In order to design and fabricate the flexible force sensor , we have researched the piezoresistivity of silicon rubber/ carbon black composites and given the academic calculation formula between pressure and electrical resistivity. The experiments illustrate that the homogenization of carbon black and the elastic modulus of composites can be improved effectively by dispersing nanosize silica filler and using organic solvent . As a result , the piezoresistivity of composites can be improved. Carbon black content of 10% with good pressure-sensitive conductive rubber, heat-sensitive in a certain pressure range is also good.Moreover , the fore - sensitive device fabricated by the composites is free from the limitation of the surface shape of the tested objects which can be widely applied to various squeeze stress measurement on any regular and unregular curve surfaces.
Through making questionnaire survey and on site investigation on skiing field in Tadong city,by using the method of literature review,interview and mathematical statistics,this paper finds out that Datong ski tourism industry is now found at an early stage of development,there are many areas is insufficient.Based on deficiencies in the development,some feasible measurements and reference are put forward in order to promote the skiing tourism industry in Datong city.
In future optical transport networks, light-path performance analysis is of great practical significance for fully automated management. In general, the quality of transmission (QoT) of lightpaths, measured by optical quality factor or optical signal-to-noise ratio, has a complex time-varying process, along with the interactions of the other lightpath state parameters (LSPs), such as transmit power, chromatic dispersion, polarization mode dispersion. Current studies are mostly focused on lightpath QoT estimation, but ignoring lightpath-level data analytics. In this case, our article proposes a novel lightpath performance analysis method considering recurrence plot (RP) and cross recurrence plot (CRP). Firstly, we give a detailed interpretation on the recurrence patterns of LSPs via a qualitative 2-D RP representation and its quantitative measure. It can potentially enable the accurate and fast lightpath failure detection with a low computational burden. On the other hand, CRP is devoted to modeling the relationships between lightpath QoT and LSPs, and the correlation degree is determined by a geometric mean of multiple indexes of cross recurrence quantification analysis. From the view of application, such CRP analysis can provide the effective knowledge sharing to guarantee more credible QoT prediction. Extensive experiments on a real-world optical network dataset have clearly demonstrated the effectiveness of our proposal.
VO2 film is expected to be used in smart radiation devices (SRD) due to changes in infrared reflection caused by semiconductor-to-metal transition (SMT). In this work, a tunable thermal emitter which consisted of Al layer, CaF2 layer and VO2 layer was designed to achieve variable emittance with temperature. The variation of dielectric parameters of VO2 shell caused by temperature change was used to regulate the absorption characteristics of the structure, to realize the positive emittance-switching performance of the thermal emitter device. It was found that the total emittance of the device could reversibly change from 0.03 at 30℃ to 0.72 at 90℃ with an emittance variability of 0.69 in 4-14 µm. In addition, the influence of the thickness of CaF2, VO2 layers and the intermediate layer material on the emittance variation of the device was studied. These results shown that the device has the best VO2 and CaF2 layer thicknesses of 20nm and 1000nm, respectively. Particularly, too high refractive index of the intermediate layer material will cause the device to produce multiple resonance peaks at high temperature, which will reduce the average emissivity of the entire band, resulting in a smaller change in the emissivity of the thermal emitter.
In this paper, radiation spectrum design methods of material were proposed. Effect of temperature and atmospheric transmission on the infrared radiation transmission of materials was studied. The radiation properties of different materials were analyzed at different temperature. The transmission of aircraft surface materials infrared radiation was studied, according to the environment and the radiation transmission. Moreover, the spectrum of the two materials with the consistent emissivity was studied. Material has less radiation characteristic peak within the 3.0−4.3 μm and low radiation intensity within the 8−14 μm, which has good spectral stealth properties at 250−450 K. The radiation spectrum peak of the material was not obvious within the 4.3−8.0 μm owing to the low transmittance of atmosphere. In conclusion, research results have good significance for the spectral stealth design of materials, and can potentially be used in infrared spectral stealth technology and equipment.
The Medipix All Resolution System (MARS) system is a commercial spectral/multi-energy micro-CT scanner designed and assembled by the MARS Bioimaging, Ltd. in New Zealand. This system utilizes the state-of-the-art Medipix photon-counting, energy-discriminating detector technology developed by a collaboration at European Organization for Nuclear Research (CERN). In this paper, we report our preliminary experimental results using this system, including geometrical alignment, photon energy characterization, protocol optimization, and spectral image reconstruction. We produced our scan datasets with a multi-material phantom, and then applied ordered subset-simultaneous algebraic reconstruction technique (OS-SART) to reconstruct images in different energy ranges and principal component analysis (PCA) to evaluate spectral deviation among the energy ranges.
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