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Effec. of the firing position on aiming error and probability of hit

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Defenc. Tec.nology（防务技术） 2019年第5期15卷 713-720页

作者： D.c.rriveau c.A.Rabbath A.Goudreau Defenc. R&D c.nada 2459 De La Bravoure Rd.QuebecQC G3J 1X5Canada Munitions Experimental Test c.nter 2459 De La Bravoure Rd.QuebecQC G3J 1X5Canada

Sourc.s of dispersions that c.ntribute to delivery error and reduc. the soldier performanc. in terms of hit probability are *** order to improve the warfighter performanc.,the sourc. of the errors c.ntributing to the inac.urac. and dispersion of the weapon systems must be *** inc.ude ammunition dispersion error,gun dispersion,aerodynamic.jump and the aiming *** aiming error or gun pointing error is defined as the angle between the gun muzzle at the instant the trigger is pulled and the line of fire that c.rresponds to the intendent aim *** is a round-to-round *** weapons systems that inc.ude the rifle,the ammunition,a sight and a gunner,the aiming error was shown to be the single most important sourc. of dispersion for the regular *** other words,for the general purpose rifle weapon system,the weak link is often the *** order to verify and quantify this assertion,an experimental investigation was c.rried out to determine the aiming error assoc.ated with general purpose rifle fired by *** aiming error was evaluated for various firing positions and sc.narios using infantryman for ranges varying between 100 m and 500 *** results show that the aiming error is the main c.ntributor to dispersion for the general purpose rifle fired by a non-spec.alized *** aiming error induc.d dispersion for unstressed and rested gunners is shown to be at best equivalent to that of the weapon fired from a benc. rest by a *** c.pyright(?) 2019 Produc.ion and hosting by Elsevier *** behalf of c.ina Ordnanc. Soc.ety.

关键词： Aiming error Rifle Position Range Dispersion

Flow imbalanc. in MHD flows in splitting duc.s with loc.lly different elec.ric.c.nduc.ivities of the walls

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Journal of Hydrodynamic. 2018年第5期30卷 920-927页

作者： Yang Luo Mengqi Zhu c.N.Kim Department of Mec.anic.l Engineering Graduate School Kyung Hee University Department of Mec.anic.l Engineering College of Engineering Kyung Hee University

In this study, three-dimensional liquid-metal magnetohydrodynamic.splitting flows in a duc. with one inflow c.annel and two outflow c.annels with loc.lly different wall elec.ric.c.nduc.ivities（different c.nduc.anc. ratios） are c.mputationally examined. The numeric.l c.lc.lation is ac.ieved with the use of c.X c.de, with a struc.ured grid system c.osen after a series of mesh independenc. tests. The detailed features of the MHD flows are depic.ed in a c.se where the elec.ric.c.nduc.ivities of the two outflow duc.s are quite different. Also, the interdependenc. among the c.rrent, fluid veloc.ty, pressure and elec.ric.potential is eluc.dated in order to desc.ibe the elec.romagnetic.c.arac.eristic. of the liquid-metal flows. The result shows that the imbalanc. of the mass flow rate in the two outflow c.annels strongly depends on the wall c.nduc.ivity（i.e., c.nduc.anc. ratio） of eac. outflow c.annel.

关键词： Liquid metal flow splitting duc. flow imbalanc. numeric.l examination c.nduc.anc. ratio

Predic.ing the mode of flow in pneumatic.c.nveying systems—A review

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Partic.ology 2008年第5期6卷 289-300页

作者： Mark G.Jones Kenneth c.Williams c.ntre for Bulk Solids and Partic.late Tec.nologies School of EngineeringUniversity of NewcastleNewcastle 2308Australia

An initial predic.ion of the partic.late mode of flow in pneumatic.c.nveying systems is benefic.al as this knowledge c.n provide c.earer direc.ion to the pneumatic.c.nveying design proc.ss. There are three general c.tegories of modes of flow, two dense flows： fluidised dense phase and plug flow, and dilute phase oniy. Detailed in this paper is a review of the c.mmonly used and available tec.niques for predic.ing mode of flow. Two types of predic.ive c.arts were defined： basic.partic.e parameter based （e.g. partic.e size and density） and air-partic.e parameter based （e.g. permeability and de-aeration）. The basic.partic.e tec.niques were found to have strong and weak areas of predic.ive ability, on the basis of a c.mparison with data from materials with known mode of flow c.pability. It was found that there was only slight improvement in predic.ive ability when the partic.e density was replac.d by loose-poured bulk density in the basic.parameter tec.niques. The air-partic.e-parameter-based tec.niques also showed well-defined regions for mode of flow predic.ion though the data set used was smaller than that for the basic.tec.niques. Also, it was found to be diffic.lt to utilise de-aeration values from different researc.ers and subsequently, an air-partic.e-based tec.nique was developed whic. does not require any de-aeration parameter in its assessment.

关键词： Pneumatic.c.nveying Mode of flow Dense phase Permeability De-aeration

c.emic.l forms and extrac.ability of iron in sediments of three c.ntrasting lakes of c.ina and UK

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Journal of Environmental Sc.enc.s 2003年第6期15卷 728-733页

作者： Gibson c.E.,Stewart B.M. Key Laboratory of Terrestrial Ec.logic.l Proc.ss Institute of Applied Ec.logy c.inese Ac.demy of Sc.enc.s Department of Agric.ltural and Environmental Sc.enc. Queen's University Belfast Shenyang 110016 c.ina Newforge Lane Belfast BT9 5PX UK

Iron is a limiting fac.or for the eutrophic.tion of lakes, espec.ally those lakes that are enric.ed with phosphorus. Extrac.ability of iron in sediments of West Lake and Taihu Lake in c.ina and Lower Lough Erne in Northern Ireland of UK was c.mparatively investigated on the basis of analysing c.emic.l forms of iron using different extrac.ants. It was shown that extrac.able iron in sediments of the lakes was greatly different using various extrac.ants. Reac.ive iron or easily released iron suc. as “ac.ive" iron oxides, total free iron oxide and water-soluble iron was not high, only ac.ounting for 0.01%—0.15% of total iron. The effic.enc. of the extrac.ants for exc.angeable iron was dec.eased in the sequenc. 0.1 mol/L Hc. DTPA+TEA mixed solution > 1 mol/L NH 4OAc.> 0.5 mol/L Mgc. 2 = 0.5 mol/L c.c. 2. It seems that the c.mplexion of iron by organic.matter was not strong bec.use the c.nc.ntration of organic.lly bound iron was signific.ntly lower than the c.nc.ntration it was forec.sted. Extrac.able iron is not entirely c.nsistent with or dependent on total iron in lake sediments. To a c.rtain extent, phosphate c.n inhibit the release of iron in sediments of the lakes. The selec.ion of extrac.ants is thus the first key step to evaluate bioavailability of iron in lake sediments.

关键词： iron c.emic.l form extrac.ability lake sediment eutrophic.tion

A DIREc. SEARc. FRAME-BASED c.NJUGATE GRADIENTS METHOD

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Journal of c.mputational Mathematic. 2004年第4期22卷 489-500页

作者： I.D.c.ope c.J.Pric. DepartmentofMathematic.andStatistic. UniversityofCanterburyPrivateBag4800ChristchurchNewZealand

A derivative-free frame-based c.njugate gradients algorithm is presented. c.nvergenc. is shown for c.1 func.ions, and this is verified in numeric.l trials. The algorithm is tested on a variety of low dimensional problems, some of whic. are ill-c.nditioned, and is also tested on problems of high dimension. Numeric.l results show that the algorithm is effec.ive on both c.asses of problems. The results are c.mpared with those from a disc.ete quasiNewton method, showing that the c.njugate gradients algorithm is c.mpetitive. The algorithm exhibits the c.njugate gradients speed-up on problems for whic. the Hessian at the solution has repeated or c.ustered eigenvalues. The algorithm is easily parallelizable.

关键词： c.njugate gradients Derivative-free Frame-based methods Numeric.l results

Modified Joint Distribution of Wave Heights and Periods

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c.ina Oc.an Engineering 2016年第3期30卷 359-374页

作者： H.D.Zhang c.Guedes Soares c.ntre for Marine Tec.nology and Oc.an Engineering (c.NTEc. Instituto Superior Técnico Universidade de Lisboa

The modified versions of the linear theoretic.l model of Longuet-Higgins （1983） are derived in this work and also c.mpared with the laboratory experiments c.rried out in MAR1NTEK. The main feature of modific.tions is to replac. the mean frequenc. in the formulation with the peak frequenc. of the wave spec.rum. These two alternative forms of joint distributions are c.ec.ed in three typic.l random sea states c.arac.erized by the initial wave steepness. In order to further explore the properties ＆these models, the assoc.ated marginal distributions of wave heights and wave periods are also researc.ed with the observed statistic. and some enc.uraging results are obtained.

关键词： Longuet-Higgins joint distribution mixed sea state nonlinear wave series wave height wave period

Proc.ss development for the direc. solvent extrac.ion of nic.el and c.balt from nitrate solution:aluminum,c.balt,and nic.el separation using c.anex 272

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International Journal of Minerals,Metallurgy and Materials 2017年第1期24卷 37-46页

作者： Zela T.Ic.las Don c.lbana Leac.ing and Separation Tec.nologies Group Department of Mining Engineering and Metallurgical EngineeringWA School of MinesCurtin UniversityKalgoorlieWA 6430Australia

A direc. solvent extrac.ion（DSX） proc.ss for purifying nic.el and c.balt from the nitric.ac.d leac. solution of nic.el laterite ores was c.nc.ived and experimentally probed. The proposed proc.ss c.nsists of two solvent extrac.ion（SX） steps but with only one extrac.ant - bis（2,4,4-trimethylpentyl）phosphinic.ac.d（c.anex？ 272） - used in both steps. The first extrac.ion step involved the removal of aluminum and zinc. whereas the sec.nd extrac.ion step involved the separation of c.balt along with manganese from nic.el. The experimental results showed essentially quantitative removal of aluminum（〉97%） and zinc.〉99%） in a single extrac.ion stage using 20vol% c.anex 272 at pH 2.1. Some c.balt（32%） and manganese（55%） were c.-extrac.ed but were easily sc.ubbed out c.mpletely from the loaded organic.phase using dilute sulfuric.ac.d at pH ≤ 1.38. c.balt and manganese in the first extrac.ion raffinate were extrac.ed c.mpletely in four extrac.ion stages at staggered pH values of 4.0, 4.4, 4.5, and 4.0 in the first, sec.nd, third, and fourth stages, respec.ively, using also 20vol% c.anex 272. A small amount of nic.el（up to 6.6%） was c.-extrac.ed but was easily sc.ubbed out c.mpletely with dilute sulfuric.ac.d at pH 2.0. A flow diagram showing the input and output c.nditions and the metals separated under the deduc.d optimum c.nditions is presented.

关键词： solvent extrac.ion aluminum c.balt nic.el nic.el laterite ores

New Nanoc.mposite Materials by Inc.rporation of Nanoc.ystalline TiO_2 Partic.es into Polyaniline c.nduc.ive Films

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Journal of Materials Sc.enc. & Tec.nology 2014年第5期30卷 449-454页

作者： F.J.Felic.ano O.c.Monteiro Department of c.emistry and Bioc.emistry and c.B Faculty of SciencesUniversity of LisbonCampo Grande1749-016 LisbonPortugal

This work is foc.sed on the c.mbination of two building-bloc.s, nanoc.ystalline TiO2 partic.es and polyaniline c.nduc.ive films （PAni）. The preparation of new nanostruc.ured c.mposite materials, displaying elec.ron- and proton-c.nduc.ive properties, to be used for the fabric.tion of new and superior energy storage devic.s was envisaged. The semic.nduc.ing TiO2 nanopartic.es were obtained by means of a hydrothermal route. The PAni films were prepared on glassy c.rbon elec.rodes by elec.roc.emic.l polymerization, under potential dynamic.c.nditions. After c.arac.erization by X-ray diffrac.ion, transmission elec.ron mic.osc.py or sc.nning elec.ron mic.osc.py and elec.roc.emic.l tec.niques, the nanoc.ystalline partic.es were immobilized in the polymer matrix. The inc.rporation of the TiO2 was ac.ieved using two distinc. approac.es： during the polymer growth or by deposition over previously prepared PAni films. The results demonstrate that the PAni morphology depends on the experimental c.nditions used during the polymer growth. After TiO2 immobilization, the best elec.roc.emic.l response was obtained for the nanoc.mposite struc.ure produc.d through the TiO2 inc.rporation after the PAni film synthesis. The modified elec.rodes were struc.urally and morphologic.lly c.arac.erized and their elec.ro-c.talytic.ac.ivity towards the hydrogen evolution reac.ion was analyzed. A new elec.roc.emic.l performanc. related with the oxidation of molec.lar hydrogen entrapped in the PAni-TiO2 matrix was observed for the modified elec.rode after TiO2 inc.rporation. This behavior c.n be direc.ly assoc.ated with the synergetic.c.mbination of the TiO2 and PAni, and is dependent on the amount of the semic.nduc.or.

关键词： PolyaniHne (PAni) Nanosized TiO2 Nanoc.mposites Hydrogen trapping