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Dynamic evolution of an SVEIR model with variants and non-pharmaceutical interventions for controlling COVID-19

Journal of Biosafety and Biosecurity 2024年第2期6卷 67-75页

作者： Ruiyang Zhou Shaojian Cai Guangmin Chen Senzhong Huang Zhen Jin Zhihang Peng weichuan lin Fengying Wei Kuicheng Zheng School of Mathematics and Statistics Fuzhou UniversityFuzhou 350116FujianChina Fujian Provincial Center for Disease Control and Prevention Fuzhou 350012FujianChina School of Statistics and Data Science ZhiYing Research Center for Health DataNankai UniversityTianjin 300071China Complex Systems Research Center Shanxi UniversityTaiyuan 030006ShanxiChina Department of Biostatistics School of Public HealthNanjing Medical UniversityNanjing 211166JiangsuChina School of Mathematics and Statistics Fujian Normal UniversityFuzhou 350007FujianChina Center for Applied Mathematics of Fujian Province Fuzhou UniversityFuzhou 350116FujianChina Key Laboratory of Operations Research and Control of Universities in Fujian Fuzhou UniversityFuzhou 350116FujianChina Fujian Provincial Key Laboratory of Zoonosis Research Fuzhou 350001FujianChina Teaching Base of the School of Public Health of Fujian Medical University Fuzhou 350001FujianChina

The epidemiological characteristics and distributions of two epidemics in Fujian Province of Southeast China were attributed to the complex interactions among variant,host,and non-pharmaceutical interventions(NPIs).All reported cases in the Putian epidemic(September 8–October 2,2021,Delta variant B.1.617.2)and Fuzhou epidemic(October 22–November 18,2022,Omicron variant BA.5.2)were classified by sex,age group,occupation,and location in this *** surveillance data from the Fujian Provincial Center for Disease Control and Prevention,we established a virus-oriented SVEIR(Susceptible–Vaccinated–Exposed–Infected–Recovered)model to investigate the dynamic evolution features of these two variants and the effects of *** optimal simulations were carried out with variants and scenario *** scenario investigations showed that NPIs significantly reduced the transmission risk and infection scales of COVID-19,and that the Omicron variant was more infectious than the Delta ***,the dynamic investigations revealed the increasing tendencies from Delta to Omicron,such as the basic reproduction number,infection rate,percentage of high-risk cases,and the growth *** tendencies were also identified,such as the average recovery period,the awareness delay,and the percentage of symptomatic *** study highlighted that NPIs played critical roles in successfully containing the two *** interventions are strongly recommended to public health policymakers.

关键词： COVID-19 SVEIR model Transmission dynamics Non-pharmaceutical interventions Delta variant Omicron variant

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Set Sharing Results for Derivatives of Meromorphic Functions

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Journal of Mathematical Research with Applications 2022年第6期42卷 587-598页

作者： Yuxin LI weichuan lin School of Mathematics and Statistics Fujian Normal University

In this paper, we investigate the uniqueness of the derivatives of meromorphic functions sharing two different sets, and obtain the result that if two transcendental meromorphic functions f and g satisfy ■f（k）（S） = ■g（k）（T）, then f（k）= Ag（k）, where S, T are two finite sets and A is a nonzero constant. In particular, k = 0 implies f = Ag.

关键词： meromorphic function shared set uniqueness theorem

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鄂尔多斯盆地西缘低对比度油层流体判识新方法

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测井技术 2024年第1期48卷 117-126页

作者：周妍罗少成牟瑜雷琳琳陈璐林伟川中国石油集团测井有限公司地质研究院陕西西安710077 中国石油天然气集团有限公司测井重点实验室陕西西安710077

随着勘探开发的不断深入,油田勘探开发对象日益复杂化,油水层的低对比度特征愈加突出。受沉积微相、源储配置关系、充注程度等因素影响,低对比度油藏隐蔽性强、油水关系复杂,测井识别评价难度大,解释符合率偏低。因此,亟需建立有效的低... 详细信息

随着勘探开发的不断深入,油田勘探开发对象日益复杂化,油水层的低对比度特征愈加突出。受沉积微相、源储配置关系、充注程度等因素影响,低对比度油藏隐蔽性强、油水关系复杂,测井识别评价难度大,解释符合率偏低。因此,亟需建立有效的低对比度油层流体识别技术,提升测井解释精度。以鄂尔多斯盆地西缘环江西部长8储层为例,从研究岩性、物性、水性、含油性等方面入手,深入剖析研究区低对比度油层成因机理,研究认为地层水矿化度差异、束缚水饱和度高、油藏充注程度低是导致环江油田西部长8储层出现低电阻率、低对比度特征的重要因素。在此基础上建立流体敏感因子识别法;并从测井信号能量构成的角度出发,通过构建流体敏感测井曲线,基于小波变换算法,创新研发了多尺度小波能量谱流体识别技术;针对研究区油藏充注程度低,基于相渗实验创新形成了产水率细分油水同层评价方法。以上3种方法均有效提高了研究区低对比度油层流体性质判识能力,在低对比度油层识别方面应用效果显著。

关键词：低对比度油层流体识别流体敏感因子多尺度小波能量谱产水率

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Assessing the mechanism of citywide test-trace-isolate Zero-COVID policy and exit strategy of COVID-19 pandemic

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Infectious Diseases of Poverty 2022年第5期11卷 97-98页

作者： Pei Yuan Yi Tan Liu Yang Elena Arufo Nicholas H.Ogden Guojing Yang Haixia Lu Zhigui lin weichuan lin Wenjun Ma Meng Fan Kaifa Wang Jianhe Shen Tianmu Chen Huaiping Zhu Laboratory of Mathematical Parallel Systems(LAMPS) Department of Mathematics and StatisticsYork University4700 Keele StreetTorontoON M3J1P3Canada Key Laboratory of Tropical Translational Medicine of Ministry of Education and School of Tropical Medicine and Laboratory Medicine The First Afliated Hospital of Hainan Medical UniversityHainan Medical UniversityHaikouHainanChina 不详

Background:Countries that aimed for eliminating the cases of COVID-19 with test-trace-isolate policy are found to have lower infections,deaths,and better economic performance,compared with those that opted for other mitigation ***,the continuous evolution of new strains has raised the question of whether COVID-19 eradication is still possible given the limited public health response capacity and fatigue of the *** aim to investigate the mechanism of the Zero-COVID policy on outbreak containment,and to explore the possibility of eradication of Omicron transmission using the citywide test-trace-isolate(CTTI)***:We develop a compartmental model incorporating the CTTI Zero-COVID policy to understand how it contributes to the SARS-CoV-2 *** employ our model to mimic the Delta outbreak in Fujian Province,China,from September 10 to October 9,2021,and the Omicron outbreak in Jilin Province,China for the period from March 1 to April 1,*** and sensitivity analyses were conducted using dynamical system and Latin Hypercube Sampling/Partial Rank Correlation Coefcient(PRCC).Results:Calibration results of the model estimate the Fujian Delta outbreak can end in 30(95%confdence interval CI:28–33)days,after 10(95%CI:9–11)rounds of citywide *** emerging Jilin Omicron outbreak may achieve zero COVID cases in 50(95%CI:41–57)days if supported with sufcient public health resources and population compliance,which shows the efectiveness of the CTTI Zero-COVID ***:The CTTI policy shows the capacity for the eradication of the Delta outbreaks and also the Omicron ***,the implementation of radical CTTI is challenging,which requires routine monitoring for early detection,adequate testing capacity,efcient contact tracing,and high isolation compliance,which constrain its benefts in regions with limited ***,these challenges become even more acute in the face of more contagious variant

关键词： COVID-19 Transmission model Zero-COVID policy Citywide testing Test-trace-isolate Exit strategy

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涉及分担三值的非整数级亚纯函数的唯一性定理

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数学物理学报（A辑） 2016年第2期36卷 244-253页

作者：罗杰林伟川福建师范大学数学与计算机科学学院福州350007

该文讨论了亚纯函数的唯一性问题,证明了:如果两个有穷非整数级亚纯函数分担a,b,c IM,且d为它们的广义Picard例外值,则它们必相等.并给出例子表明定理的条件是精确的.

关键词：亚纯函数唯一性非整数级

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具有权弱分担值的差分或微分多项式的亚纯函数的唯一性

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福州大学学报（自然科学版） 2018年第1期46卷 12-19页

作者：林珊华林伟川泉州师范学院数学与计算机科学学院福建泉州362000 福建师范大学数学与计算机科学学院福建福州350007

利用权弱分担的定义以及唯一性理论方法讨论亚纯函数的k阶导数与差分或微分多项式的k阶导数分担值的问题.分析结果表明,当分担"(1,m)"且Θ(∞,f)介于一定范围的情况下,两个函数的k阶导数相等,其中对应不同的m值,n,m需满足不同的不等式.

关键词：差分多项式权弱分担亚纯函数唯一性

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合流超几何函数的零点性质

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数学物理学报（A辑） 2017年第5期37卷 801-807页

作者：林伟川罗旭丹福建师范大学数学系福州350007 Department of Applied Mathematics University of Colorado at Boulder

合流超几何函数在量子力学和统计学中被广泛应用,尤其在数学物理学中的许多问题可以借助此函数的零点位置性质来解决.该文对合流超几何函数_1F_1(α;γ;z):=∞∑n=0((α)_n)/(n!(γ)_n)z^n(α,γ,γ-α■Z≤0)的零点集进行研究,证明了如... 详细信息

合流超几何函数在量子力学和统计学中被广泛应用,尤其在数学物理学中的许多问题可以借助此函数的零点位置性质来解决.该文对合流超几何函数_1F_1(α;γ;z):=∞∑n=0((α)_n)/(n!(γ)_n)z^n(α,γ,γ-α■Z≤0)的零点集进行研究,证明了如果{z_n}_(n=1)~∞是F(α;γ;z)按其模增序排列的零点集,其中重级零点按其重数计算,则存在常数M>0使得|z_n|≥Mn对所有n≥1成立.

关键词：合流超几何函数 Jensen公式整函数零点列

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