Counts of the book borrowing records based on the distribution of students’ information (in segments of subject specialties and by genders).

Counts of the book borrowing records based on the distribution of students’ information (in segments of subject specialties and by genders).</p

The BSF probability distribution on information entropy.

The BSF probability distribution on information entropy.</p

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Library data contains many students’ reading records that reflect their general knowledge acquisition. The purpose of this study is to deeply mine the library book-borrowing data, with concerns on different book catalogues and properties to predict the students’ extracurricular interests. An intelligent computing framework is proposed by the fusion of a neural network architecture and a partial differential equations (PDE) function module. In model designs, the architecture is constructed as an adaptive learning backpropagation neural network (BPNN), with automatic tuning of its hyperparameters. The PDE module is embedded into the network structure to enhance the loss functions of each neural perceptron. For model evaluation, a novel comprehensive index is designed using the calculus of information entropy. Empirical experiments are conducted on a diverse and multimodal time-series dataset of library book borrowing records to demonstrate the effectiveness of the proposed methodology. Results validate that the proposed framework is capable of revealing the students’ extracurricular reading interests by processing related book borrowing records, and expected to be applied to “big data” analysis for a wide range of various libraries.</div

The predictive MSE and R² for the available optimal 8 PDE-improved BPNN models.

The predictive MSE and R2 for the available optimal 8 PDE-improved BPNN models.</p

Counts of the domestic and foreign book borrowing records classified by CLC catalogue.

Counts of the domestic and foreign book borrowing records classified by CLC catalogue.</p

The designed BPNN architecture in fusion with the PDE module.

The designed BPNN architecture in fusion with the PDE module.</p

The histogram for the distribution of time length of book borrowing.

The histogram for the distribution of time length of book borrowing.</p

The prediction results of different structural BPNN models for quantitative analysis of the library book borrowing record data.

The prediction results of different structural BPNN models for quantitative analysis of the library book borrowing record data.</p

The confronting challenges and our planned solutions.

The confronting challenges and our planned solutions.</p

Mn²⁺ and Sb³⁺ Codoped Cs₂ZnCl₄ Metal Halide with Excitation-Wavelength-Dependent Emission for Fluorescence Anticounterfeiting

In recent years, there has been a growing demand for luminescence anticounterfeiting materials that possess the properties of environmentally friendly, single-component, and multimode fluorescence. Among the materials explored, the low dimensional metal halides have gained wide attention because of unique characteristics including low toxicity, simple synthesis, good stability, and so on. Here, we synthesized Mn2+ and Sb3+ codoped Cs2ZnCl4 single crystals by a facile hydrothermal method. Under 365 nm excitation, the codoped compound exhibits dual-band emissions at 530 and 730 nm. However, under 316 nm excitation, the compound only shows one emission band from 500 to 850 nm peaking at 730 nm, while under 460 nm excitation, the emission from 500 to 650 nm with an emission peak at 530 nm can be observed. Based on the study of the photoluminescence mechanism, the green and red emissions originate from the Mn2+ located in the tetrahedron and self-trapped exciton emission of [SbCl4]− clusters, respectively. Due to the zero-dimensional structure of the Cs2ZnCl4 host, there is minimal energy transfer between these dopants. Consequently, the luminous ratios of the two emissions can be independently regulated. Except by tuning the dopant concentrations, the Cs2ZnCl4:Mn2+, Sb3+ demonstrates excitation-wavelength-dependent properties, which could emit more than two colors with the change of excitation wavelength. As a result, multimode anticounterfeiting based on Cs2ZnCl4:Mn2+, Sb3+ crystals has been designed, which aligns with the requirements of environmentally friendly, single-component, and multimode fluorescence properties