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Nonlinear aspects of energy dissipation in wood-panel joints sara Casciati

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Earthquake Engineering and Engineering Vibration 2007年第4期6卷 259-268页

作者： sara Casciati AsTRA Dept. School of Architecture University of Catania at Siracusa 96100 Siracusa Italy

The joints connecting vertical and horizontal elements are the ＂weak link＂ in structural systems assembled from wood panels. If they are too weak, local failures may occur, resulting in performance that is significantly below expectations. If they are too resistant, the joints may be unable to dissipate energy during vibrations, thus possibly initiating a fast progressive failure. This paper re-processes and re-elaborates the results of shaking table tests previously carried out by the author and other co-workers. The goal is to assess the feasibility of a joint which is able to dissipate energy during vibration, without degrading the connection performance.

关键词： dynamic excitation energy dissipation wood panels joint monitoring system shaking table tests

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Efficient photon coupling from a diamond nitrogen vacancy center by integration with silica fiber

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Light(science & Applications) 2016年第1期5卷 671-676页

作者： Rishi N Patel tim.schröder Noel Wan Luozhou Li sara L Mouradian Edward H Chen Dirk R Englund Department of Electrical Engineering and Computer science Massachusetts Institute of Technology77 Massachusetts AveCambridgeMA 02139USA Department of Applied Physics Stanford University348 Via Pueblo MallStanfordCA 94305USA

A central goal in quantum information science is to efficiently interface photons with single optical modes for quantum networking and distributed quantum ***,we introduce and experimentally demonstrate a compact and efficient method for the low-loss coupling of a solid-state qubit,the nitrogen vacancy(NV)center in diamond,with a single-mode optical *** this approach,single-mode tapered diamond waveguides containing exactly one high quality NV memory are selected and integrated on tapered silica *** optimization of an adiabatic coupler indicates that near-unity-efficiency photon transfer is possible between the two ***,we find an overall collection efficiency between 16%and 37%and estimate a single photon count rate at saturation above 700 *** integrated system enables robust,alignment-free,and efficient interfacing of single-mode optical fibers with single photon emitters and quantum memories in solids.

关键词： diamond nanophotonics fiber optics nitrogen vacancy center quantum optics single photon source

Automatic characterization of spherical metal powders by microscope image analysis:a parallel computing approach

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Journal of Iron and steel Research International 2023年第11期30卷 2293-2300页

作者： Xiang Li Linyi Cui sara shonkwiler sara McMains University of California BerkeleyBerkeleyCA94720USA The Hong Kong Polytechnic University Hong KongChina

The microstructural characteristics of spherical metal powders play an important role in determining the quality of mechanical parts manufactured by powder metallurgy *** the individual powder particles from their microscopic images is one of the most convenient and cost-efficient methods for the analysis of powder *** numerous image processing algorithms have been developed for automating the powder particle identification process,they perform less accurately in identifying adjacent particles that are heavily overlapped in their image *** propose an automatic algorithm to robustly and accurately identify spherical powder particles,especially heavily overlapped particles,from their microscope images.A parallel computing framework is designed to further enhance the computational efficiency of the proposed *** characteristics such as particle size distribution and the location of potential satellite particles have been derived from our identification *** accuracy and efficiency of our algorithm are validated by real-world scanning electron microscope images,outperforming other existing methods and achieving both precision and recall above 99%.

关键词： computing image overlapped

Geological Controls and Prospectivity Mapping for Manganese Ore Deposits Using Predictive Modeling Comparison:An Integration of Outcrop and Remote sensing Data,sinai Microplate,Egypt

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Journal of Earth science 2023年第2期34卷 588-608页

作者： sara Zamzam Geology Department Faculty of ScienceZagazig UniversityZagazig 44519Egypt

One of the most controversial minerals in their origin and occurrence around the world is manganese *** Abu Zenima area is rated one of the most economically important places where manganese ore deposits(Mn ODs)are located in the southwest sinai microplate,*** deposits are confined with the Um Bogma Formation(UBF)and the reserves of this region are relatively *** this study,optical and radar data are used in a new challenge as an attempt to reach the closest controls and setting of Mn ***,Frequency Ratio(FR)and Logistic Regression(LogR)predictive models are applied to integrate different geospatial thematic maps,to predict new potential resource zones for increasing the ranges of mining ***8 OLI,sentinel-2A Multi spectral Instrument and Radar(sentinel-1B)data are combined for mapping Mn ODs locations and their relationship with geological structures and the surrounding *** ratio,Principal and Independent Component Analysis techniques and four classification algorithms were implemented to the optical’VNIR and sWIR ***,the interferometric processing steps for sentinel-1 data were made for understanding the tectonic features in the *** FR and LogR models are validated during fieldwork with known Mn ODs *** indicate that processed images are capable of differentiation of UBF which broadly distributed in the central and southern parts of the *** ODs possibly formed by thermal events that attributed to paleo-volcanic events before the rift *** high accuracy of LogR model(0.902)suggests that high Mn ODs potential zones are identified within the intersected fault zones near granitic *** integration is recommended for discriminating hydrothermally Mn ODs in other arid geographic regions.

关键词： manganese deposits Abu Zenima Landsat8 oli sentinel data fault zones predictive modeling remote sensing

False codling moth Thaumatotibia leucotreta （Lepidoptera, Tortricidae） larvae are chill-susceptible

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Insect science 2012年第3期19卷 315-328页

作者： Leigh Boardman tim G. Grout John s. Terblanche Department of Conservation Ecology and Entomology Faculty of Agrisciences Stellenbosch University Stellenbosch South Africa Citrus Research International Nelspruit South Africa

This study reports on the low temperature tolerance and cold hardiness of larvae of false codling moth, Thaumatotibia leucotreta. We found that larvae have mean critical thermal minima （lower limits of activity） of 6.7℃ which was influenced by feeding status. The effects of low temperature exposure and duration of exposure on larval survival were assessed and showed that the temperature at which 50% of the population survives is -11.5 ± 0.3℃ after 2 h exposure. The supercooling point （sCP, i.e., freezing temperature） was investigated using a range of cooling rates and under different conditions （feeding and hydration status） and using inoculative freezing treatments （in contact with water or orange juice）. The sCP decreased significantly from -15.6℃ to -17.4℃ after larvae were fasted for 24 h. Twenty-four hour treatments at either high or low relative humidity （95.9% or 2.4%） also significantly decreased sCP to -17.2℃ and -18.2℃ respectively. Inoculative freezing （by water contact） raised sCP from -15.6℃ to -6.8℃ which could have important implications for post-harvest sterilization. Cooling rates did not affect sCP which suggests that there is limited phenotypic plasticity of sCP during the larval life-stage, at least over the short time-scales investigated here. In conclusion, larvae of T. leucotreta are chill-susceptible and die upon freezing. These results are important in understanding this pest＇s response to temperature variation, understanding pest risk status and improving post-harvest sterilization efficacy

关键词： behavior chill injury cold hardiness disinfestations extracellular freezing,lethal limits life-stage

Effect of Baroclinicity on Vortex Axisymmetrization. Part Ⅱ:Baroclinic Basic Vortex

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Advances in Atmospheric sciences 2014年第6期31卷 1267-1278页

作者： Jiayi PENG Melinda s.PENG tim LI Eric HENDRICKs IMsG at Environmental Modeling Center NCEP/NOAA College Park Maryland USA Naval Research Laboratory Monterey California USA Department of Meteorology and IPRC University of Hawaii at Manoa Honolulu Hawaii USA

The effect of baroclinicity on vortex axisymmetrization is examined within a two-layer dynamical *** basic state vortices are constructed with varying degrees of baroclinicity：（i） barotropic,（ii） weak baroclinic,and （iii） strong *** linear and nonlinear evolution of wavenumber-2 baroclinic disturbances are examined in each of the three basic state *** results show that the radial propagating speed of the vortex Rossby wave at the lower level is larger with the stronger baroclinicity,resulting in a faster linear axisymmetrization process in the stronger baroclinic *** is found that the nonlinear axisymmetrization process takes the longest time in the strongest baroclinic vortex among the three different basic vortices due to the weaker kinetic energy transfer from asymmetric to symmetric circulations at the lower level.A major finding in this study is that the same initial asymmetric perturbation can have different effects on symmetric vortices depending on the initial vortex *** numerical weather prediction models,this implies that there exists a sensitivity of the subsequent structural and intensity change solely due to the specification of the initial vertical shear of the tropical cyclone vortex.

关键词： vortex axisymmetrization asymmetry baroclinicity

Effect of Baroclinicity on Vortex Axisymmetrization. Part Ⅰ:Barotropic Basic Vortex

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Advances in Atmospheric sciences 2014年第6期31卷 1256-1266页

作者： Melinda s.PENG Jiayi PENG tim LI Eric HENDRICKs Naval Research Laboratory Monterey California USA IMsG at Environmental Modeling Center NCEP/NOAA College Park Maryland USA Department of Meteorology and IPRC University of Hawaii at Manoa Honolulu Hawaii USA

The barotropic and baroclinic disturbances axisymmetrized by the barotropic basic vortex are examined in an idealized modeling framework consisting of two *** a Wentzel-Kramers-Brillouin approach,the radial propagation of a baroclinic disturbance is shown to be slower than a barotropic disturbance,resulting in a slower linear axisymmetrization for baroclinic *** slower-propagating baroclinic waves also cause more baroclinic asymmetric kinetic energy to be transferred directly to the barotropic symmetric vortex than from barotropic disturbances,resulting in a faster axisymmetrization process in the nonlinear baroclinic wave case than in the nonlinear barotropic wave case.

关键词： vortex axisymmetrization asymmetry baroclinicity

solvable base change and Rankin-selberg convolutions

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science China Mathematics 2017年第1期60卷 99-112页

作者： GILLEsPIE tim Department of Mathematics St. Ambrose University Davenport IA 52803 USA

Let π and π′ be unitary automorphic cuspidal representations of GL_n(A_E) and GL_m(A_F), and let E and F be solvable Galois extensions of Q of degrees ? and ?′, respectively. Using the fact that the automorphic induction and base change maps exist for E and F, and assuming an invariance condition under the actions of the Galois groups, we attach to the pair(π, π′) a Rankin-selberg L-function L(s, π×E,Fπ′) for which we prove a prime number theorem. This gives a method for comparing two representations that could be defined over completely different extensions, and the main results give a measure of how many cuspidal components the two representations π and π′ have in common when automorphically induced down to the rational numbers. The proof uses the structure of the Galois group of the composite extension EF and the character groups attached to the fields via class field theory. The second main theorem also gives an indication of when the base change of π up to the composite extension EF remains cuspidal.

关键词： automorphic L-function base change automorphic induction

Antipredator deception in terrestrial vertebrates

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Current Zoology 2014年第1期60卷 16-25页

作者： tim CARO Department of Wildlife Fish and Conservation Biology and Center of Population Biology University of California Davis CA95616 USA

Abstract Deceptive antipredator defense mechanisms fall into three categories： depriving predators of knowledge of prey＇s presence, providing cues that deceive predators about prey handling, and dishonest signaling. Deceptive defenses in terrestrial vertebrates include aspects of crypsis such as background matching and countershading, visual and acoustic Batesian mimicry, active defenses that make animals seem more difficult to handle such as increase in apparent size and threats, feigning injury and death, distractive behaviours, and aspects of flight. After reviewing these defenses, I attempt a preliminary evaluation of which aspects of antipredator deception are most widespread in amphibians, reptiles, mammals and birds

关键词： Amphibians Birds Defenses Dishonesty Mammals Prey Reptiles