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Geochemistry and depositional env.ronment of fuchsite quartzites from Sargur Group,western Dharwar Craton,India

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Acta Geochimica 2024年第3期43卷 555-570页

作者： C.S.Sindhuja G.Harshitha C.Manikyamba K.S.v.Subramanyam CSIR(Council of Scientific and Industrial Research)-National Geophysical Research Institute(NGRI) Uppal RoadHyderabad 500007India

Meso-Neoarchean fuchsite quartzites are present in different stratigraphic positions of Dharwar Craton including the oldest(~3.3 Ga)Sargur Group of western Dharwar *** present study deals with the petro-graphic and geochemical characteristics of the fuchsite quartzites from the Ghattihosahalli belt to ev.luate their genesis,depositional setting and the enigma inv.lv.d in the ancient sedimentation *** major mineral assemblages include quartz,fuchsite,and feldspars along with accessory kyanite and *** geochemical com-positions are characterized by high SiO_(2),Al_(2)O_(3),low MgO,CaO,strongly enriched Cr(1326–6899 ppm),Ba(1165–3653 ppm),sr.46–210 ppm),v.107–868 ppm)and Zn(11–158 ppm)contents compared to the upper continental crust(UCC).The UCC normalized rare earth element(REE)patterns are characterized by depleted light REE[(La/Sm)UCC=0.33–0.95]compared to heav. REE[(Gd/Yb)_(UCC)=0.42–1.65]with conspicuous positiv. Eu-anomalies(Eu/Eu^(*)=1.35–18.27)characteristic of hydrothermal solutions ev.denced through the interlayered *** ov.rall major and trace element systematics reflect a combined mafic-felsic prov.nance and suggest their deposition at a passiv. continental margin *** comprehensiv.field,petrographic,and geo-chemical studies indicate that these quartzites are infiltrated by Cr-richfluids released during high-grade metamorphism of associated ultramafic *** Sargur and the subse-quent Dharwar orogeny amalgamated div.rse lithounits from different tectonic settings,possibly leading to the release of Cr-richfluids and the formation of fuchsite quartzite during or after the *** sug-gest a pre-existing stable crust prior to the Sargur Group and the link between orogenic ev.nts and v.rious mineral deposits in the Dharwar Craton.

关键词： Dharwar Craton Ghattihosahalli Fuchsite quartzite Prov.nance Depositional setting

Influences of diffusion bonding process parameters on bond characteristics of Mg-Cu dissimilar joints

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Transactions of Nonferrous Metals Society of China 2010年第6期20卷 997-1005页

作者： G. MAHENDRAN v. BALASUBR AMANIAN T. SENTHILv.LAN Department of Mechanical Engineering V.R.S. College of Engineering and Technology Centre for Materials Joining & Research (CEMAJOR) Department of Manufacturing Engineering Annamalai University Department of Mechanical Engineering Pondicherry Engineering College

In many circumstances,dissimilar metals hav. to be bonded together and the resulting joint interfaces must typically sustain mechanical and/or electrical forces without failure,which is not possible by fusion welding *** melting points of magnesium(Mg)and copper(Cu)hav. a significant difference(nearly 400℃)and this may lead to a large difference in the microstructure and joint performance of Mg-Cu ***,diffusion bonding can be used to join these alloys without much *** work analyses the effect of parameters on diffusion layer thickness,hardness and strength of magnesium-copper dissimilar *** experiments were conducted using three-factor,fiv.-lev.l,central composite rotatable design *** relationships were dev.loped to predict diffusion layer thickness,hardness and strength using response surface *** is found that bonding temperature has predominant effect on bond *** fabricated at a bonding temperature of 450℃, bonding pressure of 12 MPa and bonding time of 30 min exhibited maximum shear strength and bonding strength of 66 and 81 MPa, respectiv.ly.

关键词： diffusion bonding magnesium alloy copper alloy shear strength bonding strength diffusion layer thickness interface hardness

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汽车曲轴等温淬火可锻铸铁的发展

国外金属热处理 1989年第1期10卷 23-28页

作者： D.v.Kov.cs sr. 刘达武江西省科技情报研究所

引言近几年来,等温淬火可锻铸铁作为新型的工程材料脱颖而出。其性能可与锻造钢相媲美,在某种情况下甚至还优于锻造钢。把等温淬火可锻铸铁用于制造汽车零件比起用锻钢件来有许多优点,其中某些优点是设计和制造灵活、重量轻、抗弯强度... 详细信息

引言近几年来,等温淬火可锻铸铁作为新型的工程材料脱颖而出。其性能可与锻造钢相媲美,在某种情况下甚至还优于锻造钢。把等温淬火可锻铸铁用于制造汽车零件比起用锻钢件来有许多优点,其中某些优点是设计和制造灵活、重量轻、抗弯强度高、切削性好,以及制造成本可以大大降低。

关键词：汽车曲轴等温淬火可锻铸铁淬火

A Theoretical Study of the Pressure for Liquid Metal Infiltration of a Fiber Preform

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Journal of Materials Science & Technology 1995年第1期11卷 75-78页

作者： YU, sr.HE, ZM

A theoretical model has been established for calculating the infiltration pressure of metal melt into the preform of ceramic fibers according to the basic principle of hydromechanics. There are three forces acting on the infiltration process in the model, i.e. v.scous friction, capillary force, and grav.ty. The effects of the v.lume fraction of fibers (v.f) and infiltrating depth on the infiltration pressure are discussed. the results show that the infiltration pressure increases with tile increase of fiber v.lume fraction and infiltration depth. There is a linear relationship between infiltration pressure and infiltration depth. The effect of grav.ty on the infiltration pressure can be ignored.

关键词： MATRIX COMPOSITES

Metasurfaces: physics and applications in wireless communications

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National Science Rev.ew 2023年第8期10卷 48-63页

作者： v.sileios G. Ataloglou Sajjad Tarav.ti George v. Eleftheriades The Edward S.Rogers sr.Department of Electrical and Computer Engineering University of Toronto Clarendon Laboratory Department of Physics University of Oxford

The ev.r increasing number of wireless dev.ces and systems has led to a crowded spectrum and increased the demand for v.rsatile and multi-functional wireless apparatuses. Recently, metasurfaces hav. been explored as a prominent technological solution to the current paradigm of spectrum scarcity by opportunistically sharing the spectrum with v.rious users. In general, metasurfaces are passiv./dynamic,ultra-compact, multi-functional and programmable structures that are capable of both reciprocal and nonreciprocal signal-wav. transmissions. The controllability and programmability of such metasurfaces are gov.rned through DC bias and occasionally a radio-frequency modulation applied to the activ. components of the unit cells of the metasurface, e.g. diodes and transistors. This article ov.rv.ews some of the recently proposed passiv. and dynamic metasurfaces and shows that metasurfaces can enhance the performance of wireless communication systems thanks to their unique physical features such as real-time signal coding,nonreciprocal-beam radiation, nonreciprocal beamsteering amplification and adv.nced pattern-coding multiple access communication.

关键词： metasurface beamsteering beamforming wireless communication time modulation wav. engineering

Heav. metal stress induced hyperglycemia in blue swimmer crab, Portunus pelagicus

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Acta Oceanologica Sinica 2018年第5期37卷 47-53页

作者： SARAv.NAN R. SUGUMAR v. BEEMA MAHIN M.I. Department of Oceanography and Coastal Area Studies Alagappa UniversityThondi Campus

The study was to find out the effect of cadmium and mercury on lev.ls of hemolymph glucose, crustacean hyperglycemic hormone（CHH） and hepatopancreas glycogen in the blue swimmer crab Portunus pelagicus. The experiments were performed in both intact and eyestalk ablated crabs. Quantification of CHH was done by the indirect ELISA with the aid of primary anti-Carcinus maenas-CHH antibody. Higher glucose concentration was observ.d on exposure to 8×10^–6 of cadmium（（825.6±5.42） μg/m L） and 6×10^–6 of mercury（（90.5±6.25） μg/m L）after 48 h and 24 h respectiv.ly. Higher lev.l of hemolymph glucose was observ.d in eyestalk intact crabs on exposure to cadmium and mercury than eyestalk ablated crabs. Decrease in the lev.ls of CHH was observ.d in both eyestalk intact and ablated crabs on heav. metal exposure. Decline of the hepatopancreas glycogen lev.l was also witnessed with the exposure to heav. metal, which v.lidated its utilization in the production of glucose. Thus this study brings to light, the v.riations in hemolymph glucose, CHH and hepatopancreas glycogen on heav. metal stress. These carbohydrate metabolites can be used as biomarkers in assessing heav. metal contamination in water bodies.

关键词： crustacean hyperglycemic hormone cadmium mercury decapod crustaceans blue swimmer crab

Effects of v.riable fluid properties on the thin film flow of Ostwald-de Waele fluid ov.r a stretching surface

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Journal of Hydrodynamics 2013年第1期25卷 10-19页

作者： v.JRAv.LU K. PRASAD K. v. RAJU B. T. Department of Mathematics Department of Mechanical Material and Aerospace Engineering University of Central Florida Department of Mathematics Central College Campus Bangalore University

We inv.stigate, in this paper, the effects of thermo-physical properties on the flow and heat transfer in a thin film of a power-law liquid ov.r a horizontal stretching surface in the presence of a v.scous dissipation. The fluid properties, namely the fluid v.scosity and the fluid thermal conductiv.ty, are assumed to v.ry with temperature. Using a similarity transformation, the gov.rning partial differential equations with a time dependent boundary are conv.rted into coupled non-linear Ordinary Differential Equations （ODEs） with v.riable coefficients. Numerical solutions of the coupled ODEs are obtained by a finite difference scheme known as the Keller-box method. Results for the v.locity and temperature distributions are presented graphically for different v.lues of the pertinent parameters. The effects of unsteady parameter on the skin friction, the wall temperature gradient and the film thickness are presented and analyzed for zero and non-zero v.lues of the temperature-dependent thermo-physical properties. The results obtained rev.al many interesting features that warrant further study on the non-Newtonian thin film fluid flow phenomena, especially the shear-thinning phenomena.

关键词： Thin film flow v.riable fluid properties v.scous dissipation finite difference method

An unreported complication of acute pancreatitis

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World Journal of Gastroenterology 2007年第27期13卷 3756-3757页

作者： G Muthukumarasamy v.Shanmugam sr.Yule R Rav.ndran Department of Surgery Aberdeen University and Aberdeen Royal Infirmary Foresterhill Aberdeen Scotland AB25 2ZN United Kingdom Department of Surgery Lincoln County Hospital Lincoln England LN2 5QY United Kingdom Department of Radiology Aberdeen University and Aberdeen Royal Infirmary Foresterhill Aberdeen Scotland AB25 2ZN United Kingdom

Acute pancreatitis constitutes 3% of all admissions with abdominal pain. There are reports of osteal fat necrosis leading to periosteal reactions and osteolytic lesions following sev.re pancreatitis, particularly in long bones. A 54-year-old man was admitted to our hospital with acute pancretitis, who later dev.loped spinal discitis secondary to necrotizing pancreatitis. He was treated conserv.tiv.ly with antibiotics and after a month he recov.red completely without any neurological deficit. This case is reported for its unusual and unreported spinal complications after acute pancreatitis.

关键词： Acute pancreatitis Spinal osteomyelitis Lumbar discitis Fat necrosis Necrotizing pancreatitis

The Role of the Size Effect on the Drying of Refractory Castables—How Its Under-standing Could Narrow the Gap between Laboratory Studies and Industrial Reality

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China's Refractories 2024年第2期33卷 35-40页

作者： M.H.MOREIRA H.PENG S.Dal PONT v.C.PANDOLFELLI Materials Engineering Department Federal University of São Carlos(UFSCar)São Carlos 13565-905Brazil Materials Innov.tion Elkem Silicon Products DevelopmentKristiansand 4621Norway CNRS Grenoble INP3SRUniversitéGrenoble AlpesGrenoble 38000France

Refractories hav. unique capabilities such as sustaining their shape and properties at extreme conditions such as the combination of high temperatures and thermal shock,contact with molten metals and slags and in some circumstances resistance to erosion from abrasiv. *** the large processing output of the heav. industries such as the cement and steel ones which both require high temperature processes,the refractories structures span v.rious meters and weight of sev.ral *** the water remov.l stage of hydraulic bonded castables in industrial sites takes hours(10-60 h)due to the risk of explosiv. spalling,efforts to mitigate it are commonly *** has prov.ded theoretical understanding of the general aspects of drying and important tools,such as the thermograv.metry analysis(TGA),for the design of refractory compositions with higher explosiv. spalling ***,the optimization of this process is still far from the industrial reality especially because the actual linings that require the drying are orders of magnitude larger than the samples considered in the laboratory ***,this study proposed the analysis of the sample v.lume effect on the water remov.l dynamics through TGA of high alumina castables with calcium aluminate ***φ5 cm×5 cm cylindrical samples were assessed in a laboratory scale equipment whereas macro TGA were carried out considering 20 cm×20 cm×20 cm and 30 cm×30 cm×30 cm cubic ***,the effect of polymeric fibers was also *** was found out that the different thermal gradients within the macro TGA samples resulted in an inflection on the sample’s heating rate and that the mass loss was affected by the v.lume considered,especially for the composition without *** findings highlight the requirement of carefully taking into consideration the different dimensional sizes and thermal gradients in the samples when analyzing and interpreting the laboratory studies,and

关键词： drying refractory castables size effect thermograv.metry analysis