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For the structural design of cable domes, the determination of prestress force distribution, the section of the structural components, and initial configuration are prerequisites for the subsequent detailed design of cable and strut sizes. To solve this problem, this paper elucidates the basic theory of the Minor Perturbation Method, introduces this theory into the field of force finding design for cable dome structures, and develops a new design method whose core is the comparison between the combined stress of each component conforming to mechanical characteristics of cable-strut structure and control stress, and meeting the convergence condition by adjusting the prestress level and cross-section of components. A corresponding design flow chart is established and programmed with finite element analysis software. Through the case studies of two different kinds of cable dome, it is proven that the proposed method and software program can simply, quickly, and effectively design the cable domes with an economic cross-section.

This study introduces a multi-point optical flow cable force measurement method based on Euler motion amplification to address challenges in accurately measuring cable displacement under small displacement conditions and mitigating background interference in complex environments. The proposed method combines phase-based magnification with an optical flow method to enhance small displacement features and improve SNR (signal-to-noise ratio) in cable displacement tracking. By leveraging magnified motion data and integrating auxiliary feature points, the approach compensates for equipment-induced vibrations and background noise, allowing for precise cable displacement measurement and the identification of vibration modes. The methodology was validated using a scaled model of a cable net structure. The results demonstrate the method’s effectiveness, achieving a significantly higher SNR (e.g., from 7.5 dB to 22.24 dB) compared to traditional optical flow techniques. Vibration frequency errors were reduced from 6.2% to 1.5%, and cable force errors decreased from 11.38% to 3.13%. The multi-point optical flow cable force measurement method based on Euler motion magnification provides a practical and reliable solution for non-contact cable force measurement, offering potential applications in structural health monitoring and the maintenance of bridges and high-altitude structures.

Based on the original construction experiences and techniques of cable dome, the method of integral assembling on the ground and synchronous hoisting of the structure of cable dome is firstly put forward. With the cable dome built in Ordos, the integral hoisting method and tension-shaping technique are put into effect. The results indicated the integral hoisting method can reduced aerial work and guaranteed constriction security.

Transboundary pollution poses a major threat to environment and human health. An effective approach to addressing this problem is the adoption of long-term abatement technology; however, many developing regions are lacking in related technologies that can be acquired by licensing from developed regions. This study focuses on a differential game model of transboundary pollution between two asymmetric regions, one of which possesses advanced abatement technology that can reduce the abatement cost and licenses this technology to the other region by royalty or fixed-fee licensing. We characterize the equilibrium decisions in the regions and find that fixed-fee licensing is superior to royalty licensing from the viewpoint of both regions. The reason is that under fixed-fee licensing, the regions can gain improved incremental revenues and incur reduced environmental damage. Subsequently, we analyze the steady-state equilibrium behaviors and the effects of parameters on the licensing performance. The analysis indicates that the myopic view of the regions leads to short-term revenue maximization, resulting in an increase in total pollution stock. Moreover, a high level of abatement technology or emission tax prompts the licensee region to choose fixed-fee approach, which is beneficial both economically and environmentally for two regions.

Lithium carbonate plays a critical role in both lithium-carbon dioxide and lithium-air batteries as the main discharge product and a product of side reactions, respectively. Understanding the decomposition of lithium carbonate during electrochemical oxidation (during battery charging) is key for improving both chemistries, but the decomposition mechanisms and the role of the carbon substrate remain under debate. Here, we use an in-situ differential electrochemical mass spectrometry-gas chromatography coupling system to quantify the gas evolution during the electrochemical oxidation of lithium carbonate on carbon substrates. Our results show that lithium carbonate decomposes to carbon dioxide and singlet oxygen mainly via an electrochemical process instead of via a chemical process in an electrolyte of lithium bis(trifluoromethanesulfonyl)imide in tetraglyme. Singlet oxygen attacks the carbon substrate and electrolyte to form both carbon dioxide and carbon monoxide—approximately 20% of the net gas evolved originates from these side reactions. Additionally, we show that cobalt(II,III) oxide, a typical oxygen evolution catalyst, stabilizes the precursor of singlet oxygen, thus inhibiting the formation of singlet oxygen and consequent side reactions. Lithium carbonate is ubiquitous in lithium battery chemistries and leads to overpotentials, however its oxidative decomposition is unclear. Here, the authors study its decomposition in ether electrolyte, clarify the role of the carbon substrate, and propose a route to limit released singlet oxygen.

The accuracy of optical flow estimation algorithms has been improving steadily as evidenced by results on the Middlebury optical flow benchmark. The typical formulation, however, has changed little since the work of Horn and Schunck. We attempt to uncover what has made recent advances possible through a thorough analysis of how the objective function, the optimization method, and modern implementation practices influence accuracy. We discover that “classical” flow formulations perform surprisingly well when combined with modern optimization and implementation techniques. One key implementation detail is the median filtering of intermediate flow fields during optimization. While this improves the robustness of classical methods it actually leads to higher energy solutions, meaning that these methods are not optimizing the original objective function. To understand the principles behind this phenomenon, we derive a new objective function that formalizes the median filtering heuristic. This objective function includes a non-local smoothness term that robustly integrates flow estimates over large spatial neighborhoods. By modifying this new term to include information about flow and image boundaries we develop a method that can better preserve motion details. To take advantage of the trend towards video in wide-screen format, we further introduce an asymmetric pyramid downsampling scheme that enables the estimation of longer range horizontal motions. The methods are evaluated on the Middlebury, MPI Sintel, and KITTI datasets using the same parameter settings.

This work proposes a topology optimization design method of metamaterials for improving the vibration reduction performance. Firstly, an optimization mathematical model of the functional element is established with the objective of maximizing the origin mechanical impedance level, and the functional element with optimal vibration reduction effect is obtained by the calculation of the mathematical model. Then, the optimized functional elements are periodically arranged to generate the metamaterials, and thus a series of metamaterials with negative Poisson’s ratio ranging from − 0.5 to − 2.0 are designed. Numerical simulation shows that the amplitudes of the acceleration response are reduced by 66.5% after the vibration is passed through the metamaterials. Comparison shows that the novel designed metamaterials achieve at least 12% improvement in vibration reduction performance over the traditional honeycomb.

To further clarify the relationship between environmental regulation and green technology innovation and discuss how environmental regulation affects green technology innovation through import trade, this paper analyzes the impacts of environmental regulation and import trade on green technology innovation and the transmission effect of import trade based on panel data for 30 provinces in China for 2008 to 2017. The results show that (1) environmental regulation first plays a role in promoting green technology innovation and then restrains it, and import trade can significantly promote green technology innovation; (2) under the constraints of stronger environmental regulations, import trade has a significantly positive effect on green technology innovation; and (3) environmental regulation can further enhance the technology spillover effects of import trade in regions with high absorptive capacity and regions with high levels of R&D investment. This paper analyzes the impact of environmental regulation on green technology innovation from the perspective of import trade and makes up for the deficiencies of existing research. It also lays a foundation for scholars to study the relationship between environmental regulation and green technology innovation in the midst of heterogeneous government regulation capabilities and industries in the future.

A preliminary study of the mechanical properties of auxetic cellular material consisting of re-entrant hexagonal honeycombs is presented. For different scales of the honeycombs, the finite element method (FEM) and experimental models are used to perform a parametric analysis on the effects of the Poisson’s ratio (cell angle) and the relative density (cell thickness) of honeycombs on bearing capacity and dynamic performance of the auxetic material. The analysis demonstrates that the ultimate bearing capacity of the presented auxetic cellular material is scale-independent when the Poisson’s ratio and the relative density are kept constant. The relationship between the geometric parameters and vibration level difference of the honeycombs is also revealed, which can be divided into two converse parts around the Poisson’s ratio v = − 1.5 . When v is smaller than −1.5, increasing the cell thickness leads to an increase in the vibration level difference of the honeycombs. Moreover, the dynamic performance of thin-walled honeycombs is greatly influenced by the scale of the honeycombs, especially for the ones with small Poisson’s ratio. These conclusions are verified by a frequency response test and a good agreement between the numerical results and experimental data is achieved.

Supply chain members’ reciprocal altruism and consumers’ quality and service reference effects are important behavioral factors that affect the decision-making of supply chain members. This article incorporates these factors into a product–service supply chain consisting of a manufacturer and a retailer in the online-to-offline (O2O) environment. Based on the inherent dynamics of the model, we construct a differential game model between the manufacturer and the retailer. Based on the Bellman continuous dynamic programming theory, this study analyzes the quality strategy of the manufacturer, the service level strategy of the retailer, and the performance of the supply chain system under three decision-making patterns (decentralization, centralization, and reciprocal altruism) within the O2O framework. The results show that compared with the decentralized decision-making model, reciprocal altruism helps members develop higher quality and service levels, improve brand goodwill, and obtain greater utility. The results are verified by numerical examples, and sensitivity analysis of consumer quality and the service reference effect, channel preference, and members’ reciprocal altruism behavior on the supply chain performance is carried out. The results show: (1) Consumers’ reference effects cause an “anchoring mentality” among consumers, which leads the manufacturer to lower the quality level and the retailer to lower the service level. This hurts the performance of the product–service supply chain. Consumers’ channel preference has an important impact on supply chain members’ strategies and performance. (2) Retailers should encourage consumers to purchase products online and use offline channel services as sales assistance measures to satisfy consumers’ experience utility. (3) As a positive social preference, the supply chain performance under the members’ reciprocal altruism decision-making model is Pareto-improved and receives additional social benefits. (4) Only when the manufacturer and the retailer have pure altruistic preference, that is, minimum return and maximum altruism, the total profit of the supply chain can reach that of the centralized decision-making scenario.