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Proposed graphene nanospaser

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Light(science & Applications) 2014年第1期3卷 141-146页

作者： Vadym Apalkov mark i stockman Department of Physics and Astronomy Georgia State UniversityAtlantaGA 30303USA Faculty of Physics Ludwig Maximilian UniversityD-80539 MunichGermany Max Plank institute for Quantum Optics D-85748 GarchingGermany

We propose a novel nanospaser that operates in the mid-infrared region and utilizes a nanopatch of graphene as its plasmonic core and a quantum-well cascade as its gain *** design takes advantage of the low optical losses in graphene resulting from its high electron *** proposed quantum cascade graphene spaser generates optical fields with unprecedentedly high nanolocalization,which is characteristic of graphene *** spaser will be an efficient nanosource of intense and coherent hot-spot fields in the mid-infrared spectral region with potential widespread applications in mid-infrared nanoscopy,nanospectroscopy,nanolithography,and optoelectronic information processing.

关键词： graphene quantum cascade laser quantum well spaser

The relationship between intraspecific assortative mating and reproductive isolation between divergent populations

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Current Zoology 2012年第3期58卷 484-492页

作者： Daniel i. BOLNiCK mark KiRKPATRiCK Howard Hughes Medical institute and section of integrative Biology One University Station C0930 University of Texas at Austin Austin TX 78712 USA section of integrative Biology One University Station C0930 University of Texas at Austin Austin TX 78712 USA

The term ＇assortative mating＇ has been applied to describe two very different phenomena：（1） the tendency for indi- viduals to choose phenotypically similar mates from among conspecifics; or （2） the tendency to prefer conspecific over hete- rospecific mates （behavioral reproductive isolation）. Both forms of assortative mating are widespread in nature, but the relation- ship between these behaviors remains unclear. Namely, it is plausible that a preference for phenotypically similar conspecifics in cidentally reduces the probability of mating with phenotypically divergent heterospecifics. We present a model to calculate how the level of reproductive isolation depends on intraspecific assortative mating and the phenotypic divergence between species. For empirically reasonable levels of intraspecific assortment on a single trait axis, we show that strong reproductive isolation requires very substantial phenotypic divergence. We illustrate this point by applying our model to empirical data from threespine stickleback Gasterosteus aculeatus and Darwin＇s Finches （Geospiza spp）. We conclude that typical levels of intraspecific assortment cannot generally be extrapolated to explain levels of interspecific reproductive isolation. instead, reproductive isolation between species likely arises from different mate choice behaviors, or multivariate assortative mating [Current Zoology 58 （3）： 484-492, 2012].

关键词： Assortative mating Hybridization Mating preference Reproductive isolation speciation

Assessing support alternatives for longwall gateroads subject to changing stress

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international Journal of Mining science and Technology 2021年第1期31卷 103-110页

作者： Gabriel s.Esterhuizen i.Berk Tulu Dave F.Gearhart Heather Dougherty mark Van Dyke National institute for Occupational safety and Health Pittsburgh Mining Research DivisionPittsburghPA 15236USA West Virginia University MorgantownWV 26506USA

Longwall gateroad entries are subject to changing horizontal and vertical stress induced by redistribution of loads around the extracted *** stress changes can result in significant deformation of the entries that may include roof sag,rib dilation,and floor *** operators install different types of supports to control the ground response and maintain safe access and ventilation of the longwall *** paper describes recent research aimed at quantifying the effect of longwall-induced stress changes on ground stability and using the information to assess support *** research included monitoring of ground and support interaction at several operating longwall mines in the U.s.,analysis and calibration of numerical models that adequately represent the bedded rock mass,and observation of the support systems and their response to changes in *** models were then used to investigate the impact of geology and stress conditions on ground deformation and support response for various depths of cover and geologic *** research results were summarized in two regression equations that can be used to estimate the likely roof deformation and height of roof yield due to longwall-induced stress *** information is then used to assess the ability of support systems to maintain the stability of the *** application of the method is demonstrated with a retrospective analysis of the support performance at an operating longwall mine that experienced a headgate roof *** method is shown to produce realistic estimates of gateroad entry stability and support performance,allowing alternative support systems to be assessed during the design and planning stage of longwall operations.

关键词： Longwall Gateroad support design Coal standing support

introduction to Management science A Modeling and Case studies Approach with spreadsheets Frederick s. Hillier, mark s. Hillier 2nd ed.

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Calibration of coupled hydro-mechanical properties of grain-based model for simulating fracture process and associated pore pressure evolution in excavation damage zone around deep tunnels

丛书名： McGraw-Hill/irwin series Operations and decision sciences

2003年

作者： Frederick s. Hillier mark s. Hillier

includes index.

ISBN: (数字)0072493682

ISBN: (纸本)0072493682

includes index.

关键词： Management science.

来源：畅想之星图书光盘版（南... 评论

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第1期13卷 60-83页

作者： Kiarash Farahmand mark s.Diederichs Department of Geological sciences and Geological Engineering Queen’s UniversityKingstonOntarioK7L 3N6Canada Golder Associates VancouverBritish ColumbiaCanada

The objective of this paper is to develop a methodology for calibration of a discrete element grain-based model(GBM)to replicate the hydro-mechanical properties of a brittle rock measured in the laboratory,and to apply the calibrated model to simulating the formation of excavation damage zone(EDZ)around underground ***,a new cohesive crack model is implemented into the universal distinct element code(UDEC)to control the fracturing behaviour of materials under various loading ***,a methodology for calibration of the components of the UDEC-Voronoi model is *** role of connectivity of induced microcracks on increasing the permeability of laboratory-scale samples is *** calibrated samples are used to investigate the influence of pore fluid pressure on weakening the drained strength of the laboratory-scale *** validity of the Terzaghi’s effective stress law for the drained peak strength of low-porosity rock is tested by performing a series of biaxial compression test ***,the evolution of damage and pore pressure around two unsupported circular tunnels in crystalline granitic rock is studied.

关键词： Coupled hydro-mechanical properties Excavation damage zone(EDZ) Grain-based model(GBM)calibration stress-fracturing of rock Cohesive crack model stress-dependent permeability

influence of dissolved organic matter character on mercury incorporation by planktonic organisms: An experimental study using oligotrophic water from Patagonian lakes

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Journal of Environmental sciences 2013年第10期25卷 1980-1991页

作者： María C.Diéguez Claudia P.Queimalios sergio Ribeiro Guevara mark Marvin-DiPasquale Carolina soto Crdenas María A.Arribre Laboratorio de Fotobiología INIBIOMA CONICET-UNComahue Laboratorio de Fotobiolog INIBIOMA CONICET-UNComahue Laboratorio de Anlisis por Activación Neutrónica Centro Atómico Bariloche CNEA United states Geological survey Laboratorio de Anlisis por Activacio Neutrónica Centro Atómico Bariloche CNEA

Ligands present in dissolved organic matter （DOM） form complexes with inorganic divalent mercury （Hg^2＋） affecting its bioavailability in pelagic food webs. This investigation addresses the influence of a natural gradient of DOM present in Patagonian lakes on the bioaccumulation of Hg^2＋（the prevailing mercury species in the water column of these lakes） by the algae Cryptomonas erosa and the zooplankters Brachionus calyciflorus and Boeckella antiqua. Hg^2＋ accumulation was studied through laboratory experiments using natural water of four oligotrophic Patagonian lakes amended with^197Hg^2＋. The bioavailability of Hg^2＋ was affected by the concentration and character of DOM. The entrance of Hg^2＋ into pelagic food webs occurs mostly through passive and active accumulation. The incorporation of Hg^2＋ by Cryptomonas, up to 27% of the Hg^2＋ amended, was found to be rapid and dominated by passive adsorption, and was greatest when low molecular weight compounds with protein-like or small phenolic signatures prevailed in the DOM. Conversely, high molecular weight compounds with a humic or fulvic signature kept Hg^2＋ in the dissolved phase, resulting in the lowest Hg^2＋ accumulation in this algae. in Brachionus and Boeckella the direct incorporation of Hg from the aqueous phase was up to 3% of the Hg^2＋ amended. The dietary incorporation of Hg^2＋ by Boeckella exceeded the direct absorption of this metal in natural water, and was remarkably similar to the Hg^2＋ adsorbed in their prey. Overall, DOM concentration and character affected the adsorption of Hg^2＋ by algae through competitive binding, while the incorporation of Hg^2＋ into the zooplankton was dominated by trophic or dietary transfer.

关键词： mercury dissolved organic matter plankton mercury incorporation Patagonian lakes Argentina

An assessment of interspecific competition between two introduced parasitoids of Diaphorina citri (Hemiptera: Liviidae)on caged citrus plants

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insect science 2019年第1期26卷 119-127页

作者： Meghan A.Vankosky mark s.Hoddle Department of Entomology University of CalifomiaRiversideCalifomiaUSA Center for invasive species Research University of CaliforniaRiversideCaliforniaUSA

Two parasitoids attacking nymphs of Asian citrus psyllid,Diaphorina citri Kuwayama (Hemiptera:Liviidae),Tamarixia radiata (Waterston)(Hymenoptera:Eulophi- dae)and Diaphoreneyrtus aligarhensis (shafee,Alam &Agarwal)(Hymenoptera:Encyrtidae)are being released in California,UsA in a classical biological control program. To evaluate the effect of multiple parasitoid species on *** mortality,we conducted mesocosm experiments under controlled conditions using a complete block design with 6 treatments (*** nymphs exposed to:no parasitoids;*** or *** alone;*** or *** released first (by 48 h);and both species released simultaneously).Parasitism of *** nymphs by *** exceeded 60%and was unchanged when *** were *** by *** was greatest when T. radiata was absent (-28%)and was reduced in all treatments with *** present (ity and parasitoid-related mortality *** was consistent across parasitoid *** results suggest that competition between *** and *** is asymmetric and favors *** may be difficult for *** to contribute significantly to *** biological control where *** is ***, results reported here suggest that competition between *** and *** is not likely to reduce parasitism by *** or reduce parasitoid-induced mortality of ***.

关键词： Asian citrus psyllid classical biological control competition Diaphorencyrtus aligarhensis Tamarixia radiata

Assessment of strain bursting in deep tunnelling by using the finite-discrete element method

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第1期11卷 12-37页

作者： ioannis Vazaios mark s.Diederichs Nicholas Vlachopoulos Department of Ceological saences and Ceological Engineering Queen's UniversityKingstonCanada

Rockbursting in deep tunnelling is a complex phenomenon posing significant challenges both at the design and construction stages of an underground excavation within hard rock masses and under high in situ stresses. While local experience, field monitoring, and informed data-rich analysis are some of the tools commonly used to manage the hazards and the associated risks, advanced numerical techniques based on discontinuum modelling have also shown potential in assisting in the assessment of rockbursting. in this study, the hybrid finite-discrete element method(FDEM) is employed to investigate the failure and fracturing processes, and the mechanisms of energy storage and rapid release resulting in bursting, as well as to assess its utility as part of the design process of underground *** the calibration of the numerical model to simulate a deep excavation in a hard, massive rock mass, discrete fracture network(DFN) geometries are integrated into the model in order to examine the impact of rock structure on rockbursting under high in situ stresses. The obtained analysis results not only highlight the importance of explicitly simulating pre-existing joints within the model, as they affect the mobilised failure mechanisms and the intensity of strain bursting phenomena, but also show how the employed joint network geometry, the field stress conditions, and their interaction influence the extent and depth of the excavation induced damage. Furthermore, a rigorous analysis of the mass and velocity of the ejected rock blocks and comparison of the obtained data with well-established semi-empirical approaches demonstrate the potential of the method to provide realistic estimates of the kinetic energy released during bursting for determining the energy support demand.

关键词： Rockburst Finite-discrete element method(FDEM) Deep tunnelling Hard rock excavations Brittle fracturing Discrete fracture network(DFN)

salicaceae detoxification abilities in Florida tiger swallowtail butterflies （Papilio glaucus maynardi Gauthier）＂ Novel ability or Pleistocene holdover？

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insect science 2012年第3期19卷 337-345页

作者： Matthew s. Lehnert J. mark scriber McGuire Center for Lepidoptera and Biodiversity Florida Museum of Natural History University of Florida Gainesville Florida Department of Entomology Soils and Plant Sciences Clemson University Clemson South Carolina Department of Entomology Michigan State University East Lansing Michigan USA

Florida populations of the eastern tiger swallowtail butterfly, Papilio glaucus L., have unique morphological features and ecological adaptations that have contributed to their subspecies status （P. g. rnaynardi Gauthier）. We describe geographically unique abilities for detoxification of Carolina willow, salix caroliniana Michx. （salicaceae）, for several Florida populations of P. g. maynardi. Of all the approximately 570 worldwide species of the Papilionidae, such salicaceae detoxification abilities exist only in the allopatric North American western and northernmost species （P. rutulus Lucas, R eurymedon Lucas and P. canadensis Rothschild ＆ Jordan）. Females of P. glaucus collected from populations in southeastern UsA were examined for oviposition preference in 5-choice assays, and displayed a low preference for salicaceae （〈5%）, but larvae from Florida populations exhibited a high survival （〉 60%） on these plants. Detoxification abilities have previously shown to be autosomally inherited, and can be transferred via natural or hand-paired interspecific hybrid introgression. However, these Florida populations are at least 700-1 500 km from the nearest hybrids or the hybrid species, 17. appalachiensis Pavulaan ＆ Wright, which possess these detoxification abilities. in any case, the Z （ = X）-linked oviposition preferences for salicaceae are lacking in these Florida populations, illustrating genetic independence ofoviposition preference determination and larval survival/performance abilities. The origins of detoxification abilities are unlikely to be due to recent climate-driven introgression, and may represent ancestral trait carry-overs from interglacial refugium populations of the Pleistocene epoch.

关键词： eastern tiger swallowtail genetic introgression interglacial island refugia,Papilio glaucus maynardi Papilionidae host plants salicaceae detoxification