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This paper aims to study the transient flow characteristics in a mixed-flow pump during the start-up period.

In this study, numerical calculation of the internal flow field in a mixed-flow pump using the sliding mesh method was carried out. The regulation of the pressure, streamline and the relative speed during the start-up period was analyzed.

The trend of the simulated head is consistent with the experimental results, and the calculated head is around 0.3 m higher than the experimental head when the rotation speed reached the stable stage, indicating that the numerical method for the start-up process simulation of the mixed-flow pump has a high accuracy. At the beginning, the velocity inside the impeller changes little along the radius direction and the flow rate increases slowly during the start-up process. As the rotation speed reached the stable stage, the flow inside the impeller became steady, the vortex reduced and transient effects disappeared gradually.

The study results have significant value for revealing the internal unsteady flow characteristics of the mixed-flow pump and providing the reference for the design optimization of the mixed-flow pump.

Under the background of economic and technological globalization, all countries will pay attention to science and technology innovation policies. At this time, the era of innovation policy plays an important role. In order to thoroughly implement the spirit of the 19th National Congress of the Communist Party of China, earnestly innovate development concepts and strengthen the key supporting role of scientific and technological innovation for social development.

The research will make an in-depth study on the policy of scientific and technological innovation, take the change trend of the number of laws and regulations and the analysis of the basic content as the entry point, and classify it from five different aspects, such as the policy of scientific and technological system and mechanism, the policy of financial guidance, the policy of technological innovation of enterprises, the policy of scientific and technological talents, and the policy of intellectual property.

Through the comparison of the development history of science and technology policies at home and abroad, the development history of science and technology innovation policies under the special national conditions of China is obtained. Combining with the relevant basic theories of science and technology innovation system, designing from the publishing department, main content, and implementation subject, constructing a synergistic science and technology innovation system of “government, industry, university and research,” and forming an “integration of supply and demand” technology innovation framework will guide the development of China's science and technology innovation in the future.

The authors construct the policy framework of science and technology collaborative innovation based on the concept of science and technology innovation policies. The framework has realistic significance for its future development.

The purpose of this paper is to perform a systematic review on the application of different multi-criteria decision-making (MCDM) methods in solving the site selection problem across multiple problem domains. The domains are energy generation, logistics, public services and retail facilities. This study aims to answer the following research questions: Which evaluating criteria were used for each site selection problem domain? Which MCDM methods were frequently applied in a particular site selection problem domain?

The goals of the systematic review were to identify the evaluating criteria as well as the MCDM method used for each problem domain. A total of 81 recent papers (2014–2018) including 32 papers published in conference proceedings and 49 journal articles from various databases including IEEE Xplore, PubMed, Springer, Taylor and Francis as well as ScienceDirect were evaluated.

This study has shown that site selection for energy generation facilities is the most active site selection problem domain, and that the analytic hierarchy process (AHP) method is the most commonly used MCDM method for site selection. For energy generation, the criteria which were most used were geographical elements, land use, cost and environmental impact. For logistics, frequently used criteria were geographical elements and distance, while for public services population density, supply and demand, geographical layout and cost were the criteria most used. Criteria useful for retail facilities were the size (space) of the store, demographics of the site, the site characteristics and rental of the site (cost).

This study is limited to reviewing papers which were published in the years 2014–2018 only, and only covers the domains of energy generation, logistics, public services and retail facilities.

MCDM is a viable tool to be used for solving the site selection problem across the domains of energy generation, logistics, public services and retail facilities. The usage of MCDM continues to be relevant as a complement to machine learning, even as data originating from embedded IoT devices in built environments becomes increasingly Big Data like.

Previous systematic review studies for MDCM and built environments have either focused on studying the MCDM techniques itself, or have focused on the application of MCDM for site selection in a single problem domain. In this study, a critical review of MCDM techniques used for site selection as well as the critical criteria used during the MCDM process of site selection was performed on four different built environment domains.