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Flexible strain sensors capable of acquiring tiny mechanical signals and attaching to various irregular surfaces are becoming prevalent in physiological measurement, soft robotics, and human‐machine interaction. However, the advancement of flexible strain sensors is substantially impeded by the intrinsic compromise between sensitivity and the range of detectable signals. Inspired by the multilayer structure of nacre in nature, a carbon nanotubes (CNTs)/graphene (GR)/graphene (GR)/thermoplastic polyurethane (TPU) mat (CGGTM) is prepared by electrospinning and high‐pressure spraying technology. By designing a multilayer structure with mutually non‐interfering conductive networks, the resulting CGGTM possesses a low detection limit (0.05% strain), high sensitivity (gauge factor, GF > 152537), large detection range (up to 364% strain), fast response/recovery time (80 ms/100 ms), and excellent cyclic durability (up to 1000 cycles). Furthermore, the CGGTM also exhibits satisfactory triboelectric performances when assembled into a triboelectric nanogenerator (TENG, 3 × 3 cm2), including high triboelectric output (open‐circuit voltage Voc = 135.4 V, short‐circuit current Isc = 1.25 µA) and power density (88 mW m−2), enabling reliable power supply, self‐powered sensing, and pulse monitoring capability. Finally, CGGTM is successfully applied to the collection of biological signals and multi‐gesture motion recognition assisted by machine learning algorithms, which holds promise for intelligent interaction with gestures in the future. [ABSTRACT FROM AUTHOR]

The development of flexible piezoresistive sensors has increasingly attracted widespread attention due to their various potential applications in wearable devices, human–machine interfaces, and health monitoring systems. Developing high‐performance sensors that can accurately monitor movement and human health monitoring is very necessary. This study uses silver nanoparticles, MXene, and polypyrrole to prepare conductive fabrics based on various fabrics through layer‐by‐layer encapsulation. Finally, conductive fabrics with different layers were encapsulated to prepare a multilayer fiber sensor. Next, the series piezoresistive performance of sensors made of different fabric materials and sensors with different layers were tested. The experimental results show that the sensor prepared has the best performance when the selected fabric material is mulberry silk and the number of layers of the fabric is five. After testing, the sensitivity of the sensor is 4.9029 at low strain and 0.7901 at high strain. Moreover, it exhibits good stability during 1600 compression‐release cycles and temperatures range from −20 to 60°C. The designed sensor performs well in motion and human physiological signal monitoring. This study provides new ideas and references for the design and research of multilayer fiber sensors. [ABSTRACT FROM AUTHOR]

Chemical compatibility of water‐soluble azo‐dye photoalignment materials opens up new possibilities of thin‐film optical devices fabrication with advanced characteristics combining several polymerizable liquid crystal layers into multilayer structures of broadband quarter or half wave retarders. However when the azodye photoalignment layer is placed in‐between two layers of polymerizable liquid crystal significant increase of dye absorption is observed. Analysis of this 'Absorption Problem' concludes azodye inter‐layer field is the cause of polarization and cis‐trans equilibrium change. New water‐soluble azo‐dye photoalignment material AmA‐2522 is suggested as perspective problem solution. [ABSTRACT FROM AUTHOR]

The variable dielectric properties of multilayer structural ceramic/polyolefin composite film substrate materials with silicon dioxide (SiO2) and titanium dioxide (TiO2) powders as fillers and 1,2‐polybutadiene/styrene‐butadiene‐styrene triblock copolymer/ethylene‐propylene‐diene terpolymer/(1,2‐PB/SBS/EPDM) as polymer matrix were systematically investigated. Single‐layer SiO2, TiO2 and SiO2/TiO2/polyolefin‐based composite films denoted as A, B and H, respectively, were prepared by the flow casting method, and then multilayer structural composite substrates with different stacking methods were prepared by the hot pressing method. Four different layering modes were used: ABAB, AABB, ABBA, and BAAB. It was found that the dielectric constants of all four modes were within the scientific range. Compared to the other four types of laminated substrates, however, the fifth composite substrate with four identical film laminations made from a blend of two fillers (HHHH) exhibited better thermal stability and had a lower dielectric loss (0.00206) at 10 GHz compared to the other four types of laminated substrates. On the other hand, the other four types of laminated substrates have better mechanical properties compared to the hybrid substrates. This work provides a new idea for the preparation of oxide ceramic/polyolefin‐based dielectric composites that meet the requirements of different dielectric and thermomechanical properties. [ABSTRACT FROM AUTHOR]

High‐performance multilayer dielectric elastomer actuators (DEAs) are well‐positioned to overcome the insufficient output force and energy density as artificial muscles. However, due to the fabrication process, the multilayer DEAs with nonmodifiable structures often suffer from the limitation of short lifespans and scalable preparation. Herein, reusable multilayer DEAs with the detachable and reconfigurable structure are fabricated. This is achieved by realizing scalable compliant electrodes using the continuous spatial confining forced network assembly (CSNA) method and combining the vacuum lamination (VL) approach to have good attachability and detachability with the VHB dielectric elastomer. The flexible roller‐based CSNA method is used to prepare the large area compliant electrodes composed of α, ω‐dihydroxy polydimethylsiloxane and electrically conductive nanoparticles. The fabricated electrodes can continuously work over 10 000 cycles at 40% strained stretching and maintain smooth surfaces to construct multilayer DEAs. Moreover, owing to the detachable configuration of the DEAs, the electrodes can also be recovered and reused for building new actuators. The lower limb assistive device is demonstrated by detachable multilayer spring roll DEAs, achieving approximately 3.1 degrees of flexion and extension movement of knee models under a voltage of 7 kV. The detachable and reconfigurable multilayer DEAs shed new light on the applications of wearable assistive devices. [ABSTRACT FROM AUTHOR]

The interface of photovoltaic (PV) systems to the grid requires an efficient control strategy to operate, control, and improve power quality. The output voltage of the solar array, which may be accompanied by significant voltage variations, must be controlled and converted to a higher voltage for grid connection applications of photovoltaic system by a DC‐DC converter that commands more attention. Recently, due to the increasing use of renewable sources, multilayer structure with different structures and designs to provide power and stability has been researched because the output voltage of solar arrays is usually low, so it is increasing to DC‐to‐DC converters, needed with optimal interest and efficiency. In this paper, a method to improve the performance of DC–DC converter used in PV system by using a combined design of forward and fly‐back is presented. Due to the fact that isolated converters, flyback, and forward converters have a simple structure and are easy to control, but this converter is affected by high stress voltage. Therefore, this converter cannot be used for high power applications. To solve this problem, it has been improved in the proposed converter with the overlay and triple induction technique, which is a very good improvement on the voltage gain parameters in the short duty cycle. The voltage drop across the semiconductor switch is reduced. The investigations performed that the proposed DC/DC converter in Simulink MATLAB has been simulated. The results show that the suggested converter has an ideal efficiency of roughly 82.86% and provided higher voltage gain, decreased voltage stress, and reduced voltage jumps caused by disconnection. [ABSTRACT FROM AUTHOR]

In this study, ternary layered double hydroxide (LDH) containing Zn, Cu, and Ni was synthesized successfully using hydrolysis route. Upon calcination at a lower temperature of 350 °C, the synthesized lattice transformed into ZnO containing Cu and Ni that can be reformed back to the layered structure simply by a phenomenon known as 'memory effect'. Furthermore, the synthesized lattice was used for the formation of polyaniline (PANI)‐based composite material. The structural and morphological details of the as‐prepared samples were studied using various spectroscopic techniques, that is, powder X‐ray diffraction (PXRD), Fourier transform infrared (FTIR), thermo gravimetric analysis (TGA), and scanning electron microscopy‐energy dispersive X‐ray analysis (SEM–EDX), indicating the formation of single‐phase ternary LDH as well as the successful incorporation of PANI in the interlayer region. Owing to the combined advantages of LDH and conducting polymer (PANI), zinc copper nickel layered double hydroxide (ZnCuNi‐LDH)/PANI composite may be exploited as a potential candidate for a variety of applications in the future. [ABSTRACT FROM AUTHOR]

The electromagnetic interference (EMI) shielding performance of reduced graphene oxide (rGO) foam is restricted to its poor conductivity and macro‐monotonic structure. In this work, highly conductive MXene nanosheets are introduced into graphene oxide (GO) solution and multilayer structures were designed to improve the EMI shielding performance of graphene foam. The multilayer rGO/MXene composite foam shows an excellent EMI shielding effectiveness of more than ≈28 dB in C and ≈35 dB in X band. Meanwhile, it reveals an outstanding heat insulation performance equaling to air (0.025 W m−1 K). The macro multilayer and microporous structure plays a prominent role in the EMI shielding and heat insulation performance. This work provides valuable ideas for designing multifunctional EMI shielding materials for the next generation of smart electronic devices. [ABSTRACT FROM AUTHOR]

Summary: Community detection is a fundamental research problem in social networks. However, most existing research focuses on homogeneous networks while ignoring the multitopology and attributes in social media. In this article, we propose community detection algorithms based on community kernels to detect high‐quality communities in heterogeneous social networks. It is noticed that the social community has multiple topology structures, as nodes or users in social media networks have multiple attributions. For example, users can be friends and coworkers in a research group simultaneously. Hence, we propose a multilayer and attribute combined measure (MACM), a novel measurement based on the multilayer structure and common neighboring attributes, which includes the similarity measure between nodes and the importance measure for individual node in multilayer networks. Two improved community kernel detection algorithms based on MACM are subsequently proposed. They are the MA‐Greedy, which is based on the greedy algorithm, and the MA‐WeBA, which is a weighted balanced algorithm. The multilayer structure and attributes are comprehensively considered when calculating the similarity and importance of nodes in these strategies. Extensive experimental results on two public data sets demonstrate that the multilayer structure and attribute information can be used to enhance the precision of community detection. [ABSTRACT FROM AUTHOR]

High‐sensitivity profilometry provides valuable tools for measurement of the surface structure of a device. On the other hand, tomographic techniques such as ultrasound imaging or optical coherence tomography can be used to measure the inner structure of a device with micrometer resolution. However, the multilayer structure of a device such as a display panel cannot be measured with nanometer sensitivity using conventional profilometry and tomographic techniques. For this purpose, a new type of profilometry based on the technique of low‐coherence composite interferometer is proposed and demonstrated. With the phase compensation mechanism of the technique, phase fluctuation resulted from the instability of scanning component and environment can be significantly reduced and a high axial sensitivity can be achieved. The technique is demonstrated by measuring nine interfaces of a display panel with a displacement sensitivity of 11.73 nm without requiring any preknowledge on the structure and has the potential to become a new technique for inspecting the multilayer structure of a packaged device in industry. [ABSTRACT FROM AUTHOR]

Solid electrolytes (SEs) can potentially address the inherent safety problems of conventional organic liquid electrolytes. However, their low ionic conductivity and large interfacial resistance limit the practical applications of SEs. Here, a flexible solid electrolyte with a multilayer structure is fabricated by the UV curing of an interpenetrating network of poly(ether‐acrylate) (ipn‐PEA) in the Na3Zr2Si2PO12/poly(vinylidene fluoride‐hexafluoropropylene) porous skeleton (NZSP/PVDF‐HFP), exhibiting a high Na+ transference number of 0.63 and a suitable ionic conductivity of above 10−4 S cm−1 at 60 °C. In addition, due to the unique structure of the internal rigidity and external flexibility, the composite solid electrolyte can effectively mitigate interfacial ion transfer issues while guaranteeing a certain mechanical strength, and largely inhibiting the formation of dendrite and dead sodium. The solid sodium metal batteries using Na3V2(PO4)3 (NVP) as a cathode possess a discharge capacity of 85 mA h g−1 after 100 cycles at 0.5 C, and achieve above 90% of capacity retention rate during 100 cycles at 0.1 C for Na2/3Ni1/3Mn1/3Ti1/3O2 (NTMO) at 60 °C. The flexible solid electrolyte with multilayer structure shows a great advantage for managing the ionic conductivity and interface resistance problem, suggesting a promise as a practical sodium metal battery. [ABSTRACT FROM AUTHOR]

This article presents a new saliency detection method based on a hierarchical structure. In order to better capture the key elements in an image, we first construct a three‐layer structure by applying a merging strategy to the image. For different layers, we exploit different methods to detect salient regions. After obtaining initial saliency maps of five layers, we construct a Dempster‐Shafer model to fuse and refine these saliency maps. In the Dempster‐Shafer model, the saliency value of upper layers can provide guidance for saliency detection of lower layers. Finally, we fuse the saliency map of each layer to obtain the final result. Abundant experimental results on two benchmark data sets demonstrate that our method outperforms most of 12 state‐of‐the‐art methods in terms of three popular evaluation criteria, that is, the P‐R curve, the F‐measure, and the mean absolute error. [ABSTRACT FROM AUTHOR]

The level set method based on bias correction can segment images with gentle intensity inhomogeneity effectively. However, most level set methods fail to segment severe inhomogeneous images due to the use of fixed scale clustering criterion. To deal with this problem, an adaptive multilayer level set method is proposed to segment images with severe intensity inhomogeneity. First, an improved global adaptive scale operator and a local adaptive scale operator are designed to adaptively adjust the scale of clustering kernel function according to the degree of intensity inhomogeneity. Then, an adaptive multilayer level set structure is constructed with the two designed scale operators. The number of layers and the scale of each layer in the multilayer structure are adaptively determined based on the degree of intensity inhomogeneity, which not only provides appropriate candidate scales in each pixel but also allows the model to detect global contrast information. With the dual minimisation method, image segmentation and bias correction can be achieved simultaneously. In addition, a hybrid bias field initialisation procedure is proposed to enhance the robustness of the proposed method. Experimental results demonstrate the effectiveness and robustness of the proposed method in segmenting images with intensity inhomogeneity. [ABSTRACT FROM AUTHOR]

In wide band electromagnetic absorbers, absorption in high and low frequency domain usually influence each other. Rasorber structure with blocking gate resonator (BGR) sub‐wavelength unit surface is proposed and applied in electromagnetic wave absorber to resolve this problem. The absorber has −10 dB low‐reflectivity performance operating in bandwidth ratio 161.2% and approaches Rozanov's theory limit in low frequency. BGR unit surface also generate a 2‐step design method for multi‐layer absorber structure. Rasorber BGR unit surface helps to enhance low frequency absorption with limited thickness while maintain absorption in relative higher wide frequency range by impedance matching at low frequency. Sample fabrication and experiment measurement basically testify the numerical speculations. [ABSTRACT FROM AUTHOR]

This Letter presents an irregular pentagonal patch array antenna with a multilayer structure for dual‐band and multimode orbital angular momentum (OAM) generation. An irregular pentagonal patch antenna with U‐shaped slots resonating at different frequencies is designed as the array's element. The proposed antenna array consists of two uniform circular microstrip antenna arrays and two phase‐shifting feeding networks. It can be used to generate OAM mode l = − 1, 1 at 3 GHz and OAM mode l = −2, 2 at 6 GHz. The simulated near‐field phase distributions images of different OAM modes are obtained, which have verified the OAM generation. This proposed array antenna has the possibility to generate a total of six different OAMs in three frequency bands, by changing the number of array elements and optimising the irregular pentagonal patch antenna. This design may provide a new idea for the generation multimode vortex electromagnetic wave. [ABSTRACT FROM AUTHOR]

Summary: Metal hydrides are promising means for compact hydrogen storage. However, the poor heat transfer in the tank packed with metal hydride powders often hinders the system from charging or discharging hydrogen effectively. In this investigation, a tube‐fin heat exchanger is supposed to be inserted to the tank, and an optimization problem accounting for both heat transfer enhancement and cost is formulated. We solve the problem with approximate analytical methods, and the influences of fin geometry are discussed. The comparison results support using quadratic curve‐shaped fins, whose effectiveness is also proved by the numerical simulation results. Furthermore, a novel multilayer fin structure with varying width is proposed, and the key parameters of it are discussed, including the number and the arrangement of fins. This paper is expected to provide new insights for the heat transfer enhancement design of hydride‐based hydrogen storage system. [ABSTRACT FROM AUTHOR]

A bulk multilayered copper with nano‐sized grains (NG) as hard layer and ultrafine grains (UFG) as soft layer with the thickness ratio of about 10:1 is synthesized by electrodeposition. Microstructural studies by scanning electron microscope (SEM) and transmission electron microscope (TEM) reveal the alternating growth of well‐defined layers with either nano‐grains or ultrafine‐grains. Tensile tests reveal that the layered nanostructured Cu exhibits an enhanced ductility of near 17.5% and high ultimate tensile strength of about 700 MPa. The multilayered Cu exhibits a higher ductility without obvious loss of strength compared to the monolithic nano‐grained Cu. The enhanced ductility is primarily attributed to two effects including the increased strain hardening ability and the effective adjustment to the local stress concentration brought by the periodic existence of the UFG layer in the NG matrix. [ABSTRACT FROM AUTHOR]

In this article, a novel Ultra-Wideband (UWB) 180° planar phase shifter is designed and fabricated. The proposed design is mainly based on coupled sections which are realized by inserting slots into the common ground plane of the multilayer circuit. Two identical structures, leading to discard parameters that disturb the output phase shift, are introduced in the design. To get 180° phase difference shift, via holes are used to perform a short circuit in one of the two coupled sections. Theoretical analysis based on four port network is presented to explain the characteristics of the proposed design. Further, experimental measurements are performed and compared with simulation results to validate the proposed approach. Hence, a good simulated to measured agreement is obtained. [ABSTRACT FROM AUTHOR]

The size of representative microstructural samples obtained from atomic force microscopy is addressed in this paper. The case of an archetypal one-dimensional nanolayered polymer blend is considered. Image analysis is performed on micrographs obtained through atomic force microscopy, yielding statistical data concerning morphological properties of the material. The variability in terms of microstructural morphology is due to the thermomechanical processing route. The statistical data is used in order to estimate sample size representativity, based on an asymptotic relationship relating the inherent point variance of the indicator function of one material phase to the statistical, size-dependent, ensemble variance of the same function. From the study of nanolayered material systems, the statistical approach was found to be an effective mean for discriminating and characterizing multiple scales of heterogeneity. [ABSTRACT FROM AUTHOR]

Background and purpose Extensive skin wrinkling during facial expressions is one of the considerable problems in aesthetic dermatology. Although a few in silico studies have been performed with the aim of revealing the mechanism of a wrinkled appearance, there have been few studies that take into account the influence of skin roughness (i.e. microrelief), which exists on human skin in vivo. In this study, finite element simulations were performed using multilayer skin models with microrelief to investigate how extensive wrinkling appears on human skin, especially focusing on the role of surface roughness in the wrinkling mechanism. Methods Linear and post-buckling analyses were performed on soft elastic laminate models using the finite element method. A simplified multilayer model of human skin was employed to examine the contribution of skin's multilayer structure to the large-wrinkle mechanism. Microrelief was included in the model to assess its effect on the mechanism. Results A large wrinkle was observed as dermal buckling following a number of buckling events on the stratum corneum. The existence of microrelief had an effect on the suppression of dermal buckling. Conclusion Skin's multilayer structure should play a major role in the appearance of large wrinkles on human skin via its post-buckling behavior. This study suggested that fine microrelief on the skin surface hampers large wrinkles. These findings should be valuable for the development of cosmetic or medical treatments to prevent unfavorable skin deformations. [ABSTRACT FROM AUTHOR]

A new method for achieving amplitude reconfiguration in a reflectarray antenna is presented in this Letter. An individual unit cell is a compact multilayer structure, including a silver inkjet‐printed layer for rapid prototyping of the reflectarray. A small infrared light emitting diode (IR‐LED) illuminating a silicon wafer provides the reconfiguration in the system. Various illumination intensities of the IR‐LED allow for differing magnitudes of reflection from the unit cell. This provides the potential for radiation pattern tapering or amplitude modifications of the gain of the reflectarray. Simulation and measurement results for a single unit cell are presented here, with the matching between measurement and simulation also allowing for the change in the values of conductivity of the silicon to be extracted. [ABSTRACT FROM AUTHOR]

Male wing colors and wing scale morphology were examined for three species of lycaenid butterflies: Chrysozephyrus ataxus, Favonius cognatus and F. jezoensis. Measurement of spectral reflectance on the wing surface with a spectrophotometer revealed species-specific reflection spectra, with one or two peaks in the ultraviolet and/or green ranges. Observations of wing scales using an optical microscope revealed that light was reflected from the inter-ridge regions, where transmission electron microscopy revealed a multilayer structure. Based on the multilayer dimensions obtained, three models were devised and compared to explain the measured reflectance spectrum. The results showed that the best fit is a model in which thicknesses of thin films of the multilayer system are not constant and air spaces between cuticle layers are more or less packed with cuticle spacers. This suggests that the specific wing colors of the species examined are produced by the species-specific arrangement of the multilayer structure of wing scales. [ABSTRACT FROM AUTHOR]

A novel method based on femtosecond laser-induced forward transfer for high-throughput and efficient fabrication of periodic multilayer plasmonic metamaterials is demonstrated. With precisely controlling laser raster path applied on sputtered multilayer thin films, the laser-ablated materials can be transferred to another substrate leaving the fabricated multilayer structure on the original substrate. Subsequently, three-dimensional metamaterials can be made by multilayer structuring. Moreover, all the experimental results show that to create such multilayer split resonant rings (SRRs) with uniform profile, the laser fluence should be fine controlled under proper conditions. The optical property of fabricated multilayer SRR array is investigated by optical measurements and finite-difference time-domain simulations, showing various resonant modes in the middle-IR region. The calculated induced current distributions exhibit rich resonance properties of the structures as well. This work markedly extends the laser direct writing technique to a wide application in fabricating complicated metamaterials and plasmonic devices efficiently. [ABSTRACT FROM AUTHOR]

Electro‐optic (EO) properties at 7 K of a guest–host type nonlinear poled polymer system consisting of AJLZ53 chromophores in an amorphous polycarbonate host are reported for the first time. A modified attenuated total reflection method that takes into account multilayer structure is used to accurately characterise linear and nonlinear optical properties. At the telecommunication wavelength of 1550 nm, <10% drop of the EO coefficient r33 at 7 K is observed compared with that at 300 K, while n3r33 only decreases <5% because of increased anisotropic indices of refraction at low temperatures. This decrease of the r33 at 7 K indicates that the EO activity of nonlinear polymers at room temperatures is not of pure electronic origin because of vibrational mode contributions to the first‐order hyperpolarisability. [ABSTRACT FROM AUTHOR]

A novel, multilayer fractal PBG is presented here as the substrate for a microstrip line and the resulting configuration builds a low-pass filter of wide stopband. Experimental results in comparison with the corresponding two filters with monolayer PBG show that the proposed filter drastically enhances the width of the stopband. [ABSTRACT FROM AUTHOR]

This paper presents the design and test data for six-finger Lange couplers on a 3 mil GaAs substrate using the multilayer MMIC process. We achieved coupling of 3.3±0.5 dB, isolation greater than 20 dB, and return loss better than 15 dB over most of the 8–16 GHz frequency range. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 322–327, 2001. [ABSTRACT FROM AUTHOR]

A new self‐packaged bandpass filter by using multilayer print circuit board technology is proposed and investigated. By using a multilayer structure, a lumped step‐impedance resonator as well as self‐packaging, the designed filter can achieve a much more compact size, low insertion loss and a wide stopband. The implemented filter operated at a centre frequency of 800 MHz with a 3 dB bandwidth of 120 MHz demonstrates stopband rejection better than 25 dB up to 4 GHz. The measured insertion loss including the connector loss in the input and output is 1.48 dB. The size of the filter is only 12 × 8 mm, i.e. 0.059λg × 0.039λg. [ABSTRACT FROM AUTHOR]

This article presents a compact hairpin bandpass filter using multilayer stripline folded quarter-wavelength resonators in a low-temperature cofired ceramic substrate.Using the new structure designs accomplish the vertical coupling in multilayer system, the size of the proposed filter can be reduced about 50% compared to an equivalent single-layer hairpin resonator filter. As an example, an L-band filter centered at 1.10 GHz with a fractional bandwith of 13.5% is designed, fabricated, and measured. The measured results of the fabricated filter agree very well with the electromagnetic simulations. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2627-2629, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27139 [ABSTRACT FROM AUTHOR]

In this paper, a co‐design of filtering antenna based on multilayer structure is proposed for modern wireless communication systems. The filtering antenna system consists of a filtering network partly designed on two dielectric substrates and a Г‐shaped antenna, which performs as both a radiator and the last order of the filter. An effective co‐design method based on parameter extraction for impedance matching can significantly reduce the optimization time. Furthermore, a slot is grooved on the common ground, which is shared by the antenna and the filter to realize the feeding of the resonator. A prototype of the filtering antenna was fabricated and measured, and a good agreement is achieved. The tested results show that the filtering antenna features a 2.7% bandwidth, 2.2 dBi gain at 2.6 GHz and −20 dB out of band rejection at 5 × f0. The size of the design is 0.29λg × 0.23λg. [ABSTRACT FROM AUTHOR]

The results of a recent investigation of a high-gain microstrip reflectarray are presented. The substrate–superstrate resonance technique is used to increase the reflectarray gain. The measured gain is increased by 5 dB when the superstrate layer is added. Gain and radiation patterns are discussed. In order to use this technique in reflectarrays with phase-control elements, the analysis and discussion of the phase reflected by a particular unit cell made up of a slotted and grounded patch are presented. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 152–154, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20928 [ABSTRACT FROM AUTHOR]

Achieving high areal capacity is a challenge for current lithium‐ion batteries (LIBs). To address this issue, nickel foam (NF), as a free‐standing skeleton suffers from long‐term poor anchor ability for active materials, resulting in detachment from conductive substrates. In addition, the weighty NF damages the overall energy density of the electrode. Herein, an in situ fabrication of interlayer strategy is proposed to effectively address these issues through constructing layer‐by‐layer a 3D structure composed of an inner conductive framework, medial NiO layer, and outer few‐layer NiO nanoflowers in turn (NiO@NiO/NF). The interlayer derived from partial oxidation of NF not only reinforces the attachment of the active layer on NF but also contributes capacity to the whole electrode, leading to excellent stability and areal capacity. When used as the anode of LIBs, ultrahigh reversible capacity of 1.98 mAh cm−2 is delivered at 1.20 mA cm−2. The electrode still maintains good integrity and flexibility after 1000 cycles, showing good structure stability. Compared with previous reports, NiO@NiO/NF is one of the most outstanding NiO‐based electrodes. This work proposes a feasible strategy to enhance the capacity and stability of self‐supporting electrodes, and opens a new avenue for high‐areal‐capacity anode of LIBs. The five‐layer structure composed of inner conductive framework, medial NiO adhesive, and outer few‐layer NiO nanoflowers in turn is fabricated. The NiO interlayer derived from partial oxidation of NF not only reinforces the attachment of the active layer on NF but also contributes capacity to the whole electrode, leading to excellent stability and areal capacity. [ABSTRACT FROM AUTHOR]

A novel multilayer fractal photonic bandgap (PBG) is presented as the substrate for a microstrip line and resulting configuration builds a low-pass filter (LPF) of wide stop-band. Experimental results in comparison with the corresponding two filters with monoplayer PBG show that the proposed filter drastically enhances the width of the stop-band. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 431–432, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11401 [ABSTRACT FROM AUTHOR]