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To enhance the operational efficiency and fault detection accuracy of hydroelectric units, this paper proposes a parallel convolutional neural network model that integrates the Gramian angular summation field (GASF) with an Improved coati optimization algorithm–parallel convolutional neural network (ICOA-PCNN). Additionally, to further improve the model's accuracy in fault identification, a multi-head self-attention mechanism (MSA) and support vector machine (SVM) are introduced for a secondary optimization of the model. Initially, the GASF technique converts one-dimensional time series signals into two-dimensional images, and a COA-CNN dual-branch model is established for feature extraction. To address the issues of uneven population distribution and susceptibility to local optima in the COA algorithm, various optimization strategies are implemented to improve its global search capability. Experimental results indicate that the accuracy of this model reaches 100%, significantly surpassing other nonoptimized models. This research provides a valuable addition to fault diagnosis technology for modern hydroelectric units. [ABSTRACT FROM AUTHOR]

Studies show that sediment erosion is one of the main factors attributing to hydraulic turbine failure. The present paper represents an investigation into acoustic vibration signals generated by the water flow impacting the hydraulic turbine runner under three different operating conditions. Collected signals were denoised using the ICEEMDAN-wavelet threshold method, and then the spectral characteristics and sample entropy characteristics of the signals for the three operating conditions were analyzed. The results show that when clean water flows through the hydraulic turbine, the sample entropy reaches its smallest values and the dominant frequency component in the spectrogram is 59.39 Hz. When transitioning from clean water to the flood flow containing 2–4 mm sediment particles, the sample entropy is increasing and a high-frequency component higher than 59.39 Hz becomes the prominent frequency of the spectrogram. Meanwhile, the formation of high-frequency components increases with the sand-containing particle size. Based on the spectral characteristics and sample entropy characteristics of the acoustic vibration signals under different operating conditions, it can provide a reference for the sand avoidance operation of the hydraulic turbine during flood season. In addition, it provides a supplement to the existing hydraulic turbine condition's monitoring systems and a new avenue for subsequent research on early warning of hydraulic turbine failure. [ABSTRACT FROM AUTHOR]

In today's human society, diesel generators (DGs) are widely applied in the human energy and electricity supply system due to its technical, operational, and economic advantages. This paper proposes an intelligent nonlinear H 2 / H ∞ robust controller based on the chaos particle swarm gravity search optimization algorithm (CPSOGSA), which controls the speed and excitation of a DG. In this method, firstly, establish the nonlinear mathematical model of the DG, and then design the nonlinear H 2 / H ∞ robust controller based on this. The direct feedback linearization and the H 2 / H ∞ robust control theory are combined and applied. Based on the design of the integrated controller for DG speed and excitation, the system's performance requirements are transformed into a standard robust H 2 / H ∞ control problem. The parameters of the proposed solution controller are optimized by using the proposed CPSOGSA. The introduction of CPSOGSA completes the design of an intelligent nonlinear H 2 / H ∞ robust controller for DG. The simulation is implemented in MATLAB/Simulink, and the results are compared with the PID control method. The obtained results prove that the proposed method can effectively improve the dynamic accuracy of the system and the ability to suppress disturbances and improve the stability of the system. [ABSTRACT FROM AUTHOR]

Low-dimensional tin-based halide perovskites are considered as eco-friendly substitutions of the iconic lead-based perovskites to host the potential as optoelectronic materials. However, a fundamental understanding of the structure-property relationship of these Sn(II)-based hybrids is still inadequate due to the limited members of this material family. To our knowledge, there is still lack of reports on a series of Sn(II)-based halide perovskites with the same organic cation but covering chloride, bromide, and iodide. In this work, three new halide perovskites TMPDASnX 4 (X = Cl, Br, I) (TMPDA = N,N, N ', N '-tetramethyl-1,4-phenylenediamine) are successfully synthesized, which provide the ideal paradigm to study the halogen-dependent evolution of the structure and properties of Sn(II)-based hybrid perovskites. Despite sharing the same monoclinic lattice ( P 2 1 / m space group), it is demonstrated that TMPDASnCl 4 adopts a one-dimensional structure composed of a five-coordinated pyramid configuration due to an extremely long Sn···Cl distance, while the typical two-dimensional motif is still maintained in TMPDASnBr 4 and TMPDASnI 4 . The ambient stability is declined in the order from chloride to bromide and then to iodide. TMPDASnCl 4 exhibits a broad-band bluish-white-light emission (centered at 515 nm, full width at half-maximum (fwhm) = 193 nm) with the Commission Internationale de l' Elairage (CIE) coordinates as (0.29, 0.34). Further, the correlated color temperature and color-rendering index were determined as 7617 K and 80.5, respectively. Based on the synthesis of new crystals, our work sheds light on the composition-structure-property relationship of hybrid Sn(II)-based halide perovskites., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

The computer information technology that has penetrated into every aspect of our lives, can not only assist the screening of drugs, but also simulate the effect of drugs. At present, computer-aided technologies have been used to screen aptamers, which play an important role in improving the screening efficiency and screening high affinity binding aptamers. This review summarized the screening methods of aptamers through computer-aided sequence evaluation, structural analysis and molecular docking.