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To observe the relations between three important factors resulting in estuarial Hypoxia phenomena of Yangtze River – wind, river flow, and stratification. The purpose of the paper is to analyze the possible reasons why hypoxia occurs in late spring and disappears in October.

To overcome the difficulty in examining the role of physical and biological factors affecting hypoxia based on measurement alone, finite-volume community ocean model (FVCOM) was introduced into the investigation. Observed freshwater flux data from Yangtze River, monthly averaged wind speed data, and other observed data were input into the model; the accuracy of which was validated with various kinds of data. The authors used the trajectories of Lagrangian particles from Yangtze River to study the regions of strong riverine influence under different wind forcing conditions and compared the simulation results with former observations.

Trade wind is a significant factor to influence the forming and receding of hypoxia across the Yangtze River.

Using FVCOM to investigate estuary hypoxia is more economical and effective.

This paper aims to explore the developing trend of higher pedagogy, to promote the research of higher pedagogy to be more canonical and scientific and to improve the higher education theory.

The utility research uses a method of quantitative study, namely “content analysis”, to estimate and analyze the higher education theory literature on ten dimensionalities which include theme, author, abstract, keywords, subject, proposing of the issue, definition of key terms, research methods, conclusion, reference and annotations from 1996 to 2006 in China.

The analysis of the selected 250 academic theses and reports in the field of higher education shows that academic research and theoretical standard have been improved, meanwhile academic criterion have been formed by degrees in higher pedagogy within ten years. At the same time, there are still some problems in the papers and reports the authors have selected such as title, key words, proposing of the issue, researching method and conclusion.

This paper sums up the trend of research on higher education in China for the past ten years, and points out the problems in this trend and then proposes ways to improve the research of higher education in China.

The limited strength of polylactic acid (PLA) hinders its extensive engineering applications. This paper aims to enhance its strength and realize diverse applications.

Here, the continuous fiber reinforced PLA composites are fabricated by a customized fused filament fabrication three-dimensional printer. Uniaxial tensile and three-point flexural tests have been conducted to analyze the reinforcement effect of the proposed composites. To unveil the adhering mechanism of optic fiber (OF) and PLA, post failure analysis including the micro imaging and morphology have been performed. The underlying mechanism is that the axial tensile strength of the OF and the interfacial adhesion between PLA and OF compete to enhance the mechanical properties of the composite.

It is found that 10%–20% enhancement of strength, ductility and toughness due to the incorporation of the continuous OF.

The continuous OFs are put into PLA first time to improve the strength. The fabrication method and process reported here are potentially applied in such engineering applications as aerospace, defense, auto, medicine, etc.

Deployment of deep neural networks on embedded devices is becoming increasingly popular because it can reduce latency and energy consumption for data communication. This paper aims to give out a method for deployment the deep neural networks on a quad-rotor aircraft for further expanding its application scope.

In this paper, a design scheme is proposed to implement the flight mission of the quad-rotor aircraft based on multi-sensor fusion. It integrates attitude acquisition module, global positioning system position acquisition module, optical flow sensor, ultrasonic sensor and Bluetooth communication module, etc. A 32-bit microcontroller is adopted as the main controller for the quad-rotor aircraft. To make the quad-rotor aircraft be more intelligent, the study also proposes a method to deploy the pre-trained deep neural networks model on the microcontroller based on the software packages of the RT-Thread internet of things operating system.

This design provides a simple and efficient design scheme to further integrate artificial intelligence (AI) algorithm for the control system design of quad-rotor aircraft.

This method provides an application example and a design reference for the implementation of AI algorithms on unmanned aerial vehicle or terminal robots.

Students will be able to analyse competitive situations of the focal firm in the platform market, factors that make the focal firm become dominant in the sharing economy through the technology platform and the focal firm’s motives and growth strategies through mergers and acquisitions and overseas expansion, as well as give recommendations on the focal firm’s strategies to move forward to achieve and maintain its competitive position in the platform market.

On 4^th April, 2018, Meituan-Dianping (Meituan), a Chinese group-buying website for consumer products and retail services acquired Mobike, a Chinese dockless bike-sharing platform for US$2.7bn. Mobike had raised several rounds of funding for its large investments and operations in this highly competitive and cash-intensive industry. However, it was still struggling to survive and make a profit in the Chinese and overseas markets. It was believed that the merger between the companies was the only viable alternative. Had Meituan’s Chief Executive Officer made the right decision in acquiring Mobike? After Mobike became an integral part of Meituan, what should be done to turn this technology platform to be profitable in the Chinese and overseas market?

The case is intended for senior undergraduate or graduate-level courses in business schools.

Teaching Notes are available for educators only.

CSS 11: Strategy.

High-performance wrought aluminum alloys, particularly AA6061, are pivotal in industries like automotive and aerospace due to their exceptional strength and good response to heat treatments. Investment casting offers precision manufacturing for these alloys, because casting AA6061 poses challenges like hot cracking and severe shrinkage during solidification. This study aims to address these issues, enabling crack-free investment casting of AA6061, thereby unlocking the full potential of investment casting for high-performance aluminum alloy components.

Nanotechnology is used to enhance the investment casting process, incorporating a small volume fraction of nanoparticles into the alloy melt. The focus is on widely used aluminum alloy 6061, utilizing rapid investment casting (RIC) for both pure AA6061 and nanotechnology-enhanced AA6061. Microstructural characterization involved X-ray diffraction, optical microscopy, scanning electron microscopy, differential scanning calorimetry and energy dispersive X-ray spectroscopy. Mechanical properties were evaluated through microhardness and tensile testing.

The study reveals the success of nanotechnology-enabled investment casting in traditionally challenging wrought aluminum alloys like AA6061. Achieving crack-free casting, enhanced grain morphology and superior mechanical properties, because the nanoparticles control grain sizes and phase growth, overcoming traditional challenges associated with low cooling rates. This breakthrough underscores nanotechnology's transformative impact on the mechanical integrity and casting quality of high-performance aluminum alloys.

This research contributes originality and value by successfully addressing the struggles in investment casting AA6061. The novel nano-treating approach overcomes solidification defects, showcasing the potential of integrating nanotechnology into rapid investment casting. By mitigating challenges in casting high-performance aluminum alloys, this study paves the way for advancements in manufacturing crack-free, high-quality aluminum alloy components, emphasizing nanotechnology's transformative role in precision casting.

Additive manufacturing (AM) can achieve significant weight savings with only minor compromises in strength if high-performance wrought aluminum alloys are used as feedstock. Despite the advantages in strength that aluminum alloys (AA) 6061 offer, they cannot be manufactured via printing because of hot cracking and other solidification problems. The purpose of this study is to achieve high-quality printing of AA6061 with nanotreated wires.

Nanotreating was used to modify the AA6061 alloy composition by adding a small fraction of nanoparticles to enhance the alloy’s manufacturability and resultant properties. Wire arc additive manufacturing (WAAM) was used to print the nanotreated AA6061 wire feedstock. The microstructure of the printed AA6061 was characterized by X-ray crystallography, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy mapping. The microhardness profile, tensile behavior and fracture surface were analyzed.

This work successfully used WAAM to print nanotreated AA 6061 components. The resulting AA6061 parts were crack-free, with exceptional grain morphology and superior mechanical properties. Owing to the excellent size control capabilities of nanoparticles, a homogeneous distribution of small grains was maintained in all deposited layers, even during repeated thermal cycles.

Previous studies have not successfully printed AA6061 using WAAM. Conventional WAAM products exhibit anisotropic mechanical properties. The nanotreated AA6061 was successfully printed to achieve homogeneous microhardness and isotropic tensile properties. The promising results of this study reflect the great potential of nanotech metallurgy as applied to the WAAM process.

The aim of this paper is to better understand the generation and transmission mechanism of the electromagnetic acoustic transducer (EMAT).

A semi-analytical method was used to calculate the Lorentz force. Both the hypothetical magnetic field mirror method and the diffusion equation were adopted to solve the eddy current distribution by variables separation method in time domain. A three-dimension magnetostatic finite element model was used to calculate the static magnetic field and the relative permeability. And an experimental platform with a piezoelectric probe to generate and an EMAT to receive, the ultrasonic wave was set up to verify the distribution of the Lorentz force.

The Lorentz force at different time and in different positions of the steel plate can be easily calculated. The experimental results show a good agreement with the analytical results.

The accurate prediction of the Lorentz force provides an insight into the physical phenomenon of EMAT and a powerful tool to design optimum EMAT.

This study aims to design an optimized algorithm for low-cost pedestrian navigation system (PNS) to correct the heading drift and altitude error, thus achieving high-precise pedestrian location in both two-dimensional (2-D) and three-dimensional (3-D) space.

A novel heading correction algorithm based on smoothing filter at the terminal of zero velocity interval (ZVI) is proposed in the paper. This algorithm adopts the magnetic sensor to calculate all the heading angles in the ZVI and then applies a smoothing filter to obtain the optimal heading angle. Furthermore, heading correction is executed at the terminal moment of ZVI. Meanwhile, an altitude correction algorithm based on step height constraint is proposed to suppress the altitude channel divergence of strapdown inertial navigation system by using the step height as the measurement of the Kalman filter.

The verification experiments were carried out in 2-D and 3-D space to evaluate the performance of the proposed pedestrian navigation algorithm. The results show that the heading drift and altitude error were well corrected. Meanwhile, the path calculated by the novel algorithm has a higher match degree with the reference trajectory, and the positioning errors of the 2-D and 3-D trajectories are both less than 0.5 per cent.

Besides zero velocity update, another two problems, namely, heading drift and altitude error in the PNS, are solved, which ensures the high positioning precision of pedestrian in indoor and outdoor environments.