Fire warning is vital to human life,economy and ecology.However,the development of effective warning systems faces great challenges of fast response,adjustable threshold and remote detecting.Here,we propose an intelli...Fire warning is vital to human life,economy and ecology.However,the development of effective warning systems faces great challenges of fast response,adjustable threshold and remote detecting.Here,we propose an intelligent self-powered remote IoT fire warning system,by employing single-walled carbon nanotube/titanium carbide thermoelectric composite films.The flexible films,prepared by a convenient solution mixing,display p-type characteristic with excellent high-temperature stability,flame retardancy and TE(power factor of 239.7±15.8μW m^(-1) K^(-2))performances.The comprehensive morphology and structural analyses shed light on the underlying mechanisms.And the assembled TE devices(TEDs)exhibit fast fire warning with adjustable warning threshold voltages(1–10 mV).Excitingly,an ultrafast fire warning response time of~0.1 s at 1 mV threshold voltage is achieved,rivaling many state-of-the-art systems.Furthermore,TE fire warning systems reveal outstanding stability after 50 repeated cycles and desired durability even undergoing 180 days of air exposure.Finally,a TED-based wireless intelligent fire warning system has been developed by coupling an amplifier,analogto-digital converter and Bluetooth module.By combining TE characteristics,high-temperature stability and flame retardancy with wireless IoT signal transmission,TE-based hybrid system developed here is promising for next-generation self-powered remote IoT fire warning applications.展开更多
The effect of tourism on water environments has received a high degree of interest in the study of eco-tourism.Based on the analysis of the relationship between tourist activities and the water environment in the Liup...The effect of tourism on water environments has received a high degree of interest in the study of eco-tourism.Based on the analysis of the relationship between tourist activities and the water environment in the Liupan Mountain eco-tourism zone,the case study area,a Water Environment of Tourism Area Model(WETAM) is built to simulate the temporal and spatial changes in water quality and the response saturation thresholds under four sewage treatment scenarios.The results imply the following:(1) WETAM performs well in modeling a water environment to represent the dynamic process of water quality change in response to tourist activities.(2) Under four sewage treatment scenarios(fundamental,low,medium,and high),the threshold shows an obvious uptrend.(3) The response threshold of water quality with respect to the interference of tourist activities fluctuates seasonally due to changes in tourist density.(4) The thresholds differ significantly among five tourism functional areas.According to the response saturation threshold of the water environment,effective control based on the scale and intensity of tourist activities is important for a successful transformation of this tourism destination's development strategies.Therefore,the integrated management of water pollution in tourism areas plays a crucial role in sustainable tourism development.展开更多
The China Infectious Disease Automated-alert and Response System（CIDARS） was successfully implemented and became operational nationwide in 2008. The CIDARS plays an important role in and has been integrated into the...The China Infectious Disease Automated-alert and Response System（CIDARS） was successfully implemented and became operational nationwide in 2008. The CIDARS plays an important role in and has been integrated into the routine outbreak monitoring efforts of the Center for Disease Control（CDC） at all levels in China. In the CIDARS, thresholds are determined using the ？Mean＋2SD？ in the early stage which have limitations. This study compared the performance of optimized thresholds defined using the ？Mean ＋2SD？ method to the performance of 5 novel algorithms to select optimal ？Outbreak Gold Standard（OGS）？ and corresponding thresholds for outbreak detection. Data for infectious disease were organized by calendar week and year. The ？Mean＋2 SD？, C1, C2, moving average（MA）, seasonal model（SM）, and cumulative sum（CUSUM） algorithms were applied. Outbreak signals for the predicted value（Px） were calculated using a percentile-based moving window. When the outbreak signals generated by an algorithm were in line with a Px generated outbreak signal for each week, this Px was then defined as the optimized threshold for that algorithm. In this study, six infectious diseases were selected and classified into TYPE A（chickenpox and mumps）, TYPE B（influenza and rubella） and TYPE C [hand foot and mouth disease（HFMD） and scarlet fever]. Optimized thresholds for chickenpox（P_（55））, mumps（P_（50））, influenza（P_（40）, P_（55）, and P_（75））, rubella（P_（45） and P_（75））, HFMD（P_（65） and P_（70））, and scarlet fever（P_（75） and P_（80）） were identified. The C1, C2, CUSUM, SM, and MA algorithms were appropriate for TYPE A. All 6 algorithms were appropriate for TYPE B. C1 and CUSUM algorithms were appropriate for TYPE C. It is critical to incorporate more flexible algorithms as OGS into the CIDRAS and to identify the proper OGS and corresponding recommended optimized threshold by different infectious disease types.展开更多
The stinging response thresholds of individual European and Africanized worker honeybees (Apis mellifera L.) were analyzed. Workers of each genotype performing defense (guard and soldier bees) and non-defense (nest an...The stinging response thresholds of individual European and Africanized worker honeybees (Apis mellifera L.) were analyzed. Workers of each genotype performing defense (guard and soldier bees) and non-defense (nest and forager bees) associated tasks were collected and exposed to an electric stimulus of 0.5 mA, and the time they took to sting a leather substrate was recorded. Africanized bees had significant lower thresholds of response than European bees. Guards and soldiers were faster to sting than nest and forager bees for the Africanized genotype, whereas for the European genotype, guards stung significantly faster than bees of the other three task groups. This is the first study that shows that individual bees specialized in two defensive tasks also have a lower response threshold for stinging. Our results fit a model of division of labor based on differences in response thresholds to stimuli among workers of different genotypes and task groups.展开更多
Chronic non-communicable diseases have become a significant threat to the health of middle-aged and older adults in urban areas.The allocation of health resources in urban communities is associated with the prevalence...Chronic non-communicable diseases have become a significant threat to the health of middle-aged and older adults in urban areas.The allocation of health resources in urban communities is associated with the prevalence of chronic diseases.This study conducts an empirical analysis using threshold regression methods based on data from the China Health and Retirement Longitudinal Study(CHARLS).It explores the nonlinear impact of community health resource allocation on chronic disease management among middle-aged and older adults across different age groups.The goal is to allocate health resources scientifically based on the health and activity needs of specific age groups.The results reveal staged differences across distinct age intervals.Specifically,the allocation of community health resources has a negative impact on the management of chronic diseases of respondents under 58 years old,an insignificant impact for those aged between 58 and 73 years,and a significant positive impact for those aged above 73 years old.The threshold effect of age is closely related to the health resource preference and activity pattern of different age groups.The alignment between health resource supply and demand within these groups determines their effectiveness in improving health outcomes.These findings could help optimize the spatial allocation of health resources,enhance planning standards,and address existing disparities across communities,thereby providing an evidence-based solution for urban planning decisions.展开更多
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2022A1515110296,2022A1515110432)the Shenzhen Science and Technology Program(No.20231120171032001,20231122125728001).
文摘Fire warning is vital to human life,economy and ecology.However,the development of effective warning systems faces great challenges of fast response,adjustable threshold and remote detecting.Here,we propose an intelligent self-powered remote IoT fire warning system,by employing single-walled carbon nanotube/titanium carbide thermoelectric composite films.The flexible films,prepared by a convenient solution mixing,display p-type characteristic with excellent high-temperature stability,flame retardancy and TE(power factor of 239.7±15.8μW m^(-1) K^(-2))performances.The comprehensive morphology and structural analyses shed light on the underlying mechanisms.And the assembled TE devices(TEDs)exhibit fast fire warning with adjustable warning threshold voltages(1–10 mV).Excitingly,an ultrafast fire warning response time of~0.1 s at 1 mV threshold voltage is achieved,rivaling many state-of-the-art systems.Furthermore,TE fire warning systems reveal outstanding stability after 50 repeated cycles and desired durability even undergoing 180 days of air exposure.Finally,a TED-based wireless intelligent fire warning system has been developed by coupling an amplifier,analogto-digital converter and Bluetooth module.By combining TE characteristics,high-temperature stability and flame retardancy with wireless IoT signal transmission,TE-based hybrid system developed here is promising for next-generation self-powered remote IoT fire warning applications.
基金supported by the National Natural Science Foundation of China(Project No.40971299)
文摘The effect of tourism on water environments has received a high degree of interest in the study of eco-tourism.Based on the analysis of the relationship between tourist activities and the water environment in the Liupan Mountain eco-tourism zone,the case study area,a Water Environment of Tourism Area Model(WETAM) is built to simulate the temporal and spatial changes in water quality and the response saturation thresholds under four sewage treatment scenarios.The results imply the following:(1) WETAM performs well in modeling a water environment to represent the dynamic process of water quality change in response to tourist activities.(2) Under four sewage treatment scenarios(fundamental,low,medium,and high),the threshold shows an obvious uptrend.(3) The response threshold of water quality with respect to the interference of tourist activities fluctuates seasonally due to changes in tourist density.(4) The thresholds differ significantly among five tourism functional areas.According to the response saturation threshold of the water environment,effective control based on the scale and intensity of tourist activities is important for a successful transformation of this tourism destination's development strategies.Therefore,the integrated management of water pollution in tourism areas plays a crucial role in sustainable tourism development.
基金supported by the Key Laboratory of Public Health Safety of the Ministry of Education,Fudan University,China(No.GW2015-1)
文摘The China Infectious Disease Automated-alert and Response System（CIDARS） was successfully implemented and became operational nationwide in 2008. The CIDARS plays an important role in and has been integrated into the routine outbreak monitoring efforts of the Center for Disease Control（CDC） at all levels in China. In the CIDARS, thresholds are determined using the ？Mean＋2SD？ in the early stage which have limitations. This study compared the performance of optimized thresholds defined using the ？Mean ＋2SD？ method to the performance of 5 novel algorithms to select optimal ？Outbreak Gold Standard（OGS）？ and corresponding thresholds for outbreak detection. Data for infectious disease were organized by calendar week and year. The ？Mean＋2 SD？, C1, C2, moving average（MA）, seasonal model（SM）, and cumulative sum（CUSUM） algorithms were applied. Outbreak signals for the predicted value（Px） were calculated using a percentile-based moving window. When the outbreak signals generated by an algorithm were in line with a Px generated outbreak signal for each week, this Px was then defined as the optimized threshold for that algorithm. In this study, six infectious diseases were selected and classified into TYPE A（chickenpox and mumps）, TYPE B（influenza and rubella） and TYPE C [hand foot and mouth disease（HFMD） and scarlet fever]. Optimized thresholds for chickenpox（P_（55））, mumps（P_（50））, influenza（P_（40）, P_（55）, and P_（75））, rubella（P_（45） and P_（75））, HFMD（P_（65） and P_（70））, and scarlet fever（P_（75） and P_（80）） were identified. The C1, C2, CUSUM, SM, and MA algorithms were appropriate for TYPE A. All 6 algorithms were appropriate for TYPE B. C1 and CUSUM algorithms were appropriate for TYPE C. It is critical to incorporate more flexible algorithms as OGS into the CIDRAS and to identify the proper OGS and corresponding recommended optimized threshold by different infectious disease types.
文摘The stinging response thresholds of individual European and Africanized worker honeybees (Apis mellifera L.) were analyzed. Workers of each genotype performing defense (guard and soldier bees) and non-defense (nest and forager bees) associated tasks were collected and exposed to an electric stimulus of 0.5 mA, and the time they took to sting a leather substrate was recorded. Africanized bees had significant lower thresholds of response than European bees. Guards and soldiers were faster to sting than nest and forager bees for the Africanized genotype, whereas for the European genotype, guards stung significantly faster than bees of the other three task groups. This is the first study that shows that individual bees specialized in two defensive tasks also have a lower response threshold for stinging. Our results fit a model of division of labor based on differences in response thresholds to stimuli among workers of different genotypes and task groups.
文摘Chronic non-communicable diseases have become a significant threat to the health of middle-aged and older adults in urban areas.The allocation of health resources in urban communities is associated with the prevalence of chronic diseases.This study conducts an empirical analysis using threshold regression methods based on data from the China Health and Retirement Longitudinal Study(CHARLS).It explores the nonlinear impact of community health resource allocation on chronic disease management among middle-aged and older adults across different age groups.The goal is to allocate health resources scientifically based on the health and activity needs of specific age groups.The results reveal staged differences across distinct age intervals.Specifically,the allocation of community health resources has a negative impact on the management of chronic diseases of respondents under 58 years old,an insignificant impact for those aged between 58 and 73 years,and a significant positive impact for those aged above 73 years old.The threshold effect of age is closely related to the health resource preference and activity pattern of different age groups.The alignment between health resource supply and demand within these groups determines their effectiveness in improving health outcomes.These findings could help optimize the spatial allocation of health resources,enhance planning standards,and address existing disparities across communities,thereby providing an evidence-based solution for urban planning decisions.
