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This article proposes an adaptive model-free deadbeat predictive current control (MF-DPCC) algorithm for achieving high-performance current control of non-contact integrated permanent magnet vernier motors (NIPMVMs). To address the issue that traditional extended state observer-based deadbeat predictive control (ESO-DPCC) still relies on motor models and parameters, an ultralocal model is introduced to design a model-free current controller. Furthermore, to address the issue that initial gain of the controller depends on the inductance parameter, a gain-adaption algorithm based on the deadbeat characteristic is proposed. In addition, considering the effect of dead-time, a dual-amplitude signal with extremely low duty and amplitude levels has been adopted to improve the adaptive precision of the gain and to achieve deadbeat control of NIPMVMs. The validity of the proposed MF-DPCC is confirmed through experiments conducted on an NIPMVM platform. [ABSTRACT FROM AUTHOR]

In this article, a stator flux oriented sensorless control method is proposed for interior permanent magnet synchronous motor (IPMSM) drives based on the direct torque and flux control (DTFC) and pseudo-random high-frequency signal injection (PR-HFSI) in the zero-low speed range. The DTFC for IPMSMs is introduced briefly and the conventional high-frequency signal injection (HFSI) method, which requires an additional transformation, is also introduced. Then the stator flux oriented PR-HFSI is proposed comprising injection mode and rotor observation, with the aim of noise reduction and easy implementation. Furthermore, the high-frequency noise in HFSI and the mechanisms of noise suppression in PR-HFSI are analyzed based on current spectrums. Meanwhile, the optimal noise reduction frequency combination of n kinds frequency injections is also analyzed. Finally, the performance of the proposed stator flux oriented PR-HFSI method is confirmed with experiments on a 60 kW IPMSM test bench. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDHs) with abundant accessible active sites are promising electrode materials for hybrid supercapacitor (HSC) due to their ultrahigh theoretical capacitances. However, the structural agglomeration of LDH leads to poor rate capability and durability. Herein, we construct a diffusion-controlled interface in hierarchical architecture of metal-organic framework (MOF) HKUST-1@cobalt-nickel LDH (denoted as HKUST-1@CoNiLDH) through an in situ etching/electro-deposition strategy. The rapid charge transfer and ionic diffusion in HKUST-1@CoNiLDH deliver a remarkable specific capacity of 297.23 mAh·g−1 at 1 A·g−1, superior to mostly reported LDH-based electrodes. More importantly, the as-prepared HKUST-1 @CoNiLDH//activated carbon HSC exhibit a high energy density of 39.8 Wh·kg−1 at a power density of 799.9 W·kg−1 with an outstanding capacitance retention of 90% after 5,000 charge—discharge cycles. The in-depth understanding of the ionic diffusion among the MOF/LDH interfaces will greatly promote the further development of designing and synthesizing high performance energy conversion and storage devices. [ABSTRACT FROM AUTHOR]

Geological studies show that the southern part of Ailaoshan-Red River shear zone (ALSRRSZ) has experienced complex metallogenic processes and multi-stage non-uniform uplifting, called oblique uplifting since the Cenozoic. To detect the deep structure and geodynamic background beneath Daping, Chang'an and other gold and polymetallic deposits in this area, we carried out a high-density short-period seismic array survey in southern Yunnan province. The array used is approximately 240 km long with an interval of 500 m between two adjacent stations. Based on the data collected by the array, we used H-κ stacking and common conversion point (CCP) methods of receiver functions to reveal the fine crustal structure beneath this array, which was located from Lvchun (western end) to the east and ended in Maguan. The three main conclusions are as follows. (1) The average crustal thickness is approximately 37 km and the Vp/Vs ratio is 1.75. However, the thickness and Vp/Vs ratio of the Ailao Mountain are rather greater or higher than those of the western Lanping-Simao Basin and eastern South-China block. These results may indicate that the crust is rich in ferromagnesian minerals or has a thermal fluid anomaly after orogenic movement. (2) There are two obvious inclined interfaces beneath the Ailao Mountain in the mid-upper crust, which suggests that strong deformation occurred there during the orogenic period. Some evidences, such as the weak converted-wave Pms phase from the Moho, low P-wave velocities of the upper mantle, high surface heat flow values, and generally developed hot springs, indicate that a strong crust-mantle interaction exists in the southern segments of the Ailaoshan-Red River shear zone. These interactions include a diapir of mantle-sourced magma (stronger in the east than that in the west), lateral collision from the Indian Plate, and the differential uplift caused by the strike-slip movement of the Red River Fault. All of above deep processes led to the Cenozoic oblique uplifting of Ailao Mountain. (3) By combining the location of the deposits on the surface, characteristics of the average crustal Vp/Vs ratio, hypocenters of the small earthquakes along the research profile, Moho shape, and horizontal variations of the Pms phase amplitudes, we speculate that the Ailaoshan Fault was the upgoing conduit for metallogenic magma and played a significant role in the Cenozoic development of the multiform metal deposits around the Ailao Mountain area. [ABSTRACT FROM AUTHOR]

Surface erosion of wind turbine blades, which are a key component of wind turbines, plays an important role in reducing the output power and service life of the blades. Rain erosion is also detrimental to wind turbine blades. In this review, the research progress on rain erosion is analyzed from the aspects of protection technology, rain erosion mechanism and related rain erosion tests and simulations. A comprehensive protective coating can be obtained by modifying or combining resins with different properties. Investigation of the rain erosion mechanism should consider the influence of the acidity of rain on the organic coatings. The rain erosion device should be more in line with the natural environment, and the dual structure of the substrate composite and surface coating of the blades should be fully considered as well in the rain erosion simulation. [ABSTRACT FROM AUTHOR]

The theoretical calculation of polyaniline tetramers were performed in implicit water solvent medium using the polarizable continuum model with density functional theory. In order to explore the protonation mechanism of polyaniline, the geometry characteristics, charge distribution, frontier molecular orbitals (MOs) and stability of emeraldine base and emeraldine salts in tetramer were investigated by B3LYP/6-31G+(d,p), and the significant increase mechanism of the electrical conductivity of polyaniline upon protonation was researched in detail. It was shown that optimized molecular geometry by protonation doping suggested a tendency towards bipolaron delocalization and a greater π-conjugation proved by bond length alternation and the torsional angles. Furthermore, the NBO of ES3 was distributed equably and should be conducive to the electrical conductivity, the frontier MOs were effectively established, and an electronic transition from HOMO to LUMO+1 is turned out to be a ππ* transition finally. In addition, compared with the computed energies of different emeraldine salt configurations, the bipolaronic lattice was taken for the most stable structure. [ABSTRACT FROM AUTHOR]

Hydrothermal synthesis between (NH )S O and MnSO was carried out to investigate the structure, morphology, and electromagnetic properties of Ni-doped MnO with different doping amounts. The samples were characterized by X-ray powder diffraction (XRD), X-ray fluorescence spectrometry (XRF), scanning electron microscopy (SEM), and vector network analysis. The analysis results revealed that all the final products were α-MnO and few amounts of γ-MnO , and the morphology changed obviously with the increase of the Ni doping amount. The doping of Ni had a certain effect on the electromagnetic properties, and some other properties derived from electromagnetic performances were also investigated, such as dielectric and magnetic loss tangent and microwave-absorbing properties. All the reflection loss (RL) peaks of the final products were moving toward lower frequency with increasing thickness, and with the thickness of 2 mm, the final products all had the maximum effective absorption bandwidth (RL < −10 dB), and the Ni-doped MnO had better reflection loss performance than the undoped MnO in the range of high frequency. [ABSTRACT FROM AUTHOR]

Mn doped with various loadings of nitrogen was prepared by nitridation of a micron α-Mn powder in a flowing ammonia atmosphere at a range of temperatures from 400 to 900 °C. X-ray diffraction (XRD) studies reveal that doping nitrogen content increases as the temperature rising from 400 to 600 °C and then decreases from 600 to 900 °C. A mass of ε-MnN started to form during the heat treatment of α-Mn powder at 900 °C. The structural morphology and grain size of the products were carried out using scanning electron microscope (SEM). Vibration sample magnetometer (VSM) and vector network analyzer (VNA) were employed to investigate the effect of nitrogen doping on the magnetic and electromagnetic performance of the as-synthesized samples. Odd circles were found in the $\varepsilon ^{\prime } - \varepsilon ^{\prime \prime }$ figure, which may come from the interaction between electron charge and applied field. In addition, sphere Landau-Lifshitz-Gilbert (LLG) equation fitting approach is adopted to explain the magnetic resonance of the 900 °C sample. The composite of the 900 °C sample exhibits a wider frequency range for microwave absorption applications than other composites. The sample with a thickness of 7 mm shows two absorption peaks at about 3.6 and 14.48 GHz with the maximum reflection loss of −28.71 dB at 11.18 GHz and the absorption range below −5 dB from 2 to 18 GHz. [ABSTRACT FROM AUTHOR]