Accurate parameter extraction of photovoltaic (PV) models is crucial for simulation and optimization but remains challenging due to their nonlinear and multi-modal characteristics. To address this, this paper proposes an enhanced metaheuristic algorithm named the Quasi-Oppositional learning and Differential Crossover enhanced Mayfly Optimization Algorithm (QODC-MOA). The algorithm incorporates two pivotal mechanisms: first, a quasi-oppositional learning strategy is employed both for population initialization and during the iterative update process to enhance diversity and help escape local optima; second, the original arithmetic crossover is replaced by a differential crossover operator to strengthen global exploration and information exchange. Furthermore, an adaptive linearly decreasing gravity coefficient is introduced to dynamically balance exploration and exploitation across different evolutionary stages. Extensive experiments on parameter extraction for single- and double-diode PV models demonstrate that the proposed QODC-MOA achieves significantly higher accuracy, reliability, and convergence speed than both the basic mayfly algorithm and other state-of-the-art meta-heuristic optimizers.
The deterioration of transistor performance due to carrier scattering when the thickness of silicon is reduced below a few nanometers is one of the major concerns in silicon-based electronics. Atomically thin two-dimensional transition metal dichalcogenides (TMDCs) do not suffer from this problem and are thus appealing candidates for next generation transistors. To speed up the development of TMDCs for device applications, a fast, noninvasive, and reliable technique to measure the electrical properties on the micrometer scale is paramount. Here, we use multi-probe cantilevers with micrometer pitches to non-invasively probe the electronic properties of mono-, bi-, and trilayer molybdenum disulfide samples. We extract field-effect mobilities in the range from 2.7 to 16.3 cm2 V−1 s−1. Furthermore, atomic force microscopy images taken after the transport measurements reveal that landing damage from the multi-probe cantilever to the sample can be avoided, provided that the landing of the probe is gentle and the drain–source currents are limited.
Direct-drive wave energy conversion systems based on permanent-magnet linear synchronous generators offer a robust path for ocean energy harvesting but face reliability challenges in marine environments where mechanical sensors are prone to failure. This paper presents a sensorless electromagnetic force execution strategy ensuring high-fidelity power capture without physical transducers. To address observability degradation at low-speed reciprocating motion, we propose a reverse-region-gated dual-time-scale amplitude modulation scheme for high-frequency square-wave injection, adaptively boosting signal strength specifically at stroke reversals while maintaining nominal efficiency elsewhere. Furthermore, to reject residual disturbances from estimation uncertainties and cross-coupling effects, a composite current tracking controller integrates a standard proportional-integral loop with a super-twisting disturbance observer (STDO). The STDO provides practical finite-time convergence to a boundary layer and chattering-alleviated compensation precisely when the system enters weak-observation zones. Experimental validation on an emulation platform under irregular wave profiles confirms that the proposed method significantly suppresses position drift and minimizes current tracking deviations, demonstrating viability for maintenance-free wave energy converters.
Specular reflections, structural slots, and weak damage boundaries complicate image-based measurement of erosion on vacuum interrupter contacts. Methods relying primarily on pixel intensity or chromaticity provide limited spatial context for distinguishing weak erosion boundaries from reflection-induced appearance variations, motivating a calibrated measurement workflow that combines local detail with contextual features. This study develops a workflow that adapts the visual saliency model MBDNet to binary erosion segmentation and physical-area estimation. Contrast enhancement and valid-metal masking are combined with multiscale feature extraction and a weighted segmentation loss. The predicted erosion region is quantified using image-scale calibration. In the preliminary evaluation, the proposed model attained an intersection over union of 0.887 and a relative area error of 4.31% against image annotations. Reference-area comparisons at four interruption counts gave relative differences of 3.40%–4.20%, with predictions exceeding the reference values in all four cases. Square reference specimens with side lengths of 1–10 mm gave a mean area error of ∼1.71%. The distinct results for contact surfaces and reference specimens show why geometric calibration and erosion delineation must be evaluated separately. Total estimated erosion area increased from 16.38 to 145.32 mm2 between the reported 50- and 200-interruption conditions. The workflow provides a basis for laboratory measurement of visible contact-surface damage; broader use requires validation on independent contacts.
Emission characteristics of coaxial KrCl excilamp for production of UV using CCl4 as a chlorine donor are investigated experimentally. Excilamp is based on DBD and is driven by the sinusoidal voltage with amplitude of 3.7–4 kV at a frequency of 40 kHz. The emission characteristics of Kr/CCl4 excilamps were compared with those of Kr/Cl2. The results showed that the intensity of 222 nm [KrCl*(B-X)] was about 6% higher compared to Kr/Cl2 excilamps, while the intensities of other wavelength were about 2%, 4.3%, and 2% lower, respectively. The effects on the radiation intensity of the total pressure and CCl4 concentration are presented. The maximum value of the 222 nm radiation intensity was obtained for mixtures Kr:CCl4 = 200:1. When the plasma is steady, intensity was 103 μW/cm2. The experimental results will be contributed to the fabrication and application of KrCl excilamps for UV light sources using halide (CCl4).
