Volume 24

Michael addition reaction refers to the conjugate addition reaction of carbocation to α, β-unsaturated aldehydes, ketones, carboxylic acids, esters, nitrile, nitro compounds, etc. The reaction is an essential organic reaction, and it is used in organic synthesis to grow carbon chains and synthesize organic compounds with various functional groups. As one of the most valuable organic synthesis reactions, it is one of the most common ways to construct carbon-carbon bonds. This paper analyzes the mechanisms and the theories of some common Michael addition reactions. It also includes an example of the research of Michael addition in recent years. In a recent study, a research team experimentally found a suitable catalyst to catalyze the Michael addition reaction on benzyl groups, and obtained the different performances of benzyl groups with different functional groups during addition. Cyclopentadienyl rhodium catalyst has excellent catalytic activity and selectivity for benzyl first, second, and third C/H bonds. The reaction can be compatible with halogen, ester, and amide functional groups.

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The wide usage of microplastics and heavy metals has led to the accumulation of these pollutants in our environment. Among heavy metals and microplastics, Cadmium (Cd), polyvinyl chloride (PVC), and polyethylene (PE) are the most severe and ubiquitous pollutants. With large surface areas, microplastics have the ability to absorb metal ions, potentially performing "carrier effect", by which microparticles enhance the transfer of other pollutants from soil to plants. Phytoextraction has been shown to be the most effective strategy to remediate heavy metal contamination. In this study, we selected Galinsoga quadriradiata (G. quadriradiata) as the test species to investigate the effectiveness of phytoextraction in soil contaminated with Cd, PVC and PE. According to our results, G. quadriradiata present effective phytoextraction to Cd and microplastics. However, the carrier effect between Cd and PVC or PE only exists in the value of maximal quantum efficiency of photosystem II (Fv/Fm) but has no effect on the uptake of Cd by G. quadriradiata. For future studies, we propose to investigate the carrier effect between heavy metals and microplastics in plants, test the pathway of microplastics by which they are up-taken by plants from soil, and increase the efficiency of phytoextraction by exposing plants (such as G. quadriradiata) that have been proved to absorb heavy metal to microplastics.

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The seismic vulnerability analysis is of great important for the design, operation and maintain. The selected extra-large highway and railway dual-used arch bridge contains high geometric nonlinearity and is one of the transportation junctions. Therefore, it is necessary to conduct seismic response analysis. The research results can provide reference for the seismic design and seismic response analysis of target bridge and similar typed bridges. Thus, it has high theoretical value for the design and promotion of similar bridges. This paper starts with a theoretical analysis, using the finite element software LS-DYNA to build a dynamic calculation model of the real bridge and carry out modal and time response analyses. The strength, vulnerable components and stability of the bridge under three-way seismic action at for different earthquake excitation waves (Wenchuan earthquake, Chichi earthquake, Kobe earthquake and El-Centro earthquake) are investigated. Through analysis and comparison of numerical calculations, the seismic performance of the target bridge was comprehensively evaluated.

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With the rapid development of building level and construction technology, high-rise buildings have been adopted more and more, thus becoming an important place for people to work and live. Because of the high height of high-rise buildings, wind load becomes the main resultant force type of high-rise building. However, wind load has great randomness and unpredictability, which has great influence on the stability of high-rise building. This paper first analyses the main characteristics of wind load borne by tall buildings. Then, the common methods of wind-resistant design of high-rise building are summarized in detail. It also points out the existing problems and deficiencies in wind resistance design of high-rise buildings and the countermeasures and suggestions of wind resistance design of high-rise structures. Finally, according to the current research status and existing problems, the future development of wind resistance design is prospected. Results can provide some references for wind resistance design and research of high-rise buildings.

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With the development of modern engineering technology, more attention is paid to the aid of digitization and information in the process of engineering project design and construction. Building Information Model (BIM) realizes the transformation from traditional building project to modern building project. At the same time, it also greatly promotes the digital development of construction projects. BIM technology as a modern information technology in the application of construction engineering, has a variety of benefits. For example, it can improve the quality of projects. In addition, the application of BIM technology in the whole process of construction projects can reduce costs and improve efficiency. However, there are many risks associated with using BIM in construction projects. This paper analyzes the advantages of BIM technology in visualization and coordination, and the application of BIM in design, construction, management and other aspects. Then, the risks and countermeasures in BIM application are discussed. The research results are of great significance to improve the informatization level of construction projects.

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Building construction involves many complex processes such as high-altitude operations, mechanized equipment operations, and transportation and handling of building materials. Construction is a high-risk industry with frequent accidents. Therefore, some efficient and practical preventive measures need to be proposed immediately to reduce the occurrence of these accidents. This paper introduces different types of construction accidents and analyzes the reasons in combination with the theory of accident causation, to provide implementable ways to improve the safety performance of construction projects. Finally, a few precautions are offered in this paper to prevent the similar accidents from happening. The research results show that measures such as improving the safety evaluation system, strengthening the operating environment, strictly controlling the installation and dismantling links, enhancing the lighting conditions at night, and controlling minor accidents can effectively prevent the occurrence of construction safety accidents.

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As the population and urbanization have continued to grow all over the world, the construction industry demands more efficient, and greener ways of building. In recent years, prefabricated buildings have attracted widespread attention as a new construction method. BIM technology is a crucial element in the realm of digital architectural design and construction. Its implementation can effectively enhance the support and optimization of the prefabricated building's design and construction process. This paper aims to explore the application of BIM technology in the design and construction stages of prefabricated buildings. Firstly, the utilization of BIM technology in prefabricated building design is expounded from three aspects of digital model construction, architectural collaborative design and architectural design optimization. Then, the implementation of BIM technology in prefabricated building construction is analyzed with regard to three aspects: development of construction plans, on-site management, and quality control. Subsequently, the application of BIM technology in the design of high-rise prefabricated buildings and the construction of prefabricated buildings is introduced in detail through case studies. The results show that the application of BIM technology can improve the design efficiency and construction quality of prefabricated buildings, and has a good application prospect.

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Building Information model (BIM) is a kind of digital building information model. Through BIM technology, building information can be presented to each department of building engineering in the form of three dimensional (3D). In traditional building information management, design part and construction part are independent of each other. There is no unified standard and information management system between the two sides. As a result, the construction information between the design department and the construction department cannot be shared in time, and both sides are prone to make mistakes in the negotiation of construction issues. These mistakes not only delay the construction, but also increase the construction cost. With the development of BIM technology, each department of building can understand the details of the building more intuitively through the building information model. Designers and builders can communicate effectively in construction projects and coordinate problems in the construction process.

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Nowadays civil engineering is facing the transformation of the combination of intelligent, digital and other modern new technologies. Civil engineering, as a traditional industry, may not be able to meet the efficiency and requirements of today's technological society. In order to adapt to the development of society, civil engineering is trying to transform to other disciplines. In recent decades, intellectualization and digitization have begun to affect the way civil engineering works and operates. In fact, intellectualization and digitalization can affect every stage of the whole civil engineering process, including the design stage, construction stage and service stage. The purpose of this paper is to discuss the application of intelligence and digitization in civil engineering. Some of the most important applications are listed and further explained, and the future development prospect is preliminarily analyzed and prospected. By enumerating the innovation brought by intelligence and digitalization to civil engineering, it inspires people to carry on more in-depth thinking, further adaptation and new adjustment to the future civil engineering.

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With the continuous progress of China's urbanization, problems such as rainwater runoff pollution, flood disaster and water resource shortage have become increasingly prominent. Sponge city is a good way to solve urban waterlogging and improve the water ecological environment. This paper first describes the water resources issues encountered by Chinese cities, and then it explains the significance of sponge city building, in order to further apply the idea of water ecological civilization construction and promote the construction of sponge city. China's creation of sponge cities is still in its early stages when compared to Western nations. In this paper, the effectiveness of the construction of Jiaozuo sponge city is examined together with the research state of sponge city construction in China. Finally, this paper discusses some problems in the process of sponge city construction and puts forward some concrete suggestions. It is expected to play a reference role in promoting the development of sponge city and improving the construction of sponge city in China.

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