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Delayed juvenile behavioral development and prolonged dependence are adaptations to desert life in the grey falcon

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Current Zoology 2022年第6期68卷 679-687页

作者： jonny SCHOeNJAHN Chris R.PAVeY Gimme H.WAlTeR School of Biological Sciences The University of QueenslandBrisbaneQLD 4072Australia CSIRO land and Water DarwinNT 0822Australia

Rapid learning in the young of most endothermic animals can be expected to be favored by natural selection because early independence reduces the period of *** of comparatively slow juvenile development continue,therefore,to attract scientific *** most species of birds,including raptors,the young depend on their parents for some time after fledging for the provisioning of food and for protection while they learn to become nutritionally and otherwise *** raptors,post-fledging dependence periods that exceed 6 months are exclusive to the largest species and these have reproductive cycles that exceed 12 *** contrast,young of the medium-sized grey falcon Falco hypoleucos have been reported in close company with their parents up to 12 months after fledging,that is,at a time when the adults are expected to breed *** investigated the occurrence and characteristics of prolonged adult–juvenile association relative to other falcons and similar-sized *** found that the behavioral development of grey falcon young is extremely delayed,and that they even depend nutritionally on their parents for up to 12 months after *** suggest that these 2 distinctive features are,ultimately,adaptations of the grey falcon to its extreme environment,Australia’s arid and semi-arid zone,one of the hottest environments in the world.

关键词： arid environment behavioral adaptation bird of prey post-fledging period

Numerical manifold method modeling of coupled processes in fractured geological media at multiple scales

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Journal of Rock Mechanics and Geotechnical engineering 2020年第4期12卷 667-681页

作者： Mengsu Hu jonny Rutqvist lawrence Berkeley National laboratory BerkeleyCA94720USA

The greatest challenges of rigorously modeling coupled hydro-mechanical(HM)processes in fractured geological media at different scales are associated with computational *** challenges include dynamic shearing and opening of intersecting fractures at discrete fracture scales as a result of coupled processes,and contact alteration along rough fracture surfaces that triggers structural and physical changes of fractures at micro-asperity *** this paper,these challenges are tackled by developing a comprehensive modeling approach for coupled processes in fractured geological media based on numerical manifold method(NMM)at multiple *** on their distinct geometric features,fractures are categorized into three different scales:dominant fracture,discrete fracture,and discontinuum asperity *** the scale is relative,that of the fracture relative to that of the research interest or *** geometric representations of fractures at different scales are used,and different governing equations and constitutive relationships are *** dominant fractures,a finite thickness zone model is developed to treat a fracture as a porous nonlinear *** fracture mechanical behavior is accurately modeled with an implicit approach based on strain *** discrete fractures,a zero-dimensional model was developed for analyzing fluid flow and mechanics in fractures that are geometrically treated as boundaries of the rock *** the zero-dimensional model,these fractures can be modeled with arbitrary orientations and *** can be fluid conduits or seals,and can be open,bonded or *** the discontinuum asperity scale,the geometry of rough fracture surfaces is explicitly represented and contacts involving dynamic alteration of contacts among asperities are rigorously *** this approach,fracture alteration caused by deformation,re-arrangement and sliding of rough surfaces can be *** comprehensive m

关键词： Dominant fractures Discrete fractures Discontinuum asperity scale Coupled processes Numerical manifold method(NMM)

Proto-South China Sea Plate Tectonics Using Subducted Slab Constraints from Tomography

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Journal of earth Science 2018年第6期29卷 1304-1318页

作者： jonny Wu John Suppe Department of earth and Atmospheric Sciences University of Houston

The past size and location of the hypothesized proto-South China Sea vanished ocean basin has important plate-tectonic implications for Southeast Asia since the Mesozoic. Here we present new details on proto-South China Sea paleogeography using mapped and unfolded slabs from tomography. Mapped slabs included： the eurasia-South China Sea slab subducting at the Manila trench; the northern Philippine Sea Plate slab subducting at the Ryukyu trench; and, a swath of detached, subhorizontal, slab-like tomographic anomalies directly under the South China Sea at 450 to 700 km depths that we show is subducted ‘northern proto-South China Sea’ lithosphere. Slab unfolding revealed that the South China Sea lay directly above the ‘northern Proto-South China Sea’ with both extending 400 to 500 km to the east of the present Manila trench prior to subduction. Our slab-based plate reconstruction indicated the proto-South China Sea was consumed by double-sided subduction, as follows：（1） The ‘northern proto-South China Sea’ subducted in the Oligo–Miocene under the Dangerous Grounds and southward expanding South China Sea by in-place ‘self subduction’ similar to the western Mediterranean basins;（2） limited southward subduction of the proto-South China Sea under Borneo occurred pre-Oligocene, represented by the 800–900 km deep ‘southern proto-South China Sea’ slab.

关键词： seismic tomography plate tectonics South China Sea proto-South China Sea subducted slabs Borneo Oligocene–Miocene

Influence of hysteretic stress path behavior on seal integrity during gas storage operation in a depleted reservoir

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Journal of Rock Mechanics and Geotechnical engineering 2020年第4期12卷 886-899页

作者： Pierre Jeanne Yingqi Zhang jonny Rutqvist lawrence Berkeley National laboratory Energy Geosciences DivisionBerkeleyCA94720USA

In this study,we numerically investigate the influence of hysteretic stress path behavior on the seal integrity during underground gas storage operations in a depleted *** study area is the Honor Rancho Underground Storage Facility in los Angeles County(California,USA),which was converted into an underground gas storage facility in 1975 after 20 years of oil and gas *** our simulations,the geomechanical behavior of the sand reservoir is modeled using two models:(1)a linear elastic model(non-hysteretic stress path)that does not take into consideration irreversible deformation,and(2)a plastic cap mechanical model which considers changes in rock elastic properties due to irreversible deformations caused by plastic reservoir compaction(hysteretic stress path).It shows that the irreversible compaction of the geological layer over geologic time and during the reservoir depletion can have important consequences on stress tensor orientation and *** depletion-induced irreversible compaction can lead to an over-estimation of the calculation of the maximum working reservoir ***,this irreversible compaction may bring the nearby faults closer to ***,regardless of the two models applied,the geomechanical analysis shows that for the estimated stress conditions applied in this study,the Honor Rancho Underground Storage Facility is being safely operated at pressures much below what would be required to compromise the seal integrity.

关键词： Gas storage Stress path Geomechanical simulation Caprock integrity Fault stability Modified cam-clay model Honor rancho underground storage facility

Intermingled fates of the South China Sea and Philippine Sea plate

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National Science Review 2019年第5期6卷 886-890页

作者： Minghui Zhao Jean-Claude Sibuet jonny Wu Key laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of Sciences Innovation Academy of South China Sea ecology and environmental engineering Chinese Academy of Sciences Department of earth and Atmospheric Sciences University of Houston

Recent studies have shown the extent and nature of the South China Sea (SCS) at the end of spreading by unfolding (*** restoring) the Manila slab,which is the subducted part of the SCS,and by identifying the nature of... 详细信息

关键词： SCS domain Intermingled fates of the South China Sea and Philippine Sea plate China

In-situ SeM observation on fracture behavior of austempered silicon alloyed steel

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China Foundry 2009年第3期6卷 185-190页

作者： Vuorinen esa Grahn jonny Division of engineering Materials Department of Applied Physics and Mechanical EngineeringLule University of Technology

Crack initiation, propagation and microfracture processes of austempered high silicon cast steel have been investigated by using an in-situ tensile stage installed inside a scanning electron microscope chamber. It is revealed that micro cracks always nucleate at the yielding near imperfections and the boundary of matrix-inclusions due to the stress concentration. There are four types of crack propagations in the matrix: crack propagates along the boundary of two clusters of bainitic ferrite; crack propagates along the boundary of ferrite-austenite in bainitic ferrite laths; crack propagates into bainitic ferrite laths; crack nucleates and propagates in the high carbon brittle plate shape martensite which is transformed from some blocky retained austenite due to plastic deformation. Based on the observation and analysis of microfracture processes, a schematic diagram of the crack nucleation and propagation process of high silicon cast steel is proposed.

关键词： high silicon cast steel bainitic ferrite austempering in-situ SeM observation fracture

Mesh generation and optimization from digital rock fractures based on neural style transfer

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Journal of Rock Mechanics and Geotechnical engineering 2021年第4期13卷 912-919页

作者： Mengsu Hu jonny Rutqvist Carl I.Steefel energy Geosciences Division Lawrence Berkeley National LaboratoryBerkeleyCA94720USA

The complex geometric features of subsurface fractures at different scales makes mesh generation challenging and/or *** this paper,we make use of neural style transfer(NST),a machine learning technique,to generate mesh from rock fracture *** this new approach,we use digital rock fractures at multiple scales that represent’content’and define uniformly shaped and sized triangles to represent’style’.The 19-layer convolutional neural network(CNN)learns the content from the rock image,including lower-level features(such as edges and corners)and higher-level features(such as rock,fractures,or other mineral fillings),and learns the style from the triangular *** optimizing the cost function to achieve approximation to represent both the content and the style,numerical meshes can be generated and *** utilize the NST to generate meshes for rough fractures with asperities formed in rock,a network of fractures embedded in rock,and a sand aggregate with multiple *** on the examples,we show that this new NST technique can make mesh generation and optimization much more efficient by achieving a good balance between the density of the mesh and the presentation of the geometric ***,we discuss future applications of this approach and perspectives of applying machine learning to bridge the gaps between numerical modeling and experiments.

关键词： Convolutional neural network(CNN) Neural style transfer(NST) Digital rock Discrete fractures Discontinuum asperities Grain aggregates Mesh generation and optimization

Interactive roles of geometrical distribution and geomechanical deformation of fracture networks in fluid flow through fractured geological media

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Journal of Rock Mechanics and Geotechnical engineering 2020年第4期12卷 780-792页

作者： Qinghua lei Xiaoguang Wang Ki-Bok Min jonny Rutqvist Department of earth Sciences ETH ZürichZürichSwitzerland laboratoire HydroSciences Montpellier Universite de MontpellierMontpellierFrance Department of energy Systems engineering Seoul National UniversitySeoulRepublic of Korea energy Geosciences Division Lawrence Berkeley National LaboratoryBerkeleyUSA

In this study,the combined effects of geometrical distribution and geomechanical deformation of fracture networks on fluid flow through fractured geological media are investigated *** consider a finite-sized model domain in which the geometry of fracture systems follows a power-law length *** geomechanical response of the fractured rock is simulated using a hybrid finitediscrete element model,which can capture the deformation of intact rocks,the interaction of matrix blocks,the displacement of discrete fractures and the propagation of new *** far-field stress loading,the locally variable stress distribution in the fractured rock leads to a stress-dependent variable aperture field controlled by compression-induced closure and shear-induced dilatancy of rough *** equivalent permeability of the deformed fractured rock is calculated by solving for the fracture-matrix flow considering the cubic relationship between fracture aperture and flow rate at each local fracture *** report that the geometrical connectivity of fracture networks plays a critical role in the hydromechanical processes in fractured rocks.A well-connected fracture system under a high stress ratio condition exhibits intense frictional sliding and large fracture dilation/opening,leading to greater rock mass ***,a disconnected fracture network accommodates much less fracture shearing and opening,and has much lower bulk *** further propose an analytical solution for the relationship between the equivalent permeability of fractured rocks and the connectivity metric(*** parameter)of fracture networks,which yields an excellent match to the numerical *** infer that fluid flow through a well-connected system is governed by traversing channels(forming an“in parallel”architecture)and thus equivalent permeability is sensitive to stress loading(due to stress-dependent fracture permeability),whilst fluid flow through a discon

关键词： Fracture Stress Aperture Connectivity Permeability

linked multicontinuum and crack tensor approach for modeling of coupled geomechanics, fluid flow and transport in fractured rock

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Journal of Rock Mechanics and Geotechnical engineering 2013年第1期5卷 18-31页

作者： jonny Rutqvist Colin leung Andrew Hoch Yuan Wang Zhen Wang lawrence Berkeley National laboratory (lBNl) Imperial College Serco energy Hohai University Tongji University

In this paper, we present a linked multicontinuum and crack tensor approach for modeling of coupled geomechanics, fluid flow, and solute transport in fractured rock. We used the crack tensor approach to calculate effective block-scale properties, including anisotropic permeability and elastic tensors, as well as multicontinuum properties relevant to fracture-matrix interactions and matrix diffusion. In the mod- eling, we considered stress dependent properties, through stress-induced changes in fracture apertures, to update permeability and elastic tensors. We evaluated the effectiveness and accuracy of our multicon- tinuum approach by comparing our modeling results with that of three independent discrete fracture network （DFN） models. In two of the three alternative DFN models, solute transport was simulated by particle tracking, an approach very different from the standard solute transport used in our multicon- tinuum modeling. We compared the results for flow and solute transport through a 20 m x 20 m model domain of fractured rock, including detailed comparison of total flow rate, its distribution, and solute breakthrough curves. In our modeling, we divided the 20 m ~ 20 m model domain into regular blocks, or continuum elements. We selected a model discretization of 40 x 40 elements （having a side length of 0.5 m） that resulted in a fluid-flow rate equivalent to that of the DFN models. Our simulation results were in reasonably good agreement with the alternative DFN models, for both advective dominated transport （under high hydraulic gradient） and matrix-diffusion retarded transport （under low hydraulic gradient）. However, we found pronounced numerical dispersion when using larger grid blocks, a problem that could be remediated by the use of a finer numerical grid resolution, while maintaining a larger grid for evalua- tion of equivalent properties, i.e. a property grid overlapping the numerical grid. Finally, we encountered some difficulties in using our approac

关键词： Fractured rockModelingFluid flowStressMulticontinuumCrack tensor