By using two PM2.5 automatic monitors,the protective effects of five common masks against PM2.5 were synchronously tested under actual ambient air conditions for a whole day. The results showed that not all masks had ...By using two PM2.5 automatic monitors,the protective effects of five common masks against PM2.5 were synchronously tested under actual ambient air conditions for a whole day. The results showed that not all masks had protective effects on PM2.5,and the protective effects of masks N95 and N90,which were designed specially for dust-proof,were superior among the five tested masks.展开更多
In order to solve the problem of experimental research on the penetration process of projectile into anchored rock mass, we derived the essential similarity conditions for the physical simulation experi- ment accordin...In order to solve the problem of experimental research on the penetration process of projectile into anchored rock mass, we derived the essential similarity conditions for the physical simulation experi- ment according to the similarity theory, carried out the experiment on the penetration process of a kind of penetrating bomb into the anchored rock mass of type III, and compared the experimental results with the values computed by the professional Young's empirical formula. The test results show that the phys- ical simulation experiment can represent the actual penetration process of projectile into anchored rock mass. The research method proposed in this paper provides technical support for the experimental research on the design and reconstruction of underground protection works.展开更多
The paper intfoduces a PC-DSP based real-time digital simulator which is portable in size and aimed at the closed-loop testing of various types of protective relays for their design and application. The simulator can ...The paper intfoduces a PC-DSP based real-time digital simulator which is portable in size and aimed at the closed-loop testing of various types of protective relays for their design and application. The simulator can be widely used in not only concerning utilities but also manufacturers and research / certification institutes because of its many functions. The hardware architecture and software implementation of the simulator are described. The main features and functions of the simulator are also展开更多
基金Supported by the Monitoring Scientific Research Foundation of Jiangsu Province,China in 2013(1321)
文摘By using two PM2.5 automatic monitors,the protective effects of five common masks against PM2.5 were synchronously tested under actual ambient air conditions for a whole day. The results showed that not all masks had protective effects on PM2.5,and the protective effects of masks N95 and N90,which were designed specially for dust-proof,were superior among the five tested masks.
文摘In order to solve the problem of experimental research on the penetration process of projectile into anchored rock mass, we derived the essential similarity conditions for the physical simulation experi- ment according to the similarity theory, carried out the experiment on the penetration process of a kind of penetrating bomb into the anchored rock mass of type III, and compared the experimental results with the values computed by the professional Young's empirical formula. The test results show that the phys- ical simulation experiment can represent the actual penetration process of projectile into anchored rock mass. The research method proposed in this paper provides technical support for the experimental research on the design and reconstruction of underground protection works.
文摘The paper intfoduces a PC-DSP based real-time digital simulator which is portable in size and aimed at the closed-loop testing of various types of protective relays for their design and application. The simulator can be widely used in not only concerning utilities but also manufacturers and research / certification institutes because of its many functions. The hardware architecture and software implementation of the simulator are described. The main features and functions of the simulator are also