摘要:
A hydrogen storage material includes a nano size material that can be formed in a multi-layered core/shell structure and/or in a nanotabular (or platelet) form.
摘要:
A hydrogen storage material includes a nano size material that can be formed in a multi-layered core/shell structure and/or in a nanotabular (or platelet) form.
摘要:
There is provided a method of purifying single wall carbon nanotubes so as to be able to remove impurities such as a metal catalyst to obtain the single wall carbon nanotubes with high purity. The method includes the first oxidizing step of oxidizing the single wall carbon nanotubes soot 1 containing an impurity with a metal catalyst 2, the first refluxing step of refluxing the single wall carbon nanotubes soot 1 obtained by the first oxidizing step in an acid solution, the second oxidizing step of oxidizing the single wall carbon nanotubes soot 1 obtained by the first refluxing step, and the second refluxing step of refluxing the single wall carbon nanotubes obtained soot 1 by the second oxidizing step in an acid solution. The single wall nanotubes 1 are synthesized by an arc discharge with a carbon electrode containing a metal catalyst 2. The carbon electrode contains a metal catalyst which consists of Ni, Y, and Ti. The first oxidizing step is performed by heating at a temperature between 350 and 600° C. or by a wet-oxidization in hydrogen peroxide solution. The first refluxing step is performed by refluxing in nitric acid. The second oxidizing step is performed by wet-oxidizing in hydrogen peroxide. The second refluxing step is performed by refluxing in hydrochloric acid.
摘要:
Carbon structures, e.g. carbon nano-fibers, suitable for absorbing hydrogen at low pressures and low temperatures are produced by a selective oxidation and/or acid reflux process. The process includes heating an impure mixture containing a crystalline form of carbon in the presence of an oxidizing gas at a temperature and time sufficient to selectively oxidize and remove a substantial amount of any amorphous carbon impurities from the mixture. Metal containing impurities can be removed from the mixture by exposing the desired carbon and accompanying impurities to an acid to produce a carbon fiber that is substantially free of both non-fiber carbon impurities and metal impurities. Another aspect of the present invention includes purified carbon structures that can store hydrogen at low pressures and temperatures.
摘要:
A high strength and high ductility TiAl-based intermetallic compound includes a content of aluminum in a range represented by 42.0 atom %.ltoreq.Al.ltoreq.50.0 atom %, a content of vanadium in a range represented by 1.0 atom %.ltoreq.V.ltoreq.3.0 atom %, a content of niobium in a range represented by 1.0 atom %.ltoreq.Nb.ltoreq.10.0 atom %, a content of boron in a range represented by 0.03 atom %.ltoreq.B.ltoreq.2.2 atom %, and the balance of titanium and unavoidable impurities. A product of the TiAl-based intermetallic compound is formed by only casting or casting followed by a homogenizing thermal treatment.
摘要翻译:高强度和高延展性的TiAl基金属间化合物包括由42.0原子%Al≤50.0原子%表示的范围内的铝含量,以1.0原子%表示的范围内的钒的含量< V <3.0原子%,以1.0原子%表示的范围内的铌的含量<10.0原子%,以0.03原子%表示的范围内的硼的含量 B = 2.2原子%,其余为钛和不可避免的杂质。 TiAl基金属间化合物的产物仅通过铸造或铸造形成,然后进行均化热处理。
摘要:
A TiAl-based intermetallic compound has a metallographic structure which includes a region A having fine .beta.-phases dispersed in a .gamma.-phase. The volume fraction Vf of the .beta.-phases in the region A is set equal to or more than 0.1% (Vf.gtoreq.0.1%). Thus, the .beta.-phases can exhibit a pinning effect to prevent a transgranular pseudo cleavage fracture in the .gamma.-phase, thereby providing an enhanced high-temperature strength of the TiAl-based intermetallic compound.