摘要 : In this paper, we show that the reduced spherical regular polygons of any fixed thickness have the minimal diameters and minimal circumradii among all reduced spherical polygons of the same thickness. © 2023, The Managing Editors.

摘要 : A derivative of fluorescein, fluorescein O, O-diacrylate (FODA), was utilized in a triplet–triplet annihilation upconversion (TTA-UC) system to develop a composite ratiometric chemosensor capable of detecting cysteine (Cys). FODA acted as both the probe for Cys and the energy acceptor for upconversion (UC) emission, thereby making UC a responsive signal to Cys. In addition, the phosphorescence signal of the sensitizer in the TTA-UC system remained constant and did not respond to Cys, making it an ideal internal reference signal for constructing a ratiometric sensor. Through this simple strategy, traditional fluorescent probes can be combined with TTA-UC system to establish a ratiometric sensing platform, which can be applied in more scenarios due to the longer wavelength excitation.

摘要 : The types of disgust guide individuals to seek healthier mates and avoid risky sexual behaviors. However, research integrating the relationships between the types of disgust and mating is still lacking. Through the three studies either measuring types of disgust together (study 1, N1 = 335, China) or separately (study 2, N2 = 233, China; study 3, N3 = 267, the Netherlands), we found that after controlling for shared variances, higher pathogen disgust was associated with a stronger preference for physical attractiveness. Higher sexual disgust was associated with lower short-term but higher long-term mating orientation. Higher moral disgust was associated with higher long-term mating orientation and a stronger preference for mate commitment. In study 3, we also measured perceived norms surrounding short-term and long-term mating. Results showed that though both types of mating behavior were considered approved by their social groups, participants perceived long-term mating as more so. Moreover, sexual disgust was negatively associated with perceived approval of short-term mating. Finally, we performed mega-analyses collapsing the data from the three studies. Current research provides evidence that different types of disgust play a role in specific aspects of mating psychology.

摘要 : In this paper, we first initialize the S-product of tensors to unify the outer product, contractive product, and the inner product of tensors. Then, we introduce the separable symmetry tensors and separable anti-symmetry tensors, which are defined, respectively, as the sum and the algebraic sum of rank-one tensors generated by the tensor product of some vectors. We offer a class of tensors to achieve the upper bound for \(\texttt {rank}({\mathcal {A}}) \leqslant 6\) for all tensors of size \(3\times 3\times 3\). We also show that each \(3\times 3\times 3\) anti-symmetric tensor is separable.

摘要 : An interferometric measurement method is proposed to measure the Total Thickness Variation (TTV) and the Bow and Warp in the deformation of a double-sided polished wafer. Two phase-shifting Fizeau interferometers with reference mirrors are used to measure the topography of the front and back surfaces of the wafer simultaneously, and the measured topography of the front and back surfaces of the wafer are combined with the cavity topography of the two interferometers when the wafer is not placed to obtain the surface parameters of the double-sided polished wafer which are not affected by the reference mirror error. In the combined operation, the mapping error is introduced because the two reference mirrors are not precisely aligned, which affects the measurement results of the relevant parameters. To this end, before wafer measurement, the three-point positioning device is fixed between the two reference mirrors, and the position of the two reference mirrors is continuously adjusted based on the three-point circular theorem, which can make the mapping error extremely small, thereby reducing the influence of the mapping error on the measurement results. The experimental results show that the mapping errors of 50 mm wafer transverse and longitudinal directions are 21.592 μm and 37.480 μm, respectively, and the TTV, Bow and Warp are 0.198 μm, −0.326 μm and 1.423 μm, respectively. In order to further verify the effectiveness of the adjustment method, a single interferometer was used to flip the wafer for measurement, and the TTV, Bow and Warp of wafer are 0.208 μm, −0.326 μm and 1.415 μm, respectively. The proposed interferometric method can be easily and quickly used for the measurement of large quantities of large-sized wafers after adjusting the position of two reference mirrors, which improves wafer inspection efficiency. At the same time, it has a superior measurement accuracy.

摘要 : This letter addresses the problem of robust global predefined-time synchronization for a class of nonlinear systems, in which the settling-time is explicit compared with the conventional fixed-time synchronization. Specially, the designed control scheme is smooth, namely differentiable, which is distinguished from the traditional fast control methods containing the signum function. By the Lyapunov stability analysis, the sufficient criterion is derived for achieving the global predefined-time synchronization. More importantly, the obtained results have been directly applied into synchronizing two chaotic systems. Finally, the numerical simulation on predefined-time synchronization of chaotic systems is arranged for verifying the correction and effectiveness of theoretical results. © 2017 IEEE.

摘要 : With the widespread application of PPP in the construction field, the research on this topic has attracted considerable attention globally. A critical literature review, with comparison between the results from China and other countries, may facilitate a more comprehensive understanding of the research trend in various contexts. Based on a visual map analysis using the CiteSpace software, a total amount of 2399 pieces of PPP literature published in Chinese and international journals in 2008–2018 was screened and analyzed, in terms of the yearly number of publication, keyword cluster, keyword citation burst, as well as core institutions and authors. The main findings are: (1) The total amount of PPP literature has been increasing with 33.09% on average in the period investigated. In addition, the Chinese journals produced around five times of the publications in comparison to the international journals. (2) The Chinese PPP literature was focused more on the research theme of financing, whereas the international literature paid more attention to project management-related issues. (3) The collaboration between the international PPP research institutions was closer than the Chinese institutions. (4) The authors who contributed most of the Chinese PPP publications are the teams led by Mr. Jia from the Chinese Academy of Financial Sciences, and Professor Chan from the Hong Kong Polytechnic University in international publications. It was also suggested to conduct comparative research with a global perspective on PPP topic and to explore the application of modern technology in PPP projects to improve the management performance.

摘要 : Safety performance in the Chinese construction projects remains poor in comparison to other developed countries. While a considerable body of research has accumulated to explain why accident and incident rates remain high in China, research into safety climate in Chinese major construction projects remains scant. To address this gap in knowledge, a survey of 189 construction professionals across five major construction projects in China was undertaken using a validated safety climate framework. Follow-up interviews were also conducted with nine senior construction safety professionals to verify the survey analysis results. The findings indicate that safety climate in major construction projects in China is perceived to be strong, and management commitment appears to be the underlying factor to promote this positive result. Safety rules and procedures is a dimension that requires attention because of their complexity and competing interests during their implementation. All the dimensions of the safety climate are strongly interrelated, indicating that multidimensional and holistic strategies should be employed to improve safety climate in major construction projects. This research enriches the understanding about the characteristics of safety climate in Chinese major construction projects and the effective measures which can be taken to further enhance the safety performance on these projects.

摘要 : Determining soil categories in geotechnical engineering is critical to ensuring building safety, optimizing structural design, and controlling project costs. This study proposes a novel soil classification method based on an integrated machine-learning model. The integrated model synthesizes prediction results from four classification models, assigning weights to each model's probability outputs for various soil categories, then normalizes these aggregated probabilities to ensure that the predicted probabilities of the different soil categories add up to one, ultimately selecting the soil category with the highest normalized probability as the final classification. Initially, data from five distinct engineering projects located in Shanghai were collected, and 70% of data from each site was used to create a comprehensive dataset. It was then divided into training and testing datasets in a ratio of 8:2. Four classification algorithms, including decision tree, Random forest, KNN, and Adaboost, were trained using the training dataset. To enhance their collective predictive capability, Particle Swarm Optimization (PSO) was applied to fine-tune the weight coefficients among these models. The fitness function of PSO was defined as the integrated model's performance on the testing dataset. For the final stage of the study, the efficacy of the integrated model was subsequently validated using the remaining 30% of the data from each site. The experimental results show that the integrated model has high accuracy and robustness in multiple engineering sites compared with individual machine-learning models. In addition, the proposed integrated model exhibits significant superiority over traditional CPT-based direct methods. Overall, the integrated model shows accuracy and significant robustness across different project sites, highlighting its potential for application in geotechnical engineering. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.

摘要 : We present a method for designing a transmissive-reflective combined optical system to generate a focused ring-shaped laser beam. The design aims to achieve a freely adjustable radius for the focused ring-shaped laser beam and ensure uniform beam intensity even after defocusing. Based on the principle of equal energy splitting, the transmissive system establishes mapping functions for the input and output light projection height. It optimizes the lens parameters to shape the incident Gaussian light into a flat-topped circular shape, thus achieving uniformity of beam intensity. On the other hand, the reflective system uses the adjustable diameter range of the focal plane ring-shaped light and working distance parameters. By applying the principle of geometric ray tracing, it calculates the parameters of the conical reflecting mirror, parabolic cylindrical mirror, and dynamic mirror, then the flat-topped circular light is transformed into a ring-shaped light. The experimental results show that when the half-apex angle of the dynamic mirror is 16°, the designed system can achieve a freely adjustable radius for the focused ring-shaped laser beam from 15 mm to 30 mm with a size error not more than 0.05 mm, and the intensity uniformity after defocusing reaches 84%. The design method can achieve both uniformity of intensity and freedom of size adjustment without replacing the system lens. It has good operability and yields higher precision and efficiency in the processing of ring-shaped light.