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The continuous increase in communication capacity is accompanied by an increase in transmission frequency, which creates new demands on the transmission efficiency in modern. Signal relay transmission can increase the transmission distance, however, conventional repeaters relay the signal in a specified direction, which is difficult to accommodate communication when a receiving device suddenly appears around the repeater. In this work, we propose a new signal transmission repeater, which is implemented by an adaptively reconfigurable multi-beam reflective metasurface based on multispectral detection. The reconfigurable metasurface with varactor diodes is designed and the mapping of phase profiles to voltages is established by polynomial fitting method. Visual, laser, infrared and ultrasonic detectors are used to detect targets in different scenarios. Thus, the detection information is fed back to the reconfigurable metasurface for adaptively multi-beam switching. As verification, the adaptive metasurface repeater was fabricated and measured to verify our design. All the results exhibit consistency with theoretical design. Importantly, this work paves a new way to intelligent metasurfaces and may find applications in intelligent communications, smart home, etc.

Geometric phases are very important for achieving broadband functional metasurfaces, which are usually obtained by rotating meta‐atoms. However, such rotation‐induced geometric phases are inherently spin‐coupled, with the same magnitude and opposite sign for left‐ and right‐handed circularly polarized (LCP and RCP) waves, which is unfavorable for designing different functions for LCP and RCP waves. Therefore, it is desirable that geometric phases for single circular polarization be explored. In this work, it is first proposed to achieve geometric phases for single polarization by delicately designing curvature of the meta‐atom, which only imparts geometric phase to RCP or LCP waves. Then, spin‐decoupled metasurfaces are designed by hybridizing such curvature‐induced geometric phases and conventional rotation‐induced geometric phases. Two prototypes of dual‐channel functional metasurfaces are designed, fabricated, and measured. Both the simulated and experimental results verify the spin‐decoupled phase modulation. This work expands the methods of phase engineering in metasurfaces and may find wide applications in communication, sensing, imaging, and others. [ABSTRACT FROM AUTHOR]

All-angle wideband electromagnetic (EM) transparency for dual polarizations is desired for many practical applications. Conventionally, surface-mount anti-reflection materials or films are usually used to reduce the reflection and thus enhance transparency. In this paper, we propose to achieve wideband EM transparency under extreme angles for both TE- and TM-polarizations using embedded anti-reflection metasurface. The metasurface is composed of a pair of long and short metallic strips, which can introduce both plasma and lattice modes into the original half-wave wall. The plasma mode can create an angle-stable transmission peak at a lower frequency while the lattice mode renders a transmission peak under extreme angles at a higher frequency due to scattering cancellation between short strips and the substrate. By synergizing the plasma, half-wave, and lattice modes consecutively, wide-band transparency can be achieved under extreme angles for TE polarization. Due to the anisotropy of the metasurface, wideband transparency under TM-polarization is maintained. This finally enables us to obtain wideband EM transparency for dual polarizations under extreme angles. More importantly, the metasurface can also be customized to operate best under any given incident angle. Prototypes were designed, fabricated, and measured. Both the simulation and experiment results verify our method. This work provides an efficient route to wideband EM transparency under extreme angles and may find wide applications in communication, radar, and others. [ABSTRACT FROM AUTHOR]

The traditional demand split logistics distribution schemes are mainly based on vehicle distribution. In recent years, with the rapid development of civil UAVs, the use of UAVs for distribution will be more efficient and economical in some specific conditions. In this paper, through the analysis of the advantages of UAV distribution, we simulate the demands and distribution schemes in real scene, especially in remote mountainous areas. And then, we propose to define a demand-splitting distribution scheme of vehicle-supported UAV, which ensures the customer point will be satisfy demand when the loading capacity of the UAV is exceeded. This scheme aims to provides a realizable distribution scheme for the customers point in mountainous areas with large demand.

Metasurfaces composed of subwavelength structure arrays provide a diverse and powerful platform for generation of complicated electromagnetic (EM) fields and wavefronts manipulation and have triggered an unprecedented research upsurge in electromagnetism with the development of computer‐generated holography (CGH). Different from conventional scalar holograms only containing amplitude and phase properties, a vectorial hologram that benefits from the maneuverability of polarization of EM fields exhibits more immeasurable application potential and is simultaneously regarded as an urgent requirement. In this work, assisted by single completely spin‐decoupled meta‐particles, which perfectly combine the functions of simultaneous and independent amplitude and phase modulation of orthogonal polarization states containing left‐ and right‐handed circularly polarized (LCP&RCP) components, a vectorial hologram induced through eigenstates degeneracy with the ability of encoding arbitrary polarization is proposed in the microwave region. As the proof of concept, eight distinct holograms with specified polarizations and six‐channel polarization‐multiplexed hologram display are fabricated and characterized, further showcaing the versatility of the approach for the customization of arbitraty polarization and integration of reconstructed patterns. With the advantages of multi‐controllability and ultra‐compactness, the constructed monolayer completely spin‐decoupled paradigm for vectorial regulation may find prospective application aspects in spin detection, target perception, multi‐channel data encryption, and many other related fields. [ABSTRACT FROM AUTHOR]

The back-scattering from front edge diffraction contributes significantly to mono-static radar cross section under TE-polarization when the specular reflection of an object is eliminated by elaborate shaping. With the aim to suppress the back-scattering of thin metallic edge, we propose to achieve wideband radar cross section (RCS) reduction by integrating an absorbing structure (AS) in front of the edge. The unit cell of AS is composed of a longitudinal array of metallic strips with linearly decreasing lengths. Under TE-polarized illumination, spoof surface plasmon polariton (SSPP) can be excited with high efficiency. Due to the deep-subwavelength property of SSPP, electromagnetic waves are highly confined around the AS, leading to strong local field enhancement and hence to wideband absorption. In this way, back-scattering of the edge is suppressed and the mono-static RCS can be reduced significantly over wide band. To verify this method, we designed, fabricated and measured a prototype. The results of both simulation and measurement indicate that our proposal can significantly suppress edge scattering, whose RCS reduction more than 10 dB achieves at range of 8.8–17.8 GHz under TE polarization. This work provides a new alternative of suppressing edge diffraction and may find applications in electromagnetic compatibility, radar stealth, etc.

Controlling objects with body language is an extremely interesting ability for human beings. Recognizing different gestures is an effective way to collect valuable information, which is used to switch the radiation characteristic of beam scanning antennas. However, most existing beam scanning antennas are wire-connected and manually controlled by users. Thereby, a novel framework of gesture-controlled antennas is proposed in this paper. Rather than DC voltages supplied by powers or AC voltages supplied by signal generators, the beam scanning antenna can be effectively controlled by different gesture commands collected in real time from the user. On this basis, considering the advantages of the low cost and wide frequency band of liquid crystal (LC) materials, a LC-based fixed-frequency beam scanning leaky wave antenna (LWA) with gesture-controlled systems is demonstrated as one example. Different gestures can be recognised as controlled information to supply corresponding output signals by field programmable gate arrays (FPGAs) for the LC-based LWA. Based on the proposed framework, a verification system is tested, which demonstrates that the radiation characteristic can be effectively controlled by the user's gesture. This work supplies a novel way for intelligent beam scanning antennas with potential applications in the internet of things (IoT), satellite and 5 G/6 G communications. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to present the clinical characteristics and dynamic changes in laboratory parameters of the coronavirus disease 2019 (COVID-19) in Guangzhou, and explore the probable early warning indicators of disease progression. Method: We enrolled all the patients diagnosed with COVID-19 in the Guangzhou No. 8 People's Hospital. The patients' demographic and epidemiologic data were collected, including chief complaints, lab results, and imaging examination findings. Results: The characteristics of the patients in Guangzhou are different from those in Wuhan. The patients were younger in age, predominately female, and their condition was not commonly combined with other diseases. A total of 75% of patients suffered fever on admission, followed by cough occurring in 62% patients. Comparing the mild/normal and severe/critical patients, being male, of older age, combined with hypertension, abnormal blood routine test results, raised creatine kinase, glutamic oxaloacetic transaminase, lactate dehydrogenase, C-reactive protein, procalcitonin, D-dimer, fibrinogen, activated partial thromboplastin time, and positive proteinuria were early warning indicators of severe disease. Conclusion: The patients outside epidemic areas showed different characteristics from those in Wuhan. The abnormal laboratory parameters were markedly changed 4 weeks after admission, and also were different between the mild and severe patients. More evidence is needed to confirm highly specific and sensitive potential early warning indicators of severe disease. [ABSTRACT FROM AUTHOR]

In this article, we propose a method of achieving broadband decoupling between large antenna arrays using magnetic metasurface (MM). To realize broadband isolation performance, the MM consists of four sub‐regions composed periodic arrays of split‐ring resonators (SRRs). The four sub‐regions can achieve negative permeability in sequential frequency ranges, which can together cover the whole X‐band by proper combinations. When the MM is placed between the antenna arrays, the propagation of the coupled electromagnetic waves will be suppressed due to the negative permeability, so the isolation between the antenna arrays will be enhanced. For simplicity, the broadband decoupling performance of MM is verified by using patch antenna elements. Prototypes were fabricated and measured. Both simulated and measured results show that when the distance between the two antenna elements is about half a meter, the isolation can be enhanced by at least 25.0 dB in the whole X‐band, which convincingly verifies our method. This work provides an alternative to enhancing isolation between broadband antenna arrays and may find applications in electromagnetic compatibility of integrated masts, base stations, and so on. [ABSTRACT FROM AUTHOR]

In this article, we propose a design method of aperture-multiplexing metasurfaces using back-propagation neural network (BPNN), which can achieve independent wavefront modulation for orthogonally-polarized waves. To this end, we first propose a modified Jerusalem Cross (MJC) structure as the metasurface unit cell, which decouples orthogonal interactions by increasing the effective inductances of each of the two Jerusalem Cross (JC) branches. Due to the reduced orthogonal couplings, the MJC can achieve nearly independent control of orthogonally-polarized waves. Then, via BPNN, a dictionary mapping between reflection phase and structural parameters of MJC is established to facilitate metasurface design using MJCs. It is verified that the fitting degree of dataset exceeds 99.99% and that the prediction error of reflection phase is less than 0.01°. Using this design method, we demonstrated a focusing metasurface that can focus reflected waves for both $x$ - and $y$ -polarized waves simultaneously, with focus lengths of 150 and 300 mm, respectively. The simulated and measured results are well consistent, which prove the feasibility of this method. This work provides an efficient method of designing multiplexing and multifunctional metasurfaces, which may find applications in fields, such as satellite communication and base stations. [ABSTRACT FROM AUTHOR]

The vertical profile of |$C_n^2$| is the main factor for accurate astronomical observation and laser communication, however, hardware-based instruments and associated data are not widely available due to logistical and financial issues. In this article, we developed an indirect method, a hybrid network structure which is a combination of the backpropagation neural network and the simulated annealing algorithm, to fit the vertical profile of |$C_n^2$|⁠. Radiosonde measurements from a field campaign over the Tibetan Plateau at Dachaidan (37.7○N, 95.3○E, 3180 m ASL) were performed in 2020 August to estimate the accuracy of our model, during which a balloon-borne portable turbulence meteorological radiosonde was used to measure the atmospheric optical profiles. Besides, the integrated astronomical parameters (the coherence length r 0, seeing ε0, isoplanatic angle θ0, and the wavefront coherence time τ0), derived from |$C_n^2$| and wind-speed vertical profiles, are investigated for astronomical applications using the proposed model. In addition, quantitative evaluations such as the correlation coefficient, the root mean squared error, and the systematic bias are used to quantify the performance of our model. More interesting, this model is found to outperform a widely used external scale model for the prevalent atmospheric conditions and shows better correlation and reliable estimates. [ABSTRACT FROM AUTHOR]

Appropriate knowledge of wind-speed distributions and optical turbulence at existing and potential astronomical observatories is crucial for siting ground-based telescopes and applying adaptive optics (AO) systems. In this paper, the wind-speed and optical-turbulence characteristics above Gaomeigu and the Tibetan Plateau are studied by employing the 20-yr (1999–2018) European Centre for Medium-Range Weather Forecasts' fifth set of reanalysis data (ERA5). First, the meteorological parameters derived from ERA5 data are evaluated with coinciding radiosonde measurements. Results show that the meteorological parameters of ERA5 data in the free atmosphere have quite good reliability, with bias and root mean square error basically lower than 1.2 K in temperature and basically smaller than 2 m s−1 for wind speed. Then, vertical distributions and seasonal behaviour of the wind speed at Gaomeigu and Lhasa station above the Tibetan Plateau are analysed. Thirdly, the Richardson number (Ri) in the free atmosphere is calculated to provides us with a map of relative probability of different periods and regions of optical turbulence being developed above the two sites. In general, the atmospheric stability of Gaomeigu is higher than that of Lhasa station. Particularly in June, for Gaomeigu, the atmospheric stability within 6–30 km a.s.l. is basically superior or equal to the stable condition found at two mid-latitude sites: Oukaimeden and La Palma. Moreover, Lhasa station has a relative higher stability during June–September than other months. Furthermore, we provide the |$({C_n^2})$| profiles using ERA5 data at Gaomeigu and Lhasa. The results indicate that the choice of an appropriate outer-scale model is crucial for revealing local turbulence characteristics. [ABSTRACT FROM AUTHOR]

In this article, we propose a method of designing programmable coding metasurface with a reconfigurable number of reflected beams. Each unit cell of the metasurface is loaded with one varactor to enable adjustable phase responses. The bias, beneath the ground drilled with small holes, is connected to unit cells by a thin via through the holes, to avoid adverse influences on unit cells. To simplify the bias network, a super unit composed of $5 \times 5$ unit cells is taken as the coding element of realizing 2-D coding sequences. With different bias voltages, the unit cell will produce different reflection phases. By programming the bias voltages, the number and directions of reflected beams can be tailored due to different coding sequences. Under normal incident, reflected waves will be split into multiple beams whose directions can be flexibly controlled. We designed a prototype, implemented our design, and carried out experiments. Both the simulation and experiment results show that the number of reflected beams can be reconfigured between 1 and 5. Reflect beam number reconfigurability of such metasurfaces can be readily used as planar reflector of antennas and may find applications in wireless communications. [ABSTRACT FROM AUTHOR]

In this paper, we propose a method of designing broadside radiation antennas using metamaterial resonators. The antenna consists of a feeding probe and a nested metamaterial resonator (MR), where the latter is located in the near‐field zone of the former and both of them stand on the metallic ground. The nested MR, where a finite‐length comb structure (CS) is circled by a broadside‐coupled split‐ring resonator (BC‐SRR), is used as the radiator. Excited by the tilted electric fields around the feeding probe, even‐mode spoof surface plasmon polaritons (SSPPs) can be excited on the comb structure, forming standing wave, and leading to broadside radiation at the half‐wavelength frequency. The BC‐SRR is excited by the magnetic fields penetrating through it, leading to broadside radiation at its resonant frequency. A prototype working at 5.4 GHz and 7.0 GHz was designed, fabricated and measured. The measured and simulated results agree well and verify our design. [ABSTRACT FROM AUTHOR]

In order to solve the problem of vehicle scheduling to feed parts at automobile assembly line, this study proposes a just-in-time delivery method combined with the mode of material supermarket. A mixed integer linear programming model with the primary objective of using the least number of tow trains is constructed by considering capacity of vehicle and inventory levels of line. On the basis of the minimum number of tow trains, the schedule of each tour is reasonably planned to minimize inventory of assembly line, which is the secondary objective of the part supply problem. Additionally, a heuristic algorithm which can obtain a satisfactory solution in a short time is designed to solve large-scale problems after considering continuity and complexity of modern automobile production. Furthermore, some cases are analyzed and compared with the widely used periodic delivery strategy, and the feasibility of just-in-time model and algorithm is verified. The results reveal that just-in-time delivery strategy has more advantages in reducing inventory level than periodic delivery strategy. [ABSTRACT FROM AUTHOR]

In this communication, we propose a method of designing shared-aperture antennas based on excitations of both even- and odd-mode spoof surface plasmon polaritons (SSPPs). The antenna consists of a feeding monopole and a tapered SSPPs structure, both of which are placed vertically on a metallic ground. Due to tilted electric vectors of the monopole in near fields, both even- and odd-mode SSPPs can be excited. Standing waves of even-mode SSPPs on the SSPPs structure will enable broadside or tilted radiation, while traveling waves of odd-mode SSPPs on the tapered end will enable endfire radiation. Therefore, such an antenna configuration can achieve broadside, tilted, and endfire radiations. As an example, a shared-aperture antenna operating in $C/X$ /Ku-bands was designed, fabricated, and measured. Both the simulated and measured results verify that the antenna can achieve broadside radiation in 4.68–4.83 GHz, tilted radiation in 8.51–8.82 GHz, and endfire radiation in 11.00–17.38 GHz, with peak gains about 2.7, 3.5, and 6.8 dB, respectively. The antenna itself can work in multiple bands with customized radiation patterns, without using several antenna radiators and complex feeding network. This communication provides an effective method of designing shared-aperture antennas in future lightweight and multifunctional wireless communication systems. [ABSTRACT FROM AUTHOR]

In this paper, a low radar cross section (RCS) patch antenna is proposed, which is realized by engineering dispersion property of metamaterial absorbers (MAs). The dispersion curve of the MA consists of a weak linear regime with low insertion loss and an asymptotic nonlinear regime with strong absorption. By changing geometric parameters, the dispersion property of the MA can be engineered, so that the cutoff frequency is shifted freely, as well as the strong absorption band being changed. Thus, if the cutoff frequency of the MA is very close to the upper bound frequency of a patch antenna, the patch antenna will obtain polarization-independent low-RCS property out-of-band or in-band cross-polarized and out-of-band copolarized low-RCS properties by replacing the radiation patch with the modulated MA. For verification, a ${C}$ -band patch antenna with RCS reduction performance in ${X}$ -band is designed, fabricated, and measured. Both the simulated and measured results agree well and verify that the antenna achieves average gain about 5 dB in 7.2–7.7 GHz. To assess the RCS reduction performance of the proposed patch antenna, we fabricated a $5 \times 5$ antenna array. The measured results indicate that monostatic RCS of the array is decreased by more than 10 dB in the entire ${X}$ -band for copolarized and cross-polarized wave normal incidence than the metallic plate with the same area. [ABSTRACT FROM AUTHOR]

Inspired by the checkerboard metasurfaces, we propose the design of low-RCS multi-beam linearly polarized (LP) array antenna based on Pancharatnam–Berry (P-B) phase. The antenna array is composed of a number of split-ring resonators (SRRs) with a rotation angle $\alpha $ difference. For circularly polarized (CP) waves, each two adjacent SRRs exhibit $\alpha $ and $2\alpha $ P-B phase differences under feeding and normally illuminating, respectively. Because of this, the SRR array exhibits different phase gradients for radiated and reflected waves. To obtain multiple LP beams, reversed phase gradients for CP waves are alternatively arranged in 1-D or 2-D on the array, leading to two or four beams, respectively. Under normally illuminating, the reflection phases along the array form the checkerboard configuration, which can reduce both the in-band RCS and out-of-band RCS of the antenna array. As an example, we demonstrate a low-RCS four-beam antenna operating in ${X}$ -band. Both the simulated and measured results show that the maximal realized gain of each beam reaches up to about 13.6 dB at 10.2 GHz. To evaluate the RCS reduction performance, we measured specular reflection of the prototype under normal incidence. The reflection is reduced by more than 10 dB in 9.7–10.3 GHz and by more than 5 dB out-of-band in 10.3–14.0 GHz. The design method provides an alternative to the design of low-RCS and low-profile antenna arrays. [ABSTRACT FROM AUTHOR]

A novel spin‐selectivity absorbing coding phase gradient metasurface (SACPGM) is proposed and demonstrated. The coding element consists of spin‐selectivity absorbing unit cells, which exhibit different absorption characteristics for left‐handed circularly polarized and right‐handed circularly polarized incidence wave due to their spin‐selectivity absorbing properties. The scattering patterns of the SACPGM can be synthetically manipulated by the reflection of the spin‐selectivity absorbing unit cells, the phase gradient of the coding elements, and the coding sequences. As an example, a two‐bit SACPGM with random coding sequence is designed to reduce radar cross section (RCS) by a combination of absorption, beam deflection, surface wave coupling, and diffusion scattering. Both simulated and measured results agree well and demonstrate that the SACPGMs possess excellent performance for RCS reduction. This strategy can help realize stealth applications under bi‐static detections. [ABSTRACT FROM AUTHOR]

High-gain planar antennas always contribute large radar cross section (RCS) to low-observed platforms. To solve this contradiction, we propose a novel design of circularly polarized metasurface antenna characterized by low RCS but high gain. Split ring resonators (SRRs) play a twofold role as the array elements for linear polarization and as the unit cells of metasurface for RCS reduction (RCSR). Four $2 \times 2$ arrayed SRRs are positioned with orthogonal orientations as a super-array element (SAE) and fed with a phase shift of 90° in between for left-handed circular polarization. On the other hand, based on its original arrangement, the open-circuited SAE is also designed to be the super-cell of a (0°, 180°) reflective checkerboard metasurface. Owing to anti-phase energy cancellation and scattering, both the in-band and out-of-band RCS can be dramatically reduced. As indicated by the measurements in antenna, the fabricated prototype operating in $X$ -band exhibits a combined bandwidth (3 dB axial ratio (AR), 3 dB gain drop, and −10 dB impedance matching) of 16% with a maximum realized gain of 17.9 dB. Besides, under normal illumination, the measured specular reflection has been reduced by 10 dB within 9.2–10.8 GHz and by 7.5 dB from 10.8 to 14 GHz. This design method simultaneously ensures high-gain antenna performance as well as meets the requirement for low RCS. [ABSTRACT FROM AUTHOR]

This paper deals with stochastic dynamic facility layout problem under demand uncertainty in terms of material flow between facilities. A robust approach suggests a robust layout in each period as the most frequent one falling within a prespecified percentage of the optimal solution for multiple scenarios. Mont Carlo simulation method is used to randomly generate different scenarios. A mathematical model is established to describe the dynamic facility layout problem with the consideration of transport device assignment. As a solution procedure for the proposed model, an improved adaptive genetic algorithm with population initialization strategy is developed to reduce the search space and improve the solving efficiency. Different sized instances are compared with Particle Swarm Optimization (PSO) algorithm to verify the effectiveness of the proposed genetic algorithm. The experiments calculating the cost deviation ratio under different fluctuation level show the good performance of the robust layout compared to the expected layout. [ABSTRACT FROM AUTHOR]

In this paper, we propose the design of antennas with low radar cross section (RCS) based on dispersion engineering of spoof surface plasmon polaritons (SSPPs). The antenna consists of a feeding monopole and SSPPs guiding structure placed vertically on a metal ground. By comprehensively engineering the weak and strong dispersion regimes of the SSPPs structure, the cutoff frequency of SSPPs can be made close to the upper operating frequency of the feeding monopole. In this way, the SSPPs structure serves as a high-efficiency radiator in the operating band and as a broadband absorber out of band, leading to low RCS out of band. As an example, aC-band antenna with low RCS in theX-band was designed, simulated, and measured. Both the simulation and experiment results show that the antenna can radiate in theC-band, with average gain 6 dB and fractional bandwidth 28%. In order to evaluate the RCS reduction performances, a $5\times 5$ antenna array was fabricated and the mono-static RCS was measured. The measured results show that the mono-static RCS is reduced by more than 10 dB in the wholeX-band (8.0–12.5 GHz), with a maximal reduction above 30 dB. The design method provides an effective alternative to low-RCS antennas. [ABSTRACT FROM AUTHOR]

In this paper, a wide-angle flat corner reflector based on the multiple phase gradient modulated metasurface is proposed and demonstrated. Through designing the related gradient phase, the propagation direction of the reflected electromagnetic wave is just opposite to the propagation of the incidence wave based on the generalized version of the reflection law. This guaranteed a radar cross section (RCS) enhancement in the vicinity of this incidence direction. To derive a uniform mono-static RCS in a wide incidence angle domain, the flat metasurface corner reflector is decomposed into several regions with different areas, which are designed for RCS enhancing under wave incidence in different incidence directions. As an example, the metasurface corner reflector consisted of two different phase gradients operating over the X-band is designed to realize wide-angle RCS enhancement. The simulated results indicate that in the designed incidence directions, the reflected waves are all opposite to the incidence wave for both TE and TM polarized waves. To validate the RCS enhancement performances, the mono-static RCS of the designed metasurface corner reflector is measured. The measured results reveal good accordance with the simulations, and both demonstrated that the designed metasurface corner reflector obtains tremendous RCS enhancement performances in a wide-angle domain (−50°–50°) for both TM and TE polarized waves. [ABSTRACT FROM AUTHOR]

In this paper, a triple-band-pass frequency selective structure is designed by combining traditional frequency selective surfaces (FSSs) with the spoof surface plasmon polariton (SSPP) guiding structure array. The FSSs consist of Jerusalem cross unit cell array with dual-band-pass property. And the SSPP guiding structure array is composed of vertical metallic blade structure array with high-efficiency transmission by engineering the dispersion of SSPP. By arranging the FSSs above the SSPP guiding structure array, a null located between the two passbands is introduced, resulting in a triple-band-pass characteristic. Furthermore, the triple-band-pass frequency selective structure is simulated, fabricated and measured. Both the simulated and measured results agree well, and verify that the transmissivities are all higher than -0.5dB in three frequency ranges: 2.42-2.90GHz, 5.57-5.85GHz and 9.48-9.85GHz. And the transmissivities of stopbands are lower than -10dB in three frequency ranges: 3.12-5.46GHz, 6.65-7.89GHz and 10.32-15.20GHz. [ABSTRACT FROM AUTHOR]

A novel design of spoof surface plasmon polariton (SSPP) planar antenna is proposed based on the wave vector modulation of transmissive phase gradient metasurface (TPGM). The antenna consists of TPGM placed a certain distance above SSPP guided wave structure, exhibiting the directional radiation property according to the generalized Snell's law. As an example, an SSPP planar antenna fed by rectangular waveguide is designed by using a wideband polarization rotating TPGM. Simulated and experimental results, agreeing well with each other, show that the planar antenna can achieve wideband frequency scanning from backward to forward. Compared to existing planar antennas, our SSPP planar antenna has advantages of wideband frequency scanning characteristic, higher efficiency, and higher degree of freedom for designing frequency scanning antenna, which would possibly open an avenue in designing conformal antennas and other new types of antennas. [ABSTRACT FROM AUTHOR]

On the basis of generalized Snell’s law of reflection, we propose to achieve frequency scanning radiation by decoupling spoof surface plasmon polaritons (SSPPs) from a corrugated metallic strip (CMS). Phase gradient metasurface (PGM) is utilized to modulate the dispersion behavior of the CMS. Since the phase gradient of the PGM is contrary to the wave vector of SSPPs, the dispersion curve of SSPPs can be translated into the fast wave zone, leading to frequency scanning radiation. As an example, we demonstrate a frequency scanning antenna operating at 8.8–10.7 GHz. A prototype was designed, fabricated, and measured. The measured results show that the prototype can realize continuous beam scanning from 4.8° to 37.2°, with realized gain varying from 8 to 13.1 dB. Owing to surface confinement of SSPPs, the proposed method can be readily extended to the design of conformal frequency scanning antennas on curved faces. [ABSTRACT FROM AUTHOR]

Wireless link has need of an omnidirectional antenna like dipole, but with higher gains. Of course, there is no way of achieving both of them simultaneously. To solve this contradiction, we propose to design multibeam antennas, which divide the radiation pattern of omnidirectional antennas into several beams. The antenna, based on spoof surface plasmon polaritons (SSPPs) mode coupling, consists of a feed monopole and N double-side corrugated metallic strips circling around the feed. The fields of the feed are coupled into SSPP waves that propagate along the strips and radiate at the end, dividing the omnidirectional radiation pattern into several beams. Three X-band prototypes of multibeam antennas with different radiation characteristics were designed, fabricated, and measured. Both numerical simulations and experimental results verify that the antennas are efficient in generating multiple beams with high gain at the predesigned directions. [ABSTRACT FROM AUTHOR]

To determine serum cytokine profiles in Graves’ disease (GD) patients with or without active and inactive thyroid associated ophthalmopathy (TAO), we recruited 65 subjects: 10 GD only (without TAO), 25 GD + active TAO, 20 GD + TAO, and 10 healthy controls. Liquid chip assay was used to measure serum Th1/Th2/Th17 cytokines including IFN-γ (interferon-gamma), TNF-α (tumor necrosis factor-alpha), IL-1α (interleukin-1 alpha), IL-1Ra (IL-1 receptor antagonist), IL-2, IL-4, IL-6, and IL-17 and two chemokines: RANTES (regulated upon activation, normal T cell expressed and secreted) and IP-10 (IFN-γ-induced protein 10). Serum levels of TSH (thyroid stimulating hormone) receptor autoantibodies (TRAb) were measured using an enzyme linked immunosorbent assay. Compared with healthy controls, TAO patients showed significantly elevated serum levels of IFN-γ, TNF-α, IL-1α, IL-4, IL-6, IL-17, and IP-10. Comparing active and inactive TAO, serum Th1 cytokines IFN-γ and TNF-α were elevated in active TAO, while serum Th2 cytokine IL-4 was elevated in inactive TAO. Serum Th17 cytokine IL-17 was elevated in GD but reduced in both active and inactive TAO. A positive correlation was found between TRAb and IFN-γ, TNF-α, IL-1α, IL-2, IL-4, and IL-6. Taken together, serum Th1/Th2/Th17 cytokines and chemokines reflect TAO disease activity and may be implicated in TAO pathogenesis. [ABSTRACT FROM AUTHOR]

RNA replication of positive-strand (+)RNA viruses requires the protein-protein interactions among viral replicases and the association of viral replicases with intracellular membranes. Protein A from Wuhan nodavirus (WhNV), which closely associate with mitochondrial membranes, is the sole replicase required for viral RNA replication. Here, we studied the direct effects of mitochondrial membrane lipids (MMLs) on WhNV protein A activity in vitro. Our investigations revealed the self-interaction of WhNV protein A is accomplished via two different patterns (i.e., homotypic and heterotypic self-interactions via different interfaces). MMLs stimulated the protein A self-interaction, and this stimulation exhibited selectivity for specific phospholipids. Moreover, we found that specific phospholipids differently favor the two self-interaction patterns. Furthermore, manipulating specific phospholipid metabolism affected protein A self-interaction and the activity of protein A to replicate RNA in cells. Taken together, our findings reveal the direct effects of membrane lipids on a nodaviral RNA replicase. [ABSTRACT FROM AUTHOR]