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Characterization of some Egyptian serpentinites used as ornamental stones

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Chinese Journal Of Geochemistry 2008年第2期27卷 140-149页

作者： i.s. ismael M.s. Hassan Faculty of Education Suez Canal UniversitySuezEgypt Central Metallurgical Research & Development InstituteP.O. Box 87 HelwanCairoEgypt Faculty of Education Suez Canal UniversitySuez Egypt Central Metallurgical Research&Development InstituteP.O. Box 87 HelwanCairoEgypt

Egypt is characterized by wide occurrence of serpentinites, particularly in the central and southern parts of Eastern Desert. There are several cooperate factors that affect the serpentinites used as ornamental stones. These factors involve mineralogical characteristi.s.(including mineral composition and microstructure parameter), physical properti.s.and mechanical properti.s. Antigorite is an essential serpentinite mineral, with a minor amount of chrysotile. Talc, carbonates (magnesite and dolomite) and tremolite are the main associated minerals. Quality and quantity of associated minerals such as talc and carbonates (dolomite and magnesite) affect the properti.s.of serpentinites used as ornamental stones. Carbonates are resistant to weathering but suffer from acidic cleaning agents in interior use, whereas serpentinites with a high content of talc used on external faces undergo an increase in volume and a consequent rapid degradation. studied serpentinites are characterized by relatively small grain size with foliated texture, low water absorption, low porosity, and high abrasion resistance. in the samples studied the uniaxial compressive strength (UCs) vari.s.between 89 and 189 MPa, with an average of 152 MPa. According to the classification of Bell (1992), sample No. B8 is very high in strength while the rest high in strength.

关键词：蛇纹岩装饰材料水分吸收颗粒尺寸

Asymptotic and numerical study of a surface breaking crack subject to a transient thermal loading

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Acta Mechanica sinica 2006年第1期22卷 22-27页

作者： A.B. Movchan i.s. Jones ljmu.ac.uk Department of Mathematical sciencesUniversity of Liverpoo UK L69 3BX school of EngineeringJames Parsons BuildingJohn Moores UniversityByrom st.Liverpool UK. L3 3AF E-mail: i.s.jones

An asymptotic algorithm is applied to the problem of a finite, thermo-elastic solid containing a surface breaking crack, when the exterior surface is subjected to oscillatory thermal loading. This algorithm involves the study of a model problem. An analytical and numerical study of this model problem of a thermo-elastic half space containing a surface breaking crack and subjected to oscillatory thermal loading is presented. The crack surface is traction free. in particular, the amplitude of the stress intensity factor at the crack vertex is found as a function of the crack depth and the frequency of thermal oscillation.

关键词： Thermo-elasticity surface breaking crack Wiener-Hopf solution Weight function method

stability of fluid flow in a Brinkman porous medium–A numerical study

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Journal of Hydrodynamics 2014年第5期26卷 681-688页

作者： sHANKAR B.M. KUMAR Jai.s.iVAKUMARA i.s. 吴朝安 Department of Mathematics PES Institute of TechnologyBangalore 560 085India isRO satellite Centre Bangalore 560 017India Department of Mathematics Bangalore UniversityBangalore 560 001India Department of Mechanical Engineering The University of Hong Kong

The stability of fluid flow in a horizontal layer of Brinkman porous medium with fluid viscosity different from effective viscosity is investigated. A modified Orr-sommerfeld equation is derived and solved numerically using the Chebyshev collocation method. The critical Reynolds number Re, the critical wave number ac and the critical wave speed cc are computed for various values of porous parameter and ratio of viscositi.s. Based on these parameters, the stability characteristi.s.of the system are discussed in detail. streamlines are presented for selected values of parameters at their critical state.

关键词： Brinkman model Chebyshev collocation method hydrodynamic stability modified Orr-sommerfeld equation

FATiGUE LiVEs FOR iNDUCTiON HARDENED sHAFTs MATERiALs ACCORDiNG TO THE ENViRONMENTAL TEMPERATUREs

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Acta Metallurgica sinica(English Letters) 2005年第5期18卷 585-593页

作者： D.G. Lee K.C. Jang J.M. Kuk i.s. Kim Korea i.s.itute of industrial Technology Gwangju 506-824 Korea Dept. of Mechanical Engineering Mokpo National University Mokpo 534-729 Korea

Rotary bending fatigue tests were carried out with two kinds of materials, s43C and s50C, using the front engine and front drive shaft （FF shaft） of vehicle. The specimens were induction hardened about 1.0mm depth from the specimen surface, and the hardness value on the surface was about HRC56-60. The tested environment temperatures were -30, 25 and 80℃ in order to look over effect of the induction hardening and the environmental temperatures on the fatigue characteristi.s. The fatigue limit of induction hardened specimens increased more about 45% than non-hardened specimens showing that the endurances of s43C and s50C were 98.1 and 107.9MPa in non-hardened samples, 147.1 and 156.9MPa in hardened samplesrespectably. The maximum tensile and compressive stress on the small circular defect was about ＋250 and -450MPa respectively when circular defect is situated on top and bottom. The fatigue life increased 80, 25 and -30℃ in order regardless of hardening. in comparison of the fatigue lives on the basis of tested result at 25℃, the fatigue lives of non-hardened specimens decreased about 35%, but that of hardened specimens decreased about only 5% at 80℃ more than at 25℃. And fatigue life of non-hardened and hardened specimens were about 110% and 120% higher at -30℃ than that of 25℃. Based on the result of stress distribution near the defect, the tensile and compressive stress repeatedly generated by load direction were the largest on the small circular defect due to the stress concentration.

关键词： induction hardening fatigue test front engine and front drive shaft,fatigue crack fatigue life fatigue life ratio

sHRiMP U-Pb Dating of Zircons of a Dark Eclogite and a Garnet-bearing Gnei.s.c Granitic Rock from Bixiling,Eastern Dabie Area,Anhui Province:isotope Chronological Evidence of Neoproterozoic UHP Metamorphism

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Acta Geologica sinica(English Edition) 2000年第4期74卷 748-765页

作者： CHENG Yuqi LiU Dunyi i.s. WiLLiAMs JiAN Ping ZHUANG Yuxun GAO Tianshan i.s.itute of Geology Chinese Academy of Geological SciencesBeijing 100037China Research school of Earth sciences Australian National UniversityAustralia Anhui Geological survey Hefei 230011AnhuiChina

The paper reports sHRiMP U-Pb zircon data of a dark eclogite and a post-eclogite garnet-bearing gnei.s.c granitic rock from the Bixiling area, Yuexi County, Anhui Province, in the eastern Dabie Mountai.s. The eclogite, which is metamorphosed basic tuff, contai.s.very scarce zircons in omphacite or garnet, but more zircons in quartz. They usually exhibit a double-layered texture, as shown clearly in cathodoluminescence images. Their inner main parts give a 206Pb/238U age of 757±7 Ma, representing the approximate age of the high-pressure (HP)- ultrahigh-pressure (UHP) metamorphic event during which the eclogite was formed. The outer peripheral parts of the zircons, which have been modified by late-stage flui.s. give an age of 223±3 Ma. The granitic rock contai.s.more zircons of anatectic origin found mostly in feldspar and quartz and usually also showing a similar composite texture. The inner main parts of the anatectic zircons with oscillatory zoning give a 206Pb/238U age of 727±15 Ma for the approximate age of the emplacement of the granitic rock, and their outer parts, an age of 219±3 Ma for a similar or even the same fluid event. it is thus suggested that the HP-UHP metamorphism of the Bixiling eclogite faci.s.rocks took place during the Neoproterozoic Jinningian, and the indosinian age values may only represent a late event in the nature of fluid activity.

关键词： Bixiling dark eclogite garnet-bearing gnei.s.c granitic rock Neoproterozoic Jinningian sHRiMP dating

Rare Earth Elements in Egyptian Phosphorites

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Chinese Journal Of Geochemistry 2002年第1期21卷 19-28页

作者： i.s. isMAEL(Central Metallurgical R & D i.s.itute, P.O. Box 87 Helwan, Cairo, Egypt) Central Metallurgical R & D i.s.itute Cairo Egypt

Egyptian phosphorites from Abu Tartur (Western Desert), El Mahamide mine (Nile Valley) and Rabah mine (Eastern Desert) show variable degrees of relative REE enrichment. Black plateau phosphorites of Abu Tartur are substantially enriched in REE as compared to the Red sea and Nile Valley phosphorites. P-rich organic matter from the Abu Tartur and Rabah mines recorded negative Ce and positive Eu anomali.s. Positive Eu anomaly reveals an anoxic event prior to the phase of Late Cretaceous phosphate formation. Ce is a redox indicator. Mixing of sea water and upwelling during the Late Cretaceous was responsible for the recording of positive Eu and negative Ce anomali.s.in the Egyptian phosphorites.

关键词：稀土元素磷灰石埃及 REE

Zoning of Far Eastern seas of Russia for integrated Nature Management

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Journal of Environmental science and Engineering 2010年第12期4卷 57-63页

作者： i.s. Arzamastsev Pacific Geographical i.s.itute FEBRAs 690041 7 Radio st. Vladivistok Russia

On the Pacific coast of Russia implementation of the methodology of the integrated nature management has a number of peculiariti.s. On the one hand, these districts are characterized by severe hydrometeorological conditions. On the other hand, Russia has no applicable legislation on coastal i.s.es. Thus, to prepare informational, theoretical and methodical bases for organization of sustained nature management in coastal zones of the Russian Federation, we developed hierarchy structure of delimitation of coastal areas and recommendations for their development on the basis of nature resource and social-economic zoning. Zoning of the Russian Far East is suggested to include two major directions：（1） planning of sustainable development of the region and （2） solving contradictions between fisheri.s.and productions of oil and gas in the coastal zones.

关键词： Coastal zone shelf integrated management delimitation zoning boundary hierarchy scheme

Extent of hyperparasitism due to Tetrastichus coccinelliae under different crop habitats

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Extent of hyperparasitism due to Tetrastichus coccinelliae u...

5th international Workshop on Management of the Diamondback Moth and Other Crucifer i.s.ct Pests

作者： PATEL R.A. PATEL i.s. Department of Entomology College of AgricultureAgricultural University S.K.Nagar-385 506.BanaskanthaGujaratIndia.

Mustard aphid,Lipaphis erysimi Kalt.,is one of the major limiting factors for mustard *** yield losses due to this pest varied from 35.42 to 96.00% depending upon the seasons(Bakhetia,1984).Various bioagents of mustard aphid have been reported by Patel et al.(1976) and Kulkarni(2000).Among the i.s.cts predaceous on aphi.s.Coccinella septiimpunctala *** considered to be an efficient

关键词： Extent of hyperparasitism due to Tetrastichus coccinelliae under different crop habitats

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白令海峡两岸民族之联系

世界民族 1994年第4期 68-71页

作者： i.s.古尔维奇关继红

西伯利亚北部和北美西北部文化的相似性,很久以前就吸引着许多考古学家、民族志学家和历史学家的注意。这些相似性为研究古代文化和历史的关系与发展,以及居住在这片广大地区内的民族群体提供了重要的信息。显而易见,不论是在遥远的古代... 详细信息

西伯利亚北部和北美西北部文化的相似性,很久以前就吸引着许多考古学家、民族志学家和历史学家的注意。这些相似性为研究古代文化和历史的关系与发展,以及居住在这片广大地区内的民族群体提供了重要的信息。显而易见,不论是在遥远的古代,还是在距我们较近的时期,在白令海峡地区各个民族语言群体之间进行的贸易以及人口的移动,使经济条件发生了变化。当然。

关键词：白令海峡阿拉斯加相似性西伯利亚民族群体奇人各民族古代文化贸易阿留申人