The optimized methodology and results of the new characterization in terms of dose and image quality of the X-ray system used in the main pediatric hemodynamics service in Chile are presented. In addition, scattered dose rate values at the operator’s eye level are reported for all acquisition modes available in different thicknesses of absorbent media and angiography. The characterization was performed according to the European DIMOND and SENTINEL protocols adapted to pediatric procedures. The air kerma at the entrance surface (ESAK) was measured and the image quality parameters signal-to-noise ratio (SNR) and a figure of merit (FOM) were calculated. The scattered dose rate was measured in personal dose equivalent units. The ESAK for fluoroscopic modes ranged from 0.2 to 35.6 μGy/image when passing from 4 to 20 cm of polymethyl methacrylate (PMMA). For the cine mode, these values ranged from 2.8 to 160.1 μGy/image. The values of the image quality parameters showed a correct system configuration, although abnormal values were observed in the medium fluoroscopic mode. As for the scattered dose rate at the level of the cardiologist’s eyes, the highest value is PMMA with a thickness of 20 cm, where the cine mode reached 9.41 mSv·h-1. The differences found from previous evaluations can be explained by the deterioration of the system and the change of one of the X-ray tubes.

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.

With the acceleration of economic development and urban construction, urban security accidents have occurred around the world with alarming frequency, causing serious casualties and economic losses. Urban security planning and management as emerging areas of research have drawn widespread attention. For city development plans, urban security planning and management have become one of major topics. This paper first outlines the principles of urban security planning and management, combined with the construction of a digital and intelligent platform for urban emergency management. This research then analyzes the core technology and equipment support system of urban security management and its practical application. It also presents a new model based on urban security planning and management, followed by examples of its application in some mega infrastructure development for security planning and design (for example, Singapore Changi Airport and Shanghai Hongqiao Airport Transportation Hub). Additionally, a blast protection concept of urban security planning and management is provided.

Objective To understand the status quo of problem behavior of children in Henan Province, and to explore the applicability of the Conners Parent Symptom Questionnaire (PSQ) norm test in 3-6 years old children. Methods A total of 775 children aged 3-6 years old in Henan Province were selected to measure their problem behavior by using PSQ. The difference and consistency of the detection rate of Chinese and American norms were analyzed, and the difference between the average score of problem behavior of children in Henan Province and the average score of each factor of the two norms was studied. Results (1) The impulsive-hyperactivity index of boys was significantly higher than that of girls; Children's learning problems show a significant age difference, and the older the children, the higher the score of learning problems; Non-only children show more impulsive-hyperactivity, hyperactivity problems than only children. (2) There are significant differences between the Chinese norm and the American norm in the detection rates of learning problems, impulsive-hyperactivity, anxiety and hyperactivity index. (3) The PSQ scores of children in Henan Province were significantly different from most factors of Chinese and American norm PSQ. Conclusion There are differences in the problem behavior of young children in Henan Province in terms of gender, age, and whether they are only children. The consistency of Chinese and American PSQ norms is poor, and they are no longer applicable to young children in contemporary Henan Province.