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学者姓名：张楠
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摘要 ：
To quantify the risk of the transmission of respiratory infections in indoor environments, we systematically assessed exposure to talking-and breathing-generated respiratory droplets in a generic indoor environment using computational fluid dynamic (CFD) simulations. The flow field in the indoor environment was obtained with SST k-omega model and Lagrangian method was used to predict droplet trajectories, where droplet evaporation was considered. Droplets can be categorized into small droplets (initial size <= 30 mu m or <= 10 mu m as droplet nuclei), medium droplets (30-80 mu m) and large droplets (>100 mu m) according to the exposure characteristics. Droplets up to 100 mu m, particular the small ones, can contribute to both short-range and long-range airborne routes. For the face-to-face talking scenario, the intake fraction and deposition fractions of droplets on the face and facial mucosa of the susceptible were up to 4.96%, 2.14%, and 0.12%, respectively, indicating inhalation is the dominant route. The exposure risk from a talking infector decreases monotonically with the interpersonal dis-tance, while that of nasal-breathing generated droplets maintains a relatively stable level within 1.0 m. Keeping an angle of 15 degrees or above with the expiratory flow is efficient to reduce intake fractions to <0.37% for small droplets. Adjusting the orientation from face-to-face to face-to-back can reduce exposure to small droplets by approximately 88.0% during talking and 66.2% during breathing. A higher ventilation rate can reduce the risk of exposure to small droplets but may increase the risk of transmission via medium droplets by enhancing their evaporation rate. This study would serve as a fundamental research for epidemiologist, healthcare workers and the public in the purpose of infection control.
关键词 ：
Relative position Relative position Interpersonal distance Interpersonal distance Close contact Close contact Respiratory droplets Respiratory droplets COVID-19 COVID-19 Airborne route Airborne route
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| GB/T 7714 | Wei, Jianjian , Wang, Lei , Jin, Tao et al. Effects of occupant behavior and ventilation on exposure to respiratory droplets in the indoor environment [J]. | BUILDING AND ENVIRONMENT , 2023 , 229 . |
| MLA | Wei, Jianjian et al. "Effects of occupant behavior and ventilation on exposure to respiratory droplets in the indoor environment" . | BUILDING AND ENVIRONMENT 229 (2023) . |
| APA | Wei, Jianjian , Wang, Lei , Jin, Tao , Li, Yuguo , Zhang, Nan . Effects of occupant behavior and ventilation on exposure to respiratory droplets in the indoor environment . | BUILDING AND ENVIRONMENT , 2023 , 229 . |
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摘要 ：
Debate and scientific inquiries regarding airborne transmission of respiratory infections such as COVID-19 and influenza continue. Health authorities including the WHO and the US CDC have recognized the airborne transmission of COVID-19 in specific settings, although the ventilation requirements remain to be determined. In this work we consider the long-range airborne transmission as an extended short-range airborne route, which reconciles the link between short- and long-range airborne routes. The effective short-range distance is defined as the distance in short range at which long-range route has the same volumetric exposure value as that due to short-range route. Our data show that a decrease in ventilation rate or room volume per person, or an increase in the ratio of the number of infected to susceptible people reduces the effective short-range distance. In a normal breathing scenario with one out of five people infected and a room volume of 12 m3 per person to ensure an effective short-range distance of 1.5 m, a ventilation rate of 10 L/s per person is needed for a duration of 2 h. Our results suggest that effective environmental prevention strategies for respiratory infections require appropriate increases in the ventilation rate while maintaining a sufficiently low occupancy. Practical implications: Demonstration of the long-range airborne route as an extended short-range airborne route suggests the significant role played by building ventilation in respiratory infection exposure. The reconciliation of short- and long-range airborne transmission suggests that the commonly observed dominance of close-contact transmission is a probable evidence of short-range airborne transmission, following a separate earlier study that revealed the relative insignificance of large droplet transmission in comparison with the short-range airborneroute. Existing ventilation standards do not account for respiratory infection control, and this study presents a possible approach to account for infection under new ventilation standards.
关键词 ：
Airborne transmission Airborne transmission COVID-19 COVID-19 Crowding Crowding Indoor environment Indoor environment Ventilation rate Ventilation rate
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| GB/T 7714 | Chen, Wenzhao , Qian, Hua , Zhang, Nan et al. Extended short-range airborne transmission of respiratory infections [J]. | JOURNAL OF HAZARDOUS MATERIALS , 2022 , 422 . |
| MLA | Chen, Wenzhao et al. "Extended short-range airborne transmission of respiratory infections" . | JOURNAL OF HAZARDOUS MATERIALS 422 (2022) . |
| APA | Chen, Wenzhao , Qian, Hua , Zhang, Nan , Liu, Fan , Liu, Li , Li, Yuguo . Extended short-range airborne transmission of respiratory infections . | JOURNAL OF HAZARDOUS MATERIALS , 2022 , 422 . |
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摘要 ：
通过构建数学模型,定量研究了1个3人家庭环境中飞沫传播、接触传播和气溶胶传播在COVID-19传播中的作用。研究表明,飞沫传播和接触传播在COVID-19传播中起着最重要的作用。和患者交流时保持1.5～2 m的空间距离对控制飞沫传播至关重要,洗手和保护环境表面清洁是控制接触传播的最有效手段。虽然通过气溶胶途径传播风险相对较小,但当患者呼出飞沫中病原体浓度较高时(患者可能为超级感染者),在家庭环境中24 h暴露下,气溶胶传播风险依然可以高达26%。
关键词 ：
接触传播 接触传播 数学模型 数学模型 新型冠状病毒 新型冠状病毒 气溶胶传播 气溶胶传播 相对重要性 相对重要性 飞沫传播 飞沫传播
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| GB/T 7714 | 雷浩 , 肖胜蓝 , 张楠 et al. 新型冠状病毒在家庭环境中的主要传播途径 [J]. | 科技导报 , 2021 , 39 (09) : 78-86 . |
| MLA | 雷浩 et al. "新型冠状病毒在家庭环境中的主要传播途径" . | 科技导报 39 . 09 (2021) : 78-86 . |
| APA | 雷浩 , 肖胜蓝 , 张楠 , 魏健健 , 金滔 . 新型冠状病毒在家庭环境中的主要传播途径 . | 科技导报 , 2021 , 39 (09) , 78-86 . |
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摘要 ：
COVID-19 threatens the world. Social distancing is a significant factor in determining the spread of this disease, and social distancing is strongly affected by the local travel behaviour of people in large cities. In this study, we analysed the changes in the local travel behaviour of various population groups in Hong Kong, between 1 January and 31 March 2020, by using second-by-second smartcard data obtained from the Mass Transit Railway Corporation (MTRC) system. Due to the pandemic, local travel volume decreased by 43%, 49% and 59% during weekdays, Saturdays and Sundays, respectively. The local travel volumes of adults, children, students and senior citizens decreased by 42%, 86%, 73% and 48%, respectively. The local travel behaviour changes for adults and seniors between non-pandemic and pandemic times were greater than those between weekdays and weekends. The opposite was true for children and students. During the pandemic, the daily commute flow decreased by 42%. Local trips to shopping areas, amusement areas and borders decreased by 42%, 81% and 99%, respectively. The effective reproduction number (R t ) of COVID-19 had the strongest association with daily population use of the MTR 7-8 days earlier.
关键词 ：
COVID-19 COVID-19 Effective reproduction number Effective reproduction number Human behaviour Human behaviour Local travel behaviour Local travel behaviour Public transport Public transport Subway Subway
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| GB/T 7714 | Zhang Nan , Jia Wei , Wang Peihua et al. Changes in local travel behaviour before and during the COVID-19 pandemic in Hong Kong. [J]. | Cities , 2021 , 112 : 103139 . |
| MLA | Zhang Nan et al. "Changes in local travel behaviour before and during the COVID-19 pandemic in Hong Kong." . | Cities 112 (2021) : 103139 . |
| APA | Zhang Nan , Jia Wei , Wang Peihua , Dung Chung-Hin , Zhao Pengcheng , Leung Kathy et al. Changes in local travel behaviour before and during the COVID-19 pandemic in Hong Kong. . | Cities , 2021 , 112 , 103139 . |
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摘要 ：
The association between the footwear microclimate and microbial community on the foot plantar skin was investigated by experiments with three participants. Novel methods were developed for measuring in-shoe temperature and humidity at five footwear regions, as well as the overall ventilation rate inside the footwear. Three types of footwear were tested including casual shoes, running shoes, and perforated shoes for pairwise comparison of footwear microclimate and corresponding microbial community on the skin. The major findings are as follows: (1) footwear types make a significant difference to in-shoe temperature at the instep region with the casual shoes sustaining the warmest of all types; (2) significant differences were observed in local internal absolute humidity between footwear types, with the casual shoes sustaining the highest level of humidity at most regions; (3) the perforated shoes provided the highest ventilation rate, followed by running and casual shoes, and the faster the gait, the larger the discrepancy in ventilation rate between footwear types; (4) the casual shoes seemed to provide the most favorable internal environment for bacterial growth at the distal plantar skin; and (5) the bacterial growth at the distal plantar skin showed a positive linear correlation with the in-shoe temperature and absolute humidity, and a negative linear correlation with the ventilation rate. The ventilation rate seemed to be a more reliable indicator of the bacterial growth. Above all, we can conclude that footwear microclimate varies in footwear types, which makes contributions to the bacterial growth on the foot plantar skin.
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| GB/T 7714 | Miao, Te , Wang, Peihua , Zhang, Nan et al. Footwear microclimate and its effects on the microbial community of the plantar skin [J]. | SCIENTIFIC REPORTS , 2021 , 11 (1) . |
| MLA | Miao, Te et al. "Footwear microclimate and its effects on the microbial community of the plantar skin" . | SCIENTIFIC REPORTS 11 . 1 (2021) . |
| APA | Miao, Te , Wang, Peihua , Zhang, Nan , Li, Yuguo . Footwear microclimate and its effects on the microbial community of the plantar skin . | SCIENTIFIC REPORTS , 2021 , 11 (1) . |
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摘要 ：
The photocatalytic activity of polymeric carbon nitride (g-C3N4) strongly depends on its electronic structure which is highly sensitive to the preparation methods. To design the photocatalysts with efficient charge separation and transfer property, here we report a new ethylenediamine (EDA) induced gas-solid grafting method which enables the asymmetric modification of g-C3N4 featuring the aromatization at the terminal of melon motifs. The obtained terminal-aromatized g-C3N4 (Ar-C3N4) exhibits an improved visible-light-driven photocatalytic activity in versatile two-electron reduction reactions, outperforming the pristine g-C3N4 by 15.4 and 6.6 folds respectively in hydrogen evolution and hydrogen peroxide production. Theoretical and experimental results demonstrate the intensified asymmetry of p-electron distribution in the resulting material, which provides significantly improved driving force to guide the efficient separation of photogenerated e-h pairs and enhance the charge carrier mobility compared to its symmetric counterpart.
关键词 ：
Asymmetric structure Asymmetric structure Photocatalytic reductions Photocatalytic reductions Gas-solid grafting reaction Gas-solid grafting reaction Terminal blocking Terminal blocking Aromatization Aromatization
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| GB/T 7714 | Luo, Wei , Li, Yongli , Wang, Jinshu et al. Asymmetric structure engineering of polymeric carbon nitride for visible-light-driven reduction reactions [J]. | NANO ENERGY , 2021 , 87 . |
| MLA | Luo, Wei et al. "Asymmetric structure engineering of polymeric carbon nitride for visible-light-driven reduction reactions" . | NANO ENERGY 87 (2021) . |
| APA | Luo, Wei , Li, Yongli , Wang, Jinshu , Liu, Jingchao , Zhang, Nan , Zhao, Mengdi et al. Asymmetric structure engineering of polymeric carbon nitride for visible-light-driven reduction reactions . | NANO ENERGY , 2021 , 87 . |
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摘要 ：
Phthalates are typical air pollutants in vehicular environment since numerous synthetic materials that might contain phthalates are widely used to fabricate vehicle interiors (e.g., seat cushions, floor mats and dashboards). Hitherto, the importance of phthalate pollution in vehicular environment is not well-recognized because people spend only a small portion (around 8%) of their time in vehicles. In this study, the mass fractions of six phthalates in nine materials commonly used in Chinese vehicles (floor mats and seat cushions) were measured. Two phthalates, di-n-butyl phthalate (DnBP) and di-2-ethylhexyl phthalate (DEHP), were identified in most materials (the other phthalates were not detected). The emission characteristics of DnBP and DEHP from these materials were further investigated. The measured emission parameters were used as input for a mass-transfer model to estimate DnBP and DEHP concentrations in cabin air. Finally, the ratios between human exposures (via inhalation and dermal absorption from the gas phase) in vehicular environment and the total exposures in typical indoor environments (e.g., residences and offices) were estimated to be up to 110% and 20% for DnBP and DEHP, respectively. Based on these results, the vehicular environment might be a considerable site for human exposure to airborne phthalates.
关键词 ：
emission emission indoor air quality indoor air quality phthalates phthalates mass transfer mass transfer vehicular environment vehicular environment exposure assessment exposure assessment
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| GB/T 7714 | Bu, Zhongming , Hu, Maochao , Yuan, Fangzhou et al. Phthalates in Chinese vehicular environments: Source emissions, concentrations, and human exposure [J]. | INDOOR AIR , 2021 , 31 (6) : 2118-2129 . |
| MLA | Bu, Zhongming et al. "Phthalates in Chinese vehicular environments: Source emissions, concentrations, and human exposure" . | INDOOR AIR 31 . 6 (2021) : 2118-2129 . |
| APA | Bu, Zhongming , Hu, Maochao , Yuan, Fangzhou , Xu, Yousheng , Dong, Cong , Zhang, Nan et al. Phthalates in Chinese vehicular environments: Source emissions, concentrations, and human exposure . | INDOOR AIR , 2021 , 31 (6) , 2118-2129 . |
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摘要 ：
By the end of February 2021, COVID-19 had spread to over 230 countries, with more than 100 million confirmed cases and 2.5 million deaths. To control infection spread with the least disruption to economic and societal activities, it is crucial to implement the various interventions effectively. In this study, we developed an agentbased SEIR model, using real demographic and geographic data from Hong Kong, to analyse the efficiency of various intervention strategies in preventing infection by the SARS-CoV-2 virus. Close contact route including short-range airborne is considered as the main transmission routes for COVID-19 spread. Contact tracing is not that useful if all other interventions have been fully deployed. The number of infected individuals could be halved if people reduced their close contact rate by 25%. For reducing transmission, students should be prioritized for vaccination rather than retired older people and preschool aged children. Home isolation, and taking the nucleic acid test (NAT) as soon as possible after symptom onset, are much more effective interventions than wearing masks in public places. Temperature screening in public places only disrupted the infection spread by a small amount when other interventions have been fully implemented. Our results may be useful for other highly populated cities, when choosing their intervention strategies to prevent outbreaks of COVID-19 and similar diseases.
关键词 ：
COVID-19 COVID-19 SEIR model SEIR model Temperature screening Temperature screening Vaccine Vaccine Mask Mask Close contact Close contact
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| GB/T 7714 | Zhang, Nan , Chan, Pak-To Jack , Jia, Wei et al. Analysis of efficacy of intervention strategies for COVID-19 transmission: A case study of Hong Kong [J]. | ENVIRONMENT INTERNATIONAL , 2021 , 156 . |
| MLA | Zhang, Nan et al. "Analysis of efficacy of intervention strategies for COVID-19 transmission: A case study of Hong Kong" . | ENVIRONMENT INTERNATIONAL 156 (2021) . |
| APA | Zhang, Nan , Chan, Pak-To Jack , Jia, Wei , Dung, Chung-Hin , Zhao, Pengcheng , Lei, Hao et al. Analysis of efficacy of intervention strategies for COVID-19 transmission: A case study of Hong Kong . | ENVIRONMENT INTERNATIONAL , 2021 , 156 . |
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摘要 ：
The effect of hydrodynamic force on the seismic response of structure in water cannot be ignored. Various methods have been developed to describe the effect of incompressible water, but the relative performance of some practical simplified methods is largely unknown. In this paper a comprehensive comparison of three representative simplified methods for assessing cylindrical hydrodynamic force is presented. Relative errors of structural elastic peak responses are constructed to measure the accuracy of the simplified method. The errors are tested on 154 circular cylinders subjected to 100 ground motions. The errors were first obtained by averaging the results of ground motions. Then the comparison between methods and the influence of parameters were studied based on the mean errors. Furthermore, by analyzing the statistical characteristic values of the errors, the kernel density estimation method was adopted to obtain the probability density of the errors. Finally, the probabilities of cylindrical cases and methods were investigated. The results show that if the added mass of hydrodynamic force depends on more structural parameters, the accuracy of the method may higher. The rigid-structure method has the highest accuracy and the most complicated expression. The accuracy and complexity of the method based on approximation of fundamental frequency are moderate. The Morison method has the simplest form and the maximum error. The results indicate that the added mass should relate to several structural parameters, ignoring the change of the added mass along the height will bring error to method and assuming the structure to be rigid is an effective way to simplify the analytical hydrodynamics.
关键词 ：
Probability density Probability density Seismic response Seismic response Simplified method Simplified method Water-cylinder interaction Water-cylinder interaction
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| GB/T 7714 | Guo, Jie , Zhao, Mi , Wang, Piguang et al. Comparative assessment of simplified methods for hydrodynamic force on cylinder under earthquakes [J]. | OCEAN ENGINEERING , 2021 , 234 . |
| MLA | Guo, Jie et al. "Comparative assessment of simplified methods for hydrodynamic force on cylinder under earthquakes" . | OCEAN ENGINEERING 234 (2021) . |
| APA | Guo, Jie , Zhao, Mi , Wang, Piguang , Zhang, Nan . Comparative assessment of simplified methods for hydrodynamic force on cylinder under earthquakes . | OCEAN ENGINEERING , 2021 , 234 . |
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摘要 ：
Infectious disease-causing pathogens can be transmitted via contact with contaminated environmental surfaces (i.e., fomite transmission). However, the physical mechanism of fomite transmission remains unclear because of a lack of suitable surrogate tracers. In this study, the non-toxic, non-human-origin and gram-positive bacterium Lactobacillus delbrueckii subsp. Bulgaricus was selected as a tracer, and its applicability for studying bacterial contamination spread on environmental surfaces was investigated in an office setting. After bacterial introduction by a designated carrier, surface contamination levels indicated by the L. bulgaricus proline iminopeptidase (pepIP) gene copy numbers were quantified using an optimized qPCR assay. This qPCR assay exhibited a high sensitivity (55 copies per reaction mixture and 1585 copies per surface sample), a wide dynamic range (7 orders of magnitude) and a high specificity for pepIP gene in environmental surface samples. Three independent, natural and unsupervised field experiments involving human participants confirmed the applicability of L. bulgaricus as a tracer in field studies and the pepIP gene as a unique marker of externally introduced contamination. Experimentally, contamination was distributed nearly equally over public surfaces, the carrier's seat location and the other seat locations in the office setting. An analysis by seat location revealed that the contamination level was attenuated as the physical distance from the carrier's seat location increased. Volunteers' faces were ubiquitously contaminated, suggesting a potentially high risk of fomite exposure via mucous membranes. In conclusion, L. bulgaricus can feasibly be used as a tracer organism in future large-scale field studies of bacterial contamination spread on environmental surfaces. © 2021 Elsevier Ltd
关键词 ：
Genes Genes Contamination Contamination Optimization Optimization Bacteria Bacteria Polymerase chain reaction Polymerase chain reaction Location Location
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| GB/T 7714 | Wang, Peihua , Zhang, Nan , Lee, Patrick K.H. et al. Quantification of Lactobacillus delbrueckii subsp. Bulgaricus and its applicability as a tracer for studying contamination spread on environmental surfaces [J]. | Building and Environment , 2021 , 197 . |
| MLA | Wang, Peihua et al. "Quantification of Lactobacillus delbrueckii subsp. Bulgaricus and its applicability as a tracer for studying contamination spread on environmental surfaces" . | Building and Environment 197 (2021) . |
| APA | Wang, Peihua , Zhang, Nan , Lee, Patrick K.H. , Li, Yuguo . Quantification of Lactobacillus delbrueckii subsp. Bulgaricus and its applicability as a tracer for studying contamination spread on environmental surfaces . | Building and Environment , 2021 , 197 . |
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