High Field Effect Research Articles

A novel flexural damping channel magnetorheological damper with high effective magnetic field coverage and experimental verification of damping performance

Abstract Conventional magnetorheological dampers (MRDs) have limitations owing to their low effective magnetic field coverage, and improving MRD structures is a common approach to address this issue. However, many existing MRD designs have limitations such as large radial dimensions and high coil power consumption. Therefore, this paper transformed the conventional damping channel into the flexural damping channel to increase the effective magnetic field coverage of the MRD based on the conventionalstructure. And then, the pressure drop model was utilized to preliminarily determine the structural parameters of the new MRD. Subsequently, a multi-physics coupling finite element method (FEM) analysis model was constructed to accurately determine the structural parameters, ensuring that the novel flexural damping channel (NFDC) MRD increases the output peak damping force while reducing the radial dimension and input power. Furthermore, the damping force variable range is stabilized when the excitation current is zero (field-off). Finally, a large number of vibration tests were conducted on both the conventional and NFDC MRDs, and it was found that the NFDC MRD has better vibration energy dissipation capacity and higher output peak damping force while maintaining a basically same field-off damping force variable range compared with the conventional MRD. The above process not only proved that the NFDC MRD possesses excellent output damping capability and working condition adaptability, but also validated the operational effectiveness of employing the multi-physics coupling analysis method to design the NFDC MRD.

Effect of high magnetic field annealing on microstructure, texture, and properties of high-strength non-oriented silicon steels

The challenge in high-strength non-oriented silicon steel is the synergistic enhancement of both strength and magnetic properties, which are both significantly influenced by microstructure and texture of the steel. To address this, a novel high magnetic field annealing was employed to modify the microstructure and texture of the steel, aiming for a concurrently optimization of these properties. The results indicated that both the iron loss and strength decreased with increasing annealing temperature, whereas the magnetic induction intensity increased firstly and then decreased. The application of a high magnetic field meaningfully enhanced the magnetic properties of non-oriented silicon steel, whereas the strength of the steel was significantly decrease at 750 °C, but this decrease was reduced at higher temperature. The application of magnetic field reduced the Gibbs free energy of the system during the recrystallization process resulting in a facilitation of recrystallization. During low-temperature annealing (750-800 °C) in the high magnetic field, the dislocation density decreased, and internal stress was reduced, leading to a significant reduction in hysteresis loss and an improvement in magnetic properties. However, the reduction in dislocation density resulted in a substantial deterioration of strength at low temperature. With increasing annealing temperature, the enhanced grain growth with the application of magnetic field lead to an increase in magnetic induction intensity, whereas the grain boundary strengthening contribution decreased, resulting in a decrease in strength. Furthermore, the optimal comprehensive properties were achieved by annealing at 850 °C with a high magnetic field, which yielded a magnetic induction intensity B5000 of 1.679 T, a high-frequency iron loss P1.0/400 of 21.44 W/Kg, and a yield strength of 508 MPa, are well-suited for utilization in the drive motors of new energy vehicles.

Investigating the Effects of High Magnetic Fields on the Phase Stability of Tl2Ba2Ca2Cu3O10-δ Superconductor

Investigating the Effects of High Magnetic Fields on the Phase Stability of Tl2Ba2Ca2Cu3O10-δ Superconductor

Enhancing second harmonic generation in lithium niobate metasurfaces through symmetric protection bound states in the continuum

In order to address the issue of high loss and low field effect in the generation process of traditional second harmonic, we employ lithium niobate (LN), a highly efficient nonlinear material. Our designed structure exhibits a symmetry-protected bound state in a continuum medium (BIC) when subjected to a y-polarized incident wave, resulting in an impressive second-harmonic conversion efficiency of 5.5 % at a pump strength of 0.4MW/cm2. Moreover, it also shows accidental BIC when subjected to an x-polarized incident wave, exhibiting a second harmonic conversion efficiency of 1.83 %. We conducted a Cartesian multipole analysis to investigate the underlying cause of BIC formation, and the results are in excellent agreement with the electromagnetic field map. Subsequently, we explored the correlation between asymmetry degree, Q value, and second harmonic conversion efficiency. Our study presents novel approaches for enhancing symmetry-protected BICs in second harmonic waves while providing simplified indicators for evaluating second harmonic transformation efficiency.

Combined effects of high hydrostatic pressure and pulsed electric fields on quinoa starch: Analysis of microstructure, morphology, thermal, and pasting properties

The aim of this study was to evaluate the impact of non-thermal methods, using high hydrostatic pressure (HHP) and pulsed electric field (PEF), on the dual modification of quinoa starch and to analyze the microstructural, morphological, thermal, pasting, and texture properties. Starch was treated with HHP at 400 MPa for 10 min, while PEF was applied using voltages of 10 and 30 kV cm−1 for a total time of 90s. The modification techniques were effective in breaking down amylose molecules and amylopectin branches, where for the dual treatment, higher values of DP6–12 were found. The average diameter and gelatinization temperatures were elevated after HHP, thus forming clusters that require more energy for paste formation. The use of 30 kV cm−1 and 400 MPa (HP30) in starch facilitates the creation of new food products with better texture, stability and nutritional value, making them suitable for use in food emulsions and the cosmetics industry.

Thermally-assisted magnetization of magnetic composites for enhanced micro actuator performance: a low-cost approach using permanent magnets

A micro actuator based on magnetic composite materials can control its deformation and movement through varying magnetic fields, showcasing significant applications in fields such as soft robotics and biomedicine. However, existing magnetic composite materials still require complex magnetization processes involving sophisticated equipment and demanding external magnetic fields. This paper proposed a low-cost, thermally-assisted magnetization process based on permanent magnets. It was observed that the maximum magnetic induction intensity on the surface of magnetic composites is linearly correlated with the heating temperature. Additionally, magnetically treated materials at elevated temperatures can achieve traditional high-field magnetization effects at lower field strengths. Specifically, we synthesized a magnetic composite with 50%wt NdFeB@PDMS and investigated the conditions of the thermally-assisted magnetization process based on permanent magnets, along with mechanical and magnetic performance characterization methods. Experimental results indicate that below 200 °C, the tensile strength and elastic modulus of the base material increase with rising temperatures, demonstrating a trend of high-temperature hardening. However, when the temperature exceeds 200 °C, the elevated temperature leads to the decomposition of the base material, resulting in a rapid decrease in the tensile strength and elastic modulus of the magnetic composite. Furthermore, high temperatures can disrupt the magnetic domains of the magnetic material, reducing its coercive force and making it more susceptible to external magnetic fields and heat, thereby compromising the stability of the magnetic material. These findings provide new insights into the development of more stable and controllable magnetic composite materials.

Effects of different pretreatment on the drying characteristics and pectin properties of jujube by microwave coupled with pulsed vacuum drying

AbstractThe effects of ultrasound (US), ultrahigh pressure (UP), cold plasma (CP), and high pressure and pulsed electric fields (PEF) pretreatments were evaluated for drying characteristics, bioactive components, and pectin properties of jujube slices during microwave coupled with pulsed vacuum drying (MPVD). US, CP, and PEF reduced drying time by 18.75%, while UP reduced it by 6.25%. Samples treated with US and PEF showed improved color and rehydration (345.11%, 319.24%), with SEM revealing larger pores post‐pretreatment. PEF‐treated jujube had highest phenol (16.95 mg GAE/g DW) and water‐soluble pectin(WSP) (43.71 mg/g AIR), correlating positively with rehydration (r = 0.67). CP had highest flavonoid content (17.01 mg RE/g DW) and US showed highest antioxidant activity (DPPH 80.57%, ABTS 89.65%). Chelate‐soluble pectin (CSP) Sodium carbonate‐soluble pectin (NSP) was positively correlated with hardness (r = 0.71, 0.69). These findings suggest pretreatments improve drying efficiency, nutrient retention, and pectin functionality in jujube products. Practical ApplicationsDrying for jujube (Ziziphus jujuba Mill.) is the most common method of processing and ensure the sale. Three kinds of non‐thermal processing pretreatment method (ultrasound, ultrahigh pressure, and cold plasma) combined with novel drying method, microwave coupled pulsed vacuum drying (MPVD) was studied in the application on the dehydration of jujube slice in this paper. The drying characteristics and pectin properties of winter jujube were analyzed and treated by MPVD compared with freeze drying and hot air drying, for both technological research and processing practice. The drying kinetics, bioactive compounds, antioxidant capacity, sensory attributes, and pectin properties were also used as descriptors in order to promising dehydration method for obtaining high value‐added jujube products. Moreover, the relationship between the cell wall pectin and the phenols, hardness and crispness were analyzed, which give a new insight to study the changing scheme in the nutrients and the texture during the dehydration for fruits and vegetables.

High-mobility and high-reliability Zn-incorporated amorphous In2O3-based thin-film transistors

Polycrystalline indium oxide-based thin film transistors (In2O3 TFTs) have attracted considerable attention because of high field effect mobility (μ FE ∼ 100 cm2 V−1 s−1). However, In2O3 TFTs exhibit poor reliability owing to the adsorption and/or desorption of gas molecules at the grain boundaries. The incorporation of Zn suppresses the crystallization of In2O3. Herein, we systematically studied the effect of Zn incorporation into In2O3 TFTs. The crystallization of In2O3 was suppressed when the Zn concentration ranged from 25% to 68%. Amorphous InZnO (IZO) TFTs with 25% Zn exhibited the highest μ FE of 41 cm2 V−1 s−1 and excellent reliability. In contrast, polycrystalline IZO TFTs showed a low μ FE <12 cm2 V−1 s−1 due to the formation of grain boundaries, and poor reliability after positive gate bias, mostly due to electron trapping at the polycrystalline/insulator interface. These results render an approach to realize In2O3 TFTs that show reasonably high μ FE and excellent reliability.

Performance improvement of planar silicon nanowire field effect transistors via catalyst atom doping control

Catalytic growth of silicon nanowires (SiNWs), mediated by metallic droplet, provide ideal quasi-1D channels to construct high performance field effect transistor (FET). However, the incorporation of catalytic metal atoms into SiNWs channels has significant impact on the FET characteristics, and thus needs to be better understood and controlled to fulfil its potential for high performance electronics. In this work, we focus on the effect of the incorporation of indium (In) catalytic atoms into planar SiNWs, grown via an in-plane solid-liquid-solid (IPSLS) mechanism, on the FET device performance. It is found that the initial high concentration of p-type In dopants in the as-grown SiNWs led to an equivalent boron (B) doping of 5×1018 cm−3. However, a simple step-wise annealing in oxygen at different temperatures, varied from 620 °C to 920 °C, can help to out-diffuse the dissolved In atoms into the surface SiO2 layer, and reduce the In concentrations down to <5×1017 cm−3, as verified by atom-probe tomography (APT) and four-point-probe measurements. This effective dopant control enables a remarkable device performance improvement of the Schottky barrier FETs, built upon an orderly array of parallel SiNWs of approximately 25 nm in diameter, where the current ratio (Ion/Ioff) has been substantially boosted from 105 to 108, while the subthreshold swing (SS) reduced from 400 mV/dec down to ∼100 mV/dec, with a hole carrier mobility increased from 10 to ∼75 cm2 V−1 s−1 as extracted according to a finite element analysis. These results pave the way for the employment of the catalytic IPSLS SiNWs to serve as high quality 1D channels for high-performance SiNWs-based electronics and sensors.

Effect of high static electric field on germination and early stage of growth of Avena sativa and Raphanus sativus

Presented study investigated the impact of a stationary electric field with an average value of 185 kV/m on the germination process and early growth of radish (Raphanus sativus – a eudicot plant) and oat (Avena sativa – a monocot plant). Electric field stimulation may prove to be one method to sustainably increase crop efficiency. The research is aimed to increase knowledge of the effect of a static electric field on the plant growth process, because understanding of the topic is still limited. The plants were grown on a viscose substrate in a dark room without any light. Studies have shown that the electric field can affect the germination and growth process depending on the plant species. The findings indicate a positive influence of the electric field on radish germination. The presence of the electric field accelerates the germination process and growth of young plants. On the first day of germination (the 3rd day of cultivation), about 3.2 times as many plants germinated in the samples exposed to a stationary electric field compared to the control samples. On the last day of the experiment (the 8th day of cultivation), the tallest plants in the samples subjected to the electric field were 8 % higher, compared to the tallest plants in the control samples. On the other hand, the results demonstrate a negative impact of the electric field on oat seed germination. The presence of an electric field delays the germination process and reduces the number of germinated seeds. On the last day of the experiment (the 11th day of cultivation), about 1.25 times fewer oat plants germinated in the samples exposed to a stationary electric field compared to the control samples. The tallest plants in the samples subjected to the electric field were 1.1 times smaller than the tallest plants in the control samples.

High magnetic field effects on the phase separation behaviour of Fe-15mass%Cu alloys probed by 57Fe Mössbauer spectroscopy

High magnetic field effects on the phase separation behaviour of Fe-15mass%Cu alloys probed by 57Fe Mössbauer spectroscopy

P‐13: Excessive Oxygen induced Threshold Voltage Shifts in High Mobility Top‐Gate PrIZO TFTs

The top gate self‐alignment (TGSA) Praseodymium‐doped indium zinc oxide (PrIZO) thin film transistor (TFT) was fabricated with different process condition in our production line, and high field effect mobility of 40.83 cm2 V‐1 s‐1 was obtained by regulating the GI and ILD parameters. At the same time, the devices show excellent stability with PBTS of 0.52 V and NBTIS of ‐0.9 V, indicating its potential in overcoming the trade‐off between mobility and reliability.

High mobility graphene field effect transistors on flexible EVA/PET foils

Monolayer graphene is a promising material for a wide range of applications, including sensors, optoelectronics, antennas, EMR shielding, flexible electronics, and conducting electrodes. Chemical vapor deposition (CVD) of carbon atoms on a metal catalyst is the most scalable and cost-efficient method for synthesizing high-quality, large-area monolayer graphene. The usual method of transferring the CVD graphene from the catalyst to a target substrate involves a polymer carrier which is dissolved after the transfer process is completed. Due to often unavoidable damage to graphene, as well as contamination and residues, carrier mobilities are typically 1000–3000 cm2(Vs)−1 , unless complex and elaborate measures are taken. Here, we report on a simple scalable fabrication method for flexible graphene field-effect transistors that eliminates the polymer interim carrier, by laminating the graphene directly onto office lamination foils, removing the catalyst, and depositing Parylene N as a gate dielectric and encapsulation layer. The fabricated transistors show field- and Hall-effect mobilities of 7000–10 000 cm2(Vs)−1 with a residual charge-carrier density of 2×1011 1 cm−2 at room temperature. We further validate the material quality by terahertz time-domain spectroscopy and observation of the quantum Hall effect at low temperatures in a moderate magnetic field of ∼5 T. The Parylene encapsulation provides long-term stability and protection against additional lithography steps, enabling vertical device integration in multilayer electronics on a flexible platform.

High-voltage electrostatic field with 35 kV-15 min could reduce Pseudomonas spp. to maintain the quality of pork during −1 °C storage

This study evaluated the bacterial-reducing effects of different high voltage electrostatic field (HVEF) parameters (voltage 20,25,30,35 kV, time 5,10,15,20 min) on chilled pork, and studied the effects of HVEF bacterial-reducing treatment on the microbial number and the quality of pork during ice-temperature (−1 °C) storage. The results showed that HVEF of 35 kV-15 min was the best parameter, which made a 0.51 log CFU/g bacterial reduction. HVEF treatment reduced the number of Pseudomonas spp. by 0.50 log CFU/g, but no significant decrease was found in Brochothrix thermosphacta and lactobacilli. The abundance of Pseudomonas fragi (most abundant species in pork) significantly decreased after HVEF treatment, which may be the reason for the significant decrease of TVB-N and TBARS in HVEF group at the end of storage. During −1 °C storage, HVEF group exhibited better quality characteristics on shear force and cooking loss, which could effectively extend the shelf-life of chilled pork. Industrial relevanceHigh voltage electrostatic field (HVEF) is an emerging non-thermal inactivation technology. However, it is necessary to optimize the processing parameters based on the characteristics of the food. This study optimized the optimal processing parameters of HVEF for chilled pork and validated its contribution to maintaining the quality of pork during ice-temperature storage. These findings are of great significance for food processing, food preservation and the development of new refrigeration equipment.

Effects of high voltage pulsed electric field on structural properties and immune reactivity of arginine kinase in Fenneropenaeus chinensis

To evaluate the effect of high voltage pulsed electric field (PEF) treatment (10–20 kV/cm, 5–15 min) on the structural characteristics and sensitization of crude extracts of arginine kinase from Fenneropenaeus chinensis. By simulated in vitro gastric juice digestion (SGF), intestinal juice digestion (SIF) and enzyme-linked immunosorbent assay (ELISA), AK sensitization was reduced by 42.5% when treated for 10 min at an electric field intensity of 15 kV/cm. After PEF treatment, the α-helix content decreased, and the α-helix content gradually changed to β-sheet and β-turn. Compared to the untreated group, the surface hydrophobicity increased and the sulfhydryl content decreased. SEM and AFM analyses showed that the treated sample surface formed a dense porous structure and increased roughness. The protein content, dielectric properties, and amino acid content of sample also changed significantly with the changes in the treatment conditions. Non-thermal PEF has potential applications in the development of hypoallergenic foods.

Universal Design and Efficient Synthesis for High Ambipolar Mobility Emissive Conjugated Polymers.

High ambipolar mobility emissive conjugated polymers (HAME-CPs) are perfect candidates for organic optoelectronic devices, such as polymer light emitting transistors. However, due to intrinsic trade-off relationship between high ambipolar mobility and strong solid-state luminescence, the development of HAME-CPs suffers from high structural and synthetic complexity. Herein, a universal design principle and simple synthetic approach for HAME-CPs are developed. A series of simple non-fused polymers composed of charge transfer units, π bridges and emissive units are synthesized via a two-step microwave assisted C-H arylation and direct arylation polymerization protocol with high total yields up to 61 %. The synthetic protocol is verified valid among 7 monomers and 8 polymers. Most importantly, all 8 conjugated polymers have strong solid-state emission with high photoluminescence quantum yields up to 24 %. Furthermore, 4 polymers exhibit high ambipolar field effect mobility up to 10-2 cm2 V-1 s-1, and can be used in multifunctional optoelectronic devices. This work opens a new avenue for developing HAME-CPs by efficient synthesis and rational design.

Universal Design and Efficient Synthesis for High Ambipolar Mobility Emissive Conjugated Polymers

AbstractHigh ambipolar mobility emissive conjugated polymers (HAME‐CPs) are perfect candidates for organic optoelectronic devices, such as polymer light emitting transistors. However, due to intrinsic trade‐off relationship between high ambipolar mobility and strong solid‐state luminescence, the development of HAME‐CPs suffers from high structural and synthetic complexity. Herein, a universal design principle and simple synthetic approach for HAME‐CPs are developed. A series of simple non‐fused polymers composed of charge transfer units, π bridges and emissive units are synthesized via a two‐step microwave assisted C−H arylation and direct arylation polymerization protocol with high total yields up to 61 %. The synthetic protocol is verified valid among 7 monomers and 8 polymers. Most importantly, all 8 conjugated polymers have strong solid‐state emission with high photoluminescence quantum yields up to 24 %. Furthermore, 4 polymers exhibit high ambipolar field effect mobility up to 10−2 cm2 V−1 s−1, and can be used in multifunctional optoelectronic devices. This work opens a new avenue for developing HAME‐CPs by efficient synthesis and rational design.

Effects of high voltage electrostatic field assisted freezing enhanced with ultrahigh permittivity ceramic on quality attributes of grass carp (Ctenopharyngodon idella) fillets during frozen storage

Small sample capacity is a critical limitation for the industrialization of the high voltage electrostatic field assisted freezing (HVEFF) technique. In this study, using grass carp as a sample, the effects of ultrahigh permittivity ceramic enhanced HVEFF system on the quality attributes of grass carp (Ctenopharyngodon idella) fillets during freezing and frozen storage were investigated. The appropriate electrostatic field strength for freezing grass carp fillets was determined first with the HVEFF Peltier cooling platform and then used for the freezing and frozen storage of grass carp fillets in an HVEFF refrigerator at −18 °C. The biochemical qualities, and ice crystal morphology of the samples were measured every 2, 4, 6, and 8 weeks during frozen storage. Compared to the frozen control, this novel HVEFF system could effectively delay the deterioration of texture and water migration, and reduce TVB-N, TBARS and the equivalent ice crystal diameters. This study not only showed the positive effect of this novel HVEEF system on the frozen preservation of grass carp fillets but more importantly provided a solution to the bottleneck of HVEFF industrialization.

Analytical Model of Optical-Field-Driven Subcycle Electron Tunneling Pulses from Two-Dimensional Materials.

We develop analytical models of optical-field-driven electron tunneling from the edge and surface of free-standing two-dimensional (2D) materials. We discover a universal scaling between the tunneling current density (J) and the electric field near the barrier (F): In(J/|F|β) ∝ 1/|F| with β values of 3/2 and 1 for edge emission and vertical surface emission, respectively. At ultrahigh values of F, the current density exhibits an unexpected high-field saturation effect due to the reduced dimensionality of the 2D material, which is absent in the traditional bulk material. Our calculation reveals the dc bias as an efficient method for modulating the optical-field tunneling subcycle emission characteristics. Importantly, our model is in excellent agreement with a recent experiment on graphene. Our results offer a useful framework for understanding optical-field tunneling emission from 2D materials, which are helpful for the development of optoelectronics and emerging petahertz vacuum nanoelectronics.

Quantum octets in high mobility pentagonal two-dimensional PdSe2

Two-dimensional (2D) materials have drawn immense interests in scientific and technological communities, owing to their extraordinary properties and their tunability by gating, proximity, strain and external fields. For electronic applications, an ideal 2D material would have high mobility, air stability, sizable band gap, and be compatible with large scale synthesis. Here we demonstrate air stable field effect transistors using atomically thin few-layer PdSe2 sheets that are sandwiched between hexagonal BN (hBN), with large saturation current > 350 μA/μm, and high field effect mobilities of ~ 700 and 10,000 cm2/Vs at 300 K and 2 K, respectively. At low temperatures, magnetotransport studies reveal unique octets in quantum oscillations that persist at all densities, arising from 2-fold spin and 4-fold valley degeneracies, which can be broken by in-plane and out-of-plane magnetic fields toward quantum Hall spin and orbital ferromagnetism.