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In this article, a graphene‐based reflective metasurface which can generate Bessel beams at arbitrary directions is proposed at 1.52 THz. It chooses the classical cross structure as the unit cell and extends the coverage of the reflection phase to 360° by adjusting two key parameters while maintaining a relatively high‐reflection amplitude. Combined with the excellent impedance characteristics of graphene in the terahertz regime and the long energy transmission distance of the nondiffraction beam, the reflective metasurface finally realize the pseudo‐Bessel beam with a maximum propagation distance of about 3358.85 um and a deflection of about 15° in yoz‐plane as expected. Two forms of efficiency are proposed for the metasurface, one is the focusing efficiency, the other is the conventional radiation efficiency. The simulation results show that the former shows a trend of increasing first and then decreasing, which conforms to the beam‐forming property of Bessel beam; the latter can be basically maintained at high value of 70% within the nondiffraction propagation distance, which conforms to the energy transmission characteristic of the nondiffraction beam. All the studies show that the graphene‐based metasurface combined with the nondiffraction theory has the advantages of highly controllable beam deflection, long focusing distance, and high‐energy transfer efficiency in the terahertz regime, so it will have a broad application prospect in terahertz telecommunication, wireless energy transmission, near‐field detecting, imaging and many other fields. [ABSTRACT FROM AUTHOR]

Abstract: A novel wideband power divider with ultra‐wideband suppression of harmonics is proposed in this paper. The power divider is composed of double‐sided parallel spoof surface plasmon polaritons transmission line (DSP‐SSPP‐TL) with periodical grooved bow‐tie cells. The cut‐off frequency of DSP‐SSPP‐TL can be flexibly adjusted by changing the parameters of bow‐tie cells. To demonstrate that, dispersion relations of the bow‐tie cells with different parameters are simulated, and three DSP‐SSPP‐TL counterparts are experimented. Then, a power divider centered at 3.31 GHz (f0) is designed, fabricated, and measured. Experimental results indicate that the 10‐dB return loss bandwidth of the proposed power divider is about 146% from 0.9 to 5.73 GHz, and the upper stopband is extended up to 40 GHz (12.1 f0) with the suppression level above 32 dB. Moreover, ultra‐wideband isolation between two output ports of the proposed power divider could be achieved by employing two lumped resistors between two DSP‐SSPP‐TLs. [ABSTRACT FROM AUTHOR]

A compact broadband sequential feeding network designed for a wideband circular antenna is simulated and fabricated, where the 50-Ω input is equally divided into four 50-Ω outputs with equal amplitude and 90° successive shifts. This series-type feed network just composes of two double-sided couplers which have been further reduced to a great degree by meandering the microstrips. The measured 10-dB impedance bandwidth is 39% from 1.71 to 2.54 GHz, and the phase difference between two arbitrary adjacent ports is 90° ± 4.7° over the 1.75-2.35 GHz range. Note that the measurements agree reasonably well with the simulations. [ABSTRACT FROM AUTHOR]

In this paper, a circularly polarized filtering antenna with high out-of-band radiation rejection level is proposed. The entire design consists of a patch and a filtering feeding network, which are connected by metallic pins. First, a high-selectivity filtering power divider is constructed utilizing two shunted bandpass filter. Next, a 90° phase difference could be realized by adjusting the length of the two outputs of the power divider. The measured transmission coefficient of the feeding network is 6.3 dB at 2 GHz. The measured axial ratio is below 3 dB within the operating band of the proposed antenna, which represents the effectiveness of the proposed feeding network. In addition, the obvious radiation nulls can be found from the antenna measurement because of the transmission zeros introducing by the filtering power divider. The measured gain is 5.73 dB at 2 GHz and decreases dramatically in stopband. Specially, the measured gain is −30 and −41 dB at 1.95 and 2.06 GHz. The proposed antenna has an excellent filtering characteristic compared with those without the filtering feeding network. To sum up, the proposed antenna and filtering power divider are promising in the modern wireless communication systems. [ABSTRACT FROM AUTHOR]

Objective: To observe the feasibility of roleplay simulation in improving the quality management of nursing services., Method: In this retrospective study, 80 nursing staff were enrolled as the study subjects from January 2019 to December 2020. They were divided into a study group (n=40, trained in roleplay simulation) and a control group (n=40, trained in conventional nursing skills) according to different training methods. The self-efficacy and quality of nursing services of the staff in the two groups were assessed retrospectively. Spearman's correlation analysis was conducted to analyze the relationship between the self-efficacy score and nursing service., Results: After training, the self-efficacy scores of the nursing staff in the study group were higher than those in the control group ( P <0.05). After training, the nursing staff in the study group had significantly higher service quality scores than those in the control group ( P <0.05). Spearman's analysis showed that the self-efficacy scores were positively correlated with the quality of nursing scores ( r =0.7091, P <0.0001). After training, the scores of the condition assessment of the nursing staff in the study group was higher than those in the control group ( P <0.05)., Conclusion: Roleplay simulation for nursing staff is helpful to improve the quality of nursing and the ability to deal with emergencies. This can be related to the improvement of self-efficacy in nursing staffs., Competing Interests: None., (AJTR Copyright © 2022.)