检索结果-南通市图书馆

Tipping points among social learners： Tools from varied disciplines

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2012年第2期58卷 298-306页

作者： R. Alexander BENTLEY michael j. O＇BRIEN Department of Archaeology and Anthropology University of Bristol Bristol BS8 1UU UK Department of Anthropology University of Missouri Columbia MO 65211 USA

There is a long and rich tradition in the social sciences of using models of collective behavior in animals as j.mp- ing-off points for the study of human behavior, including collective human behavior. Here, we come at the problem in a slightly different fashion. We ask whether models of collective human behavior have anything to offer those who study animal behavior. Our brief example of tipping points, a model first developed in the physical sciences and later used in the social sciences, suggests that the analysis of human collective behavior does indeed have considerable to offer

关键词： Networks Social learning Thresholds Time series Tipping points

Inter-signal interaction and uncertain information in anuran multimodal signals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2011年第2期57卷 153-161页

作者： Ryan C. TAYLOR Barrett A. KLEIN michael j. RYAN Department of Biological Sciences Salisbury University Salisbury MD 21801 USA Section of Integrative Biology University of Texas at Austin Austin TX 78712 USA Smithsonian Tropical Research Institute P.O. Box 0843-03092 Balboa Ancon Republic of Panama

Disentangling the influence of multiple signal components on receivers and elucidating general processes influencing complex signal evolution are difficult tasks. In this study we test mate preferences of female squirrel treefrogs Hyla squirella and female tungara frogs Physalaemus pustulosus for similar combinations of acoustic and visual components of their multimodal courtship signals. In a two-choice playback experiment with squirrel treefrogs, the visual stimulus of a male model significantly increased the attractivness of a relatively unattractive slow call rate. A previous study demonstrated that faster call rates are more attractive to female squirrel treefrogs, and all else being equal, models of male frogs with large body stripes are more attractive. In a similar experiment with female tungara frogs, the visual stimulus of a robotic frog failed to increase the attractiveness of a relatively unattractive call. Females also showed no preference for the distinct stripe on the robot that males commonly bear on their throat. Thus, features of conspicuous signal components such as body stripes are not universally important and signal function is likely to differ even among species with similar ecologies and communication systems. Finally, we discuss the putative information content of anuran signals and suggest that the categorization of redundant versus multiple messages may not be sufficient as a general explanation for the evolution of multimodal signaling. Instead of relying on untested assumptions concerning the information content of signals, we discuss the value of initially collecting comparative empirical data sets related to receiver responses.

关键词： Inter-signal interaction Multimodal signaling Signal detection Signal weighting Squirrel treefrog Hyla squirella Tfingara frog Physalaemus pustulosus Vocal sac

Sharp Interpolation Inequalities on the Sphere:New Methods and Consequences

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 Annals of Mathematics,Series B 2013年第1期34卷 99-112页

作者： j.an DOLBEAULT Maria j. ESTEBAN Michal KOWALCZYK michael LOSS Ceremade Université Paris DauphinePlace de Lattre de Tassigny Departamento de Ingeniería Matemática and Centro de Modelamiento Matemático (UMI 2807 CNRS) Universidad de Chile Skiles Building Georgia Institute of Technology

This paper is devoted to various considerations on a family of sharp interpo- lation inequalities on the sphere, which in dimension greater than 1 interpolate between Poincare, logarithmic Sobolev and critical Sobolev （Onofri in dimension two） inequalities. The connection between optimal constants and spectral properties of the Laplace-Beltrami operator on the sphere is emphasized. The authors address a series of related observations and give proofs based on symmetrization and the ultraspherical setting.

关键词： Sobolev inequality Interpolation Gagliardo-Nirenberg inequality Logarithmic Sobolev inequality Heat equation

Apples to oranges:environmentally derived,dynamic regulation of serotonin neuron subpopulations in adulthood?

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第9期20卷 2596-2597页

作者： Christopher j.O’Connell Matthew j.Robson Department of Genetics College of MedicineHarvard UniversityBostonMAUSA j.mes L.Winkle College of Pharmacy Division of Pharmaceutical SciencesUniversity of CincinnatiCincinnatiOHUSA Neuroscience Graduate Program College of MedicineUniversity of CincinnatiCincinnatiOHUSA

Traumatic brain inj.ry(TBI)is a public health problem with an undue economic burden that impacts nearly every age,ethnic,and gender group across the globe(Capizzi et al.,2020).TBIs are often sustained during a dynamic range of exposures to energetic environmental forces and as such outcomes are typically heterogeneous regarding severity and pathology(Capizzi et al.,2020).

关键词： sustained orange dynamic

A decision framework for identifying models to estimate forest ecosystem services gains from restoration

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2016年第2期3卷 126-137页

作者： Zachary L. Christin Kenneth j. Bagstad michael A. Verdone Earth Economics 107 N Tacoma Ave Tacoma WA 98403 USA. U.S. Geological Survey Geosciences & Environmental Change Science Center Box 25046 MS 980 Denver CO 80225 USA. International Union for the Conservation of Nature 1630 Connecticut Ave. NW #300 Washington DC 20009 USA.

Restoring degraded forests and agricultural lands has become a global conservation priority. A growing number of tools can quantify ecosystem service tradeoffs associated with forest restoration. This evolving ＂tools landscape＂ presents a dilemma： more tools are available, but selecting appropriate tools has become more challenging. We present a Restoration Ecosystem Service Tool Selector （RESTS） framework that describes key characteristics of 13 ecosystem service assessment tools. Analysts enter information about their decision context, services to be analyzed, and desired outputs. Tools are filtered and presented based on five evaluative criteria： scalability, cost, time requirements, handling of uncertainty, and applicability to benefit-cost analysis. RESTS uses a spreadsheet interface but a web-based interface is planned. Given the rapid evolution of ecosystem services science, RESTS provides an adaptable framework to guide forest restoration decision makers toward tools that can help quantify ecosystem services in support of restoration.

关键词： Decision support Ecosystem services Forest restoration Modeling Valuation Comparative toolsassessment

Modelling internal air systems ingas turbine engines

在线全文

学校读者我要写书评

暂无评论

航空动力学报 2007年第4期22卷 505-520页

作者： j.michael Owen Department of Mechanical Engineering University of Bath

Rotating-disc systems can be used to model,experimentally and computationally,the flow and heat transfer that occur inside the internal cooling-air systems of gas turbine *** rotating-disc systems have been used successfully to simplify and understand some of the complex flows that occur in internal-air systems,and designers have used this insight to improve the cooling effectiveness,thereby increasing the engine efficiency and reducing the *** this review paper,three important cases are considered:hot-gas ingress;the pre-swirl system;and buoyancy-induced ***,or ingestion,occurs when hot gas from the mainstream gas path is ingested into the wheel-space between the turbine disc and its adj.cent *** seals are fitted at the periphery of the system,and sealing flow is used to reduce or prevent ***,too much sealing air reduces the engine efficiency,and too little can cause serious overheating,resulting in damage to the turbine rim and blade *** the flow is three-dimensional and unsteady,there are encouraging signs that simple ‘orifice models’ could be used to estimate the amount of ingress into the *** a pre-swirl system,the cooling air for the gas-turbine blades is swirled by stationary nozzles,and the air is delivered to the blades via receiver holes in the rotating turbine *** the air reduces its temperature relative to the rotating blades,and the designer needs to calculate the air temperature and pressure drop in the *** designer also needs to calculate the effect of this swirling flow on the heat transfer from the turbine disc to the air,as this has a significant effect on the temperature distribution and stresses in the *** experimental and computational studies have given a better understanding of the flow and heat transfer in these ***-induced flow occurs in the cavity between two co-rotating compressor discs when the temperature of the discs is higher than

关键词：燃气涡轮机车空气动力学数学模型旋转式圆盘系统

Numerical investigation of the ultimate lateral resistance of piles in soft clay

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2014年第2期8卷 194-200页

作者： Konstantinos P. TZIVAKOS michael j. KAVVADAS School of Civil Engineering Geotechbical Department National Technical University of Athens (NTUA) Athens 15780 Greece

The paper presents a numerical study on the undrained lateral response of a single, free-head, reinforced concrete pile in soft clays. Soil conditions simulating normally consolidated clays are examined undrained shear strength increasing with depth--and the pile-soil interaction under static lateral loading is analyzed. The nonlinear p-y curves proposed in literature for soft clays are imported into a beam-on-nonlinear-Winkler-foundation simulation in order to predict the pile head lateral load--displacement curve and the distribution of the horizontal displacement and bending moment along the pile. The striking differences among these methods require further investigation via 3D finite element analyses. The determination of the ultimate soil resistance Pult from the results of the finite element analyses aims at providing the estimation of a range of values for the ultimate soil resistance coefficient Np with depth and the comparison of the derived values to the corresponding ones proposed by existing methodologies.

关键词： laterally loaded pile soft clay p-y curves finite element method (FEM)

Integrating flood depth and plant resistance with chlorantraniliprole seed treatments for management of rice water weevil, Lissorhoptrus oryzophilus （Coleoptera： Curculionidae）

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2015年第5期22卷 679-687页

作者： Srinivas K. Lanka David C. Blouin michael j. Stout Department of Entomology Louisiana State University Agricultural Center Baton Rouge LA 70803 USA

Chlorantraniliprole seed treatments in rice provide effective suppression of rice water weevil populations in the United States; however, heavy reliance on prophylac- tic insecticide treatments as a sole strategy could destabilize management programs for this insect. The present research evaluated the compatibility of seed treatments with two other potential management tactics--plant resistance and shallow flooding-by conducting two split-plot experiments in 2009 and 2011. In both experiments, no substantial antago- nism was found among the 3 different tactics. Statistical interactions in these experiments arose from the strong and persistent effects of chlorantraniliprole on larval densities rather than incompatibility of tactics. In 2009, weevil densities differed among varieties and were significantly lower on the cultivar ＂j.fferson.＂ In 2011, weevil densities were reduced sig- nificantly in shallow-flooded plots compared to deep-flooded plots. Significant reductions in weevil numbers by chlorantraniliprole seed treatments, even at application rates 5 fold lower than commercially recommended rates, demonstrated the potential to reduce appli- cation rates of this highly potent larvicide. These latter results suggest that future studies on the relationship between chlorantraniliprole seed treatment rate and weevil fitness are warranted.

关键词： chlorantraniliprole compatibility integrated management plant resistance rice water weevil seed treatments

Semiconducting Carbon Nanotube/Fullerene Blended Heteroj.nctions for Photovoltaic Near-Infrared Photon Harvesting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2011年第11期4卷 1174-1179页

作者： Dominick j. Bindl Adam S. Brewer michael S. Arnold 1509 University Ave. Materials Science and Engineering Dept. University of Wisconsin-Madison Madison WI 53706 USA

We demonstrate that the near-infrared （NIR） absorptivity of semiconducfing single-walled carbon nanotubes （s-SWCNTs） can be harnessed in blended heteroj.nctions with the fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester （PCBM）. Photogenerated charge separation is efficiently driven by the ultrahigh interracial area of the blends and the favorable energy offsets between the two materials. NIR-sensitive photovoltaic and photodetector devices utilizing the stack （indium tin oxide/ca. 10 nm s-SWCNT：PCBM/100 nm Cj.0 nm 2,9- dimethyl-4,7-diphenyl-],10-phenanthroline （BCP）/Ag） were fabricated with NIR power conversion efficiencies 〉1.3% and peak, zero bias external quantum efficiency of 18% at λ = 1205 nm.

关键词： Carbon nanotube bulk heteroj.nction photovoltaic photodetector near-infrared (NIR)