Numerical simulations are used to study the electromagnetic scattering from phase agile microstrip reflectarray cells which exploit voltage controlled dielectric anisotropy property of nematic state liquid crystals (LCs). In computer model two arrays equal size elements constructed on a 15 mum thick tuneable LC layer were designed operate at center frequencies 102 GHz and 130 GHz. Micromachining processes based metallization quartz/silicon wafers an industry compatible LCD packaging...

A frequency selective surface (FSS) which exploits the dielectric anisotropy of liquid crystals to generate an electronically tunable bandpass filter response at D Band (110-170 GHz) is presented. The device consists two printed arrays slot elements are separated by a 130-mum thick layer crystals. 3% shift in passband occurs when substrate permittivity increased applying control signal 10 V. Measured results show that insertion loss increases from -3.7 dB -10.4 resonance (134 GHz), thus...

The design, construction and measured performance is described of an offset parabolic reflector antenna which employs a reflectarray subreflector to tilt the focused beam from boresight direction at 94 GHz. An analysis technique based on method moments (MoM) used design dual-reflector antenna. Numerical simulations were employed demonstrate that high gain pattern can be tilted predetermined angle by introducing progressive phase shift across aperture reflectarray. Experimental validation...

A highly diastereo- and enantioselective [3+2] cycloaddition reaction of N-2,2,2-trifluoroethylisatin ketimines 3-alkenyl-5-arylfuran-2(3H)-ones was developed with 1 mol% thiourea-tertiary amine as the catalyst. series spiro[pyrrolidin-3,2'-oxindoles] bearing four consecutive stereocenters, including two vicinal spiro-quaternary chiral centers, were efficiently obtained excellent results (up to >99% yield, >20 : dr, ee).

A printed reflectarray antenna, which generates a beam that can be electronically switched from sum to difference radiation pattern, is presented. This achieved by applying bias voltage of 20 V one-half the aperture, constructed above 500 µm cavity containing liquid crystals. Simulated results are shown in good agreement with measurements at X-band.

As the economy develops and urbanization progresses, amount of arable land continues to decline. In this context, cultivation double-season rice is particularly important for enhancing yield per unit area. However, research on physiological mechanisms that contribute high yields in early varieties with short growing seasons still limited. To address gap, we conducted a field study using two varieties, Zhongzu18 Yongxian15, examine their production characteristics, photosynthesis,...

Planar microstrip Y-junction circulators have been fabricated from metallized 130-/spl mu/m-thick self-biased strontium hexaferrite ceramic die, and then bonded onto silicon die to yield integrated circulator circuits. The impedance matching networks needed transform the low-impedance outputs were deployed on low-loss alumina or glass dielectrics minimize circuit losses. These magnetically show a normalized isolation insertion loss of 33 2.8 dB, respectively, 1% bandwidth for an 20 dB....

Retinal ischemia-reperfusion (RIR) injury refers to an obstruction in the retinal blood supply followed by reperfusion. Although molecular mechanism underlying ischemic pathological cascade is not fully understood, neuroinflammation plays a crucial part mortality of ganglion cells.Single-cell RNA sequencing (scRNA-seq), docking, and transfection assay were used explore effectiveness pathogenesis N,N-dimethyl-3β-hydroxycholenamide (DMHCA)-treated mice with RIR DMHCA-treated microglia after...

Numerical and measured results are employed at X-band to demonstrate that the electrical properties of nematic state liquid crystal can be exploited produce phase shifters for beam scanning printed reflectarray antennas with a tunable range greater than 180°.

This paper proposes a novel scheme to solve the target localization problem by using combined measurements of received signal strength and angle-of-arrival (AOA) hybrid in three-dimensional (3D) wireless sensor networks (WSNs). The proposed can work effectively both cases known unknown transmit power. In power case, polarized identity, we transform available AOA into norm form establish new relationships between location, method is then second-order cone programming relaxation technique....

In this paper, we consider the received signal strength-based cooperative localization problem in both known and unknown transmit power of target nodes. For case power, treat as a constant derive novel non-convex weighted least squares estimator which can be transformed into second-order cone programming (SOCP) for reaching an efficient solution. additional parameter propose hybrid maximum likelihood-SOCP algorithm to alternatively estimate node locations power. Simulation results confirm...

Experimental results at X-band are used to compare the electromagnetic scattering from a printed reflectarray cell, which is constructed on 500 µm thick layers of three different nematic state liquid crystals. It shown that small voltage can be vary permittivity tunable substrate and thereby control phase reflected signals. Numerical using Ansoft HFSS compared with measured phase, resonant frequencies signal attenuation for two orientations crystal molecules. Data fitting employed quantify...

Multi-port DC/DC converters have been widely employed in stand-alone renewable power systems to provide stable and continuous the electrical loads. A full-bridge three-port converter (FB-TPC) interfacing a source, storage battery, load is proposed. The proposed FB-TPC integrates two Buck-boost into primary side of topology, magnetizing inductor transformer functions as an inductor. Single stage conversion between any three ports achieved, zero-voltage-switching for all switches are achieved....

With the advancements in silicon carbide (SiC) power devices, solid state transformer (SST)-based delivery architecture shows advantages over traditional line-frequency transformer-based solution terms of efficiency, density, modularity, and scalability. This article presents a three-level converter cell for modular SST, which consists neutral-point-clamped (NPC) H-bridge ac-dc stage series-half-bridge (SHB) LLC dc-dc stage. Compared with two-level cell-based total number is reduced to half,...

This paper presents a novel cost-effective microwave phase-shifter technology using thick-film ferroelectric varactors as the tuning component. The devices are fabricated by conventional screen-printing techniques with silver/platinum conducting layers and Ba <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.7 </sub> Sr xmlns:xlink="http://www.w3.org/1999/xlink">0.3</sub> TiO xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> tunable dielectric...

An efficient organocatalyzed enantioselective conjugated addition of sodium bisulfite to β-trifluoromethyl-α,β-unsaturated ketones using a cinchona alkaloid-derived squaramide catalyst is presented. A series optically active sulfonic acids, bearing tertiary stereocenter connecting CF3 group and SO3H group, were obtained in excellent yields with high enantioselectivities (up 99% yield 97% ee) under mild conditions. This method will provide an efficient, economic, green route access chiral...

A novel RF small-signal model in the form of a physics-based equivalent circuit for advanced bulk FinFETs is proposed. Based on unique multifin structure, parallel resistance-capacitance branches are introduced to account gate-source and gate-drain admittances. The deembedding carefully performed after its effectiveness verified by accurately modeling pad interconnect parasitics. An analytical method developed directly extract parameters from measurements. validated 7 14 nm FinFET...

With the advancements in wide-bandgap power devices, solid state transformer (SST) becomes attractive to industry due its merits of high efficiency and density, modularity, scalability. However, complexity cost remain obstacles widespread adoption. This article presents a unidirectional SST with cascaded three-level bridgeless factor correction rectifier stage series-half-bridge (SHB) <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LLC</i>...

The impact of process variation to advanced integrated circuits has become increasingly significant. Traditional sampling based yield analysis and optimization always require large amount expensive simulations. This paper proposes an All Sensitivity Adversarial Importance Sampling (ASAIS) method, which avoids samplings in outer on sensitivity. Moreover, Fast (FSIS) method is adopted as inner eliminate the using transient sensitivity analysis. Experiments SRAM show ASAIS generates more than...