检索结果-南通市图书馆

On the Necessary Grid Resolution for Verified Calculation of Premixed Laminar Flames

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2010年第7期8卷 304-326页

作者： Ashraf N.Al-Khateeb Joseph m.Powers samuel Paolucci Department of Aerospace and mechanical Engineering University of Notre DameNotre DameIndiana 46556-5637USA

We consider the grid resolution necessary to resolve combustion in a mixture of calorically imperfect ideal gases described by detailed kinetics and multicomponent *** the steady premixed laminar flame as a paradigm,the required spatial discretization to capture all detailed physics in the reaction zone is found via 1)determination of the finest grid used in a standard software tool which employs adaptive mesh refinement,2)examination of peak values of intermediate species mass fractions in the flame zone as a function of grid size,3)a formal grid resolution study,and 4)a robust new eigenvalue analysis developed to estimate the finest length *** to laminar premixed flames in hydrogen-air flames reveals that the finest length scale is on the order of 10^(−4) cm for combustion at atmospheric *** at this scale is shown to be necessary to capture detailed species mass fraction profiles;other features such as steady flame speeds and equilibrium thermochemical properties do not have such a stringent length scale requirement.

关键词： Length scales premixed flames detailed kinetics

On a diffusive bacteriophage dynamical model for bacterial infections

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 2023年第7期16卷 47-89页

作者： Hyacinthe m.Ndongmo Teytsa Berge Tsanou Jean Lubuma samuel Bowong Department of mathematics and Computer Science University of Dschang P.O.Bor 67DschangCameroon Department of mathematics and Applied mathematics University of Pretoria Pretoria 0002South Africa IRD UmI 209 UmmISCO University of Yaounde I P..Bor 337YaoundeCameroon LIRImA-EPITAG Team Project University of Yaounde I P.O.Bor 812YaoundeCameroon Department of mathematics and Computer Science University of Douala P.0.Bor 24157DoualaCameroon

Bacteriophages or phages are viruses that infect bacteria and are increasingly used to control bacterial *** develop a reaction-diffusion model coupling the interactive dynamic of phages and bacteria with an epidemiological bacteria-borne disease *** the submodel without phage absorption,the basic reproduction number Ro is *** disease-free equilibrium(DFE)is shown to be globally asymptotically stable whenever Ro is less than one,while a unique globally asymptotically endemic equilibrium is proven whenever Ro exceeds *** the presence of phage absorption,the above stated classical condition based on Ro,as the average number of secondary human infections produced by susceptible/lysogen bacteria during their entire lifespan,is no longer suficient to guarantee the global stability of the *** thus derive an additional threshold No,which is the average offspring number of lysogen bacteria produced by one infected human during the phage-bacteria interactions,and prove that the DFE is globally asymptotically stable whenever both Ro and No are under unity,and infections persist uniformly whenever Ro is greater than ***,the discrete counterpart of the continuous partial differential equation model is derived by constructing a nonstandard finite difference scheme which is dynamically *** consistency is shown by constructing suitable discrete Lyapunov functionals thanks to which the global stability results for the continuous model are *** scheme is implemented in matLab platform and used to assess the impact of spatial distribution of phages,on the dynamic of bacterial infections.

关键词： Bacterial infections diffusion NSFD phage absorption global stability

The role of dietary nitrate supplementation in neurovascular function

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2021年第7期16卷 1419-1420页

作者： masahiro Horiuchi Gabriella m.K.Rossetti samuel J.Oliver Division of Human Environmental Science Mount Fuji Research InstituteYamanashiJapan School of Sport Health and Exercise SciencesCollege of Human SciencesBangor UniversityBangorUK

A healthy diet combined with increased physical activity levels may protect against cerebrovascular dysfunction and cognitive impairments(Gorelick et al., 2011).Compared with the number of studies on the effects of physical activity, studies on how diet affects cerebral blood flow(CBF) regulation and cognitive function are relatively ***, we focus on the potential role of dietary nitrate supplementation in CBF regulation and cognitive function under normoxic and hypoxic conditions.

关键词： al. nitrate conditions.

Short-term effect of supplemental yeast extract without or with feed enzymes on growth performance, immune status and gut structure of weaned pigs challenged with Escherichia coli lipopolysaccharide

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2017年第2期8卷 378-390页

作者： samuel m.Waititu Fugui Yin Rob Patterson Juan C.Rodriguez-Lecompte Charles m.Nyachoti Department of Animal Science University of Manitoba201-12 Dafoe RoadWinnipegM6 R3T 2N2Canada Canadian Bio-systems Inc. CalgaryAB T2C OJTCanada Atlantic Veterinary College University of Prince Edward IslandCharlottetownPE C1A 4P3Canada

Background： This study investigated the response of piglets receiving a yeast extract without or with a multi-enzyme mixture compared with an antimicrobial growth promoter（AGP） on performance, immune status and gut structure after an E. coli lipopolysaccharide（LPS） challenge. Thirty-six pigs were allotted to six treatments including： a non-challenged control（NCC）; LPS-challenged control（CC）; CC ＋ AGP; CC ＋ yeast extract; CC ＋ enzymes; and CC ＋ enzymes ＋ yeast extract. On d 7, pigs were bled and thereafter injected with LPS or sterile saline. Blood samples were collected at 6, 48, and 96 h post-challenge. After 96 h post-challenge, pigs were euthanized to obtain duodenal, jejunal and ileal ***： Overall（d 1 to 11）, compared with CC pigs, AGP attenuated the LPS-induced reduction in ADG（P = 0.004）,ADFI（P = 0.03） and gain/feed ratio（P = 0.01）. At 6 h post-challenge, AGP pigs had lower plasma urea N（PUN; P = 0.02）and serum TNF-α concentration（P = 0.07）, and higher platelet count（P = 0.04） and serum IL-10 concentration（P = 0.02） than CC pigs. At 48 h post-challenge, AGP pigs had lower PUN（P = 0.02） than CC pigs, whereas enzymes ＋ yeast extract interacted non-additively（P = 0.001） to reduce PUN. At 96 h post-challenge, AGP pigs had lower PUN（P = 0.02）and higher duodenal（P = 0.03）, jejunal（P = 0.01） and ileal（P = 0.07） villus height than CC pigs. In addition, enzymes ＋yeast extract interacted additively and non-additively to reduce ileal IFN-γ（P 0.10） were observed between AGP and enzymes ＋ yeast extract pigs on other measured parameters except for the downregulation of ileal IFN-γ（P ＆lt; 0.0001） and TNF-α（P = 0.003） in enzymes ＋ yeast extract pigs at 96 h ***： The LPS challenged piglets receiving enzymes ＋ yeast extract showed beneficial responses in gut structure and immunity commensurate with those receiving antibiotics, though the latter had better overall growth performance.

关键词： Antimicrobial growth promoter Feed enzymes Growth performance Immunity Nucleotides Piglets

The pleiotropic roles of cGAS-STING signaling in the tumor microenvironment

在线全文

学校读者我要写书评

暂无评论

Journal of molecular Cell Biology 2022年第4期14卷 18-26页

作者： Jun Li samuel F.Bakhoum Human Oncology and Pathogenesis Program Memoria loan Kettering Cancer CenterNew YorkNY 10065USA Department of Radiation Oncology Memorial Sloan Kettering Cancer CenterNew YorkNY 10065USA

Cytosolic DNA is prevalent in cells constituting the tumor microenvironment(TmE)and can activate the cyclic guanosine monophosphate-adenosine monophosphate synthase(cGAS)-stimulator of interferon genes(STING)innate immune *** initiation,transmission,and execution of the cGAS-STING pathway can take place among different cell types within the TmE and thus cGAS-STING may play opposing roles in driving tumor progression in addition to its tumor cell-intrinsic ***,we review recent advances in the cGAS-STING field with a focus on its crosstalk with other signaling pathways in the *** efforts to depict a more detailed picture of the roles of cGAS-STING signaling in the TmE wil help design a better cancer treatment regime by targeting the cGAS-STING pathway more precisely.

关键词： immunity the tumor microenvironment DNA sensing

A Novel Intermediate Bus Converter Topology for Cutting Edge Data Center Applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electrical Engineering 2020年第4期6卷 3-14页

作者： samuel Webb Yan-Fei Liu Department of Electrical and Computer Engineering Queen’s UniversityKingston K7L 3N6Canada

As new technologies emerge data centers and servers have established themselves as one of the largest and fastest growing consumers of *** switched capacitor converter topologies have some very attractive features,namely low reliance on magnetic components and high efficiency,several critical factors have prevented their adoption in high current data center *** family of converters proposed are novel intermediate bus converter that demonstrates the highest performance yet achieved for 48 V to 12 V conversion with up to 2.5 kW/in^(3) power density,higher than 99% peak efficiency,and 97.2% full load efficiency for 12 V/70 A *** reduction of voltage stress across the mOSFETs as well as extremely low reliance on magnetics are the key driving factors behind this high efficiency and power density,and are achieved without a sensitive resonant design or the usage of complex control technique.

关键词： DC-DC converter data centers intermediate bus architecture

Determination of the magnetic fields of magellanic X-ray pulsars

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2017年第6期17卷 95-100页

作者： Dimitris m. Christodoulou Silas G. T. Laycock Jun Yang samuel Fingerman Lowell Center for Space Science and Technology University of Massachusetts Lowell Lowell MA 01854 USA Department of mathematical Sciences University of Massachusetts Lowell Lowell MA 01854 USA Department of Physics & Applied Physics University of Massachusetts Lowell Lowell MA 01854 USA

The 80 high-mass X-ray binary （HmXB） pulsars that are known to reside in the magellanic Clouds （mCs） have been observed by the Xmm-Newton and Chandra X-ray telescopes on a regular basis for 15 years, and the Xmm-Newton and Chandra archives contain nearly complete information about the duty cycles of the sources with spin periods Ps 〈 100 s. We have reprocessed the archival data from both observatories and we combined the output products with all the published observations of 31 mC pulsars with Ps 〈 100 s in an attempt to investigate the faintest X-ray emission states of these objects that occur when accretion to the polar caps proceeds at the smallest possible rates. These states determine the so-called propeller lines of the accreting pulsars and yield information about the magnitudes of their surface magnetic fields. We have found that the faintest states of the pulsars segregate into five discrete groups which obey to a high degree of accuracy the theoretical relation between spin period and X-ray luminosity. So the entire population of these pulsars can be described by just five propeller lines and the five corresponding magnetic moments （0.29, 0.53, 1.2, 2.9 and 7.3, in units of 1030 G cma）.

关键词： magellanic clouds - accretion, accretion disks - stars magnetic field - stars neutron- X-rays binaries

Institutional Capacity and the Roles of Key Actors in Fire Disaster Risk Reduction: The Case of Ibadan, Nigeria

在线全文

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2022年第5期13卷 716-728页

作者： Olusegun Joseph Falola samuel Babatunde Agbola Department of Urban and Regional Planning Lead City UniversityIbadan 200255Oyo StateNigeria Department of Urban and Regional Planning University of IbadanIbadan 200284Oyo StateNigeria

Inefficient and ineffective fire management practices are common to most urban areas of developing *** cities are typical examples of high vulnerability and low preparedness level for fire *** study examined the institutional framework for fire disaster risk reduction(FDRR) and explored the roles of key actors in fire disaster preparedness in Ibadan,a large traditional city in *** study was anchored on the concept of urban governance.A case study research design was adopted using primary and secondary *** data were obtained through field observation aided by a structured checklist and key informant *** were conducted on key officials of the major organs for FDRR-Oyo State Fire Service(OSFS) and Oyo State Emergency management Agency(OYSEmA).The study identified a disjointed and fragmented approach to fire *** relating to fire risk reduction and disaster recovery were domiciled under the OYSEmA,while emergency response to fire disasters was the prerogative of the *** results show that only five out of 11 local government areas had public fire stations;only three fire stations had an on-site water supply;three fire stations lacked firefighting vehicles;and distribution of fire stations and facilities was *** fire stations responded to 80% of all fire cases in 12 *** study concluded that the institutional structure and resources for fire risk reduction was more empowered to respond to fire disaster,rather than facilitating preparedness capacity to reduce disaster risk.

关键词： Disaster preparedness Disaster risk Fire disaster Fire service Fire station

The rhizosphere microbial complex in plant health:A review of interaction dynamics

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2022年第8期21卷 2168-2182页

作者： Oluwaseyi samuel OLANREWAJU Olubukola Oluranti BABALOLA Food Security and Safety Focus Area Faculty of Natural and Agricultural SciencesNorth-West UniversityMmabatho 2735South Africa

Climate change,urbanization,and population increase limit food *** sustain human existence,there is the need to increase food and agricultural production to mitigate the impact of these *** have been working for years on ways to increase food *** plant breeding techniques to soil science,scientists have made tremendous *** rhizobiome has been proven to be important to crop production,and the impact of the rhizobiome on plant health cannot be *** rich in diverse complex microbial interactions,the rhizosphere has become a major force in recent plant growth promotion *** upsurge in next-generation sequencing applications with the various“omics”technologies is helping to unearth information relating to rhizosphere impact on plant *** the complex interactions between and across microbial species present in the rhizosphere is important to further enhance our understanding of their mechanistic and mutualistic *** from this can be used in rhizosphere biome engineering for improved plant growth and yield in the face of the various biotic and abiotic challenges.

关键词： below-ground interactions climate change plant growth promotion plant microbiome root exudation