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Two-dimensional (2D) MoS2 nanomaterials have been extensively studied due to their special structure and high theoretical capacity, but it is still a huge challenge to improve its cycle stability and achieve superior fast charge and discharge performance. Herein, a facile one-step hydrothermal method is proposed to synthetize an ordered and self-assembled MoS2 nanoflower (MoS2/C NF) with expanded interlayer spacing via embedding a carbon layer into the interlayer. The carbon layer in the MoS2 interlayer can speed the transfer of electrons, while the nanoflower structure promotes the ions transport and improves the structural stability during the charging/discharging process. Therefore, MoS2/C NF electrode exhibits exceptional rate performance (318.2 and 302.3 mAh·g−1 at 5.0 and 10.0 A·g−1, respectively) and extraordinary cycle durability (98.8% retention after 300 cycles at a current density of 1.0 A·g−1). This work provides a simple and feasible method for constructing high-performance anode composites for sodium ion batteries with excellent cycle durability and fast charge/discharge ability.

The main tasks of the space station are to execute the manned space flight activities, scientific experiments, observation of astronomical phenomena, and maintenance of satellites for a long time. For a lot of scientific applications, it is necessary to increase the pressure in the cabin, which leads to the difference between the internal and external pressure. Then, the strain can be generated. The real-time and accurate monitoring of the strain on the cabin is one of the important factors to ensure the safety of astronauts. In China, it is the first time to measure the strain of the cabin by means of fiber Bragg grating (FBG) sensors. The optical fiber sensor has a measurement error of less than 4.52 μe in the circumferential direction as compared with a resistance strain gauge acted as a reference. But the axial measurement error is very big, and the maximum is 28.93 μe. As a comparison, the strain of bare fiber in the axial direction is measured, and it is found that the error is terribly small. According to theoretical calculations, the transverse effect coefficient is 0.0271, and the experimental result is 0.0287. These two values are approximately consistent. By compensating the transverse effect of the FBG sensor, the measurement error is decreased by about one order of magnitude. It will be conducive to accomplish the health monitoring and condition assessment of space station.

The phase velocity matching Lamb waves are considered as an effective solution to excitation in the detection of nonlinear ultrasound early fatigue damage. In general, it is difficult to meet the phase velocity matching in real-world measurement. In this paper an approach to approximate phase velocity matching early fatigue damage detection is proposed. With the third harmonic approximate phase velocity matching modes treated as excitation frequencies by the Lamb wave dispersion curve, an analysis is conducted with regard to the time-frequency diagrams of the response signals at different frequencies. The change in the third harmonic amplitude with crack growth is analyzed by Fast Fourier Transform (FFT), which leads to the results suggesting that the third harmonic amplitude declines with crack growth. Moreover, a comparison is performed in the normalized relative third-order nonlinear parameters(NRTNP) of phase velocity matching and approximate phase velocity matching, with the relative deviation falling within 0.12.

Heterostructures have gained intensive attentions in various energy storage fields due to their diverse physicochemical properties and functions, originating from the synergistic effects and interfacial interaction between the different components. However, it is still a great challenge to employ simple methods to design an advanced heterostructure for superior sodium storage performances. Herein, a facile in situ localized phase transformation strategy has been developed to transfer MoO3 nanoparticles anchored on rGO nanosheets into MoO2@MoS2 heterostructures (MoO2@MoS2/rGO). Benefiting from faster ion transport at the heterogeneous interface, higher conductivity as well as more active sites for Na storage than that of single component, MoO2@MoS2/rGO electrode exhibits distinguished reversible capacity (604.1 mAh g−1 at 0.1 A g−1) and remarkable rate performance (420.8 mAh g−1 at 5.0 A g−1) when evaluated as an anode for SIBs. This work provides a simple and feasible method for constructing stable heterostructures for high-performance energy storage materials.

Resistive switching (RS) effect has attracted enormous attention due to its potential for application of resistive random access memory with fast speed, good scalability and high endurance. NiO is a model system of RS effect, in which the formation/rupture of nickel filaments is directly related to the RS effect. In fact, it is still controversial that the RS effect in NiO films should be attributed to whether a single filament or multi-filaments. In this work, we demonstrate that multi-filaments are involved in the RS process by means of conventional I-V measurements, conductive atomic force microscopy and transmission electron microscopy. Furthermore, we observed the interesting tunneling magnetoresistance in this system for the first time, which not only reveals the mechanism of multi-filaments, but also provides a new way for multifunctional devices.