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Unprecedented Retreat in a 50-Year Observational Record for Petermann Glacier, North Greenland

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Atmospheric and Oceanic Science Letters 2013年第5期6卷 259-265页

作者： Ola M. JOHANNESSEN Mohamed BABIKER martin w. MILES Nansen Environmental and Remote Sensing Center Nansen Scientific Society Nansen-Zhu International Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Uni Research AS Bjerknes Centre for Climate Research

Petermann Glacier is a marine-terminating outlet glacier that had a 70 km-long floating ice tongue prior to a ～ 270 km2 calving event that w.s observed from satellite sensors in August 2010,shortening the ice tongue by ～ 27 ***,in July 2012,another 10 km w.s lost through *** order to understand these events in perspective,here the authors perform a long-term data analysis of Petermann Glacier calving-front variability and ice velocity for each year in the 1990s-2000s,supplemented by available observations from the previous three *** major （on the order of 100 krm2） calving events are identified,w.th ～ 153 km2 calved from 1959 to 1961,～ 168 km2 in 1991,～ 71 km2 in 2001,～ 270 km2 in 2010,and ～ 130 km2 in 2012-as w.ll as ～ 31 k m2 calved in *** increased frequency of major calving events in recent years has left the front terminus position retreated nearly 25 km beyond the range of observed in previous *** contrast,stable ice-dynamics are suggested from ice-velocity measurements made each year betw.en 1993-2012,w.ich are on average 1063 m yr-1,w.th limited interannual variability and no significant trend; moreover,there is no apparent relationship betw.en ice-velocity variability and calving *** degree to w.ich the massive calving events in 2010 and 2012 represent natural episodic variability or a response to atmospheric and/or oceanic changes remains speculative; how.ver,melt-induced w.akening of the floating ice tongue in recent years is strongly suggested.

关键词： Greenland outlet glaciers iceberg calving satellite remote sensing

Tow.rd understanding Cretaceous climate An updated review

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Science China Earth Sciences 2017年第1期60卷 5-19页

作者： w.lliam w. HAY Department of Geological Sciences and University Museum University of Colorado at Boulder 2045 Windcliff Dr. Estes Park CO 80517 USA

New.data and ideas are changing our view.of conditions during the *** of the continents w.s low.r than originally thought,eliminating the'cold continental interior paradox'of fossils of plants that could not tolerate freezing occurring in regions indicated by climate models to be w.ll below.freezing in *** controversy over the height of Cretaceous sea levels has been resolved by know.edge of the effects of passage of the subducted slab of the Farallon Plate beneath the North American *** cause of shorter term sea level changes of the order of 30 to 50 meters is not because of grow.h and decay of ice sheets,but more likely the filling and release of w.ter from groundw.ter reservoirs and lakes although there may have been some ice in the Early and latest *** dioxide w.s not the only significant greenhouse gas;methane contributed significantly to the w.rmer *** of very w.rm tropical ocean temperatures(>40℃)have implications for the nature of plant life on land limited by Rubisco *** land surfaces w.re much w.tter than has been thought,w.th meandering rivers and many oxbow.lakes providing habitat for large dinosaurs.A major rethinking of the nature of conditions on a w.rmer Earth is underw.y,and a new.suite of paleoclimate simulations for the Cretaceous is needed.

关键词： Cretaceous Paleogeography Paleotopography Sea level Greenhouse Paleohydrology Paleoclimate

DEM prediction of industrial and geophysical particle flow.

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Particuology 2010年第2期8卷 106-118页

作者： Paul w. Cleary CSIRO Mathematical and Information Sciences Private Bag 33 Clayton South 3169 Australia

Simulation of industrial particle flow. using DEM （Discrete Element Method） offers the opportunity for better understanding of the flow.dynamics by the inclusion of particle scale physics that often determine the nature of these flow.. Increased understanding from the models can lead to improvements in equip- ment design and operation, potentially leading to large increases in equipment and process efficiency, throughput and]or product quality. Industrial applications are typically large and involve complex par- ticulate behaviour in complex geometries. This paper explores the critical influence of particle shape on granular system behaviour and then discusses examples of DEM applied to several large industrial problems. 2009 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. All rights reserved.

关键词： DEMGranular flow.andslideMillScreenMixing

Higher-Level Hardw.re Synthesis of the KASUMI Algorithm

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Journal of Computer Science & Technology 2007年第1期22卷 60-70页

作者： Issam w. Damaj Electrical and Computer Engineering Department Dhofar University P.O. Box 2509 Salalah 211 Oman

Programmable Logic Devices （PLDs） continue to grow.in size and currently contain several millions of gates. At the same time, research effort is going into higher-level hardw.re synthesis methodologies for reconfigurable computing that can exploit PLD technology. In this paper, w. explore the effectiveness and extend one such formal methodology in the design of massively parallel algorithms. w. take a step-w.se refinement approach to the development of correct reconfigurable hardw.re circuits from formal specifications. A functional programming notation is used for specifying algorithms and for reasoning about them. The specifications are realised through the use of a combination of function decomposition strategies, data refinement techniques, and off-the-shelf refinements based upon higher-order functions. The off-the-shelf refinements are inspired by the operators of Communicating Sequential Processes （CSP） and map easily to programs in Handel-C （a hardw.re description language）. The Handel-C descriptions are directly compiled into reconfigurable hardw.re. The practical realisation of this methodology is evidenced by a case studying the third generation mobile communication security algorithms. The investigated algorithm is the KASUMI block cipher. In this paper, w. obtain several hardw.re implementations w.th different performance characteristics by applying different refinements to the algorithm. The developed designs are compiled and tested under Celoxica＇s RC-1000 reconfigurable computer w.th its 2 million gates Virtex-E FPGA. Performance analysis and evaluation of these implementations are included.

关键词： data encryption formal models gate array methodology parallel algorithms

Convergence, stability and robustness analysis of the OFEX controller for high-speed netw.rks

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Control Theory and Technology 2016年第2期14卷 122-139页

作者： Jungang LIU Oliver w. w. YANG School of Electrical Engineering and Computer Science University of Ottawa Ottawa KI N 6N5 Canada

The OFEX （Optimal and Fully EXplicit） rate controller is able to provide not only the optimal bandw.dth allocation but also the fully explicit congestion signal to sources. It exercises link-w.se proportional fairness and netw.rk-w.se max-min fairness, w.ich enables the controller to feed the congestion signal back from the most congested link, instead of using the netw.rk- w.se proportional fairness w.ich feeds back the congestion signal summed along a flow.path. As a result, the OFEX controller overcomes the draw.acks of the relatively explicit controllers that 1） bias the multi-bottlenecked users in terms of their source sending rate and convergence speed, 2） are not adaptable to varying link bandw.dth and 3） can potentially incur large queue size upon congestion. In this paper, w. first prove that the OFEX controller can converge to its equilibrium at least as fast as a geometric series in a link. Then w. analyze the system stability w.th time delay in a single bottleneck netw.rk and show.that the OFEX controller can achieve local stability under certain conditions. Besides, the robustness analysis of the OFEX controller show. how.the dynamics of link bandw.dth may affect the revenue of a link. Finally, w.th the OPNET modeler, w. evaluate the performances of the OFEX controller and verify its effectiveness.

关键词： Fully explicit convergence stability time delay robustness performance evaluation

Inducible competitors and adaptive diversification

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Current Zoology 2013年第4期59卷 537-552页

作者： Beren w. ROBINSON David w. PFENNIG Department of Integrative Biology University of Guelph Guelph Ontario N 1G 2W 1 Canada Department of Biology University of North Carolina Chapel Hill NC 27599 USA

Identifying the causes of diversification is central to evolutionary biology. The ecological theory of adaptive diversi- fication holds that the evolution of phenotypic differences betw.en populations and species--and the formation of new.spe- cies-stems from divergent natural selection, often arising from competitive interactions. Although increasing evidence suggests that phenotypic plasticity can facilitate this process, it is not generally appreciated that competitively mediated selection often also provides ideal conditions for phenotypic plasticity to evolve in the first place. Here, w. discuss how.competition plays at least tw. key roles in adaptive diversification depending on its pattern. First, heterogenous competition initially generates heterogeneity in resource use that favors adaptive plasticity in the form of ＂inducible competitors＂. Second, once such competitively induced plas- ticity evolves, its capacity to rapidly generate phenotypic variation and expose phenotypes to alternate selective regimes allow. populations to respond readily to selection favoring diversification, as may occur w.en competition generates steady diversifying selection that permanently drives the evolutionary divergence of populations that use different resources. Thus, competition plays tw. important roles in adaptive diversification---one w.ll-know. and the other only now.emerging--mediated through its effect on the evolution ofphenotypic plasticity

关键词： Phenotypic plasticity Competition Adaptive radiation Character displacement Genetic assimilation Resourcepolymorphism

Dynamic modeling of a three-dimensional braided composite thin plate considering braiding directions

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 123-138页

作者： Chentong GAO Huiyu SUN Jianping GU w.M.HUANG College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics School of Mechanical and Aerospace Engineering Nanyang Technological University Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology School of Materials Science and EngineeringNanjing Institute of Technology

Currently, there are a limited number of dynamic models available for braided composite plates w.th large overall motions, despite the incorporation of three-dimensional(3D) braided composites into rotating blade components. In this paper, a dynamic model of 3D 4-directional braided composite thin plates considering braiding directions is established. Based on Kirchhoff's plate assumptions, the displacement variables of the plate are expressed. By incorporating the braiding directions into the constitutive equation of the braided composites, the dynamic model of the plate considering braiding directions is obtained. The effects of the speeds, braiding directions, and braided angles on the responses of the plate w.th fixed-axis rotation and translational motion, respectively, are investigated. This paper presents a dynamic theory for calculating the deformation of 3D braided composite structures undergoing both translational and rotational motions. It also provides a simulation method for investigating the dynamic behavior of non-isotropic material plates in various applications.

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Effect of different w.ter supply on morphology, grow.h and physiological characteristics of Salix psammophila seedlings in Maow.su sandland, China

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Journal of Environmental Sciences 2001年第4期13卷 411-417页

作者： Xiao, C.-w. Lab. Quantitative Vegetation Ecol. Institute of Botany Chinese Academy of Sciences Beijing 100093 China

Response pattern w.s investigated for seedlings of Salix psammophila, a dominant shrub in Maow.su sandland, to the simulated precipitation change by artificially controlling w.ter supply at four levels. The grow.h characters, in terms of plant height, stem diameter, total branch number, total leaf number and area, total bifurcation ratio, total branch lenght and branch number, branch lenght, leaf number and leaf area of each branch order, and leaf, branch and root biomass significantly increased w.en w.ter supply increased. That w.ter supply had significant effect on biomass allocation show.d different investment pattern of biomass resource of the seedlings grow. under different w.ter supply treatments. Stomatal density of abaxial leaf surface decreased, and stomatal apparatus length and w.dth of adaxial and abaxial leaf surface increased w.th the increase of w.ter supply, w.ile Stomatal density of adaxial leaf surface w.s not affected by w.ter supply. w.ter supply obviously affected the diumal changes of photosynthetic rate, and the photosynthetic rate of the seedlings show.d strongly midday depression grow. under the 157.5 mm w.ter supply, but not grow. under higher w.ter supply. Additionally the assimilation-light response curves and flourescence efficiency more show.d that w.ter supply improve photosynthesis capacity. Finally, S. psammophila seedlings stood out by their slow.grow.h and relatively high investments in root grow.h in order to reduce tissue losing rate and consumption of w.ter resource for keeping w.ter balance under w.ter stress. The seedlings that grow. under rich w.ter supply did by their fast grow.h and relatively high investments in branch and leaf grow.h in order to improve the pow.r of capturing light energy for higher photosynthesis.

关键词： Biomass Fluorescence Morphology Photosynthesis Physiology Plants (botany) Precipitation (chemical) Seed Tissue

Getting physical w.th medical education:Exercise based virtual anatomy review.classes for medical students

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w.rld Journal of Methodology 2025年第1期15卷 20-25页

作者： Nadeesha R Samarasinghe Taniya S Nagpal Michele L Barbeau Charys M martin Division of General Surgery Faculty of MedicineUniversity of British ColumbiaVancouver V6T 1Z3BCCanada Faculty of Kinesiology Sport and RecreationUniversity of AlbertaEdmonton T6G 2R3ABCanada Anatomy and Cell Biology University of Western OntarioLondon N6A 3K7ONCanada Department of Anatomy and Cell Biology Schulich School of Medicine and DentistryThe University of Western OntarioLondon N6A 3K7ONCanada

The benefits of regular physical activity are w.ll ***,few.studies have examined the effectiveness of integrating physical activity(PA)into curricula w.thin a post-secondary *** investigate the incorporation of PA into medical curriculum,w. developed a series of optional exercise-based review.sessions designed to reinforce musculoskeletal(MSK)anatomy course *** synchronous sessions w.re co-taught by a group fitness instructor and an anatomy *** fitness instructor w.uld lead students through both strength and yoga style exercises,w.ile the anatomy instructor asked questions about relevant anatomical structures related to course material previously *** the sessions,participants w.re asked to evaluate the classes on their self-reported exam preparedness in improving MSK anatomy know.edge,PA levels,and mental *** participants completed surveys;a majority agreed that the classes increased understanding of MSK concepts(90.0%)and activity levels(97.7%).Many(70.0%)felt that the classes helped reduce *** majority of respondents(90.0%)agreed that the classes contributed to increased feelings of social ***,medical students saw.benefit in PA based interventions to supplement MSK course *** w.th increasing activity levels and promoting health behaviours,integrating PA into medical curriculum may improve comprehension of learning material,alleviate stress and foster social connectivity among medical students.

关键词： Medical education Musculoskeletal Anatomy Exercise Online learning