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The exploration of the polar regions is of immeasurable potential. It brings great challenges to tribology in the extreme environment. Moreover, the static friction force is an essential index of the braking performance. The purpose of this paper is the static friction force between the rubber of marine pipe tensioner and the ice bead.

The frictional phenomena were studied for rubber-ice bead at different contact positions (front edge, front part and end part) by means of image processing and measuring. Also, the image sequences of the contact were combined with friction force and displacement data.

As rubber across the ice bead, the forces of rubber and ice bead at different contact positions determined the order of static friction force (front edge > front part > end part). Meanwhile, there were two different contact states in this process. In addition, under the low tangential load growth rate, the higher temperature can increase the static friction force by increasing the viscoelasticity and contact area of rubber.

The research on the static friction of rubber-ice bead leads to more controlled and higher friction levels during marine pipeline laying.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0526/

In the context of exploring and implementing China's new urbanization, green eco-city have become a transformation model for urban development. Sharpening green buildings in the construction industry can significantly influence and determine China's economic growth trends, as well as the growth and overall development of its national economy. However, current green eco-city still lack appropriate standards and scientific theoretical basis to determine the target star program of green buildings. To fully implement the green building standards, establish and improve a sound technical standard system for the construction of green building demonstration areas, this study considers the spatial layout of green buildings as the core, adopts a plot potential evaluation method for evaluating a few green building plots, and utilizes four factors in verifying plots with great star potential. The study also establishes a system to calculate the star proportion of green buildings and applies the system in calculating the green building ratio of GM New District. Results indicate that the system can quantitatively analyze a plot potential, calculate the star proportion of green buildings scientifically and rationally, and provide some references for the construction of eco-city and the preparation of special planning for green buildings. The system construction is conducive to provide technical support for the construction of green eco-city. The improved system can be applied in the green building demonstration areas in China, and will be a reference model of constructing green building demonstration areas in the country.

Visitor center plays an important role in the normal operation and sustainable development of scenic spots, especially as a portal image of its management. This paper presents resilience theory for visitor centers to identify some common issues in designing visitor centers in China scenic spots, including the lack of function, loss of architectural characteristics, and difficultly in adapting to changes in the number of visitors with periodic variations. The framework of resilience theory was set from four dimensions, namely, resilience and match in the composition of ontology function, the extended function, integration of buildings into the surrounding environment, and alternative construction technologies and materials. This theory was explained and analyzed with the application of the theory in practice in combination with the design of Mount Hua visitor center. Results showed that resilience theory yields good application effect.

The paper aims to propose a generation approach for unstructured surface mesh to speed up mesh generation.

The paper proposes a lightweight interactive generation approach for unstructured surface mesh and presents several key technologies to support this approach.

The experimental results show that the proposed approach is feasible for unstructured meshes and it can accelerate the mesh generation process.

More geometric defects should be covered, and more convenient and efficient interactive means need to be provided.

The proposed approach and key technologies are implemented in NNW-GridStar.UG, which is the unstructured version of the mesh generation software of National Numerical Windtunnel (NNW).

This paper proposes a lightweight interactive approach for unstructured surface mesh generation, which can speed up mesh generation.

Majority of the existing direct slicing methods have generated precise slicing contours from different surface representations, they do not carry any interior information. Whereas, heterogeneous solids are highly preferable for designing and manufacturing sophisticated models. To directly slice heterogeneous solids for additive manufacturing (AM), this study aims to present an algorithm using octree-based subdivision and trivariate T-splines.

This paper presents a direct slicing algorithm for heterogeneous solids using T-splines, which can be applied to AM based on the fused deposition modeling (FDM) technology. First, trivariate T-splines are constructed using a harmonic field with the gradient direction aligning with the slicing direction. An octree-based subdivision algorithm is then used to directly generate the sliced layers with heterogeneous materials. For FDM-based AM applications, the heterogeneous materials of each sliced layer are discretized into a finite number of partitions. Finally, boundary contours of each separated partition are extracted and paired according to the rules of CuraEngine to generate the scan path for FDM machines equipped with multi-nozzles.

The experimental results demonstrate that the proposed algorithm is effective and reliable, especially for solid objects with multiple materials, which could maintain the model integrity throughout the process from the original representation to the final product in AM.

Directly slicing heterogeneous solid using trivariate T-splines will be a powerful supplement to current technologies in AM.

Analyses the evolution of China’s telephone and cable systems, in terms of the public interest, discussing current bureaucratic conflicts and policy debates over convergence, and construction of an independent broadband cable network. Looks in depth at China’s problems and the different problems for its citizens with regard to poverty levels and access to the Web.

This study aims to fabricate the reduced graphene oxide (rGO)/ethylene vinyl acetate copolymer (EVA) composite films with electric-driven two-way shape memory properties for deployable structures application. The effect of dicumyl peroxide (DCP) and rGO on the structure and properties of the rGO/EVA composite films were systematically investigated.

The rGO/EVA composite films were fabricated by melting blend and swelling-ultrasonication method, DCP and rGO were used the crosslinking agent and conductive filler, respectively.

The research results indicate that the two-way shape memory properties of rGO/EVA composite films were significantly improved with the increase of DCP content. The rGO endowed rGO/EVA composite films with excellent electric-driven reversible two-way shape memory and anti-ultraviolet aging properties. The sample rGO/EVA-9 can be heated above Tm within 8 s at a voltage of 35 V and can be heated above the Tm temperature within 12 s under near-infrared light (NIR). Under a constant stress of 0.07 MPa, the reversible strain of the sample rGO/EVA-9 was 8.96% and its electric-driven shape memory behavior maintained great regularity and stability.

The rGO/EVA composite films have potential application value in the field of deployable structures.

With the increase of DCP content, the two-way shape memory properties of rGO/EVA composite films were significantly improved, which effectively solved the problem that the shape memory properties of EVA matrix decreased caused by swelling. The rGO endowed rGO/EVA composite films with excellent electric/NIR driven reversible two-way shape memory properties.

The purpose of this paper is to determine (1) the relationship between microstructure and fatigue cracking behavior and (2) effect of rolling on the process of crack initiation and propagation in FeCrAl alloys.

The qualitative and quantitative fracture studies were performed using scanning electron microscopy and the non-contact optical measurement system (IFMG5).

The results show that the formation of facets, rough facets and parallel stripes in the crack initiation and early crack propagation zones are closely related to the sensitivity of crack behavior to the microstructure of the material. Besides, the rolling process has a significant influence on the small crack initiation and propagation behavior. Quantitative analysis demonstrates that the size of the stress intensity factor and plastic zone size in the rough zone is associated with the rolling process.

The findings of this study have the potential to enhance the understanding of the microstructural crack formation mechanisms in FeCrAl alloys and shed light on the impact of rolling on the long-term and ultra-long fatigue behavior of these alloys. This new knowledge is vital for improving manufacturing processes and ensuring the safety and reliability of FeCrAl alloys used in nuclear industry applications.

The aim of this study is to investigate the horizontal displacement effects of foundation pit excavation on adjacent metro stations and shield tunnel composite structures. It seeks to develop a theoretical calculation method capable of accurately assessing these engineering impacts, aiming to provide practical assistance for engineering applications.

This study introduces a model for shield tunnel segments incorporating rotation and misalignment, considering the constraints of metro stations. It establishes a displacement model for tunnel-station combinations during foundation pit excavation, deriving a formula for calculating station-proximal tunnel horizontal displacements. The method's accuracy is validated against field data from three engineering cases. The research also explores variations in tunnel displacement, inter-ring shear force, misalignment and rotation angle under different spatial relationships between pits, tunnels and stations.

This study models uneven deformation between stations and tunnels due to bending stiffness and shear constraints. It enhances the misalignment model with station-induced shear effects and introduces coefficients for their mutual interaction. Results show varied responses based on pit-station-tunnel positioning: minimal displacement near pit edges (coefficients around 0.1) and significant effects near pit centers (coefficients from 0.4 to 0.5). “Whip effect” from station constraints affects tunnel displacement, shear force, misalignment and rotation, with fluctuations decreasing with distance from excavation areas.

This study demonstrates significant originality and value. It introduces a novel displacement model for tunnel-station combinations considering station constraints, addressing theoretical calculations of horizontal displacement effects from foundation pit excavation on metro stations and shield tunnel structures. Through validation with field data and parameter studies, the concept of influence coefficients is proposed, offering insights into variations in structural responses under different spatial relationships. This research provides crucial technical support and decision-making guidance for optimizing designs and facilitating practical construction in similar engineering projects.

While the Chinese securities market is booming, the phenomenon of listed companies falling into financial distress is also emerging, which affects the operation and development of enterprises and also jeopardizes the interests of investors. Therefore, it is important to understand how to accurately and reasonably predict the financial distress of enterprises.

In the present study, ensemble feature selection (EFS) and improved stacking were used for financial distress prediction (FDP). Mutual information, analysis of variance (ANOVA), random forest (RF), genetic algorithms, and recursive feature elimination (RFE) were chosen for EFS to select features. Since there may be missing information when feeding the results of the base learner directly into the meta-learner, the features with high importance were fed into the meta-learner together. A screening layer was added to select the meta-learner with better performance. Finally, Optima hyperparameters were used for parameter tuning by the learners.

An empirical study was conducted with a sample of A-share listed companies in China. The F1-score of the model constructed using the features screened by EFS reached 84.55%, representing an improvement of 4.37% compared to the original features. To verify the effectiveness of improved stacking, benchmark model comparison experiments were conducted. Compared to the original stacking model, the accuracy of the improved stacking model was improved by 0.44%, and the F1-score was improved by 0.51%. In addition, the improved stacking model had the highest area under the curve (AUC) value (0.905) among all the compared models.

Compared to previous models, the proposed FDP model has better performance, thus bridging the research gap of feature selection. The present study provides new ideas for stacking improvement research and a reference for subsequent research in this field.