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Chinese Physics B 2007年第2期16卷 374-381页

作者：熊庄 Bacalis n C AMS Research Center Southeast Uniwrsity Nanjing 210096 China Theoretical and Physical Chemistry Institute National Hellenic Research Foundation Vaslleos Constantinou 48 Athens 11635 Greece

By taking full account of the non-orthogonality of the orbitals between the low-lying doubly excited states ^1po and the singly excited states ^1S^e and ^1d^e of He, the corresponding radiative decay rates have been investigated theoretically via analytic generalized Laguerre-type atomic orbitals at a nearly numerical multi-conflguration self-consistent field accuracy in a general non-orthogonal configuration interaction scheme. From these rates, we calculate the VUV photon emission and metastable atom spectra, and both are found to be in good qualitative agreement with recent excellent measurements. We obtain, successfully, the enhancement of the VUV photon spectrum, experimentally observed at the energy of （2s4p-4s2p）/（2p,3d） ^1po as compared with other nearby lying states. The mechanism proposed by Odling-Smee et al is verified, implying that taking appropriate account of the overlap existing between orbitals of the low-lying doubly excited and singly excited states （especially important for the compact orbitals） can reveal basic physical dominant mechanism and is crucial in understanding these spectra.

关键词： doubly excited states, singly excited states analytic basis functions, non-orthogonality formalism

Viscoelastic Immersed Boundary Methods for Zero Reynolds number Flow

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Communications in Computational Physics 2012年第7期12卷 462-478页

作者： Wanda Strychalski Robert d.Guy department of Mathematics University of CaliforniaDavis CA 95616USA

The immersed boundary method has been extensively used to simulate the motion of elastic structures immersed in a viscous *** some applications,such as modeling biological materials,capturing internal boundary viscosity is *** present numerical methods for simulating Kelvin-Voigt and standard linear viscoelastic structures immersed in zero Reynolds number *** find that the explicit time immersed boundary update is unconditionally unstable above a critical boundary to fluid viscosity ratio for a Kelvin-Voigt *** also show there is a severe time step restriction when simulating a standard linear boundary with a small relaxation time scale using the same explicit update.A stable implicit method is presented to overcome these computation challenges.

关键词： Stokes flow viscoelastic structures fluid-structure interaction numerical instability

Mathematical analysis of a tuberculosis model with imperfect vaccine

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International Journal of Biomathematics 2019年第7期12卷 21-50页

作者： A.O.Egonmwan d.Okuonghae department of Mathematics University of Benin P.M.B.1154Benin CityNigeria

Since 1921,the Bacille Calmette Guerin(BCG)vaccine continues to be the most widely used vaccine for the prevention of Tuberculosis(TB).However,the immunity induced by BCG wanes out after some time making the vaccinated individual susceptible to TB *** this work,we formulate a mathematical model that incorporates the vaccination of newly born children and older susceptible individuals in the transmission dynamics of TB in a population,with a vaccine that can confer protection on older susceptible *** the absence of disease-induced deaths,the model is shown to undergo the phenomenon of backward bifurcation where a stable disease-free equilibrium(dFE)co-exists with a stable positive(endemic)equilibrium when the associated repro-duction number is less than *** is shown that this phenomenon does not exist in the absence of imperfect vaccine,exogenous reinfection,and reinfection of prev iously treated *** is further shown that a special case of the model has a unique endemic equilibrium point(EEP),which is globally asymptotically stable when the associated reproduction number exceeds *** and sensitivity analysis are carried out to identify key parameters that have the greatest infuence on the transmission dynamics of TB in the population using the total population of latently infected individuals,total number of actively infected individuals,disease incidence,and the effective reproduc-tion number as output *** analysis shows that the top five parameters of the model that have the greatest influence on the effective reproduction number of the model are the transmission rate,the fraction of fast disease progression,modification parame-ter which accounts for reduced likelihood to infection by vaccinated individuals due to imperfect vaccine,rate of progression from latent to active TB,and the treatment rate of actively infected individuals,with other key parameters infuencing the outcomes of the other output respons

关键词： Tuberculosis BCG imperfect vaccine mathematical model global stability bifurcation uncertainty and sensitivity analysis numerical simulations

Hydrodynamic Interaction of Elastic Capsules in Bounded Shear Flow

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Communications in Computational Physics 2014年第9期16卷 1031-1055页

作者： d.V.Le Zhijun Tan Institute of High Performance Computing Agency for ScienceTechnology and Research1 Fusionopolis Way#16-16 ConnexisSingapore 138632 School of Mathematics and Computational Science Sun Yat-sen UniversityGuangzhou 510275China Province Key Laboratory of Computational Science Sun Yat-sen UniversityGuangzhou 510275China.

This paper presents a modified Loop’s subdivision algorithm for studying the deformation of a single capsule,the hydrodynamic interaction between two capsules and the hydrodynamic diffusion of a suspension of capsules in bounded shear flow.A subdivision thin-shell model is employed to compute the forces generated on the surface of the elastic capsule during *** capsule surface is approximated using the modified Loop’s subdivision scheme which guarantees bounded curvature and C1 continuity everywhere on the limit *** present numerical technique has been validated by studying the deformation of a spherical capsule in shear *** are also performed for a biconcave capsule over a wide range of shear rates and viscosity ratios to investigate its *** addition,the hydrodynamic interaction between two elastic capsules in bounded shear flow is *** on the wall separation distance,the trajectory-bifurcation points that separate reversing and crossing motions for both spherical and biconcave capsules can be *** to the spherical capsules,the biconcave capsules exhibit additional types of interaction such as rotation and head-on *** head-on collision results in a large trajectory shift which contribute to the hydrodynamic diffusion of a suspension.A suspension of a large number of biconcave capsules in shear flow is also simulated to show the ability of the modified scheme in running a large-scale simulation over a long period of time.

关键词： Thin shell elastic capsules red-blood cells subdivision surfaces immersed boundary method navier-Stokes equations.

Hash-Indexing Block-Based deduplication Algorithm for Reducing Storage in the Cloud

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Computer Systems Science & Engineering 2023年第7期46卷 27-42页

作者： d.Viji S.Revathy department of Computer Science and Engineering Sathyabama Institute of Science and TechnologyChennaiIndia

Cloud storage is essential for managing user data to store and retrieve from the distributed data *** storage service is distributed as pay a service for accessing the size to collect the *** to the massive amount of data stored in the data centre containing similar information and file structures remaining in multi-copy,duplication leads to increase storage *** potential deduplication system doesn’t make efficient data reduction because of inaccuracy in finding similar data *** creates a complex nature to increase the storage consumption under *** resolve this problem,this paper proposes an efficient storage reduction called Hash-Indexing Block-based deduplication(HIBd)based on Segmented Bind Linkage(SBL)Methods for reducing storage in a cloud ***,preprocessing is done using the sparse augmentation ***,the preprocessed files are segmented into blocks to make *** block of the contents is compared with other files through Semantic Content Source deduplication(SCSd),which identifies the similar content presence between the *** on the content presence count,the distance Vector Weightage Correlation(dVWC)estimates the document similarity weight,and related files are grouped into a ***,the segmented bind linkage compares the document to find duplicate content in the cluster using similarity weight based on the coefficient match *** implementation helps identify the data redundancy efficiently and reduces the service cost in distributed cloud storage.

关键词： Cloud computing deduplication hash indexing relational content analysis document clustering cloud storage record linkage

Micromorphic theory:a gateway to nano world

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International Journal of Smart and nano Materials 2010年第2期1卷 115-135页

作者： Xianqiao Wang James d.Lee department of Mechanical and Aerospace Engineering The George Washington UniversityWashingtonDC 20052USA

Micromorphic theory(MMT)envisions a material body as a continuous collection of deformable particles;each possesses finite size and inner *** is considered as the most successful top-down formulation of a two-level continuum model,in which the deformation is expressed as a sum of macroscopic continuous deformation and internal microscopic deformation of the inner *** this work,the kinematics including the objective Eringen tensors is *** laws are derived by requiring the energy equation to be form-invariant under the generalized Galilean *** concept of material force and the balance law of pseudomomentum are generalized for *** axiomatic approach is demonstrated in the formulation of constitutive equations for a generalized micromorphic thermoviscoelastic solid,generalized micromorphic fluid,micromorphic plasticity,and micromorphic electromagnetic-thermoelastic *** of MMT in micro/nanoscale are discussed.

关键词： micromorphic theory Eringen tensors constitutive theory generalized micromorphic solid/fluid electromagnetic-thermoelastic coupling micro/nanomechanics

A Multigrid Method for a Model of the Implicit Immersed Boundary Equations

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Communications in Computational Physics 2012年第7期12卷 378-400页

作者： Robert d.Guy Bobby Philip department of Mathematics University of California DavisDavisCA 95616USA Oak Ridge national Laboratory Oak RidgeTN 37831USA

Explicit time stepping schemes for the immersed boundary method require very small time steps in order to maintain *** the equations that arise from an implicit discretization is ***,several different approaches have been proposed,but a complete understanding of this problem is still emerging.A multigrid method is developed and explored for solving the equations in an implicittime discretization of a model of the immersed boundary *** model problem consists of a scalar Poisson equation with conformation-dependent singular forces on an immersed *** model does not include the inertial terms or the incompressibility *** method is more efficient than an explicit method,but the efficiency gain is *** multigrid method alone may not be an effective solver,but when used as a preconditioner for Krylov methods,the speed-up over the explicit-time method is *** example,depending on the constitutive law for the boundary force,with a time step 100 times larger than the explicit method,the implicit method is about 15-100 times more efficient than the explicit method.A very attractive feature of this method is that the efficiency of the multigrid preconditioned Krylov solver is shown to be independent of the number of immersed boundary points.

关键词： Preconditioning implicit methods fluid-structure interaction

Enhanced fitness due to higher fecundity,increased defence against a specialist and tolerance towards a generalist herbivore in an invasive annual plant

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Journal of Plant Ecology 2009年第2期2卷 77-86页

作者： d.Abhilasha J.Joshi Institute of Environmental Sciences University of ZurichWinterthurerstrasse 190CH-8057 ZurichSwitzerland Institute of Biochemistry and Biology Biodiversity Research/BotanyUniversity of PotsdamMaulbeerallee 114469 PotsdamGermany

Aims The superior performance of many non-indigenous species in a new range can be attributed to different factors such as pre-adaptation to environmental conditions in new areas or to factors inherent to displacement mechanisms such as loss of co-evolved pathogens and herbivores that increase the speed of evolutionary change towards a shift in allocation from defence to growth and *** assess the importance of the different mechanisms governing the success of Conyza canadensis,a globally successful invader,we simultaneously tested several recent hypotheses potentially explaining the factors leading to biological *** We tested(i)whether plants from the non-native range showed a higher fitness than plants from the native north American range,(ii)whether they differed in resistance against an invasive generalist herbivore,the slug Arion lusitanicus and against a recently established specialist aphid herbivore,Uroleucon erigeronense and(iii)experimentally assessed whether *** releases allelopathic chemicals that have harmful effects on competing species in the nonnative *** compared populations along a similar latitudinal gradient both in the native north American and invasive European range and analysed patterns of adaptive clinal variation in biomass *** Findings The invasion success of *** in Europe cannot be attributed to a single trait,but to a combination of *** plants benefited from increased growth and above all,increased reproduction(a key trait in an annual plant)and were less attacked by a co-migrated specialist *** observed loss of defence against generalist slugs did not translate into a decreased fitness as invasive *** plants showed a high re-growth *** contrast to earlier in vitro studies,we detected no allelopathic effects on the competing flora in the non-native *** latitudinal cline in vegetative biomass production in the non-native range observ

关键词： allelopathy biological invasions Conyza canadensis EICA hypothesis generalist/specialist herbivory latitudinal clines biogeographic comparison common garden

Epigenetic effects of ethanol on liver and gastrointestinal injury

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World Journal of Gastroenterology 2006年第33期12卷 5265-5271页

作者： Shivendra d Shukla Annayya R Aroor department of Medical Pharmacology & Physiology University of Missouri School of Medicine Columbia Missouri 65212 United States

Alcohol consumption causes cellular injury. Recent developments indicate that ethanol induces epigenetic alterations, particularly acetylation, methylation of histones, and hypo- and hypermethylation of dnA. This has opened up a new area of interest in ethanol research and is providing novel insight into actions of ethanol at the nucleosomal level in relation to gene expression and patho-physiological consequences. The epigenetic effects are mainly attributable to ethanol metabolic stress (Emess), generated by the oxidative and non-oxidative metabolism of ethanol, and dysregulation of methionine metabolism. Epigenetic changes are important in ethanol-induced hepatic steatosis, fibrosis, carcinoma and gastrointestinal injury. This editorial highlights these new advances and its future potential.

关键词： Alcohol Alcoholic liver disease dnA methylation Epigenetics Ethanol Gastrointestinal injury Histone modifications Liver injury

Colorectal cancer surveillance in inflammatory bowel disease:Practice guidelines and recent developments

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World Journal of Gastroenterology 2019年第30期25卷 4148-4157页

作者： William T Clarke Joseph d Feuerstein department of Medicine and division of Gastroenterology Beth Israel Deaconess Medical Center Harvard Medical School

Patients with long-standing inflammatory bowel disease(IBd)involving at least 1/3 of the colon are at increased risk for colorectal cancer(CRC).Advancements in CRC screening and surveillance and improved treatment of IBd has reduced CRC incidence in patients with ulcerative colitis and Crohn’s *** cases of CRC are thought to arise from dysplasia,and recent evidence suggests that the majority of dysplastic lesions in patients with IBd are visible,in part thanks to advancements in high definition colonoscopy and *** practice guidelines have supported the use of chromoendoscopy with targeted biopsies of visible lesions rather than traditional random *** are encouraged to endoscopically resect visible dysplasia and only recommend surgery when a complete resection is not *** technologies such as virtual chromoendoscopy are emerging as potential tools in CRC *** with IBd at increased risk for developing CRC should undergo surveillance colonoscopy using new approaches and techniques.

关键词： Inflammatory bowel disease Colorectal cancer screening Ulcerative colitis Crohn’s disease Colonoscopy Chromoendoscopy