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Global Stability of a Mumps Transmission Model with Quarantine Measure

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Acta Mathematicae Applicatae Sinica 2021年第4期37卷 665-672页

作者： Yu-zhen BAI Xiao-jing WANG Song-bai guo School of Science Beijing University of Civil Engineering and ArchitectureBeijing102616China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing100190China

In this paper,a model of mumps transmission with quarantine measure is proposed and then the control reproduction number Rc of the model is *** model admits a unique endemic equilibrium P*if and only if Rc>1,while the disease-free equilibrium P0 always *** using the technique of constructing Lyapunov functions and the generalized Lyapunov-LaSalle theorem,we first show that the equilibrium P0 is globally asymptotically stable(GAS)if Rc≤1;second,we prove that the equilibrium P*is GAS if Rc>*** results reveal that mumps can be eliminated from the community for Rc≤1 and it will be persistent for Rc>1,and quarantine measure can also effectively control the mumps transmission.

关键词： mumps transmission model control reproduction number quarantine measure global stability

N-Oxide heterocycles and imidazoles replacing ring D of calanolides against Mycobacterium tuberculosis

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Chinese Chemical Letters 2016年第1期27卷 51-54页

作者： Zi-Jie Liu Xiao-Yong guo Gang Liu Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College Tsinghua-Peking Center for Life Sciences and Department of Pharmacology and Pharmaceutical Sciences School of Medicine Tsinghua University

We have explored the chemistry of N-oxide heterocycles and imidazoles replacing ring D of the natural product（＋）-calanolide A, and have synthesized 12 new analogues, two of which were active against both R Mtb and ... 详细信息

关键词： Mycobacterium tuberculosis (+)-Calanolide A N-Oxide heterocycle Benzoimidazole Bioreductive drug

关键信息基础设施软件供应链风险分析及应对方法研究

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信息安全研究 2024年第9期10卷 833-839页

作者：李祉岐郭晨萌汤文玉杨思敏王雪岩国网思极网安科技(北京)有限公司北京102200

关键信息基础设施中系统的安全保护至关重要,软件供应链风险分析在其中不可或缺.近年来供应链攻击事件迅速增长,形势严峻.以软件供应链威胁的主要诱因,如“外部”的软件成分、人员、支撑工具等要素的潜在问题分析为出发点,结合对国内外... 详细信息

关键信息基础设施中系统的安全保护至关重要,软件供应链风险分析在其中不可或缺.近年来供应链攻击事件迅速增长,形势严峻.以软件供应链威胁的主要诱因,如“外部”的软件成分、人员、支撑工具等要素的潜在问题分析为出发点,结合对国内外政策和技术的现状研究,提出了针对电力行业系统的软件供应链安全保障框架,涵盖了外部组件治理、供应商管理、研运设施加固、软件物料清单应用机制4方面15组安全方法,并可持续扩展,旨在为电力行业重要信息系统的软件供应链安全防护提供参考.

关键词：关键信息基础设施系统安全软件供应链安全保障框架电力行业

Computing R_(0) of dynamic models by a definition-based method

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Infectious Disease Modelling 2022年第2期7卷 196-210页

作者： Xiaohao guo Yichao guo Zeyu Zhao Shiting Yang Yanhua Su Benhua Zhao Tianmu Chen State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics School of Public HealthXiamen UniversityXiamen City361102Fujian ProvincePeople's Republic of China Universite de Montpellier CIRADIntertrypIESUniversite de Montpellier-CNRSMontpellierFrance

Objectives:Computing the basic reproduction number(R0)in deterministic dynamical models is a hot topic and is frequently demanded by researchers in public *** nextgeneration methods(NGM)are widely used for such computation,however,the results of NGM are usually not to be the true R0 but only a threshold quantity with little *** this paper,a definition-based method(DBM)is proposed to solve such a ***:Start with the definition of R0,consider different states that one infected individual may develop into,and take expectations.A comparison with NGM has *** verification is performed using parameters fitted by data of COVID-19 in Hunan ***:DBM and NGM give identical expressions for single-host models with single-group and interactive Rij of single-host models with multi-groups,while difference arises for models partitioned into *** verification showed the consistencies and differences between DBM and NGM,which supports the conclusion that R0 derived by DBM with true epidemiological interpretations are ***:DBM is more suitable for single-host models,especially for models partitioned into ***,for multi-host dynamic models where the true R0 is failed to define,we may turn to the NGM for the threshold R0.

关键词： Definition-based method Dynamics model Basic reproduction number Next-generation method

Embodied exergy-based assessment of energy and resource consumption of buildings

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Frontiers of Earth Science 2014年第1期8卷 150-162页

作者： Jing MENG Zhi LI Jiashuo LI Ling SHAO Mengyao HAN Shan guo College of Urban and Environmental Sciences Peking University Beijing 100871 China State Key Laboratory for Turbulence and Complex Systems College of Engineering Peking University Beijing 100871 China

As an effective approach to achieve a more unified and scientific assessment, embodied exergy-based analysis is devised to assess the energy and resource consumption of buildings. A systematic accounting of the landmark buildings in E-town, Beijing is performed, on the basis of raw project data in the bill of Quantities （BOQ） and the most recent embodied exergy intensities for the Chinese economy in 2007 with 135 industrial sectors. The embodied exergy of the engineering structure of the case buildings is quantified as 4.95E ＋ 14 J, corresponding to an intensity of 8.25E ＋ 09 J/m2 floor area. Total exergy of 51.9% and 28.8% are embodied in the steel and concrete inputs, respectively, due to the fact that the case buildings are structured of reinforced-concrete. The fossil fuel source （coal, crude oil, and natural gas） is predominant among four categories of natural resources （fossil fuel, biological, mineral, and environmental）, accounting for 89.9% of the embodied exergy, with coal as the dominant energy resource （75.5%）. The material accounts for 89.5% of the embodied exergy, in contrast to 9.0%, 1.4%, and 0.1% for manpower, energy, and equipment respectively. This result indicates that great attention should be given to the use of various materials vs. their value of their contribution

关键词： energy resources exergy analysis greenbuilding ecological assessment

Simulating potential outbreaks of Delta and Omicron variants based on contact-tracing data:A modelling study in Fujian Province,China

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Infectious Disease Modelling 2023年第1期8卷 270-281页

作者： Yichao guo Wenjing Ye Zeyu Zhao Xiaohao guo Wentao Song Yanhua Su Benhua Zhao Jianming Ou Yanqin Deng Tianmu Chen State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics School of Public HealthXiamen UniversityXiamen City361102Fujian ProvincePR China Fujian Provincial Center for Disease Control and Prevention Fujian ProvincePR China

Although studies have compared the relative severity of Omicron and Delta variants by assessing the relative risks,there are still gaps in the knowledge of the potential COVID-19 burden these variations may *** the contact patterns in Fujian Province,China,have not been *** identified 8969 transmission pairs in Fujian,China,by analyzing a contact-tracing database that recorded a SARS-CoV-2 outbreak in September *** estimated the waning vaccine effectiveness against Delta variant infection,contact patterns,and epidemiology distributions,then simulated potential outbreaks of Delta and Omicron variants using a multi-group mathematical *** instance,in the contact setting without stringent lockdowns,we estimated that in a potential Omicron wave,only 4.7%of infections would occur in Fujian Province among individuals aged>60 *** comparison,58.75%of the death toll would occur in unvaccinated individuals aged>60 *** with no strict lockdowns,combining school or factory closure alone reduced cumulative deaths of Delta and Omicron by 28.5%and 6.1%,*** conclusion,this study validates the need for continuous mass immunization,especially among elderly aged over 60 years *** it confirms that the effect of lockdowns alone in reducing infections or deaths is ***,these measurements will still contribute to lowering peak daily incidence and delaying the epidemic,easing the healthcare system's burden.

关键词： Contact tracing Vaccine effectiveness Variant of concern Mathematical model COVID-19

Spectral absorption control of femtosecond laser-treated metals and application in solar-thermal devices

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Light(Science & Applications) 2020年第1期9卷 1851-1859页

作者： Sohail A.Jalil Bo Lai Mohamed ElKabbash Jihua Zhang Erik M.Garcell Subhash Singh Chunlei guo The Institute of Optics University of RochesterRochesterNY 14627USA These authors contributed equally:Sohail A.JalilBo Lai

Direct femtosecond(fs)laser processing is a maskless fabrication technique that can effectively modify the optical,electrical,mechanical,and tribological properties of materials for a wide range of potential ***,the eventual implementation of fs-laser-treated surfaces in actual devices remains challenging because it is difficult to precisely control the surface *** studies of the morphological control of fs-laser-processed surfaces mostly focused on enhancing the uniformity of periodic ***,guided by the plasmon hybridisation model,we control the morphology of surface nanostructures to obtain more control over spectral light *** experimentally demonstrate spectral control of a variety of metals[copper(Cu),aluminium(Al),steel and tungsten(W)],resulting in the creation of broadband light absorbers and selective solar absorbers(SSAs).For the first time,we demonstrate that fs-laser-produced surfaces can be used as high-temperature *** show that a tungsten selective solar absorber(W-SSA)exhibits excellent performance as a high-temperature solar *** integrated into a solar thermoelectric generation(TEG)device,W-SSA provides a 130%increase in solar TEG efficiency compared to untreated W,which is commonly used as an intrinsic selective light absorber.

关键词： steel absorber metals

Contact pattern,current immune barrier,and pathogen virulence determines the optimal strategy of further vaccination

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Infectious Disease Modelling 2023年第1期8卷 192-202页

作者： Xiaohao guo Ziyan Liu Shiting Yang Zeyu Zhao Yichao guo Guzainuer Abudurusuli Shanlu Zhao Ge Zeng Shixiong Hu Kaiwei Luo Tianmu Chen State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics School of Public HealthXiamen UniversityXiamen City361102Fujian ProvincePeople's Republic of China Hunan Provincial Center for Disease Control and Prevention 405 Furong Middle Road Section OneKaifu DistrictChangsha City410001Hunan ProvincePeople's Republic of China

Background:The current outbreak of novel coronavirus disease 2019 has caused a seriousdisease burden *** are an important factor to sustain the *** with a relatively high-vaccination worldwide,the decay of vaccine efficacy andthe arising of new variants lead us to the challenge of maintaining a sufficient immunebarrier to protect the ***:A case-contact tracking data in Hunan,China,is used to estimate the contactpattern of cases for scenarios including school,workspace,etc,rather than ordinary susceptible *** on the estimated vaccine coverage and efficacy,a multi-groupvaccinated-exposed-presymptomatic-symptomatic-asymptomatic-removed model(VEFIAR)with 8 age groups,with each partitioned into 4 vaccination status groups *** optimal dose-wise vaccinating strategy is optimized based on the currentlyestimated immunity barrier of coverage and efficacy,using the greedy algorithm thatminimizes the cumulative cases,population size of hospitalization and fatality respectivelyin a certain future *** of Delta and Omicron variants are used respectivelyin the ***:The estimated contact matrices of cases showed a concentration on middle ages,and has compatible magnitudes compared to estimations from contact surveys in *** VEFIAR model is numerically *** optimal controled vaccination strategy requires immediate vaccination on the un-vaccinated high-contact population of age30e39 to reduce the cumulative cases,and is stable with different basic reproductionnumbers(R_(0)).As for minimizing hospitalization and fatality,the optimized strategy requires vaccination on the un-vaccinated of both aged 30e39 of high contact frequencyand the vulnerable ***:The objective of reducing transmission requires vaccination in age groups ofthe highest contact frequency,with more priority for un-vaccinated than un-fully or *** objective of reducing total ho

关键词： Vaccine Allocation strategy SARS-CoV-2 Optimal control Immune barrier Contact pattern Greedy algorithm

Influences of Reaction Parameters and Ce Contents on Structure and Properties of Nano-scale Ce-HA Powders

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Journal of Materials Science & Technology 2014年第8期30卷 776-781页

作者： L.J.Sun D.G.guo W.A.Zhao L.Y.Wang K.W.Xu State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi'an Jiaotong University Chao Family Comprehensive Cancer Center Department of Pharmaceutical SciencesUniversity of California Irvine Sue and bill Gross Stem Cell Research Center University of California Irvine The Key Laboratory of Bioactive Materials Ministry of EducationCollege of Life SciencesNankai University Xi'an University of Arts and Science

Ce-incorporated apatite（Ce-HA） nano-scale particles with different Ce percentage contents（atomic ratio of Ce to Ce ＋ Ca is 5%,10%and 20%,respectively） were synthesized via a simple wet chemical method in this *** crystal structure,chemical groups,thermal stability,crystal morphologies and crystal sizes of the Ce-HA nano-particles were characterized by X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR）,and transmission electron microscopy（TEM）.The influences of reaction temperature,reaction time,pH value,and the atomic ratio of Ce to Ce ＋ Ca on the structure and performance of Ce-HA particles were *** results show that the lattice constants,particle sizes,crystallinity and thermal stability of Ce-HA vary with the doped Ce *** the increase of Ce content,the lattice constants of the Ce-HA nano-particles remarkably increase but the particle size,crystallinity and thermal stability gradually *** reaction temperature as well as the reaction time has no significant effect on the properties of the final products,while the pH value has a direct relationship with their final chemical *** obtained Ce-HA nanosize particles possess potential application in preparing artificial bone implants,bone tissue engineering scaffold and other bioactive coatings.

关键词： Cerium Apatite Nano-scale powder Wet chemical approach Biomedical materials