Low‐dimensional metal‐halide perovskites have exhibited significantly superior nonlinear optical properties compared to traditional semiconductor counterparts, thanks to their peculiar physical and electronic structures. Their exceptional nonlinear optical characteristics make them excellent candidates for revolutionizing widespread applications. However, the research of nonlinear photonics based on low‐dimensional metal‐halide perovskites is in its infancy. There is a lack of comprehensive and in‐depth summary of this research realm. Here, the state‐of‐the‐art research progress related to third‐and higher‐order nonlinear optical properties of low‐dimensional metal‐halide perovskites with diverse crystal structures from 3D down to 0D, together with their practical applications, is summarized comprehensively. Critical discussions are offered on the fundamental mechanisms beneath their exceptional nonlinear optical performance from the physics viewpoint, attempting to disclose the role of intrinsic attributes (e.g., composition, bandgap, size, shape, and structure) and external modulation strategies (e.g., developing core–shell structures, transition metal ion doping, and hybridization with dielectric microspheres) in tuning the response. Additionally, their potential applications in nonlinear photonics, nonlinear optoelectronics, and biophotonics are systematically and thoroughly summed up and categorized. Lastly, insights into the current technical challenges and future research opportunities of nonlinear photonics based on low‐dimensional metal‐halide perovskites are provided.

Background: The “Double Reduction” policy changed the education market landscape overnight in China. This study aimed to develop a strategic development model for the sports education market within the context of the “Double Reduction” policy. Methods: This study employed a hybrid model of SWOT (strengths, weaknesses, opportunities, and threats) and AHP (analytic hierarchy process). First, SWOT factors were identified by a literature review and survey. In 2022, 30 managers and 251 parents from Changsha and Tianjin were surveyed regarding the sports education market. Second, five decision-makers from the Changsha sports education market performed a pairwise comparison of the AHP analysis, which was used to determine weights, consistency ratios, and intensities of SWOT factors. Third, the strategic vector method was used to develop the strategic development model. Results: Sixteen SWOT factors were determined. The strategic quadrilateral’s center of gravity is positioned in quadrant II (−0.0595, 0.0246). The strategic azimuth is 157.5°, and the strategic coefficient is 0.49. The strategic vector is located at the striving zone of the adjustment type. Conclusions: A conservative business strategy should be implemented in the current sports education market. Four novel strategies were proposed to support the high-quality development of the Chinese sports education market.

Green building materials have brought fundamental changes to the traditional construction methods, enabling better environmental protection and energy-saving performance of the buildings. However, due to the various material types and the large property differences, until now there isn’t a uniform evaluation index system (EIS) for green building materials, the existing studies on the green-level evaluation of green building materials during production and use are insufficient, and the research on energy-saving design is just getting started. For this reason, this paper attempted to launch a research on the multi-objective energy-saving optimization design of buildings based on the application of green building materials. First, the quantification method for the environmental impact factors of green building materials was elaborated, and the intervals and standards of the quantification evaluation were given; then, a green building material optimization selection model was constructed, and a multi-objective energy-saving optimization algorithm was proposed; at last, experimental results gave the green levels of a few candidate green building materials and the scores of the environmental impact factors, which had verified the effectiveness of the proposed algorithm.

Reported herein is an effective strategy for oxidative cross-coupling of indoles with various aldehydes. The strategy is based on a two-step transformation via a well-known Mannich-type reaction and a C–N bond cleavage for carbonyl introduction. The key stepthe C–N bond cleavage of the Mannich productwas enabled by electrochemistry. This strategy (with over 40 examples) ensures excellent functional-group tolerance as well as late-stage functionalization of pharmaceutical molecules.

Metro accessibility is a concept used to describe the dynamic accessibility index of metro transportation systems. Most studies on accessibility apply a static approach, which overlooks the index fluctuations throughout the day. While it is possible to represent the accessibility using a single index, the ability to capture the dynamic nature of the index is important in understanding the quality of a transportation service and identify actionable aspects for improvement. For example, when the metro system is overcrowded and passengers fail to board the next arriving train, they instead wait for the subsequent train. As a result, the accessibility of the system is deemed to be lower than when its condition is uncrowded. This paper analyzes and integrates two aspects of metro accessibility: the performance of metro networks; and the dynamics of train schedules. An evaluation model in the form of a gravity model is proposed to measure the accessibility between each pair of stations with the dynamic travel time. This allows us to obtain profiles that highlight the daily variations in accessibility in the metro network and to identify the influence of congestion among stations. The effectiveness of the proposed evaluation model is validated using the metro network of Shenzhen in China. Results show that the proposed methodology provides useful information for passengers and travel guides as well as technical reference for the metro operation guidelines that are used to compile train schedules.