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Effect of silicon carbide and wire-mesh reinforcements in dissimilar grade aluminium explosive clad composites

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Defence Technology（防务技术） 2020年第6期16卷 1160-1166页

作者： s.saravanan k.Raghukandan Department of Mechanical Engineering Annamalai UniversityAnnamalainagarTamilnaduIndia Department of Manufacturing Engineering Annamalai UniversityAnnamalainagarTamilnaduIndia

Aluminium composites are inevitable in the manufacture of aircraft structural elements owing to less weight,superior corrosion resistance and higher specific *** composites reduce the weight of the aircraft,improve the fuel efficiency and enhance the maintenance *** study proposes the development of dissimilar grade aluminium(aluminium 1100-aluminium 5052)composites with different reinforcement’s viz.,stainless steel wire-mesh,silicon carbide(siC)powders and siC powder interspersed wire-mesh,by explosive cladding ***-mesh enhances the friction and restricts the movement of flyer plate to craft a defect free clad,while siC particles form a band on the *** strength is obtained when siC powder interspersed wire mesh is employed as *** dissimilar aluminium explosive clad with siC particle reinforcement results in lower strength,which is higher than that of the weaker parent alloy and that of the conventional dissimilar aluminium explosive clads without any reinforcement.

关键词： Explosive cladding Aluminium Wire mesh silicon carbide Microstructure strength

Plasmonic enhancement of upconversion emission in Ag@NaYF4:Er^3+/Yb^3+phosphor

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Journal of Rare Earths 2018年第9期36卷 903-910页

作者： s.k.Maurya s.R Tiwari A.kumar k.kumar Optical Materials and Bio-imaging Research Laboratory Department of Applied PhysicsIndian Institute of Technology(Indian School of Mines)Dhanhad-826004India

In this article upconversion luminescence of silver nanoparticles（AgNPs） coated NaYF4：Er3＋/Yb3＋phosphor nano-particles was *** prepared samples were characterized through various *** surface plasmon band is observed for prepared AgNPs by analyzing UV-vis measurements and is used to enhance the upconversion *** the upconversion measurement the emission bands are observed at 522,546,and 656 nm corresponding to the 2 H11/2→ 4115/2,4 s3/2→4 I15/2and 4 F9/2→4 I15/2 levels,*** upconversion emission intensity of the above bands is found to enhance for sample containing 1 mmol *** time of 4 s3/2 and 4F9/2 levels is found to decrease on coating of AgNPs and hence intensity enhancement is assumed due to the surface plasmon resonance（sPR） effect.

关键词： Upconversion phosphor surface plasmon resonance Decay time analysis CIE diagram Rare earths

spectroscopic investigations and luminescence spectra of sm3+ doped soda lime silicate glasses

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Journal of Rare Earths 2009年第5期27卷 773-780页

作者： Y.k. sharma s.s.L. surana R.k. singh Department of Physics Govt. Post Graduate College Rudrapur 263153 (U S Nagar) India Department of Physics J. N. V. University Jodhpur-342001 India Department of Physics Govt. Post Graduate College Rudrapur 263153 (U S Nagar) India

sm3+ doped soda lime silicate glasses co-doped with As2O3 were prepared and characterised by measuring their absorption spectra in UV-VIs/NIR regions and luminescence spectra in the visible region. Judd-Ofelt intensity parameters, Ωλ, were evaluated from the measured intensities of the various absorption bands. Ωλ parameters of these glasses were compared with the Ωλ parameters of other reported sm3+ glasses to study the bonding environment surrounding the sm3+ in the present glasses. Presence of [AsO4]3– tetrahedra in the second coordination sphere around the central sm3+ ion made these glasses less covalent as compared to other oxide glasses but the ratio Ω4/Ω6 of the 1.83 indicated them to be fairly stable. With the help of Ωλ parameters and luminescence data for various emission lines, radiative properties for different emission lines were calculated. The values of radiative properties indicated that 4G5/2→6H7/2 and 4G5/2→6H9/2 transitions responsible for orange luminescence might be used in the development of materials for LED's and other optical devices in the visible region.

关键词： rare earth glasses Judd-Ofelt theory absorption spectroscopy luminescence

Theoretical Approach to Change Blast Furnace Regime With Natural Gas Injection

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Journal of Iron and steel Research International 2013年第9期20卷 40-46页

作者： k s Abdel Halim Central Metallurgical Research and Development Institute(CMRDI)

The operation of blast furnace using natural gas and oxygen enriched blast （composite blast technology） is considered in many countries to be standard operation for a modern blast furnace particularly in certain countries with cheap and stable supply of natural gas. The theoretical flame temperature （TFT） of combustion and the degree of di-rect reduction of iron oxides （rd） are considered as the main controlling parameters of composite blast technology. The calculated values of these parameters are mainly dependent on the amount of air blast consumption. This amount of air blast is measured before entering into blast stoves, Actually, some of air blast is lost through valves of air stoves. Consequently, the real volume of air blast in the furnace is less than the recorded value by amounts of 5%-15% which is not considered in the estimation of rd and TFT. The purpose is to analyze the different methods for es-timation of air blast inside the blast furnaces and develop a theoretical model to calculate air blast eonsumption with high accuracy. Based on the calculation of air blast consumption, a complete roadmap is demonstrated to change the operation regime parameters of blast furnaces working on composite blast technology.

关键词： composite blast technique natural gas blast consumption theoretical flame temperature direct reduc-tion degree iron oxide

Nano-and micron-sized diamond genesis in nature:An overview

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Geoscience Frontiers 2018年第6期9卷 1849-1858页

作者： s.k.simakov LLC“ADAMANT”skolkovo Harchenko 19-A-7HSt.Petersburg194100Russia

There are four main types of natural diamonds and related formation processes. The first type comprises the interstellar nanodiamond particles. The second group includes crustal nano-and micron-scale diamonds associated with coals, sediments and metamorphic rocks. The third one includes nanodiamonds and microndiamonds associated with secondary alteration and replacing of mafic and ultramafic *** fourth one includes macro-, micron-and nano-sized mantle diamonds which are associated with kimberlites, mantle peridotites and eclogites. Each diamond type has its specific characteristics. Nanosized diamond particles of lowest nanometers in size crystallize from abiotic organic matter at lower pressures and temperatures in space during the stages of protoplanetary disk formation. Nano-sized diamonds are formed from organic matter at P-T exceeding conditions of catagenesis stage of lithogenesis. Micron-sized diamonds are formed from fluids at P-T exceeding supercritical water *** diamonds are formed from metal-carbon and silicate-carbonate melts and fluids at P-T exceeding 1150℃ and 4.5 GPa. Nitrogen and hydrocarbons play an important role in diamond *** role in the formation processes increases from macro-sized to nano-sized diamond *** of nitrogen atoms into the diamond structure leads to the stabilization of micron-and nanosized diamonds in the field of graphite stability.

关键词： Diamond Nanodiamonds sediments Meteorites Mantle Organics

Effect of NO_3^--N Enrichment on seawater stress Tolerance of Jerusalem Artichoke (Helianthus tuberosus)

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Pedosphere 2008年第1期18卷 113-123页

作者： s.k.MEHTA College of Resources and Environmental sciences Nanjing Agricultural University

A hydroponic experiment with six treatments, i.e., 0% seawater （control）, 10% seawater, 25% seawater, 0% seawater ＋ N （7.5 mmol L-1 NaNO3）, 10% seawater ＋ N （7.5 mmol L-1 NaO3）, and 25% seawater ＋ N （7.5 mmol L-1 NaNO3）, was carried out to study the effect of nitrogen addition on the growth and physiological and biochemical characteristics of Jerusalem artichoke （Helianthus tuberosus） seedlings under seawater stress. The 10% seawater stress treatment had the least effect on plant growth while at 25% seawater growth was significantly inhibited. The malondialdehyde content and electrolyte leakage in leaves under 10% seawater were similar to those of the control, but significantly higher under the 25% seawater stress. The activities of superoxide dismutase, peroxidase and catalase in the leaves increased concomitantly with increasing seawater concentration and time. Proline and soluble-sugars in the leaves and Na^＋, k^＋, and Cl- contents in shoots and roots increased significantly with the concentration of seawater increasing. Nitrogen addition resulted in increasing fresh and dry weights of shoots and roots compared with seawater treatment without N. Nitrogen supplementation also significantly enhanced the activities of antioxidant enzymes in leaves. Addition of N to seawater enhanced the contents of proline and soluble-sugars in the leaves and k^＋ and total-N in the aerial parts and roots of H. tuberosus, but it resulted in declined concentrations of Na^＋ and Cl- in the aerial parts and roots. Nitrogen addition ameliorated the toxicity of seawater by improving the antioxidative enzymes, accumulating of proiine and soluble-sugars, and altering the distribution of inorganic ions in H. tuberosus.

关键词： Helianthus tuberosus ions distributions malondialdehyde nitrate seawater stress

Merging bound states in the continuum in an open acoustic resonator

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science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 124-131页

作者： Lujun Huang Bin Jia Artem s.Pilipchuk sibo Huang Chen shen Almas F.sadreev Yong Li Andrey E.Miroshnichenko school of Physics and Electronic sciences East China Normal University Institute of Acoustics Tongji University L.V.kirensky Institute of Physics Department of Mechanical Engineering Rowan University school of Engineering and Technology University of New South Wales at Canberra

Bound states in the continuum （BICs） are perfectly localized resonances despite embedding in the continuum ***,an isolated BIC is very sensitive to the structure ***,we report merging acoustic BICs in a single open resonator,robust against the structure *** find that both symmetry-protected BIC and Friedrich-Wintgen BIC are sustained in a single coupled waveguide-resonator *** varying the height and length of the resonator,these two BICs move toward each other and merge into a single one at a critical *** to an individual BIC,the merged BIC is robust against fabrication error because its Q-factor is proportional to ΔL-4,whereΔL embodies the structure *** essence of this extraordinary phenomenon is perfectly explained by the two-and three-level approximations of the effective nonHermitian ***,we present direct experimental demonstrations of the moving and merging of BICs in a coupled 3D waveguide-resonator,which are evidenced by the vanishing of the linewidth of Fano resonance in the transmission *** results may find exciting applications in designing high-quality acoustic sources,sensors and filters.

关键词： acoustic resonances bound state in the continuum high-Q resonances

Novel functional association of rat testicular membrane-associated cytosolic glutathione s transferases and cyclooxygenase in vitro

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Asian Journal of Andrology 2005年第2期7卷 171-178,页

作者： s.Neeraja B.Ramakrishna A.s.sreenath G.V.Reddy P.R.k.Reddy P.Reddanna Department of Animal sciences School of Life SciencesUniversity of HyderabadHyderabad 500046India

Aim:To analyze the role of cytosolic glutathione s-transferases (cGsTs) and membrane-associated cytosolic GsTs (macGsTs) in prostaglandin biosynthesis and to evaluate the possible interaction between glutathione s-transferases (GsTs) and cyclooxygenase (COX) in ***:sDs-PAGE analysis was undertaken for characterization of GsTs,thin layer chromatography (TLC) to monitor the effect of GsTs on prostaglandin biosynthesis from arachi- donic acid (AA) and spectrophotometric assays were done for measuring activity levels of COX and ***: sDs-PAGE analysis indicates that macGsTs have molecular weights in the range of 25-28 *** a coupled assay involving GsTs,arachidonic acid and cyclooxygenase-1,rat testicular macGsTs produced prostaglandin E2 and F2~, while the cGsTs caused the generation of prostaglandin D2,E2 and F_(2α).In vitro interaction studies on GsTs and COX at the protein level have shown dose-dependent inhibition of COX activity by macGsTs and vice *** effect, however,is not seen with *** inhibitory effect of COX on macGsT activity was relieved with increasing concentrations of reduced glutathione (GsH) but not with 1-chloro 2,4-dinitrobenzene (CDNB).The inhibition of COX by macGsTs,on the other hand,was potentiated by ***:We isolated and purified macGsTs and cGsTs from rat testis and analyzed their involvement in prostaglandin *** studies reveal a revers- ible functional interaction between macGsTs and COX in vitro,with possible interactions between them at the GsH binding site of macGsTs.

关键词： glutathione s-transferase cyclooxygenase arachidonic acid glutathione prostaglandins

The Fibered Isomorphism Conjecture for Complex Manifolds

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Acta Mathematica sinica,English series 2007年第4期23卷 639-658页

作者： s.k.ROUsHON school of Mathematics Tata InstituteHomi Bhabha RoadMumbai 400 005India

In this paper we show that the Fibered Isomorphism Conjecture of Farrell and Jones, corresponding to the stable topological pseudoisotopy functor, is true for the fundamental groups of a class of complex manifolds. A consequence of this result is that the Whitehead group, reduced projective class groups and the negative k-groups of the fundamental groups of these manifolds vanish whenever the fundamental group is torsion free. We also prove the same results for a class of real manifolds including a large class of 3-manifolds which has a finite sheeted cover fibering over the circle.

关键词： Complex projective variety Complex surfaces Whitehead group Fibered isomorphism conjecture Negative k-groups