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Impact of systems modelling on agronomic research and adoption of new practices in smallholder agriculture

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Journal of Integrative Agriculture 2015年第8期14卷 1478-1489页

作者： D J Connor h van Rees p S Carberry The University of Melbourne Crop Facts Mandurang South 3551 Australia Commonwealth Scientific and Industrial Research Organization

An analysis of the impact of simulation modelling in three diverse crop-livestock improvement projects in Agricultural Research for Development（AR4D） reveals benefits across a range of aspects including identification of objectives, design and implementation of experimental programs, effectiveness of participatory research with smallholder farmers, implementation of system change and scaling-out of *** planning change, farmers must consider complex interactions within both biophysical and socioeconomic aspects of their crop and animal production *** this, whole-farm models that include household models of food, workload and financial requirements have the most utility and *** analysis also proposes improvements in design and implementation of AR4 D projects to improve the utility of simulation modelling for securing positive agronomic and livestock outcomes and lasting legacies.

关键词： agricultural systems animal production crop production modelling research for development

Density determination and simulation of Inconel 718 alloy at normal and metastable liquid states

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Journal of Materials Science & Technology 2018年第3期34卷 436-439页

作者： h.p.Wang C.h.Zheng p.F.Zou S.J.Yang L.hu B.Wei Department of Applied physics Northwestern Polytechnical University

The density of liquid Incone1718 alloy was experimentally measured by electrostatic levitation technique, where the maximum undercooling of 100 K was realized for the commercial sample. The measured density of liquid lnconel 718 alloy is 7.39 g cm^-3 at the liquidus temperature of 1663 K which was confirmed by DSC experiment, with the linear temperature coefficient of -6.89 × 10^-4 gcm^-3 K^-1. Correspondingly, four ternary Ni-Cr-Fe compositions were designed to simulate the density of liquid lnconel 718 alloy with 16000 atoms, from which the liquid structure is revealed by pair distribution function, The predicted result shows a remarkable enhancement with the decrease of temperature at the first neighbor distance.

关键词： Undercooling Density Liquid metal and alloy Levitation

Influence of surface liquid segregation on corrosion behavior of semi-solid metal high pressure die cast aluminium alloys

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中国有色金属学会会刊：英文版 2010年第S3期20卷 837-841页

作者： E.p.MASUKU h.MLLER U.A.CURLE p.C.pISTORIUS Materials Science and Manufacturing Council for Scientific Industrial ResearchPretoriaSouth Africa Department of Materials Science and Engineering Carnegie Mellon UniversityPittsburghUSA

The corrosion behavior(in chloride medium) of the surface layer of SSM-hpDC plates of alloys 7075-T6 and 2024-T6 was compared with that of the wrought alloys 7075-T6 and *** testing was performed in deaerated 3.5%NaCl *** separate tests,the open-circuit potential was monitored in aerated 3.5% NaCl for 30 min after *** electrochemical tests show that there is no significant difference in the pitting potential of the wrought alloys and that of the Cu-enriched surfaces of the SSM-hpDC alloys.

关键词： semi-solid metal(SSM) forming wrought aluminium alloys alloy 7075 alloy 2024 corrosion surface liquid segregation

Electron trajectory evaluation in laser-plasma interaction for effective output beam

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Chinese physics B 2010年第6期19卷 344-348页

作者： p. Zobdeh R. Sadighi-Bonabi h. Afarideh Department of physics Qom Branch Islamic Azad University Qom Iran Department of physics Sharif University of Technology 11365-9567 Tehran Iran Department of physics Amirkabir University of Technology Tehran Iran

Using the ellipsoidal cavity model, the quasi-monoenergetic electron output beam in laser-plasma interaction is described. By the cavity regime the quality of electron beam is improved in comparison with those generated from other methods such as periodic plasma wave field, spheroidal cavity regime and plasma channel guided acceleration. Trajectory of electron motion is described as hyperbolic, parabolic or elliptic paths. We find that the self-generated electron bunch has a smaller energy width and more effective gain in energy spectrum. Initial condition for the ellipsoidal cavity is determined by laser-plasma parameters. The electron trajectory is influenced by its position, energy and cavity electrostatic potential.

关键词： electron intense laser plasma accelerator laser wake field bubble regime wave breaking

Review of deployment technology for tethered satellite systems

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Acta Mechanica Sinica 2018年第4期34卷 754-768页

作者： B.S.Yu h.Wen D.p.Jin State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics

Tethered satellite systems（TSSs） have attracted significant attention due to their potential and valuable applications for scientific research. With the development of various launched on-orbit missions, the deployment of tethers is considered a crucial technology for operation of a TSS. Both past orbiting experiments and numerical results have shown that oscillations of the deployed tether due to the Coriolis force and environmental perturbations are inevitable and that the impact between the space tether and end-body at the end of the deployment process leads to complicated nonlinear phenomena. hence, a set of suitable control methods plays a fundamental role in tether deployment. This review article summarizes previous work on aspects of the dynamics, control, and ground-based experiments of tether deployment. The relevant basic principles, analytical expressions, simulation cases, and experimental results are presented as well.

关键词： Tethered satellite Deployment Dynamics Control Experiment

Low-complexity online correction and calibration of pedestrian dead reckoning using map matching and GpS

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Geo-Spatial Information Science 2019年第2期22卷 114-127,I0004页

作者： Fabian hölzke Johann-p.Wolff Frank Golatowski Christian haubelt Institute of Applied Microelectronics and CE University of RostockRostockGermany

Dead Reckoning is a relative positioning scheme that is used to infer the change of position relative to a point of origin by measuring the traveled distance and orientation *** Dead Reckoning(pDR)applies this concept to walking *** method can be used to track someone's movement in a building after a known landmark like the building's entrance is ***,the movement of a foot and the corresponding direction change is measured and summed up,to infer the current *** and integrating the corresponding physical parameters,*** inertial sensors,introduces small errors that accumulate quickly into large distance *** of a buildings geography may reduce these errors as it can be used to keep the estimated position from moving through walls and onto likely *** this paper,we use building maps to improve localization based on a single foot-mounted inertial *** describe our localization method using zero velocity updates to accurately compute the length of individual steps and a Madgwick filter to determine the step *** though the computation of individual steps is quite accurate,small errors still accumulate in the long *** show how correction algorithms using likely and unlikely paths can rectify errors intrinsic to pedestrian dead reckoning tasks,such as orientation and displacement drift,and discuss restrictions and disadvantages of these *** also present a method of deriving the initial position and orientation from GpS *** verify our pDR correction methods analyzing the corrected and raw trajectories of six participants walking four routes of varying length and complexity through an office building,walking each route three *** quantitative results show an endpoint accuracy improvement of up to 60%when using likely paths and 23%when using unlikely ***,both approaches can also decrease accuracy in certain *** identify those scenarios and

关键词： Indoor localization pedestrian Dead Reckoning(pDR) Inertial Navigation System(INS) map matching Zero Velocity Update(ZUpT)

A four parameter cubic equation of state with temperature dependent covolume parameter

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Chinese Journal of Chemical Engineering 2019年第5期27卷 1132-1148页

作者： pradnya N.p.Ghoderao Vishwanath h. Dalvi Mohan Narayan Department of physics Institute of Chemical TechnologyMumbai 400019India Department of Chemical Engineering Institute of Chemical TechnologyMumbai 400019India

A four-parameter, Ghoderao–Dalvi–Narayan 2 cubic equation of state(GDN2 CEOS), is presented which incorporates the following: 1. The experimental value of the critical compressibility factor has been used as a fixed input parameter for calculations;2. All the parameters(a, b, c, d) of CEOS are temperature dependent functions in the subcritical region and are temperature independent functions in the supercritical region and;3. A new α function is introduced with two compound specific parameters which are estimated by matching saturated vapor pressure at two fixed temperature points Tr= 0.5, 0.7. Our formalism enables us to cast three of the four parameters of the CEOS as a function of the remaining parameter. The proposed CEOS is used to predict properties of 334 pure compounds, including saturated vapor pressure and liquid density, compressed liquid density, heat capacities at the constant pressure and volume, enthalpy of vaporization, sound velocity. To calculate thermodynamic properties of a pure compound, the present CEOS require the critical temperature, the critical pressure, the pitzer’s acentric factor, the critical compressibility factor, and two parameters of the alpha function. The saturated liquid density predictions for pure fluids are very accurate when compared with GDN1(Ghoderao–Dalvi–Narayan 1),MpR(Modified peng–Robinson), and pT(patel–Teja) equations of state. Unlike MpR EOS, the proposed temperature dependent covolume parameter b in the present work satisfies all the constraints mentioned in the literature to avoid thermodynamic inconsistencies at the extreme temperature and pressure. Using van der Waals one-fluid mixing rule, the present CEOS is further used to predict bubble pressure and the vapor mole fraction of binary mixtures.

关键词： phase equilibria Thermodynamic properties Vapor-liquid equilibria The cubic equation of state Covolume parameter Supercritical region

Microstructures and Mechanical properties of Al/Mg Alloy Multilayered Composites produced by Accumulative Roll Bonding

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Journal of Materials Science & Technology 2011年第1期27卷 15-21页

作者： h.S. Liu B. Zhang G.p. Zhang Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Key Laboratory for Anisotropy and Texture of Materials of Ministry of Education School of Materials & Metallurgy Northeastern University Shenyang 110004 China

Al/Mg alloy multilayered composites were produced successfully at the lower temperature（280 C） by accumulative roll bonding（ARB） processing *** microstructures of Al and Mg alloy layers were characterized by scanning electron microscopy and transmission electron *** hardness and three-point bending tests were conducted to investigate mechanical properties of the *** is found that Vickers hardness,bending strength and stiffness modulus of the Al/Mg alloy multilayered composite increase with increasing the ARB *** and crack propagation along the interface are the two main failure modes of the multilayered composite subjected to bending *** and fracture mechanisms of the composite are analyzed.

关键词： Accumulative roll bonding(ARB) Al/Mg alloy multilayered composite Ultra-fine grains hardness Bending properties

Influence of Turbulators in Blade Cooling passages on Film hole Discharge Coefficients

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Journal of Thermal Science 2004年第3期13卷 245-254页

作者： h.-p. SChIFFER J. TAEGE F. hASELBACh Rolls-Royce Deutschland Eschenweg 11 D-15827 Dahlewitz GermanyRolls-Royce Deutschland Eschenweg 11 D-15827 Dahlewitz GermanyRolls-Royce Deutschland Eschenweg 11 D-15827 Dahlewitz Germany

This paper details the results of a joint project between Rolls-Royce Deutschland (RRD) and the Northwestern polytechnical University of China (NWpU). The objective of the project was the determination of the influence of tabulators in turbine blade cooling passages on film hole discharge coefficients (Cd coefficients). A large-scale plexiglas model was used by the NWpU to measure the turbulator influence on Cd coefficients for a wide range of different geometrical parameters, Reynolds numbers and cooling flow off take ratios. RRD specified the comprehensive test matrix and analysed the test data. The CFD code FLUENT was used by RRD for numerical simulation of the test cases with the main objective to support the interpretation of observed trends. Both, experimental and numerical results will be presented in this paper for a selection of test configurations.

关键词： film hole discharge coefficient turbulator blade cooling.