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The hazards of epoxy resin (EP) are not only reflected in the large amount of smoke and heat released during combustion, but also in the long survival time of bacterial on their surfaces at a time when COVID-19 are prevalent. Therefore, it is crucial to improve the antibacterial properties and fire-resistance of EP. Herein, this paper reports a multifunctional nanoparticle (Cu2O@KF) to overcome this issue. It is found that Cu2O@KF can confer great fire-resistance (LOI = 34.7% and pHRR reduced by 56.3%), antibacterial properties (over 99.99% antibacterial efficiency), and mechanical properties (hardness and Young's modulus increased by 80.0% and 24.0%, respectively) at a low loading level (7 wt%). These ideal characteristics are derived from the multi-synergistic properties among Cu2O and KF. © 2022
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There are differences in the temporal and spatial characteristics of the spread of severe respiratory syndrome (SARS) and new coronavirus pneumonia (COVID-19). In order to explore the difference, this study selected Guangzhou as the research object. Based on the information of confirmed cases of new coronavirus pneumonia (COVID-19) given by the Guangzhou Municipal Health Commission, GIS software was used to analyze the differences in temporal and spatial characteristics of transmission. The study found that: Compared with SARS, COVID-19 spreads more widely and is more contagious. The spread of COVID-19 is characterized by a wide range and dispersion. Compared with SARS, the infection situation of medical staff in the prevention and control of the epidemic has been greatly improved. This study is helpful to grasp the characteristics of the time and space transmission of infectious diseases in metroetpolitan areas and provide effective early warning for emergency decision-making and prevention and control of the epidemic. © 2021 IEEE.
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Financial markets are very sensitive to emerging news related to stock because investors need to continuously monitor financial events when deciding buying and selling stocks. Tracking important events has done mostly using rule-based methods in the past, which is time-consuming in the face of huge online news data. To track this issue, in this paper, a novel document embedding technology based on TF-IDF and BERT incorporating online text cluster algorithm to form an automated event detection system is proposed. Embedding technology is first used to encode text to vectors and then an online text cluster algorithm - SinglePass is implemented to accomplish topic tracking. Experiment results show that the proposed algorithms can effectively detect and track online topics. In addition, both domestic and international events such as the outbreak of novel coronavirus (COVID-19) and Sino-U.S. trade war and their impact on capital market in China are analyzed, which demonstrate the practical and economic value of proposed system. © Springer Nature Switzerland AG 2020.
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Remote sensing course is a general disciplinary required course of human geography and urban-rural planning major. Its class hour is 48, including theoretical classes and experimental classes. Rapid technological developments is remote sensing area demand quick and steady changes in the education programme and its realization, especially in experimental classes. Experimental classes include: introduction to remote sensing software and basic operations, remote sensing data pre-processing (input, output, 2D and 3D terrain display, image cut, image mosaic, and projection transformation), remote sensing image enhancement, remote sensing image transformation, computer aided classification, image interpretation, and remote sensing image terrain analysis. There are two difficulties in the remote sensing experimental classes. First, it cost a lot of time to prepare the remote sensing software and the remote sensing images. Second, some students just want to use the remote sensing as a tool to investigate environment changing, some other students may want to study more remote sensing image processing technologies. A web-based learning environment of remote sensing is developed to facilitate the application of remote sensing experimental teaching. To make the learning more effective, there are eight modules including four optional modules. The Python programming language is chosen to implement the web-based remote sensing learning environment. The web-based learning environment is implemented in a local network server, including the remote sensing data processing algorithms and many satellite image data. Students can easily exercise the remote sensing experimental courses by connecting to the local network server. It is developed mainly for remote sensing experimental course, and also can be adopted by digital image processing or other courses. The feature of web-based learning may be very useful as the online education adopted because of Corona Virus Disease 2019. The results are encouraging and some recommendations will be extracted for the future. © 2020 Authors.
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In recent years, SARS virus, MERS coronavirus, and other global pandemics have occurred frequently. The outbreak of COVID-19 has caused more than 3.7 million infected people and 260000 deaths over 210 countries around the world from December 2019 to May 7, 2020, which has seriously affected the safety of people, the stability of social order, and the development of the economy. Therefore, it is urgent to explore and implement new prevention and control programs for such major pandemics. With the development of robots and artificial intelligence technologies, various intelligent robots for emergency prevention and control in complex conditions have emerged, and they have played paramount roles in disease prevention and control, diagnosis, treatment, and nursing. Based on the problems of insufficient supply of materials and heavy disinfection tasks during the prevention and control of major outbreaks, we study the systematic procedures and applications of medical material handling robots, multi-scene disinfection robots, medical assistant robots, prevention and control robots, and production resumption robots. Moreover, we comparatively analyze the current situation of key technologies of pandemic emergency prevention and control robots, such as environmental perception, autonomous navigation, motion planning, and 5G communication technology. In conclusion, we put forward a technical prospect of intelligent robot systems for emergency prevention and control of major pandemics. © 2020, Science Press. All right reserved.
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Objective: To investigate the epidemiological characteristics for family clusters of COVID-19 in Zhejiang Province. Methods: The data including cases information of asymptomatic infected cases of family clusters of COVID-19 in Zhejiang Province were collected from Public Health Emergencies Reporting System of China Center for Disease Control and Prevention. Calculate the case number of subsequent cases, index cases, asymptomatic infected cases, exposure cases, and then, compute family secondary attack rate (SIR) and serial interval. Results: A total of 389 cases comprised 149 family index cases and 240 subsequent cases. The clinical symptoms between family index cases and subsequent cases (exclude asymptomatic infected cases ) were similar, fever was the most common symptoms in the two groups 115 (77.18%) and 110ï¼48.67%ï¼respectively, the cases with diarrhea symptoms accounted for the least proportion, which were 7 (4.70%) and 6 (2.65%) respectively. The serial interval between the family index cases and the subsequent cases [M (P25, P75)] was 4.00 (2.00, 6.00) days. Family secondary attack rate for subsequent cases was 34.43%, subsequent cases aged between 14 and 60 have the highest SIR (43.42%) compared with other two age groups, the difference was statistically (P<0.001); the family SIR of the spouses of the family index cases is 68.57%, and are higher than that of parents (29.03%), children (25.00%) and other family members (24.21%), the difference was also statistically (P<0.001). Conclusion: 2019 novel coronavirus has shorter serial interval and higher family SIR, the SIR of spouses is higher than other family members.