Search

The non-degradable nature of petroleum-based plastics and the dependence on petroleum-based products in daily life and production are dilemmas of human development today. We hereby developed a plastic waste upcycling process to address these challenges. A multi-stream fraction strategy was developed to process poly (ethylene terephthalate) (PET) plastics into soluble and insoluble fractions. The soluble fraction was used as a sole carbon source for microbial fermentation to produce biodiesel precursor lipids with an appreciable bioconversion yield. The insoluble fraction containing fractionated polymers was used as the asphalt binder modifiers. The downsized PET additive improved the high-temperature performance of the asphalt binder by 1 performance grade (PG) without decreasing the low-temperature PG. Subsequent SEM imaging unveiled alterations in the micromorphology induced by PET incorporation. Further FTIR and 1H NMR analysis highlighted the aromatic groups of PET polymers as a crucial factor influencing performance enhancement. The results demonstrated the multi-stream fraction as a promising approach for repurposing plastic waste to produce biodiesel and modify asphalt. This approach holds the potential to tackle challenges in fuel supply and enhance infrastructure resilience to global warming. [ABSTRACT FROM AUTHOR]

High accuracy and a high spatiotemporal resolution of precipitation are essential for the hydrological, ecological, and environmental fields. However, the existing daily gridded precipitation datasets, such as remote sensing products, are limited both by the coarse resolution and the low accuracy. Despite considerable efforts having been invested in downscaling or merging, a method of coupled and simultaneously downscaling and merging multiple datasets is currently lacking, which limits the wide application of individual popular satellite precipitation products. For the first time, in this study, we propose a simple coupled merging and downscaling (CMD) method for simultaneously obtaining multiple high-resolution and high-accuracy daily precipitation datasets. A pixel-repeated decomposition method was first proposed, and the random forest (RF) method was then applied to merge multiple daily precipitation datasets. The individual downscaled dataset was obtained by multiplying the result of merging by an explanatory rate obtained by RF. The results showed that the CMD method exhibited significantly better performance compared with the original datasets, with the mean absolute error (MAE) improving by up to 50%, the majority of the values of bias ranging between −1 mm and 1 mm, and the majority of the Kling–Gupta efficiency (KGE) values being greater than 0.7. CMD was more accurate than the widely used dataset, Multi-Source Weighted-Ensemble Precipitation (MSWEP), with a 43% reduction in the MAE and a 245% improvement in the KGE. In addition, the long-term estimation suggested that the proposed method exhibits stable good performance over time. [ABSTRACT FROM AUTHOR]

Variations in precipitation have a great influence on human society and the natural environment. Existing studies have provided substantial information regarding variations in the magnitude, frequency, and intensity of precipitation. However, little is known about how the start and end dates of precipitation change, which could offer crucial insights for related studies in agriculture, hydrology, and other related disciplines. Here, we present an analysis of variations in the start date, end date, and frequency of different precipitation intensities, using a widely used gauge-satellite-reanalysis-based merging product, during the latest period, 1980–2022, across China. The results show that the spatial–temporal variations in the start date, end date, and frequency of different precipitation intensities were complex among regions. For example, in northeast and northwest China, light precipitation (LP) started earlier and increased in frequency during the study period. In the Tibetan Plateau, precipitation at different intensities levels started earlier, heavy precipitation (HP) and violent precipitation ended earlier, and the frequency of LP and moderate precipitation increased significantly. The start date of HP shifted earlier in Southeast China (−0.28 days/year). Our findings could be helpful in providing a comprehensive understanding of precipitation changes under global warming and highlight the need to pay close attention to these precipitation changes in the future. [ABSTRACT FROM AUTHOR]

There is an urgent need for a comprehensive assessment of cropland fragmentation that can provide valuable insights for guiding policies related to cropland protection, restoration, and other relevant measures. Despite the growing number of studies focusing on cropland fragmentation, a nationwide, long-term, and fine-scale understanding of the spatiotemporal changes in cropland fragmentation across China remains lacking. This study aimed to construct a novel comprehensive index that quantitatively assesses the level of farmland fragmentation, to fully elucidate the spatial and temporal dynamics of farmland fragmentation in China at the county level over the last two decades, and to identify the relationships between farmland fragmentation and key factors from anthropogenic and natural perspectives. Utilizing the 30 m annual and continuous time series Landsat-derived annual China land cover dataset (CLCD) from 2000 to 2021, we integrated three landscape pattern metrics- patch density (PD), mean patch area (MPA), and edge density (ED)- to devise a new comprehensive cropland fragmentation index (CFI). We also developed a Beta regression method to identify the relationships between CFI and key factors from human and natural perspectives. The results show that counties with high cropland fragmentation (CFI > 0.8) are predominantly located in the central part of China and the coastal areas, and the counties with low cropland fragmentation (CFI < 0.2) are mainly in the North China Plain, the Northeast Plain, and some areas in the northwest. Among counties experiencing an increase or decrease in fragmentation, the primary types of cropland conversions are between cropland and grassland, as well as between cropland and forests. A third major type of conversion involves the transformation of cropland into impervious surfaces. CFI had a significantly negative linear relationship with total area of cropland in each county while showing a positive relationship with the total cropland patches in each county. The variables CFI and slope, and CFI and nighttime light (NTL) data, exhibited a quadratic parabolic relationship. The findings presented in this study provide crucial insights into the underlying causes and patterns of farmland fragmentation in China. These insights will serve as a valuable resource for policymakers and land managers, enabling them to devise effective strategies for sustainable land use planning and promoting rural development in the country. [Display omitted] • Limited knowledge on fine-scale cropland fragmentation in China • A new synthetic cropland fragmentation index (CFI) was developed. • Counties with high and low CFI were identified during the lastest two decades. • Primary cropland conversions: cropland to grassland and forests, and cropland to impervious surfaces. • The relationships between CFI and influencing factors and their thresholds were detected. [ABSTRACT FROM AUTHOR]

The wireless power supply solution has shown great advantages in rail transit applications, such as maglev trains and trams. However, research works on designing the magnetic coupler for wireless charging system in rail applications, which is a crucial problem, are not sufficient. Considering the high power and lightweight requirements, this article selects the coaxial M-shape magnetic coupler with LCL/S compensation for railway applications, which contains the transmitting rail and the receiving coil wound on an M-shape magnetic core. First, analysis was conducted on the requirements for inductance parameters of the magnetic coupler under the circuit constraints, including transmission power, input and output voltages, and component electrical stress, etc. Then, the influence of the geometric parameters of the coil structure and misalignment on its inductance parameters is analyzed. Based on these analysis results, the design method for the M-type magnetic coupler based on the lightweight principal is proposed. The geometric parameters are designed following a certain sequence to minimize the number of iterations and FEM simulation parameter sweeps, making the design procedure suitable for engineering practice. According to the proposed method, the magnetic coupler for a 360 kW wireless charging tram is designed and implemented. Through simulations and experiments, the magnetic coupler is verified to be feasible for the system with light weight. [ABSTRACT FROM AUTHOR]

Autism spectrum disorder (ASD) is a brain-based neurodevelopmental disorder characterized by behavioral abnormalities. Accumulating studies show that the gut microbiota plays a vital role in the pathogenesis of ASD, and gut microbiota transplantation (GMT) is a promising technique for the treatment of ASD. In clinical applications of GMT, it is challenging to obtain effective transplants because of the high costs of donor selection and heterogeneity of donors' gut microbiota, which can cause different clinical responses. In vitro batch culture is a fast, easy-to-operate, and repeatable method to culture gut microbiota. Thus, the present study investigates the feasibility of treating ASD with in vitro cultured gut microbiota as transplants. We cultured gut microbiota via the in vitro batch culture method and performed GMT in the maternal immune activation (MIA)–induced ASD mouse model with original donor microbiota and in vitro cultured microbiota. Open field, three-chamber social, marble burying, and self-grooming tests were used for behavioral improvement assessment. Serum levels of chemokines were detected. Microbial total DNA was extracted from mouse fecal samples, and 16S rDNA was sequenced using Illumina. Our results showed that GMT treatment with original and cultured donor gut microbiota significantly ameliorated anxiety-like and repetitive behaviors and improved serum levels of chemokines including GRO-α (CXCL1), MIP-1α (CCL3), MCP-3 (CCL7), RANTES (CCL5), and Eotaxin (CCL11) in ASD mice. Meanwhile, the gut microbial communities of the two groups that received GMT treatment were changed compared with the ASD mice groups. In the group treated with in vitro cultured donor gut microbiota, there was a significant decrease in the relative abundance of key differential taxa, including S24-7, Clostridiaceae, Prevotella_other, and Candidatus Arthromitus. The relative abundance of these taxa reached close to the level of healthy mice. Prevotella_other also decreased in the group treated with original donor gut microbiota, with a significant increase in Ruminococcaceae and Oscillospira. The present study demonstrated that GMT with in vitro cultured microbiota also improved behavioral abnormalities and chemokine disorders in an ASD mouse model compared with GMT with original donor gut microbiota. In addition, it significantly modified several key differential taxa in gut microbial composition. [ABSTRACT FROM AUTHOR]

For the bidirectional wireless power transfer (BWPT) technology, the phase synchronization between the transmitting and receiving converters is very essential and difficult to achieve by wireless communication between two sides because the delay and data transfer interval of wireless communication severely influence the control performance. This article proposes a novel control strategy for BWPT, which can achieve the phase synchronization and maximum efficiency point tracking independent of the real-time wireless communication. To solve the overshoot and oscillation problem incurred by the proposed control strategy and the nature of the system itself, the dynamics of a series–series compensated BWPT system is then analyzed and a small-signal model of this system is derived based on the generalized state space averaging and extended describing function methods. Using the small-signal model, a BWPT control system based on the proposed control strategy is designed and optimized. The validity of the proposed strategy and the performance of the control system are verified experimentally using a 3.3-kW prototype system. [ABSTRACT FROM AUTHOR]

• This study constructed a bivalent chimeric virus-like particle vaccine (ND-IBD cVLPs) displaying the ND virus (NDV) HN protein and the IBD virus (IBDV) VP2 protein. • ND-IBD cVLPs stimulated highly effective HI antibody levels against NDV HN protein and ELISA antibody levels against the IBDV VP2 protein. • ND-IBD cVLPs provided complete protection against virulent NDV and IBDV challenges and alleviated the pathological damage caused by viral infection. Newcastle disease (ND) and infectious bursal disease (IBD) pose significant threats to the chicken industry, causing substantial economic losses. Currently, immunization through vaccination is the most effective strategy to prevent ND and IBD but currently used traditional vaccines, including inactivated or attenuated vaccines, face challenges in achieving a balance between immunogenicity and safety. To develop a green and efficient novel vaccine for ND and IBD, we developed a bivalent chimeric virus-like particle vaccine (ND-IBD cVLPs) displaying the ND virus (NDV) HN protein and the IBD virus (IBDV) VP2 protein based on the ND VLPs carrier platform and insect baculovirus expression system. This study aimed to evaluate the immunogenicity and protective efficacy of ND-IBD cVLPs in specific pathogen-free chickens. Chickens were immunized with 50 µg of purified ND-IBD cVLPs at 7 days old, boosted at 21 days old, and challenged at 42 days old. The results demonstrated that ND-IBD cVLPs stimulated highly effective hemagglutination inhibition antibody levels against NDV HN protein and enzyme-linked immunosorbent assay antibody levels against the IBDV VP2 protein. Furthermore, ND-IBD cVLPs provided complete protection against virulent NDV and IBDV challenges and mitigated pathological damage to the lung caused by NDV infection and the bursa of Fabricius caused by IBDV infection. These findings suggest that ND-IBD cVLPs hold promise as a safe and efficient novel vaccine candidate for the effective prevention of ND and IBD, extending the development of a foreign protein delivery platform of ND VLPs. [ABSTRACT FROM AUTHOR]

In many practical applications of wireless power transfer, the battery, which can be modeled as a voltage source, is charged wirelessly from the voltage-source inverter via the transmitter and the receiver. Therefore, it is crucial to analyze such a wireless power transfer system. In this paper, the closed-form oriented modeling and analysis of the wireless power transfer system with the constant-voltage source and load are conducted. Two cases are studied: both the transmitter and the receiver are under resonance, and only the receiver is under resonance. In the latter case, the transmitter is set to be inductive for the implementation of zero voltage switching. The battery current, the output power, and the transfer efficiency of both cases are analyzed and compared in detail. The voltage gain, the power factor, and the output power of the latter case are studied to offer physical insights and design guidelines. An experimental prototype is implemented to verify the analysis. The experiments agree with the calculations. [ABSTRACT FROM AUTHOR]

The nonlinear junction capacitances of power devices are critical for the switching transient, which should be fully considered in the modeling and transient analysis, especially for high-frequency applications. The silicon carbide (SiC) MOSFET combined with SiC Schottky Barrier Diode (SBD) is recognized as the proposed choice for high-power and high-frequency converters. However, in the existing SiC MOSFET models only the nonlinearity of gate-drain capacitance is considered meticulously, but the drain–source capacitance, which affects the switching commutation process significantly, is generally regarded as constant. In addition, the nonlinearity of diode junction capacitance is neglected in some simplified analysis. Experiments show that without full consideration of nonlinear junction capacitances, some significant deviations between simulated and measured results will emerge in the switching waveforms. In this paper, the nonlinear characteristics of drain–source capacitance in SiC MOSFET are studied in detail, and the simplified modeling methods for engineering applications are presented. On this basis, the SiC MOSFET model is improved and the simulation results with improved model correspond with the measured results much better than before, which verify the analysis and modeling. [ABSTRACT FROM AUTHOR]

The noninverting buck–boost (NIBB) converter is a step-up and step-down dc–dc converter suitable for applications with a wide input voltage range. However, this circuit will face the problem of operating mode switching when the input voltage is close to the output voltage. Considering this problem, the principles of the NIBB converter are analyzed in this article. The duty cycle combinations of an NIBB converter are analyzed, and an analysis method for the mode transition problem from a geometric perspective is proposed. Using the two-edge pulsewidth modulation method, a novel bumpless mode transition control method is proposed. A nonlinear feedforward controller with hysteresis is designed according to the state equation of the circuit. Moreover, the inductor current reference value is compensated when the mode is switched so that the mode transition problem of the NIBB circuit is effectively solved. In addition, a small-signal analysis of the proposed method is performed. The analysis shows that the proposed method has good stability and dynamic performance in various typical conditions. A 10-kW NIBB prototype is built in this article, and the corresponding experimental scenarios are designed. The experimental results show that compared with the results of unified PI control during the mode transition, the transient oscillation of the output voltage is smaller, and the duration of the transient process is shorter. [ABSTRACT FROM AUTHOR]

A solute-saturated supercritical fluid loading (SSFL) process was proposed to load 2-phenylethyl alcohol (PEA) in silica and activated carbon (AC). The adsorption and loading amounts of PEA in carries were investigated at different temperatures (50.0–60.0 °C) and pressures (8.0–14.0 MPa) by a column sampling method. By using a high-pressure quartz spring method, the adsorption amounts of the binary PEA and CO 2 in silica were determined. The retention of PEA in the SSFL powder flavors was evaluated by a nitrogen-purging method. Results revealed that, compared with AC, silica had high loading of PEA (maximum 0.484 g/g) and showed better results in PEA preservation from loss at room temperature and control release at higher temperature; PEA suppressed the adsorption of CO 2 at relatively high pressure. Discussion indicated that precipitation and adsorption contributed to the high loading of PEA in silica, while adsorption mainly contributed to that in AC. [ABSTRACT FROM AUTHOR]

Feedstock design is crucial for lignocellulosic biomass use. Current strategies for feedstock design cannot be readily applied to improve the quality of biomass-based materials, limiting the sustainability and economics of lignocellulosic biorefineries. Recent studies have advanced the understanding of biomass structure–property relationships and discovered several characteristics, such as molecular weight, uniformity, linkage profile, and functional groups, that are critical for manufacturing diverse quality biomaterials. These discoveries call for fundamentally different strategies for feedstock development. Such strategies need to rediscover the roles of monolignol biosynthesis enzymes and leverage lignin polymerization enzymes to achieve precise control of lignin molecular structure. These innovations could transform biomass into feedstock for high-quality biomaterials, addressing essential environmental challenges and empowering the bioeconomy. Biomaterial manufacturing is critical in empowering the bioeconomy as well as sustainability and cost-effectiveness of lignocellulosic biorefineries. Lignin and cellulose could be renewable, abundant, and low-cost biopolymers for synthesizing a diverse range of functional materials to promote energy and environmental sustainability. Conventional understanding of key biomass characteristics for carbohydrate saccharification does not inform biomaterial synthesis and quality, and a new understanding of the structure–property relationship is needed, particularly for lignin. Recent advances have identified lignin molecular weight, uniformity, linkage profile, and functional group as the new key biomass characteristics for biomaterial manufacturing. Feedstock design can derive the aforementioned biomass features, empowering high-quality material synthesis. Transforming biomass into feedstock for various high-quality materials can address a broad range of environmental challenges and empower the bioeconomy. [ABSTRACT FROM AUTHOR]

The multiactive-bridge (MAB) structure has obvious efficiency and cost advantages in multiport power electric transformer, but it brings the characteristics of strong current coupling of each transformer. To improve the dynamic response speed of MAB and reduce the coupling characteristics, a high-frequency current predictive control (CPC) method for MAB is proposed in this letter. The controller uses the enhanced single-phase shift modulation method to adjust the phase shift angle and duty cycle of four ports at the same time so that the high-frequency current can be adjusted in several switching cycles. In the proposed CPC method, the influence of control delay is analyzed and compensated, and the dc offset, which may occur in the dynamic process is analyzed and gives corresponding solutions. More importantly, the proposed CPC method can be extended to the power predictive control method to realize power decoupling of multiple ports of MAB. The parameter robustness of current and power predictive control is analyzed briefly in this letter. The proposed control method is validated on a hardware-in-loop simulation platform based on RT-lab. Experiment results show the superior dynamic performance and good robustness of the proposed method. [ABSTRACT FROM AUTHOR]

Based on four-coil magnetically coupled resonant wireless power transfer, this paper demonstrates, explains, and analyzes the frequency-splitting phenomenon by using the circuit theory. First, the complete and simplified models are built to describe the whole system. The numerical formulas of the system efficiency both at and away from the resonant frequency are presented. Then the frequency-splitting phenomenon is displayed and further explained mathematically and physically. An important factor for frequency splitting is introduced. The boundary condition for frequency splitting and its splitting frequency points are deduced. The amplitude–frequency and phase–frequency characteristics of the input impedance are measured and described to verify the explanation. Three related factors are studied, and the sensitivity analysis is conducted. A solution is proposed that helps improve the efficiency when frequency splitting occurs. The theoretical calculations and experimental results provide a sound basis. [ABSTRACT FROM AUTHOR]

Recent years have witnessed the booming development of resonant wireless power transfer (RWPT). Compared with conventional inductive power transfer, the frequency of RWPT is usually much higher. To reduce the resonant frequency while maintaining the transfer efficiency constant at the same transfer distances, two solutions are proposed and realized in this letter. Two fundamental structures for RWPT are analyzed and the expressions of the transfer efficiency are deduced. It is pointed out that the transfer quality factor and the load matching factor are two important factors of achieving high transfer efficiency. The larger the transfer quality factor, the higher the transfer efficiency. There is an optimal load matching factor to reach the highest transfer efficiency. The transfer efficiency can remain constant at the same distances if the transfer quality factor is kept at the same level and the load is matched. Theoretical calculations and experimental results provide a sound basis for decreasing frequency. [ABSTRACT FROM AUTHOR]

Multileg Class-D amplifiers (CDAs) with phase-shifted carrier modulation can increase the equivalent switching frequency and reduce the output current ripples, which further reduces the size of the output filter. However, these benefits are degraded by the tolerances in the phase inductance values. The phase inductance mismatches impact the ripple cancelation effects (the harmonic contents at switching frequency and its harmonics appearing in the output current ripple). Therefore, the quality of the output waveform can further be impacted. Current research works dealing with this issue mainly focused on the interleaved dc–dc converters, which does not cover the analysis in multileg CDAs or inverters, especially for the full-bridge configuration. This paper proposes a general analytical method to characterize the steady-state phase and the total current ripple in the multileg CDAs with full-bridge configuration under inductance mismatches. Monte Carlo simulation is used to study the impact of inductance mismatches on the harmonic contents of the total current ripple, and the distribution law of the inductances at the worst case is revealed. The analytical method is verified by simulation and experimental results of a four-leg full-bridge CDA. A design guideline is given to optimize the filter design based on the analytical method. [ABSTRACT FROM AUTHOR]

Highlights • Optimal DWPT rollout reduces life cycle GHG & energy by up to 9% & 7% respectively. • Roadside solar panels are essential to reduce DWPT life cycle energy and GHG. • Electrifying up to 3% of roadways downsizes EV battery capacity by up to 48% • GHG and energy burdens can break even within 20 years, but costs beyond 20 years. • The cost of GHG mitigation by DWPT is $556/tonne of mitigated GHG. Abstract Dynamic wireless power transfer (DWPT), or dynamic wireless charging technology, enables charging-while-driving and offers opportunities for eliminating range anxiety, stimulating market penetration of electric vehicles (EVs), and enhancing the sustainability performance of electrified transportation. However, the deployment of wireless charging lanes on highways and urban road networks can be costly and resource-intensive. A life cycle assessment (LCA) is conducted to compare the sustainability performance of DWPT applied in a network of highways and urban roads for charging electric passenger cars. The assessment compares DWPT to stationary wireless charging and to conventional plug-in charging using a case study of Washtenaw County in Michigan, USA over 20 years. The LCA is based on three key sustainability metrics: costs, greenhouse gas (GHG) emissions, and energy burdens, encompassing not only the use-phase burdens from electricity and fuel, but also the upfront deployment burdens of DWPT infrastructure. A genetic algorithm is applied to optimize the rollout of DWPT infrastructure both spatially and temporally in order to minimize life cycle costs, GHG, and energy burdens: (1) spatial optimization selects road segments to deploy DWPT considering traffic volume, speed, and pavement remaining service life (RSL); (2) temporal optimization determines in which year to deploy DWPT on a particular road segment considering EV market share growth as a function of DWPT coverage rate, future DWPT cost reduction, and charging efficiency improvement. Results indicate that optimal deployment of DWPT electrifying up to about 3% of total roadway lane-miles reduces life cycle GHG emissions and energy by up to 9.0% and 6.8%, respectively, and enables downsizing of the EV battery capacity by up to 48%, compared to the non-DWPT scenarios. Roadside solar panels and storage batteries are essential to significantly reduce life cycle energy and GHG burdens but bring additional costs. Breakeven analysis indicates a breakeven year for solar charging benefits to pay back the DWPT infrastructure burdens can be less than 20 years for GHG and energy burdens but longer than 20 years for costs. A monetization of carbon emissions of at least $250 per metric tonne of CO 2 is required to shift the optimal "pro-cost" deployment to the optimal "pro-GHG" deployment. A roadway segment with volume greater than about 26,000 vehicle counts per day, speed slower than 55 miles per hour (1 mile ≈ 1.609 km), and pavement RSL shorter than 3 years should be given a high priority for early-stage DWPT deployment. [ABSTRACT FROM AUTHOR]

• m6A modification may play an important role in controlling NDV replication by regulating gene expression. • mRNAs with differential expression levels and m6A modification abundance are mainly enriched in antiviral signaling pathways. • This is the first comprehensive characterization of m6A profiles in the transcriptome of chicken macrophages post NDV infection. N6-methyladenosine (m6A) modification, the most prevalent post-transcriptional modification of eukaryotic mRNAs, is reported to play a crucial role in viral infection. However, the role of m6A modification during Newcastle disease virus (NDV) infection has remained unclear. In this study, we performed MeRIP-seq to investigate the transcriptome-wide m6A methylome and m6A-modified genes in NDV-infected chicken macrophages. A total of 9496 altered peaks were identified, of which 7015 peaks were significantly upregulated across 3320 genes, and 2481 peaks were significantly down-regulated across 1264 genes. Combined analysis of m6A peaks and mRNA expression showed that 1234 mRNAs had significantly altered levels of methylation and expression after NDV infection, and m6A modification tended to have a negative relationship with mRNA expression, suggesting that m6A modification may regulate the process of NDV infection by regulating gene expression, particularly of the genes important in the innate immune response. To the best of our knowledge, this is the first comprehensive characterization of m6A patterns in chicken macrophage mRNA after NDV infection, providing a valuable basis for further exploring the role of m6A modification mechanisms during the course of NDV infection. [ABSTRACT FROM AUTHOR]

The load coils are employed for multiple loads of resonant wireless power transfer in this paper. With the addition of the load coil, this three-coil structure has easy access to transferring power to multiple loads with the advantages of a compact structure and controllable power flow. Both single-load transfer and multiple-load transfer are modeled and analyzed by means of the circuit theory. The transfer quality factor and the load matching factor are utilized in the analysis of efficiency. In the single-load transfer, the load matching condition is fully explored. Based on the single-load transfer, the multiple-load transfer is researched. The double-load transfer, acting as an illustration, is studied with the uncoupled and coupled load coils. Equivalent reflected resistances are introduced to decouple the model of the double-load transfer with coupled load coils mathematically. An experimental prototype is implemented to verify the aforementioned analysis. The experimental results agree with the theoretical calculations. [ABSTRACT FROM AUTHOR]

In multiple receivers of resonant wireless power transfer, selective power flow among the loads is an important issue. This paper proposes a new method to control power division. The two-coil structure with different resonant frequencies of the sending and receiving loops is modeled and analyzed. The efficiency is proved to peak at the resonant frequency of the receiving loop, regardless of the resonant frequency of the sending loop. Using this feature, selective power transfer can be achieved by setting the receiving loops at different resonant frequencies. The efficiency of a particular load is greatly influenced by the driving frequency. The multiple-load system with different resonant frequencies is modeled and the efficiency expression of each load is deduced. The mutual inductances of the receiving coils have a small impact on the efficiency distribution. The closer the resonant frequencies of the receiving loops, the less isolated the related loads. The calculations and the experiments confirm the analysis. [ABSTRACT FROM AUTHOR]