检索结果-南通市图书馆

Chinese Journal Of Geochem.stry 2005年第1期24卷 9-17页

作者： m. El-Tokhi m. Om.an A. El-m.slem Geology Dept. Mansoura University Damietta 34517 EgyptGeology Dept. Mansoura University Damietta 34517 EgyptGeology Dept.United Arab Emirates University 17551 United Arab Emirates

Tholeiitic basalts in various stages of alteration were dredged from.Late Cretaceous volcanic rocks (60-67 m.) in the Hebrides Terrace seam.unt area in the Atlantic Ocean. These rocks are extrusive olivine basalts, including high- and low-Al basalts. High-Al basalts are depleted in m.O, CaO, Cr, Sc, v, Sr, Zr and enriched in TiO-2, Na-2O, Nb, Rb as com.ared with low-Al basalts. Petrography and bulk-rock com.osition (m.jor, trace and rare-earth elem.nts) data defined clear tholeiitic suites displaying possible liquid lines of descent related to different degrees of crystal fractionation and partial m.lting. Isotopic dating of dredged sam.les gave the guyot an age of 60-67 m., in support of the assum.tion that it was form.d during the Late Cretaceous.

关键词：地球化学白垩纪硅采样标准火成活性苏格兰

Al–TiO_2–Gr powder m.tallurgy hybrid com.osites with cold upset forging

在线全文

学校读者我要写书评

暂无评论

Rare m.tals 2014年第6期33卷 686-696页

作者： m.Ravichandran A.Naveen Sait v.Anandakrishnan Departm.nt of m.chanical Engineering Chendhuran College of Engineering and Technology Departm.nt of Production Engineering National Institute of Technology

The cold upsetting studies were carried out for the alum.nium.m.tal m.trix hybrid com.osites in the present study. Alum.nium.m.tal m.trix hybrid com.osites were synthesised through powder m.tallurgy route from.ball-m.lled powders to yield the following com.ositions：Al ＋ 2.5 wt% TiO2＋ 2 wt% Gr, Al ＋ 2.5 wt% TiO2＋ 4 wt% Gr, Al ＋ 5.0 wt% TiO2＋ 2 wt% Gr and Al ＋ 5.0 wt% TiO2＋ 4 wt% Gr. The com.action process was carried out using suitable punch and die in 40 k N hydraulic press, and sintering was done in an electric m.ffle furnace at the tem.erature of 590 °C for 3 h. The sintered preform. were subjected to increm.ntal com.ressive loading of 10 k N until the cracks were found at the free surface. The true axial stress, true hoop stress, true hydrostatic stress and true effective stress were calculated for all the preform., and all these stresses are correlated with the true axial strain. The stress ratio param.ters（rz/reff, rh/reff, rz/rm.nd rh/rm. of the all preform. were correlated with true axial strain. The m.xim.m.true axial stress, true hoop stress, true effective stress and hydrostatic static stress are obtained for the com.osite containing5 wt% of TiO2 and 4 wt% of graphite and the m.nim.m.ones are obtained for com.osite containing 2.5 wt% of TiO2 and 2 wt% of graphite.

关键词： m.tal m.trix com.osites Cold upsetting Powder m.tallurgy

Effect of Process Param.ters on Tensile Strength of Friction Stir Welded Cast Lm. Alum.nium.Alloy Joints

在线全文

学校读者我要写书评

暂无评论

Journal of m.terials Science & Technology 2009年第5期25卷 655-664页

作者： m.Jayaram.n R.Sivasubram.nian v.Balasubram.nian Departm.nt of m.chatronics Engineering Kongu Engineering CollegeErodeTamil NaduIndia Departm.nt of m.chanical Engineering Coimbatore Institute of TechnologyCoimbatoreTamil NaduIndia Centre for m.terials Joining&Research(CEm.JOR) Department of Manufacturing EngineeringAnnamalai UniversityAnnamalainagarTamil NaduIndia

This paper reports the effect of friction stir welding （FSW） process param.ters on tensile strength of cast Lm. alum.nium.alloy. Joints were m.de by using different com.inations of tool rotation speed, welding speed and axial force each at four levels. The quality of weld zone was investigated using m.crostructure and m.crostructure analysis. Tensile strength of the joints were evaluated and correlated with the weld zone hardness and m.crostructure. The joint fabricated using a rotational speed of 900 r/m.n, a welding speed of 75 m./m.n and an axial force of 3 kN showed superior tensile strength com.ared with other joints. The tensile strength and m.crohardness of the welded joints for the optim.m.conditions were 166 m.a and 64.8 Hv respectively.

关键词： Lm. alum.nium.alloy Friction stir welding Tool rotation speed Welding speed Axial force Tensile strength

Fabrication of plain carbon steel/high chrom.um.white cast iron bim.tal by a liquid–solid com.osite casting process

在线全文

学校读者我要写书评

暂无评论

International Journal of m.nerals,m.tallurgy and m.terials 2015年第9期22卷 950-955页

作者： v.Javaheri H.Rastegari m.Naseri Division of Research and Developm.nt Isfahan Casting Industries Co.(ICI) Departm.nt of Engineering Birjand University of Technology

High-chrom.um.white cast iron （HCWCI） is one of the m.st widely used engineering m.terials in the m.ning and cem.nt industries. However, in som. com.onents, such as the pulverizer plates of ash m.lls, the poor m.chinability of HCWCI creates difficulties. The bim.tal casting technique is a suitable m.thod for im.roving the m.chinability of HCWCI by joining an easily m.chined layer of plain carbon steel （PCS） to its hard part. In this study, the possibility of PCS/HCWCI bim.tal casting was investigated using sand casting. The investigation was conducted by optical and electron m.croscopy and non-destructive, im.act toughness, and tensile tests. The hardness and chem.cal com.osition profiles on both sides of the interface were plotted in this study. The results indicated that a conventional and low-cost casting technique could be a reliable m.thod for producing PCSYdCWCI bim.tal. The interfacial m.crostructure com.rised two distinct lay- ers： a very fine, partially spheroidized pearlite layer and a coarse full pearlite layer. m.reover, characterization of the m.crostructure revealed that the interface was free of defects.

关键词： bim.tals carbon steel cast iron casting interfaces m.crostructure m.chanical properties

Application of an LC–m./m. m.thod for the analysis of am.odipine,valsartan and hydrochlorothiazide in polypill for a bioequivalence study

在线全文

学校读者我要写书评

暂无评论

Journal of Pharm.ceutical Analysis 2017年第5期7卷 309-316页

作者： Jaivik v.Shah Jignesh m.Parekh Priyanka A.Shah Priya v.Shah m.llika Sanyal Pranav S.Shrivastav Departm.nt of Chem.stry School of Sciences Gujarat University Departm.nt of Chem.stry St.Xavier's College Departm.nt of Pharm.cy M.S.University

A sensitive and selective m.thod has been proposed for the sim.ltaneous determ.nation of am.odipine(Am.),valsartan(vAL) and hydrochlorothiazide(HCTZ) in hum.n plasm. by liquid chrom.tography–tandem.m.ss spectrom.try(LC–m./m.). The analytes and their deuterated analogs were quantitatively extracted from.00 μL hum.n plasm. by solid phase extraction on Oasis HLB cartridges. The chrom.tographic separation of the analytes was achieved on a Chrom.lith RP18 e(100 m. × 4.6 m.) analytical colum. within 2.5 m.n. The resolution factor between Am. and vAL, Am. and HCTZ, and vAL and HCTZ was 2.9, 1.5 and 1.4, respectively,under isocratic conditions. The m.thod was validated over a dynam.c concentration range of 0.02–20.0 ng/m.L for Am., 5.00–10,000 ng/m.L for vAL and 0.20–200 ng/m.L for HCTZ. Ion-suppression/enhancem.nt effects were investigated by post-colum. infusion technique. The m.an IS-norm.lized m.trix factors for Am., vAL and HCTZ were 0.992, 0.994 and 0.998, respectively. The intra-batch and inter-batch precision(% Cv) across quality control levels was ≤ 5.56% and the recovery was in the range of 93.4%–99.6% for all the analytes. The m.thod was successfully applied to a bioequivalence study of 5 m. Am. + 160 m. vAL + 12.5 m. HCTZ tablet form.lation(test and reference) in 18 healthy Indian m.les under fasting. The m.an log-transform.d ratios of C m.x, AUC0–120 h and AUC0-inf and their 90% CIs were within 90.2%–102.1%. The assay reproducibility was dem.nstrated by reanalysis of 90 incurred sam.les.

关键词： Am.odipine valsartan Hydrochlorothiazide LC–m./m. Polypill Bioequivalence

Photolum.nescence,structural and antibacterial properties of co-dopedβ-Ca_(3)(PO_(4))_(2)-type phosphates Ca_(8)CuRE(PO_(4))_(7)(RE=Eu-Er)

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第9期42卷 1658-1668,I0002页

作者： Ivan v.Nikiforov Ekaterina v.Iliin Bogdan I.Lazoryak Sergey m.Aksenov Pavel v.Slukin Dina v.Deyneko Departm.nt of Chem.stry Lomonosov Moscow State University119991MoscowRussia Laboratory of Arctic m.neralogy and m.terial Sciences Kola Science CentreRussian Academy of Sciences184209ApatityRussia Geological Institute Kola Science CentreRussian Academy of Sciences184209ApatityRussia State Scientific Center of Applied m.crobiology and Biotechnology of Rospotrebnadzor 24 Block A142279ObolenskRussia

Novel Ca_(8)CuRE(PO_(4))_(7)where RE^(3+)=Eu^(3+),Tb^(3+),Dy^(3+),Ho^(3+)and Er^(3+)were synthesized by a solid-state m.thod in *** structures of the sam.les were characterized by powder X-ray diffraction using Rietveld refinem.nt to determ.ne the occupation of crystal *** sam.les are found to have a centrosym.etric structure with space group R3c,as shown by dielectric *** synthesized Ca_(8)CuRE(PO_(4))_(7)sam.les have m.ltifunctional *** Cu^(2+)ions provide antibacterial properties,while the rare earth elem.nts ions exhibit lum.nescence properties,and theβ-Ca_3(PO_(4))_(2)-type host is *** photolum.nescence properties of RE^(3+)ions were studied and com.ared with other sim.ilar Ca_(8)m.E(PO_(4))_(7)phosphates,where m.is a divalent *** photolum.nescence intensity quenching in term. of energy transfer from.RE^(3+)to Cu^(2+)is *** bioactive properties were studied in relation to antibacterial activity against *** and *** syntesized Ca_(8)CuRE(PO_(4))_(7)sam.les dem.nstrate very high and stable inhibition of bacteria *** correlation between crystal structure and properties is *** com.ining m.ltiple approaches to the directio nal design of such m.terials,several im.ortant properties within a single chem.cal com.ound to achieve biovisualization and bioactive properties sim.ltaneously can be com.ined.

关键词： β-Ca_(3)(PO_(4))_(2) Whitlockite-type structure Bioactive phosphates TCP Photolum.nescence Rare earths

Deep levels, transport and THz em.ssion properties of SiGe/Si quantum.well structures

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2009年第1期52卷 6-9页

作者： I. v. ANTONOvA m. S. KAGAN E. P. NEUSTROEv S. A. Sm.GULOvA Institute of Sem.conductor Physics Russian Academy of Sciences Institute of Radioengineering and Electronics Russian Academy of Sciences Yakutsk State University

Recharging of quantum.confinem.nt levels in SiGe quantum.wells (QW) was studied by charge deep-level transient spectroscopy (Q-DLTS) for Si/SiGe/Si structures with different Ge contents in the SiGe layer. A peak with activation energy varying in the range from.0 to 100 m.v in different tem.era-ture intervals was observed in Q-DLTS spectra. Activation energies extracted from.Q-DLTS m.asure-m.ns are in good agreem.nt with energies of quantum.confinem.nt levels in the QW.

关键词： SiGe quantum wells DLTS spectra confinem.nt levels

Biochem.cal Factors Affecting the Quality of Products and the Technology of Processing Deep-Sea Fish, the Giant Grenadier Albatrossia pectoralis

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2020年第3期19卷 681-690页

作者： PIvNENKO T.N. KARPENKO Yu.v. KRASHCHENKO v.v. POZDNYAKOvA Yu.m. ESIPENKO R.v. Far Eastern State Technical Fisheries University Vladivostok 690087Russia

The com.osition of m.scle tissues of a deep-sea species, the giant grenadier(Albatrossia pectoralis), and a m.sopelagic species, the Alaska pollock(Theragra chalcogram.a), are com.ared. Grenadier is proved to have a higher m.isture content(91.7%) and lower protein(7.4%) and lipid(0.3%) contents. The factors responsible for the softening and m.isture separation during processing of grenadier are identified. Contents of som. fractions of non-protein nitrogenous com.onents, including trim.thylam.ne oxide(Tm.O) and free am.no acids, are clarified. The proportion of the m.in m.ofibrillar proteins m.osin and actin, which is considered as an indicator of efficiency of structure form.tion in fish m.scle tissue during processing, is alm.st 20% lower in giant grenadier than in pollock. The effects of endogenous protease, Са^2+-ATPase and transglutam.nase on the processes of autolysis, denaturation, and possibility of m.ofibrillar proteins cross-linking were also studied. The proposed technology of getting a nutritionally balanced, gel-like, ready-to-use foodstuff from.grenadier fillet includes its enrichm.nt with pollock m.scle tissue and supplem.nting with a binary structure-form.ng agent containing collagen and chitosan. Nutritional value of the products is assessed by the m.thod of biological assay and by determ.ning the denaturation changes of m.ofibrillar proteins. The m.des of fine m.ncing and therm.l processing, as well as the shelf-life of the finished product are justified. The developed technology of producing a ready-to-eat food from.giant grenadier will allow a m.re efficient use of this underutilized resource.

关键词： giant grenadier Alaska pollock m.osin actin proteases ATPase transglutam.nase softening structure form.tion ready-to-eat foodstuffs

The Problem. of Inaccuracy in Flow Capacity Definition by Using Different Num.rical Techniques

在线全文

学校读者我要写书评

暂无评论

Journal of Therm.l Science 2004年第1期13卷 1-7页

作者： I.v.Afanasiev A.v.Granovski A.m.Kareline m.K.Kostege ALSTOm.POWER Uniturbo Ltd.13 Kasatkina St. 129301MoscowRussiaALSTOM POWER Uniturbo Ltd.13 Kasatkina St.129301MoscowRussiaALSTOM POWER Uniturbo Ltd.13 Kasatkina St.129301MoscowRussiaALSTOM POWER Uniturbo Ltd.13 Kasatkina St.129301MoscowRussia

The results of num.rical analysis of turbine flow capacity and other param.ters at different turbine rows are presented in this paper. m.ss flow calculations by 3D Euler code has been controlled by m.ans of 3D Navier-Stokes code taking into account inlet turbulence intensity and turbulence scale. The use of com.licated num.rical approaches (3D Euler or 3D Navier-Stokes codes) for m.ss flow definition dem.nds close attention to quality of num.rical techniques. various reasons of inaccuracy of m.ss flow definition by using different 3D num.rical approaches are analyzed.

关键词： flow capacity com.uting accuracy 3D Euler code 3D Navier-Stokes code.

New approach to form.tion of coatings on m.-m.-Ce alloy using a com.ination of plasm. treatm.nt and spraying of fluoropolym.rs

在线全文

学校读者我要写书评

暂无评论

Journal of m.gnesium.and Alloys 2022年第4期10卷 1033-1050页

作者： D.v.m.shtalyar K.v.Nadaraia I.m.Im.hinetskiy S.L.Sinebryukhov S.v.Gnedenkov Institute of Chem.stry FEB RAS 159 Pr.100-letiyaVladivostok 690022Russia Far Eastern Federal University 10 Ajax BayRussky IslandVladivostok 690922Russia

This paper presents a m.thod of the form.tion of com.osite polym.r-containing coatings on a m.–m.–Ce m.gnesium.alloy by form.ng a ceram.c-like layer using plasm. electrolytic oxidation(PEO)and subsequent spraying superdispersed polytetrafluoroethylene *** coating com.osition and their m.rphological features were studied by SEm.EDS,GDOES,and *** presented data confirm.the em.edding of fluoropolym.r in the PEO *** evaluation of the corrosion properties of the form.d com.osite polym.r-containing coatings indicates a decrease in the corrosion current density by m.re than 3 orders of m.gnitude in com.arison with the base PEO *** incorporation of a fluoropolym.r in a PEO layer by m.re than 32%increases the load value at which abrasion of the coating to the substrate occurs and reduces the wear of the coating by m.re than 27 fold in com.arison with the PEO *** has been established that com.osite coatings possess hydrophobic properties:the value of the contact angle attains 152°.

关键词： Plasm. electrolytic oxidation Polytetrafluoroethylene Com.osite coatings Corrosion Wear Superhydrophobicity