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development of a low-frequency magnetic lightning mapping system(LFM-LMS)in North China:validation and preliminary results

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Earth and Planetary Physics 2023年第4期7卷 460-470页

作者： Xiao Li gaoPeng Lu FanChao Lyu HongBo Zhang Kainat Qamar rubin Jiang School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Key Laboratory of Atmospheric Optics Anhui Institute of Optics and Fine MechanicsHFIPSChinese Academy of SciencesHefei 230031China Collaborative Innovation Center on Forecast and Evaluation of Meteorological disasters Nanjing University of Information Science&TechnologyNanjing 210044China Key Laboratory of Transportation Meteorology of China Meteorological Administration Nanjing Joint Institute for Atmospheric SciencesNanjing 210000China Key Laboratory for Middle Atmosphere and global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

A low-frequency magnetic lightning mapping system(LFM-LMS)was built during the SHAndong Triggered Lightning Experiment(SHATLE),based on continuous measurements of magnetic field radiation from *** hardware and source-mapping techniques used by the LFM-LMS were introduced;both Monte Carlo simulations and the observation of rocket-triggered lightning examples were employed to examine the location accuracy and detection effectiveness of the *** estimated that the system’s location accuracy about 100−200 m horizontally and~200 m vertically.A natural intra-cloud lightning flash and a rocket-triggered lightning flash,both with intricate structures and discharging processes,were examined using the three-dimensional mapping *** progressing path of negative lightning leaders is usually well-defined,and its propagation speed is estimated to be(0.5−1.4)×10^(6)m/*** summary,the LFM-LMS can reconstruct the three-dimensional morphology of lightning flashes;this technology provides a efficient method for investigating the characteristics of lightning development,as well as the overall electrical strucuture of thunderstorms.

关键词： rocket-triggered lightning low-frequency magnetic field lightning mapping observation location accuracy

The Friction and Wear Properties of CrN, graphit-iC and dymon-iC Coatings in Air and under Oil-lubrication.

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材料热处理学报 2004年第05B期25卷 858-861页

作者： J. Stallard d.g Teer Teer Coatings Ltd Droitwich WorcestershireU.KTeer Coatings Ltd Droitwich WorcestershireU.K.

Hard ceramic coatings such as TiN and CrN are very successful and are widely used in improving the performance of cutting and forming tools, but they are less successful in providing protection for general machine components, such as gears and engine parts. The development of low-friction wear resistant coatings that can run dry or in a minimum amount of oil is becoming increasingly important to this industry. Two recently developed carbon-based coatings graphit-iC? and dymon-iC, which are shown to exhibit very high sliding wear resistance and low friction in dry conditions, are compared to a CrN coating under oil lubricated conditions. Long term pin-on-disc tests using a chrome steel counterface ball were carried out on coated HSS test samples. All the coatings performed well at very high applied contact pressures, exceeding 1.5 gPa, but the graphit-iC? and dymon-iC coatings also exhibited the desirable characteristic of protecting the counterface material. Reasons for this behaviour are discussed.

关键词： dLC 润滑油摩擦性能磨损性能涂层

Prediction of shear-related defect locations in semi-solid casting using numerical flow models

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中国有色金属学会会刊：英文版 2010年第S3期20卷 878-882页

作者： F.PINEAU g.d'AMOURS National Research Council of Canada Aluminum Technology Centre501 University BlvdSague nayQcG7H 8C3Canada

Contaminated surfaces of the feedstock materials in aluminum alloy casting processes often produce various types of defects which can affect the tensile properties of the final products as well as their fatigue ***-solid processing takes advantage of a much higher apparent viscosity of the die cast materials by limiting the risk of oxides formed at the free surfaces to become incorporated into the casting when the material is injected into the *** of existing semi-solid processes that use billets as feedstock material are however tied up with a different type of contaminated *** the injection phase,the external-skin on the periphery of the billet,which has been in contact with air and lubricant during the transfer in the shot sleeve,can be incorporated into the *** subjected to a heat treatment,the lubricant is decomposed and produces lens shape *** might be a cause of reject for most structural *** avoid this kind of defects,the paths along which the billet skin evolves must be controlled during *** order to investigate the possibility of skin inclusion into cast parts during injection of the billet,a two-phase finite element mixture model is employed to model the metal *** formation of a skin on the periphery of the billet is modeled by setting an initial solid phase concentration profile in the radial *** observations of the real castings show that the approach is able to model the shear layers and to predict the paths along which the"lens porosity"defects could be *** Arbitrary Eulerian-Lagangian(ALE) method is also investigated and appears to be very promising to follow the skin movement in the casting.

关键词： oxide skin defects two-phase flow finite element modeling Arbitrary Eulerian-Lagangian(ALE) method

An investigation of roof runoff during rain events at the Royal Military College of Canada and potential discharge to Lake Ontario

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Journal of Environmental Sciences 2011年第7期23卷 1072-1078页

作者： david g. Kelly Ron d. Weir Steven d. White Analytical Sciences group & SLOWPOKE-2 Facility at RMC Department of Chemistry and Chemical Engineering Royal Military College of Canada 11 General Crerar Crescent

The Royal Military College of Canada, located on the north eastern shore of Lake Ontario, possesses an abundance of copper roofs and lacks surface water treatment prior to discharge into Lake Ontario. Rainwater, roof runoff and soil samples were collected and analyzed for copper and other parameters. Copper was consistently detected in runoff samples with average concentrations of 3200 ± 2100 μg/L. Multivariable linear regression analysis for a dependant copper runoff concentration yielded an adjusted R 2 value of 0.611, based on an independent variable model using minimum temperature, maximum temperature, total precipitation, and wind speed. Lake water samples taken in the vicinity of storm water outfalls draining areas with copper roofs ranged from 2.0 to 40 μg/L copper. Such data exceed the 2.0 μg/L Canadian Water Quality guidelines for the Protection of Aquatic Life as outlined by the Canadian Council of Ministers of the Environment （CCME）. Analysis of raw, filtered and digested forms suggested that the majority of copper present in runoff and lake water samples was in a dissolved form. The majority of soils taken in this study displayed copper concentrations below the 63 μg/g CCME residential/parkland land use limits. These findings suggested that ion exchange processes between runoff water and soil do not occur to a sufficient extent to elevate copper levels in soil. It may therefore be concluded that the eventual fate of copper, which is not discharged via storm water outfalls, is lost to the water table and Lake Ontario through the sub-soil.

关键词： copper roof runoff Lake Ontario Canadian water quality guidelines for the protection of aquatic life

NUMERICAL SOLUTIONS OF INCOMPRESSIBLE EULER ANd NAVIER-STOKES EQUATIONS BY EFFICIENT dISCRETE SINgULAR CONVOLUTION METHOd

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Acta Mechanica Sinica 2000年第3期16卷 223-239页

作者： d.C.Wan g.W.Wei Shanghai Univ Shanghai Inst Appl Math&MechShanghai 200072Peoples R China Natl Univ Singapore Dept Computat SciSingapore 119260Singapore

An efficient discrete singular convolution (dSC) method is introduced to the numerical solutions of incompressible Euler and Navier-Stokes equations with periodic boundary conditions. Two numerical tests of two-dimensional Navier-Stokes equations with periodic boundary conditions and Euler equations for doubly periodic shear layer flows are carried out by using the dSC method for spatial derivatives and fourth-order Runge-Kutta method for time advancement, respectively. The computational results show that the dSC method is efficient and robust for solving tho problems of incompressible flows, and has the potential of being extended to numerically solve much broader problems in fluid dynamics.

关键词： incompressible flows periodic boundary dSC method fourth-order Runge-Kutta method

Solid state interfacial reactions in electrodeposited Cu/Sn couples

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中国有色金属学会会刊：英文版 2010年第1期20卷 90-96页

作者：汤文明 d. g. IVEY School of Materials Science and Engineering Hefei University of Technology department of Chemical and Materials Engineering University of Alberta Edmonton Alberta T6G 2G6 Canada

Cu/Sn couples, prepared by sequentially electroplating Cu and Sn layers on metallized Si wafers, were employed to study the microstructures, phases and the growth kinetics of Cu-Sn intermediate phases, when electroplated Cu/Sn couples were aged at room temperature or annealed at temperatures from 373 K to 498 K for various time. Only Cu6Sn5 formed in aged couples or couples annealed at temperature below 398 K. The Cu6Sn5 layer was continuous, but not uniform, with protrusions extending into the Sn matrix. When Cu/Sn couples were annealed at temperatures from 423 K to 498 K, two continuous and uniform Cn6Sn5/Cu3Sn layers formed within the reaction region between Sn and Cu. There were many voids near the Cu3Sn/Cu interface and within the Cu3Sn layer. Cu6Sn5 and Cu3Sn formations both follow parabolic growth kinetics with activation energies of 41.4 kJ/mol for Cu6Sn5 and 90.4 kJ/mol for Cu3Sn, respectively.

关键词：电镀铜固态反应锡退火温度生长动力学种族金属硅微结构

Synthesis of layered LiMnO_2 by in situ oxidation-intercalation and a study of the reaction mechanism and electrochemical performance

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Chinese Science Bulletin 2005年第3期50卷 213-216页

作者： d.g.Evans Key Laboratory of Science and Technology of Controllable Chemical Reactions Ministry of EducationBeijing University of Chemical Tech- nologyBeijing 100029China

Using Mn(OH)2 as precursor, LiOH as lithiat- ing agent and (NH4)2S2O8 as oxidant, layered o-LiMnO2 was obtained by a novel method——in situ oxidation-intercalation under mild conditions (80℃). The product was characterized by XRd, ICP, TEM and Li-NMR. The results reveal that 7 orthorhombic LiMnO2 with high purity and good crystallin- ity can be obtained by this method. during electrochemical tests, a LiMnO2/Li cell shows an initial reversible capacity of 208 mAh·g?1 and a reversible capacity of 180 mAh·g?1 after 30 cycles at room temperature.

关键词： LiMnO2 氧化反应电化学特性锂离子电池分析方法

Applications and verification of a computational energy dynamics model for mine climate simulations

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International Journal of Mining Science and Technology 2020年第4期30卷 483-493页

作者： g.danko d.Bahrami C.Stewart department of Mining and Metallurgical Engineering University of NevadaRenoNV 89557USA School of Mechanical Engineering University of QueenslandQueensland 4072Australia

A complete thermodynamic model is described for temperature and heat flow distribution simulation for ventilation networks in underground *** method is called the Computational Energy dynamics(CEd)model of the heat,mass,and energy *** Thermal and Humidity(TH)transport elements of the full model are described for advection,convection,and accumulation,encompassing heat capacity,radiation,latent heat for evaporation,and condensation in the airways,as well as variable heat conduction and accumulation in the rock *** thermal flywheel effect for time-dependent temperature field applications is included in the model solution.A CEd model validation exercise is described,directly evaluating the iterated,minimized energy balance errors for the mechanical and thermal energy components for each network branch after a converged solution is determined.A simulation example relevant to mine safety and health is shown with the CEd-TH model,demonstrating its capabilities in efficiency and accuracy in comparison with measurement results.

关键词： Mine climate simulation dynamic heat flow model Coupled heat and moisture transport Computational energy dynamics Mine safety and health

Expanding the view of a standard colonoscope with the Third Eye~ Panoramic^(TM) cap

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World Journal of gastroenterology 2015年第37期21卷 10683-10687页

作者： Moshe rubin Leigh Lurie Konika Bose Sang H Kim New York Presbyterian-Queens Weill Cornell Medical College

AIM: To evaluate a new imaging device for colonoscopy that adds two side viewing CMOS lenses, the Third EyePanoramic. ***: In this prospective observational feasibility study, 33 patients, 18 male and 15 female, underwent routine screening, surveillance or diagnostic colonoscopy with the new Third EyePanoramic. cap clipped on to the distal tip of a high definition Fuji EC530-LS Slim Colonoscope. All procedures were performed at the New York Presbyterian-Queens Endoscopy unit by two experienced endoscopists(rubin M and Kim SH). Main outcome measurements included evaluation of the image quality of the Third EyePanoramic. cap, adenoma detection rate, cecal intubation rate, withdrawal time and total procedure ***: The Third EyePanoramic. cap enabled enhanced views without affecting the quality of the colonoscope's image or its handling characteristics through the colon. Ileal intubation was accomplished in most cases, but was more challenging. The side view lenses detected polyps and diverticula hidden behind folds and in flexures not seen on the standard *** side view lenses were easily cleaned utilizing an EndogatorIrrigation Pump(Medivators, Minneapolis,MN, United States) by angling the scope tip against the mucosa while washing. The cecum was reached in all33 patients. Mean cecal intubation time was 8.19 ± 2.17 min, mean withdrawal time was 10.15 ± 5.56 min and mean total procedure time was 20.31 ± 5.14 min. The overall adenoma detection rate was 44%.CONCLUSION: The Third EyePanoramic. cap enables wide view colonoscopy with enhanced visualization utilizing standard forward view colonoscopes.

关键词： Colonoscopy Adenoma detection rate Endoscopic tech