution.Specifically,the primary system leases a fraction of its transmission time to the secondary system in exchange for cooperation to improve its transmission performance.To gain access to the spectrum of the primary system,the secondary system needs to split a fraction of its transmission bandwidth to help to forward the primary signal.As a reward,the secondary system can use the remaining bandwidth to transmit its own signal.We find a unique solution for this time and bandwidth allocation using the Nash bargaining solution.Simulation results demonstrate that the performance of the primary and secondary systems can both be improved by the proposed spectrum sharing strategy.展开更多
A research group at the University of Botswana has been investigating how culture and construction delivery system stability affect the Botswana construction industry performance. The government of Botswana is attempt...A research group at the University of Botswana has been investigating how culture and construction delivery system stability affect the Botswana construction industry performance. The government of Botswana is attempting to increase the construction performance and sustainability of the Botswana construction industry in an environment of local contractors who do not seem to have the expertise and experience. Currently, the Botswana industry is heavily dependent on foreign contractors. The researchers are trying to identify if the problem is the underdeveloped industry and Botswana culture, or potentially the combination of culture and unstable delivery system, and can a stable delivery system raise the performance of Botswana contractors. The two potential areas of interest are the country culture, and the project delivery/management model. The authors are using deductive logic, logical and simplistic models, and dominant or extreme information to minimizing the need to get into a long drawn out study of details which may be difficult to obtain and not necessarily solve the issue. The objective of the paper is to identify the best method to increase the performance of the construction industry, addressing both the cultural and delivery system problems. The preliminary measurement of the success of the solution is the acceptance of the concepts by major users in Botswana. This paper will propose the potential solution, which will be tested starting January 2011. If this solution is valid, it has a tremendous potential in underdeveloped countries.展开更多
The current demand growth of new components capable of operating at high power, high frequency, high temperatures and convergence towards miniaturization has lead to the development of new fields of nanotechnology bas...The current demand growth of new components capable of operating at high power, high frequency, high temperatures and convergence towards miniaturization has lead to the development of new fields of nanotechnology based on II-VI semiconductor Interest in nanostructure:s based on II-VI semiconductor narrow gap containing mercury (such as super lattices HgTe/CdTe) was due to their advantages over alloys with cadmium telluride Mercury (MCT: HgCdTe). The ternary alloy is a semiconductor band-gap direct, in that work the main interest is about the ternary compound. The results obtained are very satisfactory, they are compared with experimental results, and are in good agreement. These results are very promising and open new perspectives for the realization of solar cells and applications in the field of sensors.展开更多
Modeled with a three-level-atom appropriate to 980 nm pumped amplifiers,analytical solutions have been deduced for the rate equations of erbium-doped fiber amplifiers.Various key parameters of the amplifiers have been...Modeled with a three-level-atom appropriate to 980 nm pumped amplifiers,analytical solutions have been deduced for the rate equations of erbium-doped fiber amplifiers.Various key parameters of the amplifiers have been specified.展开更多
Defect-based engineering of carbon nanostructures is becoming an important and powerful method to modify the electron transport properties in graphene nanoribbon FETs. In this paper, the impact of the position and sym...Defect-based engineering of carbon nanostructures is becoming an important and powerful method to modify the electron transport properties in graphene nanoribbon FETs. In this paper, the impact of the position and symmetry of the ISTW defect on the performance of low dimensional 9AGNR double-gate graphene nanoribbon FET (DG-GNRFET) is investigated. Analyzing the transmission spectra, density of states and current-voltage characteristics shows that the defect effect on the electron transport is considerably varied depending on the positions and the orientations (the symmetric and asymmetric configuration) of the ISTW defect in the channel length. Based on the results, the asymmetric ISTW defect leads to a more controllability of the gate voltages over drain current, and drain current increases more than 5 times. The results have also con rmed the ISTW defect engineering potential on controlling the channel electrical current of DG-AGNR FET.展开更多
The absorption process of radiative heat in its transmission medium and the effect of ultra-attenuation on the radiative characteristics are analyzed in detail. A method of ultra-attenuation to enhance the radiative c...The absorption process of radiative heat in its transmission medium and the effect of ultra-attenuation on the radiative characteristics are analyzed in detail. A method of ultra-attenuation to enhance the radiative characteristics of the medium is proposed. It is proved that decreasing the particle size of coatings can increase the transmission depth of radiative heat and get higher emissivity and absorptivity both theoretically and practically. Ultra-attenuation and nanocrystallization will bring a brilliant prospect to the development of radiative coatings.展开更多
The flow behavior of pressure-driven water infiltration through graphene-based slit nanopores has been studied by molecular simulation.The simulated flow rate is close to the experimental values,which demonstrates the...The flow behavior of pressure-driven water infiltration through graphene-based slit nanopores has been studied by molecular simulation.The simulated flow rate is close to the experimental values,which demonstrates the reasonability of simulation results.Water molecules can spontaneously infiltrate into the nanopores,but an external driving force is generally required to pass through the whole pores.The exit of nanopore has a large obstruction on the water effusion.The flow velocity within the graphene nanochannels does not display monotonous dependence upon the pore width,indicating that the flow is related to the microscopic structures of water confined in the nanopores.Extensive structures of confined water are characterized in order to understand the flow behavior.This simulation improves the understanding of graphene-based nanofluidics,which helps in developing a new type of membrane separation technique.展开更多
Flexible strain sensor devices were fabricated by depositing Pd nanoclusters on PET membranes patterned with interdigital electrodes. The sensors responded to the deformation of the PET membranes with the conductance ...Flexible strain sensor devices were fabricated by depositing Pd nanoclusters on PET membranes patterned with interdigital electrodes. The sensors responded to the deformation of the PET membranes with the conductance changes of the nanocluster films and were characterized by both high gauge factor and wide detection range. The response characteristics of the strain sensors were found to depend strongly on the nanocluster coverage, which was attributed to the percolative nature of the electron transport in the closely spaced nanocluster arrays. By controlling the nanocluster deposition process, a strain sensor composed of nanocluster arrays with a coverage close to the effective percolation threshold was fabricated. The sensor device showed a linear response with a stable gauge factor of 55 for the applied strains from the lower detection limit up to 0.3%. At higher applied strains, a gauge factor as high as 200 was shown. The nanocluster films also demonstrated the ability to response to large deformations up to 8% applied strain, with an extremely high gauge factor of 3500.展开更多
Electron relaxation time and density of states near the Fermi level were calculated for "dirty" carbon nanotubes taking into account multiple elastic electrons scattering on impurities and structural inhomogeneities...Electron relaxation time and density of states near the Fermi level were calculated for "dirty" carbon nanotubes taking into account multiple elastic electrons scattering on impurities and structural inhomogeneities of a short-range order type. A possible explanation of low-temperature behavior of density of states and electrical conductivity depending on defect structure, impurities and chirality is presented.展开更多
Metallic ring-shaped nanotube arrays are proposed and its optical transmission properties are studied by using finite-difference time-domain (FDTD) method. Compared with the transmission spectra of conventional circ...Metallic ring-shaped nanotube arrays are proposed and its optical transmission properties are studied by using finite-difference time-domain (FDTD) method. Compared with the transmission spectra of conventional circular nanotube arrays, two photonic band gaps are emerged in the transmission spectra offing-shaped nanotube arrays, the two band gaps and transmission spectra are adjusted by the length, inner radius, intertube spacing and the dielectric constants of the core and embedding medium, and magnitude modification, redshift and blueshift of the resonance modes are observed. A metallic ring-shaped nanotube arrays for subwavelength band-stop filter in the range of visible light can be achieved. To understand its physical origin, field-interference mechanism was suggested by the field distributions. The proposed nanostructures and results may have great potential applications in subwavelength near-field optics.展开更多
In recent years, organic-inorganic hybrid nanocarriers are explored for effective drug delivery and preferable disease treatments. In this study, using 5-fluorouracil(5-FU)as electronegative model drug, a new type of ...In recent years, organic-inorganic hybrid nanocarriers are explored for effective drug delivery and preferable disease treatments. In this study, using 5-fluorouracil(5-FU)as electronegative model drug, a new type of organic-inorganic hybrid drug delivery system(LDH/HA-PEG/5-FU)was conceived and manufactured by the adsorption of PEGylated hyaluronic acid(HA-PEG)on the surface of layered double hydroxide(LDH, prepared via hydrothermal method)and the intercalation of 5-FU in the interlamination of LDH via ion exchange strategy. The drug loading amount of LDH/HA-PEG/5-FU achieved as high as 34.2%. LDH, LDH/5-FU and LDH/HA-PEG/5-FU were characterized by FT-IR, XRD, TGA, laser particle size analyzer and SEM. With the benefit of p Hdegradable feature of LDH and enzyme-degradable feature of HA, LDH/HA-PEG/5-FU showed p H-degradable and enzyme-degradable capacity in in vitro drug release. Moreover, the drug carrier LDH/HA-PEG contained biocompatible PEG and tumor-targeted HA, resulting in lower cytotoxicity and better endocytosis compared with LDH in vitro. It was suggested that the organic-inorganic hybrid drug delivery system, which was endowed with the properties of controlled release, low toxicity and tumor-targeting delivery for ameliorative cancer therapy, was advisable and might be applied further to fulfill other treatments.展开更多
In this work, enhancement of the light extraction efficiency of a 590 nm AIGaInP light-emitting diodes (LED) with a reflective top electrode (RTE) was investigated. A distributed Bragg reflector (DBR), consistin...In this work, enhancement of the light extraction efficiency of a 590 nm AIGaInP light-emitting diodes (LED) with a reflective top electrode (RTE) was investigated. A distributed Bragg reflector (DBR), consisting of AIAs/AIGaAs pairs, grown on an AlGaInP structure was used as a reflector for a reflective top electrode. It was found that a higher output power was observed from the AIGalnP LED with a RTE than from a conventional one. In addition, it was noted that the improvement in the output power depends strongly on the reflectivity of the reflector and that it exhibits a more effective performance with low injection currents. The increase in the optical output power was attributed to the enhanced extraction efficiency caused by a reduction of light absorbed from the emission region to top electrode through the RTE.展开更多
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.60736005 and No.60425101-1), the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No.60721001), the Provincial Program (No.9140A02060609DZ0208), the Program for New Century Excellent Talents in University (No.NCET- 06-0812), the Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (No.GGRYJJ08P 05), and the Young Excellence Project of Sichuan (No.09ZQ026-074).
文摘The role of bathophenanthroline (Bphen) as a buffer layer inserted between fullerene (C60) and Ag cathode in organic photovoltaic (OPV) cell was discussed. By introducing Bphen as a buffer layer with thicknes from 0 to 2.5 nm, the power conversion efficiency of the OPV cell based on copper phthalocyanine (CuPc) and C60 was increased from 0.87% to 2.25% under AM 1.5 solar illumination at an intensity of 100 mW/cm^2, which was higher than that of bathocuproine used as a buffer layer. The photocurrent-voltage characteristics showed that Bphen effectively improves electron transport through C60 layer into Ag electrode and leads to balance charge carrier transport capability. The influence of Bphen thickness on OPV cells was also investigated. Furthermore, the absorption spectrum shows that an additional Bphen layer enhances the light harvest capability of CuPc/C60.
基金The National Basic Research Program of China(973Program)(No.2011CB707600)the National Natural Science Founda tion of China(No.51435003,51375092)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20160935)the Natural Science Foundation of Higher Education Institutions of Jiangsu Province(No.16KJB460015)
文摘The model of ion transportation through graphene nanochannels is established by the molecular dynamics simulation method. Statistics of the electric potential and charge distribution are made, respectively, on both sides of graphene nanopore with various diameters. Then, their changing relationship with respect to the nanopore diameter is determined. When applying a uniform electric field, polar water molecules are rearranged so that the corresponding relationship between the polarized degree of these molecules and the nanopore diameter can be created. Based on the theoretical model of ion transportation through nanochannels,the changing relationship between the concentration of anions/cations in nanochannels and bulk solution concentration is quantitatively analyzed. The results show that the increase of potential drop and charge accumulation, as well as a more obvious water polarization, will occur with the decrease of nanopore diameter. In addition, hydrogen ion concentration has a large proportion in nanochannels with a sodium chloride(NaCl) solution at a relative low concentration. As the NaCl concentration increases, the concentration appreciation of sodium ions tends to be far greater than the concentration drop of chloride ions. Therefore, sodium ion concentration makes more contribution to ionic conductance.
基金Supported by the Major Program of the National Natural Science Foundation of China(10632070)
文摘Transport of nanoparticles and coagulation is simulated with the combination of CFD in a circular bend. The Taylor-expansion moment method(TEMOM)is employed to study dynamics of nanoparticles with Brownian motion,based on the flow field from numerical simulation.A fully developed flow pattern in the present simulation is compared with previous numerical results for validating the model and computational code.It is found that for the simulated particulate flow system,the particle mass concentration,number concentration,particle polydispersity, mean particle diameter and geometric standard deviation over cross-section increase with time.The distribution of particle mass concentration at different time is independent of the initial particle size.More particles are concen-trated at outer edge of the bend.Coagulation plays more important role at initial stage than that in the subsequent period.The increase of Reynolds number and initial particle size leads to the increase of particle number concentration.The particle polydispersity,mean particle diameter and geometric standard deviation increase with decreasing Reynolds number and initial particle size.
文摘Polyaniline (PANI)/silver composite was one-step synthesized under γ-ray irradiation. The structure of the composite was characterized by Fourier transform infrared spectroscopy, UV-Visible, and X-ray diffraction, which indicated that PANI and face-centered-cubic silver were synthesized under γ-ray irradiation. The reaction mechanism were discussed, which revealed that the PANI was formed by the reaction of aniline cation radicals formed by the reaction of aniline cation and -OH, and Ag was formed by the reaction of Ag+ and eaq. The morphology of the composite consisted of PANI nanofibers and Ag nanoparticles, and the mechanism of the morphology formation was discussed, which revealed that the rapid mixing like polymerization process might play an important role. It was revealed that the transport behavior of the composite well fitted with the variable-range-hopping model in 80-300 K and deviated from the model below 80 K.
基金the National Natural Science Foundation of China(No.51875285)the Natural Science Foundation of Jiangsu Province(No.BK20190066)+1 种基金the Fundamental Research Funds for the Central Universities(No.NE2020005)the Foundation of the Graduate Innovation Center,Nanjing University of Aeronautics and Astronautics(No.kfjj20190508).
文摘A facile method to fabricate wettability pattern(two extreme wettabilities arranged in a pattern)to realize water self-pumping is proposed on cemented carbide while not necessarily depositing other materials on substrate surface.The water self-pumping is achieved by arranging wedge shaped superhydrophilic domain in superhydrophobic substrate using laser machining.Through single factor experiments,it is found that the key to the extreme wettabilities,micro⁃and nano⁃structures,is rendered by laser machining processes and is influenced by laser parameters.Meanwhile,the proper laser parameters that are used to fabricate required micro-and nano⁃structures are obtained.Finally,the water transport experiment is carried out,which shows that the velocity of water bulge could be up to 362 mm/s when the wedge angle is 3°.The mechanism of the water self-pumping is analyzed and it is found that the migration of water bulge is governed by Laplace pressure of the water bulge induced by the wedge micro-groove.
文摘We have developed a simple, productive, and ettectlve poly(cllmetnysltoxane) rranu fer method to fabricate highly conductive Pd nanowires following DNA scaffolds on various substrates, based on ethanolreduction at low temperature. Pd nanoparticles were selectively deposited and confined onto the DNA templates on a PDMS sheet to form Pd nanowires and then the nanowires were transferred to other various substrates with a low occurrence of par asitic nanoparticles. The structure, morphology and the conductance of Pd nanowires were characterized with transmission electron microscopy, field emission scanning electron mi croscopy, and electrical transport measurement, respectively. Moreover, the growth process of the Pd nanowires was investigated by varying the incubation time and reaction temper ature. The present strategy provides a new method to fabricate extremely dense, highly conductive, and well aligned Pd nanowires on various substrates, which make it promising for building nanosensors and nanoelectronic devices.
基金supported by the National Natural Science Foundation of China under Grants No.61372087,No.61303235the Zhejiang Leading Team of Science and Technology Innovation on Modem Communication and Network System under Grant No.2010R50011the Project of the Zhejiang Provincial Science and Technology Department under Grant No.Y201329389
文摘In this paper,we propose a cooperative spectrum sharing strategy based on the Nash bargaining solution.Specifically,the primary system leases a fraction of its transmission time to the secondary system in exchange for cooperation to improve its transmission performance.To gain access to the spectrum of the primary system,the secondary system needs to split a fraction of its transmission bandwidth to help to forward the primary signal.As a reward,the secondary system can use the remaining bandwidth to transmit its own signal.We find a unique solution for this time and bandwidth allocation using the Nash bargaining solution.Simulation results demonstrate that the performance of the primary and secondary systems can both be improved by the proposed spectrum sharing strategy.
文摘A research group at the University of Botswana has been investigating how culture and construction delivery system stability affect the Botswana construction industry performance. The government of Botswana is attempting to increase the construction performance and sustainability of the Botswana construction industry in an environment of local contractors who do not seem to have the expertise and experience. Currently, the Botswana industry is heavily dependent on foreign contractors. The researchers are trying to identify if the problem is the underdeveloped industry and Botswana culture, or potentially the combination of culture and unstable delivery system, and can a stable delivery system raise the performance of Botswana contractors. The two potential areas of interest are the country culture, and the project delivery/management model. The authors are using deductive logic, logical and simplistic models, and dominant or extreme information to minimizing the need to get into a long drawn out study of details which may be difficult to obtain and not necessarily solve the issue. The objective of the paper is to identify the best method to increase the performance of the construction industry, addressing both the cultural and delivery system problems. The preliminary measurement of the success of the solution is the acceptance of the concepts by major users in Botswana. This paper will propose the potential solution, which will be tested starting January 2011. If this solution is valid, it has a tremendous potential in underdeveloped countries.
文摘The current demand growth of new components capable of operating at high power, high frequency, high temperatures and convergence towards miniaturization has lead to the development of new fields of nanotechnology based on II-VI semiconductor Interest in nanostructure:s based on II-VI semiconductor narrow gap containing mercury (such as super lattices HgTe/CdTe) was due to their advantages over alloys with cadmium telluride Mercury (MCT: HgCdTe). The ternary alloy is a semiconductor band-gap direct, in that work the main interest is about the ternary compound. The results obtained are very satisfactory, they are compared with experimental results, and are in good agreement. These results are very promising and open new perspectives for the realization of solar cells and applications in the field of sensors.
文摘Modeled with a three-level-atom appropriate to 980 nm pumped amplifiers,analytical solutions have been deduced for the rate equations of erbium-doped fiber amplifiers.Various key parameters of the amplifiers have been specified.
文摘Defect-based engineering of carbon nanostructures is becoming an important and powerful method to modify the electron transport properties in graphene nanoribbon FETs. In this paper, the impact of the position and symmetry of the ISTW defect on the performance of low dimensional 9AGNR double-gate graphene nanoribbon FET (DG-GNRFET) is investigated. Analyzing the transmission spectra, density of states and current-voltage characteristics shows that the defect effect on the electron transport is considerably varied depending on the positions and the orientations (the symmetric and asymmetric configuration) of the ISTW defect in the channel length. Based on the results, the asymmetric ISTW defect leads to a more controllability of the gate voltages over drain current, and drain current increases more than 5 times. The results have also con rmed the ISTW defect engineering potential on controlling the channel electrical current of DG-AGNR FET.
文摘The absorption process of radiative heat in its transmission medium and the effect of ultra-attenuation on the radiative characteristics are analyzed in detail. A method of ultra-attenuation to enhance the radiative characteristics of the medium is proposed. It is proved that decreasing the particle size of coatings can increase the transmission depth of radiative heat and get higher emissivity and absorptivity both theoretically and practically. Ultra-attenuation and nanocrystallization will bring a brilliant prospect to the development of radiative coatings.
基金Supported by the National Natural Science Foundation of China(21376116)A PAPD Project of Jiangsu Higher Education Institution
文摘The flow behavior of pressure-driven water infiltration through graphene-based slit nanopores has been studied by molecular simulation.The simulated flow rate is close to the experimental values,which demonstrates the reasonability of simulation results.Water molecules can spontaneously infiltrate into the nanopores,but an external driving force is generally required to pass through the whole pores.The exit of nanopore has a large obstruction on the water effusion.The flow velocity within the graphene nanochannels does not display monotonous dependence upon the pore width,indicating that the flow is related to the microscopic structures of water confined in the nanopores.Extensive structures of confined water are characterized in order to understand the flow behavior.This simulation improves the understanding of graphene-based nanofluidics,which helps in developing a new type of membrane separation technique.
基金supported by the National Natural Science Foundation of China(No.11627806)a Project funded by the Priority Academic Programme Development of Jiangsu Higher Education Institutions
文摘Flexible strain sensor devices were fabricated by depositing Pd nanoclusters on PET membranes patterned with interdigital electrodes. The sensors responded to the deformation of the PET membranes with the conductance changes of the nanocluster films and were characterized by both high gauge factor and wide detection range. The response characteristics of the strain sensors were found to depend strongly on the nanocluster coverage, which was attributed to the percolative nature of the electron transport in the closely spaced nanocluster arrays. By controlling the nanocluster deposition process, a strain sensor composed of nanocluster arrays with a coverage close to the effective percolation threshold was fabricated. The sensor device showed a linear response with a stable gauge factor of 55 for the applied strains from the lower detection limit up to 0.3%. At higher applied strains, a gauge factor as high as 200 was shown. The nanocluster films also demonstrated the ability to response to large deformations up to 8% applied strain, with an extremely high gauge factor of 3500.
文摘Electron relaxation time and density of states near the Fermi level were calculated for "dirty" carbon nanotubes taking into account multiple elastic electrons scattering on impurities and structural inhomogeneities of a short-range order type. A possible explanation of low-temperature behavior of density of states and electrical conductivity depending on defect structure, impurities and chirality is presented.
基金Projects(11164007,61275174)supported by the National Natural Science Foundation of ChinaProject(20100162110068)supported by the Doctoral Program of Higher Education of China+1 种基金Project(20132BAB212007)supported by the Natural Science Foundation of Jiangxi Province,ChinaProject(GJJ11107)supported by Scientific Foundation of Jiangxi Education Department,China
文摘Metallic ring-shaped nanotube arrays are proposed and its optical transmission properties are studied by using finite-difference time-domain (FDTD) method. Compared with the transmission spectra of conventional circular nanotube arrays, two photonic band gaps are emerged in the transmission spectra offing-shaped nanotube arrays, the two band gaps and transmission spectra are adjusted by the length, inner radius, intertube spacing and the dielectric constants of the core and embedding medium, and magnitude modification, redshift and blueshift of the resonance modes are observed. A metallic ring-shaped nanotube arrays for subwavelength band-stop filter in the range of visible light can be achieved. To understand its physical origin, field-interference mechanism was suggested by the field distributions. The proposed nanostructures and results may have great potential applications in subwavelength near-field optics.
基金Supported by the National Natural Science Foundation of China(No.81371667,No.31271073)
文摘In recent years, organic-inorganic hybrid nanocarriers are explored for effective drug delivery and preferable disease treatments. In this study, using 5-fluorouracil(5-FU)as electronegative model drug, a new type of organic-inorganic hybrid drug delivery system(LDH/HA-PEG/5-FU)was conceived and manufactured by the adsorption of PEGylated hyaluronic acid(HA-PEG)on the surface of layered double hydroxide(LDH, prepared via hydrothermal method)and the intercalation of 5-FU in the interlamination of LDH via ion exchange strategy. The drug loading amount of LDH/HA-PEG/5-FU achieved as high as 34.2%. LDH, LDH/5-FU and LDH/HA-PEG/5-FU were characterized by FT-IR, XRD, TGA, laser particle size analyzer and SEM. With the benefit of p Hdegradable feature of LDH and enzyme-degradable feature of HA, LDH/HA-PEG/5-FU showed p H-degradable and enzyme-degradable capacity in in vitro drug release. Moreover, the drug carrier LDH/HA-PEG contained biocompatible PEG and tumor-targeted HA, resulting in lower cytotoxicity and better endocytosis compared with LDH in vitro. It was suggested that the organic-inorganic hybrid drug delivery system, which was endowed with the properties of controlled release, low toxicity and tumor-targeting delivery for ameliorative cancer therapy, was advisable and might be applied further to fulfill other treatments.
文摘In this work, enhancement of the light extraction efficiency of a 590 nm AIGaInP light-emitting diodes (LED) with a reflective top electrode (RTE) was investigated. A distributed Bragg reflector (DBR), consisting of AIAs/AIGaAs pairs, grown on an AlGaInP structure was used as a reflector for a reflective top electrode. It was found that a higher output power was observed from the AIGalnP LED with a RTE than from a conventional one. In addition, it was noted that the improvement in the output power depends strongly on the reflectivity of the reflector and that it exhibits a more effective performance with low injection currents. The increase in the optical output power was attributed to the enhanced extraction efficiency caused by a reduction of light absorbed from the emission region to top electrode through the RTE.