Accelerated Discovery of Halide Perovskite Materials via Computational Methods: A Review.

Halide perovskites have gained considerable attention in materials science due to their exceptional optoelectronic properties, including high absorption coefficients, excellent charge-carrier mobilities, and tunable band gaps, which make them highly promising for applications in photovoltaics, light-emitting diodes, synapses, and other optoelectronic devices. However, challenges such as long-term stability and lead toxicity hinder large-scale commercialization. Computational methods have become essential in this field, providing insights into material properties, enabling the efficient screening of large chemical spaces, and accelerating discovery processes through high-throughput screening and machine learning techniques. This review further discusses the role of computational tools in the accelerated discovery of high-performance halide perovskite materials, like the double perovskites A2BX6 and A2BB'X6, zero-dimensional perovskite A3B2X9, and novel halide perovskite ABX6. This review provides significant insights into how computational methods have accelerated the discovery of high-performance halide perovskite. Challenges and future perspectives are also presented to stimulate further research progress.

Controlling Welding Residual Stress and Distortion of High-Strength Aluminum Alloy Thin Plates by a Trailing Hybrid High-Speed Gas Fluid Field.

This paper presents an investigation of the welding residual stress and distortion of LY12 high-strength aluminum alloy (6061) by improving the local welding thermal and mechanical fields. A trailing hybrid high-speed gas fluid method was proposed and applied to decrease the welding residual stress and distortion of 6061 aluminum alloy efficiently. Firstly, the temperature and stress fields were calculated using the finite element simulation method, considering a trailing hybrid high-speed gas fluid field. The distance between the aerodynamic load and the heat source action was a key factor determined by the simulation method. In addition, the reasonable effective range of gas pressure was obtained. Subsequently, welding and distortion tests were conducted on the self-developed device under conventional welding and high-speed gas fluid field conditions. The results showed that an aerodynamic load under 30 MPa of gas pressure was available near the area at a distance of 20-28 mm from the heat source for thin plate welding distortion. The peak longitudinal residual tensile stresses in the weld's mid-length section decreased by 77.73%, the peak residual compressive stresses decreased by 69.23% compared with conventional welding, and the deflection distortion disappeared almost entirely. The maximum deflection of the distortion was only 1.79 mm, which was 83.76% lower than the 11.02 mm of the conventional welding distortion. This validates that the method can simultaneously and greatly eliminate the welding residual stress and distortion.

A robust self-alignment method for ship's strapdown INS under mooring conditions.

Strapdown inertial navigation systems (INS) need an alignment process to determine the initial attitude matrix between the body frame and the navigation frame. The conventional alignment process is to compute the initial attitude matrix using the gravity and Earth rotational rate measurements. However, under mooring conditions, the inertial measurement unit (IMU) employed in a ship's strapdown INS often suffers from both the intrinsic sensor noise components and the external disturbance components caused by the motions of the sea waves and wind waves, so a rapid and precise alignment of a ship's strapdown INS without any auxiliary information is hard to achieve. A robust solution is given in this paper to solve this problem. The inertial frame based alignment method is utilized to adapt the mooring condition, most of the periodical low-frequency external disturbance components could be removed by the mathematical integration and averaging characteristic of this method. A novel prefilter named hidden Markov model based Kalman filter (HMM-KF) is proposed to remove the relatively high-frequency error components. Different from the digital filters, the HMM-KF barely cause time-delay problem. The turntable, mooring and sea experiments favorably validate the rapidness and accuracy of the proposed self-alignment method and the good de-noising performance of HMM-KF.

[Comparative observation on curative effects of stenosing tenovaginitis of flexor digitorum treated with acupuncture knife therapy and blocking therapy].

OBJECTIVE: To compare the curative effects on stenosing tenovaginitis of flexor digitorum treated with acupuncture knife therapy and blocking therapy so as to explore the better method. METHODS: Three hundred and four cases were randomly divided into acupuncture knife therapy group (164 cases) and blocking therapy group (140 cases). In acupuncture knife therapy group, hooking and cutting were applied on the pressure points and scleromas with Ren's hooked acupuncture knife; routine blocking therapy was applied in blocking therapy group. The curative effects of both groups after 1-2 treatments and the recurrence after treatment in following 6 months were observed. RESULTS: The curative rate was 98.2% (161/164)in acupuncture knife therapy group, superior to that of 65.7% (92/140) in blocking therapy group; the recurrence rate was 1.9% (3/161) in acupuncture knife therapy group, inferior to that of 37.0% (34/92) in blocking therapy group. The differences are significant between groups (both P < 0.01). CONCLUSION: The curative effect of stenosing tenovaginitis of flexor digitorum treated with acupuncture knife therapy is superior to that of blocking therapy, with low recurrence rate.