检索结果-南通市图书馆

Journal of Environmental Sciences 2009年第6期21卷 858-864页

作者： SHARMA Ashwani THAKUR Indu Shekhar Environmental Biotechnology Laboratory School of Environmental SciencesJawaharlal Nehru UniversityNew Mehrauli Road

A bacterial consortium was developed by continuous enrichment of microbial population isolated from sediment core of pulp and paper mill effluent in mineral salts medium（MSM） supplemented with pentachlorophenol（PCP） as sole source of carbon and energy in the *** consortia contained three bacterial *** were identified as Escherichia coli,Pseudomonas aeruginosa and Acinetobacter *** 16S rRNA gene sequence *** *** degraded PCP through the formation of tetrachloro-p-hydroquinone（TecH）,2-chloro-1,4-benzenediol and products of ortho ring cleavage detected by gas chromatograph/mass spectrometer（GC-MS）.Out of the three acclimated PCP degrading bacterial strains only one strain,Acinetobacter *** the presence of integron gene cassette as a marker of its stability and antibiotic *** strain possessed a 4.17 kb amplicon with 22 ORF＇*** plasmid isolated from the Acinetobacter *** subjected to shotgun cloning through restriction digestion by BamHI,HindIII and SalI,ligated to pUC19 vector and transformed into *** XLBlue1α,and finally selected on MSM containing PCP as sole source of carbon and energy with ampicillin as antibiotic *** sequence analysis of recombinant clones indicated homology with integron gene cassette and multiple antibiotic resistance genes.

关键词： Acinetobacter sp. antibiotic resistance gene chemostat integron gene cassette pentachlorophenol recombinant clone

Impulsive perturbation and bifurcation of solutions for a model of chemostat with variable yield

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2009年第7期30卷 933-944页

作者：张弘 Paul Georgescu Juan J.Nieto 陈兰荪 Department of Mathematics Jiangsu University Department of Mathematics and Mathematical Statistics Ume University Department of Mathematics "Gh.Asachi" Technical University of Iasi Departamento de Análisis Matemático Facultad de Matemáticas Universidadde Santiago de Compostela Institute of Mathematics Chinese Academy of Sciences

In this paper, we consider a variable yield model of a single-species growth in a well-stirred tank containing fresh medium, assuming the instances of time as triggering factors in which the nutrient refilling process and the removal of microorganisms by the uptake of lethal external antibiotic are initiated. It is also assumed that the periodic nutrient refilling and the periodic antibiotic injection occur with the same periodicity, but not simultaneously. The model is then formulated in terms of autonomous differential equations subject to impulsive perturbations. It is observed that either the population of microorganisms essentially washes out, or more favorably, the system is permanent. To describe this dichotomy, some biologically significant integral conditions are introduced. Further, it is shown that in a certain critical situation, a nontriviai periodic solution emerges via a bifurcation phenomenon. Finally, the dynamics of the model is illustrated with numerical experiments and computer simulations.

关键词： chemostat impulsive differential equation permanence extinction fixedpoint approach bifurcation

Qualitative analysis of a chemostat model with inhibitory exponential substrate uptake and a time delay

在线全文

学校读者我要写书评

暂无评论

International Journal of Biomathematics 2014年第4期7卷 185-200页

作者： Qinglai Dong Wanbiao Ma School of Mathematics and Computer ScienceYanan University Yanan 716000 P. R. China School of Mathematics and PhysicsUniversity of Science and Technology Beijing Beijing 100083 P. R. China

In this paper, we consider a simple chemostat model with inhibitory exponential sub- strate uptake and a time delay. A detailed qualitative analysis about existence and boundedness of its solutions and the local asymptotic stability of its equilibria are car- ried out. Using Lyapunov-LaSalle invariance principle, we show that the washout equi- librium is global asymptotic stability for any time delay. Using the fluctuation lemma, the sufficient condition of the global asymptotic stability of the positive equilibrium E＋ is obtained. Numerical simulations are also performed to illustrate the results.

关键词： chemostat time delay stability Lyapunov LaSalle invariance principle.

Interspecific density-dependent model of predator-prey relationship in the chemostat

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Biomathematics 2021年第1期14卷 51-72页

作者： Tahani Mtar Radhouane Fekih-Salem Tewfik Sari University of Tunis El Manar National Engineering School of TunisLAMSIN 1002TunisTunisia University of Monastir Higher Institute of Computer Science of Mahdia5111 MahdiaTunisia ITAP Univ MontpellierINRAEInstitut AgroMontpellierFrance

The objective of this study is to analyze a model of competition for one resource in the chemostat with general interspecific density-dependent growth rates,taking into account the predator–prey *** relationship is characterized by the fact that the prey species promotes the growth of the predator species which in turn inhibits the growth of the first *** model is a three-dimensional system of ordinary differential *** the same dilution rates,the model can be reduced to a planar system where the two models have the same local and even global *** existence and stability conditions of all steady states of the reduced model in the plane are determined according to the operating *** the nullcline method,we present a geometric characterization of the existence and stability of all equilibria showing the multiplicity of coexistence steady *** bifurcation diagrams illustrate that the steady states can appear or disappear only through saddle-node or transcritical ***,the operating diagrams describe the asymptotic behavior of this system by varying the control parameters and show the effect of the inhibition of predation on the emergence of the bistability region and the reduction until the disappearance of the coexistence region by increasing this inhibition parameter.

关键词： Bifurcation chemostat coexistence predator-prey relationship operating diagram

Stationary distribution and periodic solution of stochastic chemostat models with single-species growth on two nutrients

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Biomathematics 2019年第6期12卷 23-41页

作者： Miaomiao Gao Daqing Jiang Taxawar Haya College of Science China University o/Petroleum(Haul China)Qingdao 266580P.R.China Keg laboratory of Unconventional Oil and Cos Development China University of Petroleum(East China)Ministry of Education.Qingdao 260580.P.It.China Nonlinear Analysis and Applied Mathematics(NAAM)-Research Group Department of Mathematics.King Abdulaziz University Jeddah 21589 Saudi Arabia Department of Mathematics Quaid-I-Azam University 45320 Islamabad 44000.Pakistan

In this paper,we consider two chemostat models w th random perturbation,in which single species depends on two perfectly substitutable resources for *** the autonomous system,we first prove that the solution of the system is positive and *** we establish sufficient conditions for the existence of an ergodic stationary distribu tion by constructing appropriate Lyapunov functions-For the non-autonomous system,by using Mas'minskii theory on periodic Markov processes,we derive it admits a nontriv ial positive periodic ***,numerical simulations are carried out to illustrate our main results.

关键词： chemostat model Lyapunov function stationary distribution Markov pro cess periodic solution.

Multiplicity results for the unstirred chemostat model with general response functions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2013年第10期56卷 2035-2050页

作者： NIE Hua WU JianHua College of Mathematics and Information Science Shaanxi Normal University

We investigate the multiplicity of positive steady state solutions to the unstirred chemostat model with general response functions. It turns out that all positive steady state solutions to this model lie on a single smooth solution curve, whose properties determine the multiplicity of positive steady state solutions. The key point of our analysis is to study the ＂turning points＂ on this positive steady state solution curve, and to prove that any nontrivial solution to the associated linearized problem is one of sign by constructing a suitable test function. The main tools used here include bifurcation theory, monotone method, mountain passing lemma and Sturm comnarison theorem.

关键词： chemostat general response function multiplicity bifurcation theory Sturm comparison theorem

Asymptotic Behavior on a Competition Model Arising from an Unstirred chemostat

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2006年第2期22卷 257-264页

作者： Hua Nie Jian-hua Wu College of Mathematics and Information Science Shaanxi Normal University Xi'an 710062 China

This paper is concerned with the unstirred chemostat model with two-species and one non-reproducing resource. The global attractivity of the positive steady-state solutions of the original system is established. Moreo... 详细信息

关键词： chemostat steady-state solution monotone method global attractivity

Spatial Pattern Induced by Cross-Diffusion in a chemostat Model with Maintenance Energy

在线全文

学校读者我要写书评

暂无评论

Journal of Donghua University(English Edition) 2018年第6期35卷 469-472页

作者： LIU Qingsheng PENG Yahong College of Science Donghua University

A chemostat model with maintenance energy and crossdiffusion is considered,and the formation of patterns is caused by the cross-diffusion. First, through linear stability analysis, the necessary conditions for the formation of the spatial patterns are given. Then numerical simulations by changing the values of crossdiffusions in the unstable domain are performed. The results showthat the cross-diffusion coefficient plays an important role in the formation of the pattern, and the different values of the crossdiffusion coefficients may lead to different types of pattern formation.

关键词： pattern formation chemostat model cross-diffusion Turing instability stability

Spatial Dynamics of Competing Model in a Periodic Unstirred chemostat with Delay

在线全文

学校读者我要写书评

暂无评论

Journal of Mathematical Research with Applications 2021年第4期41卷 368-382页

作者： Wujun PU Ya WANG Department of Mathematics Longnan Teachers College School of Mathematics and Statistics Lanzhou University

In this paper, we propose two species competition model in a chemostat that uses a nonlocal delayed chemostat model of a single species feeding on a periodically varying input nutrient. By the theory of semigroup, the existence and uniqueness of solution of the system is obtained. Furthermore, we show the competitive exclusion principle for the model, and the sufficient conditions of the coexistence of the system is established.

关键词： chemostat nonlocal delay competition exclusion principle coexistence

Direct Interference on Competition in a chemostat

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

生物数学学报 1998年第3期13卷 282-291页

作者： GailS.K.Wolkowicz,LuZhiqi DepartmentofMathematicsandStatistics McMasterUniversity!Hamilton Ontario CanadaL8s4K1 DepartmentofMathematics HenanTeacher'sUniversity!Xinxiang Henan 453002P.R.China

Thispaperstudiestheglobaldynamicsofcompetitioninchemostatinwhichtwopopulationsofmicrooganismscompeteexploitativelyforasingle,essential,nonreproducing,growth-l***ndinterspecificinterference,***:##4Populationdynamicseco... 详细信息

关键词： Populationdynamicsecology chemostat competition interference interspecific intraspecific principalofcompetitiveexclusion