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A comparison of piecewise cubic Hermite interpolating polynomials,cubic splines and piecewise linear functions for the approximation of projectile aerodynamics

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defence Technology（防务技术） 2019年第5期15卷 741-757页

作者： c.A.Rabbath d.corriveau defence R&d canada Valcartier Research Centre

Modelling and simulation of projectile flight is at the core of ballistic computer software and is essential to the study of performance of rifles and projectiles in various engagement *** effective and representative numerical model of projectile flight requires a relatively good approximation of the *** aerodynamic coefficients of the projectile model should be described as a series of piecewise polynomial functions of the Mach number that ideally meet the following conditions:they are continuous,differentiable at least once,and have a relatively low *** paper provides the steps needed to generate such piecewise polynomial functions using readily available tools,and then compares Piecewise cubic Hermite Interpolating Polynomial(PcHIP),cubic splines,and piecewise linear functions,and their variant,as potential curve fitting methods to approximate the aerodynamics of a generic small arms projectile.A key contribution of the paper is the application of PcHIP to the approximation of projectile aerodynamics,and its evaluation against a set of ***,the paper provides a baseline assessment of the impact of the polynomial functions on flight trajectory predictions obtained with 6-degree-of-freedom simulations of a generic projectile.

关键词： Aerodynamic coefficients Piecewise polynomial functions cubic splines curve fitting Piecewise linear functions Piecewise cubic Hermite interpolating polynomial Projectile modelling and simulation Fire control inputs Precision Ballistic computer software

Applications of cr-Based Metal Nitride Hard coatings Using Multi-Magnetron Sputtering Sources and Elemental Metal Targets

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材料热处理学报 2004年第05B期25卷 821-826页

作者： ShicaiYang EricWiemann d.c.Teer TeercoatingsLtd. WestStoneHouse-WestStoneBerryHillIndustrialEstateDroitwichWR99ASUK InstituteforMachineToolsandFactoryManagementIWF TechnicalUniversityBerlinPascalstrasse8-9D-10587BerlinGermany

cr-based nitride hard coatings were produced by multi-magnetron sputtering sources using elemental metal materials. cr, Ti, Mo, V, Al, and Y target materials were used for the metal sources whilst nitrogen was introduced at the same time to produce multilayer nitride hard coatings. The deposition process was optimised according to the properties of hardness, adherence and wear measured using microhardness, scratch, Rockwell indentation and pin-on-disc tests. The coatings were deposited onto hard metal carbide as well as high speed steel cutting tools such as inserts and drills. The coated inserts were tested on a wide range of difficult to machine materials using a Boehringer VdF180-c cNc lathe. The machining was performed under interrupted cutting conditions and the results were compared with those obtained using an advanced commercially available TiAIN coating. The coated carbide drills were tested under dry conditions to cut hard alloy steel and the coated tool steel drills were tested under lubricant conditions to cut carbon steel with comparing the similar tests on commercial TiN coatings. These test results were compared with those from drills coated with a commercial TiN.

关键词：切割钻孔磁控管溅射渗氮 cr合金

Oxidative reforming of methane for hydrogen and synthesis gas production:Thermodynamic equilibrium analysis

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Journal of Natural Gas chemistry 2012年第5期21卷 571-580页

作者： Antonio c.d.Freitas Reginaldo Guirardello School of chemical Engineering University of Campinas (UNICAMP)Av.Albert Einstein 50013083-852Campinas-SPBrazil

A thermodynamic analysis of methane oxidative reforming was carried out by Gibbs energy minimization （at constant pressure and temperature） and entropy maximization （at constant pressure and enthalpy） methods,to determine the equilibrium compositions and equilibrium temperatures,*** cases were treated as optimization problems （non-linear programming formulation）.The GAMS 23.1 software and the cONOPT2 solver were used in the resolution of the proposed *** hydrogen and syngas production were favored at high temperatures and low pressures,and thus the oxygen to methane molar ratio （O 2 /cH 4） was the dominant factor to control the composition of the product *** O 2 /cH 4 molar ratios higher than 0.5,the oxidative reforming of methane presented autothermal behavior in the case of either utilizing O 2 or air as oxidant agent,but oxidation reaction with air possessed the advantage of avoiding peak temperatures in the system,due to change in the heat capacity of the system caused by the addition of *** calculated results were compared with previously published experimental and simulated data with a good agreement between them.

关键词： thermodynamic analysis methane oxidative reforming Gibbs energy minimization entropy maximization hydrogen and syngas production

Preliminary performance analysis and optimization based on 1d neutronics model for Indian dEMO HccB blanket

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Plasma Science and Technology 2020年第8期22卷 184-191页

作者： d AGGARWAL c dANANI M Z YOUSSEF Institute for Plasma Research GandhinagarGujarat 382428India Homi Bhabha National Institute(HBNI) AnushaktinagarMumbai 400094India University of california-Los Angeles Los AngelesCA 90095United States of America

India,under its breeding blanket R&d program for dEMO,is focusing on the development of two tritium breeding blanket concepts;namely the lead-lithium-cooled ceramic breeder and the helium-cooled ceramic breeder(HccB).The study presented in this paper focuses on the neutronic design analysis and optimization from the tritium breeding perspective of the HccB *** Indian concept has an edge-on configuration and is one of the variants of the helium-cooled solid breeder blanket concepts proposed by several partner countries in *** Indian HccB blanket having lithium titanate(Li2TiO3)as the tritium breeder and beryllium(Be)as the neutron multiplier with reduced-activation ferritic/martensitic steel structure aims at utilizing the low-energy neutrons at the rear part of the *** aim of the optimization study is to minimize the radial blanket thickness while ensuring tritium self-sufficiency and provide data for further neutronic design and thermal-hydraulic layout of the HccB *** is found that inboard and outboard blanket thicknesses of 40 cm and 60 cm,respectively,can give a tritium breeding ratio(TBR)>1.3,with 60%6Li enrichment,which is assumed to be sufficient to cover potential tritium losses and associated *** results also demonstrated that the Be packing fraction(PF)has a more profound impact on the TBR as compared to 6Li enrichment and the PF of Li2TiO3.

关键词： dEMO helium-cooled ceramic breeder blanket neutronic optimization study tritium breeding ratio

Laser particles with omnidirectional emission for cell tracking

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Light(Science & Applications) 2021年第2期10卷 197-207页

作者： Shui-Jing Tang Paul H.dannenberg Andreas c.Liapis Nicola Martino Yue Zhuo Yun-Feng Xiao seok-Hyun Yun Harvard Medical School and Wellman center for Photomedicine Massachusetts General HospitalBostonMAUSA State Key Laboratory for Mesoscopic Physics and Frontiers Science center for Nano-optoelectronics School of PhysicsPeking University100871 BeijingChina Harvard-MIT Health Sciences and Technology Massachusetts Institute of TechnologyCambridgeMAUSA

The ability to track individual cells in space over time is crucial to analyzing heterogeneous cell ***,microlaser particles have emerged as unique optical probes for massively multiplexed single-cell ***,the microlaser far-field emission is inherently direction-dependent,which causes strong intensity fluctuations when the orientation of the particle varies randomly inside ***,we demonstrate a general solution based on the incorporation of nanoscale light scatterers into *** schemes are developed by introducing either boundary defects or a scattering layer into microdisk *** resulting laser output is omnidirectional,with the minimum-to-maximum ratio of the angle-dependent intensity improving from 0.007(-24 dB)to>0.23(-6dB).After transfer into live cells in vitro,the omnidirectional laser particles within moving cells could be tracked continuously with high signal-to-noise ratios for 2 h,while conventional microlasers exhibited frequent signal loss causing tracking failure.

关键词： scattering directional intensity

2d spinel Znco_(2)O_(4) microsheet-coated functional separator for promoted redox kinetics and inhibited polysulfide dissolution

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Journal of Energy chemistry 2021年第4期30卷 468-475页

作者： Jeong seok Yeon Tae Ho Park Young Hun Ko Periyasamy Sivakumar Jun Su Kim Youngkywon Kim Ho seok Park School of chemical Engineering Sungkyunkwan UniversitySuwon 16419Gyeonggi-doRepublic of Korea Advanced Batteries Research center Korea Electronics Technology InstituteSeongnam 13509Gyeonggi-doRepublic of Korea department of Health Sciences and Technology Samsung Advanced Institute for Health Sciences and Technology(SAIHST)Sungkyunkwan UniversitySuwon 16419Gyeonggi-doRepublic of Korea department of chemistry Dongguk University-Seoul CampusJung-gu 04620 SeoulRepublic of Korea

Lithium-sulfur(Li-S)batteries are receiving increasing attention as one of the potential next-generation batteries,owing to their high energy densities and low ***,practical Li-S batteries with high energy densities are extremely hindered by the sulfur loss,low coulombic efficiency,and short cycling life originating from the polysulfide(LiPS)*** this study,two-dimensional(2d)Znco_(2)O_(4) microsheets fabricated by a facile hydrothermal process are employed to modify the separator,for improving the electrochemical performances of Li-S *** resulting 2d Zn co_(2)O_(4)-coated separator features a coating thickness of approximately 10 lm,high ionic conductivity of 1.8 m S/cm,and low mass loading of 0.2 mg/cm^(2).This 2d Znco_(2)O_(4)-coated separator effectively inhibits Li PS shuttle by a strong chemical interaction with Li PS as well as promotes the redox kinetics by Zn cO2O4-coated layers,as determined by X-ray photoelectron spectroscopy analysis,self-discharge,time-dependent permeation test,Li symmetric cell test,and Li2S nucleation ***,the Li-S batteries based on the 2d Zn co_(2)O_(4)-coated separator exhibit a high initial discharge capacity of 1292.2 m Ah/g at 0.1 ***,they exhibit excellent long cycle stability at 1 and 2 c with capacity retention of 84%and 86%even after800 cycles,corresponding to a capacity fading rate of 0.020%and 0.016%per cycle,***,these Li-S cells with a high sulfur loading at 5.3 mg/cm^(2) and low electrolyte concentration of 9 l L/mg deliver a high discharge capacity of 4.99 m Ah/cm^(2) after 200 cycles at 0.1 c.

关键词： Lithium sulfur batteries Functional separator 2d microsheet Polysulfide Redox kinetics

A comprehensive investigation on nonlinear vibration and bending characteristics of bio-inspired helicoidal laminated composite structures

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 81-100页

作者： S.SAURABH R.KIRAN d.SINGH R.VAISH V.S.cHAUHAN School of Mechanical and Materials Engineering Indian Institute of Technology Mandi

Bio-inspired helicoidal composite laminates, inspired by the intricate helical structures found in nature, present a promising frontier for enhancing the mechanical properties of structural designs. Hence, this study provides a comprehensive investigation into the nonlinear free vibration and nonlinear bending behavior of bio-inspired composite plates. The inverse hyperbolic shear deformation theory(IHSdT) of plates is employed to characterize the displacement field, with the incorporation of Green-Lagrange nonlinearity. The problem is modeled using the c0finite element method(FEM), and an in-house code is developed in the MATLAB environment to solve it numerically. Various helicoidal layup configurations including helicoidal recursive(HR), helicoidal exponential(HE), helicoidal semi-circular(HS), linear helicoidal(LH), and Fibonacci helicoidal(FH)with different layup sequences and quasi-isotropic configurations are studied. The model is validated, and parametric studies are conducted. These studies investigate the effects of layup configurations, side-to-thickness ratio, modulus ratios, boundary conditions, and loading conditions at different load amplitudes on the nonlinear vibration and nonlinear bending behaviors of bio-inspired composite plates. The results show that the laminate sequence exerts a substantial impact on both nonlinear natural frequencies and nonlinear bending behaviors. Moreover, this influence varies across different side-to-thickness ratios and boundary conditions of the bio-inspired composite plate.

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Preparation of specialists in mining surveying work in Mongolia and direction of its change in new economic situation

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中国有色金属学会会刊：英文版 2005年第S1期15卷 272-274页

作者： d. dondov c. Altantsetseg School of Mining Engineering Mongolian State University of Science and Technology MongoliaSchool of Mining Engineering Mongolian State University of Science and Technology Mongolia

due to the rapid growth of the mining sector of Mongolia, the need for preparing mining surveying specialists is increasing significantly. The history of preparing highly educated mining surveying specialists and putting their education into practice in our country is an interesting one. The main center to prepare mining surveying specialists is the School of Mining Engineering of the Mongolian State University of Science and Technology. This paper introduces the work that is being done today to prepare mining surveying specialists in Mongolia and its future purposes.

关键词： mining surveying mapping high education training research scientific work new environment future prospect

Analysis of switching conditions of chalcogenide alloys during crystallization

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Journal of University of Science and Technology Beijing 2006年第5期13卷 446-449页

作者： Wanhua Yu c.d. Wright Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China School of Engineering and computer Science University of Exeter Exeter EX4 4QF UK

To understand the principle and limitation of chalcogenide alloy Ge2Sb2Te5 （GST） in solid-state memory devices during crystallization, it was necessary to develop a physically realistic model that could reflect the electrical and thermal properties of these media. A novel comprehensive numerical model has been developed for simulating these memory devices, which describes the electrical and thermal behavior using the solution of the nonlinear, time-dependent electrical and heat conduction equation. The finite-difference-time-domain technique was adopted to compute the electrical field and heat distribution in the device. Several contributing factors that affect the crystallization switching process such as the geometry of the GST layer, temperature and electric field dependency of the electrical conductivity have been discussed. The results of the simulations were then used to provide critical guidelines for fabrication and optimization of the device performance.

关键词： chalcogenide alloy crystallization simulation modeling memory