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Scarcity within Opulence:Water Management in the Karakoram Mountains Revisited

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Journal of Mountain Science 2011年第4期8卷 525-534页

作者： Hermann KREUTZMANN Centre for Development Studies Freie Universitaet Berlin

Water management in general and in the Indus Basin in particular is concerned with the energy-efficient transportation of hydrologically exploitable resources from the upper zone to climatically favourable areas where irrigation helps to supersede arid conditions for the cultivation of crops and watering of *** other words:Human intervention sets the stage for the allocation of water from a wider catchment area in a smaller habitat where this resource is *** on mountain irrigation practices is counteracted with developments in the forelands where different frame conditions prevail and peculiar development problems *** dealing with the importance of water from the mountain regions three dimensions have to be evaluated:1) natural factors and their validity for the environmental frame conditions and technological adaptation processes;2) social factors and their impact on culture,economy and equitability;3) institutional factors and their importance for sustainable growth and for the implementation of development *** the study of decentralized irrigation systems in high mountain regions of the Indus Basin a systems theoretical approach values the complexity of interrelationships between different systems *** activities in arid mountain regions are restricted by limiting ecological factors and are characterized by certain utilization and adaptive strategies.

关键词： Irrigation Water management Institutions Development Hunza Valley Indus Basin Pakistan

FROM CRYSTALLINE BLOCK SLIPS TO DOMINANCE OF NETWORK STRETCHING——MECHANISMS OF TENSILE DEFORMATION IN SEMI-CRYSTALLINE POLYMERS

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Chinese Journal of Polymer Science 2002年第2期20卷 160-170页

作者： Y. Men Fakultaet Fuer Physik Albert-Ludwigs-Universitaet Freiburg 79104

The mechanism of tensile deformation in semi-crystalline polymers was studied based on true stress-strain curvesobtained with the aid of a video-controlled tensile set-up. The deformation is affected by both the crystalline and theamorphous phases. However, the relative weights of the two portions change with the deformation stage. At lowdeformations the coupling and coarse slips of the crystalline blocks dominate the mechanical properties, which allows thesystem to maintain a homogeneous strain distribution in the sample. As the stretching increases, at a critical strain the forcegenerated from entangled fluid portions reaches a critical value to destroy the crystallites. The dominant deformationmechanism then changes into a disaggregation - recrystallization process.

关键词： Semi-crystalline polymer Deformation mechanism Network Mechanical property

Organizational dynamics in adaptive distributed search processes: effects on performance and the role of complexity

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信息与电子工程前沿：英文版 2016年第4期17卷 283-295页

作者： Friederike WALL Department of Controlling and Strategic Management Alpen-Adria-Universitaet Klagenfurt

In this paper, the effects of altering the organizational setting of distributed adaptive search processes in the course of search are investigated. We put particular emphasis on the complexity of interactions between partial search problems assigned to search agents. Employing an agent-based simulation based on the framework of NK landscapes we analyze different temporal change modes of the organizational set-up. The organizational properties under change include, for example, the coordination mechanisms among search agents. Results suggest that inducing organizational dynamics has the potential to increase the effectiveness of distributed adaptive search processes with respect to various performance measures like the final performance achieved at the end of the search, the chance to find the optimal solution of the search problem, or the average performance per period achieved during the search process. However, results also indicate that the mode of temporal change in conjunction with the complexity of the search problem considerably affects the order of magnitude of these beneficial effects. In particular, results suggest that organizational dynamics induces a shift towards more exploration, i.e., discovery of new areas in the fitness landscape, and less exploitation, i.e., stepwise improvement.

关键词： Agent-based simulation Complexity Coordination Distributed search NK landscapes

Flow-regime transitions in fluidized beds of non-spherical particles

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Particuology 2016年第6期14卷 1-15页

作者： H. Kruggel-Emden K. Vollmari Ruhr-universitaet Bochum Universitaetsstrasse 150 D-44780 Bochum Germany

Fluidized beds frequently involve non-spherical particles, especially if biomass is present. For spheri- cal particles, numerous experimental investigations have been reported in the literature. In contrast, complex-shaped particles have received much less attention. There is a lack of understanding of how par- ticle shape influences flow-regime transitions. In this study, differently shaped Geldart group D particles are experimentally examined. Bed height, pressure drop, and their respective fluctuations are analyzed. With increasing deviation of particle shape from spheres, differences in flow-regime transitions occur with a tendency for the bed to form channels instead of undergoing smooth fluidization. The correlations available in the literature for spherical particles are limited in their applicability when used to predict regime changes for complex-shaped particles. Hence, based on existing correlations, improvements are derived.

关键词： Fluidized bed Flow regimes Non-spherical particles Pressure drop and fluctuations Bed height

A study on turbulence modulation via an analysis of turbulence anisotropy-invariants

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Science China(Physics,Mechanics & Astronomy) 2010年第3期53卷 508-513页

作者： Michael MANHART Fachgebiet Hydromechanik Technische Universitaet Muechen Munich 80333 Germany

We investigate the turbulence modulation by particles in a turbulent two-phase channel flow via an analysis of turbulence anisotropy-invariants. The fluid turbulence is calculated by a large eddy simulation with a point-force two-way coupling model and particles are tracked by the Lagrangian trajectory method. The channel turbulence follows the two-component turbulence state within the viscous sub-layer region and outside the region the turbulence tends to follow the right curve of the anisotropy-invariant. The channel turbulence, interacting with heavy particles, is modulated to the two-component turbulence limit state near the wall and is separate from the axisymmetric turbulence state in the turbulence anisotropy-invariants map. The fluctuations of streamwise component are transferred to the other two components and hence the anisotropy decreases due to particle modulation. The study has deepened the understanding of the turbulence modulation mechanism in two-phase turbulent flows.

关键词： turbulence modulation turbulence anisotropy turbulent two-phase channel flow large eddy simulation two-way coupling

Dynamical behavior of a mobile system with two degrees of freedom near the resonance

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Acta Mechanica Sinica 2011年第1期27卷 7-17页

作者： Klaus Zimmermann Igor Zeidis Faculty of Mechanical Engineering Technische Universitaet Ilmenau

The design of mobile robots that can move without wheels or legs is an important engineering and technological ***-propelling mechanisms consisting of a body that has contact with a rough surface and moveable internal masses are *** models of such systems are presented in this ***,a model of a vibration driven robot that moves along a rough horizontal plane with isotropic dry friction is *** is shown that by changing the off-resonance frequency detuning in sign,one can control the direction of motion of the *** addition,a locomotion system which moves in an environment with anisotropic viscous friction is *** all models,the method of averaging to obtain an algebraic equation for the steady-state＂average＂velocity of the system is used. Prototypes were constructed to compare the theoretical results with experimental ones.

关键词： Dynamics Friction Resonance Vibrationdriven systems

A modification of Faddeev–Popov approach free from Gribov ambiguity

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Communications in Theoretical Physics 2020年第12期72卷 137-144页

作者： Chong-yao Chen Fei Gao Yu-Xin Liu Department of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China Center for High Energy Physics Peking UniversityBeijing 100871China Institut fur Theoretische Physik Universitaet HeidelbergPhilosophenweg 1669120 HeidelbergGermany

We propose a modified version of the Faddeev–Popov(FP)quantization approach for nonAbelian gauge field theory to avoid Gribov *** show that by means of introducing a new method of inserting the correct identity into the Yang–Mills generating functional and considering the identity generated by an integral through a subgroup of the gauge group,the problem of Gribov ambiguity can be removed *** by handling the absolute value of the FP determinant with the method introduced by Williams and collaborators,we lift the Jacobian determinant together with the absolute value and obtain a local *** new Lagrangian will have a nilpotent symmetry which can be viewed as an analog of the Becchi–Rouet–Stora–Tyutin symmetry.

关键词： QCD quantization scheme Gribov copy non-Abelian field theory

Li, Be and B in phenocrysts-new tracers for magma chamber processes

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Li, Be and B in phenocrysts-new tracers for magma chamber pr...

Enrichment of topographic road database for the purpose of routing and navigation

International Conference on Continental Volcanism

作者： Sonntag,Iris Altherr,Rainer Ludwig,Thomas universitaet heidelberg Mineralogisches InstitutIm Neuenheimer Feld 23669120 HeidelbergGermany universitaet heidelberg Mineralogisches InstitutIm Neuenheimer Feld 23669120 HeidelbergGermany universitaet heidelberg Mineralogisches InstitutIm Neuenheimer Feld 23669120 HeidelbergGermany

＜正＞The island of Nisyros （Greece） is a Quaternary volcano located at the eastern end of the Hellenic arc. The magmas are typical calc-alkaline. Volcanic activity started with submarine basaltic andesites followed by subaerial lavas and pyroclastics ranging in composition from basaltic andesites to rhyolites （pre-caldera units）. Caldera formation was accompanied by rhyolitic pyroclastic deposits and lava flows. Post-caldera activity continued with extrusions of rhyodacitic domes and lava flows. Phreatic

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International Journal of Digital Earth 2014年第5期7卷 411-431页

作者： Meng Zhang Wei Yao Liqiu Meng Department of Earth and Environmental Sciences Xi’an Jiaotong UniversityXi’anChina Department of Photogrammetry and Remote Sensing Technische Universitaet MuenchenMunichGermany Department of Cartography Technische Universitaet MuenchenMunichGermany

With growing demand on multi-purpose or multi-modal navigation,the route calculation needs to traverse semantically enriched road networks for different transportation ***,operational route planning algorithms reveal rather limited performances or their potential for comprehensive applications are constrained by the unavailable or insufficient interoperation among the under-lying geo-data that are separately maintained in different spatial *** overcome this limitation,a novel approach has been proposed to integrate the routing-relevant information from different data sources,which involves three processes:(1)automatic matching to identify the corresponding road objects between different datasets;(2)interaction to refine the automatic matching result;and(3)transferring the routing-relevant information from one data-set to *** process(1),the Delimited Stroke Oriented algorithm is employed to achieve the automatic data matching between different datasets,which has revealed a high matching rate and *** uncertain matching problems occur in areas where topological conditions are too complicated or *** remaining unmatched or wrongly matched objects are treated in process(2),with the help of a series of interaction *** the basis of refined matching results after the interaction,process(3)is dedicated to automatic integration of the routing-relevant information from different data sources.

关键词： data matching data integration routing-relevant geospatial data-set road network