Many super high-rise buildings emerge in modern cities with urban development, facilitating work, accommodations, etc. However, their safety risks and accidents due to the wind are urgent problems with the complex flow field in cities. The research on wind loads of super high-rise buildings is thus crucial, but most studies tend to consider only the influence of the surrounding single-scale building clusters, rarely considering multi-scale ones. In this paper, the influence of the surrounding multi-scale building clusters on the wind loads of a super high-rise building is investigated. The wind field of a super high-rise building surrounded by four different arrangements of idealized, simplified buildings is first simulated using computational fluid dynamics (CFD) methods: RANS and Hybrid LES/RANS models. It is found that surrounding tall buildings can significantly affect the pressure distribution on the windward and leeward sides of the super high-rise building, such as fluctuating, extreme, and mean wind pressure. The vortex, formed largely due to short buildings, increases the negative pressure at the back of the super high-rise building. In addition, simulations are conducted for the wind field around the CITIC Tower in Beijing CBD, and it is found that the flow field of the actual building group is more complex due to the strong interactions between buildings, and the flow near the ground is even more complex. All simulation results are validated by the wind tunnel tests. This study can provide important guidance for the wind safety design of super high-rise buildings and the future planning of urban buildings.

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.

In order to solve the restrictions on athletes and the time and cost of equipment replacement caused by traditional sports equipment, which are easy to corrode, have short service life, poor mechanical properties, and are relatively heavy, etc., more excellent polymer materials and new materials are used in various aspects. technology to replace traditional materials. At the same time, the diversified characteristics of polymer materials can provide more types of choices for various sports equipment. In order to understand the application and influence of polymer composite materials in competitive sports, the application of polymer compounds is analyzed in combination with the preparation process in this paper, material performance and performance requirements of sports equipment. By comparing the performance of athletes in different eras without using the same equipment and the length of their competitive career, this paper concluded that the application of polymer composite materials in competitive sports has greatly improved the performance of athletes and reduced the risk of injury , It also increases convenience and safety for ordinary people.

The lithium-ion battery has become one of the most widely used green energy sources, and the materials used in its electrodes have become a research hotspot. There are many different types of electrode materials, and negative electrode materials have developed to a higher level of perfection and maturity than positive electrode materials. Enhancing the electrochemical capabilities of positive electrode materials is therefore crucial. In addition to exploring and choosing the preparation or modification methods of various materials, this study describes the positive and negative electrode materials of lithium-ion batteries. Among the negative electrode materials, Li4Ti5O12 is beneficial to maintain the stability of the battery structure, and the chemical vapor deposition method is the best way to prepare nitrogen-doped graphene materials. Doping and coating modifications for positive electrode materials can offer a smoother mobile route for lithium ions, which can enhance the cathode material’s cycling performance. This paper’s study, summary, and outlook on electrode materials for lithium-ion batteries can aid those researchers in developing a more thorough understanding of electrode materials. Also, it can be advantageous for the growth of associated follow-up research projects and the expansion of the lithium battery market.

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.

One of the most important things that affect people’s lives is transit. Everyone relies on transit to go to different places. Due to a high amount of private car ownership in the city, traffic jams start to occur. Then, demands start to show up on public transit. Lots of people nowadays rely on public transit to go to different places. Therefore, a small modification on a transit line could affect a massive number of residents. To build an accessible and eco-friendly transit has always been a goal for most of the city governments and agencies. In this essay, some factors that affect modern transit and people’s intention to ride transit in Shanghai will be discussed. Shanghai’s different transit factors, including private cars ownership, public transit coverage, and eco-friendly fleet rate will be compared among two other similar cities globally. Some suggestions on different dimensions of transit will be given to help Shanghai to build a greener and more efficient transit, to reduce the air pollution and traffic congestion.

The primary issue with concrete structures is steel bar corrosion. Therefore, FRP (Fiber Reinforced Polymer) bars are often to substitute steel bars to tackle the issue of concrete swelling and cracking brought about by steel corrosion. FRP bars’ feature improved corrosion resistance, a stronger strength-to-quality ratio, and better fatigue resistance. However, the alkaline environment will affect the long-term strength and durability of FRP, according to certain research, which will cause the FRP bars’ mechanical characteristics to deteriorate. In this paper, the properties of FRP bars under alkaline conditions are reviewed, considering the harsh external environment and physical properties of FRP bars. Comprehensive investigation concludes that lowering the PH value of concrete and changing the kind of fiber material may considerably increase the endurance of FRP in alkaline environments. By demonstrating the microscopic breakdown process of FRP bars in an alkaline conditions using scanning electron microscopy. The Arrhenius acceleration theory was used to construct the present model for forecasting the long-term mechanical behavior of FRP bars, which shows how this material degrades under alkaline circumstances. This study may be utilized as a reference for FRP bars used in alkaline environments in terms of durability studies.

With the rapid development of new energy battery field, the repeated charge and discharge capacity and electric energy storage of battery are the key directions of research. Therefore, the selection standards of electrode materials and electrolyte are continuously improved, ordinary battery materials can no longer meet the needs of development. As a new type of material, nanomaterials have been widely used in many industries due to their special structure and properties. Similarly, nanomaterials also provide new possibilities for the development of new energy batteries. This paper mainly explores the different applications of nanomaterials in new energy batteries, focusing on the basic structural properties and preparation methods of nanomaterials, as well as the applications of different nanomaterials in the positive and negative materials of new energy batteries, and forecasts the future development direction of this industry. This paper is expected to provide ideas for the research of nanomaterials and new energy batteries, and promote the national research on new batteries.

As the lithium-ion battery market continues to expand so far, the number of spent lithium-ion batteries continue to increase, and its impact on the environment cannot be ignored. It is of great necessity to find out a scientific and effective process to recycle spent lithium-ion batteries (LIBs). Starting from the specific pollution of each part of LIBs to the environment, this paper expounds the recycling methods and emerging technologies of cathode materials with the largest proportion and the highest economic value. This paper believes that from the pre-treatment of spent LIBs, and then goes through whether it is thermometallurgy, hydrometallurgy or direct regeneration, each step of recovery process has its own use scenarios. There are still certain problems in industrial applications, recovery rate, safety, secondary pollution and other aspects. Some technologies such as bio-leaching are yet to be developed and are expected to be widely used in the near future. This paper looks forward to a more comprehensive development and breakthrough in the recycling technology of LIBs in the future, rather than being limited to cathode materials.

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.

GaN is a third-generation semiconductor. As an ideal material of the new generation semiconductor today, it has many features such as high saturated electron mobility and wide band. The methods of GaN growth developed rapidly recently. We reviewed recent artiles and then we collect the various of methods about the GaN single crystal growth, after that we compare the difference among these method. This paper mainly talks about three methods of growing GaN single crystal: The Ammonothermal method, the Sodium-flux growth method, and the Halide vapor phase epitaxy (HVPE), and we collect both of the advantages and disadvantages. By putting all characteristics of each methods together we found that combining the HVPE method and Ammonothermal method together can connect the advantages together and avoid some of these disadvantages. We can use the HVPE method to grow the GaN seed and expand the crystal using the Ammonothermal method may be a good choice to grow the GaN single crystal at a low cost. Because if we start with Ammonothermal method, it is easy to form the polycrystalline and if we use the HVPE method to grow large crytal, it is too expensive to do so. Therefore, combining two methods can avoid the disadantages in each other and save the cost when growing.

This review focuses on the impact of numerous conditions on the fluorescence function of silver nanoclusters (AgNCs) as biomarkers. Factors such as particle size, structure and different ligand types are explored. First off, differential stability, sensitivity, cellular uptake, and biodistribution as well as red or blue shifts in absorption and emission wavelengths are caused by varied particle sizes. Furthermore, in the context of detecting microRNA using AgNC-based probes, the presence of a mismatched self-dimer structure is also crucial for achieving a significant red emission. In the final section, the considerable influence of ligands—divided into primary and secondary ligands—on the photoluminescence (PL) characteristics of atomically accurate AgNCs is examined with a focus on Ag29 nanoclusters.

The pollution of plastic materials has seriously affected global environmental problems. Polyolefin materials are widely used as raw materials for plastics. This is due to their practical physical properties and low cost. However, there are major challenges in the disposal of waste polyolefin materials. Recycling and degradation have emerged as the two main approaches for the treatment of plastic waste today. Through a comprehensive literature analysis and review of methods, this paper provides an in-depth study of recycling and biodegradation of polyolefin materials. The study is based on a detailed search of several papers through Google Scholar in order to provide valuable insights into the different methods that are used for the recycling and biodegradation of polyolefins. The review summarizes the most effective technologies for recycling and biodegradation, while highlighting recent advances and future directions in the field. In particular, the research has focused on two main approaches: closed-loop recycling and chemical recovery. The latter technology is aimed at non-polluting biodegradation, which has become an increasingly important topic of interest for the scientific community. Given the urgency of the environmental challenges posed by polyolefins, the development of efficient and sustainable recycling and degradation methods is essential to create a circular economy and ensure a sustainable future.

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.

With the rate of adoption of new energy vehicles, the manufacturing industry of power batteries is swiftly entering a rapid development trajectory. The current construction of new energy vehicles encompasses a variety of different types of batteries. This article offers a summary of the evolution of power batteries, which have grown in tandem with new energy vehicles, oscillating between decline and resurgence in conjunction with industrial advancements, and have continually optimized their performance characteristics up to the present. The main body of this text is dedicated to presenting the working principles and performance features of four primary power batteries: lead-storage batteries, nickel-metal hydride batteries, fuel cells, and lithium-ion batteries, and introduces their current application status and future development prospects. In conclusion, this piece identifies technical obstacles that need to be urgently overcome in the future of new energy vehicle power batteries and anticipates future development trends and emerging battery technologies in current research and development.

The various characteristics of shape memory alloys, such as hyperelasticity, memory alloy effect and so on, make shape memory alloys become a new type of material with broad engineering applications. These components developed based on the characteristics of shape memory alloys are not only used in the aerospace field, but also in various fields such as bridges and railways, and can be used for various purposes such as bridge vibration control and intelligent hybrid control. This article mainly introduces several characteristics of shape memory alloys, and explains the practical application and development prospects of shape memory alloys in the aerospace field. Based on these studies, this article studies the characteristics of shape memory alloys through equation calculus and ANSYS simulation experiments modeling. It can be foreseen in the future that with the development of intelligent control technology, shape memory alloy structures will have a larger operating temperature range, more precise structural control, and will be applied in a wider variety of spacecraft structures.

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.

Due to the burning of fossil energy which is a non-renewable nature resource, it has caused many environmental problems, then the world began to face energy shortage and environmental problems. In order to solve these two problems, people have started to develop new energy sources and vigorously research new methods for energy’s efficient storage and utilization. The Li-ion battery is a research priority because it has great properties such as high specific energy and environmental friendliness, but they still need further performance improvement before it can be put into use. In this paper, the lithium-ion battery’s anode is selected as the research object to investigate the performance of carbon-based nanomaterials, silicon-based nanomaterials, and metal-based nanomaterials, and to study the actual performance and modification methods to analyze the application prospects of the materials. Improving the Li-ion battery cathode material performance can significantly improve the battery’s capacity and performance stability, speed up the process of putting lithium-ion batteries into use, and improve people's ability to store and use energy to cope with the energy crisis.

Because of its high voltage, high specific energy, and other good qualities, lithium-ion batteries have recently become one of the most popular studies. In the context of nanomaterials, this research investigates the function of nanomaterials in the application of lithium-sulfur and lithium-air batteries. In addition to examining the classification, benefits and drawbacks, uses and advances of nanomaterials, this essay also examines the fundamentals of two batteries, as well as the uses of nanomaterials in both types of batteries. The results show that nanomaterials have a very large surface area and a sudden change in material properties because of their arrival at the nanoscale, and have very good mechanical and optical properties, which have a very good contribution to the performance of the batteries. However, it was discovered that nanomaterials in lithium-ion battery applications still have issues, such as high cost and challenging synthesis procedures, through the investigation of several nanomaterials in two batteries. In addition to offering fresh perspectives for society, this study seeks to better understand the economic and safety issues associated with two batteries used in practical production.

Piezoelectric transducers have seen widespread usage in the monitoring of structural health. It has tremendous potential for monitoring the health of infrastructure, especially pavement monitoring. In the present study, the impedance characteristics of a piezoelectric plate embedded in the pavement is utilized to monitor the health status of the pavement. Based on the piezoelectricity principle, a model of an electromechanical piezoelectric plate embedded in pavement is established. The damage of the pavement is considered as the thickness decreasing of the pavement layer. The present proposed model is verified by comparing its degeneration with the exact solution of a single layer model. Numerical results demonstrated that with the deceasing of the thickness of the pavement, which is considered as the deterioration of the pavement, the achievable maximum electromechanical impedance characterization including impedance, admittance and conductance decreased. This demonstrated that the achievable maximum impedance, admittance and conductance of an embedded piezoelectric plate could be used as the indicator of pavement health monitoring. This study primarily presents theoretical underpinnings for pavement monitoring using electromechanical impedance of piezoelectric plates.