Offshore wind turbines operating under sheared-inflow conditions of the marine atmospheric boundary layer often experience increased fluctuations in aerodynamic thrust. This study investigates the aerodynamic efficiency of a dual-suction flow jet (D-SFJ) flow control under marine wind conditions. The device comprises two suction slots on the suction side and two injection slots near the trailing edge on the pressure side, and is implemented on the IEA 15 MW reference turbine. Based on the Coupled Ocean Atmosphere Wave Sediment Transport (COAWST) model, the spatial-temporal evolution of wind-wave-current is accurately simulated. Subsequently, leveraging the numerical sheared-inflow profile derived from mesoscale models, a series of three-dimensional unsteady microscale simulations is conducted to analyze the aerodynamic forces of a wind turbine under both constant and time-varying jet scenarios. The findings confirm that the COAWST model has superior capability in predicting the ocean wind speed by considering air-sea interaction, with a Pearson's correlation coefficient of 0.85 at 198 m. For the D-SFJ control device with varying jet strength, the thrust fluctuation, the thrust fluctuation relative to that of the wind turbine without D-SFJ control is reduced, and the net aerodynamic power can be raised by 2.53

This study presents an integrated experimental and computational fluid dynamics investigation of wake interactions between two tandem-aligned horizontal-axis tidal turbines. Through high-precision acoustic Doppler velocimetry measurements and blade-resolved simulations using the shear stress transport-partially averaged Navier–Stokes (SST-PANS) turbulence model, the hydrodynamic performance and wake dynamics are systematically analyzed under inter-turbine spacings of 6D (six times the rotor diameter) and 8D (eight times the rotor diameter). Results demonstrate that the downstream turbine experiences a 45% reduction in optimal power output at 6D spacing, driven by intensified velocity deficits (up to 75%) and turbulence intensity (25%) within the upstream wake. The SST-PANS model, validated against experimental data with less than 8% discrepancy in wake velocity and turbulence predictions, effectively resolves anisotropic turbulence effects, including tip vortex breakdown and shear layer evolution. An observation of power spectral density slope transition from −5/3 (single) to −11/3 (tandem) highlights distinct turbulence-driven power fluctuations. These findings recommend a minimum 8D spacing to balance energy extraction and wake recovery, advancing turbulence modeling frameworks for cost-effective tidal farm design.

The catalytic deactivation caused by SO2 impurity remains a great challenge in the efficient destruction of industrial chlorinated volatile organic compounds (CVOCs). Herein, a Ce-Mn@ZrO2-SO42- catalyst with a Ce-O-Mn active system and ZrO2-SO42- protective layer was rationally engineered, which exhibits superior activity for chlorobenzene (CB) and SO2 cotreatment at 228 °C, achieving 90% CB mineralization─over 80% higher than that of the CeO2 catalyst. In situ characterization and theoretical calculation results reveal that the SO42- groups not only inhibit the adsorption of SO2 molecules through steric hindrance and electrostatic repulsion but also act as the Brønsted acid sites (BAS) to promote C-Cl cleavage of chlorobenzene (CB) and accelerate the desorption of Cl radicals as inorganic chlorine (HCl and Cl2). Additionally, the Ce-O-Mn structure accelerates electron transfer between active sites, enhances the strength of Lewis acid sites (LAS), and weakens the lattice oxygen stability to generate oxygen vacancies (Ov). These features collectively result in the excellent chlorine and sulfur resistance of the Ce-Mn@ZrO2-SO42- catalyst. Compared to CeO2 and Ce-Mn@ZrO2, chlorinated and sulfated byproducts respectively decrease by 7.9 and 2.7 times in the presence of 100 ppm SO2. This study provides a feasible and promising strategy for engineering efficacious non-noble metal catalysts toward CVOCs' deep purification with SO2 impurity, showcasing substantial economic and environmental benefits.

Most existing parameter identification methods are developed under stable conditions, which are inevitably vulnerable under nonstationary conditions, such as variable load or variable speed conditions. In this paper, a novel parameter identification method of permanent magnet synchronous motor (PMSM) servo systems is proposed, by which the PMSM parameters and voltage source inverter (VSI) nonlinearity can be identified under nonstationary conditions. Firstly, a novel dynamic average model is established, which only focuses on the dynamic average values of nonstationary vibration signals, instead of their instantaneous sampling values. Due to the neglect of disturbances such as high- frequency components and measurement noise, the parameter identification method based on this model has strong robustness and stability under nonstationary conditions. Secondly, according to the identifiability analysis and proposed information extracted method, the dynamic average values which make the model full rank can be extracted from the nonstationary vibration signals. Finally, the parameters in the model are solved by multi-innovation least squares (MILS) algorithm. The proposed parameter identification method is tested on a laboratory PMSM servo system. The experimental results demonstrate that this method can accurately identify parameters under various nonstationary conditions.

The catalytic deactivation caused by SO2 impurity remains a great challenge in the efficient destruction of industrial chlorinated volatile organic compounds (CVOCs). Herein, a Ce-Mn@ZrO2-SO42- catalyst with a Ce-O-Mn active system and ZrO2-SO42- protective layer was rationally engineered, which exhibits superior activity for chlorobenzene (CB) and SO2 cotreatment at 228 degrees C, achieving 90% CB mineralization-over 80% higher than that of the CeO2 catalyst. In situ characterization and theoretical calculation results reveal that the SO42- groups not only inhibit the adsorption of SO2 molecules through steric hindrance and electrostatic repulsion but also act as the Br empty set nsted acid sites (BAS) to promote C-Cl cleavage of chlorobenzene (CB) and accelerate the desorption of Cl radicals as inorganic chlorine (HCl and Cl-2). Additionally, the Ce-O-Mn structure accelerates electron transfer between active sites, enhances the strength of Lewis acid sites (LAS), and weakens the lattice oxygen stability to generate oxygen vacancies (O-v). These features collectively result in the excellent chlorine and sulfur resistance of the Ce-Mn@ZrO2-SO42- catalyst. Compared to CeO2 and Ce-Mn@ZrO2, chlorinated and sulfated byproducts respectively decrease by 7.9 and 2.7 times in the presence of 100 ppm SO2. This study provides a feasible and promising strategy for engineering efficacious non-noble metal catalysts toward CVOCs' deep purification with SO2 impurity, showcasing substantial economic and environmental benefits.

The dynamic stall induced by platform surge motion significantly reduces the output power of a floating wind turbine and shortens the machine's operational lifespan. This work examines the impact of a D-SFJ active flow control, featuring two suction slots on the suction side and two injection slots near the trailing edge on the pressure side, on the aerodynamic performance of the NREL 5 MW reference wind turbine during surge motion. Numerical simulations are conducted using the Unsteady Reynolds-Averaged Navier-Stokes (URANS) method with the shear stress transport (SST) k-omega turbulence model and the overset mesh technique is performed. The findings confirm that the surge motion dynamically enlarges the flow separation region over the blade surface, with a maximum increase of 164.29 % in comparison to the wind turbine in a fixed state. The control device implemented in the entire rotor can enhance the aerodynamic performance and improve the flow pattern throughout a single surge cycle. For instance, at an inflow of 7 m/s and a jet strength of 0.01, the D-SFJ device yields a 4.82 % increase in average net output power and the separation area can be reduced by 54.68% compared to the baseline rotor.

Developing efficacious catalysts with superior Cl resistance and polychlorinated byproduct inhibition capability is crucial for realizing the environmentally friendly purification of chlorinated volatile organic compounds (CVOCs). Activating CVOC molecules and desorbing Cl species by modulating the metal-oxygen property is a promising strategy to fulfill these. Herein, a bifunctional CoRu/Al2O3 catalyst with synergistic Co and Ru interactions (Ru-O-Co species) was rationally fabricated, which possesses abundant surface Co2+ and Ru delta+ sites and collaboratively facilitates the activation of lattice oxygen (O2-) and molecular oxygen (O-2 -> O2- -> O-), accelerating 1,2-dichloroethane (1,2-DCE) decomposition via the reaction route of enolic species -> aldehydes -> carboxylate/carbonate. Furthermore, CoRu/Al2O3 stimulates 1,2-DCE oxidation under humid conditions as H2O molecules can be easily activated to active *OH (potential oxidizing agent) over Ru species, accelerating C-Cl dissociation and Cl desorption and promoting the transformation of catecholate-type (C=O) species to easily oxidizable carboxylic acid (COOH) species, remarkably suppressing the formation of hazardous CCl4 and CHCl2CH2Cl. This study provides critical insights into the development of bifunctional catalysts to synergistically activate surface oxygen species and H2O molecules for industrial CVOC stable and efficient elimination.

Based on the single-channel jet control strategy with a suction slot on the upper surface and injection slots near the trailing edge on the lower surface, proposed in this work is a novel flow control technique, known as the dualchannel jet, which amalgamates the beneficial aspects of leading-edge suction and a suction slot positioned downstream of the airfoil's maximum thickness position. To demonstrate the superior aerodynamic characteristics of the dual-channel over the single-channel, comprehensive comparisons of three distinct control strategies are made with two jet momentum coefficients employed on the S809 airfoils. Simulations using Reynoldsaveraged Navier-Stokes with a transitional SST turbulence model are performed, showing that the position of a suction slot in the single-channel significantly impacts its ability to inhibit separation, while the dual-channel jet facilitates a fuller boundary layer velocity profile and a posterior shift in the stagnation point, outperforming the single-channel approach in removing low-momentum fluid and increasing the airfoil virtual camber. In the case with a jet strength of 0.004 and pitching oscillation, compared to the clean airfoil, the dual-channel achieves a remarkable 84.21 % increase in the lift coefficient at 18.1 degrees, and the control efficiency can further be enhanced with the momentum coefficient increased.

BACKGROUND:The ubiquity of sex across eukaryotes, given its high costs, strongly suggests it is evolutionarily advantageous. Asexual lineages can avoid, for example, the risks and energetic costs of recombination, but suffer short-term reductions in adaptive potential and long-term damage to genome integrity. Despite these costs, lichenized fungi have frequently evolved asexual reproduction, likely because it allows the retention of symbiotic algae across generations. The lichenized fungal genus Lepraria is thought to be exclusively asexual, while its sister genus Stereocaulon completes a sexual reproductive cycle. A comparison of sister sexual and asexual clades should shed light on the evolution of asexuality in lichens in general, as well as the apparent long-term maintenance of asexuality in Lepraria, specifically. RESULTS:In this study, we assembled and annotated representative long-read genomes from the putatively asexual Lepraria genus and its sexual sister genus Stereocaulon, and added short-read assemblies from an additional 22 individuals across both genera. Comparative genomic analyses revealed that both genera were heterothallic, with intact mating-type loci of both idiomorphs present across each genus. Additionally, we identified and assessed 29 genes involved in meiosis and mitosis and 45 genes that contribute to formation of fungal sexual reproductive structures (ascomata). All genes were present and appeared functional in nearly all Lepraria, and we failed to identify a general pattern of relaxation of selection on these genes across the Lepraria lineage. Together, these results suggest that Lepraria may be capable of sexual reproduction, including mate recognition, meiosis, and production of ascomata. CONCLUSIONS:Despite apparent maintenance of machinery essential for fungal sex, over 200 years of careful observations by lichenologists have produced no evidence of canonical sexual reproduction in Lepraria. We suggest that Lepraria may have instead evolved a form of parasexual reproduction, perhaps by repurposing MAT and meiosis-specific genes. This may, in turn, allow these lichenized fungi to avoid long-term consequences of asexuality, while maintaining the benefit of an unbroken bond with their algal symbionts.

振动噪声的抑制是近年来开关磁阻电机研究的热门领域.根据麦克斯韦张量法理论分析了径向磁拉力减小的原理,通过在定子齿顶、转子齿两侧同时开矩形槽,增大了定转子间气隙长度的同时又将一部分沿径向方向的磁通密度改变为切向方向,减小了径向磁拉力,达到抑制电磁振动的目的.利用参数化扫描的方法,对开关磁阻电机的开槽参数进行了优化,得出开槽尺寸,并对比分析开槽前后电机的径向磁拉力.运用Ansys Workbench模块分别对定转子齿开槽前后的电机定子进行模态、谐响应以及噪声分析,得到其模态固有频率、模态参与因子、振动响应频率以及声压频谱.分析结果表明:该方法有效减小了开关磁阻电机的径向磁拉力,改善了开关磁阻电机的振动和噪声.

Bearingless switched reluctance motor (BSRM) adopts a doubly salient structure without windings on the rotor. BSRMs have the advantages of high rate of fault tolerance and simple structure, high power, super high speed and strong adaptability. They have broad application prospects in aerospace, flywheel energy storage, new energy and biomedical fields. Firstly, the suspension operation mechanism of a conventional double winding BSRM is described in this paper. The coupling between torque and suspension force is analyzed with a finite element method. On this basis, from the perspective of magnetic circuit optimization of the torque system and suspension system, the magnetic circuit design, decoupling mechanism and performance characteristics of self-decoupled BSRMs with different topological structures are described centering on the self-decoupled topology form of the BSRM. Finally, the study and development of BSRMs in the future are prospected based on the research status.

无轴承开关磁阻电机(BSRM)由于容错性高、损耗小、效率高等优点在工业领域已得到广泛应用,但电机运行时振动会限制其在某些领域的应用.以混合励磁双定子BSRM为研究对象引入一种在定转子齿部开窗的方法,通过改变外定子或转子铁心磁阻大小,可以减小气隙中的磁密大小,达到减小电磁振动的目的.采用电磁有限元法与正交试验法优化窗口的位置和尺寸,验证转子开窗对外定子径向力和转矩的影响,最后通过模态叠加法验证转子开窗对振动响应的影响.结果表明,该方法对混合励磁双定子BSRM电磁振动有较好的抑制效果但对电机转矩有一定影响.

This paper presents an extensive examination of the wake characteristics and hydrodynamic performance of a 1:60 scale horizontal axis tidal stream turbine under yawed inflow conditions. Experimental investigations were conducted in a laboratory flume, while numerical simulations utilized the actuator line method and large-eddy simulation technique. The turbine was subjected to an inflow turbulence intensity of 6% and was tested at five different yaw angles (5°, 10°, 15°, 20°, and 30°). The findings demonstrate a substantial reduction in the power coefficient as the yaw angle increases, with a notable drop of 47.1% recorded at a yaw angle of 30°. Furthermore, numerical simulations of wake characteristics, including mean velocity and turbulence intensity, were examined and compared with measurements, yielding satisfactory agreement. The yawed wake flow exhibited asymmetrical distributions of mean velocity and deviations from the centerline. Additionally, distinct deformations of the yawed wake in the y-z cross sections were observed, indicating a discernible curled kidney shape that intensified with larger yaw angles. Moreover, interactions between the turbine wake and support structures affected the width and turbulence intensity of the near wake, introducing additional unsteadiness that accelerated wake recovery.

Numerical investigations have been carried out regarding the aerodynamic performance of deformable trailing edge flaps (DTEFs) to reduce the unsteady loads on the FFA-W3-241 airfoil under dynamic stall conditions. Simulations were conducted within the framework of OpenFOAM using Reynolds-averaged Navier-Stokes (RANS) approach with the SST k-ω turbulence model and dynamic mesh technique. The control effects of the DTEF size and deflection angle on the stationary airfoil were evaluated through comparative calculations. Then, comprehensive simulations were conducted to gain a deeper insight into the aerodynamic characteristics of a combined simultaneous airfoil-DTEF oscillating motion. Effects of the flap size, oscillation amplitude, frequency, and phase shifts on the airfoil lift and drag hysteresis loops have been analyzed. When the DTEFs oscillate in the same frequency as the airfoil pitch motion and with the phase shift angle of π, the dynamic load can be effectively alleviated. Under this condition, with the appropriate arrangement of flap size and oscillation amplitude, reduction of the lift fluctuations during dynamic motion can be achieved by a maximum of 42.78%, and the corresponding lift-to-drag ratio can also be regulated within a small variation range at a relatively high level.

The 12/14 bearingless switched reluctance motor was designed to restrain the coupling of torque current to suspension system. However, the robustness of the suspension system is reduced due to the time-varying current and displacement stiffness coefficients, thereby hindering its high-reliable application in the on-board flywheel battery for vehicle. A coupling suspension force regulator (CSFR) that consists of a position decoupling suspension force model (PDSFM) and a dynamic coupling observer (DCO) is designed to solve the above-mentioned problem. The time-varying model of the suspension force is established based on the Maxwell stress method and finite element analysis, which is further decomposed into PDSFM and time-varying coupling suspension force component. The PDSFM is used for the feedback model of suspension system to construct a steady suspension system. The DCO is designed based on the PDSFM to capture the time-varying coupling suspension force component as an external disturbance and feed forward compensation to the suspension control system. The time-varying suspension system is effectively transformed into a time-invariant steady suspension system through the effective cooperation of the PDSFM and DCO. The validity of the CSFR is verified through simulations and experiments.

温度精确控制是SMT回流焊炉最重要的控制单元之一.针对回流焊炉温度控制系统的非线性、大迟滞和易受干扰等特点,提出了一种基于模糊免疫自整定的PID算法.通过采用模糊免疫算法自动调节比例系数、积分系数和微分系数,实现温度的快速和稳态控制.最后,利用Simulink仿真验证了所提算法的有效性.结果表明,该控制器能够明显改善温度控制系统的动态跟随性能,实现参数在线自整定,即使在10％的随机干扰下,依然能够快速恢复到稳定状态.

In order to improve the frequency stability of the AC-DC hybrid system under high penetration of new energy, the suitability of each characteristic of flywheel energy storage to participate in primary frequency regulation of the grid is explored. In this paper, based on the basic principle of vector control of SVPWM modulation technology, the feedforward current inner loop control method is used to realize the decoupling of dq-axis current, and the flywheel energy storage motor charging composite control strategy based on id=0 and weak magnetic control is adopted for two different modes of constant torque and constant power, respectively. The simulation model of flywheel energy storage is designed and built. By adopting the hybrid control strategy for charging and discharging flywheel energy storage, it is verified that the speed and torque of flywheel motor fluctuate less and have good anti-disturbance characteristics when the disturbance is suddenly added, and it can improve the frequency stability of the grid when applied to the grid frequency regulation.

The strong coupling effect between the torque system and the suspension system of the single-winding bearingless switched reluctance motor (SWBSRM) would result in continuous interference to the system and bring difficulties to the design of the control system. Moreover, strong external disturbances will further reduce the stability of the control system. To improve the anti-disturbance ability and enhance the robustness of the control system of SWBSRM, a design method of the entire control system based on the second-order sliding mode (SOSM) controllers is proposed. The strongly coupled SWBSRM torque system and suspension system are linearised and decomposed through the feedback linearisation method to benefit the design of SOSM controllers. Then, combined with a super-spiral algorithm, the super-spiral sliding mode controllers in the outer loop for torque and suspension system are designed separately. The design of controllers considers the interference caused by the coupling effect and the influence of external disturbance. The range of gain, which can ensure the finite time convergence of the control system is determined through proof of stability. Simulation and experiment results show that the second-order sliding mode controllers have faster response speed and control precision when suppressing coupled interference and strong external disturbance.

A novel dual 6/3 Transverse Flux Bearingless Switched Reluctance Motor is proposed to solve the coupling problem between torque and suspension of conventional Switched Reluctance Motor. The working principle is introduced in detail, the motor is modelled by ANSYS, and the accurate mathematical model of the suspension force is deduced and verified. The electromagnetic characteristics of the motor are simulated, and the torque characteristics, suspension characteristics and the coupling characteristics between them are verified. The simulation results show that the torque and suspension force can be stabilised by using the zoning control of torque and suspension force, and the decoupling between torque and suspension force is excellent.

提出了一种混合励磁双定子磁悬浮开关磁阻电机(BSRM)的等效磁网络模型,此模型可以分析电机悬浮和转矩绕组的磁链、电感及悬浮力和转矩等静态特性.等效磁网络法(EMN)不仅能保证一定的精度,而且比有限元法(FEM)节省时间.基于一种24/16/8极混合励磁双定子BSRM建立EMN模型,推算出电机定转子齿部、轭部以及气隙磁导的计算公式.建立矩阵方程,求解出各部分的磁通密度,进而求出悬浮和转矩绕组的磁链、电感以及悬浮力和转矩特性,和FEM求解的结果进行对比.可以发现EMN模型求解出的电磁特性和FEM分析的结果吻合效果很好,进一步证明了所建模型的有效性.