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Underwater multicell single-layer thin metal plate corner reflectors can’t form a relatively stable TS in a large space because of its strong frequency characteristics. To solve the problem, the paper designs the underwater multicell cavity corner reflectors. Then using FEM coupled DBEM solver to simulated its scattering acoustic field in incident wave frequence varies from 5.0 kHz to 15.0 kHz. The results show that the underwater multicell cavity corner reflectors has weak frequency characteristics, obvious decoupling effect and strong scattering ability. Underwater multicell cavity corner reflectors can maintain stable target strength in a large space, and has better reflection ability, so it is an ideal underwater acoustic reflection device.

After over 60 years of development, the space propulsion field in China has made tremendous progress in terms of technology system and product pedigree, and has supported major engineering applications including manned spaceflight, applied satellites, and deep space exploration. However, considering the requirements of future major aerospace missions in China, the technical level of current space propulsion systems is still insufficient, and it is urgent to plan directions for the innovative development and breakthroughs of the field. This study reviews the development status of the space propulsion systems from the aspects of electric, chemical, nuclear, and new-concept space propulsion, and analyzes the requirements of future applications. Specifically, high-performance, low-cost space propulsion systems are required to support the networking of low-Earth-orbit (LEO) small satellites; high-thrust, reusable low-temperature chemical propulsion technologies are required for new space-transportation systems; and multi-type, long-life space propulsion technologies are required for deep-space applications. The results demonstrate that the space propulsion field in China still faces multiple challenges. First, the system reliability and lifespan require further improvement. Second, the space propulsion systems of China still lag behind the advanced international level in terms of product maturity of some technologies. Third, this field typically has a high product cost. Fourth, there are few types of optional technologies, and the research progress of key technologies is lagging. Therefore, we propose the following suggestions: (1) optimizing technology options through top-level planning, (2) improving the development mechanism of the field by emphasizing basic research, and (3) clarifying and promoting scientific research and development in key technological directions, thereby achieving in-orbit applications of the propulsion systems for LEO small satellites, Earth–Moon space transfer, and deep space exploration (including manned spaceflight).

Intelligent control systems can effectively assist in the construction and management of laboratory animal facilities, improving operational efficiency, ensuring the reliability of animal experimental results, and significantly saving human resources. The intelligent control system for laboratory animal facilities at Shenzhen Institute for Drug Control was completed in April 2021. It includes an intelligent management platform and an information management system for animal laboratories. The intelligent management platform regulates room environment parameters such as temperature, humidity, and pressure through building equipment management system, controlling devices such as the Venturi valve, electric air valve, electric water valve, and steam humidification valve. At the same time, various environmental parameters are monitored online through the environmental monitoring system. The laboratory’s intelligence is further enhanced by systems such as automatic lighting control, full HD video monitoring, automatic access control and door system, independent ventilation and feeding, automatic cleaning, automatic exhaust gas treatment, centralized gas supply, and real-time instrument parameter monitoring. The information management system for animal laboratories integrates inspection, instrument and equipment, personnel, documents, standard substances, reagents, inspection standards, books, records, scientific research management, relevant applications, quality management, and query statistics. For animal experimentation, a management module has been developed to achieve a comprehensive digitization of animal management. Furthermore, real-time collection and recording of data such as balance calibration, sample quality, and animal weight are facilitated through electronic experimental recording. In summary, the Animal Laboratory of Shenzhen Institute for Drug Control has extensively utilized intelligent systems to achieve real-time online control and monitoring, improve efficiency, ensure high-quality facility operation, and meet standard requirements. Smooth execution of all inspection and research activities has been achieved over the past three years. This paper provides insights into the construction, management, and operation of laboratory animal facilities at Shenzhen Institute for Drug Control, offering guidance for the implementation of intelligent control in similar facilities across China.