A rotating magnetic field (RMF) was employed to manipulate the crystallization of perovskite films during blade coating.

Perovskite-based solar cells have been developed intensively in recent years because of their attractive applications in next-generation photovoltaics with low cost and high efficiency. However, the fabrication processes need to be further improved to meet the requirements in actual industrial production with reliable process and scalable fabrication. Here, coordinated thermal/solvent engineering-enhanced rapid crystallization strategy is reported to realize the fast and robust preparation of perovskite films. The modified solution-based coating method enables the precursor solutions to rapidly form highly crystalline perovskite films with large crystal domains through effectively controlled growth dynamics, including the nucleation and lateral growth processes. Benefitted from specific crystallization mechanisms, high-quality perovskite films with efficient photovoltaic performance in corresponding devices were readily produced either using the blade-coating or even the painting method: an average power conversion efficiency (PCE) of 16.32% was obtained when using the blade-coating method and up to 16.01% average PCE was realized by the direct painting process. Most importantly, this one-step painting method is demonstrated to be fairly reliable with high repeatability, showing a promising future for the scalable and rapid production of perovskite film with controllable film uniformity and thickness.

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The ultrasonic technique is one of the most promising methods to nondestructively evaluate the interface. When the adhesive bonding is not perfect, part of ultrasonic energy is reflected from the interface. The reflection signal can be used to estimate the adhesive strength. In this investigation, a spectral analysis is employed using Fast Fourier Transform (FFT) to evaluate the reflection signal in frequency domain. The frequency spectrum of the reflection signal is then deconvolved with a reference signal taken from the bottom of the test block to determine the interfacial stiffness which can provide useful information on the nature of the adhesive interface. In this work, two aluminum blocks are adhesively bonded with the epoxy. The adhesive bond strength measured by a tensile testing is correlated with the interfacial stiffness. Experimental results show that the adhesive bond strength is linearly increasing with the increase in interfacial stiffness. It demonstrates that the adhesive bond strength can be characterized using the single parameter of interfacial stiffness. The present study reveals the feasibility of assessing the adhesive bond strength with the ultrasonic technique.

Effect of curing temperature on properties of ovalbumin has been investigated. Functional basis, crosslinking degree, tensile strength, and hardness increases with rising curing temperature. The increase of visible transmittance and the decrease of absorption accompany with increasing wavelength. The absorptive peak shows at 440-450 nm and the wavelength of the absorptive peak increases with the rising curing temperature. The relationship of joint strength with solvent welded joints of ovalbumin to their microstructure is also investigated. Ovalbumin can promote joint strength after the treatment of distilled water and curing. Comparing joint strength with fracture morphology, the smoother fracture surface morphology is related to the maximum tensile and shear joint strength, respectively. The joint strength is increasing with curing temperature and compressive stress, and the joint strength of treatment with 150 C curing temperature and 0.12 kgf/mm 2 compressive stresses are larger than its original tensile fracture strength of cured ovalbumin at same curing temperature.

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The proton battery possesses water electrolysis, proton storage and discharging functions simultaneously, and it can be manufactured without expensive metals. Use the principle of proton exchange membrane water electrolysis for charging, store it in the activated carbon on the hydrogen side and use the principle of proton exchange membrane fuel cell for discharge when needed. According to the latest literature, it is difficult to obtain the exact important physical parameters inside the proton battery (e.g., voltage, current, temperature, humidity and flow), and the important physical parameters are correlated with each other, which have critical influence on the performance, lifetime and health status of the proton battery. At present, the condition of the proton battery is judged indirectly only by external measurement, the actual situation inside the proton battery cannot be obtained accurately and instantly. Therefore, this study uses micro-electro-mechanical systems (MEMS) technology to develop a flexible 5-in-1 microsensor, which is embedded in the proton battery to obtain five important physical parameters instantly, so that the condition inside the proton battery can be mastered more precisely, so as to prolong the battery life and enhance the proton battery performance.