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The high resistance connection (HRC) is a typical type of machine winding faults, which is caused by material fatigue and excessive heat in the machine windings. This fault can lead to a temperature rise or even catch a fire if left untreated. HRC fault diagnosis of permanent magnet synchronous motors are of great interest as they are widely utilized in modern industry. At present, HRC faults are mainly diagnosed by observing voltage and current signals. These methods are effective but sometimes invasive if they are not installed in the motor. This article proposes a noninvasive method, which utilizes giant magnetoresistance (GMR) sensors to collect stray magnetic field signals. The location of GMR sensors is determined by finite element Maxwell simulation, and three GMR sensors are installed in the test motor to monitor the stray magnetic field of the motor. Test data are processed by deep learning to locate and quantitatively analyze HRC faults in the motor. Experimental results show that the proposed method is effective in terms of the accuracy and fault identification. This method has potential applications for in situ electric motors.

Magnetic pulse welding (MPW) for dissimilar sheet metals holds significant industrial potential as an environmentally friendly and efficient method. The process and results of MPW are highly dependent on the discharge parameters of MPW equipment. However, the development of excellent performance equipment is challenging and costly, limiting the widespread industrial application of MPW. A novel coil with the capability of amplifying current is proposed in this study, thereby mitigating the stringent requirements on MPW equipment. Firstly, the theoretical model was established to assess the effect of coil structure parameters on RLC (resistance, inductance, and capacitance) within the MPW discharge system and the magnetic pressure exerted on the sheet metal. Subsequently, numerical simulations were employed to investigate the variation trends of current density, Lorentz force, and collision parameters of the flyer sheet basing on different coil structures during the MPW process. Given that coil with 4 turns, diameter of 200 mm and pitch of 30 mm achieves a 3.1 times current amplification and a collision speed of 383.7 m/s of the flyer sheet at 9.8 kJ, while maintaining certain structural stability, the experiments were conducted. Experimental results confirmed that the small error in numerical simulation results. The metallurgical welding features, including the waveform interface, amorphous layer, and element diffusion, were observed at the 1060-DP450 weld interface achieved at 9.8 kJ. Nanoindentation results indicated that work hardening caused a higher hardness (max: 1.808 GPa) near the interface. Mechanical testing of joints welded at different energy levels (6.05–9.8 kJ) revealed that when the discharge energy exceeded 8.45 kJ, the fracture location of the joint occurs in the 1060 rather than the welding area, which is lower than the energy requirement for welding sheets of similar strength levels using traditional coils. Therefore, the novel coil structure proposed in this study reduces the difficulty of the MPW process while ensuring excellent joint performance, which is beneficial for the further industrial application of MPW technology.

A pair of tenellone diastereoisomers with a rare 2,3-dihydro-1H-indene core, showing moderate cytotoxic activity against four human tumor cell lines, were isolated from marine-derived fungus Phomopsis lithocarpusFS508.

Live fish transport is an important aspect of aquaculture, especially at high densities, which might cause considerable stress and compromise product quality. This study investigated the effects of transport density and time on stress responses, innate immunity, and immune gene expression in juvenile yellow catfish. The fish were designated to five density groups: D11, D12, D13, D14, and D15 (500, 333, 250, 200, and 167kg/m3). After 36h of transport, only the D15 group had a 100% survival rate, followed by D14 with 83% survival, and 0% in the remaining three density groups. The damage to gill filaments and the liver worsened with increasing environmental stress severity. The results showed that with the prolonged transport time, plasma cortisol (COR), and catalase (CAT), malonaldehyde (MDA) and lysozyme (LZM) levels in the livers first increased and later gradually decreased after 16h of transport, while the activity of superoxide dismutase (SOD) continued to rise. The activities of CAT and MDA content increased as the density increased. The expression of heat shock protein (HSP) 70 and 90, tumor necrosis factor α (TNF-α), and interleukin-1β (IL-1β) in juvenile livers in D11 group was significantly higher than the control group (p< 0.05), confirming that density imposed stress on fish during transport. In conclusion, we demonstrated that increased density and time during live transport induced significant physiological stress responses in juvenile P. fulvidraco. This study provides insights into the transport of yellow catfish to improve transport measures and reduce economic losses to the aquaculture industry.

Hawanoids A‒E (1‒5), five highly cyclized diterpenoids were isolated from the deep-sea-derived fungus Paraconiothyrium hawaiienseFS482. Compounds 1and 2possessed an unprecedented tetracyclo[6.6.2.02,7.011,15]cetane carbon skeleton while 3and 4possessed an unusual 11,14-macrocyclic ether moiety in phomactin family. Their structures including the stereo-chemistry were determined through spectroscopic analysis, X-ray diffractions and computational calculations. The plausible biosynthetic pathway was proposed based on the predicted biosynthetic gene cluster. All of the isolated compounds exhibited inhibitory activities against PAF-induced platelet aggregation. The molecular docking study was carried out understand the interaction between the PAF receptor and hawanoids with different skeletons.

Triboelectric nanogenerator (TENG) has recently emerged as one of the most promising technologies for capturing low-frequency ocean energy. However, TENG has some disadvantages, such as low volumetric energy density, poor versatility, and poor anti-storm ability, limiting its commercialization. In this study, an O-ring-like TENG (O-TENG) for blue energy harvesting is introduced. This generator can be prepared by flexible splicing of fan-ring-shaped TENG blocks with different angles. The modular design of the O-TENG not only realizes omnidirectional wave energy harvesting but also regulates its response frequency spectrum based on the surroundings, thereby enhancing the energy capture efficiency of the TENG array. The effect of the configuration parameters of the oscillation frequency and swing amplitude was systematically investigated to optimize the output performance of the O-TENG, and a maximum transfer charge of 29.90 μC was obtained. Furthermore, the O-TENG exhibited almost the same charging efficiency even when placed upside-down, demonstrating its anti-storm ability against strong winds and wave interferences. Experimentally, O-TENG can efficiently capture wave energy on the wave pool and drive commercial RF modules to realize wireless signal transmission successfully. This work demonstrates that O-TENGs can capture wave energy and are a potential energy source for ocean monitoring systems, promoting the construction of the IoTs.

The reaction of selenous acid with template grown indium nanowires generates a poorly structured indium (I) selenide tubular product. The electron diffraction pattern from the sample exhibited no crystallinity. The Raman spectrum of the deposit is a broad band centred on 160 cm-1 that is not consistent with the known Raman spectra for indium selenides or elemental selenium. Annealing of the deposit yielded a polycrystalline tube structure where the tubes are similar in size to the as-deposited material. SAED of the grains that form these tubes revealed them to be individual indium (I) selenide crystals.