15 research outputs found
MPPT control technology based on the GWO-VINC algorithm
It is a challenging task to accurately track the global maximum power point (GMPP) in a changing environment in widely used photovoltaic (PV) systems. So far, a variety of maximum power point (MPP) tracking algorithms have been used in solar PV power systems. The classical algorithm is simple and fast to track the speed effectively in a constant environment, but it can get stuck at an extreme point in a variable environment. In this paper, the variable-step incremental conductance (VINC) method is combined with the gray wolf optimization (GWO) algorithm. Firstly, GWO conducts a global search. When the search reaches the area near GMPP, the next step of the search process is carried out based on the iteration number conditions of GWO. Enter the search process of VINC and determine whether the current search process is on the left or right side of the vertex based on the current search value. And adjust the duty cycle during the VINC search process using different variable step size methods based on the left and right sides, and finally accurately locate the GMPP value. To verify the robustness of the proposed algorithm, simulation, and experimental comparisons were conducted between the proposed method in the article and GWO and VINC. The tracking efficiency of static shadows, simulated dynamic shadows, and experimental static and dynamic shadows is 99.80%, 98.82%, 99.43%, and 98.51%, respectively. The tracking time of simulation and experiment is 46.49% and 89.34% faster than GWO and VINC technologies, respectively. The results show that compared with the GWO and VINC methods, the proposed method has improved tracking speed and efficiency. Moreover, compared with the method that combines the two intelligent algorithms, this method has fewer algorithm parameters, a simple calculation process, lower complexity, lower hardware requirements, and better actual implementation performance
Evidence of strong and mode-selective electron–phonon coupling in the topological superconductor candidate 2M-WS 2
The interaction between lattice vibrations and electrons plays a key role in various aspects of condensed matter physics — including electron hydrodynamics, strange metal behavior, and high-temperature superconductivity. In this study, we present systematic investigations using Raman scattering and angle-resolved photoemission spectroscopy (ARPES) to examine the phononic and electronic subsystems of the topological superconductor candidate 2M-WS2. Raman scattering exhibits an anomalous nonmonotonic temperature dependence of phonon linewidths, indicative of strong phonon–electron scattering over phonon–phonon scattering. The ARPES results demonstrate pronounced dispersion anomalies (kinks) at multiple binding energies within both bulk and topological surface states, indicating a robust and mode-selective coupling between the electronic states and various phonon modes. These experimental findings align with previous calculations of the Eliashberg function, providing a deeper understanding of the highest superconducting transition temperature observed in 2M-WS2 (8.8 K) among all transition metal dichalcogenides as induced by electron–phonon coupling. Furthermore, our results may offer valuable insights into other properties of 2M-WS2 and guide the search for high-temperature topological superconductors
Strategies and methods for fabricating high quality metal halide perovskite thin films for solar cells
With the development of human society, the problems of environmental deterioration and energy shortage have become increasingly prominent. In order to solve these problems, metal halide perovskite solar cells (PSCs) stand out because of their excellent properties (i.e., high optical absorption coefficient, long carrier lifetime and carrier diffusion length, adjustable band gap) and have been widely studied. PSCs with low cost, high power conversion efficiency and high stability are the future development trend. The quality of perovskite film is essential for fabricating PSCs with high performance. To provide a full picture of realizing high performance PSCs, this review focuses on the strategies for preparing high quality perovskite films (including antisolvent, Lewis acid-base, additive engineering, scaleable fabrication, strain engineering and band gap adjustment), and therefore to fabricate high performance PSCs and to accelerate the commercialization
A case report of rare complication of brucellosis infection: myocarditis and pneumonitis
The involvement of cardiovascular or respiratory complications in cases of brucellosis are extremely rare. Herein, a case of myocarditis and pneumonia with pericardial effusion, pleural effusion and biliteral pleural thickening with pleural adhesion in a 35-year-old female patient, is described. Using next-generation sequencing, the patient was differentially diagnosed with Brucella -related myocarditis and pneumonitis, and treatment with oral doxycycline, rifampicin, and trimethoprim/sulfamethoxazole, along with intravenous gentamycin, was commenced. Following treatment, the patient was clinically improved. When a patient with brucellosis presents with chest pain, clinicians should be aware of this clinical manifestation. Next-generation sequencing may be used to identify pathogens and provide insights into the disease when appropriate cultures are negative
Optimization Strategy of Hybrid Configuration for Volatility Energy Storage System in ADN
This study aims to address the issues of volatile energy access to the active distribution network (ADN), which are the difficulty of frequency regulation, the increased voltage deviation of the ADN, the decrease in operational security and stability, etc. In this study, a two-stage majorization configuration model is established to identify and understand how volatility energy affects a hybrid energy storage system (HESS). The ADN and HESS with lead-acid batteries and supercapacitors (SC) are examined using day forecast data for wind, solar, and load. In this planning stage, the integrated cost, network loss, and node voltage deviation are considered as optimal objectives in a multi-objective optimization model, while the revised multi-objective optimization particle swarm approach is used to solve the initial value of capacity configuration. In the operation stage, optimizing objectives like wind output power fluctuations, the frequency deviation of HESS is used to solve the modified value of the configuration capabilities of the SC, and the output of different types of units in ADN is further optimized by the quantum particle swarm with the addition of a chaotic mechanism. The simulation study is conducted to determine the best configuration result based on case 33 node examples, and the simulation results demonstrate the model’s viability
Solid-to-Solid Crystallization of Organic Thin Films: Classical and Nonclassical Pathways
The solid-to-solid
crystallization processes of organic molecules
have been poorly understood in view of the complexity and the instability
of organic crystals. Here, we studied the crystallization of a π-conjugated
small molecular semiconductor, bis-(8-hydroxyquinoline) copper (CuQ<sub>2</sub>), by annealing the thin films at different temperatures.
We observed a classical film-to-nanorods crystallization at 80 °C,
a coexistence of classical and nonclassical nucleation and particle
growth at 120 °C, and a nonclassical crystal growth at 150 °C.
We found that the growth of the crystals followed the following processes:
particle nucleation, particle growth, particle migration, nondirectional
particle attachment, and structure reconstruction. We notice that
the growth of CuQ<sub>2</sub> particles follows an outside-to-inside
process. More interestingly, our experiments suggest that the submicron
CuQ<sub>2</sub> particles are able to migrate dozens of micrometers
at 150 °C