As of May 2024,the main strains of COVID-19 caused hundreds of millions of infection cases and millions of deaths worldwide.In this study,we consider the COVID-19 epidemics with the main strains in the Chinese mainlan...As of May 2024,the main strains of COVID-19 caused hundreds of millions of infection cases and millions of deaths worldwide.In this study,we consider the COVID-19 epidemics with the main strains in the Chinese mainland.We study complex interactions among hosts,non-pharmaceutical interventions,and vaccinations for the main strains by a differential equation model called SVEIR.The disease transmission model incorporates two strains and protection awareness of the susceptible population.Results of this study show that the protection awareness plays a crucial role against infection of the population,and that the vaccines are effective against the circulation of the earlier strains,but ineffective for emerging strains.By using the next generation matrix method,the basic reproduction number of the SVEIR model is firstly obtained.Our analysis by Hurwitz criterion and LaSalle's invariance principle shows that the disease free-equilibrium point is locally and globally asymptotically stable when the threshold value is below one.The existences of endemic equilibrium points are also established,and the global asymptotic stabilities are analyzed using the Lyapunov function method.Further,the SVEIR model is confirmed to satisfy the principle of competitive exclusion,of which the strain with the larger value of the basic reproduction number is dominant.Numerically,the surveillance data with the Omicron strain and the XBB strain are split by the cubic spline interpolation method.The fitting curves against the surveillance data are plotted using the least-squares method from MATLAB.The results indicate that the XBB strain dominates in this study.Moreover,a global sensitivity analysis of the key parameters is performed by using of PRCC.The numerical simulations imply that combination control strategy positively impacts on the infection scale than what separate control strategy does,and that the earlier time producing protection awareness for the public creates less infection scale,further that the increment of protection awareness also reduces the infection scale.Therefore,the policymakers of the local government are suggested to concern the changes of protection awareness of the public.展开更多
Background:HepatitisCvirus(HCV)is a bloodborne virus that causes both acute and chronic hepatitis with the severity from a mild illness to liver airrhosis and cancer.As one of the major infectious diseases in China,th...Background:HepatitisCvirus(HCV)is a bloodborne virus that causes both acute and chronic hepatitis with the severity from a mild illness to liver airrhosis and cancer.As one of the major infectious diseases in China,the monthly surveillance data from the Fujian Provincial Center for Disease Control and Prevention shows the increasing tendency from 2004 to 2011,the stable tendency from 2012 to 2016,and the dedining tendency from 2017 to 2022.The 2004-2022HCV infectiontendency of Fujian Province is affected by nation-wide main control measures of Chinese government,because no control measures for HCV are modified from 2020 to 2022 during the prevalence of COVID-19 in Fujian Province.Methods:The SEACTR(the susceptible,the exposed,the acutely infected,the chronically infected,the treated,the recovered)models with protection awareness are proposed.The next generation matrix method is used to compute basic reproduction number of toy model and dynamic analysis method is used to produce stochastic reproduction number of modified model.The least squares method and toy model are used to perform the optimal fitting against the monthly surveillance data.The positive preserving truncated Euler-Maruyama method is applied in modified model for the positivity of numerical simulations.Results:The optimal fitting is performed using the monthly surveillancedata provided by the Fujian Provincial Center for Disease Control and Prevention from 2004 to 2022.The sensitivities of protection efficiency and conversion rate to basic reproduction number and stochastic reproduction number are analyzed.The reproduction numbers and HCV infec-tion scale with measures(single-measure,double-measure,triple-measure,and none-measure)are compared using toy model and modified model.The impacts of protection efficiency and conversion rate on exposed population,acutely infected population,chronically infectedpopulation,and treated population are analyzed.The tendency predictions for infected population and treated population in Fujian Province from 2023 to 2035 are conducted Conclusions:The HCV infection scale mainly depends on both protection efficiency and conversion rate,in which protection efficiency is the most important contributor.The reproduction numbers show the declining tendendes by phases,which indicate that the prevention and control of HCV in Fujian Province has achieved a remarkable achievement.The 2023-2035tendency predictions of HCV infection scale in Fujian Province grow slowly due to approximately 19-109 monthly infections.The overal HCV growth tendency of Fujian Province is consistent with the nation-wide elimination objective.展开更多
With the increasing popularity of ecological civilization and sustainable development,enterprises should consider environmental protection measures in their operations in addition to pursue their economic interests.Th...With the increasing popularity of ecological civilization and sustainable development,enterprises should consider environmental protection measures in their operations in addition to pursue their economic interests.This paper establsihes a closed-loop supply chain network model composed of multiple suppliers,manufacturers,retailers,recyclers,and demand markets—regarding their dual goals of the profit maximization and the minimization of carbon emissions.The conditions necessary for establishing overall equilibrium and an equilibrium model of the entire closed-loop supply chain network are determined by applying variational inequality and dual theory.A modified projection contraction algorithm is used to design a model-solving program.Finally,using numerical examples,the paper conducts a comparative static analysis on important parameters such as the weight coefficients of environmental protection objectives and consumers'awareness of low-carbon environmental protection and attains some beneficial enlightenment on management.The results indicate that when the environmental protection objectives of a certain type of enterprise increases,both the economic benefits and environmental protection performance will improve;when the environmental protection objectives of all enterprises increases simultaneously,environmental protection performance improves significantly,but the changes in economic benefits of different enterprises are inconsistent and profit coordination is more complex.Although consumers’awareness of low-carbon preference could improve environmental performance,it reduces the overall profits of network members and the entire closed-loop supply chain network as a whole.The above conclusions can be used as a reference for the government in designing low-carbon environmental protection policy and in closed-loop supply chain research.展开更多
In the rapid industrialization and urbanization of China,the damage of ecological environment hinders the people's pursuit of good environmental quality.As a technical means of ecological environment protection,th...In the rapid industrialization and urbanization of China,the damage of ecological environment hinders the people's pursuit of good environmental quality.As a technical means of ecological environment protection,the assessment of ecological environment damage has been attached great importance by all walks of life.However,there are still some problems in the current practice of environmental damage assessment.Therefore,based on the understanding of ecological environment damage assessment and related concepts,this study systematically studies the theory of ecological environment damage assessment.Based on the research,it can be seen that the assessment of ecological environment damage is the inevitable product of social and economic development and the promotion of environmental protection awareness,and ecological environment damage belongs to the subordinate concept of"environmental damage".The assessment of ecological environment damage includes the assessment of ecological damage and environmental damage,paying attention to the interests of human society and the unclaimed pure environment and pure ecological damage.The assessment of ecological environmental damage determines the goal and direction for the construction of environmental damage compensation system.This study enriches the theory of environmental damage assessment and provides theoretical reference and method basis for environmental damage assessment.展开更多
The Sagalla caecilian(Boulengerula niedeni)is an endangered amphibian endemic to Sagalla Hill in the Taita Hills.This burrowing worm-like species prefers soft soil with high moisture and organic matter.The major threa...The Sagalla caecilian(Boulengerula niedeni)is an endangered amphibian endemic to Sagalla Hill in the Taita Hills.This burrowing worm-like species prefers soft soil with high moisture and organic matter.The major threats to the Sagalla caecilian are soil erosion caused by steep slopes,bare ground and water siphoning/soil hardening from exotic eucalyptus trees.The purpose of this study was to get a better understanding of the local people's attitude towards this species and how they can contribute to its continued conservation through restoration of its remaining habitat.In this study,it was found that 96%of Sagalla people are aware of the species,its habits and its association with soils high in organic matter.It was also found that 96%of Sagalla people use organic manure from cow dung in their farms.Habitat restoration through planting of indigenous plants was found to be ongoing,especially on compounds of public institutions as well as on private lands.Although drought was found to be a challenge for seedlings development especially on the low elevation sites,destruction by livestock especially during the dry season is also a major threat.In this study,it was recommended that any future habitat restoration initiative should include strong chain-link fencing to protect the seedlings from livestock activity.Recognizing that the preferred habitats for the species are in the valleys,systematic planting of keystone plant species such as fig trees(Ficus)creates the best microhabitats.These are better than general woodlots of indigenous trees.展开更多
ZHOU Youhong works to inform students about environmental protection. Enthusiastic about her work, she spreads knowledge to element college and secondary school students. She said only when she began studying in unive...ZHOU Youhong works to inform students about environmental protection. Enthusiastic about her work, she spreads knowledge to element college and secondary school students. She said only when she began studying in university did she realize the harm of industrial pollution. She said she hopes through her efforts she can help the younger generation realize the value of environmental protection.展开更多
基金supported by the Natural Science Foundation of Fujian Province of China(2021J01621)Special Projects of the Central Government Guiding Local Science and Technology Development(2021L3018)+1 种基金Consultancy Project by the Chinese Academy of Engineering(2022-JB-06,2023-JB-12)Project for epidemiological characteristics analysis and clustering epidemics analysis of COVID-19 in Jinzhou City(JZ2024B066).
文摘As of May 2024,the main strains of COVID-19 caused hundreds of millions of infection cases and millions of deaths worldwide.In this study,we consider the COVID-19 epidemics with the main strains in the Chinese mainland.We study complex interactions among hosts,non-pharmaceutical interventions,and vaccinations for the main strains by a differential equation model called SVEIR.The disease transmission model incorporates two strains and protection awareness of the susceptible population.Results of this study show that the protection awareness plays a crucial role against infection of the population,and that the vaccines are effective against the circulation of the earlier strains,but ineffective for emerging strains.By using the next generation matrix method,the basic reproduction number of the SVEIR model is firstly obtained.Our analysis by Hurwitz criterion and LaSalle's invariance principle shows that the disease free-equilibrium point is locally and globally asymptotically stable when the threshold value is below one.The existences of endemic equilibrium points are also established,and the global asymptotic stabilities are analyzed using the Lyapunov function method.Further,the SVEIR model is confirmed to satisfy the principle of competitive exclusion,of which the strain with the larger value of the basic reproduction number is dominant.Numerically,the surveillance data with the Omicron strain and the XBB strain are split by the cubic spline interpolation method.The fitting curves against the surveillance data are plotted using the least-squares method from MATLAB.The results indicate that the XBB strain dominates in this study.Moreover,a global sensitivity analysis of the key parameters is performed by using of PRCC.The numerical simulations imply that combination control strategy positively impacts on the infection scale than what separate control strategy does,and that the earlier time producing protection awareness for the public creates less infection scale,further that the increment of protection awareness also reduces the infection scale.Therefore,the policymakers of the local government are suggested to concern the changes of protection awareness of the public.
基金supported by Natural Science Foundation of Fujian Province of China(2021J01621)supported by National Natural Science Foundation of China(12231012)+3 种基金supported by Royal Society of Edinburgh(RSE1832)Engineering and Physical Sciences Research Council(EP/W522521/1)supported by The Major Health Research Project of Fujian Province(2021ZD01001)Fujian Research and Training Grants for Young and Middle-aged Leaders in Healthcare(202501140018).
文摘Background:HepatitisCvirus(HCV)is a bloodborne virus that causes both acute and chronic hepatitis with the severity from a mild illness to liver airrhosis and cancer.As one of the major infectious diseases in China,the monthly surveillance data from the Fujian Provincial Center for Disease Control and Prevention shows the increasing tendency from 2004 to 2011,the stable tendency from 2012 to 2016,and the dedining tendency from 2017 to 2022.The 2004-2022HCV infectiontendency of Fujian Province is affected by nation-wide main control measures of Chinese government,because no control measures for HCV are modified from 2020 to 2022 during the prevalence of COVID-19 in Fujian Province.Methods:The SEACTR(the susceptible,the exposed,the acutely infected,the chronically infected,the treated,the recovered)models with protection awareness are proposed.The next generation matrix method is used to compute basic reproduction number of toy model and dynamic analysis method is used to produce stochastic reproduction number of modified model.The least squares method and toy model are used to perform the optimal fitting against the monthly surveillance data.The positive preserving truncated Euler-Maruyama method is applied in modified model for the positivity of numerical simulations.Results:The optimal fitting is performed using the monthly surveillancedata provided by the Fujian Provincial Center for Disease Control and Prevention from 2004 to 2022.The sensitivities of protection efficiency and conversion rate to basic reproduction number and stochastic reproduction number are analyzed.The reproduction numbers and HCV infec-tion scale with measures(single-measure,double-measure,triple-measure,and none-measure)are compared using toy model and modified model.The impacts of protection efficiency and conversion rate on exposed population,acutely infected population,chronically infectedpopulation,and treated population are analyzed.The tendency predictions for infected population and treated population in Fujian Province from 2023 to 2035 are conducted Conclusions:The HCV infection scale mainly depends on both protection efficiency and conversion rate,in which protection efficiency is the most important contributor.The reproduction numbers show the declining tendendes by phases,which indicate that the prevention and control of HCV in Fujian Province has achieved a remarkable achievement.The 2023-2035tendency predictions of HCV infection scale in Fujian Province grow slowly due to approximately 19-109 monthly infections.The overal HCV growth tendency of Fujian Province is consistent with the nation-wide elimination objective.
基金supported by Humanity and Social Science Foundation of Ministry of Education of China[Grant number 17YJA630130].
文摘With the increasing popularity of ecological civilization and sustainable development,enterprises should consider environmental protection measures in their operations in addition to pursue their economic interests.This paper establsihes a closed-loop supply chain network model composed of multiple suppliers,manufacturers,retailers,recyclers,and demand markets—regarding their dual goals of the profit maximization and the minimization of carbon emissions.The conditions necessary for establishing overall equilibrium and an equilibrium model of the entire closed-loop supply chain network are determined by applying variational inequality and dual theory.A modified projection contraction algorithm is used to design a model-solving program.Finally,using numerical examples,the paper conducts a comparative static analysis on important parameters such as the weight coefficients of environmental protection objectives and consumers'awareness of low-carbon environmental protection and attains some beneficial enlightenment on management.The results indicate that when the environmental protection objectives of a certain type of enterprise increases,both the economic benefits and environmental protection performance will improve;when the environmental protection objectives of all enterprises increases simultaneously,environmental protection performance improves significantly,but the changes in economic benefits of different enterprises are inconsistent and profit coordination is more complex.Although consumers’awareness of low-carbon preference could improve environmental performance,it reduces the overall profits of network members and the entire closed-loop supply chain network as a whole.The above conclusions can be used as a reference for the government in designing low-carbon environmental protection policy and in closed-loop supply chain research.
基金Supported by Guizhou Science and Technology Planning Project (QKHPTRC[2018]5404)Construction of Environmental Inspection and Testing Service Platform (QKYKZHZ[2017]02)
文摘In the rapid industrialization and urbanization of China,the damage of ecological environment hinders the people's pursuit of good environmental quality.As a technical means of ecological environment protection,the assessment of ecological environment damage has been attached great importance by all walks of life.However,there are still some problems in the current practice of environmental damage assessment.Therefore,based on the understanding of ecological environment damage assessment and related concepts,this study systematically studies the theory of ecological environment damage assessment.Based on the research,it can be seen that the assessment of ecological environment damage is the inevitable product of social and economic development and the promotion of environmental protection awareness,and ecological environment damage belongs to the subordinate concept of"environmental damage".The assessment of ecological environment damage includes the assessment of ecological damage and environmental damage,paying attention to the interests of human society and the unclaimed pure environment and pure ecological damage.The assessment of ecological environmental damage determines the goal and direction for the construction of environmental damage compensation system.This study enriches the theory of environmental damage assessment and provides theoretical reference and method basis for environmental damage assessment.
基金Foundation items:This study was supported by the Mohamed bin Zayed Species Conservation Fund(MBZ)on the education(project number 11251778)and awareness work by US Fish&Wildlife Service(USFWS)project award number F11AP00359 on habitat restoration work
文摘The Sagalla caecilian(Boulengerula niedeni)is an endangered amphibian endemic to Sagalla Hill in the Taita Hills.This burrowing worm-like species prefers soft soil with high moisture and organic matter.The major threats to the Sagalla caecilian are soil erosion caused by steep slopes,bare ground and water siphoning/soil hardening from exotic eucalyptus trees.The purpose of this study was to get a better understanding of the local people's attitude towards this species and how they can contribute to its continued conservation through restoration of its remaining habitat.In this study,it was found that 96%of Sagalla people are aware of the species,its habits and its association with soils high in organic matter.It was also found that 96%of Sagalla people use organic manure from cow dung in their farms.Habitat restoration through planting of indigenous plants was found to be ongoing,especially on compounds of public institutions as well as on private lands.Although drought was found to be a challenge for seedlings development especially on the low elevation sites,destruction by livestock especially during the dry season is also a major threat.In this study,it was recommended that any future habitat restoration initiative should include strong chain-link fencing to protect the seedlings from livestock activity.Recognizing that the preferred habitats for the species are in the valleys,systematic planting of keystone plant species such as fig trees(Ficus)creates the best microhabitats.These are better than general woodlots of indigenous trees.
文摘ZHOU Youhong works to inform students about environmental protection. Enthusiastic about her work, she spreads knowledge to element college and secondary school students. She said only when she began studying in university did she realize the harm of industrial pollution. She said she hopes through her efforts she can help the younger generation realize the value of environmental protection.
