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The shape memory effect exhibited in ferroelectric ceramics, arising from the stable non-180° domain switching induced by an electric field, is highly sought after for its potential applications in actuation. However, the absence of a quantitative description between shape memory and the electric field has hindered ferroelectric shape memory actuators from achieving precise maintainable displacement outputs. In this work, an effective method for regulating shape memory by controlling stable non-180° domain switching is introduced. By investigating and modeling non-180° switching of domains, a quantitative relationship between shape memory and the driving electric field is established. The quantification of shape memory attenuation and the conduction of dynamic analysis have contributed to develop a method for regulating the maintainable displacement of ferroelectric shape memory actuators. The results demonstrate that this method can effectively regulate the maintainable displacement, achieving a maximum trajectory error of less than 2.5 %, while holding robustness to variations in driving frequency and load force. This work presents an approach for regulating shape memory actuators and has the potential to drive further advancements in ferroelectric shape memory ceramics. [Display omitted] • The quantitative relationship between shape memory and the driving electric field is established. • The maintainable displacement control method has been further improved. • The method can effectively regulate maintainable displacement, achieving a maximum trajectory error of less than 2.5 %. [ABSTRACT FROM AUTHOR]

[Display omitted] • First molecular dynamics simulation on ion transportation and ion emission of the external wetted electrospray. • The ion emission current increased with the net charge and the ion number of the meniscus. • How the emitter wettability, the electric field and the temperature influenced the electrospray had been investigated. • The asymmetric wetting behavior of the cation and the anion influenced the ion transportation and the ion emission. The micro processes of the external wetted electrospray were investigated using molecular dynamics simulations. It was found that the asymmetric wetting behavior of the ions plays an important role in affecting the ion transportation and ion emission of the electrospray when varying the operation parameters. Increasing the wettability of the emitter, the wetting force difference between the cations and the anions increases proportionally, whereas the emission current reached the highest current 77 nA at a moderate wettability with the L-J well-depth ε emitter = 0.6186 kcal/mol. Switching the electric field polarity to negative, hindered the ion transportation contributed by the wetting force difference and reduced the current by 39 %. Higher temperature (323 K) weakens the wetting force and the wetting force difference, thus increasing the emission current (83 nA) and emission of ion clusters with low charge to mass ratio. In addition, the higher electric field strength would lead to higher emission current, but an excessive electric field of 1 V/nm would lead to high plume divergence angle and unsteady ion emission. The present study provides useful information in controlling the emission characteristics of the external wetted electrospray and could promote its application in various fields. [ABSTRACT FROM AUTHOR]

Engaging communities through exhibits displayed at community-oriented events is a longstanding practice in community activism that could prove valuable for shifting individual and collective behavior toward measures that can help reduce climate change. In this investigation we examined the effect of a climate change community exhibit that focused on four environmental issues: switching to electric vehicles, switching to community solar for residential electricity needs, reducing meat consumption, and supporting forest conservation and reforestation efforts. Participants from the greater Boston area (N = 125) were surveyed before and after attending the exhibit. Attending the exhibit increased participants' perceptions of how many members in their community engaged in action for each issue and how morally right community members thought addressing the issue was. Further, increases in how confident participants felt in engaging in the relevant actions, as well as in ease of engagement were also observed. Participants also expressed increased interest (albeit inconsistently so) in, and likelihood of, engaging in action for each issue. Across all issues, exposure to the exhibit also increased whether engaging in action was rated as an effective way to reduce climate change. Implications and future directions for interventions utilizing climate change exhibits are discussed. • We evaluated the effectiveness of a community intervention fielded in Boston • The intervention targeted actions that can be taken to increase sustainability • The intervention was a portable visual exhibit displaying this information • Significant effects were noted relative to the pre-treatment phase • Descriptive and injunctive norms, proenvironmental attitudes and beliefs were increased [ABSTRACT FROM AUTHOR]

With the advent of the Internet of Things, nanoelectronic devices or memristors have been the subject of significant interest for use as new hardware security primitives. Among the several available memristors, BiFe O 3 (BFO)-based electroforming-free memristors have attracted considerable attention due to their excellent properties, such as long retention time, self-rectification, intrinsic stochasticity, and fast switching. They have been actively investigated for use in physical unclonable function (PUF) key storage modules, artificial synapses in neural networks, nonvolatile resistive switches, and reconfigurable logic applications. In this work, we present a physics-inspired 1D compact model of a BFO memristor to understand its implementation for such applications (mainly PUFs) and perform circuit simulations. The resistive switching based on electric field-driven vacancy migration and intrinsic stochastic behaviour of the BFO memristor are modelled using the cloud-in-a-cell scheme. The experimental current–voltage characteristics of the BFO memristor are successfully reproduced. The response of the BFO memristor to changes in electrical properties, environmental properties (such as temperature) and stress are analyzed and consistant with experimental results. [ABSTRACT FROM AUTHOR]

Nonlinear resistive field grading materials are widely used in the electrical and electronic applications, and are usually researched based on the initial nonlinear conductivity characteristics of synthetic materials. However, the long-term stability of these materials are rarely reported. In this paper, the effects of thermal ageing on nonlinear resistive field grading material and the electric field distribution of DC cone spacers are studied. The 30 wt.% SiC/epoxy micro-composites are prepared and are thermally aged at 180 °C for 1080 h. The infrared spectroscopy, dielectric properties, breakdown strength and nonlinear conductivity are measured, respectively. In addition, a simulation model for a cone spacer is built, and the electric field and power dissipation density are calculated. With the increasing thermal ageing time, the relative permittivity and loss tangent increase, and the breakdown strength decreases. Besides, the nonlinear coefficient of nonlinear conductivity almost increases, and the switching electric field of nonlinear conductivity decreases. Simulation results show that the aged micro-composites can homogenize the electric field in the cone spacer, but the thermal ageing causes the increase in power dissipation density and threatens the safe operation of the cone spacer. [ABSTRACT FROM AUTHOR]

Electrochromic nanomaterial membrane (ENM) Device is fabricated utilizing sputter technique on ITO glass substrates integrating with Ag NW-doped WO3 as electrochromic film, PEO as electrolyte and H+Nb2O5 as counter electrode that grab intensified concept in smart applications mostly as switchable displays. Optical analysis of the newly developed and fabricated ENM Nanosystem device is examined and compared with the existing and analogous nanostructured devices of the era. The ENM device is observed to possess a peak bleaching transmittance of 91% at 515 nm, which is ~ 8% enriched in visible spectrum in contrast to the existing nanomaterial membrane device. Transmittance modulation of ENM is calculated to be 76.6%. The faster switching of the ENM for electric dimming is observed to hold with 25, 33 and 30 s of increment at 500, 550 and 600 nm, respectively. Also the voltage variation for the ENM is analysed over − 2 V to + 2.5 V that provide a detailed and spacious changing across the full spectrum range. The cyclic voltammetry (CV) measurement on the entire Nanocomposite ENM Device revealed contraction of current density due to carrier confinement effect by coagulation of both EC and counter electrode membranes and thereby the quantifiable Formal Reduction Potential of the device is acquired owing to simultaneous ion confinement as well as carrier transition. The electrochemical response of the two electrodes on ITO-coated glass substrate as well as the entire nanocomposite-based membrane device entail the novel ENM device to be an excellent solution with appropriateness and superior efficiency for smart applications and approaches. [ABSTRACT FROM AUTHOR]

This paper proposes a dual-harmonic pole-changing (PC) motor with split permanent magnet (PM) poles (DHPCM-SPMPs). By adopting a split PM pole structure, the amplitude of the third PM flux density is increased greatly. Therefore, when a PC winding is adopted to couple with the fundamental and third PM flux density components, respectively, the proposed motor can work as a PC PM motor to satisfy operating demands of electric tractors. The design and effect of the proposed split PM pole structure is introduced first. The winding topology is then designed according to the slot vector diagrams of the two PM flux density components, and the PC operation can be realized by electric switches. Aiming at a torque ratio design objective, the PM structure parameters can be determined based on mathematical derivation, and the speed-widening capability is proved based on the operation characteristic analysis. Finally, the electromagnetic performance of the DHPCM-SPMPs is investigated and compared by finite element analysis, which shows the high torque capability in eight-pole mode and the wide speed range in twenty-four-pole mode benefiting from the PC operation. [ABSTRACT FROM AUTHOR]

With speeding up development of 5 G chips, high-efficient thermal structure and precise management of tremendous heat becomes a substantial challenge to the power-hungry electronics. Here, we demonstrate an interpenetrating architecture of electrocaloric polymer with highly thermally conductive pathways that achieves a 240% increase in the electrocaloric performance and a 300% enhancement in the thermal conductivity of the polymer. A scaled-up version of the device prototype for a single heat spot cooling of 5 G chip is fabricated utilizing this electrocaloric composite and electromagnetic actuation. The continuous three-dimensional (3-D) thermal conductive network embedded in the polymer acts as nucleation sites of the ordered dipoles under applied electric field, efficiently collects thermal energy at the hot-spots arising from field-driven dipolar entropy change, and opens up the high-speed conduction path of phonons. The synergy of two components, thus, tackles the challenge of sluggish heat dissipation of the electroactive polymers and their contact interfaces with low thermal conductivity, and more importantly, significantly reduces the electric energy for switching the dipolar states during the electrocaloric cycles, and increases the manipulable entropy at the low fields. Such a feasible solution is inevitable to the precisely fixed-point thermal management of next-generation smart microelectronic devices. Efficient thermal structure and precise heat management become a substantial challenge for electronics. Here, authors utilize the synergistic effect of classic heat transfer and electrocaloric cooling for fixed-point thermal management of chips. [ABSTRACT FROM AUTHOR]

Automotive industry is switching to Electric Vehicles (EV) to reduce CO emission. Environmental effects due to air pollution and strict 2 government norms on emission are determining the future of automobiles in India. A significant part in electric vehicle is battery packs. Nowadays battery pack manufacturers face difficulties to improve the efficiency of battery pack for its long-term usage, store energy for large amount of time and to improve the mileage of the electric vehicles. The individual cells are combined together in series or parallel connection to form module and those modules are combined together to form Battery Pack. These individual batteries are connected by means of interconnecting plate through suitable welding method. This paper discusses about the need for automotive market to switch to EV technology, trends of EV, current challenges faced by automotive industry, potential benefits of using EV, various challenges faced while manufacturing the battery pack and finally recommends the joining method of battery and interconnector plate by comparative study and assessment based on quality, cost and delivery. [ABSTRACT FROM AUTHOR]

Electrical manipulation of spins is essential to design state-of-the-art spintronic devices and commonly relies on the spin current injected from a second heavy-metal material. The fact that chiral antiferromagnets produce spin current inspires us to explore the magnetization switching of chiral spins using self-generated spin torque. Here, we demonstrate the electric switching of noncollinear antiferromagnetic state in Mn3Sn by observing a crossover from conventional spin-orbit torque to the self-generated spin torque when increasing the MgO thickness in Ta/MgO/Mn3Sn polycrystalline films. The spin current injection from the Ta layer can be controlled and even blocked by varying the MgO thickness, but the switching sustains even at a large MgO thickness. Furthermore, the switching polarity reverses when the MgO thickness exceeds around 3 nm, which cannot be explained by the spin-orbit torque scenario due to spin current injection from the Ta layer. Evident current-induced switching is also observed in MgO/Mn3Sn and Ti/Mn3Sn bilayers, where external injection of spin Hall current to Mn3Sn is negligible. The inter-grain spin-transfer torque induced by spin-polarized current explains the experimental observations. Our findings provide an alternative pathway for electrical manipulation of non-collinear antiferromagnetic state without resorting to the conventional bilayer structure. Under an applied current, chiral antiferromagnets, such as Mn3Sn, can produce a spin-polarized current. Here, by varying the thickness of a buffering layer, the authors show that this spin-polarized current can drive self-induced switching in polycrystalline Mn3Sn. [ABSTRACT FROM AUTHOR]

Ferroelectrics (FEs) are increasingly used in nonvolatile memory applications. However, the impact of the electric dipole switching on its material parameters, in particular on the dielectric response, is not fully understood. In this work, an analytical model, linking the dielectric response to the potential energy curve, is first used to qualitatively illustrate the nonconstant evolution of the dielectric response with applied electric field. Increasing precision, we then show from first-principles density functional theory simulations that defect-free FE materials undergo changes in potential energy near the FE switching that lead to vibrational modes softening, which impacts the dielectric response. In particular, we observe that the dielectric response $\varepsilon $ of an FE material with antialigned polarization increases as the applied electric field increases toward the coercive field. We incorporate this new insight in the time-dependent NLS-based predictions and demonstrate that this evolution of the dielectric response right before polarization reversal is required for a proper match between experiment and prediction of the capacitance–voltage (CV) characteristics of the metal–ferroelectric–metal (MFM) capacitor. [ABSTRACT FROM AUTHOR]

In this paper, a frequency switchable antenna design using genetic algorithms (GAs) for dual band WiMAX (3.5GHz) and WLAN (5.2GHz) applications is proposed. The area of the radiating patch element is divided into 2 mm square cells, with each cell assigned a conducting or non-conducting characteristic. To realize frequency reconfiguration, switches are incorporated into appropriate locations to activate/deactivate corresponding cells. The on/off states of the switches are represented by the presence or absence of conductor, respectively. Hence, the proposed approach allows the antenna to operate as mono-band or dual-band radiator according to the desired application. Further, measurements and simulations are carried out and a reasonable agreement is achieved. [ABSTRACT FROM AUTHOR]

Among different types of Non-Conventional Energy Sources, Solar Power has become highly prominent with exhausting suitable to innovation in Power Electronic Systems. The primary intention of the advised performance must limit the number of switches to enhance the output waveforms with a preferred harmonic profile. This topology moderates the estimate about switches, isolated DC origin, expenditure, and intensity of the circuit substantially as correlated to other topologies. The proposed method uses the MPPT approach to exploit the maximum energy from solar photovoltaic to load entirely. The Proposed method provides almost sinusoidal output waveforms by developing a few power switches. The SPV arrangement was simulated and constitution through SPV arrays, a DC-DC buck converter, and a sliding mode MPPT regulation. Based on the cascaded H-Bridge multilevel converters, The strong constraint enforced confined DC voltage sources considering separately Cascaded H-Bridge. This constitution converter worth along with diminishing the constancy based on the system. The system gives boosting voltages with improves the harmonic profile. Performance of the arrangement demonstrated in MATLAB SIMULINK as well as PROTEUS. [ABSTRACT FROM AUTHOR]

Read operation induced disturbance in SET-state in a tungsten oxide resistive switching memory is investigated. We observe that the reduction of oxygen vacancy density during read-disturb follows power-law dependence on cumulative read-disturb time. Our study shows that the SET-state readdisturb immunity progressively degrades by orders of magnitude as SET/RESET cycle number increases. To explore the cause of the read-disturb degradation, we perform a constant voltage stress to emulate high-field stress effects in SET/RESET cycling. We find that the read-disturb failure time degradation is attributed to high-field stress-generated oxide traps. Since the stressgenerated traps may substitute for some of oxygen vacancies in forming conductive percolation paths in a switching dielectric, a stressed cell has a reduced oxygen vacancy density in SET-state, which in turn results in a shorter read-disturb failure time. We develop an analytical read-disturb degradation model including both cycling induced oxide trap creation and read-disturb induced oxygen vacancy reduction. Our model can well reproduce the measured read-disturb failure time degradation in a cycled cell without using fitting parameters. [ABSTRACT FROM AUTHOR]

During the past decades, scientists have developed different kinds of nanorobots based on various driving principles to realize controlled manipulation of them for potential applications like medical diagnosis and directed cargo delivery. In order to design a nanorobot with advantages of simple operation and precise control that can enrich the family of intelligent nanorobots, an encoding manipulation method is proposed to control the movement of a DNA‐nanoparticle assembled nanorobot by combing electrophoresis and electroosmosis effect in independently charged array nanopores. The nanorobot is composed of one nanoparticle and one or two ssDNAs. ssDNAs act as the legs of the nanorobot. The selective ion transport through charged nanopores can induce cooperation and competition between the electroosmosis and electrophoresis, which is the main power to activate the nanorobot. Thus by simply switching the applied electric field and surface charge density of each nanopore which is defined as the encoded nanopore according to a predetermined strategy, the well‐controlled encoding manipulation including capturing, releasing, jumping, and crawling of the nanorobot is realized in this work. The study is expected to realize its value in many interesting applications like drug delivery, nanosurgery, and so on in the near future. [ABSTRACT FROM AUTHOR]

Artificially-structured functional materials (AFMs) are artificial media that combine the advantages of nature materials and artificial structures to produce excellent and unexpected properties. Ferroelectric materials have key features in possessing spontaneous polarizations, which can be switched by using electric field, temperature, and strain. This review article attempts to provide a comprehensive insight into the current development of ferroelectric composite AFMs, and to introduce a developing subject in realizing multifield controls for tunable functional devices. Some typical ferroelectric materials and their multifield tunable mechanisms are summarized in detail. The incorporation of ferroelectric materials can yield various designs of AFMs to modulate electromagnetic waves. Recent progress of typical designs with different tuning strategies for active AFMs are illustrated and compared, including the metamaterials, metasurfaces, heterojunctions, superlattices, and their hybrid designs. This scientific subject involves interesting research topics of electromagnetism, electronics, optoelectronics, and ferroelectrics, which is significant to bring novel functionalities via multifield controls. [ABSTRACT FROM AUTHOR]

Nonvolatile resistive switching is one of the key phenomena for emerging applications in optoelectronics and neuromorphic computing. In most of the cases, an electric field is applied to a two terminal dielectric material device and leads to the formation of a low resistance filament due to ion migration. However, the stochastic nature of the ion migration can be an impediment for the device robustness and controllability, with uncontrolled variations of high and low resistance states or threshold voltages. Here, we report an optically induced resistive switching based on a CdS/V3O5 heterostructure which can overcome this issue. V3O5 is known to have a second order insulator to metal transition around Tc ≈ 415 K, with an electrically induced threshold switching at room temperature. Upon illumination, the direct transfer of the photoinduced carriers from the CdS into V3O5 produces a nonvolatile resistive switching at room temperature. The initial high resistance can be recovered by reaching the high temperature metallic phase, i.e., temperatures above Tc. Interestingly, this resistive switching becomes volatile around the Tc. By locally manipulating the volatile and nonvolatile resistive switching using electric field and light, this system is a promising platform for hardware based neuromorphic computing implementations. [ABSTRACT FROM AUTHOR]

Nonvolatile resistive switching is one of the key phenomena for emerging applications in optoelectronics and neuromorphic computing. In most of the cases, an electric field is applied to a two terminal dielectric material device and leads to the formation of a low resistance filament due to ion migration. However, the stochastic nature of the ion migration can be an impediment for the device robustness and controllability, with uncontrolled variations of high and low resistance states or threshold voltages. Here, we report an optically induced resistive switching based on a CdS/V3O5 heterostructure which can overcome this issue. V3O5 is known to have a second order insulator to metal transition around Tc ≈ 415 K, with an electrically induced threshold switching at room temperature. Upon illumination, the direct transfer of the photoinduced carriers from the CdS into V3O5 produces a nonvolatile resistive switching at room temperature. The initial high resistance can be recovered by reaching the high temperature metallic phase, i.e., temperatures above Tc. Interestingly, this resistive switching becomes volatile around the Tc. By locally manipulating the volatile and nonvolatile resistive switching using electric field and light, this system is a promising platform for hardware based neuromorphic computing implementations. [ABSTRACT FROM AUTHOR]

Second-order optical nonlinearity is the essential concept for realizing modern technologies of optical wavelength conversion. The emerging helical polarization fluid, dubbed helielectric nematic, now makes it possible to design and easily fabricate various polarization structures and control their optical responses. The matter family is demonstrated as an ideal liquid platform for nonlinear optical conversion and amplification with electricreconfigurable tunability. We here develop a universal phase matching theory and reveal a nonclassic chirality-sensitive phase-matching condition in the polarization helices through both the numerical calculation and the experimental validations. The nonlinear optical amplification can be dramatically modulated with a contrast ratio of >100:1 by an in-plane electric field. Furthermore, we employ the director relaxation under electric fields coupled with nonlinear optical simulation to clarify the topology-light interactions. [ABSTRACT FROM AUTHOR]

Nanostructured Au films fabricated by the assembling of nanoparticles produced in the gas phase have shown properties suitable for neuromorphic computing applications: they are characterized by a non-linear and non-local electrical behavior, featuring switches of the electric resistance whose activation is typically triggered by an applied voltage over a certain threshold. These systems can be considered as complex networks of metallic nanojunctions where thermal effects at the nanoscale cause the continuous rearrangement of regions with low and high electrical resistance. In order to gain a deeper understanding of the electrical properties of this nano granular system, we developed a model based on a large three dimensional regular resistor network with non-linear conduction mechanisms and stochastic updates of conductances. Remarkably, by increasing enough the number of nodes in the network, the features experimentally observed in the electrical conduction properties of nanostructured gold films are qualitatively reproduced in the dynamical behavior of the system. In the activated non-linear conduction regime, our model reproduces also the growing trend, as a function of the subsystem size, of quantities like Mutual and Integrated Information, which have been extracted from the experimental resistance series data via an information theoretic analysis. This indicates that nanostructured Au films (and our model) possess a certain degree of activated interconnection among different areas which, in principle, could be exploited for neuromorphic computing applications. [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) may constitute the most disruptive and innovative product since the smartphone. Further, there seems to be a relationship between the percentage of women in congress and plug-in vehicles sold in 2021. This study considers the relation between the country with the least number of women in congress and the least EVs sold—the State of Kuwait. This study asks 234 women drivers in Kuwait what policy-level changes would make them switch from conventional Internal Combustion Engine cars (ICE) to EVs. The results showed the following: More than 50% of participants would buy EVs within the next three years if several conditions were met: lower purchase price with government assistance and availability of suitable infrastructure for EVs such as wide availability of fast charging stations, fast lanes, and free parking spaces. More than 40% of participants would start thinking seriously about buying EVs if gas/fuel prices increased by 50–199%; they also thought EVs were safer regarding fire and car crashes. They would pay 6–20% more for EVs that are environmentally friendly and faster than gasoline cars. About 40% of women drivers would be able to charge EVs in their residential areas in Kuwait, but the lack of charging stations remains the biggest obstacle to the mass adoption of EVs. This study also made various suggestions to overcome barriers to EV introduction in Kuwait, such as the increase of fast charging stations, as well as marketing strategies and government initiatives and policies. One key implication is that focused educational efforts are needed to help women owners in Kuwait better understand the benefits and overall potential of EVs. [ABSTRACT FROM AUTHOR]

Laser particles providing bright, spectrally narrowband emission renders them suitable for use as cellular barcodes. Here, we demonstrate a microfluidic platform integrated with a high-speed spectrometer, capable of reading the emission from laser particles in fluidic channels and routing cells based on their optical barcodes. The sub-nanometer spectral emission of each laser particle enables us to distinguish individual cells labeled with hundreds of different laser colors in the near infrared. Furthermore, cells tagged with laser particles are sorted based on their spectral barcodes at a kilohertz rate by using a real-time field programmable gate array and 2-way electric field switch. We demonstrate several different flavors of sorting, including isolation of barcoded cells, and cells tagged with a specific laser color. We term this novel sorting technique laser particle activated cell sorting (LACS). This flow reading and sorting technology adds to the arsenal of single-cell analysis tools using laser particles. [ABSTRACT FROM AUTHOR]

Magnetoelectric multiferroic materials can exhibit a variety of functional properties such as electric field control of magnetization and nonreciprocal electromagnetic responses. Such a magnetoelectric response may be further enriched by the combination of the magnetoelectric order and a peculiar crystallographic order, such as crystal chirality. Recently, it was reported that a chiral‐lattice magnet Pb(TiO)Cu4(PO4)4 showing a magnetoelectric quadrupole order in its ground state exhibits anomalous chirality‐induced tilt of magnetization vector with respect to an applied magnetic field. In this progress report, additional results that advance the understanding of chirality‐induced tilt of magnetization vector are presented. It is found that chirality‐induced tilt of the magnetization vector also exists in a magnetic‐field‐induced ferroelectric (FI‐FE) phase of this compound that is stabilized in magnetic fields higher than 16 tesla. The resulting transverse component of the magnetization can be switched with an applied electric field through a polarization reversal. The analysis indicates that this transverse component is as large as ≈0.014 μB per f.u, suggesting that the tilting angle of the magnetization in the FI‐FE phase is much larger than that in the low‐field phase. Also, as another research progress, electric field control of nonreciprocal directional dichroism in the FI‐FE phase is demonstrated. [ABSTRACT FROM AUTHOR]

• The force-electric response of PZT-5H under different impact loads was investigated. • A theoretical model of impact depolarization of PZT-5H was developed using electric domain switching as a bridge between mechanical response and depolarization behavior. • The model established through experiments and theoretical descriptions can reflect the depolarization law under the impact. In order to establish the relationship between the load and depolarized charge under stress waves, we established the stress depolarization experimental platform and obtained the time history curve of charge variation with the load. Then, we built a theoretical model of PZT-5H impact depolarization and physically described the model based on the characteristics of the experimental data and domain switching. Meanwhile, we obtained the uncertain parameters in the model by using the CBP neural network and the genetic algorithm. Finally, the effectiveness of the impact depolarization theory model was verified by comparing it with experimental values. The results indicated that the established PZT impact depolarization model can reflect the depolarization law of materials in the range of 0 ∼ 250 MPa stress waves. It provided a predictive method for the application of piezoelectric materials in extreme engineering such as contact fuses, pulse power supplies, and impact sensors. [ABSTRACT FROM AUTHOR]

Quenching from high temperatures has been identified as a useful means to enhance the piezoelectric properties and thermal stability of bismuth-based perovskite ferroelectrics. In the present work, it is demonstrated that quenching leads to improvement of depolarization temperature, ferroelectric and piezoelectric properties in Na 0.5 Bi 0.5 TiO 3 -NaNbO 3 (NBT-0.1NN) ceramics. In-situ synchrotron x-ray diffraction measurements indicated an irreversible transformation from cubic to coexisting cubic and rhombohedral phases during the application of a high electric field, for both as-sintered and quenched ceramics. These results confirm the non-ergodic relaxor ferroelectric nature of the materials. DC poling induced a transformation to single-phase rhombohedral structure in both cases, with highly textured domain configurations. These well-oriented ferroelectric domain states were relatively stable under subsequent bipolar electric field cycling. For the pre-poled NBT-0.1NN ceramics, the quenched samples were found to exhibit the highest intrinsic (lattice strain) and extrinsic (domain switching) contributions to electrostrain, due to the increased rhombohedral distortion. • High energy x-ray diffraction is used to analyse the structure of NBT-NN ceramics. • Coexisting cubic and rhombohedral phases are induced by an applied electric field. • Quenched samples have more rhombohedral phase and enhanced ferroelectricity. • DC poling results in transformation to a highly textured single rhombohedral phase. • Electrostrain is dominated by the intrinsic lattice strain mechanism. [ABSTRACT FROM AUTHOR]

The toroidal dipole is a localized electromagnetic excitation induced by a reversely distributed circulating current. The magnetic fields with opposite directions are connected end to end to form a closed circular magnetic field, and a toroidal dipole with non-radiative electric field characteristics is obtained. However, active manipulation of the toroidal resonance has remained largely unexplored due to the scarcity of compact tunable elements so far. Here, we propose a planar terahertz metamaterial composed of an asymmetric metallic double splits ring resonator, which can excite a toroidal dipole resonance. To active control the toroidal dipole resonance, the monolayer graphene is integrated with the metamaterial. By changing Fermi energy of graphene, the transmission amplitude of the toroidal dipole resonance is actively modulated and finally switched into a electric resonance or magnetic resonance. Therefore, switching between the non-radiation and the high-radiation, as well as active modulation of the toroidal dipole have potential application prospects in the design of filters, high-sensitivity sensors, and modulators. [ABSTRACT FROM AUTHOR]

Phase retrieval is a generic calculating phase method through intensity images and prior conditions. Usually, the image recording system requires stable mechanical movement and accurate alignment between different phase-shift images, which greatly limits the imaging speed and stability, resulting in mismatch or low phase retrieval quality. In this work, we propose a single-shot polarization-sensitive phase retrieval developed from triple transport of the intensity method with anisotropic metasurface. By applying gradient phase along the interface, three images with diffractive phase differences are projected on the recording plane. The three images are formed with known diffraction distances due to the conjugate Pancharatnam−Berry phase modulation of metasurface. The recorded images are calculated and post-processed using transport of intensity equation technique to obtain the phase of object. As a proof-of-principle, we demonstrate the phase imaging results through measuring phase-only objects with single-shot capture. Compared to traditional transport-of-intensity equation optical systems, our method requires no mechanical or system tuning, and polarization or electric controller switching. Thus, it can acquire three differently focused images with single-shot. This significantly improves the time efficiency of the experiments. Such compact metadevice with simplified manipulation and easy post-processing for phase retrieval can be applied to various applications, such as optical microscopy, fluid measurement, and on-ship integration. [ABSTRACT FROM AUTHOR]

Inverter circuits play an important role in providing energy to multiple loads or energy lines. In cases where power lines or loads are unbalanced, it is important to balance and regulate the power it carries. Therefore, in this study, an inverter structure with an inverted connecting double dc-dc converter is used to drive unbalanced loads. While load balancing is performed by changing the widths of the pulse width modulation that make up the voltage in load balancing methods in other inverter studies, the maximum point of the generated voltage is changed by affecting the operating times of the converters in this study. First, the circuit structure and the working order of the circuit are given. Then three-phase balanced and unbalanced loads are driven. The unbalanced loads driven are finally balanced with the proposed circuit structure. Distortions of load currents are decreased as %3, 51. This distortion value is lower than 4% reported by the international IEEE, while the obtained load currents maintain a smooth sinusoidal structure. [ABSTRACT FROM AUTHOR]