The thread-based ultra-high frequency radio frequency identification (UHF RFID) tag with a normal mode helix dipole antenna (NMHDA) shows great potential in anti-theft and implant wireless sensors; for the engineered and digitized design of the high-performance tag, it is necessary to know the physical relationship between the resonant frequency and structure parameters of the NMHDA. Previous work for the design of the NMHDA structure is based on the self-resonant principle, that is, zero port reactance, while the port impedance of the NMHDA in the UHF RFID tag thread at resonant frequency is ideally conjugate matching to the chip. Under the requirement of conjugate matching, this study built the physical relationship between the resonant frequency and structural parameters of the NMHDA (helical radius, helical pitch, and single arm length) by linking the chip impedance with the NMHDA impedance. Meanwhile, the reported equivalent impedance model of the NMHDA, consisted of a lumped inductor and a linear dipole antenna, was utilized and modified by considering the distributed capacitance deviation from the NMHDA geometry simplification as part of the lumped inductor. Finally, the physical relationship was put into practice for the design of an UHF RFID tag thread with expected resonant frequency, and the long reading range of the prototype (over 14 m) demonstrated the rationality of the modification. In addition, the discussion on the structure parameter of the NMHDA clarified the efficiency of our proposed method. Generally, the built physical relationship explicitly gives the physical effects of the structural parameters and provides a parametric method for the structure design of a NMHDA for the UHF RFID tag thread.
Biofuel is considered to be an important alternative energy in the future transportation. Its development is supported by the rest of the world. However, biofuel industry development is still very slow. From the previous research it is known that the supply chain coordination and other problems need to be solved to promote the supply chain ability. This paper studies biodiesel supply chain coordination problem from the view of disturbance management. It gives a disturbed coordination strategy which contains the optimal order quantity and the contract parameters. This paper has then verified the disturbed coordination strategy through using the actual data of Jiangsu Yueda Kate New Energy Co. Ltd. The result shows that when the market demand and the recovery cost are simultaneously disturbed, the coordination can make the biodiesel supply chain robust and the new strategy under the revenue sharing contract is better than the original one.
This paper describes the design of a novel ultrahigh frequency radio frequency identification (UHF RFID) tag thread that mainly consisted of the common yarn and the normal mode helix dipole antenna. The linear dipole antenna for the UHF RFID tag thread was too long to miniaturize the tag. In order to maximize the read performance and miniaturize the size of the tag, the basic antenna structure parameters, such as the helical pitch and single arm length, were optimized by analyzing the radiation parameter S11 of the normal mode helix dipole antenna based on simulation experiments. The simulation experiments started with optimizing the single arm length to obtain the minimum of the S11 parameter at resonant frequency, then the helical pitch was further optimized to limit the resonant frequency to the UHF range. The simulation results showed the resonant frequency rises with an increase of helical pitch and declines with an increase of single arm length. Furthermore, a series of UHF RFID tag threads with good performance from the simulation cases were prepared, and the performance of the optimized tag was validated. Generally, the UHF RFID tag thread with optimized helix dipole antenna could reduce the axial length of the tag by 57% and improve the reading range by 500%, and its performance was greatly superior to that of the UHF RFID tag thread with the classical linear dipole antenna.
A balanced parameter was proposed to design the high entropy alloys (HEAs), which defined by average melting temperature Tm times entropy of mixing ΔSm over enthalpy of mixing ΔHm, Ω=TmΔSm/ΔHm, if Ω is larger than 1.1, we can predict that the entropy is high enough to overcome the enthalpy, and solid solution is likely to form rather than the intermetallic ordered phases. The composition can be further refined by using high-throughput screening by preparing the compositional gradient films. Multiple targets co-sputtering is usually used to prepare the films, and physical masking can separate the samples independently, chemical masking can also applied if possible. One example is the self-sharpening screening by using nanoindentations, the serration behaviors may related to the self-sharpening compositions.
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