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Nitriding of Aluminium Alloy in Nitrogen and Nitrogen-Helium mixture Using 100 Hz-Pulsed DC Glow Discharge

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Plasma Science and Technology 2010年第4期12卷 452-460页

作者： Nasrullah KHAN m.SHOAIB SHAH R.AHmAD Department of Physics GC University

Nitriding of aluminium alloy （***0.8） in nitrogen and nitrogen-helium mixture was carried out by using 100 Hz-pulsed DC glow discharge. Samples are treated for different durations, namely 4 h, 8 h and 12 h, in nitrogen plasma as well as in a mixture of nitrogen- helium plasma for the same processing duration of 4 h. All nitriding treatments are carried out at an input power of 100 W, filling pressure of 1 mbar and substrates temperature of 250~C. X-ray diffraction （XRD） results show an expansion in lattice spacing and consequently shift of diffraction peaks towards lower angle with the addition of helium in nitrogen plasma. Surface morphology of the treated sample is investigated by scanning electron microscopy （SEm） and energy dispersive X-ray analysis （EDX）. Vickers micro-hardness testing results show increases in surface hardness with processing duration as well as with the addition of helium in nitrogen plasmas. This increase of surface hardness may be attributed to the diffusion of nitrogen content in the surface layer generating internal stresses. It is observed that the addition of helium positively affects the nitriding of samples.

关键词： nitrogen-helium mixture plasma nitriding X-ray diffraction surface hardness

Calculation of multi-layer plate damper under one-axial load

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Chinese Physics B 2016年第2期25卷 256-261页

作者：闫辉张露姜洪源 Alexander m.Ulanov School of mechatronics Engineering Harbin Institute of Technology Harbin 150001 China Samara State Aerospace University Moskovskoe Shosse Samara 443086 Russia

A multi-layer damper with waved plates under one-axial load is considered. A method of theoretical calculation of its energy dissipation coefficient is proposed. An experimental research of own frequencies and vibration transfer ratios for different parameters of damper structure, harmonic vibration load and random load is performed. Results of this research are approximated by functions; it is possible to use these functions for the calculation of the damper too.

关键词： plate damper energy dissipation coefficient elastic-damping characteristics amplitude-frequencycharacteristics

An efficient method for unfolding kinetic pressure driven VISAR data

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High Power Laser Science and Engineering 2015年第3期3卷 50-58页

作者： m.Hess K.Peterson A.Harvey-Thompson Sandia National Laboratories

Velocity Interferometer System for Any Reflector(VISAR) [Barker and Hollenbach, J. Appl. Phys. 43, 4669(1972)]is a well-known diagnostic that is employed on many shock physics and pulsed-power experiments. With the VISAR diagnostic, the velocity on the surface of any metal flyer can be found. For most experiments employing VISAR, either a kinetic pressure [Grady, mech. mater. 29, 181(1998)] or a magnetic pressure [Lemke et al., Intl J. Impact Eng. 38,480(2011)] drives the motion of the flyer. moreover, reliable prediction of the time-dependent pressure is often a critical component to understanding the physics of these experiments. Although VISAR can provide a precise measurement of a flyer's surface velocity, the real challenge of this diagnostic implementation is using this velocity to unfold the timedependent pressure. The purpose of this paper is to elucidate a new method for quickly and reliably unfolding VISAR data.

关键词： laser driven blast wave pulsed-power VISAR

Effect of Streamwise Fences on Secondary Flows and Losses in a Twodimensional Turbine Rotor Cascade

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Journal of Thermal Science 2006年第4期15卷 296-305页

作者： m.Govardhan A.Rajender J.P.Umang Thermal Turbomachines Laboratory Department of Mechanical EngineeringIndian Institute of Technology MadrasChennai 600036India

To control secondary flows, streamwise fences were attached to end wall of a linear turbine rotor cascade. The cascade had 8 blades of 400 mm long and 175 mm chord. The blades deflected the flow by 120°. The fences were made out of 0.7 mm thick brass sheet and the heights of the fences were 14 mm, 18 mm respectively. The curvature of the fences was the same as that of the blade camber line. The fences were fixed normal to the end wall and at half pitch away from the blades. The experimental program consists of total pressure, static pressure measurements at the inlet and outlet of the cascade, by using five-hole probe. In addition, static pressure on the blade suction surface and pressure surface was also obtained. Fences are effective in preventing the movement of the pressure side leg of the horseshoe vortex. Consequently the accumulation of low energy fluid on the suction surface is minimised. End wall losses are reduced by the fences due to weakening of the end wall cross flow.

关键词： Turbine cascade streamwise fences loss core lift coefficient

Nanosized complex fluorides based on Eu^(3+) doped Sr_2LnF_7(Ln=La, Gd)

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Journal of Rare Earths 2014年第3期32卷 242-247页

作者： m.Runowski S.Balabhadra S.Lis Department of Rare Earths Faculty of Chemistry Adam Mickiewicz University

A simple co-precipitation approach taking place between Ln3＋, Sr2＋ cations and F anions, led to the formation of nanocrystalline Eu3＋ doped Sr2LnF7 （Ln-La and Gd） complex fluorides. The reaction was carried out in the presence of polyeth- ylene glycol, PEG 6000 as a surfactant/surface modifier, providing small size and homogeneity of the products. The synthesized compounds were composed of small nanoparticles with an average size of 15 nm. All obtained Eu3＋ doped compounds exhibited an intensive red luminescence. In the case of gadolinium based compounds, the energy transfer phenomena could be observed from Gd3＋ ions to Eu3＋ ions. In order to study the structure and morphology of the synthesized fluorides, powder X-ray diffraction （XRD） and transmission electron microscopy （TEm） measurements were performed. Also FT-IR spectra of the products were re- corded, revealing the presence of PEG molecules on the nanoparticles suN＇ace. A spectrofluorometry technique was applied to examine optical properties of the synthesized nanoparticles. Excitation and emission spectra as well as luminescence decay curves were measured and analysed. The performed analysis revealed a red luminescence, typical for the Eu3＋ ion situated in the inorganic, highly symmetric matrix. Concentration quenching phenomena and lifetimes shortening, together with an increasing of the Eu3＋ doping level, were observed and discussed. Judd-Ofelt analysis was also performed for all doped samples, in order to support the registered spectroscopic data and examine in details structural and optoelectronic properties of the synthesized nanomaterials.

关键词： luminescence Eu3+ doping complex strontium lanthanide fluorides nanoparticles Sr2LnF7 Sr0.69La0.31F2.31 rare earths

Fluorescence-guided hepatobiliary surgery with long and short wavelength fluorophores

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Hepatobiliary Surgery and Nutrition 2020年第5期9卷 615-639页

作者： Thinzar m.Lwin Robert m.Hoffman michael Bouvet Department of Surgery University of California San DiegoSan DiegoCAUSA AntiCancer Inc.San DiegoCAUSA VA San Diego Healthcare System San DiegoCAUSA

Importance:Fluorescence-guided surgery(FGS)is a potentially powerful tool for hepatobiliary(HPB)*** high sensitivity of fluorescence navigation is especially useful in settings where tactile feedback is ***:The present narrative review evaluates literature on the use of FDA-approved fluorophores such as methylene blue(mB),5-aminolevulinic acid(5-ALA),and indocyanine green(ICG)for clinical intra-operative image-guidance during HPB *** Review:Approaches such as dosing,timing,imaging devices and comparative endpoints are *** feasibility and safety of fluorophores in visualizing the biliary tree,identify biliary leaks,outline anatomic hepatic segments,identify tumors,and evaluate perfusion and graft function in liver transplants are ***:Tumor-specific probes are a promising advancement in FGS with a greater degree of *** current status of tumor-specific probes being evaluated in clinical trials are *** and Relevance for Reviews:Relevant discussion of promising tumor-specific probes in pre-clinical development are ***-guidance in HPB surgery is relatively new,but current literature shows that the dyes are reliably able to outline desired structures with a variety of dosing,timing,and imaging devices to provide real-time intra-operative anatomic information to *** of tumor-specific probes will further advance the field of HPB surgery especially during oncologic resections.

关键词： Fluorescence-guided surgery(FGS) methylene blue(mB) 5-aminolevulinic acid(5-ALA) indocyanine green(ICG) hepatobiliary surgery(HPB surgery) tumor-specific probes near-infrared fluorescence(NIR fluorescence)

Revisiting factors contributing to the strength of cemented backfill support system:A review

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Journal of Rock mechanics and Geotechnical Engineering 2023年第6期15卷 1615-1624页

作者： N.m.Chiloane F.K.mulenga Department of mining Engineering University of South AfricaFlorida CampusPrivate Bag X6Johannesburg1710South Africa

This paper provides a review of the intrinsic and extrinsic factors affecting the uniaxial compressive strength(UCS)of cemented tailings backfill(CTB).The consideration is that once CTB is poured into underground stopes,its strength is heavily influenced by factors internal to the CTB as well as the surrounding mining ***-reviewed journal articles,books,and conference papers published between 2000 and 2022 were searched electronically from various databases and *** sources,such as doctoral theses,were obtained from academic *** important finding from the review is that the addition of fibers was reported to improve the UCS of CTB in some studies while decrease in *** discrepancy was accounted to the different properties of fibers *** research is therefore needed to determine the“preferred”fiber to be used in *** findings were also reported on the effects of stope size on the UCS of ***,the use of fly ash as an alternative binder may be threatened in the future when reliance on the coal power ***,an alternative cementitious by-product to be used together with furnace slag may be required in the ***,while most studies on backfill focused on single-layered structures,layered backfill design models should also be investigated.

关键词： Cemented tailings backfill(CTB) Uniaxial compressive strength(UCS) Extrinsic factors Intrinsic factors Underground support

Non-monotonic temperature evolution of nonlocal structure–dynamics correlation in CuZr glass-forming liquids

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Chinese Physics B 2021年第7期30卷 370-375页

作者： W J Jiang m Z Li Department of Physics and Beijing Key Laboratory of Opto-electronic Functional materials&micro-nano Devices Renmin University of ChinaBeijing 100872China

The structure–dynamics correlations in a nonlocal manner were investigated in CuZr metallic glass-forming liquids via classical molecular dynamics simulations.A spatial coarse-graining approach was employed to incorporate the nonlocal structural information of given structural order parameters in the structure–dynamics *** is found that the correlation between structure order parameters and dynamics increases with increasing coarse-graining length and has a characteristic length ***,the characteristic correlation length exhibits a non-monotonic temperature evolution as temperature approaches glass transition temperature,which is not sensitive to the considered structure order *** results unveil a striking change in the structure–dynamics correlation,which involves no fitting theoretical *** findings provide new insight into the structure–dynamics correlation in glass transition.

关键词： metallic glass-forming liquid structure–dynamics correlation molecular dynamics simulation

Analysis of surface roughness of rock dust reinforced AA6061-mg matrix composite in turning

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Journal of magnesium and Alloys 2021年第5期9卷 1686-1693页

作者： R.Balachandhar R.Balasundaram m.Ravichandran Department of mechanical Engineering Pavender Barathidasan College of Engineering and TechnologyTiruchirappalli620024Tamil NaduIndia Department of mechanical Engineering K.Ramakrishnan College of EngineeringTiruchirappalli621112Tamil NaduIndia Department of mechanical Engineering SRM Institute of Science and TechnologyTiruchirappalli Campus621105Tamil NaduIndia

This work,examines the Surface Roughness(SR)of composite consisting Aluminium alloy(AA6061),magnesium and Rock dust during turning *** study the performance,three different test specimens with different constituents of Al 6061-T6,AZ31 and Rock dust were prepared by stir casting *** experiments were carried out using mTAB Siemens-CNC *** input parameters for machining are speed,depth of cut&feed and output response is surface roughness For each test specimen,there are 15 turning operations were performed using Box-Ben hen Design *** analyze the process parameters for SR,the models of ANOVA and Decision Tree(DT)algorithms were *** algorithms are confirmed that,speed is the most significant factor for *** addition of AZ 31 with 1%and rock dust of 2%in AA6061 produced better surface *** models of linear regression,multilayer perception and support vector regression from data science were formulated to find the relationship between *** these models multi layer perception produced minimum root mean square error.

关键词： Composite Turning Surface roughness Anova Decision tree Regression