检索结果-南通市图书馆

dynamic responses of two buildings connected by viscoelastic dampers under bidirectional earthquake excitations

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2014年第1期13卷 137-150页

作者： Z.d. Yang Eddie s.s. Lam department of Civil and Environmental Engineering The Hong Kong Polytechnic University

In this study,dynamic responses of two buildings connected by viscoelastic dampers under bidirectional excitations are extensively *** two buildings are a 10-story building and a 16-story building,with the shorter building on the *** dampers are installed at all fl oors of the shorter *** of motion are formulated using a fractional derivative model to represent the viscoelastic *** cases are considered with mass eccentricities at 0,10% and-10% with respect to the dimensions of the *** responses of the buildings are numerically predicted at different damper *** simulation results indicated that the maximum horizontal responses of the buildings without eccentricities are signifi cantly ***,torsional effects are adversely *** asymmetric buildings,the effectiveness of the connecting dampers is affected by building *** a result,mass eccentricities must be taken into account in damper *** compared with vibrations induced by unidirectional excitations,bidirectional excitations can increase the responses of coupled asymmetric *** addition,installing dampers only at the top fl oor of the shorter building may cause a sudden change in lateral stiffness of the taller ***,the story shear envelopes of the taller building are changed.

关键词： bidirectional excitations connecting dampers adjacent buildings fractional derivative

Performance of Chemical Vapor deposited Boron-doped AlN Thin Film as Thermal Interface Materials for 3-W LEd: Thermal and Optical Analysis

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English Letters) 2018年第1期31卷 97-104页

作者： s. shanmugan d. Mutharasu Nano Optoelectronics Research Laboratory School of Physics Universiti Sains Malaysia (USM) 11800 Minden Pulau Pinang Malaysia

Boron-doped aluminum nitride （B-AlN） thin films were synthesized on Al substrates by using chemical vapor deposition method by changing the synthesis parameters and were used as thermal interface material for high power light emitting diode （LEd）. The B-AlN thin film-coated Al substrate was used as heat sink and studied the performance of high power LEd at various driving currents. The recorded transient cooling curve was evaluated to study the rise in junction temperature （Tj）, total thermal resistance （gth_tot） and the substrate thermal resistance （Rth_sub） of the given LEd. From the results, the B-AlN thin film （prepared at process 4） interfaced LEd showed low Rth-tot and Tj value for all driving currents and observed high difference in Rth_tot （△Rth_tot =2.2 K/W） at 700 mA when compared with the Rth-tot of LEd attached on bare Al substrates （LEd/Al）. The Tj of LEd was reduced considerably and observed 4.7 ℃ as ATj for the film prepared using process 4 condition when compared with LEd/Al boundary condition at 700 mA. The optical performance of LEd was also tested for all boundary conditions and showed improved lux values for the given LEd at 700 mA where B-AlN thin film was synthesized using optimized flow of Al, B and N sources with minimized B and N content. The other optical parameters such as color correlated temperature and color rendering index were also measured and observed low difference for all boundary conditions. The observed results are suggested to use B-AlN thin film as efficient solid thin film thermal interface materials in high power LEd.

关键词： Light emitting diode (LEd) B-AIN thin film Chemical vapor deposition (CVd) Thermal transient analysis Junction temperature Optical performance

Combinatorial therapies for spinal cord injury repair

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第5期20卷 1293-1308页

作者： Carla s.sousa Andreia Monteiro António J.salgado Nuno A.silva Life and Health sciences Research Institute(ICVs) School of MedicineUniversity of MinhoCampus de Gualtar-gualtarBragaPortugal ICVs/3B’s Associate Lab PT Government Associated LabCampus de Gualtar-gualtarBragaPortugal

spinal cord injuries have profound detrimental effects on individuals, regardless of whether they are caused by trauma or non-traumatic events. The compromised regeneration of the spinal cord is primarily attributed to damaged neurons, inhibitory molecules, dysfunctional immune response, and glial scarring. Unfortunately, currently, there are no effective treatments available that can fully repair the spinal cord and improve functional outcomes. Nevertheless, numerous pre-clinical approaches have been studied for spinal cord injury recovery, including using biomaterials, cells, drugs, or technological-based strategies. Combinatorial treatments, which target various aspects of spinal cord injury pathophysiology, have been extensively tested in the last decade. These approaches aim to synergistically enhance repair processes by addressing various obstacles faced during spinal cord regeneration. Thus, this review intends to provide scientists and clinicians with an overview of pre-clinical combinatorial approaches that have been developed toward the solution of spinal cord regeneration as well as update the current knowledge about spinal cord injury pathophysiology with an emphasis on the current clinical management.

关键词： electric stimulation neural tissue regeneration neuroprotection polytherapy spinal cord injury

Model dependent analysis of d^(+)_(s)→η^(′)l+v_(l) decays in beyond standard model

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第9期48卷 82-95页

作者： s.Mahata M.Mandal H.Mahapatra s.Biswas s.sahoo department of Physics National Institute of Technology Durgapur Durgapur 713209West BengalIndia

Motivated by the recent experimental results of branching fractions for d^(+)_(s)→η^(′)l+v_(l) decays,which deviate from their sM predictions,we hve investigated these decays in W' model and scalar leptoquark model to determine potential signatures of new physics(NP) in semileptonic charm decays induced by c→(s,d)l+v_(l) *** recent experimental results of branching fractions for semileptonic d meson decays,new coupling parameters are predicted for the aforementioned NP *** fraction,forward-backward asymmetry,and lepton polarization asymmetry are examined by considering the predicted NP coupling *** results of branching fractions in scalar leptoquark model are found very close to the experimental results and exist around the range of 1σ *** presented a comparative study of the NP models to check their sensitivity on these *** anticipate that further research on these decays will significantly support our findings.

关键词： charm decay new physics W′boson scalar leptoquark flavour changing charged current

Application of integrated simulation environment sIEMNEd to the analysis of the MEPHIsT-0 tokamak operation

在线全文

学校读者我要写书评

暂无评论

Plasma science and Technology 2023年第3期25卷 222-233页

作者： d Yu sYCHUGOV s Yu sOLOVIEV A s ZHILKIN A V MELNIKOV s A KRAT Faculty of Computational Mathematics and Cybernetics Lomonosov Moscow State University National Research Centre Kurchatov Institute National Research Nuclear University Moscow Engineering Physics Institute National University Moscow Institute of Physics and Technology

This paper presents the results of numerical simulation of plasma equilibrium and stability in the MEPHIsT-0 tokamak with sIEMNEd software and comparison of simulation results with *** determined characteristics of the vacuum chamber show that it significantly affects the entire *** various scenarios of the inductor operation,a comparison of experimental data and simulated currents and magnetic fields induced in the chamber was carried *** steady-state tokamak operation,a numerical study of equilibrium plasma configurations was carried out depending on the currents in the poloidal magnetic field coils and plasma *** vertical plasma instability was *** limiting values of plasma ellipticity preventing the vertical plasma instability were numerically *** simulations show that plasma equilibrium is supported by induced *** was shown numerically that magnetic configuration with‘zero of higher order’were obtained before the plasma shot,suggesting consistency between the simulation results and observations.

关键词： mathematical modelling tokamak installation MEPHIsT-0

Flexural-wave-generation using a phononic crystal with a piezoelectric defect

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2023年第8期44卷 1241-1262页

作者： s.H.JO d.LEE department of Mechanical Roboticsand Energy EngineeringDongguk UniversitySeoul 04620Republic of Korea department of Mechanical Engineering Seoul National UniversitySeoul 08826Republic of Korea

This paper proposes a method to amplify the performance of a flexural-wave-generation system by utilizing the energy-localization characteristics of a phononic crystal(PnC)with a piezoelectric defect and an analytical approach that accelerates the predictions of such wave-generation *** proposed analytical model is based on the Euler-Bernoulli beam *** proposed analytical approach,inspired by the transfer matrix and s-parameter methods,is used to perform band-structure and time-harmonic analyses.A comparison of the results of the proposed approach with those of the finite element method validates the high predictive capability and time efficiency of the proposed model.A case study is explored;the results demonstrate an almost ten-fold amplification of the velocity amplitudes of flexural waves leaving at a defect-band frequency,compared with a system without the ***,design guidelines for piezoelectric-defect-introduced PnCs are provided by analyzing the changes in wave-generation performance that arise depending on the defect location.

关键词： phononic crystal(PnC) defect wave-generation fexural wave analytical model

Arbuscular Mycorrhiza Prevents suppression of Actual Nitrification Rates in the (Myco-)Rhizosphere of Plantago lanceolata

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2012年第2期22卷 225-229页

作者： s.d.VEREsOGLOU Faculty of Agriculture Laboratory of Ecology and Environmental ProtectionAristotle University of Thessaloniki

The vast majority of herbaceous plants engage into arbuscular mycorrhizal (AM) symbioses and consideration of their mycorrhizal status should be embodied in studies of plant-microbe interactions. To establish reliable AM contrasts, however, a sterilized re-inoculation procedure is commonly adopted. It was questioned whether the specific approach is sufficient for the studies targeting the bacterial domain, specifically nitrifiers, a group of autotrophic, slow growing microbes. In a controlled experiment mycorrhizal and non-mycorrhizal Plantago lanceolata were grown up in compartmentalized pots to study the AM effect on nitrification rates in the plant rhizosphere. Nitrification rates were assayed following an extensive 3-week bacterial equilibration step of the re-inoculated soil and a 13-week plant growth period in a controlled environment. Under these specific conditions, the nitrification potential levels at harvest were exceptionally low, and actual nitrification rates of the root compartment of non-mycorrhizal P. lanceolata were significantly lower than those of any other compartment. It is then argued that the specific effects should be attributed to the alleged higher growth rates of non-mycorrhizal plants that are known to occur early in the AM experiment. It is concluded that the specific experimental approach is not suitable for the study of microbes with slow growth rates.

关键词： ammonia oxidizers nitrification potential plant-microbe interaction root compartment

Optomechanical dark state in a dual-species Bose-Einstein Condensate

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2012年第10期58卷 551-556页

作者：景辉 d.s. Goldbaum department of Physics Henan Normal University B2 Institute Department of Physics and College of Optical SciencesThe University of Arizona

We study cavity optomechanics of ultracold dual-species atomic mixtures with nonlinear *** interactions provide a direct parametric coupling of fictitious mechanical elements which,through interfering with the intracavity optical field,leads to a switchable optically-dark state for either *** demonstrates a matterwave analog of recently observed mechanical wave mixing and quantum motional-state swapping,with applications in the construction of integrated phononic devices,and the cavity-enhanced detection of quantum degenerate atomic mixtures.

关键词： optomechanics Bose-Einstein condensate bistability

Anaerobic soil disinfestation:A chemical-independent approach to pre-plant control of plant pathogens

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2015年第11期14卷 2309-2318页

作者： s L strauss d A Kluepfel UsdA-ARs Crops Pathology and Genetics Research Unit University of California

due to increasing regulations and restrictions, there is an urgent need to develop effective alternatives to chemical-dependent fumigation control of soilborne pests and pathogens. Anaerobic soil disinfestation （Asd） is one such alternative showing great promise for use in the control of soilborne pathogens and pests. This method involves the application of a carbon source, irrigation to field capacity, and covering the soil with a plastic tarp. While the mechanisms of Asd are not completely understood, they appear to be a combination of changes in the soil microbial community composition, production of volatile organic compounds, and the generation of lethal anaerobic conditions. The variety of materials and options for Asd application, including carbon sources, soil temperature, and plastic tarp type, influence the efficacy of pathogen sup- pression and disease control. Currently, both dry （e.g., rice bran） and liquid （e.g., ethanol） carbon sources are commonly used, but with different results depending on environmental conditions. While solarization is not an essential component of Asd, it can enhance efficacy. Understanding the mechanisms that mediate biological changes occurring in the soil during Asd will facilitate our ability to increase Asd efficacy while enhancing its commercial viability.

关键词： anaerobic soil disinfestation biological soil disinfestation soilborne pathogens fumigation