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The paper aims to propose a novel dual-stage shape memory alloy (SMA) actuated gripper (DAG), of which the grasp performance is improved through primary and secondary actuation.

This paper presents a method of integrating the design of dual-stage actuation modules based on the SMA bias actuation principle to enhance the grasping shape adaptability and force modulation of a DAG. The actuation angle range and grasping performance of the DAG are investigated by thermomechanical analysis and the finite element method based numerical simulation.

The results of present experiments and simulations indicate that the actuation angle scope of the DAG is about 20° under no load, which enables the grasping space occupied by an object in the DAG from 60 mm to 120 mm. The grasping force adjusted by changing the input power of the primary main actuation module and secondary fine-tuning actuation module can reach a maximum of 2 N, which is capable of grasping objects of various sizes, weights, shapes, etc.

The contribution of this paper is to design a DAG based on SMA, and establish the solution methods for the primary main actuation module and secondary fine-tuning actuation module, respectively. It lays a foundation for the research of lightweight and intelligent robotic grippers.

The paper deals with the investigation of linear buckling and free vibration behavior of layered and multiphase magneto‐electro‐elastic (MEE) beam under thermal environment. The constitutive equations of magneto‐electro‐elastic materials are used to derive finite element equations involving the coupling between mechanical, electrical and magnetic fields. The finite element model has been verified with the commercial finite element package ANSYS. The influence of magneto electric coupling on critical buckling temperature is investigated between layered and multiphase magneto‐electro‐elastic beam. Furthermore, the influence of temperature rise on natural frequencies of magneto‐electro‐elastic beam with layered and different volume fraction is presented.

Mechatronics is a very important area of research in industrial applications. The purpose of this study is to find some of the most important components of the literature on this subject.

The analysis is based on the use of the database Compendex; it was searched in the broadest way for documents related to mechatronics. In addition, subject guides from libraries of universities with mechatronics programs were studied to find resources available in those areas.

The literature of mechatronics is extensive and multidisciplinary. Based on the results from Compendex, the following data were found: most productive authors, list of leading journals and conference proceedings, publishers and grant organizations, authors’ affiliations and other minor details. Based on the analysis of subject guides, the following types of resources were found: research databases, reference books and ebook collections.

Part of the analysis is based on a search performed in one technical database, Compendex; it was the database that generated the largest number of citations as compared to Inspec and the Web of Science. The results have a strong English language focus. It is possible that by using the results from multiple data bases, some additional sources could be obtained.

Mechatronics is a relatively new technological field comprising a number of scientific and engineering areas. The results obtained summarized a significant amount of bibliographic information.

The work is original; to the best of the authors’ knowledge, no other study has analyzed the literature on this subject.

Pipelines are subject to pits, holes and cracks after staying in service for a while, especially in harsh environments. To repair the pipelines, composite materials are used, due to composite materials' low cost, high-corrosion resistance and easy handling. This study aims to investigate the reliability of the blister test for evaluating the bonding strength of multiwall carbon nanotube (MWCNT) on woven carbon-reinforced epoxy.

Flexural, hardness and Izod impact tests were used to evaluate MWCNT effect on the epoxy by adding different amounts, 0.2, 0.4, 0.6, 0.8 and 1 wt. %, of MWCNT, to be compared with pure epoxy.

The results showed that 0.8 wt.% gives the highest strength. The experimental results of 0.8 wt.% MWCNT reinforced carbon composite was compared with the finite element model under blister test, and the results showed high similarities.

Evaluation of the reliability and the advantages of MWCNT considering the high aspect ratio and high tensile strength, which is more than 15 times compared to steel, MWCNT enhances the strength, stiffness and toughness of epoxy used as a matrix in repairing pipelines, which leads to an increase in the resistance of composite materials against oil internal pressure before delamination.

Some economic theories have influenced the reform of the socialist open economy with Chinese characteristics. As a new practice of socialism, an open economy is not only driven by China’s productivity level and people’s living standards but also regulated by the law of commodity production and value.

It was popular to participate in economic globalization for most countries in the second half of the 20th century, but not all of them could benefit from it.

The key to the success of the open-economy reform with Chinese characteristics lies in learning from and innovating the comparative advantage theory, thus forming an organic whole of the open economy, including the core of correctly handling the relationship between the government and the market, the method of gradual reform, the breakthrough point of transforming the mode of economic development, and serving people all the time.

Achieving internal and external coordination through the combination of opening-up and independence is a critical principle of China’s economic opening-up, which not only effectively safeguards national interests but also actively promotes the construction of a new global order.

A city is a spatial carrier of innovation activities. Improving the level of urban innovation can play a significant supporting role in building an innovative country. China began to implement the innovative city pilot policy in 2008 and continued to expand the policy into more areas for exploring the path of innovative urban development with Chinese characteristics and improving urban innovation.

Based on mechanism analysis, this paper used the panel data of 269 cities from 2003 to 2016 to empirically test the effect of the pilot policy on the level of urban innovation by using different methods, such as the difference-in-differences model.

The results show that the innovative city pilot policy significantly improves the level of urban innovation. However, according to the findings of the heterogeneity analysis, the effect of the pilot policy on improving the innovation level in direct-controlled municipalities, provincial capitals and sub-provincial cities is weaker than that in ordinary cities, and the effect of the pilot policy on improving the innovation level in cities with a higher quality of science and education resources is weaker than that in cities with lower quality of science and education resources.

Moreover, as the level of urban innovation increases, the effect of the pilot policy on improving the level of urban innovation is an asymmetric inverted V shape, which means the effect is first strengthened and then weakened. The research also finds that the locational heterogeneity of the pilot policy for improving the level of urban innovation is not notable. In addition, the innovative city pilot policy can strengthen the government's strategic guidance, promote the concentration of talent, incentivize corporate investment and optimize the innovation environment, having a positive impact on urban innovation. Moreover, the effect of concentration of talent and the effect of corporate investment incentive are the important reasons for the pilot policy to promote the improvement of the level of urban innovation.