- 标题
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- 实验方案
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[IEEE 2018 IEEE International Conference on Computer and Communication Engineering Technology (CCET) - Beijing, China (2018.8.18-2018.8.20)] 2018 IEEE International Conference on Computer and Communication Engineering Technology (CCET) - Elastic Optical Network Spectrum Fragmentation Algorithm
摘要： Aiming at spectrum allocation problem in elastic optical networks, a spectrum allocation method that combines the advantages of genetic algorithm and ant colony algorithm is proposed. This method uses genetic algorithm to generate the initial solution with rapid random population global search ability. Then the initial solution of the genetic algorithm is transformed into the initial distribution of pheromone required by the ant colony algorithm using the cohesion strategy. Finally, the positive feedback and efficient convergence of the ant colony algorithm are used. Features Find the optimal solution and provide a solution for improving network efficiency
关键词： Network Spectrum,Elastic Optical Network,Fragmentation Algorithm
更新于2025-09-23 15:23:52
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Length-Dependent Electronic Transport Properties of the ZnO Nanorod
摘要： The two-probe device of nanorod-coupled gold electrodes is constructed based on the triangular zinc oxide (ZnO) nanorod. The length-dependent electronic transport properties of the ZnO nanorod was studied by density functional theory (DFT) with the non-equilibrium Green’s function (NEGF). Our results show that the current of devices decreases with increasing length of the ZnO nanorod at the same bias voltage. Metal-like behavior for the short nanorod was observed under small bias voltage due to the interface state between gold and the ZnO nanorod. However, the influence of the interface on the device was negligible under the condition that the length of the ZnO nanorod increases. Moreover, the rectification behavior was observed for the longer ZnO nanorod, which was analyzed from the transmission spectra and molecular-projected self-consistent Hamiltonian (MPSH) states. Our results indicate that the ZnO nanorod would have potential applications in electronic-integrated devices.
关键词： current–voltage (I–V) curves,molecular-projected self-consistent Hamiltonian (MPSH),transport properties,zinc oxide (ZnO) nanorod,transmission spectrum
更新于2025-09-23 15:23:52
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CsxWO3 nanosheet-coated cotton fabric with multiple functions: UV/NIR shielding and full-spectrum-responsive self-cleaning
摘要： Utilizing fewer functional materials to achieve multifunctional fabrics via facile approaches have been confronting worldwide scientists with an enormous challenge. In this study, a novel multifunctional cotton fabric, combining UV/NIR shielding and full-spectrum-responsive self-cleaning, has been fabricated via self-assembly of CsxWO3 nanosheets based on electrostatic interaction assisted by Poly (diallyldimethylammonium chloride) (PDDA) in aqueous solution. The microstructure of CsxWO3 nanosheets and their self-assembly coating on cotton fabric were characterized and investigated. The functional properties of the CsxWO3-coated cotton fabric, including UV/NIR shielding and photocatalytic self-cleaning were evaluated. The results indicate that the CsxWO3-coated cotton fabric exhibits superb UV/NIR and heat shielding performance with 15.8 °C and 5.9 °C lower than no coverage and coverage by none-treated cotton fabric, respectively. Moreover, the well-coated cotton fabric demonstrates photocatalytic self-cleaning property responsive to the light ranging from UV, Vis to NIR, especially exhibits highly efficient self-cleaning under the respective irritation of full-spectrum, UV and Vis light (color faded completely within 10 h). In summary, the CsxWO3-coated fabrics can achieve multi-functions of UV shielding, heat insulation and self-cleaning by means of a single functional nanomaterial and promise of huge applications in functional textiles.
关键词： full-spectrum self-cleaning,self-assembly coating,UV/NIR shielding,CsxWO3 nanosheets,functional cotton fabric
更新于2025-09-23 15:23:52
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Open-path Halon 1301 NDIR sensor with temperature compensation
摘要： Halon 1301 (bromotrifluoromethane) is a kind of fire extinguishing agent in aviation industry. Volume concentration measurement of Halon 1301 is necessary in the design of aircraft fire protection systems. In this research, an open-path Halon 1301 non-dispersive infrared (NDIR) sensor has been developed for in-situ measurement, a novel cavity-type absorption module was designed to get fast response and more compact structure. Experiment results show that measurement was remarkably affected by temperature. Therefore, temperature compensation algorithm was also studied in this thesis, which was proven to be effective within the range of 25 oC-105 oC.
关键词： non-dispersive infrared (NDIR),mid-infrared absorption spectrum,Halon 1301,temperature compensation,concentration measurement
更新于2025-09-23 15:23:52
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Dehydrogenation-driven to synthesize high-performance Lu2Si4N6C:Ce3+- a broad green-emitting phosphor for full-spectrum?lighting
摘要： Green phosphor Lu2Si4N6C:Ce3+ (LSNC:Ce3+) shows an ideal feasibility to the near ultraviolet LED (n-UV LED) for “Full-Spectrum Lighting” (FSL). However, it is complex to synthesize pure Lu2Si4N6C phase. Herein, we prepared LSNC:Ce3+ via a novel dehydrogenation-driven high temperature solid-state reaction method, which distinctly optimized the morphology, and then significantly enhanced the photoluminescent performance of LSNC:Ce3+. The improving mechanism ascribed to the stepwise dehydrogenation of LuH3 which was beneficial to further shear LuH3 particles. The LSNC:Ce3+ phosphor obtained by the optimized process exhibits excellent thermal stability, and its external quantum efficiency is 57.3 %. Interestingly, the intensities of excitation peaks decrease at 375 nm while it increases at 425 nm gradually with the Ce3+ concentration. It is reasonably ascribed to the different ability of photo-ionization in different 5d levels. Finally, the constructed w-LED with the titled phosphor exhibits a well-distributed warm white light with high color rendering index (Ra = 96.6, R9 = 96, R12 = 82). It indicates that the LSNC:Ce3+ gives assistance to compensation for the “spectrum chasm” in blue-green region, as well as contributes to the improvement of Ra and R9, that is beneficial for full-spectrum lighting.
关键词： Carbonitride,n-UV LED,Reaction mechanism,Full-Spectrum,Green phosphor Lu2Si4N6C:Ce3+
更新于2025-09-23 15:23:52
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Wide Spectrum Photocatalytic Activity in Lanthanide-doped Upconversion Nanophosphors Coated with Porous TiO2 and Ag-Cu Bimetallic Nanoparticles
摘要： Approaches towards maximum utilization of solar light spectrum for photocatalysis have currently attracted great interest. The combination of profoundly different properties, such as, upconversion, semiconducting and plasmonic properties can produce a favorable path in efficient utilization of the different regions of solar light reaching to earth. In this regard, design and fabrication of microstructures consisting of upconverting lanthanide doped nanophosphors coated with porous semiconducting material, TiO2 and decorated with plasmonic Ag-Cu bimetallic nanoparticles is presented in this work. These microstructures display great stability and exceptional photocatalytic activity by absorbing wide spectrum from ultraviolet to near infrared. The photocatalytic activity could be attributed to the synergistic effects between the different components and the efficient energy transfer between them. The development of such sort of hybrid microstructures could pave way for the development of new materials for the efficient utilization of the wide spectrum of sunlight.
关键词： bimetallic plasmonic nanoparticles,titania,wide spectrum utilization,photocatalysis,Upconversion nanophosphors
更新于2025-09-23 15:23:52
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Structural, optical, electrical and thermal characteristics of La{CS(NH2)2CO(NH2)2}Cl3 : A novel hybrid complex for optoelectronic applications
摘要： A hybrid complex of lanthanum chloride with urea and thiourea is crystallized at room temperature by conventional solution method. The structural investigations by single crystal X-ray diffraction confirmed the orthorhombic system with cell dimensions a = 7.676 ?, b = 8.564 ?, c = 5.498 ?, α = β = γ = 90°. The optical studies by UV–VIS absorption spectroscopy shows the complex exhibits transmittance about 96%. The complex is characterized as the wide band gap crystals with value greater than 4 eV. The dielectric properties were studied in frequency range 10 kHz–1 MHz in temperature range 303–453 K. The ac conductivity was found to obey the universal power law and suggests the correlated barrier hoping mechanism dominating the conduction process. The thermal stability and the decomposition mechanism were confirmed by thermo gravimetric and differential thermo analytical (TG/DTA) techniques.
关键词： Dielectric analysis,ac conductivity,Hybrid complex,X-ray diffraction,UV–Vis spectrum
更新于2025-09-23 15:23:52
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Study on Band-Gap Behaviors of 2D Hierarchical Re-Entrant Lattice Structures
摘要： An investigation of Poisson’s ratios and band gap behaviors of 2D hierarchical re-entrant lattice structures is conducted using finite element method (FEM). The structure with a hierarchy order n (n≥1) is constructed by replacing each outmost vertex of the re-entrant octagons of a hierarchical structure of hierarchy order n?1 with a smaller self-similar re-entrant octagon. The dispersion relation and transmission spectrum of the proposed hierarchical structures are analyzed based on the Bloch’s theorem. The effects of geometrical parameters, order of rotational symmetry and orientation angle of some types of re-entrant polygon cores on the lattice Poisson’s ratio and band gap structures are also investigated. Results show that the re-entrant structures with first order hierarchy exhibit a wider band gap and a stronger attenuation effect compared with structures without structural hierarchy. The first order 2D hierarchical re-entrant structure with a negative Poisson’s ratio of ?0.032 exhibits the widest band gap, 17.8% wider than that of the zeroth order 2D re-entrant structure. The order of rotational symmetry and the orientation angle of the re-entrant polygon cores of the lattice have a strong impact on the lattice Poisson’s ratio and band structures.
关键词： re-entrant,negative Poisson’s ratio,band gap,hierarchical structure,transmission spectrum
更新于2025-09-23 15:23:52
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Stability and Spectral Properties of General Tree-Shaped Wave Networks with Variable Coefficients
摘要： The stability of general tree-shaped wave networks with variable coefficients under boundary feedback controls is considered. Making full use of the tree-shaped structures, we present a detailed asymptotic spectral analysis of the networks. By proposing the from-root-to-leaf calculating technique, we deduce an explicit recursive expression for the asymptotic characteristic equation and the spectral properties are further obtained. We show that the spectrum-determined-growth (SDG) condition holds. Thus the stability analysis of the closed-loop system can be completely converted to the infimum estimation of the asymptotic characteristic equation. Especially, we further show that the infimum is positive so as to obtain the exponential stability by estimating the recursive expression in from-leaf-to-root order. Some numerical simulations are presented to illustrate and support the theoretical results.
关键词： Exponential stability,Variable coefficient,Spectrum-determined-growth (SDG) condition,Recursive characteristic equation,Feedback control,Wave network
更新于2025-09-23 15:23:52
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Study on sliding-window length based on Rayleigh backscattering spectrum correlation in distributed optical-fiber strain measurement
摘要： A theoretical model is established for estimating the strain measurement error based on the Rayleigh backscattering spectrum correlation in distributed optical fiber strain measurements. Assuming the signal is much larger than the noise, the theoretical model predicts the strain measurement error using noise variance and the defined quality factor Q of the Rayleigh backscattering spectrum. Furthermore, an algorithm based on the quality factor Q is proposed to select an optimized sliding-window. The sliding-window length can be obtained by calculating the threshold value of the quality factor using a theoretical model corresponding to the required strain measurement accuracy. Compared with the traditional method where the sliding-window length is defined by the user based on spatial resolution requirements or an empirical definition, the sliding-window length determined by the algorithm is more reasonable and can be automatically defined, alleviating the requirement for user inputs. To verify the correctness of the theoretical model, two experiments are set up: a self-correlation experiment, that analyzes the effect of the quality factor on the strain measurement accuracy, and a virtual experiment of the noise influence, which analyzes the effect of different noise variances. The experimental results are in good agreement with those of the model.
关键词： Distributed optical fiber strain measurement,Rayleigh backscattering spectrum correlation,Optical frequency domain reflectometer
更新于2025-09-23 15:23:52