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The study on structure‐property relationship has been a significant focus in the field of organic molecular luminescence. In the present work, three chiral binaphthyl‐based triphenylethylene (HTPE) derivatives were prepared through condensation reactions. Despite their similar structures, these compounds exhibited distinct luminescent properties. Diphenylmethane‐derived HTPE displayed dual‐state emissions, characterized by dual‐wavelength emissions which were insensitive to the polarity of solvents. The dual emissions in solution state could be attributed to the different locally excited (LE) excitons. However, upon aggregation, two stable conformers were generated, probably leading to different emission peaks. In contrast, dibenzocycloheptadiene‐derived HTPE aggregates showed only a single emission peak. Surprisingly, fluorene‐derived HTPE exhibited obvious luminescence in neither solution nor aggregate states due to inherent π‐π interactions. These conclusions were substantiated by X‐ray analysis, spectroscopic analysis, and theory calculations. Application studies demonstrated that fluorescence on/off switches could be achieved through exposure to acetone. More importantly, trace amounts of acetone could be detected using luminescent materials in both organic and aqueous phases with a detection limit of 0.08 %. Thus, this work not only presents a strategy for designing chiral triphenylethylene fluorophores but also provides valuable information for dual wavelength emissions resulting from two stable conformations. [ABSTRACT FROM AUTHOR]

A simple method for the preparation of 2-aryl-3-(2-aminoaryl)quinoxalines from 2-alkynylnitrobenzenes and 1,2-diaminoarenes was described. The reactions could proceed under mild conditions. The 1-nitro-2-(phenylethynyl)benzenes, simple starting materials, could generate the key intermediate 3H-indole-3-ones in situ in the presence of PPh3. After a cyclization with 1,2-diaminobenzenes, the 3H-indole-3-ones were then transformed into biologically valuable quinoxalines. [ABSTRACT FROM AUTHOR]

With the development trend of aging and low fertility in China, disability and dementia increase year by year in the elderly population. The demand of long-term life care service for the elderly with disability and dementia brings great challenges to the service supply and funds of the traditional endowment insurance model. However, with the application of blockchain technology, the Time Bank’s mutual-support old-aged care mode can better solve the above problems. First, the author uses SWOT analysis to comprehensively analyze the advantages, difficulties, opportunities and challenges of the Time Bank’s Mutual-support for the Aged mode in China, then the blockchain technology is applied to this mode, finally the corresponding optimization scheme and suggestions are put forward.

By using questionnaire survey and statistical analysis method, this paper studies the influencing factors of medical students' behavior of seeking medical care and the utilization of medical services. It is found that there are three main choices of medical students' behavior of seeking medical care after illness, which are school hospital, community health service center and self-treatment, accounting for 36.5%, 24.2% and 15.9% respectively. And the grade, place of origin, medical security system and self-rated health status had significant effects on medical students' medical behavior (P

Mountainous cities face various land use challenges, including complex topography, low land use efficiency, and the insufficient control of land use in small-scale areas at the urban fringe. Considering population changes, environmental conservation, and urban planning, this study first established three scenarios: economic priority (Econ. Prior.), ecological priority (Ecol. Prior.), and balanced development (BD), and then used the Multi-Objective Planning (MOP) model to calculate the optimal land use structure. Finally, it carried out land use spatial layout optimization based on the Patch-generating Land Use Simulation (PLUS) model in 2035, Caijia Cluster, Chongqing, China. This approach, known as MOP-PLUS modeling, aimed to optimize land use. Meanwhile, the applicability of the PLUS model in simulating land use changes was discussed in small-scale mountainous areas. The results show the following: (1) The "quantity + space" approach in the MOP-PLUS model demonstrated the feasibility of the PLUS model in simulating land use change in small-scale mountainous areas. The overall accuracy (OA) of land use change simulation reached 81.60%, with a Kappa value of 0.73 and a Figure of Merit (FoM) coefficient of 0.263. (2) Land use optimization: Under the Econ. Prior. scenario, economic benefits peaked at 4.06 × 1010 CNY. Urban expansion was the largest, leading to increased patch fragmentation. The Ecol. Prior. scenario yielded the highest ecological benefits, reaching 7.46 × 107 CNY. The urban development pattern exhibited inward contraction, accompanied by urban retrogression. In the BD scenario, economic benefits totaled 3.89 × 1010 CNY, and ecological benefits amounted to 7.16 × 107 CNY. Construction land tended to concentrate spatially, leading to relatively optimal land use efficiency. Therefore, based on a comprehensive consideration of the regional land use constraint policies and spatial layout, we believe that a balance point for land use demands can be found in the BD scenario. It can ensure economic growth without compromising the ecological environment. [ABSTRACT FROM AUTHOR]

A variety of 5‐indo‐1‐yl pyran‐2‐ones with an N−C axis were prepared via a carbene‐catalyzed oxidative [3+3] annulation of indole‐1‐pyruvate esters and enals. Asymmetric construction of pyran‐2‐one ring from enals ensures the realization of this strategy. The resulting compounds were converted into axially chiral N‐arylindoles with an N−C axis via a cycloaddtion aromatization. [ABSTRACT FROM AUTHOR]