A double-layer highly efficient and wideband transmitarray antenna is presented. The element composed of four metal vias two crosspatches with stubs. penetrate the entire substrate arrange symmetrically. are printed on both sides dielectric substrate. introduced to enhance coupling strength. stubs added ensure a sufficient phase shift range. achievable transmission magnitude greater than -2 dB, range exceeds 360° within whole band. using proposed was designed, manufactured, measured....

A reflect-transmit-array antenna (RTA) with dual-operating modes is proposed in this letter. The RTA, which has a three-layer structure without air layers, can achieve reflectarray-mode (RAM) at 11-14 GHz and transmitarray-mode (TAM) 15-19 GHz. When the incident electromagnetic (EM) wave y-polarization, RTA operates RAM, reflected EM y-polarization. In comparison, TAM transmitted circular polarization (CP) when x-polarization. dual-mode wideband been fabricated measured to validate design....

The design and analysis of a dual-band equal-split Wilkinson power divider are presented in this paper. structure the formulas used to determine parameters have been given. has two output ports shifted away from isolation resistor open stub. As result, bandwidth can be enhanced obviously for small band-ratios. Closed-form equations derived using even- odd-mode formulation. For verification, microwave operating at 1 2 GHz is fabricated, experimental results show that designed fulfills all...

Abstract This paper considers the discrete‐time ${\cal H}_2$ output tracking control of wireless networked systems (NCSs) where time delays are modeled as Markov chains. Output can find many applications in industry. In order to reduce conservativeness and achieve better performance, designed state feedback controller is dependent on available sensor‐to‐controller controller‐to‐actuator delays. Then, formulated closed‐loop system a special jump linear governed by interdependent parameters...

Abstract Liquid metals (such as gallium or Ga) exist in liquid states under ambient conditions and are hardly sculpted chiral structures. Herein, through electron‐beam evaporation of Ga, hemispherical achiral Ga nanoparticles (NPs) randomly immobilized along helical surfaces SiO 2 nanohelices (NHs), functioning a template. Helical assembly NPs shows chiroplasmonic optical activity owing to collective plasmon–plasmon interactions, which can be tuned function pitch ( P ) the amount evaporated....

In this work, a method for rapidly and accurately determining the single-cut far-field (FF) patterns of any polarized linear antenna array, termed as quasi-far-field mathematical absorber reflection suppression (QFF-MARS), is introduced. The proposed QFF-MARS takes advantage cylindrical wave expansion (CWE) theory able to exclude interference from scatters at QFF range. method, probe compensation not needed, owing fact that measurement procedure same FF. It only required distance an under...

This article introduces an improved Gerchberg-Papoulis algorithm (IGPA) to resolve truncation errors in planar near-field (NF) antenna measurement and seeks define the most accurate means of recovering patterns. The NF measurements can be reduced by considering evanescent modes introducing a new convergence criterion window function IGPA. A detailed design procedure is presented, its effect on field distribution key parameters discussed, which found Appendix at...

Metallic chiral nanoparticles (CNPs) promisingly function as asymmetric catalysts but lack an important study in thermal stability of optical activity that stems from metastable lattices. In this work, annealing is applied to silver (Ag) CNPs, fabricated by glancing angle deposition (GLAD), and causes elimination at 200 °C, mainly ascribed chiral-to-achiral lattice transformation. The Ag CNPs are remarkedly enhanced through alloying with aluminum (Al) via layer-by-layer GLAD generate binary...

In this letter, a novel integrated physical optics (PO) method for calculating high-frequency scattering of nonplane wave is proposed, and the orbital angular momentum (OAM) upon an electric-large metallic sphere illustrated. A high-order Bessel expanded by series plane spectra selected to irradiate perfect electric conductor sphere. Combining PO approximation, scattered field from facet element calculated, total effect obtained vector superposition all facets. The calculated results are...

The driver's reaction time (DRT) is an important parameter of driving safety. In the current study, a new method based on combined use cross-correlation analysis and gray correlation was developed to calculate DRT during car following. Furthermore, assumed model normal distribution with simple complex as variables verified by values calculated from data experimentally collected road test. study provides useful information about calculation following, very meaningful in terms enhancement

<p style='text-indent:20px;'>In this paper, we study the long term dynamical behavior of a two-dimensional nonlocal diffusion lattice system with delay. First some sufficient conditions for construction an exponential attractor are presented infinite dimensional autonomous systems Then, existence attractors delay is established by using new method tail-estimates solutions and overcoming difficulties caused operator multi-dimensionality.</p>

This paper presents a software architecture for engraving machine control system based on hierarchical finite state and multithread programming. Interactive sequence diagram dataflow chart are described in detail manual automatic operation mode, which provides consistent flexible way to construct CNC system.

This paper studies the design of a robust discrete-time sliding mode control (DT-SMC) for high precision electro-hydraulic actuator (EHA) system with nonlinear friction. Nonlinear friction in hydraulic can greatly influence performance and accuracy actuators; however, it is difficult to accurately model characteristics. In this paper, proposed characterize frictions as an uncertainty matrices. Indeed, effects variations coefficients are considered norm bounded uncertainties that span region...

A bilateral Vivaldi antenna with reduced radar cross-section (RCS) is presented. The method for RCS reduction of vivaldi based on substrate integrated waveguide structure. Compared a traditional antenna, the monostatic proposed to as much 35dB at 7GHz without degradation performance.

This paper studies the influence of machine slideway precision on overall accuracy tools, and puts forward root causes decline in tool guide is rail wear, will impact adjacent unit cell, thus machined parts; Finally takes floor-type milling & boring as research object, bases geometric error models theory multi-body system to describe spindle box wear trends establish relationship between precision.

Based on the excellent and broad prospect of vortex beams in military application, it is necessary to evaluate scattering characteristics classical Bessel beam upon a perfect electrical conductor (PEC) blunt cone model aircraft structure. First, expanded by series plane wave spectra. Then, combining physical optics (PO) method, scattered field object fitted facet elements can be calculated. The amplitude, phase, orbital angular momentum (OAM) spectra for different attitudes are discussed...

Embedded control systems play a very important role in the modern industry, which fulfill various complicated and durable tasks automation industry. A typical embedded system consist of microprocessor based hardware set software running on top it. Due to rapid upgrading function changing, life cycle becomes shorter shorter. For current solution, it is usually lack reconfigurability secondary development ability. This makes reusing existing design hard, involves intensive modification or even...

In this paper, a new application scenario for the conformal reflectarray is proposed. A element composed of split ring and two arcs acting as phase shift lines adopted. The between 0° 360° achieved by adjusting length arc lines. distribution calculation method proposed to achieve 10-dB enhancement monostatic radar cross section (RCS) at 15° 30° tail missile. Projectiles (missile body) with without are fabricated measured. Measurement results showed that projectile achieves RCS in angular...

In article number 1807307, Ken Cham-Fai Leung, Yonggang Yang, Zhifeng Huang, and co-workers report silver chiral nanoparticles (AgCNPs) with a sub-5 nm helical pitch lead devised for the enantioselective amplification of optical activity adsorbed enantiomers axial chirality, probably owing to enantiospecific adsorption on surface lattices AgCNPs.

An efficient near-field measurement technique for predicting far-field monostatic RCS of targets is studied. In the case that height target sufficiently small so criterion satisfied in vertical direction, theory and algorithm to transformation this are derived. With perfect conductor cylinder as under test, computer simulation performed. The calculation results show obtained by agrees with calculated directly EM software FEKO very well, which proves correctness validity technique.

The platform of "Transportation Economic GIS Civil Aviation" is sub-product civil aviation execution operation management and technology. It can manage visually analyze the information data air-transportation resources about distribution cities, airlines, airports, ability transportation, other air-lines based on geography range [1].

By analysing the processing characteristics of varied diameter slender shaft parts, and according to basic vibration theory shaft, a production machine is designed,moreover, solution with flexible hydraulic follower rest elastic tailstock adopted creatively. Experimental results show that this tools can effectively improve radial dimensional accuracy,surface quality efficiency parts it has wide range engineering significance.