Carrier Power Research Articles

Design of Broadband Doherty Power Amplifier Based on Spoof Surface Plasmon Polaritons

ABSTRACTSpoof surface plasmon polariton (SSPP) is a technique for controlling and manipulating electromagnetic waves within the microwave frequency range through ultrathin corrugated metallic strips. According to current research, SSPPs are primarily used for designing passive circuits and single‐ended power amplifiers (PAs). This work employs SSPP theory for the design of a broadband high‐efficiency Doherty power amplifier (DPA). The input and output matching networks of the carrier power amplifier (CPA) and peak power amplifier (PPA) are designed based on SSPP structure in order to improve the back‐off (BO) efficiency of the DPAs. Results of measurements indicate that the proposed height‐variable SSPP‐based DPA achieves a saturated output power of 41.4 dBm and a maximum efficiency of 61.1% within the frequency range of 1.6–2.2 GHz, whereas BO efficiency remains above 51.2%, demonstrating the effectiveness of the proposed techniques.

PM6/L8‐BO Thin Films through Layer‐by‐Layer Engineering: Formation Mechanism, Energetic Disorder, and Carrier Mobility

ABSTRACTLayer‐by‐layer (LBL) process has emerged as a promising method in the advancement of organic photovoltaics, emphasizing scalability and reproducibility. More importantly, it provides enhanced morphological control for boosting carrier mobility (μ) and power conversion efficiency. By employing a multiscale approach that combined first‐principles calculations, molecular dynamics simulations, and kinetic Monte Carlo methods, the relationship between LBL morphology engineering and carrier mobility in donor/acceptor (PM6/L8‐BO) thin films is elucidated. During solvent evaporation, the order of solid‐phase formation in LBL films was top surface, bottom region, and then the middle region. The early solid precipitation from precursor solutions was acceptor, resulting in a well‐ordered molecular arrangement and reducing energy disorder of acceptor LUMO levels. Furthermore, the difference in energy disorders between the A/D blend region and the pure A or D domains enabled LBL morphology engineering to balance electron and hole mobilities, thereby mitigating charge accumulation and recombination. LBL‐manufactured films presented higher carrier mobility ( = = 1.9 × 10−3 cm2 V−1 s−1) compared to bulk heterojunction (BHJ) films ( > = 0.1 × 10−3 cm2·V−1 s−1). These mechanisms provided insights into strategies for enhancing charge extraction of photo‐generated charge carriers through LBL engineering, driving the development of efficient organic photovoltaic materials.

Comprehensive Analysis of Design Trends in Scattered Power Systems Utilizing Hydrogen as the Power Carrier

In this paper, the technological applications of hydrogen in the distributed energy systems are explored and various technological solutions such as gasification units, fuel cells, electrolyzers, hydrogen storage methods and methanation reforming reactors are analyzed. The study shows that electrolysis and fuel cells are widely recognized as the preferred technologies for incorporating hydrogen into energy systems, with alkaline electrolyzers in particular being favored for their greater capacity and technological advantages. Besides, research on hydrogen storage has focused on gas storage methods, as liquefied hydrogen requires great economic and energy inputs at low temperatures and high pressures. End uses of hydrogen include hybrid fuels, storage media and industrial raw materials. The results show that the widespread use of hydrogen energy storage is a direct result of the integration of renewable resources and indicate the potential of distributed energy systems for the sustainable provision of transportation fuels and raw materials. In addition, it analyzes a systematic assessment of hydrogen as an energy source, focusing on economic, technological, and environmental issues, noting that about 80% of the studies focus on economic factors, and emphasizes the importance of establishing an integrated framework to facilitate the application of hydrogen technology

Influence of Sb content on carrier transport and thermoelectric properties of flexible Bi–Sb films

In this study, the Bi–Sb films with different Sb content on silicon and polyimide (PI) substrates were successfully fabricated via high vacuum magnetron sputtering and the carrier transport and thermoelectric properties were studied. As the Sb content increased, the carrier concentration, electrical conductivity, Seebeck coefficient, and power factor of deposited Bi–Sb films initially increased and then decreased at room temperature. The maximum Seebeck coefficient and power factor reached −108.90 μV K−1 and 0.133mW m−1 K−2 for the Bi84Sb16 film at room temperature. The electrical conductivity, Seebeck coefficient, and power factor of deposited Bi–Sb films increased with increasing energy gap. Whether bending toward or bending back toward, the relative electrical conductivity of the films decreased with increasing bending angle. When the bending angle was less than 90°, the electrical conductivity of the films decreased very little. However, the electrical conductivity of the films exhibited an obvious reduction when the bending angle exceeded 90°. The relative electrical conductivity of the deposited films under bending toward and bending back toward decreased by 4% and 8% under 180° bending angle, respectively. Compared with bending toward, the electrical conductivity of the films bending back toward (tensile) decreases even more at the same bending angle. The electrical conductivity of the films bending toward changed little and remained 94.1% after bending 1000 times at the radius of 3 mm. The maximum power density of a flexible thermoelectric generator for Bi84Sb16 film was 0.672 and 0.8644 W m−2 at ΔT = 30 and 39 K, respectively.

​Quantitative assessment of heavy metal concentrations, pollution levels, and sources apportionment in one of China's top 10 most livable cities.

Urban topsoil is not only an essential part of the urban ecosystem, but also a powerful carrier of pollutants in the urban environment. In this paper, 130 topsoil samples from urban area of Xinyang in central-eastern China were selected, the aim is to quantitatively investigate the concentrations, pollution levels, and sources apportionment of 8 heavy metals (HMs, encompassing arsenic (As), cobalt (Co), copper (Cu), chromium (Cr), lead (Pb), nickel (Ni), vanadium (V), and zinc (Zn)) via geochemical method. The main conclusions are as follows. (1) The eight HMs in the topsoil have been artificially enriched to varying degrees, which are lower than the street dust levels sampled in pairs. (2) Cu, Zn, and Pb were significantly contaminated, and As, Co, Ni, Cr, and V were relatively low levels of contamination. Overall, comprehensive pollution levels were particularly severe, with 30.0%, 39.2%, and 30.8% for slight, moderate, and serious pollution, respectively. (3) Co, Ni, V, and Cr predominantly originated from natural sources, the percentage contribution of which is 6.3%; Pb, As, Cu, and Zn were predominantly derived from traffic-derived sources, with a percentage contribution of 93.7%. Thus, the first-order source of HMs in the topsoil originates from traffic-induced activities, similar to the case of street dust. Our findings can be beneficial in providing local governments with a reference to formulate environmental pollution controls, and also provide a case study for environmental pollution control in the other livable cities in China.

Uniqueness of Albumin as a Carrier in Nanodrug Delivery

ABSTRACT In contemporary medicine, albumin nanoparticles have become a powerful and adaptable nanodrug carrier. The ability of human serum albumin to deliver hydrophobic drugs through passive and active targeting mechanisms demonstrates its versatility in treating a variety of disorders. In addition to discussing ongoing clinical trials using albumin-based formulations, this study emphasizes the benefits of albumin-bound Paclitaxel (Abraxane) over solvent-based formulations (Taxol). Future advancements in albumin-based therapeutics are made possible by the emphasis placed on the importance of albumin in improving drug performance and its potential as a drug delivery mechanism. Albumin nanoparticles show promise in the treatment of a variety of illnesses. This study emphasizes their use in the delivery of hydrophobic drugs, their benefits over formulations based on solvents, and their ongoing clinical trials. The medicinal potential of albuminNeutrophils, leveraging their inflammation-targeting capabilities, have emerged as innovative drug delivery carriers. Integrating neutrophils with nanotechnology enhances treatment efficacy and reduces side effects. This review explores neutrophil-based nano-drug delivery systems, including membrane-coated nanoparticles, cell-loaded nanoparticles, and chimeric antigen receptor (CAR)-neutrophils. These therapies demonstrate superior biocompatibility, targeting, and therapeutic robustness, showing promise in various disease treatments.Neutrophils, combined with nanotechnology, offer innovative drug delivery. This review covers design principles, mechanisms, and applications of neutrophil-based nano-drug delivery systems, highlighting enhanced biocompatibility, targeting, and therapeutic efficacy.

Microwave-assisted chemical looping gasification of sugarcane bagasse biomass using Fe3O4 as oxygen carrier for H2/CO-rich syngas production

Chemical looping gasification (CLG) is a promising approach for sustainable biomass utilization. The selection of an appropriate heating method is a key challenge in the CLG process. This study investigated microwave-assisted CLG of sugarcane bagasse using Fe3O4 as an oxygen carrier. The effects of microwave power (580, 680, 780, 880, and 980 W) and oxygen carrier to biomass mass ratio (mOC:mSCB) (0:6, 1:5, 2:4, 3:3, 4:2, and 5:1) on product distributions, syngas compositions, syngas efficiencies, and syngas HHVs were studied. Results showed that with increase in microwave power and mOC:mSCB ratio, syngas yield, syngas efficiency, and syngas HHV initially increased and then finally decreased. The optimal conditions were found to be 880 W power and a 3:3 ratio. The optimal syngas yield of 88.23 wt% was achieved in the air reactor at 880 W with a 5:1 ratio. Pyrolysis yielded H2 and CO-enriched syngas, while gasification increased CO concentration. The highest CO + H2 concentration of 64.96 vol% was obtained in the fuel reactor at 880 W with a 3:3 ratio. The maximum thermal efficiency (49.55 %), cold gas efficiency (49.48 %), carbon conversion efficiency (54.42 %), and HHV (16.31 MJ/Nm3) were observed in the fuel reactor at 880 W and a 3:3 ratio. Microwave-assisted heating achieved an impressive heating rate of 1166.40 °C/min at 980 W and 5:1 in air reactor. This study shows that microwave heating can be utilized as efficient heating in CLG for sustainable biomass utilization.

Alkylated RALA-Derived Peptides for Efficient Gene Delivery.

RALA is an amphipathic cationic peptide demonstrated to be a low-toxicity and high-efficiency delivery platform for the systemic delivery of nucleic acid therapeutics. This work reports three RALA-derived peptides modified with N-terminal palmitic acid, engineered through amino acid substitutions and truncated sequences. All three peptides have good nucleic acid encapsulation, release and uptake, biocompatibility, and endolysosome escape. The siRNA transfection efficiency is about 90%, and the silencing rate of GA (C16-GLFWHHHARLARALARHLARALRA) exceeds that of lipofectamine 2000 (siRNA concentration = 50 nM). Truncating the peptide chain while retaining a certain amount of arginine ensures an effective particle size. Replacing glutamic acid with three histidines ensures an effective zeta potential and accelerates the endosome escape process through the proton sponge phenomenon. Introducing phenylalanine enhances the carrier-cell interaction. We believe that they are powerful carriers of siRNA therapy and may have good application prospects in treating various diseases.

Steady-State Inverse-Temperature Crystallization Enabling Low Defect Perovskite Single Crystal and Efficient X-Ray Detectors.

Organic-inorganic halide perovskite single crystals (SCs) have shown great potential in radiation detection applications due to their large radiation stopping power and excellent carrier transport properties. The spatial-confined inverse-temperature crystallization (ITC) method has been widely adopted to obtain large-sized SCs. However, they usually face the problems of uneven stress distribution and high defect density due to the limited crystal growth space and varied growth rate with the increase in temperature, making it difficult to fabricate highly sensitive and stable radiation detectors. In this study, the steady-state inverse-temperature crystallization method (SS-ITC) is developed to regulate the growth process of SCs by controlling the growth speed precisely to achieve a constant rate of growth as the temperature increases. Compared with the conventional ITC-grown samples, the lattice spacing of SCs prepared by the SS-ITC method is reduced by 1.2% due to tensile stress relaxation, resulting in a lower defect density of 7.93×109cm-3 and a remarkable uniformity over a large area. As a result, the co-planar X-ray detectors based on these high-quality SCs exhibit a high sensitivity of 1.67×105 µC Gyair -1cm-2, representing the best performing MAPbBr3-based X-ray detectors reported to date.

Energetic and exergetic analysis of an AE-T100 micro gas turbine system fuelled by partially cracked ammonia

Abstract In recent years, ammonia has gained attention as a fuel for power generation purposes, especially due to its chemical characteristics which ensure reaching the target of zero-carbon emissions. Ammonia is also a powerful hydrogen carrier, with a solid and consolidated production method based on the Haber-Bosh process. By exploiting the ease of transport of ammonia that is liquid at moderately low pressures and temperatures, it can be converted to hydrogen and nitrogen through a cracking reaction directly at the power production plant site. Moreover, to reduce greenhouse gas emissions (GHG) in the production energy sector, small-scale power generation systems are today gaining more attention. In this context, the use of partially cracked ammonia mixtures in micro gas turbine fields represents an interesting solution in the distributed generation sector. In this work, an energetic and exergetic analysis of an AE-T100 mGT fuelled by partially cracked ammonia mixtures is carried out. The analysis has been performed by varying the ammonia cracking percentage according to the maximum achievable conversion by exploiting the thermal energy contained in mGT exhaust gases. The whole system has been modeled in MATLAB/Simulink environment and it includes not only the turbine but also the ammonia conditioning system required to bring the ammonia at the condition imposed by the mGT. Moreover, a comparison with the mGT fuelled by conventional fuel is carried out both from a thermodynamic and exergetic point of view.

Application Research of Power Measurement Data Exchange Based on Uninterruptible Power Supply

With the maturity of the smart meter embedded system integration mode, the power consumption information can be fed back to the management center by the intelligent terminal through the power Internet of Things. The smart terminal adopts the narrowband data communication mode. However, the narrowband channel interval is hindered by interference signals, resulting in serious data packet loss. Therefore, a stable and efficient acquisition scheme is needed to ensure its smooth interaction. Based on the application of smart meter data communication, we analyze the power consumption optimization and carrier transmission optimization of the power Internet of Things and propose a data analysis method based on self-learning and external characteristics, which is used to calculate the offline execution strategy of smart meters when they encounter factors such as power outage or intrusion. A production task-driving rule is designed. The external characteristics of deep learning data of the power Internet of Things are collected. The accuracy of data classification is judged according to the parallel Internet of Things of a convolutional neural network and a long-term and short-term memory deep neural network. When dealing with high-dimensional original data, the data network is graded to reduce the work of feature selection and the difficulty of training. Moreover, we improve the autonomous execution ability of an embedded terminal device in an offline state. We also strengthen the ability of abnormal data detection and judgment learning to meet the requirements of efficient and stable operation of the power grid. Simulation results verify that compared with the current mainstream schemes, the performance of the proposed scheme is improved by more than 17%. Besides, the fault tolerance rate is enhanced by 29%, and the power consumption after optimization is reduced by 26.3% and 42.8%. These effects highlight the role of data processing in embedded systems. It solves the problem of abnormal data and energy loss affecting the accuracy of error estimation of electric energy meters, opens up a new way for data acquisition and processing of large-scale smart meters, and further improves the service level of information management of power systems.

Water/oil interfacial photocatalysis of amphiphilic CdS/Bi2WO6 S-scheme heterojunctions for efficient production and spontaneous separation of H2O2 and value-added organics

The photocatalytic co-production of H2O2 and value-added organics in a suitable water/oil biphasic system offers an intriguing strategy to address the challenges encountered in a single liquid-phase solution, including the efficient separation of H2O2 and organic products as well as the mitigation of undesirable secondary reactions. For this, exploring amphiphilic photocatalysts with high performance is highly required. Herein, an amphiphilic CdS/Bi2WO6 S-scheme heterojunction photocatalyst is designedly synthesized through a two-step solvothermal process, aiming to achieve efficient interfacial photocatalytic reactions at the water/oil interface for simultaneous generation and selective separation of H2O2 and organic products. The CdS/Bi2WO6 heterojunction photocatalyst exhibits enhanced light absorption in UV–visible region, increased electron-hole separation efficiency, and powerful charge carriers with high redox abilities. Moreover, the formation of S-scheme heterojunction improves the catalyst stability by preventing CdS from photocorrosion. As a result, the production rate of H2O2 reaches up to 216.76 mmol g−1 h−1, accompanied by the generation of organic products (benzaldehyde: 104.91 mmol g−1 h−1, benzoic acid: 49.88 mmol g−1 h−1, and benzyl benzoate: 38.01 mmol g−1 h−1), in a water/benzyl-alcohol biphasic system under simulated sunlight irradiation. The photocatalytic mechanism is elucidated based on the results of comprehensive experiments and characterizations. This study highlights a rational construction of amphiphilic photocatalysts and their application in organic/water interfacial photocatalytic reactions.

Rational composition engineering toward high thermoelectric performance in p-type EuMg2Sb2-based materials

Mg-based compounds are emerging materials for efficient thermoelectric conversion, as exemplified by n-type Mg3Sb2-based materials, while a high performing p-type Mg3Sb2 material is lacking. EuMg2Sb2, a derivative of Mg3Sb2, has revealed potential as a high-performance alternative to p-type Mg3Sb2-based materials, while pristine EuMg2Sb2 suffers from low carrier concentration. Herein, we reveal that both Zn substitution for Mg and Yb substitution for Eu not only boost the carrier concentration and mobility of p-type EuMg2Sb2-based materials, but also sharply diminish the lattice thermal conductivity via enhancing phonon scattering. Band structure calculation shows that Zn substitution minimizes the energy difference between different bands at the valence band maximum and reduces the band effective mass, leading to optimized band structure. Combined with the role of Ag doping in increasing the carrier concentration and power factor, p-type Eu0.5Yb0.5Mg1.0975Zn0.9975Ag0.005Sb2 sample obtains a maximal dimensionless figure of merit (zT) value of 1.18 at 823 K, which compares favorably to those of EuMg2Sb2 and other p-type Mg–Sb-based Zintl materials. This study demonstrates the efficacy and importance of delicate composition engineering in boosting the thermoelectric performance of p-type EuMg2Sb2.

Unfolding the mysterious roles of GeTe/SnTe compositing within CuInTe2 thermoelectric alloy: Short-range and local chemical orders

The optimization of thermoelectric (TE) properties in TE materials requires controlling intrinsic factors such as order/disorder in crystal and chemical structures. Although heterogeneous interfaces play a key role in regulating TE properties, the corresponding atomic disorder-order has been ignored in composited systems. We demonstrate examples of GeTe/SnTe compositing for tuning CuInTe2 TE properties. Evidences of increased short-range order and nanoclusters with local chemical order are presented via synchrotron X-ray pair distribution function and scanning transmission electron microscopy. Specifically, GeTe/SnTe compositing within CuInTe2 enhances short-range order. Nanodomains of CuInTe2(GeTe)x are accompanied by a significant atomic-intensity fluctuation that intensifies the scattering of phonons. In contrast to CuInTe2(GeTe)x, nanoclusters with local chemical order are observed in CuInTe2(SnTe)y, accompanied by a weak atomic-intensity fluctuation, which provides superior carrier transport channels and power factor for CuInTe2(SnTe)0.01. Ultimately, a maximum thermoelectric figure of merit zT of ∼1.0 is reported for CuInTe2(SnTe)0.01, which is 54 % greater than that of pristine CuInTe2, and higher than the 0.86 for CuInTe2(GeTe)0.01. This work demonstrates new disorder-order insights that reveal the mysterious roles of compositing for tuning TE transport.

16.48% Efficient solution-processed CIGS solar cells with crystal growth and defects engineering enabled by Ag doping strategy

Solution-processed Cu(In,Ga)Se2 (CIGS) solar cells suffer from serious carrier recombination and power conversion efficiency (PCE) loss because of the poor film properties and easy formation of defects. Herein, we propose Ag&Se co-selenization strategy to enhance the crystallization and passivate harmful defects of the CIGS films. The formation of Ag-Se phase during the selenization process enables the formation of large grains and suppresses the deep level defects. It is found that Ag doping can enlarge the depletion region width, lower the Urbach energy and prolong the carrier lifetime. As a result, a champion solution-processed CIGS solar cell presents a high efficiency of 16.48% with the highly improved open-circuit voltage (VOC) of 662 mV and fill factor (FF) of 75.8%. This work provides an efficient strategy to prepare high quality solution-processed CIGS films for high-performance CIGS solar cells.

Cascaded H-bridge power carrier communication method based on harmonic injection

Abstract Scaded H-bridge inverter systems are widely used, but there are complex communication problems between multiple module communications. In this paper, a power carrier communication method injecting the third harmonic is proposed for a single-phase cascaded H-bridge system. The third harmonic is superimposed on the SPWM sinusoidal waveform as a modulating signal and demodulated from the acquired current signals by means of DQ conversion. The baseband input signals are directly observed from the Id and Iq signals. There is no need to add additional communication lines. The method is simple and reduces costs.

Dual microwave frequency modulation of the VCSEL injection current for a CPT-based atomic clock.

Previously, we have proposed a method to control the emission spectrum of the vertical-cavity surface-emitting laser (VCSEL) with the synchronized modulation of the injection current at single and doubled frequencies. In this work, the above method is used to improve the metrological characteristics of the coherent population trapping (CPT) resonance in 87Rb. The dual-frequency (DF) modulation reduces the carrier power and suppresses the light shift of the resonance frequency, if it is unattainable with the single-frequency modulation. In addition, a higher resonance contrast is achieved by equalizing the powers of the resonant components of the spectrum.

Economic and risk based optimal energy management of a multi-carrier energy system with water electrolyzing and steam methane reform technologies for hydrogen production

This paper proposes stochastic programming to optimal economic scheduling problems of a sustainable integrated energy system with renewable resources including power, natural gas, and hydrogen carriers. Hydrogen is considered a byproduct of electrical power and natural gas carriers using water electrolysis and steam methane reform process technologies. The main objective is to minimize the operation and emission costs while addressing uncertainties of electric/heating/cooling demands, electricity price, and renewable generation using scenario-based stochastic programming. To achieve a risk-hedging strategy, downside risk constraints are involved to minimize the risky scenarios portfolio. The whole problem is modeled as mixed-integer linear programming in GAMS optimization software. The analysis revealed that the expected operation cost without DRC is $ 577.52 and the expected risk-in-cost value for risky scenarios is $ 470.7. However, a conservative decision for reaching zero risk is costly and increases the expected cost up to $ 2901.1, which is not economically viable. A modest decision-making strategy compromises the cost and risk values where for decreasing the risk-in-cost to $ 288.7 (36.8%), the expected cost increased by to $1010.39 (75.95%). Moreover, the risk-averse decision-maker lowers the power sold to the grid, increases the use of water electrolyzing instead of the SMR process to reduce the environmental charges, and tries to increase flexibility with the help of hydrogen and battery storage.

Principles, mechanism, and identification of S‐scheme heterojunction for photocatalysis: A critical review

AbstractSemiconductor photocatalysis has been extensively used in the degradation of pollutants and the production of hydrogen fuel. The main drawback in the application of semiconductor photocatalysis is the rapid recombination of charge carriers. Several strategies have been applied to improve charge carrier separation to preserve them for imparting in photocatalytic reactions. Among the modifications that are made in the photocatalytic systems, the construction of different types of heterostructures, including type II, Z‐scheme, p–n junction, and Schottky junction, has received great attention. Recently, emerging S‐scheme heterojunctions have been shown to be able to preserve powerful charge carriers for photocatalytic reactions, which is not the case in other heterostructures. In this review, principles and mechanisms of charge transfer in S‐scheme heterostructures are discussed, and important semiconductors that have been used in the construction of this type of heterojunctions are reviewed. Methods for identification of S‐scheme heterojunction, challenges, and prospects have been addressed.

Inducing Long Lasting B Cell and T Cell Immunity Against Multiple Variants of SARS-CoV-2 Through Mutant Bacteriophage Qβ-Receptor Binding Domain Conjugate.

More than 3 years into the global pandemic, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a significant threat to public health. Immunities acquired from infection or current vaccines fail to provide long term protection against subsequent infections, mainly due to their fast-waning nature and the emergence of variants of concerns (VOCs) such as Omicron. To overcome these limitations, SARS-CoV-2 Spike protein receptor binding domain (RBD)-based epitopes are investigated as conjugates with a powerful carrier, the mutant bacteriophage Qβ (mQβ). The epitope design is critical to eliciting potent antibody responses with the full length RBD being superior to peptide and glycopeptide antigens. The full length RBD conjugated with mQβ activates both humoral and cellular immune systems in vivo, inducing broad spectrum, persistent, and comprehensive immune responses effective against multiple VOCs including Delta and Omicron variants, rendering it a promising vaccine candidate.