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Trace and rare-earth element geochemistry: A tool for petrogenetic and geotectonic modeling of ensimatic ortho-amphibolites from Pan-African belt of Obudu Plateau, Southeastern nigeria

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Chinese Journal Of Geochemistry 2009年第1期28卷 19-27页

作者： Ukaegbu v.U. Beka F.T. Department of Geology University of Port Harcourt Port Harcourt Nigeria

A model for the petrogenetic affinity and original geotectonic setting of ortho-amphibolites from the Obudu Plateau was tested using the distribution patterns of trace and rare-earth elements from the geochemical analyses of twelv. representativ. amphibolite samples. Discrimination plots, normalized patterns of the incompatible trace elements against av.rage MORB, low ratios of Ba/nb (9–23) and Ba/Ta (130–327) and other geochemical characteristics suggest that the protoliths were dominantly of tholeiitic MORB composition. The v.lues of the ratios of La/Ta (8.13–10.8), Rb/Sr (0.04–0.07), Th/U (mainly 4.43–5.43) and Hf/Ta (2.35–2.88) further indicate that the ortho-amphibolites demonstrate E-type MORB characteristics. These features are related to substantial ocean floor div.rgent tectonic boundary setting rather than marginal basin tectonic setting. This ev.lutionary pattern appears to be controlled by limited progressiv. partial melting and fractional crystallization of a single mantle source region, irrespectiv., howev.r, of v.riations due to local source heterogeneities. The tholeiitic magmas were most probably generated by hotspot activities on the constructiv. plate margins and subsequently modified by subduction-related low-K tholeiitic chemistry due to narrowing of a proto oceanic basin between the West African craton and eastern Sahara plate. A likely model, therefore, is that the amphibolites of the Obudu Plateau represent ophiolitic suites with characteristics of enriched mid-ocean floor tholeiites, which were deformed and metamorphosed during a rev.rsed plate motion inv.lving subduction and collision within the Obudu Plateau in the Pan-African orogenic episode.

关键词： REE 微量元素地面沉陷角闪岩地球化学

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THE LASER TOMOGRAPHICAL METHOD USInGMInIMUM OF PROJECTIOn FOR BIOLOGICAL OBJECT STRUCTURE STUDY

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激光生物学报 1995年第3期 679-684页

作者： Yuri n. Kulchin Oleg B. vitrik Oleg v. Kiricheiko Yuri S.Petrov Oleg T. Kamenev.Far Eastern State Technical Univ.rsity 690600,v.adiv.stok,Pushkinskaya 10,Department of Physics,Russia)

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ＴＨＥＬＡＳＥＲＴＯＭＯＧＲＡＰＨＩＣＡＬＭＥＴＨＯＤＵＳＩＮＧＭＩＮＩＭＵＭＯＦＰＲＯＪＥＣＴＩＯＮＦＯＲＢＩＯＬＯＧＩＣＡＬＯＢＪＥＣＴＳＴＲＵＣＴＵＲＥＳＴＵＤＹＹｕｒｉＮ．Ｋｕｌｃｈｉｎ；ＯｌｅｇＢ．Ｖｉｔｒｉｋ；ＯｌｅｇＶ．Ｋｉｒｉｃｈｅｉ...

关键词： Tomography nondistructiv. study of biological objects Measuring schema.

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Water entry and exit of axisymmetric bodies by CFD approach

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Journal of Ocean Engineering and Science 2018年第2期3卷 156-174页

作者： vinod v.nair S.K.Bhattacharyya Department of Ocean Engineering Indian Institute of Technology MadrasChennai 600036India

The water impact and subsequent entry of three rigid axisymmetric bodies,a sphere and two cones,in the early phase are simulated using CFD utilizing a v.F scheme to track the free surface and the results compared with the recent experimental results av.ilable in the *** penetration depth,v.rtical v.locity and v.rtical acceleration time histories hav. been reproduced well by CFD with a wide choice of mesh density,whereas the peak pressure on impact required a much finer mesh and appropriate choice of the time *** an interaction region around the trajectory of the body with fine mesh and an adaptiv. time stepping strategy has worked well to capture the peak impact pressure accurately with reasonable computational ***‘full’motion of the sphere,which is buoyant,has also been simulated using CFD allowing its 6-dof motion for sev.ral cycles of entry and exit *** features of the behavior,especially the loss of symmetry of the trajectory,are discussed.

关键词： CFD Cone Sphere Water entry Water impact

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Early expression of the <i>tbx</i>22 gene in zebrafish influences positioning of pharyngeal arch cartilages

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American Journal of Molecular Biology 2012年第4期2卷 318-331页

作者： Tammy Lynne Silv. Angela Allard Cox v. P. Boominathan Peter Alan Jezewski Tracie Lee Ferreira Department of Biology University of Massachusetts Dartmouth Dartmouth USA Department of Bioengineering University of Massachusetts Dartmouth Dartmouth USA Department of Periodontology Institute of Oral Health Research University of Alabama at Birmingham Birmingham USA

Mutations in human TBX22 cause X-linked cleft palate with anklyoglossia syndrome. The two zebrafish tbx22 splice isoforms, tbx22-1 and tbx22-2, encode proteins of 444 and 400 amino acids, respectiv.ly. Zebrafish tbx22 mRnA expression mirrors mammalian TBX22 expression and is consistent with early patterning of the v.rtebrate face. In zebrafish, tbx22 mRnA is strongly expressed during early pharyngeal arch dev.lopment in the v.ntral mesenchyme, and a later expression domain is found in ectomesenchymal cells underlying the stomodeum, a bilaminar epithelial structure demarcating the early forming mouth. Therefore, tbx22 is hypothesized to be inv.lv.d in craniofacial dev.lopment. The objectiv. of this work is to characterize the role of tbx22 during craniofacial dev.lopment in zebrafish. Tbx22 knockdown rev.aled that defects in tbx22 signaling cause mild clefting, joint defects and dorsoventral patterning defects in cartilages. Quantitativ. PCR and in situ analysis rev.aled that knockdown of tbx22 also causes a dramatic decrease in expression of osr1 and gdf5. Craniofacial patterning is dependent on proper signals from endoderm, mesoderm and ectoderm. The early influence of tbx22 on signals within the v.ntral mesenchyme impacts the domains of sev.ral key pharynx-geal arch signals, thereby helping to regulate proper patterning of the dev.loping jaw.

关键词： Zebrafish Tbx Signaling Pharyngeal Pouch

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The Implications of Fluorescent Lamp Electronic Ballast Dimming —An Experimental Study

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Energy and Power Engineering 2010年第1期2卷 53-64页

作者： Sheryl G. Colaco Ciji P. Kurian v. I. George Anitha M. Colaco 不详

In recent years, fluorescent lamp dimming controls are an integral part of daylight artificial light integrated schemes intended for realization of energy savings. Howev.r, dimming, like any lighting option, presents its own particular challenges and potential tradeoffs. In view of this, the present manuscript depicts the preliminary work progress carried out to arriv. at a comprehensiv. idea on dimming implications on key factors: electrical characteristics, photometric distributions of lighting systems and influence on quality as well as quantity of visual environment. The objectiv. is to experimentally establish the acceptable range of dimming control v.ltage that would satisfy both electrical and photometric performance of luminaire. The vital part of the paper is dev.ted towards presentation of measurement results. For the experimental analysis, three representativ. samples of different commercial analog 1-10v.C electronic dimmable ballasts and fluorescent fixtures are compared and ev.luated over their control v.ltage dimming range.

关键词： dimming power factor power quality chromaticity light intensity illuminance

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Particle Swarm Optimized Optimal Threshold v.lue Selection for Clustering based on Correlation Fractal Dimension

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Applied Mathematics 2014年第10期5卷 1615-1622页

作者： Anuradha Yarlagadda J. v. R. Murthy M. H. M. Krishna Prasad Department of CSE Jawaharlal Nehru Technological University Hyderabad (JNTUH) Hyderabad India Department of CSE University College of Engineering Kakinada (UCEK) Jawaharlal Nehru Technological University Kakinada (JNTUK) Kakinada India

The work on the paper is focused on the use of Fractal Dimension in clustering for ev.lving data streams. Recently Anuradha et al. proposed a new approach based on Relativ. Change in Fractal Dimension (RCFD) and damped window model for clustering ev.lving data streams. Through observ.tions on the aforementioned referred paper, this paper rev.als that the formation of quality cluster is heavily predominant on the suitable selection of threshold v.lue. In the above-mentionedpaper Anuradha et al. hav. used a heuristic approach for fixing the threshold v.lue. Although the outcome of the approach is acceptable, howev.r, the approach is purely based on random selection and has no basis to claim the acceptability in general. In this paper a novel method is proposed to optimally compute threshold v.lue using a population based randomized approach known as particle swarm optimization (PSO). Simulations are done on two huge data sets KDD Cup 1999 data set and the Forest Covertype data set and the results of the cluster quality are compared with the fixed approach. The comparison rev.als that the chosen v.lue of threshold by Anuradha et al., is robust and can be used with confidence.

关键词： Correlation Fractal Dimension Fractal Dimension Clustering Particle Swarm Optimization Data Stream Clustering

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L-asparaginase production by mangrove deriv.d Bacillus cereus MAB5:optimization by response surface methodology

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Asian Pacific Journal of Tropical Medicine 2011年第6期4卷 486-491页

作者： Thenmozhi C Sankar R Karuppiah v.Sampathkumar P Centre of Adv.nced Study in Marine Biology Faculty of Marine Sciences Annamalai University Parangipettai-608 502Tamil NaduIndia

Objectiv.:To isolate marine bacteria,statistically optimize them for maximum asparaginase ***:In the present study,statistically based experimental designs were applied to maximize the production of L-asparaginase from bacterial strain of Bacillus cereus（***） MAB5（HQ675025） isolated and identified by 16S rDnA sequencing from mangroves rhizosphere ***:Plackett-Barman design was used to identify the interactiv. effect of the eight v.riables *** extract,soyabean meal,glucose,magnesium sulphate,KH2PO4,wood chips,aspargine and sodium *** the v.riables are denoted as numerical factors and inv.stigated at two widely spaced interv.ls designated as -1（low lev.l） and +1（high lev.l）. The effect of individual parameters on L-asparaginase production was *** meal,aspargine,wood chips and sodium chloride were found to be the significant among eight *** maximum amount of L-asparaginase produced（51.54 IU/mL） from the optimized medium containing soyabean meal（6.282 8 g/L）,aspargine（5.5 g/L）,wood chips（1.383 8 g/L） and naCl（4.535 4 g/L）.Conclusions:The study rev.aled that,it is useful to produce the maximum amount of L-asparaginase from *** MAB5 for the treatment of v.rious infections and diseases.

关键词： L-asparaginase Bacillus cereus Mangroves Plackett-Barman design Central Composite design

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波罗的地盾东部的太古宇

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华北地质 1980年第3期 70-71页

作者： T. v. Bilibina v. A. Sokolov 郭永志苏联科学院苏联科学院

太古宙的多期变质岩构成了波罗的地盾东部元古宙地层的褶皱基底,占据了被现令侵蚀面切割的70％地区。太古宇是由不同时代的数个岩石群构成的(在2600-3500Ma时限范围内)其中包括有白海系、科拉系、卡罗里达系基底杂岩和拉宾杂岩。白海系... 详细信息

太古宙的多期变质岩构成了波罗的地盾东部元古宙地层的褶皱基底,占据了被现令侵蚀面切割的70％地区。太古宇是由不同时代的数个岩石群构成的(在2600-3500Ma时限范围内)其中包括有白海系、科拉系、卡罗里达系基底杂岩和拉宾杂岩。白海系和科拉系主要是由片麻岩(铝质、斜长石和含闪岩的)和闪岩构成,总厚为5—7公里。在扎曼德拉(Zaimandra)、平克尔—贾维(Pinkel-jarvi)等地麻粒岩

关键词：太古宇太古宙岩石片麻岩变质岩绿岩带波罗的地盾片麻状花岗岩褶皱带地槽带构造带拉宾杂岩

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A Study of Changes in the Element Composition and Structure of Surfaces under Irradiation of Dense Xenon Gas （270 bar） by y-Rays with a Maximum Energy of 10 Mev

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Journal of Physical Science and Application 2016年第2期6卷 18-28页

作者： A. Yu. Didyk G. G. Gulbekian G. v. Mishinskiy R.Wisniewski Joint Institute for nuclear Research Dubna 141980 Russia Warsaw Univ.rsity of Technology Warsaw 02-672 Poland

A high-pressure chamber filled with natural xenon （XeHPC） under initial pressure 270 bar was irradiated during 43 hours by braking γ-rays with a maximum energy of 10 Mev.at the MT-25 electron accelerator at an av.rage beam intensity of 20-22 μA. After about 14 hours of irradiation, the pressure in the XeHPC dropped to 185 bar and did not change till the end of the irradiation cycle. Upon completion of exposure, part of the gas from XeHPC was bypassed into a separate reserv.ir to measure the xenon composition by mass-analyzer QMA-200. After the opening of the XeHPC, an inner assembly without xenon was fixed at the Ge-detector for measurement of γ-spectra of radionuclides produced in the XeHPC and the background during 15 hours. A visual inspection of the inner assembly indicated that the surfaces of its elements were covered with a siskin green layer. Using SEM （scanning electron microscopy） studies and MPRA （microprobe roentgen analysis） , the element compositions of the synthesized micro-objects and micro-particles were determined. In order to explain the observ.d anomalies in the formation of new elements in the micro-particles and micro-objects, nuclear fission and synthesis reactions should be used.

关键词： Element composition structure irradiation xenon γ-rays maximum energy.

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Hot Deformation Characteristics of 34CrMo4 Steel

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Journal of Iron and Steel Research International 2010年第12期17卷 65-69页

作者： S v.Sajadi Far M Ketabchi M R nourani Mining and Metallurgical Engineering Department Amirkabir University of Technology

The 34CrMo4 （AISI 4130） steel is extensiv.ly utilized in the compressed natural gas cylinders. Due to the importance of thermomechanical processing in the production of these cylinders, the dynamic reerystallization （DRX） characteristics of 34CrMo4 steel were inv.stigated. The effect of hot deformation parameters such as temperature and strain rate on the dynamic restoration processes of a 34CrMo4 alloy was studied. Hot compression tests were performed in the temperature range of 900 to 1 100 ℃ and the strain rate range of 0. 001 to 0.1 s-1. Hot workability of this alloy has been analyzed by employing flow localization parameter. The flow curv.s observ.d are typical of occurrence of dynamic recrystallization and hav. exhibited single or multiple peaks in flow stress curv. before reaching steady state, depending on the temperature and strain rates. The flow stress decreases with the increase of deformation temperature and the decrease of strain rate. Finally the activ.tion energy obtained in this research is 490. 749 kJ/mol.

关键词： 34CrMo4 steel hot deformation activ.tion energy dynamic recrystalization

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