3D printing technology is an emerging technology in recent years, which can achieve rapid display of objects through the feeding method. It has been widely used in various industrial sectors. Higher vocational and technical colleges are one of the important ways to cultivate higher technical personnel from various industries. They must keep up with the pace of educational reform and introduce 3D printing technology into corresponding classrooms. Under the guidance of the course "Fundamentals of Mechanical Design", this article utilizes 3D printing technology to apply common PRO/E to products, achieving various motion mechanisms, making the originally monotonous classroom teaching lively and allowing students to immediately showcase their creativity.

[Objective]In order to explore the sustainable food security level in the Yangtze River Economic Belt, ensure food security and sustainable development of agricultural modernization, it is necessary to establish a scientific food security evaluation system to safeguard local food security.[Methods]This paper takes the food system of the Yangtze River Economic Belt in China as the research object, based on the food security research results at home and abroad, based on sustainable development thinking, combined with a new perspective of dynamic equilibrium research: Beginning with food normalcy, a comprehensive analysis of food production, food economy, social development, ecological security, and technical support for sustainable development is presented using the entropy-weighted TOPSIS model to build a food security evaluation system for sustainable development. [Conclusion]After systematic analysis, it is concluded that (1) the average value of food security score of the Yangtze River Economic Belt from 2008 to 2021 is 0.429, and the overall food in the Yangtze River Economic Belt is in general security level (0.400 ≤ Q1 ≤ 0.600), and the overall situation of food security is not optimistic, (2) from the segmentation of the Yangtze River Economic Belt, the high and low level of food security are divided into sections: midstream > downstream > upstream, and each province and city is slowly rising to different degrees. In this way, we propose general countermeasures to ensure local food security from the perspective of sustainable development.

Since my country entered the era of Internet economy, the scale of the software industry is gradually expanding, and programming language, as an important tool and idea for software development, is a necessary skill for every development practitioner. Among them, C language, as the basic language of computer software programming, is also an important basic course for cultivating students’ computer application ability in science and engineering majors in colleges and universities. This paper mainly studies the teaching reform of C language programming courses and proposes corresponding optimization measures, so as to lay a solid foundation for the continuous improvement of students’ learning quality of C language courses and the continuous strengthening of programming ability.

Nanomaterials stand as transformative elements across diverse domains, ranging from biotechnology, aircraft, aviation, and space exploration to medicine, health, environmental preservation, resources, energy, and aerospace. This issue, comprising nine original research articles and two insightful reviews, we embark on a journey to unravel the multifaceted uses of nanomaterials, with a special emphasis on their contributions to environmental protection and medicine. Delving into the unique traits of various nanomaterials, our aim is to provide readers with a comprehensive understanding that transcends conventional boundaries, fostering a deeper appreciation for the impact of nanomaterials.

A theory of many-body wave scattering is developed under the assumption a << d << λ, where a is the characteristic size of the small body, d is the distance between neighboring bodies and λ is the wave-length in the medium in which the bodies are embedded. The multiple scattering is essential under these assumptions. The author’s theory is used for creating materials with a desired refraction coefficient. This theory can be used in practice. A recipe for creating materials with a desired refraction coefficient is formulated. Materials with a desired radiation pattern, for example, wave-focusing materials, can be created.