High Efficiency Range Research Articles

Torque distribution of distributed drive electric vehicle based on efficiency map of drive system

Abstract In order to optimize the system efficiency of distributed drive electric vehicles, based on the MAP of the efficiency of the drive motor system, the objective function of the optimal efficiency is established, and the problem of the no-load loss of the drive motor is considered. A torque distribution control strategy method considering the no-load loss of the motor is proposed. Then, AVL CRUISE and Simulink are used to establish a joint simulation platform, and a comparative simulation test analysis is carried out under ECE conditions. The simulation results show that the torque distribution strategy considering the loss makes the distributed drive motor work in a relatively high efficiency range. Compared with the torque distribution strategy without considering the loss, the power consumption is reduced by 3.4%, which effectively improves the vehicle economy. The research results can provide a reference for system efficiency optimization of distributed drive electric vehicles.

An High Efficiency Angle and Range Estimation Method for Three-Dimensional Near-Field Sources Based on Higher-Order Cumulants

An High Efficiency Angle and Range Estimation Method for Three-Dimensional Near-Field Sources Based on Higher-Order Cumulants

Deep Mouse Brain Two-Photon Near-Infrared Fluorescence Imaging Using a Superconducting Nanowire Single-Photon Detector Array.

Two-photon microscopy (2PM) has become an important tool in biology to study the structure and function of intact tissues in vivo. However, adult mammalian tissues such as the mouse brain are highly scattering, thereby putting fundamental limits on the achievable imaging depth, which typically reside at around 600-800 μm. In principle, shifting both the excitation as well as (fluorescence) emission light to the shortwave near-infrared (SWIR, 1000-1700 nm) region promises substantially deeper imaging in 2PM, yet this shift has proven challenging in the past due to the limited availability of detectors and probes in this wavelength region. To overcome these limitations and fully capitalize on the SWIR region, in this work, we introduce a novel array of superconducting nanowire single-photon detectors (SNSPDs) and associated custom detection electronics for use in near-infrared 2PM. The SNSPD array exhibits high efficiency and dynamic range as well as low dark-count rates over a wide wavelength range. Additionally, the electronics and software permit a seamless integration into typical 2PM systems. Together with an organic fluorescent dye emitting at 1105 nm, we report imaging depth of >1.1 mm in the in vivo mouse brain, limited mostly by available labeling density and laser properties. Our work establishes a promising, and ultimately scalable, new detector technology for SWIR 2PM that facilitates deep tissue biological imaging.

Energy Management Strategy of Fuel Cell Commercial Vehicles Based on Adaptive Rules

Fuel cell vehicles have been widely used in the commercial vehicle field due to their advantages of high efficiency, non-pollution and long range. In order to further improve the fuel economy of fuel cell commercial vehicles under complex working conditions, this paper proposes an adaptive rule-based energy management strategy for fuel cell commercial vehicles. First, the nine typical working conditions of commercial vehicles are classified into three categories of low speed, medium speed and high speed by principal component analysis and the K-means algorithm. Then, the crawfish optimization algorithm is used to optimize the back propagation neural network recognizer to improve the recognition accuracy and optimize the rule-based energy management strategy under the three working conditions to obtain the optimal threshold. Finally, under WTVC and combined conditions, the optimized recognizer is used to identify the conditions in real time and call the optimal rule threshold, and the sliding average filter is used to filter the fuel cell output power in real time, which finally realizes the adaptive control. The simulation results show that compared with the conventional rule-based energy management strategy, the number of fuel cell start–stops is reduced. The equivalent hydrogen consumption is reduced by 7.04% and 4.76%, respectively.

Amorphous (lysine)2PbI2 layer enhanced perovskite photovoltaics

Passivation materials play a crucial role in a wide range of high-efficiency, high-stability photovoltaic applications based on crystalline silicon and state-of-the-art perovskite materials. Currently, for perovskite photovoltaic, the mainstream passivation strategies routinely rely on crystalline materials. Herein, we have invented a new amorphous (lysine)2PbI2 layer-enhanced halide perovskite. By utilizing a solid phase reaction between PbI2 and lysine molecule, an amorphous (lysine)2PbI2 layer is formed at surface/grain boundaries in the perovskite films. The amorphous (lysine)2PbI2 with fewer dangling bonds can effectively neutralize surface/interface defects, achieving an impressive efficiency of 26.27% (certified 25.94%). Moreover, this amorphous layer not only reduces crystal lattice stress but also functions as a barrier against the decomposition of organic components, leading to suppressed de-structuring of perovskite and highly stable perovskite solar cells.

Effect of blade profile on the hydraulic performance of a double-suction centrifugal pump as turbine based on enstrophy dissipation theory

Pump as turbine (PAT) is widely used in micro hydropower stations and chemical industries as an economical energy recovery device. The special impeller with forward-curved blades can significantly improve the efficiency of PAT and expand its high-efficiency range due to the suitable blade profile, which is more appropriate for PAT's operation mode than the backward-curved blades. To study the influence of the forward blade on a double-suction centrifugal PAT performance, three forward-curved blade schemes with different blade angle conditions are compared with the original backward-curved blade scheme. The three forward-curved blade schemes have the highest efficiency when the inlet angles are 60°, 90°, and 120°, respectively, and the appropriate blade outlet angle. The results showed that the forward-curved blade is suitable for high-flow rate operating conditions in double-suction centrifugal PAT. The PAT with a forward-curved blade impeller has higher efficiency and a broader high-efficiency region than the backward-curved blade impeller. The double-suction centrifugal PAT's main energy loss comes from the impeller's turbulent loss. The forward-curved blade reduces the impeller's turbulence loss and improves the PAT's efficiency at large flow rates. The research in this paper provides a theoretical basis for the design and application of double-suction centrifugal PAT.

Energy efficiency research of propulsion system for series-parallel hybridization of amphibious vehicles

The series-parallel hybrid system has attracted much attention from scholars for its effective integration of the power advantages and operating characteristics of different power sources, which is influenced by international emission regulations, energy-saving and emission reduction policies. As such, a series-parallel hybrid powertrain is introduced to the amphibious vehicle, and an innovative powertrain topology architecture is proposed. Meanwhile, the operation mode and energy efficiency characteristics are investigated during the working process. Firstly, the energy flow simulation model of a series-parallel gas-electric hybrid propulsion system is constructed using a modular modeling approach. Secondly, four operating modes, namely mechanical propulsion, electric propulsion, hybrid propulsion and charging mode, were formulated due to the fact that the propulsion system has multiple forms of power sources in the form of natural gas engine and reversible motor. Meanwhile, the energy flow states were investigated under different operating modes. Meanwhile, a comprehensive investigation of the energy efficiency associated with propulsion, storage and start-up energy was conducted for each specific mode. The results of the research indicated that the energy efficiency of the electric propulsion mode can reach up to 35.15 %, which is the gain from the wide operating range of the motor's high efficiency. The hybrid propulsion mode can obtain the highest energy efficiency of 35.88 %, which fully demonstrates the advantages of coordinating and complementing the two power sources, the natural gas engine and the reversible electric motor. This investigation also provides theoretical and empirical support for optimizing energy matching and formulating energy management strategies.

Dual-mode dual-band symmetrical Doherty power amplifier employing reciprocal gate bias for high-efficiency range enhancement

This article presents an in-depth exploration of the circuit architecture and design approach for broadening the high-efficiency range of dual-mode symmetrical Doherty power amplifiers (DPAs). To enhance performance across a broader spectrum, a modified dual-mode load modulation network (LMN) is introduced, leveraging the reciprocal gate bias configuration to support an expanded high-efficiency range exceeding 6 dB across two distinct operational bands. To corroborate the efficacy of our proposed dual-mode symmetrical DPA architecture, we designed and constructed a prototype power amplifier (PA) utilizing commercially available GaN transistors. The implemented PA demonstrates exceptional performance, achieving two distinct Doherty operation bands, specifically 1.85–2.0 GHz in Mode I and 1.5–1.55 GHz in Mode II. Remarkably, the high-efficiency range is extended to 8 dB in both bands. Furthermore, the drain efficiency achieves levels of 48.5%–51.8% in Mode I and 47.7%–50.4% in Mode II at 8 dB back-off, with a saturated output power exceeding 43 dBm.

Design and Analysis of an Interior Permanent Magnet Synchronous Motor for a Traction Drive Using Multiobjective Optimization

With the development of new energy industries, the demand for the driving range and power quality of electric vehicle (EV) drive systems is growing rapidly. The drive motor is faced with the challenge of continuously improving power density and performance. This paper proposes a multiobjective optimization method for an interior permanent magnet synchronous motor for a traction drive (IPMSMTD). Based on the flat wire winding technology, the multiobjective optimization design of the IPMSMTD is carried out to improve the motor power density and high-efficiency range, reduce the torque ripple, and suppress the electromagnetic vibration and noise. The structure and size equation of the IPMSMTD are described. The mathematical model considering iron losses is established, and the optimization objectives are determined. Based on the genetic algorithm, a multiobjective optimization mechanism of the magnetic pole structure is established. The operation performance of the motor is analyzed by the finite element simulation and efficiency map. In order to ensure the comprehensive operation index of the IPMSMTD, the vibration noise and modal analysis are carried out, which verifies the rationality of the designed motor and the optimization method.

Optimization of immobilized urease enzyme on porous polymer for enhancing the stability, reusability and enzymatic kinetics using response surface methodology

The study examines the immobilization of the urease enzyme on a range of High Internal Phase Emulsion (polyHIPE) materials, assessing characteristics, efficiency, and performance. It also investigates the impact of polyHIPE type, quantity, incubation time, and various parameters on the process and enzyme activity. Surface morphology and functional groups of polyHIPE materials were determined through scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FT-IR) analyses, revealing significant alterations after modification with polyglutaraldehyde (PGA). The maximum immobilization efficiency of 95% was achieved by adding PGA to polyHIPE materials with an incubation period of 15 h. The optimized conditions for immobilized enzyme using a Box-Behnken design (BBD) of response surface methodology (RSM) were as follows: temperature (40.8 °C), pH (7.1) and NaCl concentration (0.007 g/L). Furthermore, the immobilized enzyme demonstrated remarkable reusability, retaining 75% of its initial activity after six cycles, and sustained shelf-life stability, retaining over 40% activity after 10 days at room temperature. Kinetic analyses revealed that immobilized urease exhibited higher affinity for the substrate, but lower rate of substrate conversion compared to the free enzyme. These findings offer valuable insights into optimizing urease immobilization processes and enhancing urease stability and activity, with potential applications in various fields, including biotechnology and biocatalysis.

"Three Musketeers" Enhances Photodynamic Effects by Reducing Tumor Reactive Oxygen Species Resistance.

Photodynamic therapy (PDT) based on upconversion nanoparticles (UCNPs) has been widely used in the treatment of a variety of tumors. Compared with other therapeutic methods, this treatment has the advantages of high efficiency, strong penetration, and controllable treatment range. PDT kills tumors by generating a large amount of reactive oxygen species (ROS), which causes oxidative stress in the tumor. However, this killing effect is significantly inhibited by the tumor's own resistance to ROS. This is because tumors can either deplete ROS by high concentration of glutathione (GSH) or stimulate autophagy to eliminate ROS-generated damage. Furthermore, the tumor can also consume ROS through the lactic acid metabolic pathway, ultimately hindering therapeutic progress. To address this conundrum, we developed a UCNP-based nanocomposite for enhanced PDT by reducing tumor ROS resistance. First, Ce6-doped SiO2 encapsulated UCNPs to ensure the efficient energy transfer between UCNPs and Ce6. Then, the biodegradable tetrasulfide bond-bridged mesoporous organosilicon (MON) was coated on the outer layer to load chloroquine (CQ) and α-cyano4-hydroxycinnamic acid (CHCA). Finally, hyaluronic acid was utilized to modify the nanomaterials to realize an active-targeting ability. The obtained final product was abbreviated as UCNPs@MON@CQ/CHCA@HA. Under 980 nm laser irradiation, upconverted red light from UCNPs excited Ce6 to produce a large amount of singlet oxygen (1O2), thus achieving efficient PDT. The loaded CQ and CHCA in MON achieved multichannel enhancement of PDT. Specifically, CQ blocked the autophagy process of tumor cells, and CHCA inhibited the uptake of lactic acid by tumor cells. In addition, the coated MON consumed a high level of intracellular GSH. In this way, these three functions complemented each other, just as the "three musketeers" punctured ROS resistance in tumors from multiple angles, and both in vitro and in vivo experiments had demonstrated the elevated PDT efficacy of nanomaterials.

The online control method of independent DC microgrid based on virtual hydrogen consumption method

AbstractWith the development of distributed generation and power electronics technology, DC microgrids have made certain progress with their advantages of simple structure, economic efficiency, and easy control. Considering factors such as the geographical location of some residential areas, microgrids with fuel cells that can operate independently are also receiving increasing attention. In this paper, an online control method named virtual hydrogen consumption is proposed based on an independent DC microgrid which solves the problem of electro‐hydrogen conversion successfully. By solving the overall consumption function, the analytical solution is further obtained to realize the online control. Based on the results of RT‐LAB platform, the proposed method can maintain the output of fuel cell system in its high efficiency range with a lower volatility.

Research on Power Optimization for Energy System of Hydrogen Fuel Cell Wheel-Driven Electric Tractor

Hydrogen fuel cell tractors are emerging as a new power source for tractors. Currently, there is no mature energy management control method available. Existing methods mostly rely on engineers’ experience to determine the output power of the fuel cell and the power battery, resulting in relatively low energy utilization efficiency of the energy system. To address the aforementioned problems, a power optimization method for the energy system of hydrogen fuel cell wheel-driven electric tractor was proposed. A dynamic model of tractor ploughing conditions was established based on the system dynamics theory. From this, based on the equivalent hydrogen consumption theory, the charging and discharging of the power battery were equivalent to the fuel consumption of the hydrogen fuel cell, forming an equivalent hydrogen consumption model for the tractor. Using the state of charge (SOC) of the power battery as a constraint, and with the minimum equivalent hydrogen consumption as the objective function, an instantaneously optimized power allocation method based on load demand in the energy system is proposed by using a traversal algorithm. The optimization method was simulated and tested based on the MATLAB simulation platform, and the results showed under ploughing conditions, compared with the rule-based control strategy, the proposed energy system power optimization method optimized the power output of hydrogen fuel cells and power batteries, allowing the energy system to work in a high-efficiency range, reducing the equivalent hydrogen consumption of the tractor by 7.79%, and solving the energy system power distribution problem.

Engineered Multi-Shelled hollow mesoporous organosilica for efficient Pb(II) and Cr(VI) removal

Adsorbents with fast kinetics and high capacity have always been attractive for wastewater treatment. Herein, multi-shelled hollow mesoporous organosilica functionalized by hydroxyphosphatoethyl groups on dual-pore surfaces (P-HMO) is prepared by general one-pot co-condensation. The resulting P-HMO exhibits high hydrophilicity, large surface area and well-developed pore structure, providing P-HMO fast adsorption kinetics (C0 = 320 mg·L-1, equilibrium within 5 min) and ultrahigh adsorption efficiency for Pb(II) and Cr(VI), the adsorption capacity reaches 1056.53 and 869.56 mg·g−1, respectively. Furthermore, P-HMO displays outstanding reusability over 10 adsorption–desorption cycles thanks to the stable framework structure that can resist wear and tear during water treatment. The advantages of long service life, high efficiency and broad pH range make P-HMO promising in industrial water purification.

Synergistic oxidation of humic acid treated by H2O2/O3 activated by CuCo/C with high efficiency and wide pH range

Combination of oxidation processes are one of the most promising humic acid treatment technologies. Single oxidant or even two oxidants in advance oxidation process can hardly achieve satisfactory removal efficiency of refractory organic matter, mainly humic acid, in the treatment process of reverse osmosis concentrates from landfill leachate. To solve this problem, this study investigated the synergistic degradation of Humic acid (HA) using a Cu and Co supported on carbon catalyst (CuCo/C) in a Hydrogen peroxide (H2O2) with ozone (O3) system. The catalyst was characterized by performing SEM, XRD, BET, XPS and FTIR technologies. UV–vis spectra, 3D Excitation Emission Matrix Spectra (3D-EEM) and gas chromatography-mass spectrometry (GC–MS) were applied for exploring degradation mechanism of HA. To further understand the oxidation mechanism, electron paramagnetic resonance (EPR) was used to evaluate the generation of hydroxyl (·OH) and superoxide radicals (O2·-). As a result, CuCo/C catalyst possessed stable catalytic performance for HA degradation with a wide pH range from 5 to 8, while T = 40 °C，catalyst dosage of 2.4 g/L，O3 intake rate of 0.15 g/min and H2O2 dosage of 1.92 mL/L, the degradation rate of total organic carbon (TOC) achieved 40–46.5 mg·L−1min−1. As affirmed by the EPR, ·OH and O2·- were effectively generated with addition of the CuCo/C catalyst. Degradation performance of UV254 proved that the catalytic activity can still be maintained above 95% with removal rate of 82% after 5 cycles reuse. GC-MS shows that the oxidation products mainly consist of amide, benzoheterocyclic ring and carboxylic acid. This work promotes an effective method for degrading HA, which has the potential for satisfactory application in landfill leachate.

A highly sensitive ratiometric fluorescent probe for detecting HSO3−/SO32− and viscosity change based on FRET/TICT mechanism

BackgroundSulfur dioxide (SO2) is a significant gas signaling molecule in organisms, and viscosity is a crucial parameter of the cellular microenvironment. They are both involved in regulating many physiological processes in the human body. However, abnormalities in SO2 and viscosity levels are associated with various diseases, such as cardiovascular disease, lung cancer, respiratory diseases, neurological disorders, diabetes and Alzheimer's disease. Hence, it is essential to explore novel and efficient fluorescent probes for simultaneously monitoring SO2 and viscosity in organisms. ResultsWe selected quinolinium salt with good stability, high fluorescence intensity, good solubility and low cytotoxicity as the fluorophore and developed a highly sensitive ratiometric probe QQD to identify SO2 and viscosity changes based on Förster resonance energy transfer/twisted intramolecular charge transfer (FRET/TICT) mechanism. Excitingly, compared with other probes for SO2 detection, QQD not only identified HSO3−/SO32− with a large Stokes shift (218 nm), low detection limit (1.87 μM), good selectivity, high energy transfer efficiency (92 %) and wide recognition range (1.87–200 μM), but also identified viscosity with a 26-fold fluorescence enhancement and good linearity. Crucially, QQD was applied to detect HSO3−/SO32− and viscosity in actual water and food samples. In addition, QQD had low toxicity and good photostability for imaging HSO3−/SO32− and viscosity in cells. These results confirmed the feasibility and reliability of QQD for HSO3−/SO32− and viscosity imaging and environmental detection. SignificanceWe reported a unique ratiometric probe QQD for detecting HSO3−/SO32− and viscosity based on the quinolinium skeleton. In addition to detecting HSO3−/SO32− and viscosity change in actual water and food samples, QQD could also monitor the variations of HSO3−/SO32− and viscosity in cells, which provided an experimental basis for further exploration of the role of SO2 derivatives and viscosity in biological systems.

Study of residual artificial neural network for particle identification in the CEPC high-granularity calorimeter prototype

Particle Identification (PID) plays a central role in associating the energy depositions in calorimeter cells with the type of primary particle in a particle flow oriented detector system. In this paper, we propose novel PID methods based on the Residual Network (ResNet) architecture which enable the training of very deep networks, bypass the need to reconstruct feature variables, and ensure the generalization ability among various geometries of detectors, to classify electromagnetic showers and hadronic showers. Using Geant4 simulation samples with energy ranging from 5 GeV to 120 GeV, the efficacy of Residual Connections is validated and the performance of our model is compared with Boosted Decision Trees (BDT) and other pioneering Artificial Neural Network (ANN) approaches. In shower classification, we observe an improvement in background rejection over a wide range of high signal efficiency (> 95%). These findings highlight the prospects of ANN with Residual Blocks for imaging detectors in the PID task of particle physics experiments.

Configuration of the Power Reflux Hydro-Mechanical Transmission System

The hydro-mechanical transmission system (HMTS) operates either in power split transmission mode (PSTM) or power reflux transmission mode (PRTM). Although PRTM is often ignored as a transition mode, this study reveals that the HMTS operating in the PRTM can accumulate the power input from the power source in the form of reflux power (in some references, scholars also refer to the reflux power as circulating power), thereby enabling the HMTS to exhibit a similar transmission performance as hydrodynamic transmission systems. Accordingly, this study applies the PRTM to the starting of construction vehicles and refers to the HMTS operating only in the PRTM as the power reflux hydro-mechanical transmission system (PHTS). By analyzing the internal relationship between the configuration and the power flow, transmission characteristics, energy storage mechanism, and energy loss mechanism of the PHTS, the optimal PHTS configuration suitable for construction vehicles was explored. The results indicate that reasonable configurations can enable the PHTS to significantly improve the efficiency of the construction vehicle transmission system, reducing energy consumption while ensuring power performance. Expanding the displacement ratio control range of the hydraulic speed regulation mechanism and combining the PRTM with the PSTM in an orderly manner can widen the high-efficiency range of the vehicle transmission system without increasing the number of vehicle gears.

A Review of the State of the Art of Torque Ripple Minimization Techniques for Permanent Magnet Synchronous Motors

Industrial applications such as automation, robots, and electric vehicles are widely employing permanent magnet synchronous motors (PMSM) due to inherent characteristics such as high torque to power ratio, low maintenance, high efficiency, and wide operating range. However, PMSM drives can suffer from unwanted torque ripples caused by periodic disturbances of the electromagnetic effect. First, this paper analyses the sources of torque ripple in PMSMs. Second, the torque measurement techniques of the PMSM including torque sensors, torque observers, and indirect measurement methods are discussed to highlight their shortcomings. Third, this paper categorizes and summarizes advanced control-based torque ripple minimization (CB-TRM) techniques for the PMSM by critically evaluating their impacts. These CB-TRM techniques actively control the current waveforms to ensure smooth torque generation and mitigate the effects of torque ripples. Finally, the paper concludes by discussing remaining research questions and opportunities for future research on TRM techniques for PMSMs.

Modeling and Control of a PEM Fuel Cell Hybrid Energy System Used in a Vehicle with Fuzzy Logic Method

PEM (Proton Exchange Membrane) fuel cells, which are commonly used in vehicles, are critical for sustainable transportation in the future. In this study, it is aimed to en-hance the system efficiency of the PEM fuel cell and provide fuel economy. To achieve this goal, the hybrid energy system with a PEM fuel cell and battery pack is controlled with two different strategies. The first control strategy is designed using Fuzzy Logic (FL), while the other control strategy is designed with the classical on-off method with the 'Relay' block. Power output of the fuel cell is determined depending on the change in the charging state of the battery pack and the power consumed by the electric vehicle in this study. The aim is to provide that the fuel cell operates in a high-efficiency range and can generate enough power when needed. Vehicle and fuel cell modeling were per-formed in Matlab/Simulink environment. NEDC (New European Driving Cycle) and WLTP (Worldwide Harmonized Light Vehicles Test Procedure) driving cycles were considered and fuel cell efficiency and hydrogen consumption were compared at dif-ferent state of charge values of the battery. The analyses were carried out over long dis-tances by repeating the driving cycles. It was observed that fuzzy logic control provid-ed 11.6% less fuel consumption than classic on-off control in NEDC and WLTP driving cycles repeated five times. The values obtained as a result of the study showed that fuzzy logic control is more advantageous to increase the energy efficiency of fuel cells.