- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Helly hypergraph based matching framework using deterministic sampling techniques for spatially improved point feature based image matching
摘要： Hypergraphs are tools for matching of point-features incorporating spatial relationships in the form of hyperedges exhibiting topological and geometric features between the points of images to be matched. Considering all possible hyperedges is computationally expensive and are randomly chosen in the state of the art techniques. A Helly Hypergraph based Matching Framework (HHMF) is proposed for the matching of images using point-features with effective hyperedges. The framework includes proposed algorithms such as Construction of Hyperedges using Point-features by Random (CHPR), Combinatorial (CHPC), and Exhaustive (CHPE) sampling techniques with and without Helly selection. The resultant hyperedges are treated with Adaptive Block Co-ordinate Ascent Graph Matching with Integer Projected Fixed Point algorithm. The performance of the proposed framework is evaluated in terms of Accuracy, Matching score, Execution time and Tensor Size for synthetic point sets and Willow wine image dataset. Based on the experimental studies carried out against existing framework, CHPC, and CHPE with Helly selection, exhibited better performance with 73.88% & 81% accuracy for 53.64 & 14.8% reduced tensor size respectively, in deformation noise tests, and 98% & 96% accuracy for 97% & 70% reduced tensor size in outlier tests. In the implicit experimental comparisons within sampling techniques, CHPR, and CHPE provided better performance with 81.37%, and 76% accuracy. In general, HHMF framework has reduced the tensor size and execution time for deterministic sampling cases during point sets matching. The framework can be extended in the near future by incorporating learning schemes for automated hypergraph based point sets matching.
关键词： Image matching,Hypergraph matching,Point correspondence,Helly property
更新于2025-09-23 15:21:01
-
Nd-Cr co-doped BiFeO3 thin films for photovoltaic devices with enhanced photovoltaic performance
摘要： BiFeO3 films and Nd-Cr co-doped BiFeO3 films were prepared by sol-gel method followed by spinning process on fluorine-doped tin oxide glass substrates. By testing the ultraviolet-visible absorption spectra, it was found that Nd-Cr co-doping will increase the light absorption rate of the film and reduce the optical band gap. The reduced bandgap can facilitate the transport of carriers. After Nd-Cr co-doping, the leakage current of the film is effectively reduced, which is near four orders of magnitude lower than the leakage current density of the pristine BiFeO3 film. The reduction of leakage current will enhance the ferroelectric polarization. The enhancement of ferroelectric polarization is more favorable for the separation of photogenerated carriers. Compared with the pristine BiFeO3 film, the short circuit photocurrent density, open circuit photovoltage and power conversion efficiency of Nd-Cr co-doped BiFeO3 film are all clearly improved. The Nd-Cr co-doped BiFeO3 films exhibited largely enhanced photovoltaic property, which favored the practical application of BiFeO3-based films in photovoltaic devices.
关键词： Element doping,Thin films,Ferroelectric property,Photovoltaic property,Bismuth ferrite,Leakage current
更新于2025-09-23 15:19:57
-
Wet Chemical Synthesis of Entangled Nano-fibrous Conducting Polyaniline (PANI) Mesh: Effect of Heating and Stirring
摘要： An effect of heating and stirring in a facile wet chemical route to synthesize entangled nano-fibrous mesh of doped polyaniline (PANI) was reported. The structural, morphological, and optical properties of PANI nano-fibers were found to be dependent on synthesis temperature and stirring. The XRD analysis confirms nano PANI formation with 2θ peaks around 15°, 21°, and 25° for (011), (020), and (200) crystal planes, respectively. The average crystallite size varies between 25 nm to 60 nm due to change in synthesis conditions. The SEM analysis reveals the clustered granule formation for PANI sample synthesized at 28 and 60 ℃ under continuous stirring, whereas, unstirred synthesis at 60 ℃ shows entangled nano-fibrous mesh morphology. The TGA study shows better thermal stability for PANI mesh over granular PANI. The FTIR spectra validates the emeraldine salt PANI formation with peaks corresponding to C-H, C-N, N=Q=N, N=B=N, and N-H vibration bands. The UV-Vis analysis shows the major absorbance peaks around λ: 340 nm (π- π* transition of benzenoid ring), and λ: 800 nm (π- π*, polaron-π* transitions). The dense entangled nano-fibrous coating of PANI synthesized at 60 ℃ without stirring shows highest electrical conductivity of 3.79 S·cm-1.
关键词： polyaniline,optical property,nano-fibrous mesh,electrical conductivity
更新于2025-09-23 15:19:57
-
Down-Shifting and Anti-Reflection Effect of CsPbBr3 Quantum Dots/Multicrystalline Silicon Hybrid Structures for Enhanced Photovoltaic Properties
摘要： Over the past couple of decades, extensive research has been conducted on silicon (Si) based solar cells, whose power conversion e?ciency (PCE) still has limitations because of a mismatched solar spectrum. Recently, a down-shifting e?ect has provided a new way to improve cell performances by converting ultraviolet (UV) photons to visible light. In this work, caesium lead bromide perovskite quantum dots (CsPbBr3 QDs) are synthesized with a uniform size of 10 nm. Exhibiting strong absorption of near UV light and intense photoluminescence (PL) peak at 515 nm, CsPbBr3 QDs show a potential application of the down-shifting e?ect. CsPbBr3 QDs/multicrystalline silicon (mc-Si) hybrid structured solar cells are fabricated and systematically studied. Compared with mc-Si solar cells, CsPbBr3 QDs/mc-Si solar cells have obvious improvement in external quantum e?ciency (EQE) within the wavelength ranges of both 300 to 500 nm and 700 to 1100 nm, which can be attributed to the down-shifting e?ect and the anti-re?ection property of CsPbBr3 QDs through the formation of CsPbBr3 QDs/mc-Si structures. Furthermore, a detailed discussion of contact resistance and interface defects is provided. As a result, the coated CsPbBr3 QDs are optimized to be two layers and the solar cell exhibits a highest PCE of 14.52%.
关键词： down-shifting e?ect,solar cell,anti-re?ection property,caesium lead bromide perovskite quantum dots (CsPbBr3 QDs),multicrystalline Si (mc-Si)
更新于2025-09-23 15:19:57
-
Effects of external magnetic field on the micro-structure of diamond-like carbon film prepared by pulsed laser deposition
摘要： The DLC ?lm was deposited by pulsed laser deposition in an external magnetic ?eld, and its optical property, surface morphology and atomic bonds were researched. The simulated ?ight tracks of the carbon ions in the magnetic ?eld showed that a number of the carbon ions were constrained by the Lorentz force, ?ing onto the substrate and forming the DLC ?lm. The contrast between the micro-structures of the DLC ?lms deposited in or out the magnetic ?eld showed that the external magnetic ?eld changed the expansion of the laser-produced plume and con?ned the surface diffusion of the charged particles on the substrate, improving the content of the sp3 bonds in the DLC ?lm.
关键词： pulsed laser deposition,diamond-like carbon ?lm,external magnetic ?eld,optical property,atomic bond
更新于2025-09-23 15:19:57
-
Direct printing of performance tunable strain sensor via nanoparticle laser patterning process
摘要： Flexible electronics are attractive because of flexibility and portability. The circuits are printed on flexible substrates, which are delicate and heat-sensitive. Traditional photolithography, which uses high temperatures and corrosive chemicals, easily causes damages in flexible substrates. Here, we develop a low-cost nanoparticle based laser patterning process for fabrication of flexible electronics. Nanoparticles are sintered using a low-power laser as they are selectively deposited. Copper and silver particles were successfully deposited on paper and polyethylene terephthalate substrates. The effects of process parameters on deposition performance were studied to understand the process-structure–property relationship. The thermal effects of the laser on film morphology were observed. The sensitivities of the electrical properties with respect to the porosities at different laser power densities were analysed. With different laser energy levels, the process allows for selective deposition, properties control of printed patterns, and flexible substrate cutting. The fabrications of strain sensor and kirigami electronics were demonstrated.
关键词： strain sensor,electrical properties,hybrid manufacturing,Nanoparticle deposition,flexible electronics,process-structure–property relationship
更新于2025-09-23 15:19:57
-
Composite electrode of TiO2 particles with three kinds of crystal phases for significantly improved performance of dye-sensitized solar cells
摘要： A novel composite electrode of TiO2 particles with three kinds of crystal phases is fabricated for improving the dye-sensitized solar cell's performance. The photoelectric conversion efficiency of solar cell with the content of 30 wt% brookite nanocubes and 70 wt% P25 could reach 7.40%. It is obvious that brookite nanocubes are advantageous in terms of reduced charge recombination and higher voltage. On the other hand, P25 gives advantages of high surface area for dye loading and higher charge collection efficiency. This work shows a new photoelectrode design for enhanced energy conversion of DSSCs.
关键词： Composite electrode,Dye-sensitized solar cell,Brookite titania,Photoelectrochemcial property,Photovoltaic conversion efficiency
更新于2025-09-23 15:19:57
-
Luminescence properties of novel red-emitting phosphors Ba3B6Si2O16: Eu3+ for near-UV excited LED
摘要： A novel Eu3+ doped Ba3B6Si2O16 red-emitting phosphor was synthesized by a high temperature solid state reaction and its luminescence properties were investigated. All the phosphors are pure phase of triclinic Ba3B6Si2O16 in structure. Under 393 nm excitation, Ba3B6Si2O16: Eu3+ phosphor exhibits intense red emissions due to the characteristic f–f transitions of Eu3+ with the strongest emission peaks at 613 nm. The optimum doping concentration of Eu3+ is 0.09 and the corresponding critical distance is estimated to be 23.9 ?. The emission intensity decreases with increase of Eu3+ ion concentration(x>0.09) due to dipole-dipole interactions among Eu3+. Ba3B6Si2O16: Eu3+ phosphor exhibits high color purity (92%), good thermal stability (the activation energy of 0.2121 eV) and high quantum efficiency (36.5 %) with CIE chromaticity coordinates of (0.6460, 0.3534). These results indicate that Ba3B6Si2O16: Eu3+ phosphor can be anticipated as a red emitting phosphor for near-UV pumped white LEDs.
关键词： luminescence property,Eu3+ ions,phosphors
更新于2025-09-23 15:19:57
-
Employing a Narrow-bandgap Mediator in Ternary Solar Cells for Enhanced Photovoltaic Performance
摘要： Ternary organic solar cells (OSCs) provide a convenient and effective means to further improve the power conversion efficiency (PCE) of binary ones via composition control. However, the role of the third component remains to be explored in specific binary systems. Herein, we report ternary blend solar cells by adding the narrow-bandgap donor PCE10 as the mediator into the PBDB-T:IDTT-T binary blend system. The extended absorption, efficient fluorescence resonance energy transfer, enhanced charge dissociation and induced tighter molecular packing of the ternary blend films enhance the photovoltaic properties of devices and deliver a champion PCE of 10.73% with an impressively high open-circuit voltage (VOC) of 1.03 V. Good miscibility and similar molecular packing behavior of the components guarantee the desired morphology in the ternary blend films, leading to solar cell devices with over 10% PCEs at a range of compositions. Our results suggest ternary systems with properly aligned energy levels and overlapping absorption amongst the components hold great promises to further enhance performance of corresponding binary ones.
关键词： ternary solar cell,energy transfer,induced crystallization property,non-fullerene acceptors,molecular mediator
更新于2025-09-23 15:19:57
-
Plasmonic responses of Cua??Ag bimetallic system: Influence of distinctiveness and arrangements
摘要： In this article, the effect of the distinctiveness and arrangements on the plasmonic resonance of Cu–Ag system were studied by finite element method, and the effect of morphologies on the plasmonic properties of Cu@Ag core@shell NPs and Cu–Ag corn-cob liked NPs was investigated by experiment. For Cu@Ag core-shell structure, as the fixed thickness of Ag-shell at 10 nm, the dipole plasmon resonance gradually blue-shifts with increasing the radius of Cu core, and as the fixed radius of Cu-core at 50 nm, the feature peak shows a red-shift and broadening with increasing the thickness of Ag shell. For Cu–Ag corn-cob structure, the feature for different Ag coverage are similar to each other and most of the them follow the blue-shifted tendency with the increase the degree of Ag-coverage. Furthermore, as the regular-shaped structure increases (form trigonal to spherical), the plasmon resonance gradually blue shifts, and finally, we use two parameters to describe the different idealized Cu–Ag structure: separation, exterior contact, intersection and core@shell. The combined information from our simulation and experiment will give guidelines for choosing adequate particles when aiming at certain plasmonic properties.
关键词： Finite element method,Structure-property,Core-shell,Cu–Ag corn-cob-liked,Plasmonic absorption
更新于2025-09-23 15:19:57