- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Novel High Gain, High Efficiency DC–DC Converter Suitable for Solar PV Module Integration With Three-Phase Grid Tied Inverters
摘要： This paper proposes a novel configuration for high gain, high efficiency dc–dc converter comprising a single switch, two intermediate capacitors, and a coupled inductor for low voltage solar PV module fed applications. The high voltage gain is achieved by charging the intermediate capacitors through the coupled inductor in parallel and discharging in series. In a two winding coupled inductor, considered in the presented work, maximum two intermediate capacitors can be integrated with the secondary winding. A passive lossless clamped circuit is also provided in the converter, which recovers the leakage energy to improve the efficiency and alleviate large voltage spike. The structure of the circuit is such that the power device voltage stress is reduced thereby increasing the efficiency. The maximum power point tracking at various irradiation levels is implemented in the proposed converter. Laboratory prototype of a 300-W system with 30–45-V input and 700-V output was built to validate the theoretical claims. All the detailed analysis, simulation, and experimental waveforms are presented. A maximum converter efficiency of around 95% is achieved.
关键词： maximum power point tracking (MPPT),switched capacitor,solar PV,coupled inductor,dc micro-grid,step-up,high efficiency,3-φ inverter,low voltage,high gain,dc–dc converters
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD) - Austin, TX, USA (2018.9.24-2018.9.26)] 2018 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD) - Dynamical space partitioning for acceleration of parallelized lattice kinetic Monte Carlo simulations
摘要： A new dynamical space partitioning method is presented in a parallelized lattice kinetic Monte Carlo (kMC) simulator to overcome the loss of parallel efficiency found in other parallelized kMC simulators. The dynamical partitioning of the simulation cell allows better load balancing through all threads hence reducing time consuming events during the simulation. The new method is evaluated against both hypothetical and real cases. In both cases, minimal differences between serial and parallelized simulations are found. In real cases, other code optimizations may be needed to further improve the parallel efficiency.
关键词： shared memory,stochastic,nano-scale,FinFET,kMC,parallelization efficiency,OpenMP
更新于2025-09-23 15:22:29
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[IEEE 2018 14th International Conference on Advanced Trends in Radioelecrtronics, Telecommunications and Computer Engineering (TCSET) - Lviv-Slavske, Ukraine (2018.2.20-2018.2.24)] 2018 14th International Conference on Advanced Trends in Radioelecrtronics, Telecommunications and Computer Engineering (TCSET) - New high-efficiency material for acoustooptic modulators. Anisotropy of piezooptic effect in TGS crystals
摘要： The photoelastic characteristics of high-efficiency acoustooptic materials of triglycine sulfate monoclinic syngony were investigated. The anisotropy of the piezooptic coefficients of triglycine sulfate crystals was studied by the method of general and indicative surfaces. The piezooptic interaction geometry characterized by the maximum value of the acoustooptic figure-of-merit of this crystal is in order higher than the same value in other crystals used in the IR acoustooptic devices.
关键词： anisotropy,monoclinic syngony,acoustooptic efficiency,piezooptic coefficients,triglycine sulfate,piezooptic effect
更新于2025-09-23 15:22:29
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[IEEE 2018 International Ural Conference on Green Energy (UralCon) - Chelyabinsk (2018.10.4-2018.10.6)] 2018 International Ural Conference on Green Energy (UralCon) - Development of Effective Device for Protection of Solar Modules from Contamination
摘要： This paper considers the problem of the contamination of the solar modules' surface in the industrial megalopolis. It shows the methods of manual and automated cleaning and the characteristics of contaminant's composition. A new device construction for protecting modules from finely divided dust, based on electron-ion technology principles is proposed. It is established that the catch level of dust particles is determined by the Deutsch formula and depends on the electric field voltage, created by the high potential of the precipitation plates. The calculation of catching dust particles efficiency depending on the air flow speed is done. A pulse source scheme of a high-voltage is developed.
关键词： electron-ion technology,contamination,solar modules,dust catching efficiency
更新于2025-09-23 15:22:29
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Fast Splitting Based Tag Identification Algorithm For Anti-collision in UHF RFID System
摘要： Efficient and effective objects identification using Radio Frequency Identification (RFID) is always a challenge in large scale industrial and commercial applications. Among existing solutions, the tree based splitting scheme has attracted increasing attention because of its high extendibility and feasibility. However, conventional tree splitting algorithms can only solve tag collision with counter value equals to zero and usually result in performance degradation when the number of tags is large. To overcome such drawbacks, we propose a novel tree-based method called Fast Splitting Algorithm based on Consecutive Slot Status detection (FSA-CSS), which includes a fast splitting (FS) mechanism and a shrink mechanism. Specifically, the FS mechanism is used to reduce collisions by increasing commands when the number of consecutive collision is above a threshold. Whereas the shrink mechanism is used to reduce extra idle slots introduced by FS. Simulation results supplemented by prototyping tests show that the proposed FSA-CSS achieves a system throughput of 0.41, outperforming the existing UHF RFID solutions.
关键词： FS mechanism,system throughput,anti-collision,UHF,time efficiency,RFID
更新于2025-09-23 15:22:29
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Cu(OH)2 Nanostructures for Dynamic Photodegradation of Methyl Orange under Visible Light
摘要： A new material of Cu(OH)2 nanostructures was prepared using cupric nitrate and sodium hydroxide as raw materials by the chemical precipitation method. The Cu(OH)2 nanostructures were characterized by scanning electron microscope, transmission electron microscopy, infrared spectrometer, and X-ray diffractometer. The results showed that the Cu(OH)2 nanostructures exhibited excellent uniform and dispersion at 40°C. A series of factors was investigated to effect the photocatalytic efficiency of methyl orange (MO), such as the concentration of Cu(OH)2 nanostructures, the reaction time of the Cu(OH)2 nanostructures, the initial concentration of MO, and so on. As a result, the Cu(OH)2 nanostructures exhibited excellent photocatalytic efficiency with the concentration of 20 mg L–1 Cu(OH)2 nanostructures, the initial concentration of MO was 15 mg L–1 and the stirring time was 70 min.
关键词： photocatalytic efficiency,chemical precipitation method,Cu(OH)2 nanostructures
更新于2025-09-23 15:22:29
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A Slow-Wave Structure Optimization with Variable Helix Section Length in STWT Based on CI-NMCSO Algorithm
摘要： A novel slow-wave structure optimization method on Chaos-improved Normal mutation cat swarm optimization (CI-NMCSO) algorithm is proposed. Under the variable helix section length in STWT, the CI-NMCSO combined with 1D CHRISTINE code is used to calculate the best set of pitch distribution and section length with the objective function of electron beam efficiency improvement. Quantum particle swarm optimization (QPSO) and Cauchy mutated cat swarm optimization (CMCSO) algorithms are applied to make performance comparison. Experimental results show that the beam efficiency has been increased by CI-NMCSO from rated value 30% to 45.3%, and the values using CMCSO and QPSO are 41.8% and 36.5%, respectively, the convergence speed of CI-NMCSO is the fastest, only 16 iterations, while CMCSO and QPSO take 19 and 23 iterations, so the performance of CI-NMCSO is better than CMCSO and QPSO on both optimization precision and calculation speed in terms of slow-wave structure optimization, and is also superior to that with equal section length when the helix section length is variable.
关键词： space traveling-wave tube,electron beam efficiency,chaotic transformation,Slow-wave structure,normal mutation cat swarm optimization
更新于2025-09-23 15:22:29
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Accuracy validation of incident photon fluence on detective quantum efficiency in mammography
摘要： X-ray image evaluation is commonly performed by determining the detective quantum efficiency (DQE). DQE is calculated with a presampled modulation transfer function (MTF), incident photon fluence, and digital noise power spectrum (NPS). Accurate evaluation of MTF, incident photon fluence, and NPS is important for precise DQE determination. In this study, we focused on the accuracy of the incident photon fluence in mammography. The incident photon fluence is calculated using the squared signal-to-noise ratio (SNRin^2) value as specified in the International Electrotechnical Commission (IEC) 62220-1-2 report. However, the reported SNRin^2 values were determined using a computer program, and the reported values may differ from those calculated from an X-ray spectrum that is measured with actual mammography equipment. Therefore, we evaluated the error range of reported SNRin^2 values in mammography to assess the accuracy of the incident photon fluence. First, X-ray spectra from various mammography systems were measured with a CdTe spectrometer. Six mammographic X-ray units were used in this study. Second, the SNRin^2 values were calculated from the measured X-ray spectra. The calculated values were compared to the reported values. The results show that the percentage differences between the calculated and reported SNRin^2 values were within -4.1% of each other. The results obtained in this study indicate that the SNRin^2 values provided in the IEC report are a robust and convenient tool for calculating the incident photon fluence for DQE evaluation in mammography.
关键词： Incident photon fluence,CdTe spectrometer,Mammographic X-ray spectroscopy,Detective quantum efficiency
更新于2025-09-23 15:22:29
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Benefits, problems and challenges of plant factories with artificial lighting (PFALs): a short review
摘要： The benefits and problems to be solved and challenges for plant factories with artificial lighting (PFALs) are discussed. The benefits include high resource-use efficiency, high annual productivity per unit land area, and production of high-quality plants without using pesticides, regardless of weather. A major problem to be solved is high initial investment and operation costs. Challenges for the next-generation smart PFALs include the introduction of advanced technologies such as artificial intelligence with the use of big data, genomics and phenomics (or methodologies and protocols for noninvasive measurement of plant-specific traits related to plant structure and function).
关键词： resource-use efficiency (RUE),cultivation system module (CSM),standardization,smart LED lighting system,annual productivity,artificial intelligence,phenotyping
更新于2025-09-23 15:22:29
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Tailor-made PL-UC-C3 nanoparticles for fluorescence/computed tomography imaging-guided cascade amplified photothermal therapy
摘要： Development of the burgeoning number of photothermal therapy (PTT) agents has drawn a huge amount of interest, since PTT treatment is a powerful and effective alternative to traditional treatments. Optimal PTT agents should integrate some essential preconditions including negligible systemic toxicity, deep penetration into tumor tissues, and maximum laser energy absorbance. Unfortunately, only few of the PTT agents reported could meet all of the above mentioned conditions. Here, we report a brand new PTT agent through the encapsulation of NaGdF4:Yb,Tm@NaGdF4:Yb (UCNPs) and an organic compound (C3) into poly-e-caprolactone-polyethylene-polyglycol (PCL-PEG) (PL-UC-C3 NPs). UCNPs as an up-conversion material and C3 as a PTT agent both feature low cytotoxicity, and most importantly, UCNPs with superior conversion efficiency could efficiently absorb the energy of a 980 nm laser, transform the near-infrared laser light into visible light, and translate the palingenetic visible light to C3. The usage of a 980 nm laser ensures a deeper penetration and lower energy, while the highly efficient absorption and transformation process confers a cascade amplified hyperthermia for tumor treatment. In this regard, our research provides a powerful and robust breakthrough for florescence/computed tomography imaging-guided PTT treatment, lighting up the clinical application in cancer treatment.
关键词： photothermal therapy,excellent photothermal stability,PCL-PEG,high heat conversion efficiency,up-conversion
更新于2025-09-23 15:22:29