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Petrology and geochemical framework of dolerites dykes of Temte, North Cameroon, Central Africa

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Acta Geochimica 2021年第3期40卷 287-299页

作者： m.mey Atour J.m.Bardintzeff A.Fagny mefire O.F.Nkouandou R.Tchameni A.Dinamou Department of Earth Sciences Faculty of SciencesUniversity of NgaoundereP.O.Box 454NgaoundereCameroon Sciences de la Terre VolcanologiePlanetologieUMR CNRS 8148 GEOPSbat.504Universite Paris-Saclay91405 OrsayFrance Department of mineral Engineering Chemical Engineering and Mineral Industry SchoolUniversity of NgaounderanalysesP.O.Box 454NgaoundereCameroon

The Temtebasement in North Cameroon is crosscut by dyke swarms with N 20°–40°trending,including dykes 15–30 m wide,up to 3 *** rocks exhibit intersertal to sub-ophitic *** microprobe analyses identified diopside,augite,pargasite,biotite,Ti-magnetite,plagioclase,and ***-rock ICP-mS and ICP-AES chemical analyses showed compositions of basaltic andesite,basaltic trachyandesite and trachyandesite in *** differentiation was likely governed by fractional crystallization associated with limited fluid *** lavas could have been moderately contaminated by crustal materials during feeding of local cracks through turbulent magma *** geochemical diagrams and immobile trace and REE element ratios show that the mantle source of Temtedolerites was a deep phlogopitebearing EmII mantle component and has undergone moderate to high partial melting *** of fieldwork and analytical data with previous results evidence the Temtedolerite dyke swarms as fingerprints of crustal extension accompanying regional uplift in an active continental margin when early rifting led to the formation of the Poli marginal basin.

关键词： Dolerite Dyke Temte Poli Cameroon Central Pan-African Fold Belt

Angular Dependence of Lateral and Levitation Forces in Asymmetric Small magnet/Superconducting Systems

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Chinese Physics Letters 2007年第9期24卷 2700-2703页

作者： H. m. Al-Khateeb m. K. Alqadi F. Y. Alzoubi N. Y. Ayoub Department of Physics Jordan University of Science and Technology Irbid Jordan School of Applied Natural Sciences German Jordanian University Amman Jordan

The dipole-dipole interaction model is used to calculate the angular dependence of lateral and levitation forces on a small permanent magnet and a cylindrical superconductor in the meissner state lying laterally off the symmetric axis of the cylinder. Under the assumption that the lateral displacement of the magnet is small compared with the physical dimensions of the system, we obtain analytical expressions for the lateral and levitation forces as functions of geometrical parameters of the superconductor as well as the height, the lateral displacement and the orientation of magnetic moment of the magnet. The effect of thickness and radius of the superconductor on the levitation force is similar to that for a symmetric magnet/superconducting cylinder system, but within the range of lateral displacement. The splitting in the levitation force increases with the increasing angle of orientation of the magnetic moment of the magnet. For a given lateral displacement of the magnet, the lateral force vanishes when the magnetic moment is perpendicular to the surface of the superconductor and has a maximum value when the moment is parallel to the surface. For a given orientation of the magnetic moment, the lateral force has a linear relationship with the lateral displacement. The stability of the magnet above the superconducting cylinder is discussed in detail.

关键词： THIN SUPERCONDUCTING DISKS mEISSNER STATE mAGNETIC-LEVITATION PERmANENT-mAGNET CERAmICS CYLINDER SAmPLE

Analysis and Assessment of Wind Energy Potential of Al-Hodeidah in Yemen

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Computers, materials & Continua 2021年第11期69卷 1995-2011页

作者： Fahd N.Al-Wesabi murad A.Almekhlafi mohammed Abdullah Al-Hagery mohammad Alamgeer Khalid mahmood majdy m.Eltahir Ali m.Al-Sharafi Amin m.El-Kustaban Department of Computer Science King Khalid UniversityMuhayel AseerKingdom of Saudi Arabia Faculty of Computer and IT Sana’a UniversitySana’aYemen Department of Electrical Engineering–Communication Engineering Sana’a UniversityYemen Department of Computer Science College of ComputerQassim UniversitySaudi Arabia Department of Information Systems King Khalid UniversityMayahel AseerKSA Department of Computer Science College of Computers and Information TechnologyUniversity of BishaKSA Department of Electronic Faculty of EngineeringUSTSana’aYemen

Renewable energy is one of the essential elements of the social and economic development in any civilized *** use of fossil fuels and the non-renewable form of energy has many adverse effects on the most of *** the high potential of renewable energy sources in Yemen and the absence of similar studies in the region,this study aimed to examine the wind energy potential of Hodeidah-Yemen Republic by analyzing wind characteristics and assessment,determining the available power density,and calculate the wind energy extracted at different *** average wind speed of Hodeidah was obtained only for the data currently available for the five years 2005–2009(due to the current economic and the political situation in Yemen).The results show that the average wind speed in the five years is(25.2 W/m2 at 10 m,93.9 W/m2 at 30 m,and 173.5 W/m2 at 50 m).The average yearly wind power density(25.2 W/m2 at 10 m,93.9 W/m2 at 30 m and 173.5 W/m2 at 50m),and the average yearly energy density(220.8 KWh/m2/year at 10 m,822.6 KWh/m2/year at 30 m and 1519.9 KWh/m2/year at 50 m).This research is a preliminary assessment of the potential of wind energy in Hodeidah,which provides useful information for developing wind energy and an efficient wind *** to the International Wind Energy Rating criteria,the region of Hodeidah falls under‘Class 2’and is classified as‘marginal’for most of the year.

关键词： Energy potential wind speed weibull distribution wind power density

Central retinal artery resistive index and optical coherence tomography in assessment of glaucoma progression

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International Journal of Ophthalmology(English edition) 2015年第2期8卷 305-309页

作者： Ahmed F.Abdel Ghany Samer m.Botros Tamer m.El-Raggal Department of Radiodiagnosis Faculty of Medicine Ain Shams University Department of Ophthalmology Faculty of Medicine Ain Shams University

AIm: To assess the relation between central retinal artery(CRA) resistive index(RI) and retinal nerve fiber thickness measured by optical coherence tomography(OCT) in assessment of disease progress in cases of open angle ***: Twenty-three patients with diagnosed open angle glaucoma were included in this study. They were examined by colored duplex ultrasonography of CRA with estimation of RI of CRA and ophthalmic artery(OA)with estimation of CRA/OA RI ratio as well as OCT measurement of the average retinal nerve fiber layer(RNFL) thickness in order to assess the disease ***: There was strong inverse relation between the increased RI in CRA as well as the increased CRA/OA RI ratio and the decrease in average RNFL thickness in cases of open angle ***: Assessment of CRA RI can indirectly assess the vascular changes associated with glaucoma and can assess the degree of retinal atrophy helping in evaluating prognosis thus guiding the choice of treatment.

关键词： glaucoma optical coherence tomography central retinal artery duplex ophthalmic artery resistive index

Ultrasound-enhanced milling in the synthesis of phase-pure, highly crystalline ZnAl-layered double hydroxide of low Zn（II） content

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Particuology 2016年第4期14卷 29-33页

作者： m.Szabados Cs. Bus m. Adok-Sipiczki Z. Konya A. Kukovecz P. Sipos I. Palinko Department Qf Organic Chemistry University of Szeged Domter 8 Szeged H-6720 Hungary material and Solution Structure Research Group Institute of Chemistry University of Szeged Aradi Vertanflk tere 1 Szeged H-6720 Hungary Department of Applied and Environmental Chemistry University of Szeged Rerrich B. ter 1 Szeged H-6720. Hungary mTA-SZTE Reaction Kinetics and Surface Chemistry Research Croup Rerrich B ter 1 Szeged H-6720 Hungary mTA-SZTE "Lendulet" Porous Nanocomposites Research Group Rerrich B. ter 1 Szeged H-6720 Hungary Department of lnorganic and Analytical Chemistry University of Szeged Domter 7 Szeged H-6720 Hungary

Dry milling followed by ultrasonic irradiation in the presence of small amounts of aqueous NaOH, was used to synthesise ZnAl-layered double hydroxide （LDH）. The synthetic conditions were optimised and the Zn（OH）2, ZnO, and AI（OH）3 contaminants were removed by rinsing with aqueous NH3 solution from the sample prepared in the optimum conditions. Thus, phase-pure ZnAl-layered double hydroxide was obtained with high crystallinity. All materials produced during the syntheses were characterised by X- ray diffractometry, and a rose-like morphology was observed by scanning electron microscopy in the phase-pure sample. By changing the initial Zn/Al ratio, it was revealed that an LDH with low zinc content was always formed, probably through substitution of some of the Zn2. ions by AI3. ions in the gibbsite lattice.

关键词： ZnAl-layered double hydroxide Dry milling Ultrasonic irradiation

New doubly-periodic solutions for the new integrable non local modified KdV equation

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Journal of Ocean Engineering and Science 2017年第4期2卷 245-247页

作者： S.Shamseldeen m.S.Abdel Latif A.A.Hamed H.m.Nour mathematics and Engineering Physics Department Faculty of EngineeringMansoura UniversityPO 35516MansouraEgypt

In this paper,new doubly-periodic solutions will be found for a new integrable nonlocal modified Korteweg-de Vries equation(mKdV).We adopt a technique using a travelling wave transformation which results in different ... 详细信息

关键词： Nonlocal modified KdV equation Travelling waves Jacobi elliptic functions

Role of in-situ formed nano-and micro-fibrils in micro-fatigue resistance of bio-polyethylene

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Science China mathematics 2001年第S1期44卷 307-313页

作者： EJisheng m.J.Bevis Wolfson Centre for materials Processing Brunel UniversityUxbridgeUB8 3PH UK

In response to the need for the reduction of micro-debris generation in artificial humanjoints for extending the service life, a novel polymer process technology, SCORIm (shear con-trolled orientation injection moulding), was employed to manufacture a polyethylene compositereinforced by in-situ formed nano- and micro-fibrils. Tribological performance of a blend of ultrahigh molecular weight polyethylene (UHmWPE) and high density polyethylene (HDPE) was evalu-ated on a pin-on-disc wear machine. Results indicate a significant improvement in micro fatiguewear resistance compared with those moulded by a conventional injection moulding *** electron microscopy reveals that a micro-fibril structure forms as an in-situ fibre rein-forced composite using SCORIm while an aggregated structure occurs in specimens moulded byconventional technology. DSC analysis shows the occurrence of a second phase: shish kebabmicrostructure using SCORIm. Transmission electron microscopy reveals the transformation ofmicrostructure from randomly orientated lamella in the specimens moulded by conventional injec-tion moulding into nano-fibril shish kebab microstructure, which results in a significant reduction inthe possibility of the initiation and development of micro-cracks parallel to the contact surfacesusing SCORIm. Consequently, the formation of nano-fibril shish kebab and micro-fibril microstruc-ture by using the novel SCORIm technology results in a significant reduction in micro-fatigue whenusing the surface normal to the direction of the orientated molecular fibril microstructure as a con-tact surface.

关键词： nano-and micro-fibrils micro-fatigue resistance bio-polyethylene

Formation of ST Plasmas by ECH on LATE

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Plasma Science and Technology 2004年第4期6卷 2364-2366页

作者： m.Uchida T.maekawa H.Tanaka H.Igami T.Yoshinaga K.Katsuura m.Konno Kyoto University Kita shirakawa Oiwake-choKyoto 606-8502JapanKyoto UniversityKita shirakawa Oiwake-choKyoto 606-8502JapanKyoto UniversityKita shirakawa Oiwake-choKyoto 606-8502JapanKyoto UniversityKita shirakawa Oiwake-choKyoto 606-8502JapanKyoto UniversityKita shirakawa Oiwake-choKyoto 606-8502JapanKyoto UniversityKita shirakawa Oiwake-choKyoto 606-8502JapanKyoto UniversityKita shirakawa Oiwake-choKyoto 606-8502Japan

Experiments on formation of spherical tokamak (ST) plasmas by electroncyclotron heating (ECH) alone without a central OH solenoid have been carried out on LATE (LowAspect ratio Torus Experiments). By injecting a 2.45 GHz microwave pulse of 6.3 kW for 4 seconds, aplasma current is initiated and ramped up to I_p approx= 3 kA, and finally maintained for 1 secondby adjusting the external vertical field. magnetic measurements show that closed flux surfaces areformed and the last closed flux surface has an aspect ratio of A ～ 1.3 and an elongation of κ～1.3. The electron density measured by an interferometer is more than 1.5 x 10^(11) cm^(-3) whichexceeds twice of the plasma cut-off density, suggesting that electron cyclotron heating bymode-converted electron Bernstein waves may take place.

关键词： spherical tokamak non-inductive start-up electron cyclotron heating

Feasibility of developing composite action between concrete and cold-formed steel beam

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Journal of Central South University 2013年第12期20卷 3689-3696页

作者： S.O.Bamaga m.md.Tahir T.C.Tan S.mohammad N.Yahya A.L.Saleh m.mustaffar m.H.Osman A.B.A.Rahman Construction Research Centre (UTm-CRC) Faculty of Civil EngineeringUniversiti Teknologi Malaysia

Cold-formed steel structures are steel structure products constructed from sheets or coils using cold rolling, press brake or bending brake method. These structures are extensively employed in building construction industry due to their light mass, ductility by economic cold forming operations, favorable strength-to-mass ratio and other factors. The utilization of cold formed steel sections with concrete as composite can hugely reduce the construction cost. However, the use of cold formed steel members in composite concrete beams has been very limited. A comprehensive review of developments in composite beam with cold formed steel sections was introduced. It was revealed that employing cold-formed steel channel section to replace reinforcement bars in conventional reinforced concrete beam results in a significant cost reduction without reducing strength capacity. The use of composite beam consisting of cold-formed steel open or close box and filled concrete could also reduce construction cost. Lighter composite girder for bridges with cold-formed steel of U section was introduced. moreover, types of shear connectors to provide composite action between cold-formed steel beam and concrete slab were presented. However, further studies to investigate the effects of metal decking on the behavior of composite beam with cold-formed steel section and introduction of ductile shear connectors were recommended.

关键词： cold formed steel beam composite shear connection thin-wall composite girder