The air route network, which supports all the flight activities of the civil aviation, is the most fundamental infrastructure of air traffic management system. In this paper, we study the Chinese air route network (C...The air route network, which supports all the flight activities of the civil aviation, is the most fundamental infrastructure of air traffic management system. In this paper, we study the Chinese air route network (CARN) within the framework of complex networks. We find that CARN is a geographical network possessing exponential degree distribution, low clustering coefficient, large shortest path length and exponential spatial distance distribution that is obviously different from that of the Chinese airport network (CAN). Besides, via investigating the flight data from 2002 to 2010, we demonstrate that the topology structure of CARN is homogeneous, howbeit the distribution of flight flow on CARN is rather heterogeneous. In addition, the traffic on CARN keeps growing in an exponential form and the increasing speed of west China is remarkably larger than that of east China. Our work will be helpful to better understand Chinese air traffic systems.展开更多
Complex networks have been studied across many fields of science in recent years. In this paper, we give a brief introduction of networks, then follow the original works by Tsonis et al (2004, 2006) starting with da...Complex networks have been studied across many fields of science in recent years. In this paper, we give a brief introduction of networks, then follow the original works by Tsonis et al (2004, 2006) starting with data of the surface temperature from 160 Chinese weather observations to investigate the topology of Chinese climate networks. Results show that the Chinese climate network exhibits a characteristic of regular, almost fully connected networks, which means that most nodes in this case have the same number of links, and so-called super nodes with a very large number of links do not exist there. In other words, though former results show that nodes in the extratropical region provide a property of scale-free networks, they still have other different local fine structures inside. We also detect the community of the Chinese climate network by using a Bayesian technique; the effective number of communities of the Chinese climate network is about four in this network. More importantly, this technique approaches results in divisions which have connections with physics and dynamics; the division into communities may highlight the aspects of the dynamics of climate variability.展开更多
Starting from the background and significance of the development and design of the network course of traditional Chinese medicine pharmacy specialty formed by introducing Guangxi minority medicine,this paper discusses...Starting from the background and significance of the development and design of the network course of traditional Chinese medicine pharmacy specialty formed by introducing Guangxi minority medicine,this paper discusses the teaching design scheme and module construction of the network course in the development process,and summarizes the design,production and construction experience of the network course.Through practice,the teaching effect and achievement of the network course of traditional Chinese medicine pharmacy specialty formed by introducing Guangxi minority medicine are obvious.展开更多
The article analyzes the development of the Chinese Ecosystem Research Network, and its mission, mandate, and management mechanisms, with examples of research, demonstration and consultation for policy-setting.
Through empirical analysis of the global structure of the Worldwide Marine Transportation Network (WMTN), we find that the WMTN, a small-world network, exhibits an exponential-like degree distribution. We hereby inv...Through empirical analysis of the global structure of the Worldwide Marine Transportation Network (WMTN), we find that the WMTN, a small-world network, exhibits an exponential-like degree distribution. We hereby investigate the efficiency of the WMTN by employing a simple definition. Compared with many other transportation networks, the WMTN possesses relatively low efficiency. Furthermore, by exploring the relationship between the topological structure and the container throughput, we find that strong correlations exist among the container throughout the degree and the clustering coefficient. Also, considering the navigational process that a ship travels in a real shipping line, we obtain that the weight of a seaport is proportional to the total probability contributed by all the passing shipping lines.展开更多
A method of chaotic control on network traffic is presented. By this method, the chaotic network traffic can be controlled to a pre-assigned equilibrium point according to chaotic prediction and the largest Lyapunov e...A method of chaotic control on network traffic is presented. By this method, the chaotic network traffic can be controlled to a pre-assigned equilibrium point according to chaotic prediction and the largest Lyapunov exponent ofthe traffic on congested link is reduced, thereby the probability of traffic burst and network congestion can be reduced. Numerical examples show that this method is effective.展开更多
We study the perturbation to symmetries and adiabatic invariants of a generalized Birkhoff system. Based on the invariance of differential equations under infinitesimal transformations, Lie symmetries, laws of conserv...We study the perturbation to symmetries and adiabatic invariants of a generalized Birkhoff system. Based on the invariance of differential equations under infinitesimal transformations, Lie symmetries, laws of conservations, perturbation to the symmetries and adiabatic invariants of the generalized Birkhoff system are presented. First, the concepts of Lie symmetries and higher order adiabatic invariants of the generalized Birkhoff system are proposed. Then, the conditions for the existence of the exact invariants and adiabatic invariants are proved, and their forms are given. Finally, an example is presented to illustrate the method and results.展开更多
A thermodynamic cavitation model is developed to simulate the cavitating water flow in a wide temperature range. The thermal effect on bubble growth during cavitation is introduced in the developed model by considerin...A thermodynamic cavitation model is developed to simulate the cavitating water flow in a wide temperature range. The thermal effect on bubble growth during cavitation is introduced in the developed model by considering both pressure difference and heat transfer between the vapor and liquid phase. The cavitating turbulent flow over a NACA0015 hydrofoil has been simulated at various temperatures from room temperature to 150°C by using the present cavitation model, which has been validated by the experimental data. It is seen that the thermodynamic effects of cavitation, vapor depression and temperature depression are much more predominant in high temperature water compared with those in room temperature water. These results indicate that the proposed thermodynamic cavitation model is reasonably applicable to the cavitating water flow in a wide temperature range.展开更多
Recently, collaborative tagging systems have attracted more and more attention and have been wlaely appnea in web systems. Tags provide highly abstracted information about personal preferences and item content, and th...Recently, collaborative tagging systems have attracted more and more attention and have been wlaely appnea in web systems. Tags provide highly abstracted information about personal preferences and item content, and therefore have the potential to help in improving better personalized recommendations, We propose a diffusion- based recommendation algorithm considering the personal vocabulary and evaluate it in a real-world dataset: Del.icio.us. Experimental results demonstrate that the usage of tag information can significantly improve the accuracy of personalized recommendations.展开更多
Levitation stability is a crucial factor that influences acoustic levitation capability. We present two sample-including models for a single-axis acoustic levitator with either a rigid or elastic reflector. Numerical ...Levitation stability is a crucial factor that influences acoustic levitation capability. We present two sample-including models for a single-axis acoustic levitator with either a rigid or elastic reflector. Numerical analysis shows that, with the rigid reflector, both the decay time from initial disturbance and the vibration amplitude increase with sample density, which is unfavorable for levitation stability. However, with the elastic reflector, the decay time and the vibration amplitude are greatly reduced by choosing appropriate parameters of the reflector. Experimental results agree well with theoretical predictions, indicating that levitation stability can be remarkably enhanced by replacing the rigid reflector with an elastic reflector.展开更多
Sb is a classic material of a super-resolution near field structure (super-RENS) mask layer in which the optical switch formation is often realized by nanosecond laser pulse stimulation. We achieve fast and repeatab...Sb is a classic material of a super-resolution near field structure (super-RENS) mask layer in which the optical switch formation is often realized by nanosecond laser pulse stimulation. We achieve fast and repeatable optical switching driven by picosecond laser pulses in a proper fluence range on Sb thin films. The optical properties of Sb thin films before and after switching are studied by surface-sensitive micro-area ellipsometry. The change of optical constants after switching is less than 2% in the whole visible range. The Sb mask layer is shown to be very promising for ultrafast super-resolution optical storage applications.展开更多
A fractal dimension for roughness height (RH) is introduced to characterize the degree of roughness or disorder of particle surface characters which significantly influence physical-chimerical processes in porous me...A fractal dimension for roughness height (RH) is introduced to characterize the degree of roughness or disorder of particle surface characters which significantly influence physical-chimerical processes in porous media. An analytical expression for the fractal dimension of RH on statistically self-similar fractal surfaces is derived and is expressed as a function of roughness parameters. The specific surface area (SSA) of porous materials with spherical particles is also derived, and the proposed fractal model for the SSA of particles with rough surfaces is expressed as a function of fractal dimension for RH and fractal dimension for particle size distribution, relative roughness of particle surface, and ratio of the minimum to the maximum particle diameters of spherical particles.展开更多
We propose a scheme to teleport an unknown single-qubit state by using a high-dimensional entangled state as the quantum channel. As a special case, a scheme for teleportation of an unknown single-qubit state via thre...We propose a scheme to teleport an unknown single-qubit state by using a high-dimensional entangled state as the quantum channel. As a special case, a scheme for teleportation of an unknown single-qubit state via three-dimensional entangled state is investigated in detail. Also, this scheme can be directly generalized to an unknown f-dimensional state by using a d-dimensional entangled state (d〉f) as the quantum channel.展开更多
We report on the evaluation of thermal degradation damage in metal material using the nonlinear effect of Lamb wave propagation. A mountain-shape'' change in the second harmonic of Lamb wave propagation versus the l...We report on the evaluation of thermal degradation damage in metal material using the nonlinear effect of Lamb wave propagation. A mountain-shape'' change in the second harmonic of Lamb wave propagation versus the level of thermal degradation in the specimens is observed. It is attributed to the precipitations in the early stage and the microvoids after long-term service in terms of metallographic studies. The results show that the nonlinear Lamb wave is very sensitive to the microstructure evolution and is a good potential for quantitative evaluation of the thermal damaged materials.展开更多
Within the framework of the density functional theory for classical fluids, the equilibrium density profiles of charged hard sphere fluid confined in micro-cavity are studied by means of the modified fundamental measu...Within the framework of the density functional theory for classical fluids, the equilibrium density profiles of charged hard sphere fluid confined in micro-cavity are studied by means of the modified fundamental measure theory. The dimension of micro-cavity, the charge of hard sphere and the applied electric field are found to have significant effects on the density profiles. In particular, it is shown that Coulomb interaction, excluded volume interaction and applied electric field play the central role in controlling the aggregated structure of the system.展开更多
We calculate the production of prompt and thermal photons which includes the contribution of gluons in relativistic heavy ion collisions with the equilibrium and non-equilibrium quark-gluon plasma. We develop a new th...We calculate the production of prompt and thermal photons which includes the contribution of gluons in relativistic heavy ion collisions with the equilibrium and non-equilibrium quark-gluon plasma. We develop a new thermal jet-photon conversion mechanism which plays a vital role in the low transverse momentum region. The effect of the non-equilibrium quark-gluon plasma enhances the contribution of the thermal photons. The shadowing and iso-spin of the nucleus which can properly estimate the prompt photon production are also considered in our calculation.展开更多
We present a design for a polarization insensitive metamaterial absorber at 9.5 GHz by utilizing properly arranged resonant unit cells with orthogonal polarization sensitivity. Full-wave electromagnetic simulation dem...We present a design for a polarization insensitive metamaterial absorber at 9.5 GHz by utilizing properly arranged resonant unit cells with orthogonal polarization sensitivity. Full-wave electromagnetic simulation demonstrates nearly perfect microwave absorption, which has been verified by experimental measurement with a maximum absorption of about 92% for incident wave with different polarizations. Furthermore, we find such a metamaterial thin absorber could work for a wide incident angle ranging from 0° to 50°with absorption no less than 80° for both the transverse electric mode and transverse magnetic mode.展开更多
Traditional Chinese medicine(TCM) holds a holistic theory, and specializes in balancing disordered human body using numerous natural products, particularly Chinese herbal formulae. TCM has certain treatment advantag...Traditional Chinese medicine(TCM) holds a holistic theory, and specializes in balancing disordered human body using numerous natural products, particularly Chinese herbal formulae. TCM has certain treatment advantages for patients suffering from various complex diseases. However, due to the complex nature of TCM, it remains difficult to unveil such holistic medicine by the current reductionism research strategies, which treat both herbal ingredients and targets in isolation. Recently, an emerging network pharmacology approach has been introduced to tackle this bottleneck problem. A TCM-derived novel therapeutic concept, "network target", which is different from the Western medicine's "onetarget" concept, has been proposed from China. The network target strategy is able to illustrate the complex interactions among the biological systems, drugs, and complex diseases from a network perspective, and thus provides an innovative approach to access ancient remedies in a precision manner and at a systematic level, which also highlights TCM's potential in current medical systems.展开更多
A low-cost photoconductive dual-band detector was prepared using a nanoporous ZnO film sensitized by PbS quantum dots (QDs). At room temperature the device shows a UV response in the wavelength range of 200-400 nm w...A low-cost photoconductive dual-band detector was prepared using a nanoporous ZnO film sensitized by PbS quantum dots (QDs). At room temperature the device shows a UV response in the wavelength range of 200-400 nm with a 370 nm peak responsivity of 4.0×105 V/W and a vis-NIR response from 500 to 1400 nm with a 700 nm peak responsivity of 5.4×105 V/W. By increasing the size of the PbS QD, the response can be extended up to 2.9 μm. It is suggested that the UV response is a result of interband absorption of UV radiation by ZnO and the IR response comes from the absorption of PbS QDs.展开更多
A method to measure the refractive index for high reflectance materials in the terahertz range with terahertz time domain reflection spectroscopy is proposed. In this method, the THz waveforms reflected by a silicon w...A method to measure the refractive index for high reflectance materials in the terahertz range with terahertz time domain reflection spectroscopy is proposed. In this method, the THz waveforms reflected by a silicon wafer and high reflectance sample are measured respectively. The refractive index of the silicon wafer, measured with the THz time domain transmission spectroscopy, is used as a reference in the THz time domain reflective spectroscopy. Therefore, the complex refractive index of the sample can be obtained by resorting to the known reflective index of the silicon and the Fresnel law. To improve the accuracy of the phase shift, the Kramers-Kronig transform is adopted. This method is also verified by the index of the silicon in THz reflection spectroscopy. The bulk metal plates have been taken as the sample, and the experimentally obtained metallic refractive indexes are compared with the simple Drude model.展开更多
基金supported by the National Basic Research Program of China (Grant No.2011CB707004)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No.60921001)+1 种基金the National Key Technologies R & D Program of China (Grant No.2011BAH24B02)the Fundamental Research Funds for the Central Universities
文摘The air route network, which supports all the flight activities of the civil aviation, is the most fundamental infrastructure of air traffic management system. In this paper, we study the Chinese air route network (CARN) within the framework of complex networks. We find that CARN is a geographical network possessing exponential degree distribution, low clustering coefficient, large shortest path length and exponential spatial distance distribution that is obviously different from that of the Chinese airport network (CAN). Besides, via investigating the flight data from 2002 to 2010, we demonstrate that the topology structure of CARN is homogeneous, howbeit the distribution of flight flow on CARN is rather heterogeneous. In addition, the traffic on CARN keeps growing in an exponential form and the increasing speed of west China is remarkably larger than that of east China. Our work will be helpful to better understand Chinese air traffic systems.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 40890052 and 40505018)
文摘Complex networks have been studied across many fields of science in recent years. In this paper, we give a brief introduction of networks, then follow the original works by Tsonis et al (2004, 2006) starting with data of the surface temperature from 160 Chinese weather observations to investigate the topology of Chinese climate networks. Results show that the Chinese climate network exhibits a characteristic of regular, almost fully connected networks, which means that most nodes in this case have the same number of links, and so-called super nodes with a very large number of links do not exist there. In other words, though former results show that nodes in the extratropical region provide a property of scale-free networks, they still have other different local fine structures inside. We also detect the community of the Chinese climate network by using a Bayesian technique; the effective number of communities of the Chinese climate network is about four in this network. More importantly, this technique approaches results in divisions which have connections with physics and dynamics; the division into communities may highlight the aspects of the dynamics of climate variability.
基金the"13 th Five-year"Plan Project of Guangxi Educational Science(2017B089).
文摘Starting from the background and significance of the development and design of the network course of traditional Chinese medicine pharmacy specialty formed by introducing Guangxi minority medicine,this paper discusses the teaching design scheme and module construction of the network course in the development process,and summarizes the design,production and construction experience of the network course.Through practice,the teaching effect and achievement of the network course of traditional Chinese medicine pharmacy specialty formed by introducing Guangxi minority medicine are obvious.
文摘The article analyzes the development of the Chinese Ecosystem Research Network, and its mission, mandate, and management mechanisms, with examples of research, demonstration and consultation for policy-setting.
基金Supported by the National Natural Science Foundation of China under Grant Nos 70571027, 10647125, 10635020 and 70401020, and the Program of Introducing Talents of Discipline to Universities under Grant No B08033.
文摘Through empirical analysis of the global structure of the Worldwide Marine Transportation Network (WMTN), we find that the WMTN, a small-world network, exhibits an exponential-like degree distribution. We hereby investigate the efficiency of the WMTN by employing a simple definition. Compared with many other transportation networks, the WMTN possesses relatively low efficiency. Furthermore, by exploring the relationship between the topological structure and the container throughput, we find that strong correlations exist among the container throughout the degree and the clustering coefficient. Also, considering the navigational process that a ship travels in a real shipping line, we obtain that the weight of a seaport is proportional to the total probability contributed by all the passing shipping lines.
文摘A method of chaotic control on network traffic is presented. By this method, the chaotic network traffic can be controlled to a pre-assigned equilibrium point according to chaotic prediction and the largest Lyapunov exponent ofthe traffic on congested link is reduced, thereby the probability of traffic burst and network congestion can be reduced. Numerical examples show that this method is effective.
基金Supported by the National Natural Science Foundation under Grant No 10972127, and the Natural Science Foundation of Henan Province under Grant Nos 082300410330 and 082300410370.
文摘We study the perturbation to symmetries and adiabatic invariants of a generalized Birkhoff system. Based on the invariance of differential equations under infinitesimal transformations, Lie symmetries, laws of conservations, perturbation to the symmetries and adiabatic invariants of the generalized Birkhoff system are presented. First, the concepts of Lie symmetries and higher order adiabatic invariants of the generalized Birkhoff system are proposed. Then, the conditions for the existence of the exact invariants and adiabatic invariants are proved, and their forms are given. Finally, an example is presented to illustrate the method and results.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50676044 and 10532010, and Beijing Natural Science Foundation under Grant No 3072008.
文摘A thermodynamic cavitation model is developed to simulate the cavitating water flow in a wide temperature range. The thermal effect on bubble growth during cavitation is introduced in the developed model by considering both pressure difference and heat transfer between the vapor and liquid phase. The cavitating turbulent flow over a NACA0015 hydrofoil has been simulated at various temperatures from room temperature to 150°C by using the present cavitation model, which has been validated by the experimental data. It is seen that the thermodynamic effects of cavitation, vapor depression and temperature depression are much more predominant in high temperature water compared with those in room temperature water. These results indicate that the proposed thermodynamic cavitation model is reasonably applicable to the cavitating water flow in a wide temperature range.
基金Supported by China Postdoctoral Science Foundation (20080431273), the National Natural Science Foundation of China under Grant Nos 60973069 and 90924011, and the Swiss National Science Foundation (200020-121848).
文摘Recently, collaborative tagging systems have attracted more and more attention and have been wlaely appnea in web systems. Tags provide highly abstracted information about personal preferences and item content, and therefore have the potential to help in improving better personalized recommendations, We propose a diffusion- based recommendation algorithm considering the personal vocabulary and evaluate it in a real-world dataset: Del.icio.us. Experimental results demonstrate that the usage of tag information can significantly improve the accuracy of personalized recommendations.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50121101, 50395105 and 50301012, and the Foundation for the Author of National Excellent Doctoral Dissertation of China.
文摘Levitation stability is a crucial factor that influences acoustic levitation capability. We present two sample-including models for a single-axis acoustic levitator with either a rigid or elastic reflector. Numerical analysis shows that, with the rigid reflector, both the decay time from initial disturbance and the vibration amplitude increase with sample density, which is unfavorable for levitation stability. However, with the elastic reflector, the decay time and the vibration amplitude are greatly reduced by choosing appropriate parameters of the reflector. Experimental results agree well with theoretical predictions, indicating that levitation stability can be remarkably enhanced by replacing the rigid reflector with an elastic reflector.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50872139, 10874247, 60644002 and 60678009, the National Basic Research Program of China (2007CB935402), and Chinese Academy of Sciences (KJCX2-YW-M06).
文摘Sb is a classic material of a super-resolution near field structure (super-RENS) mask layer in which the optical switch formation is often realized by nanosecond laser pulse stimulation. We achieve fast and repeatable optical switching driven by picosecond laser pulses in a proper fluence range on Sb thin films. The optical properties of Sb thin films before and after switching are studied by surface-sensitive micro-area ellipsometry. The change of optical constants after switching is less than 2% in the whole visible range. The Sb mask layer is shown to be very promising for ultrafast super-resolution optical storage applications.
基金Supported by the National Natural Science Foundation of China under Grant No 10932010.
文摘A fractal dimension for roughness height (RH) is introduced to characterize the degree of roughness or disorder of particle surface characters which significantly influence physical-chimerical processes in porous media. An analytical expression for the fractal dimension of RH on statistically self-similar fractal surfaces is derived and is expressed as a function of roughness parameters. The specific surface area (SSA) of porous materials with spherical particles is also derived, and the proposed fractal model for the SSA of particles with rough surfaces is expressed as a function of fractal dimension for RH and fractal dimension for particle size distribution, relative roughness of particle surface, and ratio of the minimum to the maximum particle diameters of spherical particles.
文摘We propose a scheme to teleport an unknown single-qubit state by using a high-dimensional entangled state as the quantum channel. As a special case, a scheme for teleportation of an unknown single-qubit state via three-dimensional entangled state is investigated in detail. Also, this scheme can be directly generalized to an unknown f-dimensional state by using a d-dimensional entangled state (d〉f) as the quantum channel.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50835003 and 10674180, the Program for NCET under Grant No 06-0414 and the Shanghai Leading Academic Discipline Project (No B503).
文摘We report on the evaluation of thermal degradation damage in metal material using the nonlinear effect of Lamb wave propagation. A mountain-shape'' change in the second harmonic of Lamb wave propagation versus the level of thermal degradation in the specimens is observed. It is attributed to the precipitations in the early stage and the microvoids after long-term service in terms of metallographic studies. The results show that the nonlinear Lamb wave is very sensitive to the microstructure evolution and is a good potential for quantitative evaluation of the thermal damaged materials.
基金Supported by the National Natural Science Foundation of China under Grant No 20873035.
文摘Within the framework of the density functional theory for classical fluids, the equilibrium density profiles of charged hard sphere fluid confined in micro-cavity are studied by means of the modified fundamental measure theory. The dimension of micro-cavity, the charge of hard sphere and the applied electric field are found to have significant effects on the density profiles. In particular, it is shown that Coulomb interaction, excluded volume interaction and applied electric field play the central role in controlling the aggregated structure of the system.
基金Supported by the National Natural Science Foundation of China under Grant No 10665003.
文摘We calculate the production of prompt and thermal photons which includes the contribution of gluons in relativistic heavy ion collisions with the equilibrium and non-equilibrium quark-gluon plasma. We develop a new thermal jet-photon conversion mechanism which plays a vital role in the low transverse momentum region. The effect of the non-equilibrium quark-gluon plasma enhances the contribution of the thermal photons. The shadowing and iso-spin of the nucleus which can properly estimate the prompt photon production are also considered in our calculation.
基金Supported by the National Basic Research Program of China under Grant No 2004CB719800, and the National Natural Science Foundation of China under Grant Nos 60671002 and 60990322.
文摘We present a design for a polarization insensitive metamaterial absorber at 9.5 GHz by utilizing properly arranged resonant unit cells with orthogonal polarization sensitivity. Full-wave electromagnetic simulation demonstrates nearly perfect microwave absorption, which has been verified by experimental measurement with a maximum absorption of about 92% for incident wave with different polarizations. Furthermore, we find such a metamaterial thin absorber could work for a wide incident angle ranging from 0° to 50°with absorption no less than 80° for both the transverse electric mode and transverse magnetic mode.
基金Supported by the National Natural Science Foundation of China(No.81225025 and 91229201)
文摘Traditional Chinese medicine(TCM) holds a holistic theory, and specializes in balancing disordered human body using numerous natural products, particularly Chinese herbal formulae. TCM has certain treatment advantages for patients suffering from various complex diseases. However, due to the complex nature of TCM, it remains difficult to unveil such holistic medicine by the current reductionism research strategies, which treat both herbal ingredients and targets in isolation. Recently, an emerging network pharmacology approach has been introduced to tackle this bottleneck problem. A TCM-derived novel therapeutic concept, "network target", which is different from the Western medicine's "onetarget" concept, has been proposed from China. The network target strategy is able to illustrate the complex interactions among the biological systems, drugs, and complex diseases from a network perspective, and thus provides an innovative approach to access ancient remedies in a precision manner and at a systematic level, which also highlights TCM's potential in current medical systems.
文摘A low-cost photoconductive dual-band detector was prepared using a nanoporous ZnO film sensitized by PbS quantum dots (QDs). At room temperature the device shows a UV response in the wavelength range of 200-400 nm with a 370 nm peak responsivity of 4.0×105 V/W and a vis-NIR response from 500 to 1400 nm with a 700 nm peak responsivity of 5.4×105 V/W. By increasing the size of the PbS QD, the response can be extended up to 2.9 μm. It is suggested that the UV response is a result of interband absorption of UV radiation by ZnO and the IR response comes from the absorption of PbS QDs.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10604042 and 10674038, the National Basic Research Program of China under Grant Nos 2006CB302901 and 2007CB310408, the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality, and the Science and Technology Program of Beijing Educational Committee under Grant No KM200810028008.
文摘A method to measure the refractive index for high reflectance materials in the terahertz range with terahertz time domain reflection spectroscopy is proposed. In this method, the THz waveforms reflected by a silicon wafer and high reflectance sample are measured respectively. The refractive index of the silicon wafer, measured with the THz time domain transmission spectroscopy, is used as a reference in the THz time domain reflective spectroscopy. Therefore, the complex refractive index of the sample can be obtained by resorting to the known reflective index of the silicon and the Fresnel law. To improve the accuracy of the phase shift, the Kramers-Kronig transform is adopted. This method is also verified by the index of the silicon in THz reflection spectroscopy. The bulk metal plates have been taken as the sample, and the experimentally obtained metallic refractive indexes are compared with the simple Drude model.