Being aimed to developing intermetallic base structural materials to be worked at above 1000℃, a systematic investigation has been performed of the fundamental crystallographic structure, phase constitution map, density-composition dependence, oxidation resistance and general mechanical behaviour for the ternary intermetallic alloys in the Nb-Ti-Al system. Promissing results have been obtained at the initial stage in the current program. The 1100℃ high temperature strength at the strain rate of 10-2/s and 10-5/s for the ternary compound NbTiAl3 （γ1） base alloys are generally much higher than that of the binary compound TiAl （γ）, especially in the γ1 + α2 phase region, it is as high as twice as that of TiAl. The densities are 4.1-4.79g/cm3, depending on relative amount of the intermetallics involved and the density difference between the intermetallics. The oxidation resistance at th
Chapter 5 Electronic commerce information's search and selection In physical markets, consumer search activities include reading advertisements, calling endors, and visiting stores. In a virtual marketplace, all these activities seem to converge into Web searches and Web browsing. Not surprisingly, search services are the first market infrastructure to be built in the electronic marketplace
Introduction: Earth's' Internal-- Thermal Engine Magma is molten rock beneath Earth's surface. Because liquid magma is less dense than surrounding solid rock, and obviously more mobile, magma, once formed, rises toward the surface. Magma that reaches the surface does so by erupting through vents we call volcanoes
Syllabus of Physical Geology Chapter 1 meet planet earth Chapter 2: Global Tectonics, Our Dynamic Planet oChapter 3: Atoms, Elements, Minerals, Rocks: EarthsBuilding materials Chapter 4: Igneous Rocks: Product of Earth's Internal fire Chapter 5: Magma And volcanoes Chapter 6: Weathering and soils Chapter 7: Sediments and Sedimentary rocks Chapter 8: Metamorphism and Metamorphic rock Chapter 9: How rock Bends, Buckles, and Breaks Chapter 10: Earthquakes and Earth's Interior Chapter 11: Geologic Time And The rock record Chapter 12: The Earth Through Time
